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go/src/cmd/compile/internal/gc/ssa.go
Cherry Zhang c4ef597c47 cmd/compile: redo writebarrier pass 
SSA's writebarrier pass requires WB store ops are always at the
end of a block. If we move write barrier insertion into SSA and
emits normal Store ops when building SSA, this requirement becomes
impractical -- it will create too many blocks for all the Store
ops.

Redo SSA's writebarrier pass, explicitly order values in store
order, so it no longer needs this requirement.

Updates #17583.
Fixes #19067.

Change-Id: I66e817e526affb7e13517d4245905300a90b7170
Reviewed-on: https://go-review.googlesource.com/36834
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2017-02-17 19:20:25 +00:00

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// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package gc
import (
"bytes"
"encoding/binary"
"fmt"
"html"
"os"
"sort"
"cmd/compile/internal/ssa"
"cmd/internal/obj"
"cmd/internal/src"
"cmd/internal/sys"
)
var ssaConfig *ssa.Config
var ssaExp ssaExport
func initssa() *ssa.Config {
if ssaConfig == nil {
ssaConfig = ssa.NewConfig(Thearch.LinkArch.Name, &ssaExp, Ctxt, Debug['N'] == 0)
if Thearch.LinkArch.Name == "386" {
ssaConfig.Set387(Thearch.Use387)
}
}
ssaConfig.HTML = nil
return ssaConfig
}
// buildssa builds an SSA function.
func buildssa(fn *Node) *ssa.Func {
name := fn.Func.Nname.Sym.Name
printssa := name == os.Getenv("GOSSAFUNC")
if printssa {
fmt.Println("generating SSA for", name)
dumplist("buildssa-enter", fn.Func.Enter)
dumplist("buildssa-body", fn.Nbody)
dumplist("buildssa-exit", fn.Func.Exit)
}
var s state
s.pushLine(fn.Pos)
defer s.popLine()
if fn.Func.Pragma&CgoUnsafeArgs != 0 {
s.cgoUnsafeArgs = true
}
if fn.Func.Pragma&Nowritebarrier != 0 {
s.noWB = true
}
defer func() {
if s.WBPos.IsKnown() {
fn.Func.WBPos = s.WBPos
}
}()
// TODO(khr): build config just once at the start of the compiler binary
ssaExp.log = printssa
s.config = initssa()
s.f = s.config.NewFunc()
s.f.Name = name
if fn.Func.Pragma&Nosplit != 0 {
s.f.NoSplit = true
}
s.exitCode = fn.Func.Exit
s.panics = map[funcLine]*ssa.Block{}
s.config.DebugTest = s.config.DebugHashMatch("GOSSAHASH", name)
if name == os.Getenv("GOSSAFUNC") {
// TODO: tempfile? it is handy to have the location
// of this file be stable, so you can just reload in the browser.
s.config.HTML = ssa.NewHTMLWriter("ssa.html", s.config, name)
// TODO: generate and print a mapping from nodes to values and blocks
}
// Allocate starting block
s.f.Entry = s.f.NewBlock(ssa.BlockPlain)
// Allocate starting values
s.labels = map[string]*ssaLabel{}
s.labeledNodes = map[*Node]*ssaLabel{}
s.fwdVars = map[*Node]*ssa.Value{}
s.startmem = s.entryNewValue0(ssa.OpInitMem, ssa.TypeMem)
s.sp = s.entryNewValue0(ssa.OpSP, Types[TUINTPTR]) // TODO: use generic pointer type (unsafe.Pointer?) instead
s.sb = s.entryNewValue0(ssa.OpSB, Types[TUINTPTR])
s.startBlock(s.f.Entry)
s.vars[&memVar] = s.startmem
s.varsyms = map[*Node]interface{}{}
// Generate addresses of local declarations
s.decladdrs = map[*Node]*ssa.Value{}
for _, n := range fn.Func.Dcl {
switch n.Class {
case PPARAM, PPARAMOUT:
aux := s.lookupSymbol(n, &ssa.ArgSymbol{Typ: n.Type, Node: n})
s.decladdrs[n] = s.entryNewValue1A(ssa.OpAddr, ptrto(n.Type), aux, s.sp)
if n.Class == PPARAMOUT && s.canSSA(n) {
// Save ssa-able PPARAMOUT variables so we can
// store them back to the stack at the end of
// the function.
s.returns = append(s.returns, n)
}
case PAUTO:
// processed at each use, to prevent Addr coming
// before the decl.
case PAUTOHEAP:
// moved to heap - already handled by frontend
case PFUNC:
// local function - already handled by frontend
default:
s.Fatalf("local variable with class %s unimplemented", classnames[n.Class])
}
}
// Populate SSAable arguments.
for _, n := range fn.Func.Dcl {
if n.Class == PPARAM && s.canSSA(n) {
s.vars[n] = s.newValue0A(ssa.OpArg, n.Type, n)
}
}
// Convert the AST-based IR to the SSA-based IR
s.stmtList(fn.Func.Enter)
s.stmtList(fn.Nbody)
// fallthrough to exit
if s.curBlock != nil {
s.pushLine(fn.Func.Endlineno)
s.exit()
s.popLine()
}
// Check that we used all labels
for name, lab := range s.labels {
if !lab.used() && !lab.reported && !lab.defNode.Used {
yyerrorl(lab.defNode.Pos, "label %v defined and not used", name)
lab.reported = true
}
if lab.used() && !lab.defined() && !lab.reported {
yyerrorl(lab.useNode.Pos, "label %v not defined", name)
lab.reported = true
}
}
// Check any forward gotos. Non-forward gotos have already been checked.
for _, n := range s.fwdGotos {
lab := s.labels[n.Left.Sym.Name]
// If the label is undefined, we have already have printed an error.
if lab.defined() {
s.checkgoto(n, lab.defNode)
}
}
if nerrors > 0 {
s.f.Free()
return nil
}
s.insertPhis()
// Don't carry reference this around longer than necessary
s.exitCode = Nodes{}
// Main call to ssa package to compile function
ssa.Compile(s.f)
return s.f
}
type state struct {
// configuration (arch) information
config *ssa.Config
// function we're building
f *ssa.Func
// labels and labeled control flow nodes (OFOR, OSWITCH, OSELECT) in f
labels map[string]*ssaLabel
labeledNodes map[*Node]*ssaLabel
// gotos that jump forward; required for deferred checkgoto calls
fwdGotos []*Node
// Code that must precede any return
// (e.g., copying value of heap-escaped paramout back to true paramout)
exitCode Nodes
// unlabeled break and continue statement tracking
breakTo *ssa.Block // current target for plain break statement
continueTo *ssa.Block // current target for plain continue statement
// current location where we're interpreting the AST
curBlock *ssa.Block
// variable assignments in the current block (map from variable symbol to ssa value)
// *Node is the unique identifier (an ONAME Node) for the variable.
// TODO: keep a single varnum map, then make all of these maps slices instead?
vars map[*Node]*ssa.Value
// fwdVars are variables that are used before they are defined in the current block.
// This map exists just to coalesce multiple references into a single FwdRef op.
// *Node is the unique identifier (an ONAME Node) for the variable.
fwdVars map[*Node]*ssa.Value
// all defined variables at the end of each block. Indexed by block ID.
defvars []map[*Node]*ssa.Value
// addresses of PPARAM and PPARAMOUT variables.
decladdrs map[*Node]*ssa.Value
// symbols for PEXTERN, PAUTO and PPARAMOUT variables so they can be reused.
varsyms map[*Node]interface{}
// starting values. Memory, stack pointer, and globals pointer
startmem *ssa.Value
sp *ssa.Value
sb *ssa.Value
// line number stack. The current line number is top of stack
line []src.XPos
// list of panic calls by function name and line number.
// Used to deduplicate panic calls.
panics map[funcLine]*ssa.Block
// list of PPARAMOUT (return) variables.
returns []*Node
// A dummy value used during phi construction.
placeholder *ssa.Value
cgoUnsafeArgs bool
noWB bool
WBPos src.XPos // line number of first write barrier. 0=no write barriers
}
type funcLine struct {
f *obj.LSym
line src.XPos
}
type ssaLabel struct {
target *ssa.Block // block identified by this label
breakTarget *ssa.Block // block to break to in control flow node identified by this label
continueTarget *ssa.Block // block to continue to in control flow node identified by this label
defNode *Node // label definition Node (OLABEL)
// Label use Node (OGOTO, OBREAK, OCONTINUE).
// Used only for error detection and reporting.
// There might be multiple uses, but we only need to track one.
useNode *Node
reported bool // reported indicates whether an error has already been reported for this label
}
// defined reports whether the label has a definition (OLABEL node).
func (l *ssaLabel) defined() bool { return l.defNode != nil }
// used reports whether the label has a use (OGOTO, OBREAK, or OCONTINUE node).
func (l *ssaLabel) used() bool { return l.useNode != nil }
// label returns the label associated with sym, creating it if necessary.
func (s *state) label(sym *Sym) *ssaLabel {
lab := s.labels[sym.Name]
if lab == nil {
lab = new(ssaLabel)
s.labels[sym.Name] = lab
}
return lab
}
func (s *state) Logf(msg string, args ...interface{}) { s.config.Logf(msg, args...) }
func (s *state) Log() bool { return s.config.Log() }
func (s *state) Fatalf(msg string, args ...interface{}) { s.config.Fatalf(s.peekPos(), msg, args...) }
func (s *state) Warnl(pos src.XPos, msg string, args ...interface{}) {
s.config.Warnl(pos, msg, args...)
}
func (s *state) Debug_checknil() bool { return s.config.Debug_checknil() }
var (
// dummy node for the memory variable
memVar = Node{Op: ONAME, Class: Pxxx, Sym: &Sym{Name: "mem"}}
// dummy nodes for temporary variables
ptrVar = Node{Op: ONAME, Class: Pxxx, Sym: &Sym{Name: "ptr"}}
lenVar = Node{Op: ONAME, Class: Pxxx, Sym: &Sym{Name: "len"}}
newlenVar = Node{Op: ONAME, Class: Pxxx, Sym: &Sym{Name: "newlen"}}
capVar = Node{Op: ONAME, Class: Pxxx, Sym: &Sym{Name: "cap"}}
typVar = Node{Op: ONAME, Class: Pxxx, Sym: &Sym{Name: "typ"}}
okVar = Node{Op: ONAME, Class: Pxxx, Sym: &Sym{Name: "ok"}}
)
// startBlock sets the current block we're generating code in to b.
func (s *state) startBlock(b *ssa.Block) {
if s.curBlock != nil {
s.Fatalf("starting block %v when block %v has not ended", b, s.curBlock)
}
s.curBlock = b
s.vars = map[*Node]*ssa.Value{}
for n := range s.fwdVars {
delete(s.fwdVars, n)
}
}
// endBlock marks the end of generating code for the current block.
// Returns the (former) current block. Returns nil if there is no current
// block, i.e. if no code flows to the current execution point.
func (s *state) endBlock() *ssa.Block {
b := s.curBlock
if b == nil {
return nil
}
for len(s.defvars) <= int(b.ID) {
s.defvars = append(s.defvars, nil)
}
s.defvars[b.ID] = s.vars
s.curBlock = nil
s.vars = nil
b.Pos = s.peekPos()
return b
}
// pushLine pushes a line number on the line number stack.
func (s *state) pushLine(line src.XPos) {
if !line.IsKnown() {
// the frontend may emit node with line number missing,
// use the parent line number in this case.
line = s.peekPos()
if Debug['K'] != 0 {
Warn("buildssa: unknown position (line 0)")
}
}
s.line = append(s.line, line)
}
// popLine pops the top of the line number stack.
func (s *state) popLine() {
s.line = s.line[:len(s.line)-1]
}
// peekPos peeks the top of the line number stack.
func (s *state) peekPos() src.XPos {
return s.line[len(s.line)-1]
}
func (s *state) Error(msg string, args ...interface{}) {
yyerrorl(s.peekPos(), msg, args...)
}
// newValue0 adds a new value with no arguments to the current block.
func (s *state) newValue0(op ssa.Op, t ssa.Type) *ssa.Value {
return s.curBlock.NewValue0(s.peekPos(), op, t)
}
// newValue0A adds a new value with no arguments and an aux value to the current block.
func (s *state) newValue0A(op ssa.Op, t ssa.Type, aux interface{}) *ssa.Value {
return s.curBlock.NewValue0A(s.peekPos(), op, t, aux)
}
// newValue0I adds a new value with no arguments and an auxint value to the current block.
func (s *state) newValue0I(op ssa.Op, t ssa.Type, auxint int64) *ssa.Value {
return s.curBlock.NewValue0I(s.peekPos(), op, t, auxint)
}
// newValue1 adds a new value with one argument to the current block.
func (s *state) newValue1(op ssa.Op, t ssa.Type, arg *ssa.Value) *ssa.Value {
return s.curBlock.NewValue1(s.peekPos(), op, t, arg)
}
// newValue1A adds a new value with one argument and an aux value to the current block.
func (s *state) newValue1A(op ssa.Op, t ssa.Type, aux interface{}, arg *ssa.Value) *ssa.Value {
return s.curBlock.NewValue1A(s.peekPos(), op, t, aux, arg)
}
// newValue1I adds a new value with one argument and an auxint value to the current block.
func (s *state) newValue1I(op ssa.Op, t ssa.Type, aux int64, arg *ssa.Value) *ssa.Value {
return s.curBlock.NewValue1I(s.peekPos(), op, t, aux, arg)
}
// newValue2 adds a new value with two arguments to the current block.
func (s *state) newValue2(op ssa.Op, t ssa.Type, arg0, arg1 *ssa.Value) *ssa.Value {
return s.curBlock.NewValue2(s.peekPos(), op, t, arg0, arg1)
}
// newValue2I adds a new value with two arguments and an auxint value to the current block.
func (s *state) newValue2I(op ssa.Op, t ssa.Type, aux int64, arg0, arg1 *ssa.Value) *ssa.Value {
return s.curBlock.NewValue2I(s.peekPos(), op, t, aux, arg0, arg1)
}
// newValue3 adds a new value with three arguments to the current block.
func (s *state) newValue3(op ssa.Op, t ssa.Type, arg0, arg1, arg2 *ssa.Value) *ssa.Value {
return s.curBlock.NewValue3(s.peekPos(), op, t, arg0, arg1, arg2)
}
// newValue3I adds a new value with three arguments and an auxint value to the current block.
func (s *state) newValue3I(op ssa.Op, t ssa.Type, aux int64, arg0, arg1, arg2 *ssa.Value) *ssa.Value {
return s.curBlock.NewValue3I(s.peekPos(), op, t, aux, arg0, arg1, arg2)
}
// newValue4 adds a new value with four arguments to the current block.
func (s *state) newValue4(op ssa.Op, t ssa.Type, arg0, arg1, arg2, arg3 *ssa.Value) *ssa.Value {
return s.curBlock.NewValue4(s.peekPos(), op, t, arg0, arg1, arg2, arg3)
}
// entryNewValue0 adds a new value with no arguments to the entry block.
func (s *state) entryNewValue0(op ssa.Op, t ssa.Type) *ssa.Value {
return s.f.Entry.NewValue0(s.peekPos(), op, t)
}
// entryNewValue0A adds a new value with no arguments and an aux value to the entry block.
func (s *state) entryNewValue0A(op ssa.Op, t ssa.Type, aux interface{}) *ssa.Value {
return s.f.Entry.NewValue0A(s.peekPos(), op, t, aux)
}
// entryNewValue0I adds a new value with no arguments and an auxint value to the entry block.
func (s *state) entryNewValue0I(op ssa.Op, t ssa.Type, auxint int64) *ssa.Value {
return s.f.Entry.NewValue0I(s.peekPos(), op, t, auxint)
}
// entryNewValue1 adds a new value with one argument to the entry block.
func (s *state) entryNewValue1(op ssa.Op, t ssa.Type, arg *ssa.Value) *ssa.Value {
return s.f.Entry.NewValue1(s.peekPos(), op, t, arg)
}
// entryNewValue1 adds a new value with one argument and an auxint value to the entry block.
func (s *state) entryNewValue1I(op ssa.Op, t ssa.Type, auxint int64, arg *ssa.Value) *ssa.Value {
return s.f.Entry.NewValue1I(s.peekPos(), op, t, auxint, arg)
}
// entryNewValue1A adds a new value with one argument and an aux value to the entry block.
func (s *state) entryNewValue1A(op ssa.Op, t ssa.Type, aux interface{}, arg *ssa.Value) *ssa.Value {
return s.f.Entry.NewValue1A(s.peekPos(), op, t, aux, arg)
}
// entryNewValue2 adds a new value with two arguments to the entry block.
func (s *state) entryNewValue2(op ssa.Op, t ssa.Type, arg0, arg1 *ssa.Value) *ssa.Value {
return s.f.Entry.NewValue2(s.peekPos(), op, t, arg0, arg1)
}
// const* routines add a new const value to the entry block.
func (s *state) constSlice(t ssa.Type) *ssa.Value { return s.f.ConstSlice(s.peekPos(), t) }
func (s *state) constInterface(t ssa.Type) *ssa.Value { return s.f.ConstInterface(s.peekPos(), t) }
func (s *state) constNil(t ssa.Type) *ssa.Value { return s.f.ConstNil(s.peekPos(), t) }
func (s *state) constEmptyString(t ssa.Type) *ssa.Value { return s.f.ConstEmptyString(s.peekPos(), t) }
func (s *state) constBool(c bool) *ssa.Value {
return s.f.ConstBool(s.peekPos(), Types[TBOOL], c)
}
func (s *state) constInt8(t ssa.Type, c int8) *ssa.Value {
return s.f.ConstInt8(s.peekPos(), t, c)
}
func (s *state) constInt16(t ssa.Type, c int16) *ssa.Value {
return s.f.ConstInt16(s.peekPos(), t, c)
}
func (s *state) constInt32(t ssa.Type, c int32) *ssa.Value {
return s.f.ConstInt32(s.peekPos(), t, c)
}
func (s *state) constInt64(t ssa.Type, c int64) *ssa.Value {
return s.f.ConstInt64(s.peekPos(), t, c)
}
func (s *state) constFloat32(t ssa.Type, c float64) *ssa.Value {
return s.f.ConstFloat32(s.peekPos(), t, c)
}
func (s *state) constFloat64(t ssa.Type, c float64) *ssa.Value {
return s.f.ConstFloat64(s.peekPos(), t, c)
}
func (s *state) constInt(t ssa.Type, c int64) *ssa.Value {
if s.config.IntSize == 8 {
return s.constInt64(t, c)
}
if int64(int32(c)) != c {
s.Fatalf("integer constant too big %d", c)
}
return s.constInt32(t, int32(c))
}
// stmtList converts the statement list n to SSA and adds it to s.
func (s *state) stmtList(l Nodes) {
for _, n := range l.Slice() {
s.stmt(n)
}
}
// stmt converts the statement n to SSA and adds it to s.
func (s *state) stmt(n *Node) {
s.pushLine(n.Pos)
defer s.popLine()
// If s.curBlock is nil, then we're about to generate dead code.
// We can't just short-circuit here, though,
// because we check labels and gotos as part of SSA generation.
// Provide a block for the dead code so that we don't have
// to add special cases everywhere else.
if s.curBlock == nil {
dead := s.f.NewBlock(ssa.BlockPlain)
s.startBlock(dead)
}
s.stmtList(n.Ninit)
switch n.Op {
case OBLOCK:
s.stmtList(n.List)
// No-ops
case OEMPTY, ODCLCONST, ODCLTYPE, OFALL:
// Expression statements
case OCALLFUNC:
if isIntrinsicCall(n) {
s.intrinsicCall(n)
return
}
fallthrough
case OCALLMETH, OCALLINTER:
s.call(n, callNormal)
if n.Op == OCALLFUNC && n.Left.Op == ONAME && n.Left.Class == PFUNC {
if fn := n.Left.Sym.Name; compiling_runtime && fn == "throw" ||
n.Left.Sym.Pkg == Runtimepkg && (fn == "throwinit" || fn == "gopanic" || fn == "panicwrap" || fn == "selectgo" || fn == "block") {
m := s.mem()
b := s.endBlock()
b.Kind = ssa.BlockExit
b.SetControl(m)
// TODO: never rewrite OPANIC to OCALLFUNC in the
// first place. Need to wait until all backends
// go through SSA.
}
}
case ODEFER:
s.call(n.Left, callDefer)
case OPROC:
s.call(n.Left, callGo)
case OAS2DOTTYPE:
res, resok := s.dottype(n.Rlist.First(), true)
deref := false
if !canSSAType(n.Rlist.First().Type) {
if res.Op != ssa.OpLoad {
s.Fatalf("dottype of non-load")
}
mem := s.mem()
if mem.Op == ssa.OpVarKill {
mem = mem.Args[0]
}
if res.Args[1] != mem {
s.Fatalf("memory no longer live from 2-result dottype load")
}
deref = true
res = res.Args[0]
}
s.assign(n.List.First(), res, needwritebarrier(n.List.First()), deref, 0, false)
s.assign(n.List.Second(), resok, false, false, 0, false)
return
case OAS2FUNC:
// We come here only when it is an intrinsic call returning two values.
if !isIntrinsicCall(n.Rlist.First()) {
s.Fatalf("non-intrinsic AS2FUNC not expanded %v", n.Rlist.First())
}
v := s.intrinsicCall(n.Rlist.First())
v1 := s.newValue1(ssa.OpSelect0, n.List.First().Type, v)
v2 := s.newValue1(ssa.OpSelect1, n.List.Second().Type, v)
s.assign(n.List.First(), v1, needwritebarrier(n.List.First()), false, 0, false)
s.assign(n.List.Second(), v2, needwritebarrier(n.List.Second()), false, 0, false)
return
case ODCL:
if n.Left.Class == PAUTOHEAP {
Fatalf("DCL %v", n)
}
case OLABEL:
sym := n.Left.Sym
if isblanksym(sym) {
// Empty identifier is valid but useless.
// See issues 11589, 11593.
return
}
lab := s.label(sym)
// Associate label with its control flow node, if any
if ctl := n.Name.Defn; ctl != nil {
switch ctl.Op {
case OFOR, OSWITCH, OSELECT:
s.labeledNodes[ctl] = lab
}
}
if !lab.defined() {
lab.defNode = n
} else {
s.Error("label %v already defined at %v", sym, linestr(lab.defNode.Pos))
lab.reported = true
}
// The label might already have a target block via a goto.
if lab.target == nil {
lab.target = s.f.NewBlock(ssa.BlockPlain)
}
// go to that label (we pretend "label:" is preceded by "goto label")
b := s.endBlock()
b.AddEdgeTo(lab.target)
s.startBlock(lab.target)
case OGOTO:
sym := n.Left.Sym
lab := s.label(sym)
if lab.target == nil {
lab.target = s.f.NewBlock(ssa.BlockPlain)
}
if !lab.used() {
lab.useNode = n
}
if lab.defined() {
s.checkgoto(n, lab.defNode)
} else {
s.fwdGotos = append(s.fwdGotos, n)
}
b := s.endBlock()
b.AddEdgeTo(lab.target)
case OAS:
// Generate static data rather than code, if possible.
if n.IsStatic {
if !genAsInitNoCheck(n) {
Dump("\ngen_as_init", n)
Fatalf("gen_as_init couldn't generate static data")
}
return
}
if n.Left == n.Right && n.Left.Op == ONAME {
// An x=x assignment. No point in doing anything
// here. In addition, skipping this assignment
// prevents generating:
// VARDEF x
// COPY x -> x
// which is bad because x is incorrectly considered
// dead before the vardef. See issue #14904.
return
}
var t *Type
if n.Right != nil {
t = n.Right.Type
} else {
t = n.Left.Type
}
// Evaluate RHS.
rhs := n.Right
if rhs != nil {
switch rhs.Op {
case OSTRUCTLIT, OARRAYLIT, OSLICELIT:
// All literals with nonzero fields have already been
// rewritten during walk. Any that remain are just T{}
// or equivalents. Use the zero value.
if !iszero(rhs) {
Fatalf("literal with nonzero value in SSA: %v", rhs)
}
rhs = nil
case OAPPEND:
// If we're writing the result of an append back to the same slice,
// handle it specially to avoid write barriers on the fast (non-growth) path.
// If the slice can be SSA'd, it'll be on the stack,
// so there will be no write barriers,
// so there's no need to attempt to prevent them.
if samesafeexpr(n.Left, rhs.List.First()) {
if !s.canSSA(n.Left) {
if Debug_append > 0 {
Warnl(n.Pos, "append: len-only update")
}
s.append(rhs, true)
return
} else {
if Debug_append > 0 { // replicating old diagnostic message
Warnl(n.Pos, "append: len-only update (in local slice)")
}
}
}
}
}
var r *ssa.Value
var isVolatile bool
needwb := n.Right != nil && needwritebarrier(n.Left)
deref := !canSSAType(t)
if deref {
if rhs == nil {
r = nil // Signal assign to use OpZero.
