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go/src/cmd/compile/internal/amd64/ssa.go
Ilya Tocar 036d09d5bf cmd/compile/internal/amd64: Use 32-bit operands for byte operations 
We already generate ADDL for byte operations, reflect this in code.
This also allows inc/dec for +-1 operation, which are 1-byte shorter,
and enables lea for 3-operand addition/subtraction.

Change-Id: Ibfdfee50667ca4cd3c28f72e3dece0c6d114d3ae
Reviewed-on: https://go-review.googlesource.com/21251
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-05 15:15:19 +00:00

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// Copyright 2016 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 amd64
import (
"fmt"
"math"
"cmd/compile/internal/gc"
"cmd/compile/internal/ssa"
"cmd/internal/obj"
"cmd/internal/obj/x86"
)
// Smallest possible faulting page at address zero.
const minZeroPage = 4096
// ssaRegToReg maps ssa register numbers to obj register numbers.
var ssaRegToReg = []int16{
x86.REG_AX,
x86.REG_CX,
x86.REG_DX,
x86.REG_BX,
x86.REG_SP,
x86.REG_BP,
x86.REG_SI,
x86.REG_DI,
x86.REG_R8,
x86.REG_R9,
x86.REG_R10,
x86.REG_R11,
x86.REG_R12,
x86.REG_R13,
x86.REG_R14,
x86.REG_R15,
x86.REG_X0,
x86.REG_X1,
x86.REG_X2,
x86.REG_X3,
x86.REG_X4,
x86.REG_X5,
x86.REG_X6,
x86.REG_X7,
x86.REG_X8,
x86.REG_X9,
x86.REG_X10,
x86.REG_X11,
x86.REG_X12,
x86.REG_X13,
x86.REG_X14,
x86.REG_X15,
0, // SB isn't a real register. We fill an Addr.Reg field with 0 in this case.
}
// markMoves marks any MOVXconst ops that need to avoid clobbering flags.
func ssaMarkMoves(s *gc.SSAGenState, b *ssa.Block) {
flive := b.FlagsLiveAtEnd
if b.Control != nil && b.Control.Type.IsFlags() {
flive = true
}
for i := len(b.Values) - 1; i >= 0; i-- {
v := b.Values[i]
if flive && (v.Op == ssa.OpAMD64MOVBconst || v.Op == ssa.OpAMD64MOVWconst || v.Op == ssa.OpAMD64MOVLconst || v.Op == ssa.OpAMD64MOVQconst) {
// The "mark" is any non-nil Aux value.
v.Aux = v
}
if v.Type.IsFlags() {
flive = false
}
for _, a := range v.Args {
if a.Type.IsFlags() {
flive = true
}
}
}
}
// loadByType returns the load instruction of the given type.
func loadByType(t ssa.Type) obj.As {
// Avoid partial register write
if !t.IsFloat() && t.Size() <= 2 {
if t.Size() == 1 {
return x86.AMOVBLZX
} else {
return x86.AMOVWLZX
}
}
// Otherwise, there's no difference between load and store opcodes.
return storeByType(t)
}
// storeByType returns the store instruction of the given type.
func storeByType(t ssa.Type) obj.As {
width := t.Size()
if t.IsFloat() {
switch width {
case 4:
return x86.AMOVSS
case 8:
return x86.AMOVSD
}
} else {
switch width {
case 1:
return x86.AMOVB
case 2:
return x86.AMOVW
case 4:
return x86.AMOVL
case 8:
return x86.AMOVQ
}
}
panic("bad store type")
}
// moveByType returns the reg->reg move instruction of the given type.
func moveByType(t ssa.Type) obj.As {
if t.IsFloat() {
// Moving the whole sse2 register is faster
// than moving just the correct low portion of it.