} else {
r, isVolatile = s.addr(rhs, false)
}
} else {
if rhs == nil {
r = s.zeroVal(t)
} else {
r = s.expr(rhs)
}
}
if rhs != nil && rhs.Op == OAPPEND && needwritebarrier(n.Left) {
// The frontend gets rid of the write barrier to enable the special OAPPEND
// handling above, but since this is not a special case, we need it.
// TODO: just add a ptr graying to the end of growslice?
// TODO: check whether we need to provide special handling and a write barrier
// for ODOTTYPE and ORECV also.
// They get similar wb-removal treatment in walk.go:OAS.
needwb = true
}
if needwb && Debug_wb > 1 {
Warnl(n.Pos, "marking %v for barrier", n.Left)
}
var skip skipMask
if rhs != nil && (rhs.Op == OSLICE || rhs.Op == OSLICE3 || rhs.Op == OSLICESTR) && samesafeexpr(rhs.Left, n.Left) {
// We're assigning a slicing operation back to its source.
// Don't write back fields we aren't changing. See issue #14855.
i, j, k := rhs.SliceBounds()
if i != nil && (i.Op == OLITERAL && i.Val().Ctype() == CTINT && i.Int64() == 0) {
// [0:...] is the same as [:...]
i = nil
}
// TODO: detect defaults for len/cap also.
// Currently doesn't really work because (*p)[:len(*p)] appears here as:
// tmp = len(*p)
// (*p)[:tmp]
//if j != nil && (j.Op == OLEN && samesafeexpr(j.Left, n.Left)) {
// j = nil
//}
//if k != nil && (k.Op == OCAP && samesafeexpr(k.Left, n.Left)) {
// k = nil
//}
if i == nil {
skip |= skipPtr
if j == nil {
skip |= skipLen
}
if k == nil {
skip |= skipCap
}
}
}
s.assign(n.Left, r, needwb, deref, skip, isVolatile)
case OIF:
bThen := s.f.NewBlock(ssa.BlockPlain)
bEnd := s.f.NewBlock(ssa.BlockPlain)
var bElse *ssa.Block
if n.Rlist.Len() != 0 {
bElse = s.f.NewBlock(ssa.BlockPlain)
s.condBranch(n.Left, bThen, bElse, n.Likely)
} else {
s.condBranch(n.Left, bThen, bEnd, n.Likely)
}
s.startBlock(bThen)
s.stmtList(n.Nbody)
if b := s.endBlock(); b != nil {
b.AddEdgeTo(bEnd)
}
if n.Rlist.Len() != 0 {
s.startBlock(bElse)
s.stmtList(n.Rlist)
if b := s.endBlock(); b != nil {
b.AddEdgeTo(bEnd)
}
}
s.startBlock(bEnd)
case ORETURN:
s.stmtList(n.List)
s.exit()
case ORETJMP:
s.stmtList(n.List)
b := s.exit()
b.Kind = ssa.BlockRetJmp // override BlockRet
b.Aux = Linksym(n.Left.Sym)
case OCONTINUE, OBREAK:
var op string
var to *ssa.Block
switch n.Op {
case OCONTINUE:
op = "continue"
to = s.continueTo
case OBREAK:
op = "break"
to = s.breakTo
}
if n.Left == nil {
// plain break/continue
if to == nil {
s.Error("%s is not in a loop", op)
return
}
// nothing to do; "to" is already the correct target
} else {
// labeled break/continue; look up the target
sym := n.Left.Sym
lab := s.label(sym)
if !lab.used() {
lab.useNode = n.Left
}
if !lab.defined() {
s.Error("%s label not defined: %v", op, sym)
lab.reported = true
return
}
switch n.Op {
case OCONTINUE:
to = lab.continueTarget
case OBREAK:
to = lab.breakTarget
}
if to == nil {
// Valid label but not usable with a break/continue here, e.g.:
// for {
// continue abc
// }
// abc:
// for {}
s.Error("invalid %s label %v", op, sym)
lab.reported = true
return
}
}
b := s.endBlock()
b.AddEdgeTo(to)
case OFOR:
// OFOR: for Ninit; Left; Right { Nbody }
bCond := s.f.NewBlock(ssa.BlockPlain)
bBody := s.f.NewBlock(ssa.BlockPlain)
bIncr := s.f.NewBlock(ssa.BlockPlain)
bEnd := s.f.NewBlock(ssa.BlockPlain)
// first, jump to condition test
b := s.endBlock()
b.AddEdgeTo(bCond)
// generate code to test condition
s.startBlock(bCond)
if n.Left != nil {
s.condBranch(n.Left, bBody, bEnd, 1)
} else {
b := s.endBlock()
b.Kind = ssa.BlockPlain
b.AddEdgeTo(bBody)
}
// set up for continue/break in body
prevContinue := s.continueTo
prevBreak := s.breakTo
s.continueTo = bIncr
s.breakTo = bEnd
lab := s.labeledNodes[n]
if lab != nil {
// labeled for loop
lab.continueTarget = bIncr
lab.breakTarget = bEnd
}
// generate body
s.startBlock(bBody)
s.stmtList(n.Nbody)
// tear down continue/break
s.continueTo = prevContinue
s.breakTo = prevBreak
if lab != nil {
lab.continueTarget = nil
lab.breakTarget = nil
}
// done with body, goto incr
if b := s.endBlock(); b != nil {
b.AddEdgeTo(bIncr)
}
// generate incr
s.startBlock(bIncr)
if n.Right != nil {
s.stmt(n.Right)
}
if b := s.endBlock(); b != nil {
b.AddEdgeTo(bCond)
}
s.startBlock(bEnd)
case OSWITCH, OSELECT:
// These have been mostly rewritten by the front end into their Nbody fields.
// Our main task is to correctly hook up any break statements.
bEnd := s.f.NewBlock(ssa.BlockPlain)
prevBreak := s.breakTo
s.breakTo = bEnd
lab := s.labeledNodes[n]
if lab != nil {
// labeled
lab.breakTarget = bEnd
}
// generate body code
s.stmtList(n.Nbody)
s.breakTo = prevBreak
if lab != nil {
lab.breakTarget = nil
}
// OSWITCH never falls through (s.curBlock == nil here).
// OSELECT does not fall through if we're calling selectgo.
// OSELECT does fall through if we're calling selectnb{send,recv}[2].
// In those latter cases, go to the code after the select.
if b := s.endBlock(); b != nil {
b.AddEdgeTo(bEnd)
}
s.startBlock(bEnd)
case OVARKILL:
// Insert a varkill op to record that a variable is no longer live.
// We only care about liveness info at call sites, so putting the
// varkill in the store chain is enough to keep it correctly ordered
// with respect to call ops.
if !s.canSSA(n.Left) {
s.vars[&memVar] = s.newValue1A(ssa.OpVarKill, ssa.TypeMem, n.Left, s.mem())
}
case OVARLIVE:
// Insert a varlive op to record that a variable is still live.
if !n.Left.Addrtaken {
s.Fatalf("VARLIVE variable %v must have Addrtaken set", n.Left)
}
s.vars[&memVar] = s.newValue1A(ssa.OpVarLive, ssa.TypeMem, n.Left, s.mem())
case OCHECKNIL:
p := s.expr(n.Left)
s.nilCheck(p)
default:
s.Fatalf("unhandled stmt %v", n.Op)
}
}
// exit processes any code that needs to be generated just before returning.
// It returns a BlockRet block that ends the control flow. Its control value
// will be set to the final memory state.
func (s *state) exit() *ssa.Block {
if hasdefer {
s.rtcall(Deferreturn, true, nil)
}
// Run exit code. Typically, this code copies heap-allocated PPARAMOUT
// variables back to the stack.
s.stmtList(s.exitCode)
// Store SSAable PPARAMOUT variables back to stack locations.
for _, n := range s.returns {
addr := s.decladdrs[n]
val := s.variable(n, n.Type)
s.vars[&memVar] = s.newValue1A(ssa.OpVarDef, ssa.TypeMem, n, s.mem())
s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, n.Type.Size(), addr, val, s.mem())
// TODO: if val is ever spilled, we'd like to use the
// PPARAMOUT slot for spilling it. That won't happen
// currently.
}
// Do actual return.
m := s.mem()
b := s.endBlock()
b.Kind = ssa.BlockRet
b.SetControl(m)
return b
}
type opAndType struct {
op Op
etype EType
}
var opToSSA = map[opAndType]ssa.Op{
opAndType{OADD, TINT8}: ssa.OpAdd8,
opAndType{OADD, TUINT8}: ssa.OpAdd8,
opAndType{OADD, TINT16}: ssa.OpAdd16,
opAndType{OADD, TUINT16}: ssa.OpAdd16,
opAndType{OADD, TINT32}: ssa.OpAdd32,
opAndType{OADD, TUINT32}: ssa.OpAdd32,
opAndType{OADD, TPTR32}: ssa.OpAdd32,
opAndType{OADD, TINT64}: ssa.OpAdd64,
opAndType{OADD, TUINT64}: ssa.OpAdd64,
opAndType{OADD, TPTR64}: ssa.OpAdd64,
opAndType{OADD, TFLOAT32}: ssa.OpAdd32F,
opAndType{OADD, TFLOAT64}: ssa.OpAdd64F,
opAndType{OSUB, TINT8}: ssa.OpSub8,
opAndType{OSUB, TUINT8}: ssa.OpSub8,
opAndType{OSUB, TINT16}: ssa.OpSub16,
opAndType{OSUB, TUINT16}: ssa.OpSub16,
opAndType{OSUB, TINT32}: ssa.OpSub32,
opAndType{OSUB, TUINT32}: ssa.OpSub32,
opAndType{OSUB, TINT64}: ssa.OpSub64,
opAndType{OSUB, TUINT64}: ssa.OpSub64,
opAndType{OSUB, TFLOAT32}: ssa.OpSub32F,
opAndType{OSUB, TFLOAT64}: ssa.OpSub64F,
opAndType{ONOT, TBOOL}: ssa.OpNot,
opAndType{OMINUS, TINT8}: ssa.OpNeg8,
opAndType{OMINUS, TUINT8}: ssa.OpNeg8,
opAndType{OMINUS, TINT16}: ssa.OpNeg16,
opAndType{OMINUS, TUINT16}: ssa.OpNeg16,
opAndType{OMINUS, TINT32}: ssa.OpNeg32,
opAndType{OMINUS, TUINT32}: ssa.OpNeg32,
opAndType{OMINUS, TINT64}: ssa.OpNeg64,
opAndType{OMINUS, TUINT64}: ssa.OpNeg64,
opAndType{OMINUS, TFLOAT32}: ssa.OpNeg32F,
opAndType{OMINUS, TFLOAT64}: ssa.OpNeg64F,
opAndType{OCOM, TINT8}: ssa.OpCom8,
opAndType{OCOM, TUINT8}: ssa.OpCom8,
opAndType{OCOM, TINT16}: ssa.OpCom16,
opAndType{OCOM, TUINT16}: ssa.OpCom16,
opAndType{OCOM, TINT32}: ssa.OpCom32,
opAndType{OCOM, TUINT32}: ssa.OpCom32,
opAndType{OCOM, TINT64}: ssa.OpCom64,
opAndType{OCOM, TUINT64}: ssa.OpCom64,
opAndType{OIMAG, TCOMPLEX64}: ssa.OpComplexImag,
opAndType{OIMAG, TCOMPLEX128}: ssa.OpComplexImag,
opAndType{OREAL, TCOMPLEX64}: ssa.OpComplexReal,
opAndType{OREAL, TCOMPLEX128}: ssa.OpComplexReal,
opAndType{OMUL, TINT8}: ssa.OpMul8,
opAndType{OMUL, TUINT8}: ssa.OpMul8,
opAndType{OMUL, TINT16}: ssa.OpMul16,
opAndType{OMUL, TUINT16}: ssa.OpMul16,
opAndType{OMUL, TINT32}: ssa.OpMul32,
opAndType{OMUL, TUINT32}: ssa.OpMul32,
opAndType{OMUL, TINT64}: ssa.OpMul64,
opAndType{OMUL, TUINT64}: ssa.OpMul64,
opAndType{OMUL, TFLOAT32}: ssa.OpMul32F,
opAndType{OMUL, TFLOAT64}: ssa.OpMul64F,
opAndType{ODIV, TFLOAT32}: ssa.OpDiv32F,
opAndType{ODIV, TFLOAT64}: ssa.OpDiv64F,
opAndType{OHMUL, TINT8}: ssa.OpHmul8,
opAndType{OHMUL, TUINT8}: ssa.OpHmul8u,
opAndType{OHMUL, TINT16}: ssa.OpHmul16,
opAndType{OHMUL, TUINT16}: ssa.OpHmul16u,
opAndType{OHMUL, TINT32}: ssa.OpHmul32,
opAndType{OHMUL, TUINT32}: ssa.OpHmul32u,
opAndType{ODIV, TINT8}: ssa.OpDiv8,
opAndType{ODIV, TUINT8}: ssa.OpDiv8u,
opAndType{ODIV, TINT16}: ssa.OpDiv16,
opAndType{ODIV, TUINT16}: ssa.OpDiv16u,
opAndType{ODIV, TINT32}: ssa.OpDiv32,
opAndType{ODIV, TUINT32}: ssa.OpDiv32u,
opAndType{ODIV, TINT64}: ssa.OpDiv64,
opAndType{ODIV, TUINT64}: ssa.OpDiv64u,
opAndType{OMOD, TINT8}: ssa.OpMod8,
opAndType{OMOD, TUINT8}: ssa.OpMod8u,
opAndType{OMOD, TINT16}: ssa.OpMod16,
opAndType{OMOD, TUINT16}: ssa.OpMod16u,
opAndType{OMOD, TINT32}: ssa.OpMod32,
opAndType{OMOD, TUINT32}: ssa.OpMod32u,
opAndType{OMOD, TINT64}: ssa.OpMod64,
opAndType{OMOD, TUINT64}: ssa.OpMod64u,
opAndType{OAND, TINT8}: ssa.OpAnd8,
opAndType{OAND, TUINT8}: ssa.OpAnd8,
opAndType{OAND, TINT16}: ssa.OpAnd16,
opAndType{OAND, TUINT16}: ssa.OpAnd16,
opAndType{OAND, TINT32}: ssa.OpAnd32,
opAndType{OAND, TUINT32}: ssa.OpAnd32,
opAndType{OAND, TINT64}: ssa.OpAnd64,
opAndType{OAND, TUINT64}: ssa.OpAnd64,
opAndType{OOR, TINT8}: ssa.OpOr8,
opAndType{OOR, TUINT8}: ssa.OpOr8,
opAndType{OOR, TINT16}: ssa.OpOr16,
opAndType{OOR, TUINT16}: ssa.OpOr16,
opAndType{OOR, TINT32}: ssa.OpOr32,
opAndType{OOR, TUINT32}: ssa.OpOr32,
opAndType{OOR, TINT64}: ssa.OpOr64,
opAndType{OOR, TUINT64}: ssa.OpOr64,
opAndType{OXOR, TINT8}: ssa.OpXor8,
opAndType{OXOR, TUINT8}: ssa.OpXor8,
opAndType{OXOR, TINT16}: ssa.OpXor16,
opAndType{OXOR, TUINT16}: ssa.OpXor16,
opAndType{OXOR, TINT32}: ssa.OpXor32,
opAndType{OXOR, TUINT32}: ssa.OpXor32,
opAndType{OXOR, TINT64}: ssa.OpXor64,
opAndType{OXOR, TUINT64}: ssa.OpXor64,
opAndType{OEQ, TBOOL}: ssa.OpEqB,
opAndType{OEQ, TINT8}: ssa.OpEq8,
opAndType{OEQ, TUINT8}: ssa.OpEq8,
opAndType{OEQ, TINT16}: ssa.OpEq16,
opAndType{OEQ, TUINT16}: ssa.OpEq16,
opAndType{OEQ, TINT32}: ssa.OpEq32,
opAndType{OEQ, TUINT32}: ssa.OpEq32,
opAndType{OEQ, TINT64}: ssa.OpEq64,
opAndType{OEQ, TUINT64}: ssa.OpEq64,
opAndType{OEQ, TINTER}: ssa.OpEqInter,
opAndType{OEQ, TSLICE}: ssa.OpEqSlice,
opAndType{OEQ, TFUNC}: ssa.OpEqPtr,
opAndType{OEQ, TMAP}: ssa.OpEqPtr,
opAndType{OEQ, TCHAN}: ssa.OpEqPtr,
opAndType{OEQ, TPTR32}: ssa.OpEqPtr,
opAndType{OEQ, TPTR64}: ssa.OpEqPtr,
opAndType{OEQ, TUINTPTR}: ssa.OpEqPtr,
opAndType{OEQ, TUNSAFEPTR}: ssa.OpEqPtr,
opAndType{OEQ, TFLOAT64}: ssa.OpEq64F,
opAndType{OEQ, TFLOAT32}: ssa.OpEq32F,
opAndType{ONE, TBOOL}: ssa.OpNeqB,
opAndType{ONE, TINT8}: ssa.OpNeq8,
opAndType{ONE, TUINT8}: ssa.OpNeq8,
opAndType{ONE, TINT16}: ssa.OpNeq16,
opAndType{ONE, TUINT16}: ssa.OpNeq16,
opAndType{ONE, TINT32}: ssa.OpNeq32,
opAndType{ONE, TUINT32}: ssa.OpNeq32,
opAndType{ONE, TINT64}: ssa.OpNeq64,
opAndType{ONE, TUINT64}: ssa.OpNeq64,
opAndType{ONE, TINTER}: ssa.OpNeqInter,
opAndType{ONE, TSLICE}: ssa.OpNeqSlice,
opAndType{ONE, TFUNC}: ssa.OpNeqPtr,
opAndType{ONE, TMAP}: ssa.OpNeqPtr,
opAndType{ONE, TCHAN}: ssa.OpNeqPtr,
opAndType{ONE, TPTR32}: ssa.OpNeqPtr,
opAndType{ONE, TPTR64}: ssa.OpNeqPtr,
opAndType{ONE, TUINTPTR}: ssa.OpNeqPtr,
opAndType{ONE, TUNSAFEPTR}: ssa.OpNeqPtr,
opAndType{ONE, TFLOAT64}: ssa.OpNeq64F,
opAndType{ONE, TFLOAT32}: ssa.OpNeq32F,
opAndType{OLT, TINT8}: ssa.OpLess8,
opAndType{OLT, TUINT8}: ssa.OpLess8U,
opAndType{OLT, TINT16}: ssa.OpLess16,
opAndType{OLT, TUINT16}: ssa.OpLess16U,
opAndType{OLT, TINT32}: ssa.OpLess32,
opAndType{OLT, TUINT32}: ssa.OpLess32U,
opAndType{OLT, TINT64}: ssa.OpLess64,
opAndType{OLT, TUINT64}: ssa.OpLess64U,
opAndType{OLT, TFLOAT64}: ssa.OpLess64F,
opAndType{OLT, TFLOAT32}: ssa.OpLess32F,
opAndType{OGT, TINT8}: ssa.OpGreater8,
opAndType{OGT, TUINT8}: ssa.OpGreater8U,
opAndType{OGT, TINT16}: ssa.OpGreater16,
opAndType{OGT, TUINT16}: ssa.OpGreater16U,
opAndType{OGT, TINT32}: ssa.OpGreater32,
opAndType{OGT, TUINT32}: ssa.OpGreater32U,
opAndType{OGT, TINT64}: ssa.OpGreater64,
opAndType{OGT, TUINT64}: ssa.OpGreater64U,
opAndType{OGT, TFLOAT64}: ssa.OpGreater64F,
opAndType{OGT, TFLOAT32}: ssa.OpGreater32F,
opAndType{OLE, TINT8}: ssa.OpLeq8,
opAndType{OLE, TUINT8}: ssa.OpLeq8U,
opAndType{OLE, TINT16}: ssa.OpLeq16,
opAndType{OLE, TUINT16}: ssa.OpLeq16U,
opAndType{OLE, TINT32}: ssa.OpLeq32,
opAndType{OLE, TUINT32}: ssa.OpLeq32U,
opAndType{OLE, TINT64}: ssa.OpLeq64,
opAndType{OLE, TUINT64}: ssa.OpLeq64U,
opAndType{OLE, TFLOAT64}: ssa.OpLeq64F,
opAndType{OLE, TFLOAT32}: ssa.OpLeq32F,
opAndType{OGE, TINT8}: ssa.OpGeq8,
opAndType{OGE, TUINT8}: ssa.OpGeq8U,
opAndType{OGE, TINT16}: ssa.OpGeq16,
opAndType{OGE, TUINT16}: ssa.OpGeq16U,
opAndType{OGE, TINT32}: ssa.OpGeq32,
opAndType{OGE, TUINT32}: ssa.OpGeq32U,
opAndType{OGE, TINT64}: ssa.OpGeq64,
opAndType{OGE, TUINT64}: ssa.OpGeq64U,
opAndType{OGE, TFLOAT64}: ssa.OpGeq64F,
opAndType{OGE, TFLOAT32}: ssa.OpGeq32F,
}
func (s *state) concreteEtype(t *Type) EType {
e := t.Etype
switch e {
default:
return e
case TINT:
if s.config.IntSize == 8 {
return TINT64
}
return TINT32
case TUINT:
if s.config.IntSize == 8 {
return TUINT64
}
return TUINT32
case TUINTPTR:
if s.config.PtrSize == 8 {
return TUINT64
}
return TUINT32
}
}
func (s *state) ssaOp(op Op, t *Type) ssa.Op {
etype := s.concreteEtype(t)
x, ok := opToSSA[opAndType{op, etype}]
if !ok {
s.Fatalf("unhandled binary op %v %s", op, etype)
}
return x
}
func floatForComplex(t *Type) *Type {
if t.Size() == 8 {
return Types[TFLOAT32]
} else {
return Types[TFLOAT64]
}
}
type opAndTwoTypes struct {
op Op
etype1 EType
etype2 EType
}
type twoTypes struct {
etype1 EType
etype2 EType
}
type twoOpsAndType struct {
op1 ssa.Op
op2 ssa.Op
intermediateType EType
}
var fpConvOpToSSA = map[twoTypes]twoOpsAndType{
twoTypes{TINT8, TFLOAT32}: twoOpsAndType{ssa.OpSignExt8to32, ssa.OpCvt32to32F, TINT32},
twoTypes{TINT16, TFLOAT32}: twoOpsAndType{ssa.OpSignExt16to32, ssa.OpCvt32to32F, TINT32},
twoTypes{TINT32, TFLOAT32}: twoOpsAndType{ssa.OpCopy, ssa.OpCvt32to32F, TINT32},
twoTypes{TINT64, TFLOAT32}: twoOpsAndType{ssa.OpCopy, ssa.OpCvt64to32F, TINT64},
twoTypes{TINT8, TFLOAT64}: twoOpsAndType{ssa.OpSignExt8to32, ssa.OpCvt32to64F, TINT32},
twoTypes{TINT16, TFLOAT64}: twoOpsAndType{ssa.OpSignExt16to32, ssa.OpCvt32to64F, TINT32},
twoTypes{TINT32, TFLOAT64}: twoOpsAndType{ssa.OpCopy, ssa.OpCvt32to64F, TINT32},
twoTypes{TINT64, TFLOAT64}: twoOpsAndType{ssa.OpCopy, ssa.OpCvt64to64F, TINT64},
twoTypes{TFLOAT32, TINT8}: twoOpsAndType{ssa.OpCvt32Fto32, ssa.OpTrunc32to8, TINT32},
twoTypes{TFLOAT32, TINT16}: twoOpsAndType{ssa.OpCvt32Fto32, ssa.OpTrunc32to16, TINT32},
twoTypes{TFLOAT32, TINT32}: twoOpsAndType{ssa.OpCvt32Fto32, ssa.OpCopy, TINT32},
twoTypes{TFLOAT32, TINT64}: twoOpsAndType{ssa.OpCvt32Fto64, ssa.OpCopy, TINT64},
twoTypes{TFLOAT64, TINT8}: twoOpsAndType{ssa.OpCvt64Fto32, ssa.OpTrunc32to8, TINT32},
twoTypes{TFLOAT64, TINT16}: twoOpsAndType{ssa.OpCvt64Fto32, ssa.OpTrunc32to16, TINT32},
twoTypes{TFLOAT64, TINT32}: twoOpsAndType{ssa.OpCvt64Fto32, ssa.OpCopy, TINT32},
twoTypes{TFLOAT64, TINT64}: twoOpsAndType{ssa.OpCvt64Fto64, ssa.OpCopy, TINT64},
// unsigned
twoTypes{TUINT8, TFLOAT32}: twoOpsAndType{ssa.OpZeroExt8to32, ssa.OpCvt32to32F, TINT32},
twoTypes{TUINT16, TFLOAT32}: twoOpsAndType{ssa.OpZeroExt16to32, ssa.OpCvt32to32F, TINT32},
twoTypes{TUINT32, TFLOAT32}: twoOpsAndType{ssa.OpZeroExt32to64, ssa.OpCvt64to32F, TINT64}, // go wide to dodge unsigned
twoTypes{TUINT64, TFLOAT32}: twoOpsAndType{ssa.OpCopy, ssa.OpInvalid, TUINT64}, // Cvt64Uto32F, branchy code expansion instead
twoTypes{TUINT8, TFLOAT64}: twoOpsAndType{ssa.OpZeroExt8to32, ssa.OpCvt32to64F, TINT32},
twoTypes{TUINT16, TFLOAT64}: twoOpsAndType{ssa.OpZeroExt16to32, ssa.OpCvt32to64F, TINT32},
twoTypes{TUINT32, TFLOAT64}: twoOpsAndType{ssa.OpZeroExt32to64, ssa.OpCvt64to64F, TINT64}, // go wide to dodge unsigned
twoTypes{TUINT64, TFLOAT64}: twoOpsAndType{ssa.OpCopy, ssa.OpInvalid, TUINT64}, // Cvt64Uto64F, branchy code expansion instead
twoTypes{TFLOAT32, TUINT8}: twoOpsAndType{ssa.OpCvt32Fto32, ssa.OpTrunc32to8, TINT32},
twoTypes{TFLOAT32, TUINT16}: twoOpsAndType{ssa.OpCvt32Fto32, ssa.OpTrunc32to16, TINT32},
twoTypes{TFLOAT32, TUINT32}: twoOpsAndType{ssa.OpCvt32Fto64, ssa.OpTrunc64to32, TINT64}, // go wide to dodge unsigned
twoTypes{TFLOAT32, TUINT64}: twoOpsAndType{ssa.OpInvalid, ssa.OpCopy, TUINT64}, // Cvt32Fto64U, branchy code expansion instead
twoTypes{TFLOAT64, TUINT8}: twoOpsAndType{ssa.OpCvt64Fto32, ssa.OpTrunc32to8, TINT32},
twoTypes{TFLOAT64, TUINT16}: twoOpsAndType{ssa.OpCvt64Fto32, ssa.OpTrunc32to16, TINT32},
twoTypes{TFLOAT64, TUINT32}: twoOpsAndType{ssa.OpCvt64Fto64, ssa.OpTrunc64to32, TINT64}, // go wide to dodge unsigned
twoTypes{TFLOAT64, TUINT64}: twoOpsAndType{ssa.OpInvalid, ssa.OpCopy, TUINT64}, // Cvt64Fto64U, branchy code expansion instead
// float
twoTypes{TFLOAT64, TFLOAT32}: twoOpsAndType{ssa.OpCvt64Fto32F, ssa.OpCopy, TFLOAT32},
twoTypes{TFLOAT64, TFLOAT64}: twoOpsAndType{ssa.OpCopy, ssa.OpCopy, TFLOAT64},
twoTypes{TFLOAT32, TFLOAT32}: twoOpsAndType{ssa.OpCopy, ssa.OpCopy, TFLOAT32},
twoTypes{TFLOAT32, TFLOAT64}: twoOpsAndType{ssa.OpCvt32Fto64F, ssa.OpCopy, TFLOAT64},
}
// this map is used only for 32-bit arch, and only includes the difference
// on 32-bit arch, don't use int64<->float conversion for uint32
var fpConvOpToSSA32 = map[twoTypes]twoOpsAndType{
twoTypes{TUINT32, TFLOAT32}: twoOpsAndType{ssa.OpCopy, ssa.OpCvt32Uto32F, TUINT32},
twoTypes{TUINT32, TFLOAT64}: twoOpsAndType{ssa.OpCopy, ssa.OpCvt32Uto64F, TUINT32},
twoTypes{TFLOAT32, TUINT32}: twoOpsAndType{ssa.OpCvt32Fto32U, ssa.OpCopy, TUINT32},
twoTypes{TFLOAT64, TUINT32}: twoOpsAndType{ssa.OpCvt64Fto32U, ssa.OpCopy, TUINT32},
}
// uint64<->float conversions, only on machines that have intructions for that
var uint64fpConvOpToSSA = map[twoTypes]twoOpsAndType{
twoTypes{TUINT64, TFLOAT32}: twoOpsAndType{ssa.OpCopy, ssa.OpCvt64Uto32F, TUINT64},
twoTypes{TUINT64, TFLOAT64}: twoOpsAndType{ssa.OpCopy, ssa.OpCvt64Uto64F, TUINT64},
twoTypes{TFLOAT32, TUINT64}: twoOpsAndType{ssa.OpCvt32Fto64U, ssa.OpCopy, TUINT64},
twoTypes{TFLOAT64, TUINT64}: twoOpsAndType{ssa.OpCvt64Fto64U, ssa.OpCopy, TUINT64},
}
var shiftOpToSSA = map[opAndTwoTypes]ssa.Op{
opAndTwoTypes{OLSH, TINT8, TUINT8}: ssa.OpLsh8x8,
opAndTwoTypes{OLSH, TUINT8, TUINT8}: ssa.OpLsh8x8,
opAndTwoTypes{OLSH, TINT8, TUINT16}: ssa.OpLsh8x16,
opAndTwoTypes{OLSH, TUINT8, TUINT16}: ssa.OpLsh8x16,
opAndTwoTypes{OLSH, TINT8, TUINT32}: ssa.OpLsh8x32,
opAndTwoTypes{OLSH, TUINT8, TUINT32}: ssa.OpLsh8x32,
opAndTwoTypes{OLSH, TINT8, TUINT64}: ssa.OpLsh8x64,
opAndTwoTypes{OLSH, TUINT8, TUINT64}: ssa.OpLsh8x64,
opAndTwoTypes{OLSH, TINT16, TUINT8}: ssa.OpLsh16x8,
opAndTwoTypes{OLSH, TUINT16, TUINT8}: ssa.OpLsh16x8,
opAndTwoTypes{OLSH, TINT16, TUINT16}: ssa.OpLsh16x16,
opAndTwoTypes{OLSH, TUINT16, TUINT16}: ssa.OpLsh16x16,
opAndTwoTypes{OLSH, TINT16, TUINT32}: ssa.OpLsh16x32,
opAndTwoTypes{OLSH, TUINT16, TUINT32}: ssa.OpLsh16x32,
opAndTwoTypes{OLSH, TINT16, TUINT64}: ssa.OpLsh16x64,
opAndTwoTypes{OLSH, TUINT16, TUINT64}: ssa.OpLsh16x64,
opAndTwoTypes{OLSH, TINT32, TUINT8}: ssa.OpLsh32x8,
opAndTwoTypes{OLSH, TUINT32, TUINT8}: ssa.OpLsh32x8,
opAndTwoTypes{OLSH, TINT32, TUINT16}: ssa.OpLsh32x16,
opAndTwoTypes{OLSH, TUINT32, TUINT16}: ssa.OpLsh32x16,
opAndTwoTypes{OLSH, TINT32, TUINT32}: ssa.OpLsh32x32,
opAndTwoTypes{OLSH, TUINT32, TUINT32}: ssa.OpLsh32x32,
opAndTwoTypes{OLSH, TINT32, TUINT64}: ssa.OpLsh32x64,
opAndTwoTypes{OLSH, TUINT32, TUINT64}: ssa.OpLsh32x64,
opAndTwoTypes{OLSH, TINT64, TUINT8}: ssa.OpLsh64x8,
opAndTwoTypes{OLSH, TUINT64, TUINT8}: ssa.OpLsh64x8,
opAndTwoTypes{OLSH, TINT64, TUINT16}: ssa.OpLsh64x16,
opAndTwoTypes{OLSH, TUINT64, TUINT16}: ssa.OpLsh64x16,
opAndTwoTypes{OLSH, TINT64, TUINT32}: ssa.OpLsh64x32,
opAndTwoTypes{OLSH, TUINT64, TUINT32}: ssa.OpLsh64x32,
opAndTwoTypes{OLSH, TINT64, TUINT64}: ssa.OpLsh64x64,
opAndTwoTypes{OLSH, TUINT64, TUINT64}: ssa.OpLsh64x64,
opAndTwoTypes{ORSH, TINT8, TUINT8}: ssa.OpRsh8x8,
opAndTwoTypes{ORSH, TUINT8, TUINT8}: ssa.OpRsh8Ux8,
opAndTwoTypes{ORSH, TINT8, TUINT16}: ssa.OpRsh8x16,
opAndTwoTypes{ORSH, TUINT8, TUINT16}: ssa.OpRsh8Ux16,
opAndTwoTypes{ORSH, TINT8, TUINT32}: ssa.OpRsh8x32,
opAndTwoTypes{ORSH, TUINT8, TUINT32}: ssa.OpRsh8Ux32,
opAndTwoTypes{ORSH, TINT8, TUINT64}: ssa.OpRsh8x64,
opAndTwoTypes{ORSH, TUINT8, TUINT64}: ssa.OpRsh8Ux64,
opAndTwoTypes{ORSH, TINT16, TUINT8}: ssa.OpRsh16x8,
opAndTwoTypes{ORSH, TUINT16, TUINT8}: ssa.OpRsh16Ux8,
opAndTwoTypes{ORSH, TINT16, TUINT16}: ssa.OpRsh16x16,
opAndTwoTypes{ORSH, TUINT16, TUINT16}: ssa.OpRsh16Ux16,
opAndTwoTypes{ORSH, TINT16, TUINT32}: ssa.OpRsh16x32,
opAndTwoTypes{ORSH, TUINT16, TUINT32}: ssa.OpRsh16Ux32,
opAndTwoTypes{ORSH, TINT16, TUINT64}: ssa.OpRsh16x64,
opAndTwoTypes{ORSH, TUINT16, TUINT64}: ssa.OpRsh16Ux64,
opAndTwoTypes{ORSH, TINT32, TUINT8}: ssa.OpRsh32x8,
opAndTwoTypes{ORSH, TUINT32, TUINT8}: ssa.OpRsh32Ux8,
opAndTwoTypes{ORSH, TINT32, TUINT16}: ssa.OpRsh32x16,
opAndTwoTypes{ORSH, TUINT32, TUINT16}: ssa.OpRsh32Ux16,
opAndTwoTypes{ORSH, TINT32, TUINT32}: ssa.OpRsh32x32,
opAndTwoTypes{ORSH, TUINT32, TUINT32}: ssa.OpRsh32Ux32,
opAndTwoTypes{ORSH, TINT32, TUINT64}: ssa.OpRsh32x64,
opAndTwoTypes{ORSH, TUINT32, TUINT64}: ssa.OpRsh32Ux64,
opAndTwoTypes{ORSH, TINT64, TUINT8}: ssa.OpRsh64x8,
opAndTwoTypes{ORSH, TUINT64, TUINT8}: ssa.OpRsh64Ux8,
opAndTwoTypes{ORSH, TINT64, TUINT16}: ssa.OpRsh64x16,
opAndTwoTypes{ORSH, TUINT64, TUINT16}: ssa.OpRsh64Ux16,
opAndTwoTypes{ORSH, TINT64, TUINT32}: ssa.OpRsh64x32,
opAndTwoTypes{ORSH, TUINT64, TUINT32}: ssa.OpRsh64Ux32,
opAndTwoTypes{ORSH, TINT64, TUINT64}: ssa.OpRsh64x64,
opAndTwoTypes{ORSH, TUINT64, TUINT64}: ssa.OpRsh64Ux64,
}
func (s *state) ssaShiftOp(op Op, t *Type, u *Type) ssa.Op {
etype1 := s.concreteEtype(t)
etype2 := s.concreteEtype(u)
x, ok := shiftOpToSSA[opAndTwoTypes{op, etype1, etype2}]
if !ok {
s.Fatalf("unhandled shift op %v etype=%s/%s", op, etype1, etype2)
}
return x
}
// expr converts the expression n to ssa, adds it to s and returns the ssa result.
func (s *state) expr(n *Node) *ssa.Value {
if !(n.Op == ONAME || n.Op == OLITERAL && n.Sym != nil) {
// ONAMEs and named OLITERALs have the line number
// of the decl, not the use. See issue 14742.
s.pushLine(n.Pos)
defer s.popLine()
}
s.stmtList(n.Ninit)
switch n.Op {
case OARRAYBYTESTRTMP:
slice := s.expr(n.Left)
ptr := s.newValue1(ssa.OpSlicePtr, ptrto(Types[TUINT8]), slice)
len := s.newValue1(ssa.OpSliceLen, Types[TINT], slice)
return s.newValue2(ssa.OpStringMake, n.Type, ptr, len)
case OSTRARRAYBYTETMP:
str := s.expr(n.Left)
ptr := s.newValue1(ssa.OpStringPtr, ptrto(Types[TUINT8]), str)
len := s.newValue1(ssa.OpStringLen, Types[TINT], str)
return s.newValue3(ssa.OpSliceMake, n.Type, ptr, len, len)
case OCFUNC:
aux := s.lookupSymbol(n, &ssa.ExternSymbol{Typ: n.Type, Sym: Linksym(n.Left.Sym)})
return s.entryNewValue1A(ssa.OpAddr, n.Type, aux, s.sb)
case ONAME:
if n.Class == PFUNC {
// "value" of a function is the address of the function's closure
sym := Linksym(funcsym(n.Sym))
aux := &ssa.ExternSymbol{Typ: n.Type, Sym: sym}
return s.entryNewValue1A(ssa.OpAddr, ptrto(n.Type), aux, s.sb)
}
if s.canSSA(n) {
return s.variable(n, n.Type)
}
addr, _ := s.addr(n, false)
return s.newValue2(ssa.OpLoad, n.Type, addr, s.mem())
case OCLOSUREVAR:
addr, _ := s.addr(n, false)
return s.newValue2(ssa.OpLoad, n.Type, addr, s.mem())
case OLITERAL:
switch u := n.Val().U.(type) {
case *Mpint:
i := u.Int64()
switch n.Type.Size() {
case 1:
return s.constInt8(n.Type, int8(i))
case 2:
return s.constInt16(n.Type, int16(i))
case 4:
return s.constInt32(n.Type, int32(i))
case 8:
return s.constInt64(n.Type, i)
default:
s.Fatalf("bad integer size %d", n.Type.Size())
return nil
}
case string:
if u == "" {
return s.constEmptyString(n.Type)
}
return s.entryNewValue0A(ssa.OpConstString, n.Type, u)
case bool:
return s.constBool(u)
case *NilVal:
t := n.Type
switch {
case t.IsSlice():
return s.constSlice(t)
case t.IsInterface():
return s.constInterface(t)
default:
return s.constNil(t)
}
case *Mpflt:
switch n.Type.Size() {
case 4:
return s.constFloat32(n.Type, u.Float32())
case 8:
return s.constFloat64(n.Type, u.Float64())
default:
s.Fatalf("bad float size %d", n.Type.Size())
return nil
}
case *Mpcplx:
r := &u.Real
i := &u.Imag
switch n.Type.Size() {
case 8:
pt := Types[TFLOAT32]
return s.newValue2(ssa.OpComplexMake, n.Type,
s.constFloat32(pt, r.Float32()),
s.constFloat32(pt, i.Float32()))
case 16:
pt := Types[TFLOAT64]
return s.newValue2(ssa.OpComplexMake, n.Type,
s.constFloat64(pt, r.Float64()),
s.constFloat64(pt, i.Float64()))
default:
s.Fatalf("bad float size %d", n.Type.Size())
return nil
}
default:
s.Fatalf("unhandled OLITERAL %v", n.Val().Ctype())
return nil
}
case OCONVNOP:
to := n.Type
from := n.Left.Type
// Assume everything will work out, so set up our return value.
// Anything interesting that happens from here is a fatal.
x := s.expr(n.Left)
// Special case for not confusing GC and liveness.
// We don't want pointers accidentally classified
// as not-pointers or vice-versa because of copy
// elision.
if to.IsPtrShaped() != from.IsPtrShaped() {
return s.newValue2(ssa.OpConvert, to, x, s.mem())
}
v := s.newValue1(ssa.OpCopy, to, x) // ensure that v has the right type
// CONVNOP closure
if to.Etype == TFUNC && from.IsPtrShaped() {
return v
}
// named <--> unnamed type or typed <--> untyped const
if from.Etype == to.Etype {
return v
}
// unsafe.Pointer <--> *T
if to.Etype == TUNSAFEPTR && from.IsPtr() || from.Etype == TUNSAFEPTR && to.IsPtr() {
return v
}
dowidth(from)
dowidth(to)
if from.Width != to.Width {
s.Fatalf("CONVNOP width mismatch %v (%d) -> %v (%d)\n", from, from.Width, to, to.Width)
return nil
}
if etypesign(from.Etype) != etypesign(to.Etype) {
s.Fatalf("CONVNOP sign mismatch %v (%s) -> %v (%s)\n", from, from.Etype, to, to.Etype)
return nil
}
if instrumenting {
// These appear to be fine, but they fail the
// integer constraint below, so okay them here.
// Sample non-integer conversion: map[string]string -> *uint8
return v
}
if etypesign(from.Etype) == 0 {
s.Fatalf("CONVNOP unrecognized non-integer %v -> %v\n", from, to)
return nil
}
// integer, same width, same sign
return v
case OCONV:
x := s.expr(n.Left)
ft := n.Left.Type // from type
tt := n.Type // to type
if ft.IsBoolean() && tt.IsKind(TUINT8) {
// Bool -> uint8 is generated internally when indexing into runtime.staticbyte.
return s.newValue1(ssa.OpCopy, n.Type, x)
}
if ft.IsInteger() && tt.IsInteger() {
var op ssa.Op
if tt.Size() == ft.Size() {
op = ssa.OpCopy
} else if tt.Size() < ft.Size() {
// truncation
switch 10*ft.Size() + tt.Size() {
case 21:
op = ssa.OpTrunc16to8
case 41:
op = ssa.OpTrunc32to8
case 42:
op = ssa.OpTrunc32to16
case 81:
op = ssa.OpTrunc64to8
case 82:
op = ssa.OpTrunc64to16
case 84:
op = ssa.OpTrunc64to32
default:
s.Fatalf("weird integer truncation %v -> %v", ft, tt)
}
} else if ft.IsSigned() {
// sign extension
switch 10*ft.Size() + tt.Size() {
case 12:
op = ssa.OpSignExt8to16
case 14:
op = ssa.OpSignExt8to32
case 18:
op = ssa.OpSignExt8to64
case 24:
op = ssa.OpSignExt16to32
case 28:
op = ssa.OpSignExt16to64
case 48:
op = ssa.OpSignExt32to64
default:
s.Fatalf("bad integer sign extension %v -> %v", ft, tt)
}
} else {
// zero extension
switch 10*ft.Size() + tt.Size() {
case 12:
op = ssa.OpZeroExt8to16
case 14:
op = ssa.OpZeroExt8to32
case 18:
op = ssa.OpZeroExt8to64
case 24:
op = ssa.OpZeroExt16to32
case 28:
op = ssa.OpZeroExt16to64
case 48:
op = ssa.OpZeroExt32to64
default:
s.Fatalf("weird integer sign extension %v -> %v", ft, tt)
}
}
return s.newValue1(op, n.Type, x)
}
if ft.IsFloat() || tt.IsFloat() {
conv, ok := fpConvOpToSSA[twoTypes{s.concreteEtype(ft), s.concreteEtype(tt)}]
if s.config.IntSize == 4 && Thearch.LinkArch.Name != "amd64p32" && Thearch.LinkArch.Family != sys.MIPS {
if conv1, ok1 := fpConvOpToSSA32[twoTypes{s.concreteEtype(ft), s.concreteEtype(tt)}]; ok1 {
conv = conv1
}
}
if Thearch.LinkArch.Name == "arm64" {
if conv1, ok1 := uint64fpConvOpToSSA[twoTypes{s.concreteEtype(ft), s.concreteEtype(tt)}]; ok1 {
conv = conv1
}
}
if Thearch.LinkArch.Family == sys.MIPS {
if ft.Size() == 4 && ft.IsInteger() && !ft.IsSigned() {
// tt is float32 or float64, and ft is also unsigned
if tt.Size() == 4 {
return s.uint32Tofloat32(n, x, ft, tt)
}
if tt.Size() == 8 {
return s.uint32Tofloat64(n, x, ft, tt)
}
} else if tt.Size() == 4 && tt.IsInteger() && !tt.IsSigned() {
// ft is float32 or float64, and tt is unsigned integer
if ft.Size() == 4 {
return s.float32ToUint32(n, x, ft, tt)
}
if ft.Size() == 8 {
return s.float64ToUint32(n, x, ft, tt)
}
}
}
if !ok {
s.Fatalf("weird float conversion %v -> %v", ft, tt)
}
op1, op2, it := conv.op1, conv.op2, conv.intermediateType
if op1 != ssa.OpInvalid && op2 != ssa.OpInvalid {
// normal case, not tripping over unsigned 64
if op1 == ssa.OpCopy {
if op2 == ssa.OpCopy {
return x
}
return s.newValue1(op2, n.Type, x)
}
if op2 == ssa.OpCopy {
return s.newValue1(op1, n.Type, x)
}
return s.newValue1(op2, n.Type, s.newValue1(op1, Types[it], x))
}
// Tricky 64-bit unsigned cases.
if ft.IsInteger() {
// tt is float32 or float64, and ft is also unsigned
if tt.Size() == 4 {
return s.uint64Tofloat32(n, x, ft, tt)
}
if tt.Size() == 8 {
return s.uint64Tofloat64(n, x, ft, tt)
}
s.Fatalf("weird unsigned integer to float conversion %v -> %v", ft, tt)
}
// ft is float32 or float64, and tt is unsigned integer
if ft.Size() == 4 {
return s.float32ToUint64(n, x, ft, tt)
}
if ft.Size() == 8 {
return s.float64ToUint64(n, x, ft, tt)
}
s.Fatalf("weird float to unsigned integer conversion %v -> %v", ft, tt)
return nil
}
if ft.IsComplex() && tt.IsComplex() {
var op ssa.Op
if ft.Size() == tt.Size() {
op = ssa.OpCopy
} else if ft.Size() == 8 && tt.Size() == 16 {
op = ssa.OpCvt32Fto64F
} else if ft.Size() == 16 && tt.Size() == 8 {
op = ssa.OpCvt64Fto32F
} else {
s.Fatalf("weird complex conversion %v -> %v", ft, tt)
}
ftp := floatForComplex(ft)
ttp := floatForComplex(tt)
return s.newValue2(ssa.OpComplexMake, tt,
s.newValue1(op, ttp, s.newValue1(ssa.OpComplexReal, ftp, x)),
s.newValue1(op, ttp, s.newValue1(ssa.OpComplexImag, ftp, x)))
}
s.Fatalf("unhandled OCONV %s -> %s", n.Left.Type.Etype, n.Type.Etype)
return nil
case ODOTTYPE:
res, _ := s.dottype(n, false)
return res
// binary ops
case OLT, OEQ, ONE, OLE, OGE, OGT:
a := s.expr(n.Left)
b := s.expr(n.Right)
if n.Left.Type.IsComplex() {
pt := floatForComplex(n.Left.Type)
op := s.ssaOp(OEQ, pt)
r := s.newValue2(op, Types[TBOOL], s.newValue1(ssa.OpComplexReal, pt, a), s.newValue1(ssa.OpComplexReal, pt, b))
i := s.newValue2(op, Types[TBOOL], s.newValue1(ssa.OpComplexImag, pt, a), s.newValue1(ssa.OpComplexImag, pt, b))
c := s.newValue2(ssa.OpAndB, Types[TBOOL], r, i)
switch n.Op {
case OEQ:
return c
case ONE:
return s.newValue1(ssa.OpNot, Types[TBOOL], c)
default:
s.Fatalf("ordered complex compare %v", n.Op)
}
}
return s.newValue2(s.ssaOp(n.Op, n.Left.Type), Types[TBOOL], a, b)
case OMUL:
a := s.expr(n.Left)
b := s.expr(n.Right)
if n.Type.IsComplex() {
mulop := ssa.OpMul64F
addop := ssa.OpAdd64F
subop := ssa.OpSub64F
pt := floatForComplex(n.Type) // Could be Float32 or Float64
wt := Types[TFLOAT64] // Compute in Float64 to minimize cancelation error
areal := s.newValue1(ssa.OpComplexReal, pt, a)
breal := s.newValue1(ssa.OpComplexReal, pt, b)
aimag := s.newValue1(ssa.OpComplexImag, pt, a)
bimag := s.newValue1(ssa.OpComplexImag, pt, b)
if pt != wt { // Widen for calculation
areal = s.newValue1(ssa.OpCvt32Fto64F, wt, areal)
breal = s.newValue1(ssa.OpCvt32Fto64F, wt, breal)
aimag = s.newValue1(ssa.OpCvt32Fto64F, wt, aimag)
bimag = s.newValue1(ssa.OpCvt32Fto64F, wt, bimag)
}
xreal := s.newValue2(subop, wt, s.newValue2(mulop, wt, areal, breal), s.newValue2(mulop, wt, aimag, bimag))
ximag := s.newValue2(addop, wt, s.newValue2(mulop, wt, areal, bimag), s.newValue2(mulop, wt, aimag, breal))
if pt != wt { // Narrow to store back
xreal = s.newValue1(ssa.OpCvt64Fto32F, pt, xreal)
ximag = s.newValue1(ssa.OpCvt64Fto32F, pt, ximag)
}
return s.newValue2(ssa.OpComplexMake, n.Type, xreal, ximag)
}
return s.newValue2(s.ssaOp(n.Op, n.Type), a.Type, a, b)
case ODIV:
a := s.expr(n.Left)
b := s.expr(n.Right)
if n.Type.IsComplex() {
// TODO this is not executed because the front-end substitutes a runtime call.