// There is no xmm->xmm move with 1 byte opcode,
// so use movups, which has 2 byte opcode.
return x86.AMOVUPS
} else {
switch t.Size() {
case 1:
// Avoids partial register write
return x86.AMOVL
case 2:
return x86.AMOVL
case 4:
return x86.AMOVL
case 8:
return x86.AMOVQ
case 16:
return x86.AMOVUPS // int128s are in SSE registers
default:
panic(fmt.Sprintf("bad int register width %d:%s", t.Size(), t))
}
}
panic("bad register type")
}
// opregreg emits instructions for
// dest := dest(To) op src(From)
// and also returns the created obj.Prog so it
// may be further adjusted (offset, scale, etc).
func opregreg(op obj.As, dest, src int16) *obj.Prog {
p := gc.Prog(op)
p.From.Type = obj.TYPE_REG
p.To.Type = obj.TYPE_REG
p.To.Reg = dest
p.From.Reg = src
return p
}
func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
s.SetLineno(v.Line)
switch v.Op {
case ssa.OpAMD64ADDQ, ssa.OpAMD64ADDL, ssa.OpAMD64ADDW, ssa.OpAMD64ADDB:
r := gc.SSARegNum(v)
r1 := gc.SSARegNum(v.Args[0])
r2 := gc.SSARegNum(v.Args[1])
switch {
case r == r1:
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_REG
p.From.Reg = r2
p.To.Type = obj.TYPE_REG
p.To.Reg = r
case r == r2:
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_REG
p.From.Reg = r1
p.To.Type = obj.TYPE_REG
p.To.Reg = r
default:
var asm obj.As
if v.Op == ssa.OpAMD64ADDQ {
asm = x86.ALEAQ
} else {
asm = x86.ALEAL
}
p := gc.Prog(asm)
p.From.Type = obj.TYPE_MEM
p.From.Reg = r1
p.From.Scale = 1
p.From.Index = r2
p.To.Type = obj.TYPE_REG
p.To.Reg = r
}
// 2-address opcode arithmetic, symmetric
case ssa.OpAMD64ADDSS, ssa.OpAMD64ADDSD,
ssa.OpAMD64ANDQ, ssa.OpAMD64ANDL, ssa.OpAMD64ANDW, ssa.OpAMD64ANDB,
ssa.OpAMD64ORQ, ssa.OpAMD64ORL, ssa.OpAMD64ORW, ssa.OpAMD64ORB,
ssa.OpAMD64XORQ, ssa.OpAMD64XORL, ssa.OpAMD64XORW, ssa.OpAMD64XORB,
ssa.OpAMD64MULQ, ssa.OpAMD64MULL, ssa.OpAMD64MULW, ssa.OpAMD64MULB,
ssa.OpAMD64MULSS, ssa.OpAMD64MULSD, ssa.OpAMD64PXOR:
r := gc.SSARegNum(v)
x := gc.SSARegNum(v.Args[0])
y := gc.SSARegNum(v.Args[1])
if x != r && y != r {
opregreg(moveByType(v.Type), r, x)
x = r
}
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_REG
p.To.Type = obj.TYPE_REG
p.To.Reg = r
if x == r {
p.From.Reg = y
} else {
p.From.Reg = x
}
// 2-address opcode arithmetic, not symmetric
case ssa.OpAMD64SUBQ, ssa.OpAMD64SUBL, ssa.OpAMD64SUBW, ssa.OpAMD64SUBB:
r := gc.SSARegNum(v)
x := gc.SSARegNum(v.Args[0])
y := gc.SSARegNum(v.Args[1])
var neg bool
if y == r {
// compute -(y-x) instead
x, y = y, x
neg = true
}
if x != r {
opregreg(moveByType(v.Type), r, x)
}
opregreg(v.Op.Asm(), r, y)
if neg {
if v.Op == ssa.OpAMD64SUBQ {
p := gc.Prog(x86.ANEGQ)
p.To.Type = obj.TYPE_REG
p.To.Reg = r
} else { // Avoids partial registers write
p := gc.Prog(x86.ANEGL)
p.To.Type = obj.TYPE_REG
p.To.Reg = r
}
}
case ssa.OpAMD64SUBSS, ssa.OpAMD64SUBSD, ssa.OpAMD64DIVSS, ssa.OpAMD64DIVSD:
r := gc.SSARegNum(v)
x := gc.SSARegNum(v.Args[0])
y := gc.SSARegNum(v.Args[1])
if y == r && x != r {
// r/y := x op r/y, need to preserve x and rewrite to
// r/y := r/y op x15
x15 := int16(x86.REG_X15)
// register move y to x15
// register move x to y
// rename y with x15
opregreg(moveByType(v.Type), x15, y)
opregreg(moveByType(v.Type), r, x)
y = x15
} else if x != r {
opregreg(moveByType(v.Type), r, x)
}
opregreg(v.Op.Asm(), r, y)
case ssa.OpAMD64DIVQ, ssa.OpAMD64DIVL, ssa.OpAMD64DIVW,
ssa.OpAMD64DIVQU, ssa.OpAMD64DIVLU, ssa.OpAMD64DIVWU,
ssa.OpAMD64MODQ, ssa.OpAMD64MODL, ssa.OpAMD64MODW,
ssa.OpAMD64MODQU, ssa.OpAMD64MODLU, ssa.OpAMD64MODWU:
// Arg[0] is already in AX as it's the only register we allow
// and AX is the only output
x := gc.SSARegNum(v.Args[1])
// CPU faults upon signed overflow, which occurs when most
// negative int is divided by -1.