// That probably ought to change; with modest optimization the widen/narrow
// conversions could all be elided in larger expression trees.
mulop := ssa.OpMul64F
addop := ssa.OpAdd64F
subop := ssa.OpSub64F
divop := ssa.OpDiv64F
pt := floatForComplex(n.Type) // Could be Float32 or Float64
wt := Types[TFLOAT64] // Compute in Float64 to minimize cancelation error
areal := s.newValue1(ssa.OpComplexReal, pt, a)
breal := s.newValue1(ssa.OpComplexReal, pt, b)
aimag := s.newValue1(ssa.OpComplexImag, pt, a)
bimag := s.newValue1(ssa.OpComplexImag, pt, b)
if pt != wt { // Widen for calculation
areal = s.newValue1(ssa.OpCvt32Fto64F, wt, areal)
breal = s.newValue1(ssa.OpCvt32Fto64F, wt, breal)
aimag = s.newValue1(ssa.OpCvt32Fto64F, wt, aimag)
bimag = s.newValue1(ssa.OpCvt32Fto64F, wt, bimag)
}
denom := s.newValue2(addop, wt, s.newValue2(mulop, wt, breal, breal), s.newValue2(mulop, wt, bimag, bimag))
xreal := s.newValue2(addop, wt, s.newValue2(mulop, wt, areal, breal), s.newValue2(mulop, wt, aimag, bimag))
ximag := s.newValue2(subop, wt, s.newValue2(mulop, wt, aimag, breal), s.newValue2(mulop, wt, areal, bimag))
// TODO not sure if this is best done in wide precision or narrow
// Double-rounding might be an issue.
// Note that the pre-SSA implementation does the entire calculation
// in wide format, so wide is compatible.
xreal = s.newValue2(divop, wt, xreal, denom)
ximag = s.newValue2(divop, wt, ximag, denom)
if pt != wt { // Narrow to store back
xreal = s.newValue1(ssa.OpCvt64Fto32F, pt, xreal)
ximag = s.newValue1(ssa.OpCvt64Fto32F, pt, ximag)
}
return s.newValue2(ssa.OpComplexMake, n.Type, xreal, ximag)
}
if n.Type.IsFloat() {
return s.newValue2(s.ssaOp(n.Op, n.Type), a.Type, a, b)
}
return s.intDivide(n, a, b)
case OMOD:
a := s.expr(n.Left)
b := s.expr(n.Right)
return s.intDivide(n, a, b)
case OADD, OSUB:
a := s.expr(n.Left)
b := s.expr(n.Right)
if n.Type.IsComplex() {
pt := floatForComplex(n.Type)
op := s.ssaOp(n.Op, pt)
return s.newValue2(ssa.OpComplexMake, n.Type,
s.newValue2(op, pt, s.newValue1(ssa.OpComplexReal, pt, a), s.newValue1(ssa.OpComplexReal, pt, b)),
s.newValue2(op, pt, s.newValue1(ssa.OpComplexImag, pt, a), s.newValue1(ssa.OpComplexImag, pt, b)))
}
return s.newValue2(s.ssaOp(n.Op, n.Type), a.Type, a, b)
case OAND, OOR, OHMUL, OXOR:
a := s.expr(n.Left)
b := s.expr(n.Right)
return s.newValue2(s.ssaOp(n.Op, n.Type), a.Type, a, b)
case OLSH, ORSH:
a := s.expr(n.Left)
b := s.expr(n.Right)
return s.newValue2(s.ssaShiftOp(n.Op, n.Type, n.Right.Type), a.Type, a, b)
case OANDAND, OOROR:
// To implement OANDAND (and OOROR), we introduce a
// new temporary variable to hold the result. The
// variable is associated with the OANDAND node in the
// s.vars table (normally variables are only
// associated with ONAME nodes). We convert
// A && B
// to
// var = A
// if var {
// var = B
// }
// Using var in the subsequent block introduces the
// necessary phi variable.
el := s.expr(n.Left)
s.vars[n] = el
b := s.endBlock()
b.Kind = ssa.BlockIf
b.SetControl(el)
// In theory, we should set b.Likely here based on context.
// However, gc only gives us likeliness hints
// in a single place, for plain OIF statements,
// and passing around context is finnicky, so don't bother for now.
bRight := s.f.NewBlock(ssa.BlockPlain)
bResult := s.f.NewBlock(ssa.BlockPlain)
if n.Op == OANDAND {
b.AddEdgeTo(bRight)
b.AddEdgeTo(bResult)
} else if n.Op == OOROR {
b.AddEdgeTo(bResult)
b.AddEdgeTo(bRight)
}
s.startBlock(bRight)
er := s.expr(n.Right)
s.vars[n] = er
b = s.endBlock()
b.AddEdgeTo(bResult)
s.startBlock(bResult)
return s.variable(n, Types[TBOOL])
case OCOMPLEX:
r := s.expr(n.Left)
i := s.expr(n.Right)
return s.newValue2(ssa.OpComplexMake, n.Type, r, i)
// unary ops
case OMINUS:
a := s.expr(n.Left)
if n.Type.IsComplex() {
tp := floatForComplex(n.Type)
negop := s.ssaOp(n.Op, tp)
return s.newValue2(ssa.OpComplexMake, n.Type,
s.newValue1(negop, tp, s.newValue1(ssa.OpComplexReal, tp, a)),
s.newValue1(negop, tp, s.newValue1(ssa.OpComplexImag, tp, a)))
}
return s.newValue1(s.ssaOp(n.Op, n.Type), a.Type, a)
case ONOT, OCOM:
a := s.expr(n.Left)
return s.newValue1(s.ssaOp(n.Op, n.Type), a.Type, a)
case OIMAG, OREAL:
a := s.expr(n.Left)
return s.newValue1(s.ssaOp(n.Op, n.Left.Type), n.Type, a)
case OPLUS:
return s.expr(n.Left)
case OADDR:
a, _ := s.addr(n.Left, n.Bounded)
// Note we know the volatile result is false because you can't write &f() in Go.
return a
case OINDREGSP:
addr := s.entryNewValue1I(ssa.OpOffPtr, ptrto(n.Type), n.Xoffset, s.sp)
return s.newValue2(ssa.OpLoad, n.Type, addr, s.mem())
case OIND:
p := s.exprPtr(n.Left, false, n.Pos)
return s.newValue2(ssa.OpLoad, n.Type, p, s.mem())
case ODOT:
t := n.Left.Type
if canSSAType(t) {
v := s.expr(n.Left)
return s.newValue1I(ssa.OpStructSelect, n.Type, int64(fieldIdx(n)), v)
}
if n.Left.Op == OSTRUCTLIT {
// All literals with nonzero fields have already been
// rewritten during walk. Any that remain are just T{}
// or equivalents. Use the zero value.
if !iszero(n.Left) {
Fatalf("literal with nonzero value in SSA: %v", n.Left)
}
return s.zeroVal(n.Type)
}
p, _ := s.addr(n, false)
return s.newValue2(ssa.OpLoad, n.Type, p, s.mem())
case ODOTPTR:
p := s.exprPtr(n.Left, false, n.Pos)
p = s.newValue1I(ssa.OpOffPtr, p.Type, n.Xoffset, p)
return s.newValue2(ssa.OpLoad, n.Type, p, s.mem())
case OINDEX:
switch {
case n.Left.Type.IsString():
if n.Bounded && Isconst(n.Left, CTSTR) && Isconst(n.Right, CTINT) {
// Replace "abc"[1] with 'b'.
// Delayed until now because "abc"[1] is not an ideal constant.
// See test/fixedbugs/issue11370.go.
return s.newValue0I(ssa.OpConst8, Types[TUINT8], int64(int8(n.Left.Val().U.(string)[n.Right.Int64()])))
}
a := s.expr(n.Left)
i := s.expr(n.Right)
i = s.extendIndex(i, panicindex)
if !n.Bounded {
len := s.newValue1(ssa.OpStringLen, Types[TINT], a)
s.boundsCheck(i, len)
}
ptrtyp := ptrto(Types[TUINT8])
ptr := s.newValue1(ssa.OpStringPtr, ptrtyp, a)
if Isconst(n.Right, CTINT) {
ptr = s.newValue1I(ssa.OpOffPtr, ptrtyp, n.Right.Int64(), ptr)
} else {
ptr = s.newValue2(ssa.OpAddPtr, ptrtyp, ptr, i)
}
return s.newValue2(ssa.OpLoad, Types[TUINT8], ptr, s.mem())
case n.Left.Type.IsSlice():
p, _ := s.addr(n, false)
return s.newValue2(ssa.OpLoad, n.Left.Type.Elem(), p, s.mem())
case n.Left.Type.IsArray():
if bound := n.Left.Type.NumElem(); bound <= 1 {
// SSA can handle arrays of length at most 1.
a := s.expr(n.Left)
i := s.expr(n.Right)
if bound == 0 {
// Bounds check will never succeed. Might as well
// use constants for the bounds check.
z := s.constInt(Types[TINT], 0)
s.boundsCheck(z, z)
// The return value won't be live, return junk.
return s.newValue0(ssa.OpUnknown, n.Type)
}
i = s.extendIndex(i, panicindex)
s.boundsCheck(i, s.constInt(Types[TINT], bound))
return s.newValue1I(ssa.OpArraySelect, n.Type, 0, a)
}
p, _ := s.addr(n, false)
return s.newValue2(ssa.OpLoad, n.Left.Type.Elem(), p, s.mem())
default:
s.Fatalf("bad type for index %v", n.Left.Type)
return nil
}
case OLEN, OCAP:
switch {
case n.Left.Type.IsSlice():
op := ssa.OpSliceLen
if n.Op == OCAP {
op = ssa.OpSliceCap
}
return s.newValue1(op, Types[TINT], s.expr(n.Left))
case n.Left.Type.IsString(): // string; not reachable for OCAP
return s.newValue1(ssa.OpStringLen, Types[TINT], s.expr(n.Left))
case n.Left.Type.IsMap(), n.Left.Type.IsChan():
return s.referenceTypeBuiltin(n, s.expr(n.Left))
default: // array
return s.constInt(Types[TINT], n.Left.Type.NumElem())
}
case OSPTR:
a := s.expr(n.Left)
if n.Left.Type.IsSlice() {
return s.newValue1(ssa.OpSlicePtr, n.Type, a)
} else {
return s.newValue1(ssa.OpStringPtr, n.Type, a)
}
case OITAB:
a := s.expr(n.Left)
return s.newValue1(ssa.OpITab, n.Type, a)
case OIDATA:
a := s.expr(n.Left)
return s.newValue1(ssa.OpIData, n.Type, a)
case OEFACE:
tab := s.expr(n.Left)
data := s.expr(n.Right)
return s.newValue2(ssa.OpIMake, n.Type, tab, data)
case OSLICE, OSLICEARR, OSLICE3, OSLICE3ARR:
v := s.expr(n.Left)
var i, j, k *ssa.Value
low, high, max := n.SliceBounds()
if low != nil {
i = s.extendIndex(s.expr(low), panicslice)
}
if high != nil {
j = s.extendIndex(s.expr(high), panicslice)
}
if max != nil {
k = s.extendIndex(s.expr(max), panicslice)
}
p, l, c := s.slice(n.Left.Type, v, i, j, k)
return s.newValue3(ssa.OpSliceMake, n.Type, p, l, c)
case OSLICESTR:
v := s.expr(n.Left)
var i, j *ssa.Value
low, high, _ := n.SliceBounds()
if low != nil {
i = s.extendIndex(s.expr(low), panicslice)
}
if high != nil {
j = s.extendIndex(s.expr(high), panicslice)
}
p, l, _ := s.slice(n.Left.Type, v, i, j, nil)
return s.newValue2(ssa.OpStringMake, n.Type, p, l)
case OCALLFUNC:
if isIntrinsicCall(n) {
return s.intrinsicCall(n)
}
fallthrough
case OCALLINTER, OCALLMETH:
a := s.call(n, callNormal)
return s.newValue2(ssa.OpLoad, n.Type, a, s.mem())
case OGETG:
return s.newValue1(ssa.OpGetG, n.Type, s.mem())
case OAPPEND:
return s.append(n, false)
case OSTRUCTLIT, OARRAYLIT:
// All literals with nonzero fields have already been
// rewritten during walk. Any that remain are just T{}
// or equivalents. Use the zero value.
if !iszero(n) {
Fatalf("literal with nonzero value in SSA: %v", n)
}
return s.zeroVal(n.Type)
default:
s.Fatalf("unhandled expr %v", n.Op)
return nil
}
}
// append converts an OAPPEND node to SSA.
// If inplace is false, it converts the OAPPEND expression n to an ssa.Value,
// adds it to s, and returns the Value.
// If inplace is true, it writes the result of the OAPPEND expression n
// back to the slice being appended to, and returns nil.
// inplace MUST be set to false if the slice can be SSA'd.
func (s *state) append(n *Node, inplace bool) *ssa.Value {
// If inplace is false, process as expression "append(s, e1, e2, e3)":
//
// ptr, len, cap := s
// newlen := len + 3
// if newlen > cap {
// ptr, len, cap = growslice(s, newlen)
// newlen = len + 3 // recalculate to avoid a spill
// }
// // with write barriers, if needed:
// *(ptr+len) = e1
// *(ptr+len+1) = e2
// *(ptr+len+2) = e3
// return makeslice(ptr, newlen, cap)
//
//
// If inplace is true, process as statement "s = append(s, e1, e2, e3)":
//
// a := &s
// ptr, len, cap := s
// newlen := len + 3
// if newlen > cap {
// newptr, len, newcap = growslice(ptr, len, cap, newlen)
// vardef(a) // if necessary, advise liveness we are writing a new a
// *a.cap = newcap // write before ptr to avoid a spill
// *a.ptr = newptr // with write barrier
// }
// newlen = len + 3 // recalculate to avoid a spill
// *a.len = newlen
// // with write barriers, if needed:
// *(ptr+len) = e1
// *(ptr+len+1) = e2
// *(ptr+len+2) = e3
et := n.Type.Elem()
pt := ptrto(et)
// Evaluate slice
sn := n.List.First() // the slice node is the first in the list
var slice, addr *ssa.Value
if inplace {
addr, _ = s.addr(sn, false)
slice = s.newValue2(ssa.OpLoad, n.Type, addr, s.mem())
} else {
slice = s.expr(sn)
}
// Allocate new blocks
grow := s.f.NewBlock(ssa.BlockPlain)
assign := s.f.NewBlock(ssa.BlockPlain)
// Decide if we need to grow
nargs := int64(n.List.Len() - 1)
p := s.newValue1(ssa.OpSlicePtr, pt, slice)
l := s.newValue1(ssa.OpSliceLen, Types[TINT], slice)
c := s.newValue1(ssa.OpSliceCap, Types[TINT], slice)
nl := s.newValue2(s.ssaOp(OADD, Types[TINT]), Types[TINT], l, s.constInt(Types[TINT], nargs))
cmp := s.newValue2(s.ssaOp(OGT, Types[TINT]), Types[TBOOL], nl, c)
s.vars[&ptrVar] = p
if !inplace {
s.vars[&newlenVar] = nl
s.vars[&capVar] = c
} else {
s.vars[&lenVar] = l
}
b := s.endBlock()
b.Kind = ssa.BlockIf
b.Likely = ssa.BranchUnlikely
b.SetControl(cmp)
b.AddEdgeTo(grow)
b.AddEdgeTo(assign)
// Call growslice
s.startBlock(grow)
taddr := s.newValue1A(ssa.OpAddr, Types[TUINTPTR], &ssa.ExternSymbol{Typ: Types[TUINTPTR], Sym: Linksym(typenamesym(n.Type.Elem()))}, s.sb)
r := s.rtcall(growslice, true, []*Type{pt, Types[TINT], Types[TINT]}, taddr, p, l, c, nl)
if inplace {
if sn.Op == ONAME {
// Tell liveness we're about to build a new slice
s.vars[&memVar] = s.newValue1A(ssa.OpVarDef, ssa.TypeMem, sn, s.mem())
}
capaddr := s.newValue1I(ssa.OpOffPtr, pt, int64(array_cap), addr)
s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, s.config.IntSize, capaddr, r[2], s.mem())
if ssa.IsStackAddr(addr) {
s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, pt.Size(), addr, r[0], s.mem())
} else {
s.insertWBstore(pt, addr, r[0], 0)
}
// load the value we just stored to avoid having to spill it
s.vars[&ptrVar] = s.newValue2(ssa.OpLoad, pt, addr, s.mem())
s.vars[&lenVar] = r[1] // avoid a spill in the fast path
} else {
s.vars[&ptrVar] = r[0]
s.vars[&newlenVar] = s.newValue2(s.ssaOp(OADD, Types[TINT]), Types[TINT], r[1], s.constInt(Types[TINT], nargs))
s.vars[&capVar] = r[2]
}
b = s.endBlock()
b.AddEdgeTo(assign)
// assign new elements to slots
s.startBlock(assign)
if inplace {
l = s.variable(&lenVar, Types[TINT]) // generates phi for len
nl = s.newValue2(s.ssaOp(OADD, Types[TINT]), Types[TINT], l, s.constInt(Types[TINT], nargs))
lenaddr := s.newValue1I(ssa.OpOffPtr, pt, int64(array_nel), addr)
s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, s.config.IntSize, lenaddr, nl, s.mem())
}
// Evaluate args
type argRec struct {
// if store is true, we're appending the value v. If false, we're appending the
// value at *v. If store==false, isVolatile reports whether the source
// is in the outargs section of the stack frame.
v *ssa.Value
store bool
isVolatile bool
}
args := make([]argRec, 0, nargs)
for _, n := range n.List.Slice()[1:] {
if canSSAType(n.Type) {
args = append(args, argRec{v: s.expr(n), store: true})
} else {
v, isVolatile := s.addr(n, false)
args = append(args, argRec{v: v, isVolatile: isVolatile})
}
}
p = s.variable(&ptrVar, pt) // generates phi for ptr
if !inplace {
nl = s.variable(&newlenVar, Types[TINT]) // generates phi for nl
c = s.variable(&capVar, Types[TINT]) // generates phi for cap
}
p2 := s.newValue2(ssa.OpPtrIndex, pt, p, l)
// TODO: just one write barrier call for all of these writes?
// TODO: maybe just one writeBarrier.enabled check?
for i, arg := range args {
addr := s.newValue2(ssa.OpPtrIndex, pt, p2, s.constInt(Types[TINT], int64(i)))
if arg.store {
if haspointers(et) {
s.insertWBstore(et, addr, arg.v, 0)
} else {
s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, et.Size(), addr, arg.v, s.mem())
}
} else {
if haspointers(et) {
s.insertWBmove(et, addr, arg.v, arg.isVolatile)
} else {
s.vars[&memVar] = s.newValue3I(ssa.OpMove, ssa.TypeMem, sizeAlignAuxInt(et), addr, arg.v, s.mem())
}
}
}
delete(s.vars, &ptrVar)
if inplace {
delete(s.vars, &lenVar)
return nil
}
delete(s.vars, &newlenVar)
delete(s.vars, &capVar)
// make result
return s.newValue3(ssa.OpSliceMake, n.Type, p, nl, c)
}
// condBranch evaluates the boolean expression cond and branches to yes
// if cond is true and no if cond is false.
// This function is intended to handle && and || better than just calling
// s.expr(cond) and branching on the result.
func (s *state) condBranch(cond *Node, yes, no *ssa.Block, likely int8) {
if cond.Op == OANDAND {
mid := s.f.NewBlock(ssa.BlockPlain)
s.stmtList(cond.Ninit)
s.condBranch(cond.Left, mid, no, max8(likely, 0))
s.startBlock(mid)
s.condBranch(cond.Right, yes, no, likely)
return
// Note: if likely==1, then both recursive calls pass 1.
// If likely==-1, then we don't have enough information to decide
// whether the first branch is likely or not. So we pass 0 for
// the likeliness of the first branch.
// TODO: have the frontend give us branch prediction hints for
// OANDAND and OOROR nodes (if it ever has such info).
}
if cond.Op == OOROR {
mid := s.f.NewBlock(ssa.BlockPlain)
s.stmtList(cond.Ninit)
s.condBranch(cond.Left, yes, mid, min8(likely, 0))
s.startBlock(mid)
s.condBranch(cond.Right, yes, no, likely)
return
// Note: if likely==-1, then both recursive calls pass -1.
// If likely==1, then we don't have enough info to decide
// the likelihood of the first branch.
}
if cond.Op == ONOT {
s.stmtList(cond.Ninit)
s.condBranch(cond.Left, no, yes, -likely)
return
}
c := s.expr(cond)
b := s.endBlock()
b.Kind = ssa.BlockIf
b.SetControl(c)
b.Likely = ssa.BranchPrediction(likely) // gc and ssa both use -1/0/+1 for likeliness
b.AddEdgeTo(yes)
b.AddEdgeTo(no)
}
type skipMask uint8
const (
skipPtr skipMask = 1 << iota
skipLen
skipCap
)
// assign does left = right.
// Right has already been evaluated to ssa, left has not.
// If deref is true, then we do left = *right instead (and right has already been nil-checked).
// If deref is true and right == nil, just do left = 0.
// If deref is true, rightIsVolatile reports whether right points to volatile (clobbered by a call) storage.
// Include a write barrier if wb is true.
// skip indicates assignments (at the top level) that can be avoided.
func (s *state) assign(left *Node, right *ssa.Value, wb, deref bool, skip skipMask, rightIsVolatile bool) {
if left.Op == ONAME && isblank(left) {
return
}
t := left.Type
dowidth(t)
if s.canSSA(left) {
if deref {
s.Fatalf("can SSA LHS %v but not RHS %s", left, right)
}
if left.Op == ODOT {
// We're assigning to a field of an ssa-able value.
// We need to build a new structure with the new value for the
// field we're assigning and the old values for the other fields.
// For instance:
// type T struct {a, b, c int}
// var T x
// x.b = 5
// For the x.b = 5 assignment we want to generate x = T{x.a, 5, x.c}
// Grab information about the structure type.
t := left.Left.Type
nf := t.NumFields()
idx := fieldIdx(left)
// Grab old value of structure.
old := s.expr(left.Left)
// Make new structure.
new := s.newValue0(ssa.StructMakeOp(t.NumFields()), t)
// Add fields as args.
for i := 0; i < nf; i++ {
if i == idx {
new.AddArg(right)
} else {
new.AddArg(s.newValue1I(ssa.OpStructSelect, t.FieldType(i), int64(i), old))
}
}
// Recursively assign the new value we've made to the base of the dot op.
s.assign(left.Left, new, false, false, 0, rightIsVolatile)
// TODO: do we need to update named values here?
return
}
if left.Op == OINDEX && left.Left.Type.IsArray() {
// We're assigning to an element of an ssa-able array.