var j *obj.Prog
if v.Op == ssa.OpAMD64DIVQ || v.Op == ssa.OpAMD64DIVL ||
v.Op == ssa.OpAMD64DIVW || v.Op == ssa.OpAMD64MODQ ||
v.Op == ssa.OpAMD64MODL || v.Op == ssa.OpAMD64MODW {
var c *obj.Prog
switch v.Op {
case ssa.OpAMD64DIVQ, ssa.OpAMD64MODQ:
c = gc.Prog(x86.ACMPQ)
j = gc.Prog(x86.AJEQ)
// go ahead and sign extend to save doing it later
gc.Prog(x86.ACQO)
case ssa.OpAMD64DIVL, ssa.OpAMD64MODL:
c = gc.Prog(x86.ACMPL)
j = gc.Prog(x86.AJEQ)
gc.Prog(x86.ACDQ)
case ssa.OpAMD64DIVW, ssa.OpAMD64MODW:
c = gc.Prog(x86.ACMPW)
j = gc.Prog(x86.AJEQ)
gc.Prog(x86.ACWD)
}
c.From.Type = obj.TYPE_REG
c.From.Reg = x
c.To.Type = obj.TYPE_CONST
c.To.Offset = -1
j.To.Type = obj.TYPE_BRANCH
}
// for unsigned ints, we sign extend by setting DX = 0
// signed ints were sign extended above
if v.Op == ssa.OpAMD64DIVQU || v.Op == ssa.OpAMD64MODQU ||
v.Op == ssa.OpAMD64DIVLU || v.Op == ssa.OpAMD64MODLU ||
v.Op == ssa.OpAMD64DIVWU || v.Op == ssa.OpAMD64MODWU {
c := gc.Prog(x86.AXORQ)
c.From.Type = obj.TYPE_REG
c.From.Reg = x86.REG_DX
c.To.Type = obj.TYPE_REG
c.To.Reg = x86.REG_DX
}
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_REG
p.From.Reg = x
// signed division, rest of the check for -1 case
if j != nil {
j2 := gc.Prog(obj.AJMP)
j2.To.Type = obj.TYPE_BRANCH
var n *obj.Prog
if v.Op == ssa.OpAMD64DIVQ || v.Op == ssa.OpAMD64DIVL ||
v.Op == ssa.OpAMD64DIVW {
// n * -1 = -n
n = gc.Prog(x86.ANEGQ)
n.To.Type = obj.TYPE_REG
n.To.Reg = x86.REG_AX
} else {
// n % -1 == 0
n = gc.Prog(x86.AXORQ)
n.From.Type = obj.TYPE_REG
n.From.Reg = x86.REG_DX
n.To.Type = obj.TYPE_REG
n.To.Reg = x86.REG_DX
}
j.To.Val = n
j2.To.Val = s.Pc()
}
case ssa.OpAMD64HMULQ, ssa.OpAMD64HMULL, ssa.OpAMD64HMULW, ssa.OpAMD64HMULB,
ssa.OpAMD64HMULQU, ssa.OpAMD64HMULLU, ssa.OpAMD64HMULWU, ssa.OpAMD64HMULBU:
// the frontend rewrites constant division by 8/16/32 bit integers into
// HMUL by a constant
// SSA rewrites generate the 64 bit versions
// Arg[0] is already in AX as it's the only register we allow
// and DX is the only output we care about (the high bits)
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_REG
p.From.Reg = gc.SSARegNum(v.Args[1])
// IMULB puts the high portion in AH instead of DL,
// so move it to DL for consistency
if v.Type.Size() == 1 {
m := gc.Prog(x86.AMOVB)
m.From.Type = obj.TYPE_REG
m.From.Reg = x86.REG_AH
m.To.Type = obj.TYPE_REG
m.To.Reg = x86.REG_DX
}
case ssa.OpAMD64AVGQU:
// compute (x+y)/2 unsigned.