// a[i] = v
t := left.Left.Type
n := t.NumElem()
i := s.expr(left.Right) // index
if n == 0 {
// The bounds check must fail. Might as well
// ignore the actual index and just use zeros.
z := s.constInt(Types[TINT], 0)
s.boundsCheck(z, z)
return
}
if n != 1 {
s.Fatalf("assigning to non-1-length array")
}
// Rewrite to a = [1]{v}
i = s.extendIndex(i, panicindex)
s.boundsCheck(i, s.constInt(Types[TINT], 1))
v := s.newValue1(ssa.OpArrayMake1, t, right)
s.assign(left.Left, v, false, false, 0, rightIsVolatile)
return
}
// Update variable assignment.
s.vars[left] = right
s.addNamedValue(left, right)
return
}
// Left is not ssa-able. Compute its address.
addr, _ := s.addr(left, false)
if left.Op == ONAME && skip == 0 {
s.vars[&memVar] = s.newValue1A(ssa.OpVarDef, ssa.TypeMem, left, s.mem())
}
if deref {
// Treat as a mem->mem move.
if wb && !ssa.IsStackAddr(addr) {
s.insertWBmove(t, addr, right, rightIsVolatile)
return
}
if right == nil {
s.vars[&memVar] = s.newValue2I(ssa.OpZero, ssa.TypeMem, sizeAlignAuxInt(t), addr, s.mem())
return
}
s.vars[&memVar] = s.newValue3I(ssa.OpMove, ssa.TypeMem, sizeAlignAuxInt(t), addr, right, s.mem())
return
}
// Treat as a store.
if wb && !ssa.IsStackAddr(addr) {
if skip&skipPtr != 0 {
// Special case: if we don't write back the pointers, don't bother
// doing the write barrier check.
s.storeTypeScalars(t, addr, right, skip)
return
}
s.insertWBstore(t, addr, right, skip)
return
}
if skip != 0 {
if skip&skipPtr == 0 {
s.storeTypePtrs(t, addr, right)
}
s.storeTypeScalars(t, addr, right, skip)
return
}
s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, t.Size(), addr, right, s.mem())
}
// zeroVal returns the zero value for type t.
func (s *state) zeroVal(t *Type) *ssa.Value {
switch {
case t.IsInteger():
switch t.Size() {
case 1:
return s.constInt8(t, 0)
case 2:
return s.constInt16(t, 0)
case 4:
return s.constInt32(t, 0)
case 8:
return s.constInt64(t, 0)
default:
s.Fatalf("bad sized integer type %v", t)
}
case t.IsFloat():
switch t.Size() {
case 4:
return s.constFloat32(t, 0)
case 8:
return s.constFloat64(t, 0)
default:
s.Fatalf("bad sized float type %v", t)
}
case t.IsComplex():
switch t.Size() {
case 8:
z := s.constFloat32(Types[TFLOAT32], 0)
return s.entryNewValue2(ssa.OpComplexMake, t, z, z)
case 16:
z := s.constFloat64(Types[TFLOAT64], 0)
return s.entryNewValue2(ssa.OpComplexMake, t, z, z)
default:
s.Fatalf("bad sized complex type %v", t)
}
case t.IsString():
return s.constEmptyString(t)
case t.IsPtrShaped():
return s.constNil(t)
case t.IsBoolean():
return s.constBool(false)
case t.IsInterface():
return s.constInterface(t)
case t.IsSlice():
return s.constSlice(t)
case t.IsStruct():
n := t.NumFields()
v := s.entryNewValue0(ssa.StructMakeOp(t.NumFields()), t)
for i := 0; i < n; i++ {
v.AddArg(s.zeroVal(t.FieldType(i).(*Type)))
}
return v
case t.IsArray():
switch t.NumElem() {
case 0:
return s.entryNewValue0(ssa.OpArrayMake0, t)
case 1:
return s.entryNewValue1(ssa.OpArrayMake1, t, s.zeroVal(t.Elem()))
}
}
s.Fatalf("zero for type %v not implemented", t)
return nil
}
type callKind int8
const (
callNormal callKind = iota
callDefer
callGo
)
// TODO: make this a field of a configuration object instead of a global.
var intrinsics *intrinsicInfo
type intrinsicInfo struct {
std map[intrinsicKey]intrinsicBuilder
intSized map[sizedIntrinsicKey]intrinsicBuilder
ptrSized map[sizedIntrinsicKey]intrinsicBuilder
}
// An intrinsicBuilder converts a call node n into an ssa value that
// implements that call as an intrinsic. args is a list of arguments to the func.
type intrinsicBuilder func(s *state, n *Node, args []*ssa.Value) *ssa.Value
type intrinsicKey struct {
pkg string
fn string
}
type sizedIntrinsicKey struct {
pkg string
fn string
size int
}
// disableForInstrumenting returns nil when instrumenting, fn otherwise
func disableForInstrumenting(fn intrinsicBuilder) intrinsicBuilder {
if instrumenting {
return nil
}
return fn
}
// enableOnArch returns fn on given archs, nil otherwise
func enableOnArch(fn intrinsicBuilder, archs ...sys.ArchFamily) intrinsicBuilder {
if Thearch.LinkArch.InFamily(archs...) {
return fn
}
return nil
}
func intrinsicInit() {
i := &intrinsicInfo{}
intrinsics = i
// initial set of intrinsics.
i.std = map[intrinsicKey]intrinsicBuilder{
/******** runtime ********/
intrinsicKey{"runtime", "slicebytetostringtmp"}: disableForInstrumenting(func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
// Compiler frontend optimizations emit OARRAYBYTESTRTMP nodes
// for the backend instead of slicebytetostringtmp calls
// when not instrumenting.
slice := args[0]
ptr := s.newValue1(ssa.OpSlicePtr, ptrto(Types[TUINT8]), slice)
len := s.newValue1(ssa.OpSliceLen, Types[TINT], slice)
return s.newValue2(ssa.OpStringMake, n.Type, ptr, len)
}),
intrinsicKey{"runtime", "KeepAlive"}: func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
data := s.newValue1(ssa.OpIData, ptrto(Types[TUINT8]), args[0])
s.vars[&memVar] = s.newValue2(ssa.OpKeepAlive, ssa.TypeMem, data, s.mem())
return nil
},
/******** runtime/internal/sys ********/
intrinsicKey{"runtime/internal/sys", "Ctz32"}: enableOnArch(func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
return s.newValue1(ssa.OpCtz32, Types[TUINT32], args[0])
}, sys.AMD64, sys.ARM64, sys.ARM, sys.S390X, sys.MIPS),
intrinsicKey{"runtime/internal/sys", "Ctz64"}: enableOnArch(func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
return s.newValue1(ssa.OpCtz64, Types[TUINT64], args[0])
}, sys.AMD64, sys.ARM64, sys.ARM, sys.S390X, sys.MIPS),
intrinsicKey{"runtime/internal/sys", "Bswap32"}: enableOnArch(func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
return s.newValue1(ssa.OpBswap32, Types[TUINT32], args[0])
}, sys.AMD64, sys.ARM64, sys.ARM, sys.S390X),
intrinsicKey{"runtime/internal/sys", "Bswap64"}: enableOnArch(func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
return s.newValue1(ssa.OpBswap64, Types[TUINT64], args[0])
}, sys.AMD64, sys.ARM64, sys.ARM, sys.S390X),
/******** runtime/internal/atomic ********/
intrinsicKey{"runtime/internal/atomic", "Load"}: enableOnArch(func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
v := s.newValue2(ssa.OpAtomicLoad32, ssa.MakeTuple(Types[TUINT32], ssa.TypeMem), args[0], s.mem())
s.vars[&memVar] = s.newValue1(ssa.OpSelect1, ssa.TypeMem, v)
return s.newValue1(ssa.OpSelect0, Types[TUINT32], v)
}, sys.AMD64, sys.ARM64, sys.S390X, sys.MIPS),
intrinsicKey{"runtime/internal/atomic", "Load64"}: enableOnArch(func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
v := s.newValue2(ssa.OpAtomicLoad64, ssa.MakeTuple(Types[TUINT64], ssa.TypeMem), args[0], s.mem())
s.vars[&memVar] = s.newValue1(ssa.OpSelect1, ssa.TypeMem, v)
return s.newValue1(ssa.OpSelect0, Types[TUINT64], v)
}, sys.AMD64, sys.ARM64, sys.S390X),
intrinsicKey{"runtime/internal/atomic", "Loadp"}: enableOnArch(func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
v := s.newValue2(ssa.OpAtomicLoadPtr, ssa.MakeTuple(ptrto(Types[TUINT8]), ssa.TypeMem), args[0], s.mem())
s.vars[&memVar] = s.newValue1(ssa.OpSelect1, ssa.TypeMem, v)
return s.newValue1(ssa.OpSelect0, ptrto(Types[TUINT8]), v)
}, sys.AMD64, sys.ARM64, sys.S390X, sys.MIPS),
intrinsicKey{"runtime/internal/atomic", "Store"}: enableOnArch(func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
s.vars[&memVar] = s.newValue3(ssa.OpAtomicStore32, ssa.TypeMem, args[0], args[1], s.mem())
return nil
}, sys.AMD64, sys.ARM64, sys.S390X, sys.MIPS),
intrinsicKey{"runtime/internal/atomic", "Store64"}: enableOnArch(func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
s.vars[&memVar] = s.newValue3(ssa.OpAtomicStore64, ssa.TypeMem, args[0], args[1], s.mem())
return nil
}, sys.AMD64, sys.ARM64, sys.S390X),
intrinsicKey{"runtime/internal/atomic", "StorepNoWB"}: enableOnArch(func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
s.vars[&memVar] = s.newValue3(ssa.OpAtomicStorePtrNoWB, ssa.TypeMem, args[0], args[1], s.mem())
return nil
}, sys.AMD64, sys.ARM64, sys.S390X, sys.MIPS),
intrinsicKey{"runtime/internal/atomic", "Xchg"}: enableOnArch(func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
v := s.newValue3(ssa.OpAtomicExchange32, ssa.MakeTuple(Types[TUINT32], ssa.TypeMem), args[0], args[1], s.mem())
s.vars[&memVar] = s.newValue1(ssa.OpSelect1, ssa.TypeMem, v)
return s.newValue1(ssa.OpSelect0, Types[TUINT32], v)
}, sys.AMD64, sys.ARM64, sys.S390X, sys.MIPS),
intrinsicKey{"runtime/internal/atomic", "Xchg64"}: enableOnArch(func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
v := s.newValue3(ssa.OpAtomicExchange64, ssa.MakeTuple(Types[TUINT64], ssa.TypeMem), args[0], args[1], s.mem())
s.vars[&memVar] = s.newValue1(ssa.OpSelect1, ssa.TypeMem, v)
return s.newValue1(ssa.OpSelect0, Types[TUINT64], v)
}, sys.AMD64, sys.ARM64, sys.S390X),
intrinsicKey{"runtime/internal/atomic", "Xadd"}: enableOnArch(func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
v := s.newValue3(ssa.OpAtomicAdd32, ssa.MakeTuple(Types[TUINT32], ssa.TypeMem), args[0], args[1], s.mem())
s.vars[&memVar] = s.newValue1(ssa.OpSelect1, ssa.TypeMem, v)
return s.newValue1(ssa.OpSelect0, Types[TUINT32], v)
}, sys.AMD64, sys.ARM64, sys.S390X, sys.MIPS),
intrinsicKey{"runtime/internal/atomic", "Xadd64"}: enableOnArch(func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
v := s.newValue3(ssa.OpAtomicAdd64, ssa.MakeTuple(Types[TUINT64], ssa.TypeMem), args[0], args[1], s.mem())
s.vars[&memVar] = s.newValue1(ssa.OpSelect1, ssa.TypeMem, v)
return s.newValue1(ssa.OpSelect0, Types[TUINT64], v)
}, sys.AMD64, sys.ARM64, sys.S390X),
intrinsicKey{"runtime/internal/atomic", "Cas"}: enableOnArch(func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
v := s.newValue4(ssa.OpAtomicCompareAndSwap32, ssa.MakeTuple(Types[TBOOL], ssa.TypeMem), args[0], args[1], args[2], s.mem())
s.vars[&memVar] = s.newValue1(ssa.OpSelect1, ssa.TypeMem, v)
return s.newValue1(ssa.OpSelect0, Types[TBOOL], v)
}, sys.AMD64, sys.ARM64, sys.S390X, sys.MIPS),
intrinsicKey{"runtime/internal/atomic", "Cas64"}: enableOnArch(func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
v := s.newValue4(ssa.OpAtomicCompareAndSwap64, ssa.MakeTuple(Types[TBOOL], ssa.TypeMem), args[0], args[1], args[2], s.mem())
s.vars[&memVar] = s.newValue1(ssa.OpSelect1, ssa.TypeMem, v)
return s.newValue1(ssa.OpSelect0, Types[TBOOL], v)
}, sys.AMD64, sys.ARM64, sys.S390X),
intrinsicKey{"runtime/internal/atomic", "And8"}: enableOnArch(func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
s.vars[&memVar] = s.newValue3(ssa.OpAtomicAnd8, ssa.TypeMem, args[0], args[1], s.mem())
return nil
}, sys.AMD64, sys.ARM64, sys.MIPS),
intrinsicKey{"runtime/internal/atomic", "Or8"}: enableOnArch(func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
s.vars[&memVar] = s.newValue3(ssa.OpAtomicOr8, ssa.TypeMem, args[0], args[1], s.mem())
return nil
}, sys.AMD64, sys.ARM64, sys.MIPS),
/******** math ********/
intrinsicKey{"math", "Sqrt"}: enableOnArch(func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
return s.newValue1(ssa.OpSqrt, Types[TFLOAT64], args[0])
}, sys.AMD64, sys.ARM, sys.ARM64, sys.MIPS, sys.PPC64, sys.S390X),
}
// aliases internal to runtime/internal/atomic
i.std[intrinsicKey{"runtime/internal/atomic", "Loadint64"}] =
i.std[intrinsicKey{"runtime/internal/atomic", "Load64"}]
i.std[intrinsicKey{"runtime/internal/atomic", "Xaddint64"}] =
i.std[intrinsicKey{"runtime/internal/atomic", "Xadd64"}]
// intrinsics which vary depending on the size of int/ptr.
i.intSized = map[sizedIntrinsicKey]intrinsicBuilder{
sizedIntrinsicKey{"runtime/internal/atomic", "Loaduint", 4}: i.std[intrinsicKey{"runtime/internal/atomic", "Load"}],
sizedIntrinsicKey{"runtime/internal/atomic", "Loaduint", 8}: i.std[intrinsicKey{"runtime/internal/atomic", "Load64"}],
}
i.ptrSized = map[sizedIntrinsicKey]intrinsicBuilder{
sizedIntrinsicKey{"runtime/internal/atomic", "Loaduintptr", 4}: i.std[intrinsicKey{"runtime/internal/atomic", "Load"}],
sizedIntrinsicKey{"runtime/internal/atomic", "Loaduintptr", 8}: i.std[intrinsicKey{"runtime/internal/atomic", "Load64"}],
sizedIntrinsicKey{"runtime/internal/atomic", "Storeuintptr", 4}: i.std[intrinsicKey{"runtime/internal/atomic", "Store"}],
sizedIntrinsicKey{"runtime/internal/atomic", "Storeuintptr", 8}: i.std[intrinsicKey{"runtime/internal/atomic", "Store64"}],
sizedIntrinsicKey{"runtime/internal/atomic", "Xchguintptr", 4}: i.std[intrinsicKey{"runtime/internal/atomic", "Xchg"}],
sizedIntrinsicKey{"runtime/internal/atomic", "Xchguintptr", 8}: i.std[intrinsicKey{"runtime/internal/atomic", "Xchg64"}],
sizedIntrinsicKey{"runtime/internal/atomic", "Xadduintptr", 4}: i.std[intrinsicKey{"runtime/internal/atomic", "Xadd"}],
sizedIntrinsicKey{"runtime/internal/atomic", "Xadduintptr", 8}: i.std[intrinsicKey{"runtime/internal/atomic", "Xadd64"}],
sizedIntrinsicKey{"runtime/internal/atomic", "Casuintptr", 4}: i.std[intrinsicKey{"runtime/internal/atomic", "Cas"}],
sizedIntrinsicKey{"runtime/internal/atomic", "Casuintptr", 8}: i.std[intrinsicKey{"runtime/internal/atomic", "Cas64"}],
sizedIntrinsicKey{"runtime/internal/atomic", "Casp1", 4}: i.std[intrinsicKey{"runtime/internal/atomic", "Cas"}],
sizedIntrinsicKey{"runtime/internal/atomic", "Casp1", 8}: i.std[intrinsicKey{"runtime/internal/atomic", "Cas64"}],
}
/******** sync/atomic ********/
if flag_race {
// The race detector needs to be able to intercept these calls.
// We can't intrinsify them.
return
}
// these are all aliases to runtime/internal/atomic implementations.
i.std[intrinsicKey{"sync/atomic", "LoadInt32"}] =
i.std[intrinsicKey{"runtime/internal/atomic", "Load"}]
i.std[intrinsicKey{"sync/atomic", "LoadInt64"}] =
i.std[intrinsicKey{"runtime/internal/atomic", "Load64"}]
i.std[intrinsicKey{"sync/atomic", "LoadPointer"}] =
i.std[intrinsicKey{"runtime/internal/atomic", "Loadp"}]
i.std[intrinsicKey{"sync/atomic", "LoadUint32"}] =
i.std[intrinsicKey{"runtime/internal/atomic", "Load"}]
i.std[intrinsicKey{"sync/atomic", "LoadUint64"}] =
i.std[intrinsicKey{"runtime/internal/atomic", "Load64"}]
i.ptrSized[sizedIntrinsicKey{"sync/atomic", "LoadUintptr", 4}] =
i.std[intrinsicKey{"runtime/internal/atomic", "Load"}]
i.ptrSized[sizedIntrinsicKey{"sync/atomic", "LoadUintptr", 8}] =
i.std[intrinsicKey{"runtime/internal/atomic", "Load64"}]
i.std[intrinsicKey{"sync/atomic", "StoreInt32"}] =
i.std[intrinsicKey{"runtime/internal/atomic", "Store"}]
i.std[intrinsicKey{"sync/atomic", "StoreInt64"}] =
i.std[intrinsicKey{"runtime/internal/atomic", "Store64"}]
// Note: not StorePointer, that needs a write barrier. Same below for {CompareAnd}Swap.
i.std[intrinsicKey{"sync/atomic", "StoreUint32"}] =
i.std[intrinsicKey{"runtime/internal/atomic", "Store"}]
i.std[intrinsicKey{"sync/atomic", "StoreUint64"}] =
i.std[intrinsicKey{"runtime/internal/atomic", "Store64"}]
i.ptrSized[sizedIntrinsicKey{"sync/atomic", "StoreUintptr", 4}] =
i.std[intrinsicKey{"runtime/internal/atomic", "Store"}]
i.ptrSized[sizedIntrinsicKey{"sync/atomic", "StoreUintptr", 8}] =
i.std[intrinsicKey{"runtime/internal/atomic", "Store64"}]
i.std[intrinsicKey{"sync/atomic", "SwapInt32"}] =
i.std[intrinsicKey{"runtime/internal/atomic", "Xchg"}]
i.std[intrinsicKey{"sync/atomic", "SwapInt64"}] =
i.std[intrinsicKey{"runtime/internal/atomic", "Xchg64"}]
i.std[intrinsicKey{"sync/atomic", "SwapUint32"}] =
i.std[intrinsicKey{"runtime/internal/atomic", "Xchg"}]
i.std[intrinsicKey{"sync/atomic", "SwapUint64"}] =
i.std[intrinsicKey{"runtime/internal/atomic", "Xchg64"}]
i.ptrSized[sizedIntrinsicKey{"sync/atomic", "SwapUintptr", 4}] =
i.std[intrinsicKey{"runtime/internal/atomic", "Xchg"}]
i.ptrSized[sizedIntrinsicKey{"sync/atomic", "SwapUintptr", 8}] =
i.std[intrinsicKey{"runtime/internal/atomic", "Xchg64"}]
i.std[intrinsicKey{"sync/atomic", "CompareAndSwapInt32"}] =
i.std[intrinsicKey{"runtime/internal/atomic", "Cas"}]
i.std[intrinsicKey{"sync/atomic", "CompareAndSwapInt64"}] =
i.std[intrinsicKey{"runtime/internal/atomic", "Cas64"}]
i.std[intrinsicKey{"sync/atomic", "CompareAndSwapUint32"}] =
i.std[intrinsicKey{"runtime/internal/atomic", "Cas"}]
i.std[intrinsicKey{"sync/atomic", "CompareAndSwapUint64"}] =
i.std[intrinsicKey{"runtime/internal/atomic", "Cas64"}]
i.ptrSized[sizedIntrinsicKey{"sync/atomic", "CompareAndSwapUintptr", 4}] =
i.std[intrinsicKey{"runtime/internal/atomic", "Cas"}]
i.ptrSized[sizedIntrinsicKey{"sync/atomic", "CompareAndSwapUintptr", 8}] =
i.std[intrinsicKey{"runtime/internal/atomic", "Cas64"}]
i.std[intrinsicKey{"sync/atomic", "AddInt32"}] =
i.std[intrinsicKey{"runtime/internal/atomic", "Xadd"}]
i.std[intrinsicKey{"sync/atomic", "AddInt64"}] =
i.std[intrinsicKey{"runtime/internal/atomic", "Xadd64"}]
i.std[intrinsicKey{"sync/atomic", "AddUint32"}] =
i.std[intrinsicKey{"runtime/internal/atomic", "Xadd"}]
i.std[intrinsicKey{"sync/atomic", "AddUint64"}] =
i.std[intrinsicKey{"runtime/internal/atomic", "Xadd64"}]
i.ptrSized[sizedIntrinsicKey{"sync/atomic", "AddUintptr", 4}] =
i.std[intrinsicKey{"runtime/internal/atomic", "Xadd"}]
i.ptrSized[sizedIntrinsicKey{"sync/atomic", "AddUintptr", 8}] =
i.std[intrinsicKey{"runtime/internal/atomic", "Xadd64"}]
/******** math/big ********/
i.intSized[sizedIntrinsicKey{"math/big", "mulWW", 8}] =
enableOnArch(func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
return s.newValue2(ssa.OpMul64uhilo, ssa.MakeTuple(Types[TUINT64], Types[TUINT64]), args[0], args[1])
}, sys.AMD64)
i.intSized[sizedIntrinsicKey{"math/big", "divWW", 8}] =
enableOnArch(func(s *state, n *Node, args []*ssa.Value) *ssa.Value {
return s.newValue3(ssa.OpDiv128u, ssa.MakeTuple(Types[TUINT64], Types[TUINT64]), args[0], args[1], args[2])
}, sys.AMD64)
}
// findIntrinsic returns a function which builds the SSA equivalent of the
// function identified by the symbol sym. If sym is not an intrinsic call, returns nil.
func findIntrinsic(sym *Sym) intrinsicBuilder {
if ssa.IntrinsicsDisable {
return nil
}
if sym == nil || sym.Pkg == nil {
return nil
}
if intrinsics == nil {
intrinsicInit()
}
pkg := sym.Pkg.Path
if sym.Pkg == localpkg {
pkg = myimportpath
}
fn := sym.Name
f := intrinsics.std[intrinsicKey{pkg, fn}]
if f != nil {
return f
}
f = intrinsics.intSized[sizedIntrinsicKey{pkg, fn, Widthint}]
if f != nil {
return f
}
return intrinsics.ptrSized[sizedIntrinsicKey{pkg, fn, Widthptr}]
}
func isIntrinsicCall(n *Node) bool {
if n == nil || n.Left == nil {
return false
}
return findIntrinsic(n.Left.Sym) != nil
}
// intrinsicCall converts a call to a recognized intrinsic function into the intrinsic SSA operation.
func (s *state) intrinsicCall(n *Node) *ssa.Value {
v := findIntrinsic(n.Left.Sym)(s, n, s.intrinsicArgs(n))
if ssa.IntrinsicsDebug > 0 {
x := v
if x == nil {
x = s.mem()
}
if x.Op == ssa.OpSelect0 || x.Op == ssa.OpSelect1 {
x = x.Args[0]
}
Warnl(n.Pos, "intrinsic substitution for %v with %s", n.Left.Sym.Name, x.LongString())
}
return v
}
type callArg struct {
offset int64
v *ssa.Value
}
type byOffset []callArg
func (x byOffset) Len() int { return len(x) }
func (x byOffset) Swap(i, j int) { x[i], x[j] = x[j], x[i] }
func (x byOffset) Less(i, j int) bool {
return x[i].offset < x[j].offset
}
// intrinsicArgs extracts args from n, evaluates them to SSA values, and returns them.
func (s *state) intrinsicArgs(n *Node) []*ssa.Value {
// This code is complicated because of how walk transforms calls. For a call node,
// each entry in n.List is either an assignment to OINDREGSP which actually
// stores an arg, or an assignment to a temporary which computes an arg
// which is later assigned.
// The args can also be out of order.
// TODO: when walk goes away someday, this code can go away also.
var args []callArg
temps := map[*Node]*ssa.Value{}
for _, a := range n.List.Slice() {
if a.Op != OAS {
s.Fatalf("non-assignment as a function argument %s", opnames[a.Op])
}
l, r := a.Left, a.Right
switch l.Op {
case ONAME:
// Evaluate and store to "temporary".
// Walk ensures these temporaries are dead outside of n.
temps[l] = s.expr(r)
case OINDREGSP:
// Store a value to an argument slot.
var v *ssa.Value
if x, ok := temps[r]; ok {
// This is a previously computed temporary.
v = x
} else {
// This is an explicit value; evaluate it.
v = s.expr(r)
}
args = append(args, callArg{l.Xoffset, v})
default:
s.Fatalf("function argument assignment target not allowed: %s", opnames[l.Op])
}
}
sort.Sort(byOffset(args))
res := make([]*ssa.Value, len(args))
for i, a := range args {
res[i] = a.v
}
return res
}
// Calls the function n using the specified call type.
// Returns the address of the return value (or nil if none).
func (s *state) call(n *Node, k callKind) *ssa.Value {
var sym *Sym // target symbol (if static)
var closure *ssa.Value // ptr to closure to run (if dynamic)
var codeptr *ssa.Value // ptr to target code (if dynamic)
var rcvr *ssa.Value // receiver to set
fn := n.Left
switch n.Op {
case OCALLFUNC:
if k == callNormal && fn.Op == ONAME && fn.Class == PFUNC {
sym = fn.Sym
break
}
closure = s.expr(fn)
case OCALLMETH:
if fn.Op != ODOTMETH {
Fatalf("OCALLMETH: n.Left not an ODOTMETH: %v", fn)
}
if k == callNormal {
sym = fn.Sym
break
}
// Make a name n2 for the function.