// Do a 64-bit add, the overflow goes into the carry.
// Shift right once and pull the carry back into the 63rd bit.
r := gc.SSARegNum(v)
x := gc.SSARegNum(v.Args[0])
y := gc.SSARegNum(v.Args[1])
if x != r && y != r {
opregreg(moveByType(v.Type), r, x)
x = r
}
p := gc.Prog(x86.AADDQ)
p.From.Type = obj.TYPE_REG
p.To.Type = obj.TYPE_REG
p.To.Reg = r
if x == r {
p.From.Reg = y
} else {
p.From.Reg = x
}
p = gc.Prog(x86.ARCRQ)
p.From.Type = obj.TYPE_CONST
p.From.Offset = 1
p.To.Type = obj.TYPE_REG
p.To.Reg = r
case ssa.OpAMD64SHLQ, ssa.OpAMD64SHLL, ssa.OpAMD64SHLW, ssa.OpAMD64SHLB,
ssa.OpAMD64SHRQ, ssa.OpAMD64SHRL, ssa.OpAMD64SHRW, ssa.OpAMD64SHRB,
ssa.OpAMD64SARQ, ssa.OpAMD64SARL, ssa.OpAMD64SARW, ssa.OpAMD64SARB:
x := gc.SSARegNum(v.Args[0])
r := gc.SSARegNum(v)
if x != r {
if r == x86.REG_CX {
v.Fatalf("can't implement %s, target and shift both in CX", v.LongString())
}
p := gc.Prog(moveByType(v.Type))
p.From.Type = obj.TYPE_REG
p.From.Reg = x
p.To.Type = obj.TYPE_REG
p.To.Reg = r
}
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_REG
p.From.Reg = gc.SSARegNum(v.Args[1]) // should be CX
p.To.Type = obj.TYPE_REG
p.To.Reg = r
case ssa.OpAMD64ADDQconst, ssa.OpAMD64ADDLconst, ssa.OpAMD64ADDWconst, ssa.OpAMD64ADDBconst:
r := gc.SSARegNum(v)
a := gc.SSARegNum(v.Args[0])
if r == a {
if v.AuxInt == 1 {
var asm obj.As
// Software optimization manual recommends add $1,reg.
// But inc/dec is 1 byte smaller. ICC always uses inc
// Clang/GCC choose depending on flags, but prefer add.
// Experiments show that inc/dec is both a little faster
// and make a binary a little smaller.
if v.Op == ssa.OpAMD64ADDQconst {
asm = x86.AINCQ
} else {
asm = x86.AINCL
}
p := gc.Prog(asm)
p.To.Type = obj.TYPE_REG
p.To.Reg = r
return
} else if v.AuxInt == -1 {
var asm obj.As
if v.Op == ssa.OpAMD64ADDQconst {
asm = x86.ADECQ
} else {
asm = x86.ADECL
}
p := gc.Prog(asm)
p.To.Type = obj.TYPE_REG
p.To.Reg = r
return
} else {
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_CONST
p.From.Offset = v.AuxInt
p.To.Type = obj.TYPE_REG
p.To.Reg = r
return
}
}
var asm obj.As
if v.Op == ssa.OpAMD64ADDQconst {
asm = x86.ALEAQ
} else {
asm = x86.ALEAL
}
p := gc.Prog(asm)
p.From.Type = obj.TYPE_MEM
p.From.Reg = a
p.From.Offset = v.AuxInt
p.To.Type = obj.TYPE_REG
p.To.Reg = r
case ssa.OpAMD64CMOVQEQconst, ssa.OpAMD64CMOVLEQconst, ssa.OpAMD64CMOVWEQconst,
ssa.OpAMD64CMOVQNEconst, ssa.OpAMD64CMOVLNEconst, ssa.OpAMD64CMOVWNEconst:
r := gc.SSARegNum(v)
x := gc.SSARegNum(v.Args[0])
// Arg0 is in/out, move in to out if not already same
if r != x {
p := gc.Prog(moveByType(v.Type))
p.From.Type = obj.TYPE_REG
p.From.Reg = x
p.To.Type = obj.TYPE_REG
p.To.Reg = r
}
// Constant into AX, after arg0 movement in case arg0 is in AX
p := gc.Prog(moveByType(v.Type))
p.From.Type = obj.TYPE_CONST
p.From.Offset = v.AuxInt
p.To.Type = obj.TYPE_REG
p.To.Reg = x86.REG_AX
p = gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_REG
p.From.Reg = x86.REG_AX
p.To.Type = obj.TYPE_REG
p.To.Reg = r
case ssa.OpAMD64MULQconst, ssa.OpAMD64MULLconst, ssa.OpAMD64MULWconst, ssa.OpAMD64MULBconst:
r := gc.SSARegNum(v)
x := gc.SSARegNum(v.Args[0])
if r != x {
p := gc.Prog(moveByType(v.Type))
p.From.Type = obj.TYPE_REG
p.From.Reg = x
p.To.Type = obj.TYPE_REG
p.To.Reg = r
}
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_CONST
p.From.Offset = v.AuxInt
p.To.Type = obj.TYPE_REG
p.To.Reg = r
// TODO: Teach doasm to compile the three-address multiply imul $c, r1, r2
// instead of using the MOVQ above.
//p.From3 = new(obj.Addr)
//p.From3.Type = obj.TYPE_REG
//p.From3.Reg = gc.SSARegNum(v.Args[0])
case ssa.OpAMD64SUBQconst, ssa.OpAMD64SUBLconst, ssa.OpAMD64SUBWconst, ssa.OpAMD64SUBBconst:
x := gc.SSARegNum(v.Args[0])
r := gc.SSARegNum(v)
// We have 3-op add (lea), so transforming a = b - const into
// a = b + (- const), saves us 1 instruction. We can't fit
// - (-1 << 31) into 4 bytes offset in lea.
// We handle 2-address just fine below.
if v.AuxInt == -1<<31 || x == r {
if x != r {
// This code compensates for the fact that the register allocator
// doesn't understand 2-address instructions yet. TODO: fix that.
p := gc.Prog(moveByType(v.Type))
p.From.Type = obj.TYPE_REG
p.From.Reg = x
p.To.Type = obj.TYPE_REG
p.To.Reg = r
}
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_CONST
p.From.Offset = v.AuxInt
p.To.Type = obj.TYPE_REG
p.To.Reg = r
} else if x == r && v.AuxInt == -1 {
var asm obj.As
// x = x - (-1) is the same as x++
// See OpAMD64ADDQconst comments about inc vs add $1,reg
if v.Op == ssa.OpAMD64SUBQconst {
asm = x86.AINCQ
} else {
asm = x86.AINCL
}
p := gc.Prog(asm)
p.To.Type = obj.TYPE_REG
p.To.Reg = r
} else if x == r && v.AuxInt == 1 {
var asm obj.As
if v.Op == ssa.OpAMD64SUBQconst {
asm = x86.ADECQ
} else {
asm = x86.ADECL
}
p := gc.Prog(asm)
p.To.Type = obj.TYPE_REG
p.To.Reg = r
} else {
var asm obj.As
if v.Op == ssa.OpAMD64SUBQconst {
asm = x86.ALEAQ
} else {
asm = x86.ALEAL
}
p := gc.Prog(asm)
p.From.Type = obj.TYPE_MEM
p.From.Reg = x
p.From.Offset = -v.AuxInt
p.To.Type = obj.TYPE_REG
p.To.Reg = r
}
case ssa.OpAMD64ANDQconst, ssa.OpAMD64ANDLconst, ssa.OpAMD64ANDWconst, ssa.OpAMD64ANDBconst,
ssa.OpAMD64ORQconst, ssa.OpAMD64ORLconst, ssa.OpAMD64ORWconst, ssa.OpAMD64ORBconst,
ssa.OpAMD64XORQconst, ssa.OpAMD64XORLconst, ssa.OpAMD64XORWconst, ssa.OpAMD64XORBconst,
ssa.OpAMD64SHLQconst, ssa.OpAMD64SHLLconst, ssa.OpAMD64SHLWconst,
ssa.OpAMD64SHLBconst, ssa.OpAMD64SHRQconst, ssa.OpAMD64SHRLconst, ssa.OpAMD64SHRWconst,
ssa.OpAMD64SHRBconst, ssa.OpAMD64SARQconst, ssa.OpAMD64SARLconst, ssa.OpAMD64SARWconst,
ssa.OpAMD64SARBconst, ssa.OpAMD64ROLQconst, ssa.OpAMD64ROLLconst, ssa.OpAMD64ROLWconst,
ssa.OpAMD64ROLBconst:
// This code compensates for the fact that the register allocator
// doesn't understand 2-address instructions yet. TODO: fix that.