// fn.Sym might be sync.(*Mutex).Unlock.
// Make a PFUNC node out of that, then evaluate it.
// We get back an SSA value representing &sync.(*Mutex).Unlock·f.
// We can then pass that to defer or go.
n2 := newname(fn.Sym)
n2.Class = PFUNC
n2.Pos = fn.Pos
n2.Type = Types[TUINT8] // dummy type for a static closure. Could use runtime.funcval if we had it.
closure = s.expr(n2)
// Note: receiver is already assigned in n.List, so we don't
// want to set it here.
case OCALLINTER:
if fn.Op != ODOTINTER {
Fatalf("OCALLINTER: n.Left not an ODOTINTER: %v", fn.Op)
}
i := s.expr(fn.Left)
itab := s.newValue1(ssa.OpITab, Types[TUINTPTR], i)
if k != callNormal {
s.nilCheck(itab)
}
itabidx := fn.Xoffset + 3*int64(Widthptr) + 8 // offset of fun field in runtime.itab
itab = s.newValue1I(ssa.OpOffPtr, ptrto(Types[TUINTPTR]), itabidx, itab)
if k == callNormal {
codeptr = s.newValue2(ssa.OpLoad, Types[TUINTPTR], itab, s.mem())
} else {
closure = itab
}
rcvr = s.newValue1(ssa.OpIData, Types[TUINTPTR], i)
}
dowidth(fn.Type)
stksize := fn.Type.ArgWidth() // includes receiver
// Run all argument assignments. The arg slots have already
// been offset by the appropriate amount (+2*widthptr for go/defer,
// +widthptr for interface calls).
// For OCALLMETH, the receiver is set in these statements.
s.stmtList(n.List)
// Set receiver (for interface calls)
if rcvr != nil {
argStart := Ctxt.FixedFrameSize()
if k != callNormal {
argStart += int64(2 * Widthptr)
}
addr := s.entryNewValue1I(ssa.OpOffPtr, ptrto(Types[TUINTPTR]), argStart, s.sp)
s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, int64(Widthptr), addr, rcvr, s.mem())
}
// Defer/go args
if k != callNormal {
// Write argsize and closure (args to Newproc/Deferproc).
argStart := Ctxt.FixedFrameSize()
argsize := s.constInt32(Types[TUINT32], int32(stksize))
addr := s.entryNewValue1I(ssa.OpOffPtr, ptrto(Types[TUINT32]), argStart, s.sp)
s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, 4, addr, argsize, s.mem())
addr = s.entryNewValue1I(ssa.OpOffPtr, ptrto(Types[TUINTPTR]), argStart+int64(Widthptr), s.sp)
s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, int64(Widthptr), addr, closure, s.mem())
stksize += 2 * int64(Widthptr)
}
// call target
var call *ssa.Value
switch {
case k == callDefer:
call = s.newValue1(ssa.OpDeferCall, ssa.TypeMem, s.mem())
case k == callGo:
call = s.newValue1(ssa.OpGoCall, ssa.TypeMem, s.mem())
case closure != nil:
codeptr = s.newValue2(ssa.OpLoad, Types[TUINTPTR], closure, s.mem())
call = s.newValue3(ssa.OpClosureCall, ssa.TypeMem, codeptr, closure, s.mem())
case codeptr != nil:
call = s.newValue2(ssa.OpInterCall, ssa.TypeMem, codeptr, s.mem())
case sym != nil:
call = s.newValue1A(ssa.OpStaticCall, ssa.TypeMem, Linksym(sym), s.mem())
default:
Fatalf("bad call type %v %v", n.Op, n)
}
call.AuxInt = stksize // Call operations carry the argsize of the callee along with them
s.vars[&memVar] = call
// Finish block for defers
if k == callDefer {
b := s.endBlock()
b.Kind = ssa.BlockDefer
b.SetControl(call)
bNext := s.f.NewBlock(ssa.BlockPlain)
b.AddEdgeTo(bNext)
// Add recover edge to exit code.
r := s.f.NewBlock(ssa.BlockPlain)
s.startBlock(r)
s.exit()
b.AddEdgeTo(r)
b.Likely = ssa.BranchLikely
s.startBlock(bNext)
}
res := n.Left.Type.Results()
if res.NumFields() == 0 || k != callNormal {
// call has no return value. Continue with the next statement.
return nil
}
fp := res.Field(0)
return s.entryNewValue1I(ssa.OpOffPtr, ptrto(fp.Type), fp.Offset+Ctxt.FixedFrameSize(), s.sp)
}
// etypesign returns the signed-ness of e, for integer/pointer etypes.
// -1 means signed, +1 means unsigned, 0 means non-integer/non-pointer.
func etypesign(e EType) int8 {
switch e {
case TINT8, TINT16, TINT32, TINT64, TINT:
return -1
case TUINT8, TUINT16, TUINT32, TUINT64, TUINT, TUINTPTR, TUNSAFEPTR:
return +1
}
return 0
}
// lookupSymbol is used to retrieve the symbol (Extern, Arg or Auto) used for a particular node.
// This improves the effectiveness of cse by using the same Aux values for the
// same symbols.
func (s *state) lookupSymbol(n *Node, sym interface{}) interface{} {
switch sym.(type) {
default:
s.Fatalf("sym %v is of uknown type %T", sym, sym)
case *ssa.ExternSymbol, *ssa.ArgSymbol, *ssa.AutoSymbol:
// these are the only valid types
}
if lsym, ok := s.varsyms[n]; ok {
return lsym
} else {
s.varsyms[n] = sym
return sym
}
}
// addr converts the address of the expression n to SSA, adds it to s and returns the SSA result.
// Also returns a bool reporting whether the returned value is "volatile", that is it
// points to the outargs section and thus the referent will be clobbered by any call.
// The value that the returned Value represents is guaranteed to be non-nil.
// If bounded is true then this address does not require a nil check for its operand
// even if that would otherwise be implied.
func (s *state) addr(n *Node, bounded bool) (*ssa.Value, bool) {
t := ptrto(n.Type)
switch n.Op {
case ONAME:
switch n.Class {
case PEXTERN:
// global variable
aux := s.lookupSymbol(n, &ssa.ExternSymbol{Typ: n.Type, Sym: Linksym(n.Sym)})
v := s.entryNewValue1A(ssa.OpAddr, t, aux, s.sb)
// TODO: Make OpAddr use AuxInt as well as Aux.
if n.Xoffset != 0 {
v = s.entryNewValue1I(ssa.OpOffPtr, v.Type, n.Xoffset, v)
}
return v, false
case PPARAM:
// parameter slot
v := s.decladdrs[n]
if v != nil {
return v, false
}
if n == nodfp {
// Special arg that points to the frame pointer (Used by ORECOVER).
aux := s.lookupSymbol(n, &ssa.ArgSymbol{Typ: n.Type, Node: n})
return s.entryNewValue1A(ssa.OpAddr, t, aux, s.sp), false
}
s.Fatalf("addr of undeclared ONAME %v. declared: %v", n, s.decladdrs)
return nil, false
case PAUTO:
aux := s.lookupSymbol(n, &ssa.AutoSymbol{Typ: n.Type, Node: n})
return s.newValue1A(ssa.OpAddr, t, aux, s.sp), false
case PPARAMOUT: // Same as PAUTO -- cannot generate LEA early.
// ensure that we reuse symbols for out parameters so
// that cse works on their addresses
aux := s.lookupSymbol(n, &ssa.ArgSymbol{Typ: n.Type, Node: n})
return s.newValue1A(ssa.OpAddr, t, aux, s.sp), false
default:
s.Fatalf("variable address class %v not implemented", classnames[n.Class])
return nil, false
}
case OINDREGSP:
// indirect off REGSP
// used for storing/loading arguments/returns to/from callees
return s.entryNewValue1I(ssa.OpOffPtr, t, n.Xoffset, s.sp), true
case OINDEX:
if n.Left.Type.IsSlice() {
a := s.expr(n.Left)
i := s.expr(n.Right)
i = s.extendIndex(i, panicindex)
len := s.newValue1(ssa.OpSliceLen, Types[TINT], a)
if !n.Bounded {
s.boundsCheck(i, len)
}
p := s.newValue1(ssa.OpSlicePtr, t, a)
return s.newValue2(ssa.OpPtrIndex, t, p, i), false
} else { // array
a, isVolatile := s.addr(n.Left, bounded)
i := s.expr(n.Right)
i = s.extendIndex(i, panicindex)
len := s.constInt(Types[TINT], n.Left.Type.NumElem())
if !n.Bounded {
s.boundsCheck(i, len)
}
return s.newValue2(ssa.OpPtrIndex, ptrto(n.Left.Type.Elem()), a, i), isVolatile
}
case OIND:
return s.exprPtr(n.Left, bounded, n.Pos), false
case ODOT:
p, isVolatile := s.addr(n.Left, bounded)
return s.newValue1I(ssa.OpOffPtr, t, n.Xoffset, p), isVolatile
case ODOTPTR:
p := s.exprPtr(n.Left, bounded, n.Pos)
return s.newValue1I(ssa.OpOffPtr, t, n.Xoffset, p), false
case OCLOSUREVAR:
return s.newValue1I(ssa.OpOffPtr, t, n.Xoffset,
s.entryNewValue0(ssa.OpGetClosurePtr, ptrto(Types[TUINT8]))), false
case OCONVNOP:
addr, isVolatile := s.addr(n.Left, bounded)
return s.newValue1(ssa.OpCopy, t, addr), isVolatile // ensure that addr has the right type
case OCALLFUNC, OCALLINTER, OCALLMETH:
return s.call(n, callNormal), true
case ODOTTYPE:
v, _ := s.dottype(n, false)
if v.Op != ssa.OpLoad {
s.Fatalf("dottype of non-load")
}
if v.Args[1] != s.mem() {
s.Fatalf("memory no longer live from dottype load")
}
return v.Args[0], false
default:
s.Fatalf("unhandled addr %v", n.Op)
return nil, false
}
}
// canSSA reports whether n is SSA-able.
// n must be an ONAME (or an ODOT sequence with an ONAME base).
func (s *state) canSSA(n *Node) bool {
if Debug['N'] != 0 {
return false
}
for n.Op == ODOT || (n.Op == OINDEX && n.Left.Type.IsArray()) {
n = n.Left
}
if n.Op != ONAME {
return false
}
if n.Addrtaken {
return false
}
if n.isParamHeapCopy() {
return false
}
if n.Class == PAUTOHEAP {
Fatalf("canSSA of PAUTOHEAP %v", n)
}
switch n.Class {
case PEXTERN:
return false
case PPARAMOUT:
if hasdefer {
// TODO: handle this case? Named return values must be
// in memory so that the deferred function can see them.
// Maybe do: if !strings.HasPrefix(n.String(), "~") { return false }
// Or maybe not, see issue 18860. Even unnamed return values
// must be written back so if a defer recovers, the caller can see them.
return false
}
if s.cgoUnsafeArgs {
// Cgo effectively takes the address of all result args,
// but the compiler can't see that.
return false
}
}
if n.Class == PPARAM && n.String() == ".this" {
// wrappers generated by genwrapper need to update
// the .this pointer in place.
// TODO: treat as a PPARMOUT?
return false
}
return canSSAType(n.Type)
// TODO: try to make more variables SSAable?
}
// canSSA reports whether variables of type t are SSA-able.
func canSSAType(t *Type) bool {
dowidth(t)
if t.Width > int64(4*Widthptr) {
// 4*Widthptr is an arbitrary constant. We want it
// to be at least 3*Widthptr so slices can be registerized.
// Too big and we'll introduce too much register pressure.
return false
}
switch t.Etype {
case TARRAY:
// We can't do larger arrays because dynamic indexing is
// not supported on SSA variables.
// TODO: allow if all indexes are constant.
if t.NumElem() == 0 {
return true
}
if t.NumElem() == 1 {
return canSSAType(t.Elem())
}
return false
case TSTRUCT:
if t.NumFields() > ssa.MaxStruct {
return false
}
for _, t1 := range t.Fields().Slice() {
if !canSSAType(t1.Type) {
return false
}
}
return true
default:
return true
}
}
// exprPtr evaluates n to a pointer and nil-checks it.
func (s *state) exprPtr(n *Node, bounded bool, lineno src.XPos) *ssa.Value {
p := s.expr(n)
if bounded || n.NonNil {
if s.f.Config.Debug_checknil() && lineno.Line() > 1 {
s.f.Config.Warnl(lineno, "removed nil check")
}
return p
}
s.nilCheck(p)
return p
}
// nilCheck generates nil pointer checking code.
// Used only for automatically inserted nil checks,
// not for user code like 'x != nil'.
func (s *state) nilCheck(ptr *ssa.Value) {
if disable_checknil != 0 {
return
}
s.newValue2(ssa.OpNilCheck, ssa.TypeVoid, ptr, s.mem())
}
// boundsCheck generates bounds checking code. Checks if 0 <= idx < len, branches to exit if not.
// Starts a new block on return.
// idx is already converted to full int width.
func (s *state) boundsCheck(idx, len *ssa.Value) {
if Debug['B'] != 0 {
return
}
// bounds check
cmp := s.newValue2(ssa.OpIsInBounds, Types[TBOOL], idx, len)
s.check(cmp, panicindex)
}
// sliceBoundsCheck generates slice bounds checking code. Checks if 0 <= idx <= len, branches to exit if not.
// Starts a new block on return.
// idx and len are already converted to full int width.
func (s *state) sliceBoundsCheck(idx, len *ssa.Value) {
if Debug['B'] != 0 {
return
}
// bounds check
cmp := s.newValue2(ssa.OpIsSliceInBounds, Types[TBOOL], idx, len)
s.check(cmp, panicslice)
}
// If cmp (a bool) is false, panic using the given function.
func (s *state) check(cmp *ssa.Value, fn *obj.LSym) {
b := s.endBlock()
b.Kind = ssa.BlockIf
b.SetControl(cmp)
b.Likely = ssa.BranchLikely
bNext := s.f.NewBlock(ssa.BlockPlain)
line := s.peekPos()
bPanic := s.panics[funcLine{fn, line}]
if bPanic == nil {
bPanic = s.f.NewBlock(ssa.BlockPlain)
s.panics[funcLine{fn, line}] = bPanic
s.startBlock(bPanic)
// The panic call takes/returns memory to ensure that the right
// memory state is observed if the panic happens.
s.rtcall(fn, false, nil)
}
b.AddEdgeTo(bNext)
b.AddEdgeTo(bPanic)
s.startBlock(bNext)
}
func (s *state) intDivide(n *Node, a, b *ssa.Value) *ssa.Value {
needcheck := true
switch b.Op {
case ssa.OpConst8, ssa.OpConst16, ssa.OpConst32, ssa.OpConst64:
if b.AuxInt != 0 {
needcheck = false
}
}
if needcheck {
// do a size-appropriate check for zero
cmp := s.newValue2(s.ssaOp(ONE, n.Type), Types[TBOOL], b, s.zeroVal(n.Type))
s.check(cmp, panicdivide)
}
return s.newValue2(s.ssaOp(n.Op, n.Type), a.Type, a, b)
}
// rtcall issues a call to the given runtime function fn with the listed args.
// Returns a slice of results of the given result types.
// The call is added to the end of the current block.
// If returns is false, the block is marked as an exit block.
func (s *state) rtcall(fn *obj.LSym, returns bool, results []*Type, args ...*ssa.Value) []*ssa.Value {
// Write args to the stack
off := Ctxt.FixedFrameSize()
for _, arg := range args {
t := arg.Type
off = Rnd(off, t.Alignment())
ptr := s.sp
if off != 0 {
ptr = s.newValue1I(ssa.OpOffPtr, t.PtrTo(), off, s.sp)
}
size := t.Size()
s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, size, ptr, arg, s.mem())
off += size
}
off = Rnd(off, int64(Widthptr))
if Thearch.LinkArch.Name == "amd64p32" {
// amd64p32 wants 8-byte alignment of the start of the return values.
off = Rnd(off, 8)
}
// Issue call
call := s.newValue1A(ssa.OpStaticCall, ssa.TypeMem, fn, s.mem())
s.vars[&memVar] = call
if !returns {
// Finish block
b := s.endBlock()
b.Kind = ssa.BlockExit
b.SetControl(call)
call.AuxInt = off - Ctxt.FixedFrameSize()
if len(results) > 0 {
Fatalf("panic call can't have results")
}
return nil
}
// Load results
res := make([]*ssa.Value, len(results))
for i, t := range results {
off = Rnd(off, t.Alignment())
ptr := s.sp
if off != 0 {
ptr = s.newValue1I(ssa.OpOffPtr, ptrto(t), off, s.sp)
}
res[i] = s.newValue2(ssa.OpLoad, t, ptr, s.mem())
off += t.Size()
}
off = Rnd(off, int64(Widthptr))
// Remember how much callee stack space we needed.
call.AuxInt = off
return res
}
// insertWBmove inserts the assignment *left = *right including a write barrier.
// t is the type being assigned.
// If right == nil, then we're zeroing *left.
func (s *state) insertWBmove(t *Type, left, right *ssa.Value, rightIsVolatile bool) {
// if writeBarrier.enabled {
// typedmemmove(&t, left, right)
// } else {
// *left = *right
// }
//
// or
//
// if writeBarrier.enabled {
// typedmemclr(&t, left)
// } else {
// *left = zeroValue
// }
if s.noWB {
s.Error("write barrier prohibited")
}
if !s.WBPos.IsKnown() {
s.WBPos = left.Pos
}
var val *ssa.Value
if right == nil {
val = s.newValue2I(ssa.OpZeroWB, ssa.TypeMem, sizeAlignAuxInt(t), left, s.mem())
} else {
var op ssa.Op
if rightIsVolatile {
op = ssa.OpMoveWBVolatile
} else {
op = ssa.OpMoveWB
}
val = s.newValue3I(op, ssa.TypeMem, sizeAlignAuxInt(t), left, right, s.mem())
}
val.Aux = &ssa.ExternSymbol{Typ: Types[TUINTPTR], Sym: Linksym(typenamesym(t))}
s.vars[&memVar] = val
}
// insertWBstore inserts the assignment *left = right including a write barrier.
// t is the type being assigned.
func (s *state) insertWBstore(t *Type, left, right *ssa.Value, skip skipMask) {
// store scalar fields
// if writeBarrier.enabled {
// writebarrierptr for pointer fields
// } else {
// store pointer fields
// }
if s.noWB {
s.Error("write barrier prohibited")
}
if !s.WBPos.IsKnown() {
s.WBPos = left.Pos
}
s.storeTypeScalars(t, left, right, skip)
s.storeTypePtrsWB(t, left, right)
}
// do *left = right for all scalar (non-pointer) parts of t.
func (s *state) storeTypeScalars(t *Type, left, right *ssa.Value, skip skipMask) {
switch {
case t.IsBoolean() || t.IsInteger() || t.IsFloat() || t.IsComplex():
s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, t.Size(), left, right, s.mem())
case t.IsPtrShaped():
// no scalar fields.
case t.IsString():
if skip&skipLen != 0 {
return
}
len := s.newValue1(ssa.OpStringLen, Types[TINT], right)
lenAddr := s.newValue1I(ssa.OpOffPtr, ptrto(Types[TINT]), s.config.IntSize, left)
s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, s.config.IntSize, lenAddr, len, s.mem())
case t.IsSlice():
if skip&skipLen == 0 {
len := s.newValue1(ssa.OpSliceLen, Types[TINT], right)
lenAddr := s.newValue1I(ssa.OpOffPtr, ptrto(Types[TINT]), s.config.IntSize, left)
s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, s.config.IntSize, lenAddr, len, s.mem())
}
if skip&skipCap == 0 {
cap := s.newValue1(ssa.OpSliceCap, Types[TINT], right)
capAddr := s.newValue1I(ssa.OpOffPtr, ptrto(Types[TINT]), 2*s.config.IntSize, left)
s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, s.config.IntSize, capAddr, cap, s.mem())
}
case t.IsInterface():
// itab field doesn't need a write barrier (even though it is a pointer).
itab := s.newValue1(ssa.OpITab, ptrto(Types[TUINT8]), right)
s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, s.config.IntSize, left, itab, s.mem())
case t.IsStruct():
n := t.NumFields()
for i := 0; i < n; i++ {
ft := t.FieldType(i)
addr := s.newValue1I(ssa.OpOffPtr, ft.PtrTo(), t.FieldOff(i), left)
val := s.newValue1I(ssa.OpStructSelect, ft, int64(i), right)
s.storeTypeScalars(ft.(*Type), addr, val, 0)
}
case t.IsArray() && t.NumElem() == 0:
// nothing
case t.IsArray() && t.NumElem() == 1:
s.storeTypeScalars(t.Elem(), left, s.newValue1I(ssa.OpArraySelect, t.Elem(), 0, right), 0)
default:
s.Fatalf("bad write barrier type %v", t)
}
}
// do *left = right for all pointer parts of t.
func (s *state) storeTypePtrs(t *Type, left, right *ssa.Value) {
switch {
case t.IsPtrShaped():
s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, s.config.PtrSize, left, right, s.mem())
case t.IsString():
ptr := s.newValue1(ssa.OpStringPtr, ptrto(Types[TUINT8]), right)
s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, s.config.PtrSize, left, ptr, s.mem())
case t.IsSlice():
ptr := s.newValue1(ssa.OpSlicePtr, ptrto(Types[TUINT8]), right)
s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, s.config.PtrSize, left, ptr, s.mem())
case t.IsInterface():
// itab field is treated as a scalar.
idata := s.newValue1(ssa.OpIData, ptrto(Types[TUINT8]), right)
idataAddr := s.newValue1I(ssa.OpOffPtr, ptrto(Types[TUINT8]), s.config.PtrSize, left)
s.vars[&memVar] = s.newValue3I(ssa.OpStore, ssa.TypeMem, s.config.PtrSize, idataAddr, idata, s.mem())
case t.IsStruct():
n := t.NumFields()
for i := 0; i < n; i++ {
ft := t.FieldType(i)
if !haspointers(ft.(*Type)) {
continue
}
addr := s.newValue1I(ssa.OpOffPtr, ft.PtrTo(), t.FieldOff(i), left)
val := s.newValue1I(ssa.OpStructSelect, ft, int64(i), right)
s.storeTypePtrs(ft.(*Type), addr, val)
}
case t.IsArray() && t.NumElem() == 0:
// nothing
case t.IsArray() && t.NumElem() == 1:
s.storeTypePtrs(t.Elem(), left, s.newValue1I(ssa.OpArraySelect, t.Elem(), 0, right))
default:
s.Fatalf("bad write barrier type %v", t)
}
}
// do *left = right for all pointer parts of t, with write barriers if necessary.
func (s *state) storeTypePtrsWB(t *Type, left, right *ssa.Value) {
switch {
case t.IsPtrShaped():
s.vars[&memVar] = s.newValue3I(ssa.OpStoreWB, ssa.TypeMem, s.config.PtrSize, left, right, s.mem())
case t.IsString():
ptr := s.newValue1(ssa.OpStringPtr, ptrto(Types[TUINT8]), right)
s.vars[&memVar] = s.newValue3I(ssa.OpStoreWB, ssa.TypeMem, s.config.PtrSize, left, ptr, s.mem())
case t.IsSlice():
ptr := s.newValue1(ssa.OpSlicePtr, ptrto(Types[TUINT8]), right)
s.vars[&memVar] = s.newValue3I(ssa.OpStoreWB, ssa.TypeMem, s.config.PtrSize, left, ptr, s.mem())
case t.IsInterface():
// itab field is treated as a scalar.
idata := s.newValue1(ssa.OpIData, ptrto(Types[TUINT8]), right)
idataAddr := s.newValue1I(ssa.OpOffPtr, ptrto(Types[TUINT8]), s.config.PtrSize, left)
s.vars[&memVar] = s.newValue3I(ssa.OpStoreWB, ssa.TypeMem, s.config.PtrSize, idataAddr, idata, s.mem())
case t.IsStruct():
n := t.NumFields()
for i := 0; i < n; i++ {
ft := t.FieldType(i)
if !haspointers(ft.(*Type)) {
continue
}
addr := s.newValue1I(ssa.OpOffPtr, ft.PtrTo(), t.FieldOff(i), left)
val := s.newValue1I(ssa.OpStructSelect, ft, int64(i), right)
s.storeTypePtrsWB(ft.(*Type), addr, val)
}
case t.IsArray() && t.NumElem() == 0:
// nothing
case t.IsArray() && t.NumElem() == 1:
s.storeTypePtrsWB(t.Elem(), left, s.newValue1I(ssa.OpArraySelect, t.Elem(), 0, right))
default:
s.Fatalf("bad write barrier type %v", t)
}
}
// slice computes the slice v[i:j:k] and returns ptr, len, and cap of result.
// i,j,k may be nil, in which case they are set to their default value.
// t is a slice, ptr to array, or string type.
func (s *state) slice(t *Type, v, i, j, k *ssa.Value) (p, l, c *ssa.Value) {
var elemtype *Type
var ptrtype *Type
var ptr *ssa.Value
var len *ssa.Value
var cap *ssa.Value
zero := s.constInt(Types[TINT], 0)
switch {
case t.IsSlice():
elemtype = t.Elem()
ptrtype = ptrto(elemtype)
ptr = s.newValue1(ssa.OpSlicePtr, ptrtype, v)
len = s.newValue1(ssa.OpSliceLen, Types[TINT], v)
cap = s.newValue1(ssa.OpSliceCap, Types[TINT], v)
case t.IsString():
elemtype = Types[TUINT8]
ptrtype = ptrto(elemtype)
ptr = s.newValue1(ssa.OpStringPtr, ptrtype, v)
len = s.newValue1(ssa.OpStringLen, Types[TINT], v)
cap = len
case t.IsPtr():
if !t.Elem().IsArray() {
s.Fatalf("bad ptr to array in slice %v\n", t)
}
elemtype = t.Elem().Elem()
ptrtype = ptrto(elemtype)
s.nilCheck(v)
ptr = v
len = s.constInt(Types[TINT], t.Elem().NumElem())
cap = len
default:
s.Fatalf("bad type in slice %v\n", t)
}
// Set default values
if i == nil {
i = zero
}
if j == nil {
j = len
}
if k == nil {
k = cap
}
// Panic if slice indices are not in bounds.
s.sliceBoundsCheck(i, j)
if j != k {
s.sliceBoundsCheck(j, k)
}
if k != cap {
s.sliceBoundsCheck(k, cap)
}
// Generate the following code assuming that indexes are in bounds.
// The masking is to make sure that we don't generate a slice
// that points to the next object in memory.
// rlen = j - i
// rcap = k - i
// delta = i * elemsize
// rptr = p + delta&mask(rcap)
// result = (SliceMake rptr rlen rcap)
// where mask(x) is 0 if x==0 and -1 if x>0.
subOp := s.ssaOp(OSUB, Types[TINT])
mulOp := s.ssaOp(OMUL, Types[TINT])
andOp := s.ssaOp(OAND, Types[TINT])
rlen := s.newValue2(subOp, Types[TINT], j, i)
var rcap *ssa.Value
switch {
case t.IsString():
// Capacity of the result is unimportant. However, we use
// rcap to test if we've generated a zero-length slice.
// Use length of strings for that.
rcap = rlen
case j == k:
rcap = rlen
default:
rcap = s.newValue2(subOp, Types[TINT], k, i)
}
var rptr *ssa.Value
if (i.Op == ssa.OpConst64 || i.Op == ssa.OpConst32) && i.AuxInt == 0 {
// No pointer arithmetic necessary.
rptr = ptr
} else {
// delta = # of bytes to offset pointer by.
delta := s.newValue2(mulOp, Types[TINT], i, s.constInt(Types[TINT], elemtype.Width))
// If we're slicing to the point where the capacity is zero,
// zero out the delta.
mask := s.newValue1(ssa.OpSlicemask, Types[TINT], rcap)
delta = s.newValue2(andOp, Types[TINT], delta, mask)
// Compute rptr = ptr + delta
rptr = s.newValue2(ssa.OpAddPtr, ptrtype, ptr, delta)
}
return rptr, rlen, rcap
}
type u642fcvtTab struct {
geq, cvt2F, and, rsh, or, add ssa.Op
one func(*state, ssa.Type, int64) *ssa.Value
}
var u64_f64 u642fcvtTab = u642fcvtTab{
geq: ssa.OpGeq64,
cvt2F: ssa.OpCvt64to64F,
and: ssa.OpAnd64,
rsh: ssa.OpRsh64Ux64,
or: ssa.OpOr64,
add: ssa.OpAdd64F,
one: (*state).constInt64,
}
var u64_f32 u642fcvtTab = u642fcvtTab{
geq: ssa.OpGeq64,
cvt2F: ssa.OpCvt64to32F,
and: ssa.OpAnd64,
rsh: ssa.OpRsh64Ux64,
or: ssa.OpOr64,
add: ssa.OpAdd32F,
one: (*state).constInt64,
}
func (s *state) uint64Tofloat64(n *Node, x *ssa.Value, ft, tt *Type) *ssa.Value {
return s.uint64Tofloat(&u64_f64, n, x, ft, tt)
}
func (s *state) uint64Tofloat32(n *Node, x *ssa.Value, ft, tt *Type) *ssa.Value {
return s.uint64Tofloat(&u64_f32, n, x, ft, tt)
}
func (s *state) uint64Tofloat(cvttab *u642fcvtTab, n *Node, x *ssa.Value, ft, tt *Type) *ssa.Value {
// if x >= 0 {
// result = (floatY) x
// } else {
// y = uintX(x) ; y = x & 1
// z = uintX(x) ; z = z >> 1
// z = z >> 1
// z = z | y
// result = floatY(z)
// result = result + result
// }
//
// Code borrowed from old code generator.
// What's going on: large 64-bit "unsigned" looks like
// negative number to hardware's integer-to-float
// conversion. However, because the mantissa is only
// 63 bits, we don't need the LSB, so instead we do an
// unsigned right shift (divide by two), convert, and
// double. However, before we do that, we need to be
// sure that we do not lose a "1" if that made the
// difference in the resulting rounding. Therefore, we
// preserve it, and OR (not ADD) it back in. The case
// that matters is when the eleven discarded bits are
// equal to 10000000001; that rounds up, and the 1 cannot
// be lost else it would round down if the LSB of the
// candidate mantissa is 0.
cmp := s.newValue2(cvttab.geq, Types[TBOOL], x, s.zeroVal(ft))
b := s.endBlock()
b.Kind = ssa.BlockIf
b.SetControl(cmp)
b.Likely = ssa.BranchLikely
bThen := s.f.NewBlock(ssa.BlockPlain)
bElse := s.f.NewBlock(ssa.BlockPlain)
bAfter := s.f.NewBlock(ssa.BlockPlain)
b.AddEdgeTo(bThen)
s.startBlock(bThen)
a0 := s.newValue1(cvttab.cvt2F, tt, x)
s.vars[n] = a0
s.endBlock()
bThen.AddEdgeTo(bAfter)
b.AddEdgeTo(bElse)
s.startBlock(bElse)
one := cvttab.one(s, ft, 1)
y := s.newValue2(cvttab.and, ft, x, one)
z := s.newValue2(cvttab.rsh, ft, x, one)
z = s.newValue2(cvttab.or, ft, z, y)
a := s.newValue1(cvttab.cvt2F, tt, z)
a1 := s.newValue2(cvttab.add, tt, a, a)
s.vars[n] = a1
s.endBlock()
bElse.AddEdgeTo(bAfter)
s.startBlock(bAfter)
return s.variable(n, n.Type)
}
type u322fcvtTab struct {
cvtI2F, cvtF2F ssa.Op
}
var u32_f64 u322fcvtTab = u322fcvtTab{
cvtI2F: ssa.OpCvt32to64F,
cvtF2F: ssa.OpCopy,
}
var u32_f32 u322fcvtTab = u322fcvtTab{
cvtI2F: ssa.OpCvt32to32F,
cvtF2F: ssa.OpCvt64Fto32F,
}
func (s *state) uint32Tofloat64(n *Node, x *ssa.Value, ft, tt *Type) *ssa.Value {
return s.uint32Tofloat(&u32_f64, n, x, ft, tt)
}
func (s *state) uint32Tofloat32(n *Node, x *ssa.Value, ft, tt *Type) *ssa.Value {
return s.uint32Tofloat(&u32_f32, n, x, ft, tt)
}
func (s *state) uint32Tofloat(cvttab *u322fcvtTab, n *Node, x *ssa.Value, ft, tt *Type) *ssa.Value {
// if x >= 0 {
// result = floatY(x)
// } else {
// result = floatY(float64(x) + (1<<32))
// }
cmp := s.newValue2(ssa.OpGeq32, Types[TBOOL], x, s.zeroVal(ft))
b := s.endBlock()
b.Kind = ssa.BlockIf
b.SetControl(cmp)
b.Likely = ssa.BranchLikely
bThen := s.f.NewBlock(ssa.BlockPlain)
bElse := s.f.NewBlock(ssa.BlockPlain)
bAfter := s.f.NewBlock(ssa.BlockPlain)
b.AddEdgeTo(bThen)
s.startBlock(bThen)
a0 := s.newValue1(cvttab.cvtI2F, tt, x)
s.vars[n] = a0
s.endBlock()
bThen.AddEdgeTo(bAfter)
b.AddEdgeTo(bElse)
s.startBlock(bElse)
a1 := s.newValue1(ssa.OpCvt32to64F, Types[TFLOAT64], x)
twoToThe32 := s.constFloat64(Types[TFLOAT64], float64(1<<32))
a2 := s.newValue2(ssa.OpAdd64F, Types[TFLOAT64], a1, twoToThe32)
a3 := s.newValue1(cvttab.cvtF2F, tt, a2)
s.vars[n] = a3
s.endBlock()
bElse.AddEdgeTo(bAfter)
s.startBlock(bAfter)
return s.variable(n, n.Type)
}
// referenceTypeBuiltin generates code for the len/cap builtins for maps and channels.
func (s *state) referenceTypeBuiltin(n *Node, x *ssa.Value) *ssa.Value {
if !n.Left.Type.IsMap() && !n.Left.Type.IsChan() {
s.Fatalf("node must be a map or a channel")
}
// if n == nil {
// return 0
// } else {
// // len
// return *((*int)n)
// // cap
// return *(((*int)n)+1)
// }
lenType := n.Type
nilValue := s.constNil(Types[TUINTPTR])
cmp := s.newValue2(ssa.OpEqPtr, Types[TBOOL], x, nilValue)
b := s.endBlock()
b.Kind = ssa.BlockIf
b.SetControl(cmp)
b.Likely = ssa.BranchUnlikely
bThen := s.f.NewBlock(ssa.BlockPlain)
bElse := s.f.NewBlock(ssa.BlockPlain)
bAfter := s.f.NewBlock(ssa.BlockPlain)
// length/capacity of a nil map/chan is zero
b.AddEdgeTo(bThen)
s.startBlock(bThen)
s.vars[n] = s.zeroVal(lenType)
s.endBlock()
bThen.AddEdgeTo(bAfter)
b.AddEdgeTo(bElse)
s.startBlock(bElse)
if n.Op == OLEN {
// length is stored in the first word for map/chan
s.vars[n] = s.newValue2(ssa.OpLoad, lenType, x, s.mem())
} else if n.Op == OCAP {
// capacity is stored in the second word for chan
sw := s.newValue1I(ssa.OpOffPtr, lenType.PtrTo(), lenType.Width, x)
s.vars[n] = s.newValue2(ssa.OpLoad, lenType, sw, s.mem())
} else {
s.Fatalf("op must be OLEN or OCAP")
}
s.endBlock()
bElse.AddEdgeTo(bAfter)
s.startBlock(bAfter)
return s.variable(n, lenType)
}
type f2uCvtTab struct {
ltf, cvt2U, subf, or ssa.Op
floatValue func(*state, ssa.Type, float64) *ssa.Value
intValue func(*state, ssa.Type, int64) *ssa.Value
cutoff uint64
}
var f32_u64 f2uCvtTab = f2uCvtTab{
ltf: ssa.OpLess32F,
cvt2U: ssa.OpCvt32Fto64,
subf: ssa.OpSub32F,
or: ssa.OpOr64,
floatValue: (*state).constFloat32,
intValue: (*state).constInt64,
cutoff: 9223372036854775808,
}
var f64_u64 f2uCvtTab = f2uCvtTab{
ltf: ssa.OpLess64F,
cvt2U: ssa.OpCvt64Fto64,
subf: ssa.OpSub64F,
or: ssa.OpOr64,
floatValue: (*state).constFloat64,
intValue: (*state).constInt64,
cutoff: 9223372036854775808,
}
var f32_u32 f2uCvtTab = f2uCvtTab{
ltf: ssa.OpLess32F,
cvt2U: ssa.OpCvt32Fto32,
subf: ssa.OpSub32F,
or: ssa.OpOr32,
floatValue: (*state).constFloat32,
intValue: func(s *state, t ssa.Type, v int64) *ssa.Value { return s.constInt32(t, int32(v)) },
cutoff: 2147483648,
}
var f64_u32 f2uCvtTab = f2uCvtTab{
ltf: ssa.OpLess64F,
cvt2U: ssa.OpCvt64Fto32,
subf: ssa.OpSub64F,
or: ssa.OpOr32,
floatValue: (*state).constFloat64,
intValue: func(s *state, t ssa.Type, v int64) *ssa.Value { return s.constInt32(t, int32(v)) },
cutoff: 2147483648,
}
func (s *state) float32ToUint64(n *Node, x *ssa.Value, ft, tt *Type) *ssa.Value {
return s.floatToUint(&f32_u64, n, x, ft, tt)
}
func (s *state) float64ToUint64(n *Node, x *ssa.Value, ft, tt *Type) *ssa.Value {
return s.floatToUint(&f64_u64, n, x, ft, tt)
}
func (s *state) float32ToUint32(n *Node, x *ssa.Value, ft, tt *Type) *ssa.Value {
return s.floatToUint(&f32_u32, n, x, ft, tt)
}
func (s *state) float64ToUint32(n *Node, x *ssa.Value, ft, tt *Type) *ssa.Value {
return s.floatToUint(&f64_u32, n, x, ft, tt)
}
func (s *state) floatToUint(cvttab *f2uCvtTab, n *Node, x *ssa.Value, ft, tt *Type) *ssa.Value {
// cutoff:=1<<(intY_Size-1)
// if x < floatX(cutoff) {
// result = uintY(x)
// } else {
// y = x - floatX(cutoff)
// z = uintY(y)
// result = z | -(cutoff)
// }
cutoff := cvttab.floatValue(s, ft, float64(cvttab.cutoff))
cmp := s.newValue2(cvttab.ltf, Types[TBOOL], x, cutoff)
b := s.endBlock()
b.Kind = ssa.BlockIf
b.SetControl(cmp)
b.Likely = ssa.BranchLikely
bThen := s.f.NewBlock(ssa.BlockPlain)
bElse := s.f.NewBlock(ssa.BlockPlain)
bAfter := s.f.NewBlock(ssa.BlockPlain)
b.AddEdgeTo(bThen)
s.startBlock(bThen)
a0 := s.newValue1(cvttab.cvt2U, tt, x)
s.vars[n] = a0
s.endBlock()
bThen.AddEdgeTo(bAfter)
b.AddEdgeTo(bElse)
s.startBlock(bElse)
y := s.newValue2(cvttab.subf, ft, x, cutoff)
y = s.newValue1(cvttab.cvt2U, tt, y)
z := cvttab.intValue(s, tt, int64(-cvttab.cutoff))
a1 := s.newValue2(cvttab.or, tt, y, z)
s.vars[n] = a1
s.endBlock()
bElse.AddEdgeTo(bAfter)
s.startBlock(bAfter)
return s.variable(n, n.Type)
}
// dottype generates SSA for a type assertion node.
// commaok indicates whether to panic or return a bool.
// If commaok is false, resok will be nil.
func (s *state) dottype(n *Node, commaok bool) (res, resok *ssa.Value) {
iface := s.expr(n.Left) // input interface
target := s.expr(typename(n.Type)) // target type
byteptr := ptrto(Types[TUINT8])
if n.Type.IsInterface() {
if n.Type.IsEmptyInterface() {
// Converting to an empty interface.
// Input could be an empty or nonempty interface.
if Debug_typeassert > 0 {
Warnl(n.Pos, "type assertion inlined")
}
// Get itab/type field from input.
itab := s.newValue1(ssa.OpITab, byteptr, iface)
// Conversion succeeds iff that field is not nil.
cond := s.newValue2(ssa.OpNeqPtr, Types[TBOOL], itab, s.constNil(byteptr))
if n.Left.Type.IsEmptyInterface() && commaok {
// Converting empty interface to empty interface with ,ok is just a nil check.
return iface, cond
}
// Branch on nilness.
b := s.endBlock()
b.Kind = ssa.BlockIf
b.SetControl(cond)
b.Likely = ssa.BranchLikely
bOk := s.f.NewBlock(ssa.BlockPlain)
bFail := s.f.NewBlock(ssa.BlockPlain)
b.AddEdgeTo(bOk)
b.AddEdgeTo(bFail)
if !commaok {
// On failure, panic by calling panicnildottype.
s.startBlock(bFail)
s.rtcall(panicnildottype, false, nil, target)
// On success, return (perhaps modified) input interface.
s.startBlock(bOk)
if n.Left.Type.IsEmptyInterface() {
res = iface // Use input interface unchanged.
return
}
// Load type out of itab, build interface with existing idata.
off := s.newValue1I(ssa.OpOffPtr, byteptr, int64(Widthptr), itab)
typ := s.newValue2(ssa.OpLoad, byteptr, off, s.mem())
idata := s.newValue1(ssa.OpIData, n.Type, iface)
res = s.newValue2(ssa.OpIMake, n.Type, typ, idata)
return
}
s.startBlock(bOk)
// nonempty -> empty
// Need to load type from itab
off := s.newValue1I(ssa.OpOffPtr, byteptr, int64(Widthptr), itab)
s.vars[&typVar] = s.newValue2(ssa.OpLoad, byteptr, off, s.mem())
s.endBlock()
// itab is nil, might as well use that as the nil result.
s.startBlock(bFail)
s.vars[&typVar] = itab
s.endBlock()
// Merge point.
bEnd := s.f.NewBlock(ssa.BlockPlain)
bOk.AddEdgeTo(bEnd)
bFail.AddEdgeTo(bEnd)
s.startBlock(bEnd)
idata := s.newValue1(ssa.OpIData, n.Type, iface)
res = s.newValue2(ssa.OpIMake, n.Type, s.variable(&typVar, byteptr), idata)
resok = cond
delete(s.vars, &typVar)
return
}
// converting to a nonempty interface needs a runtime call.
if Debug_typeassert > 0 {
Warnl(n.Pos, "type assertion not inlined")
}
if n.Left.Type.IsEmptyInterface() {
if commaok {
call := s.rtcall(assertE2I2, true, []*Type{n.Type, Types[TBOOL]}, target, iface)
return call[0], call[1]
}
return s.rtcall(assertE2I, true, []*Type{n.Type}, target, iface)[0], nil
}
if commaok {
call := s.rtcall(assertI2I2, true, []*Type{n.Type, Types[TBOOL]}, target, iface)
return call[0], call[1]
}
return s.rtcall(assertI2I, true, []*Type{n.Type}, target, iface)[0], nil
}
if Debug_typeassert > 0 {
Warnl(n.Pos, "type assertion inlined")
}
// Converting to a concrete type.
direct := isdirectiface(n.Type)
itab := s.newValue1(ssa.OpITab, byteptr, iface) // type word of interface
if Debug_typeassert > 0 {
Warnl(n.Pos, "type assertion inlined")
}
var targetITab *ssa.Value
if n.Left.Type.IsEmptyInterface() {
// Looking for pointer to target type.
targetITab = target
} else {
// Looking for pointer to itab for target type and source interface.
targetITab = s.expr(itabname(n.Type, n.Left.Type))
}
var tmp *Node // temporary for use with large types
var addr *ssa.Value // address of tmp
if commaok && !canSSAType(n.Type) {
// unSSAable type, use temporary.
// TODO: get rid of some of these temporaries.
tmp = temp(n.Type)
addr, _ = s.addr(tmp, false)
s.vars[&memVar] = s.newValue1A(ssa.OpVarDef, ssa.TypeMem, tmp, s.mem())
}
cond := s.newValue2(ssa.OpEqPtr, Types[TBOOL], itab, targetITab)
b := s.endBlock()
b.Kind = ssa.BlockIf
b.SetControl(cond)
b.Likely = ssa.BranchLikely
bOk := s.f.NewBlock(ssa.BlockPlain)
bFail := s.f.NewBlock(ssa.BlockPlain)
b.AddEdgeTo(bOk)
b.AddEdgeTo(bFail)
if !commaok {
// on failure, panic by calling panicdottype
s.startBlock(bFail)
taddr := s.newValue1A(ssa.OpAddr, byteptr, &ssa.ExternSymbol{Typ: byteptr, Sym: Linksym(typenamesym(n.Left.Type))}, s.sb)
if n.Left.Type.IsEmptyInterface() {
s.rtcall(panicdottypeE, false, nil, itab, target, taddr)
} else {
s.rtcall(panicdottypeI, false, nil, itab, target, taddr)
}
// on success, return data from interface
s.startBlock(bOk)
if direct {
return s.newValue1(ssa.OpIData, n.Type, iface), nil
}
p := s.newValue1(ssa.OpIData, ptrto(n.Type), iface)
return s.newValue2(ssa.OpLoad, n.Type, p, s.mem()), nil
}
// commaok is the more complicated case because we have
// a control flow merge point.
bEnd := s.f.NewBlock(ssa.BlockPlain)
// Note that we need a new valVar each time (unlike okVar where we can
// reuse the variable) because it might have a different type every time.
valVar := &Node{Op: ONAME, Class: Pxxx, Sym: &Sym{Name: "val"}}
// type assertion succeeded
s.startBlock(bOk)
if tmp == nil {
if direct {
s.vars[valVar] = s.newValue1(ssa.OpIData, n.Type, iface)
} else {
p := s.newValue1(ssa.OpIData, ptrto(n.Type), iface)
s.vars[valVar] = s.newValue2(ssa.OpLoad, n.Type, p, s.mem())
}
} else {
p := s.newValue1(ssa.OpIData, ptrto(n.Type), iface)
s.vars[&memVar] = s.newValue3I(ssa.OpMove, ssa.TypeMem, sizeAlignAuxInt(n.Type), addr, p, s.mem())
}
s.vars[&okVar] = s.constBool(true)
s.endBlock()
bOk.AddEdgeTo(bEnd)
// type assertion failed
s.startBlock(bFail)
if tmp == nil {
s.vars[valVar] = s.zeroVal(n.Type)
} else {
s.vars[&memVar] = s.newValue2I(ssa.OpZero, ssa.TypeMem, sizeAlignAuxInt(n.Type), addr, s.mem())
}
s.vars[&okVar] = s.constBool(false)
s.endBlock()
bFail.AddEdgeTo(bEnd)
// merge point
s.startBlock(bEnd)
if tmp == nil {
res = s.variable(valVar, n.Type)
delete(s.vars, valVar)
} else {
res = s.newValue2(ssa.OpLoad, n.Type, addr, s.mem())
s.vars[&memVar] = s.newValue1A(ssa.OpVarKill, ssa.TypeMem, tmp, s.mem())
}
resok = s.variable(&okVar, Types[TBOOL])
delete(s.vars, &okVar)
return res, resok
}
// checkgoto checks that a goto from from to to does not
// jump into a block or jump over variable declarations.
func (s *state) checkgoto(from *Node, to *Node) {
if from.Op != OGOTO || to.Op != OLABEL {
Fatalf("bad from/to in checkgoto: %v -> %v", from, to)
}
// from and to's Sym fields record dclstack's value at their
// position, which implicitly encodes their block nesting
// level and variable declaration position within that block.
//
// For valid gotos, to.Sym will be a tail of from.Sym.
// Otherwise, any link in to.Sym not also in from.Sym
// indicates a block/declaration being jumped into/over.
//
// TODO(mdempsky): We should only complain about jumping over
// variable declarations, but currently we reject type and
// constant declarations too (#8042).
if from.Sym == to.Sym {
return
}
nf := dcldepth(from.Sym)
nt := dcldepth(to.Sym)
// Unwind from.Sym so it's no longer than to.Sym. It's okay to
// jump out of blocks or backwards past variable declarations.
fs := from.Sym
for ; nf > nt; nf-- {
fs = fs.Link
}
if fs == to.Sym {
return
}
// Decide what to complain about. Unwind to.Sym until where it
// forked from from.Sym, and keep track of the innermost block
// and declaration we jumped into/over.
var block *Sym
var dcl *Sym
// If to.Sym is longer, unwind until it's the same length.
ts := to.Sym
for ; nt > nf; nt-- {
if ts.Pkg == nil {
block = ts
} else {
dcl = ts
}
ts = ts.Link
}
// Same length; unwind until we find their common ancestor.
for ts != fs {
if ts.Pkg == nil {
block = ts
} else {
dcl = ts
}
ts = ts.Link
fs = fs.Link
}
// Prefer to complain about 'into block' over declarations.
lno := from.Left.Pos
if block != nil {
yyerrorl(lno, "goto %v jumps into block starting at %v", from.Left.Sym, linestr(block.Lastlineno))
} else {
yyerrorl(lno, "goto %v jumps over declaration of %v at %v", from.Left.Sym, dcl, linestr(dcl.Lastlineno))
}
}
// dcldepth returns the declaration depth for a dclstack Sym; that is,
// the sum of the block nesting level and the number of declarations
// in scope.
func dcldepth(s *Sym) int {
n := 0
for ; s != nil; s = s.Link {
n++
}
return n
}
// variable returns the value of a variable at the current location.
func (s *state) variable(name *Node, t ssa.Type) *ssa.Value {
v := s.vars[name]
if v != nil {
return v
}
v = s.fwdVars[name]
if v != nil {
return v
}
if s.curBlock == s.f.Entry {
// No variable should be live at entry.
s.Fatalf("Value live at entry. It shouldn't be. func %s, node %v, value %v", s.f.Name, name, v)
}
// Make a FwdRef, which records a value that's live on block input.
// We'll find the matching definition as part of insertPhis.
v = s.newValue0A(ssa.OpFwdRef, t, name)
s.fwdVars[name] = v
s.addNamedValue(name, v)
return v
}
func (s *state) mem() *ssa.Value {
return s.variable(&memVar, ssa.TypeMem)
}
func (s *state) addNamedValue(n *Node, v *ssa.Value) {
if n.Class == Pxxx {
// Don't track our dummy nodes (&memVar etc.).
return
}
if n.IsAutoTmp() {
// Don't track temporary variables.
return
}
if n.Class == PPARAMOUT {
// Don't track named output values. This prevents return values
// from being assigned too early. See #14591 and #14762. TODO: allow this.
return
}
if n.Class == PAUTO && n.Xoffset != 0 {
s.Fatalf("AUTO var with offset %v %d", n, n.Xoffset)
}
loc := ssa.LocalSlot{N: n, Type: n.Type, Off: 0}
values, ok := s.f.NamedValues[loc]
if !ok {
s.f.Names = append(s.f.Names, loc)
}
s.f.NamedValues[loc] = append(values, v)
}
// Branch is an unresolved branch.
type Branch struct {
P *obj.Prog // branch instruction
B *ssa.Block // target
}
// SSAGenState contains state needed during Prog generation.
type SSAGenState struct {
// Branches remembers all the branch instructions we've seen
// and where they would like to go.
Branches []Branch
// bstart remembers where each block starts (indexed by block ID)
bstart []*obj.Prog
// 387 port: maps from SSE registers (REG_X?) to 387 registers (REG_F?)
SSEto387 map[int16]int16
// Some architectures require a 64-bit temporary for FP-related register shuffling. Examples include x86-387, PPC, and Sparc V8.
ScratchFpMem *Node
}
// Pc returns the current Prog.
func (s *SSAGenState) Pc() *obj.Prog {
return pc
}
// SetPos sets the current source position.
func (s *SSAGenState) SetPos(pos src.XPos) {
lineno = pos
}
// genssa appends entries to ptxt for each instruction in f.
// gcargs and gclocals are filled in with pointer maps for the frame.
func genssa(f *ssa.Func, ptxt *obj.Prog, gcargs, gclocals *Sym) {
var s SSAGenState
e := f.Config.Frontend().(*ssaExport)
// Remember where each block starts.
s.bstart = make([]*obj.Prog, f.NumBlocks())
var valueProgs map[*obj.Prog]*ssa.Value
var blockProgs map[*obj.Prog]*ssa.Block
var logProgs = e.log
if logProgs {
valueProgs = make(map[*obj.Prog]*ssa.Value, f.NumValues())
blockProgs = make(map[*obj.Prog]*ssa.Block, f.NumBlocks())
f.Logf("genssa %s\n", f.Name)
blockProgs[pc] = f.Blocks[0]
}
if Thearch.Use387 {
s.SSEto387 = map[int16]int16{}
}
s.ScratchFpMem = scratchFpMem
scratchFpMem = nil
// Emit basic blocks
for i, b := range f.Blocks {
s.bstart[b.ID] = pc
// Emit values in block
Thearch.SSAMarkMoves(&s, b)
for _, v := range b.Values {
x := pc
Thearch.SSAGenValue(&s, v)
if logProgs {
for ; x != pc; x = x.Link {
valueProgs[x] = v
}
}
}
// Emit control flow instructions for block
var next *ssa.Block
if i < len(f.Blocks)-1 && Debug['N'] == 0 {
// If -N, leave next==nil so every block with successors
// ends in a JMP (except call blocks - plive doesn't like
// select{send,recv} followed by a JMP call). Helps keep
// line numbers for otherwise empty blocks.
next = f.Blocks[i+1]
}
x := pc
Thearch.SSAGenBlock(&s, b, next)
if logProgs {
for ; x != pc; x = x.Link {
blockProgs[x] = b
}
}
}
// Resolve branches
for _, br := range s.Branches {
br.P.To.Val = s.bstart[br.B.ID]
}
if logProgs {
for p := ptxt; p != nil; p = p.Link {
var s string
if v, ok := valueProgs[p]; ok {
s = v.String()
} else if b, ok := blockProgs[p]; ok {
s = b.String()
} else {
s = " " // most value and branch strings are 2-3 characters long
}
f.Logf("%s\t%s\n", s, p)
}
if f.Config.HTML != nil {
// LineHist is defunct now - this code won't do
// anything.
// TODO: fix this (ideally without a global variable)
// saved := ptxt.Ctxt.LineHist.PrintFilenameOnly
// ptxt.Ctxt.LineHist.PrintFilenameOnly = true
var buf bytes.Buffer
buf.WriteString("<code>")
buf.WriteString("<dl class=\"ssa-gen\">")
for p := ptxt; p != nil; p = p.Link {
buf.WriteString("<dt class=\"ssa-prog-src\">")
if v, ok := valueProgs[p]; ok {
buf.WriteString(v.HTML())
} else if b, ok := blockProgs[p]; ok {
buf.WriteString(b.HTML())
}
buf.WriteString("</dt>")
buf.WriteString("<dd class=\"ssa-prog\">")
buf.WriteString(html.EscapeString(p.String()))
buf.WriteString("</dd>")
buf.WriteString("</li>")
}
buf.WriteString("</dl>")
buf.WriteString("</code>")
f.Config.HTML.WriteColumn("genssa", buf.String())
// ptxt.Ctxt.LineHist.PrintFilenameOnly = saved
}
}
// Generate gc bitmaps.
liveness(Curfn, ptxt, gcargs, gclocals)
// Add frame prologue. Zero ambiguously live variables.
Thearch.Defframe(ptxt)
if Debug['f'] != 0 {
frame(0)
}
// Remove leftover instrumentation from the instruction stream.
removevardef(ptxt)
f.Config.HTML.Close()
f.Config.HTML = nil
}
type FloatingEQNEJump struct {
Jump obj.As
Index int
}
func oneFPJump(b *ssa.Block, jumps *FloatingEQNEJump, likely ssa.BranchPrediction, branches []Branch) []Branch {
p := Prog(jumps.Jump)
p.To.Type = obj.TYPE_BRANCH
to := jumps.Index
branches = append(branches, Branch{p, b.Succs[to].Block()})
if to == 1 {
likely = -likely
}
// liblink reorders the instruction stream as it sees fit.
// Pass along what we know so liblink can make use of it.
// TODO: Once we've fully switched to SSA,
// make liblink leave our output alone.
switch likely {
case ssa.BranchUnlikely:
p.From.Type = obj.TYPE_CONST
p.From.Offset = 0
case ssa.BranchLikely:
p.From.Type = obj.TYPE_CONST
p.From.Offset = 1
}
return branches
}
func SSAGenFPJump(s *SSAGenState, b, next *ssa.Block, jumps *[2][2]FloatingEQNEJump) {
likely := b.Likely
switch next {
case b.Succs[0].Block():
s.Branches = oneFPJump(b, &jumps[0][0], likely, s.Branches)
s.Branches = oneFPJump(b, &jumps[0][1], likely, s.Branches)
case b.Succs[1].Block():
s.Branches = oneFPJump(b, &jumps[1][0], likely, s.Branches)
s.Branches = oneFPJump(b, &jumps[1][1], likely, s.Branches)
default:
s.Branches = oneFPJump(b, &jumps[1][0], likely, s.Branches)
s.Branches = oneFPJump(b, &jumps[1][1], likely, s.Branches)
q := Prog(obj.AJMP)
q.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, Branch{q, b.Succs[1].Block()})
}
}
func AuxOffset(v *ssa.Value) (offset int64) {
if v.Aux == nil {
return 0
}
switch sym := v.Aux.(type) {
case *ssa.AutoSymbol:
n := sym.Node.(*Node)
return n.Xoffset
}
return 0
}
// AddAux adds the offset in the aux fields (AuxInt and Aux) of v to a.
func AddAux(a *obj.Addr, v *ssa.Value) {
AddAux2(a, v, v.AuxInt)
}
func AddAux2(a *obj.Addr, v *ssa.Value, offset int64) {
if a.Type != obj.TYPE_MEM && a.Type != obj.TYPE_ADDR {
v.Fatalf("bad AddAux addr %v", a)
}
// add integer offset
a.Offset += offset
// If no additional symbol offset, we're done.
if v.Aux == nil {
return
}
// Add symbol's offset from its base register.
switch sym := v.Aux.(type) {
case *ssa.ExternSymbol:
a.Name = obj.NAME_EXTERN
a.Sym = sym.Sym
case *ssa.ArgSymbol:
n := sym.Node.(*Node)
a.Name = obj.NAME_PARAM
a.Node = n
a.Sym = Linksym(n.Orig.Sym)
a.Offset += n.Xoffset
case *ssa.AutoSymbol:
n := sym.Node.(*Node)
a.Name = obj.NAME_AUTO
a.Node = n
a.Sym = Linksym(n.Sym)
a.Offset += n.Xoffset
default:
v.Fatalf("aux in %s not implemented %#v", v, v.Aux)
}
}
// sizeAlignAuxInt returns an AuxInt encoding the size and alignment of type t.
func sizeAlignAuxInt(t *Type) int64 {
return ssa.MakeSizeAndAlign(t.Size(), t.Alignment()).Int64()
}
// extendIndex extends v to a full int width.
// panic using the given function if v does not fit in an int (only on 32-bit archs).
func (s *state) extendIndex(v *ssa.Value, panicfn *obj.LSym) *ssa.Value {
size := v.Type.Size()
if size == s.config.IntSize {
return v
}
if size > s.config.IntSize {
// truncate 64-bit indexes on 32-bit pointer archs. Test the
// high word and branch to out-of-bounds failure if it is not 0.
if Debug['B'] == 0 {
hi := s.newValue1(ssa.OpInt64Hi, Types[TUINT32], v)
cmp := s.newValue2(ssa.OpEq32, Types[TBOOL], hi, s.constInt32(Types[TUINT32], 0))
s.check(cmp, panicfn)
}
return s.newValue1(ssa.OpTrunc64to32, Types[TINT], v)
}
// Extend value to the required size
var op ssa.Op
if v.Type.IsSigned() {
switch 10*size + s.config.IntSize {
case 14:
op = ssa.OpSignExt8to32
case 18:
op = ssa.OpSignExt8to64
case 24:
op = ssa.OpSignExt16to32
case 28:
op = ssa.OpSignExt16to64
case 48:
op = ssa.OpSignExt32to64
default:
s.Fatalf("bad signed index extension %s", v.Type)
}
} else {
switch 10*size + s.config.IntSize {
case 14:
op = ssa.OpZeroExt8to32
case 18:
op = ssa.OpZeroExt8to64
case 24:
op = ssa.OpZeroExt16to32
case 28:
op = ssa.OpZeroExt16to64
case 48:
op = ssa.OpZeroExt32to64
default:
s.Fatalf("bad unsigned index extension %s", v.Type)
}
}
return s.newValue1(op, Types[TINT], v)
}
// CheckLoweredPhi checks that regalloc and stackalloc correctly handled phi values.
// Called during ssaGenValue.
func CheckLoweredPhi(v *ssa.Value) {
if v.Op != ssa.OpPhi {
v.Fatalf("CheckLoweredPhi called with non-phi value: %v", v.LongString())
}
if v.Type.IsMemory() {
return
}
f := v.Block.Func
loc := f.RegAlloc[v.ID]
for _, a := range v.Args {
if aloc := f.RegAlloc[a.ID]; aloc != loc { // TODO: .Equal() instead?
v.Fatalf("phi arg at different location than phi: %v @ %v, but arg %v @ %v\n%s\n", v, loc, a, aloc, v.Block.Func)
}
}
}
// CheckLoweredGetClosurePtr checks that v is the first instruction in the function's entry block.
// The output of LoweredGetClosurePtr is generally hardwired to the correct register.
// That register contains the closure pointer on closure entry.
func CheckLoweredGetClosurePtr(v *ssa.Value) {
entry := v.Block.Func.Entry
if entry != v.Block || entry.Values[0] != v {
Fatalf("in %s, badly placed LoweredGetClosurePtr: %v %v", v.Block.Func.Name, v.Block, v)
}
}
// KeepAlive marks the variable referenced by OpKeepAlive as live.
// Called during ssaGenValue.
func KeepAlive(v *ssa.Value) {
if v.Op != ssa.OpKeepAlive {
v.Fatalf("KeepAlive called with non-KeepAlive value: %v", v.LongString())
}
if !v.Args[0].Type.IsPtrShaped() {
v.Fatalf("keeping non-pointer alive %v", v.Args[0])
}
n, _ := AutoVar(v.Args[0])
if n == nil {
v.Fatalf("KeepAlive with non-spilled value %s %s", v, v.Args[0])
}
// Note: KeepAlive arg may be a small part of a larger variable n. We keep the
// whole variable n alive at this point. (Typically, this happens when
// we are requested to keep the idata portion of an interface{} alive, and
// we end up keeping the whole interface{} alive. That's ok.)
Gvarlive(n)
}
// AutoVar returns a *Node and int64 representing the auto variable and offset within it
// where v should be spilled.
func AutoVar(v *ssa.Value) (*Node, int64) {
loc := v.Block.Func.RegAlloc[v.ID].(ssa.LocalSlot)
if v.Type.Size() > loc.Type.Size() {
v.Fatalf("spill/restore type %s doesn't fit in slot type %s", v.Type, loc.Type)
}
return loc.N.(*Node), loc.Off
}
func AddrAuto(a *obj.Addr, v *ssa.Value) {
n, off := AutoVar(v)
a.Type = obj.TYPE_MEM
a.Node = n
a.Sym = Linksym(n.Sym)
a.Offset = n.Xoffset + off
if n.Class == PPARAM || n.Class == PPARAMOUT {
a.Name = obj.NAME_PARAM
} else {
a.Name = obj.NAME_AUTO
}
}
func (s *SSAGenState) AddrScratch(a *obj.Addr) {
if s.ScratchFpMem == nil {
panic("no scratch memory available; forgot to declare usesScratch for Op?")
}
a.Type = obj.TYPE_MEM
a.Name = obj.NAME_AUTO
a.Node = s.ScratchFpMem
a.Sym = Linksym(s.ScratchFpMem.Sym)
a.Reg = int16(Thearch.REGSP)
a.Offset = s.ScratchFpMem.Xoffset
}
// fieldIdx finds the index of the field referred to by the ODOT node n.
func fieldIdx(n *Node) int {
t := n.Left.Type
f := n.Sym
if !t.IsStruct() {
panic("ODOT's LHS is not a struct")
}
var i int
for _, t1 := range t.Fields().Slice() {
if t1.Sym != f {
i++
continue
}
if t1.Offset != n.Xoffset {
panic("field offset doesn't match")
}
return i
}
panic(fmt.Sprintf("can't find field in expr %v\n", n))
// TODO: keep the result of this function somewhere in the ODOT Node
// so we don't have to recompute it each time we need it.
}
// ssaExport exports a bunch of compiler services for the ssa backend.
type ssaExport struct {
log bool
}
func (s *ssaExport) TypeBool() ssa.Type { return Types[TBOOL] }
func (s *ssaExport) TypeInt8() ssa.Type { return Types[TINT8] }
func (s *ssaExport) TypeInt16() ssa.Type { return Types[TINT16] }
func (s *ssaExport) TypeInt32() ssa.Type { return Types[TINT32] }
func (s *ssaExport) TypeInt64() ssa.Type { return Types[TINT64] }
func (s *ssaExport) TypeUInt8() ssa.Type { return Types[TUINT8] }
func (s *ssaExport) TypeUInt16() ssa.Type { return Types[TUINT16] }
func (s *ssaExport) TypeUInt32() ssa.Type { return Types[TUINT32] }
func (s *ssaExport) TypeUInt64() ssa.Type { return Types[TUINT64] }
func (s *ssaExport) TypeFloat32() ssa.Type { return Types[TFLOAT32] }
func (s *ssaExport) TypeFloat64() ssa.Type { return Types[TFLOAT64] }
func (s *ssaExport) TypeInt() ssa.Type { return Types[TINT] }
func (s *ssaExport) TypeUintptr() ssa.Type { return Types[TUINTPTR] }
func (s *ssaExport) TypeString() ssa.Type { return Types[TSTRING] }
func (s *ssaExport) TypeBytePtr() ssa.Type { return ptrto(Types[TUINT8]) }
// StringData returns a symbol (a *Sym wrapped in an interface) which
// is the data component of a global string constant containing s.
func (*ssaExport) StringData(s string) interface{} {
// TODO: is idealstring correct? It might not matter...
data := stringsym(s)
return &ssa.ExternSymbol{Typ: idealstring, Sym: data}
}
func (e *ssaExport) Auto(t ssa.Type) ssa.GCNode {
n := temp(t.(*Type)) // Note: adds new auto to Curfn.Func.Dcl list
return n
}
func (e *ssaExport) SplitString(name ssa.LocalSlot) (ssa.LocalSlot, ssa.LocalSlot) {
n := name.N.(*Node)
ptrType := ptrto(Types[TUINT8])
lenType := Types[TINT]
if n.Class == PAUTO && !n.Addrtaken {
// Split this string up into two separate variables.
p := e.namedAuto(n.Sym.Name+".ptr", ptrType)
l := e.namedAuto(n.Sym.Name+".len", lenType)
return ssa.LocalSlot{N: p, Type: ptrType, Off: 0}, ssa.LocalSlot{N: l, Type: lenType, Off: 0}
}
// Return the two parts of the larger variable.
return ssa.LocalSlot{N: n, Type: ptrType, Off: name.Off}, ssa.LocalSlot{N: n, Type: lenType, Off: name.Off + int64(Widthptr)}
}
func (e *ssaExport) SplitInterface(name ssa.LocalSlot) (ssa.LocalSlot, ssa.LocalSlot) {
n := name.N.(*Node)
t := ptrto(Types[TUINT8])
if n.Class == PAUTO && !n.Addrtaken {
// Split this interface up into two separate variables.
f := ".itab"
if n.Type.IsEmptyInterface() {
f = ".type"
}
c := e.namedAuto(n.Sym.Name+f, t)
d := e.namedAuto(n.Sym.Name+".data", t)
return ssa.LocalSlot{N: c, Type: t, Off: 0}, ssa.LocalSlot{N: d, Type: t, Off: 0}
}
// Return the two parts of the larger variable.
return ssa.LocalSlot{N: n, Type: t, Off: name.Off}, ssa.LocalSlot{N: n, Type: t, Off: name.Off + int64(Widthptr)}
}
func (e *ssaExport) SplitSlice(name ssa.LocalSlot) (ssa.LocalSlot, ssa.LocalSlot, ssa.LocalSlot) {
n := name.N.(*Node)
ptrType := ptrto(name.Type.ElemType().(*Type))
lenType := Types[TINT]
if n.Class == PAUTO && !n.Addrtaken {
// Split this slice up into three separate variables.
p := e.namedAuto(n.Sym.Name+".ptr", ptrType)
l := e.namedAuto(n.Sym.Name+".len", lenType)
c := e.namedAuto(n.Sym.Name+".cap", lenType)
return ssa.LocalSlot{N: p, Type: ptrType, Off: 0}, ssa.LocalSlot{N: l, Type: lenType, Off: 0}, ssa.LocalSlot{N: c, Type: lenType, Off: 0}
}
// Return the three parts of the larger variable.
return ssa.LocalSlot{N: n, Type: ptrType, Off: name.Off},
ssa.LocalSlot{N: n, Type: lenType, Off: name.Off + int64(Widthptr)},
ssa.LocalSlot{N: n, Type: lenType, Off: name.Off + int64(2*Widthptr)}
}
func (e *ssaExport) SplitComplex(name ssa.LocalSlot) (ssa.LocalSlot, ssa.LocalSlot) {
n := name.N.(*Node)
s := name.Type.Size() / 2
var t *Type
if s == 8 {
t = Types[TFLOAT64]
} else {
t = Types[TFLOAT32]
}
if n.Class == PAUTO && !n.Addrtaken {
// Split this complex up into two separate variables.
c := e.namedAuto(n.Sym.Name+".real", t)
d := e.namedAuto(n.Sym.Name+".imag", t)
return ssa.LocalSlot{N: c, Type: t, Off: 0}, ssa.LocalSlot{N: d, Type: t, Off: 0}
}
// Return the two parts of the larger variable.
return ssa.LocalSlot{N: n, Type: t, Off: name.Off}, ssa.LocalSlot{N: n, Type: t, Off: name.Off + s}
}
func (e *ssaExport) SplitInt64(name ssa.LocalSlot) (ssa.LocalSlot, ssa.LocalSlot) {
n := name.N.(*Node)
var t *Type
if name.Type.IsSigned() {
t = Types[TINT32]
} else {
t = Types[TUINT32]
}
if n.Class == PAUTO && !n.Addrtaken {
// Split this int64 up into two separate variables.
h := e.namedAuto(n.Sym.Name+".hi", t)
l := e.namedAuto(n.Sym.Name+".lo", Types[TUINT32])
return ssa.LocalSlot{N: h, Type: t, Off: 0}, ssa.LocalSlot{N: l, Type: Types[TUINT32], Off: 0}
}
// Return the two parts of the larger variable.
if Thearch.LinkArch.ByteOrder == binary.BigEndian {
return ssa.LocalSlot{N: n, Type: t, Off: name.Off}, ssa.LocalSlot{N: n, Type: Types[TUINT32], Off: name.Off + 4}
}
return ssa.LocalSlot{N: n, Type: t, Off: name.Off + 4}, ssa.LocalSlot{N: n, Type: Types[TUINT32], Off: name.Off}
}
func (e *ssaExport) SplitStruct(name ssa.LocalSlot, i int) ssa.LocalSlot {
n := name.N.(*Node)
st := name.Type
ft := st.FieldType(i)
if n.Class == PAUTO && !n.Addrtaken {
// Note: the _ field may appear several times. But
// have no fear, identically-named but distinct Autos are
// ok, albeit maybe confusing for a debugger.
x := e.namedAuto(n.Sym.Name+"."+st.FieldName(i), ft)
return ssa.LocalSlot{N: x, Type: ft, Off: 0}
}
return ssa.LocalSlot{N: n, Type: ft, Off: name.Off + st.FieldOff(i)}
}
func (e *ssaExport) SplitArray(name ssa.LocalSlot) ssa.LocalSlot {
n := name.N.(*Node)
at := name.Type
if at.NumElem() != 1 {
Fatalf("bad array size")
}
et := at.ElemType()
if n.Class == PAUTO && !n.Addrtaken {
x := e.namedAuto(n.Sym.Name+"[0]", et)
return ssa.LocalSlot{N: x, Type: et, Off: 0}
}
return ssa.LocalSlot{N: n, Type: et, Off: name.Off}
}
// namedAuto returns a new AUTO variable with the given name and type.
// These are exposed to the debugger.
func (e *ssaExport) namedAuto(name string, typ ssa.Type) ssa.GCNode {
t := typ.(*Type)
s := &Sym{Name: name, Pkg: localpkg}
n := nod(ONAME, nil, nil)
s.Def = n
s.Def.Used = true
n.Sym = s
n.Type = t
n.Class = PAUTO
n.Addable = true
n.Ullman = 1
n.Esc = EscNever
n.Xoffset = 0
n.Name.Curfn = Curfn
Curfn.Func.Dcl = append(Curfn.Func.Dcl, n)
dowidth(t)
return n
}
func (e *ssaExport) CanSSA(t ssa.Type) bool {
return canSSAType(t.(*Type))
}
func (e *ssaExport) Line(pos src.XPos) string {
return linestr(pos)
}
// Log logs a message from the compiler.
func (e *ssaExport) Logf(msg string, args ...interface{}) {
if e.log {
fmt.Printf(msg, args...)
}
}
func (e *ssaExport) Log() bool {
return e.log
}
// Fatal reports a compiler error and exits.
func (e *ssaExport) Fatalf(pos src.XPos, msg string, args ...interface{}) {
lineno = pos
Fatalf(msg, args...)
}
// Warnl reports a "warning", which is usually flag-triggered
// logging output for the benefit of tests.
func (e *ssaExport) Warnl(pos src.XPos, fmt_ string, args ...interface{}) {
Warnl(pos, fmt_, args...)
}
func (e *ssaExport) Debug_checknil() bool {
return Debug_checknil != 0
}
func (e *ssaExport) Debug_wb() bool {
return Debug_wb != 0
}
func (e *ssaExport) Syslook(name string) *obj.LSym {
return Linksym(syslook(name).Sym)
}
func (n *Node) Typ() ssa.Type {
return n.Type
}
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