x := gc.SSARegNum(v.Args[0])
r := gc.SSARegNum(v)
if x != r {
p := gc.Prog(moveByType(v.Type))
p.From.Type = obj.TYPE_REG
p.From.Reg = x
p.To.Type = obj.TYPE_REG
p.To.Reg = r
}
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_CONST
p.From.Offset = v.AuxInt
p.To.Type = obj.TYPE_REG
p.To.Reg = r
case ssa.OpAMD64SBBQcarrymask, ssa.OpAMD64SBBLcarrymask:
r := gc.SSARegNum(v)
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_REG
p.From.Reg = r
p.To.Type = obj.TYPE_REG
p.To.Reg = r
case ssa.OpAMD64LEAQ1, ssa.OpAMD64LEAQ2, ssa.OpAMD64LEAQ4, ssa.OpAMD64LEAQ8:
r := gc.SSARegNum(v.Args[0])
i := gc.SSARegNum(v.Args[1])
p := gc.Prog(x86.ALEAQ)
switch v.Op {
case ssa.OpAMD64LEAQ1:
p.From.Scale = 1
if i == x86.REG_SP {
r, i = i, r
}
case ssa.OpAMD64LEAQ2:
p.From.Scale = 2
case ssa.OpAMD64LEAQ4:
p.From.Scale = 4
case ssa.OpAMD64LEAQ8:
p.From.Scale = 8
}
p.From.Type = obj.TYPE_MEM
p.From.Reg = r
p.From.Index = i
gc.AddAux(&p.From, v)
p.To.Type = obj.TYPE_REG
p.To.Reg = gc.SSARegNum(v)
case ssa.OpAMD64LEAQ:
p := gc.Prog(x86.ALEAQ)
p.From.Type = obj.TYPE_MEM
p.From.Reg = gc.SSARegNum(v.Args[0])
gc.AddAux(&p.From, v)
p.To.Type = obj.TYPE_REG
p.To.Reg = gc.SSARegNum(v)
case ssa.OpAMD64CMPQ, ssa.OpAMD64CMPL, ssa.OpAMD64CMPW, ssa.OpAMD64CMPB,
ssa.OpAMD64TESTQ, ssa.OpAMD64TESTL, ssa.OpAMD64TESTW, ssa.OpAMD64TESTB:
opregreg(v.Op.Asm(), gc.SSARegNum(v.Args[1]), gc.SSARegNum(v.Args[0]))
case ssa.OpAMD64UCOMISS, ssa.OpAMD64UCOMISD:
// Go assembler has swapped operands for UCOMISx relative to CMP,
// must account for that right here.
opregreg(v.Op.Asm(), gc.SSARegNum(v.Args[0]), gc.SSARegNum(v.Args[1]))
case ssa.OpAMD64CMPQconst, ssa.OpAMD64CMPLconst, ssa.OpAMD64CMPWconst, ssa.OpAMD64CMPBconst:
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_REG
p.From.Reg = gc.SSARegNum(v.Args[0])
p.To.Type = obj.TYPE_CONST
p.To.Offset = v.AuxInt
case ssa.OpAMD64TESTQconst, ssa.OpAMD64TESTLconst, ssa.OpAMD64TESTWconst, ssa.OpAMD64TESTBconst:
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_CONST
p.From.Offset = v.AuxInt
p.To.Type = obj.TYPE_REG
p.To.Reg = gc.SSARegNum(v.Args[0])
case ssa.OpAMD64MOVBconst, ssa.OpAMD64MOVWconst, ssa.OpAMD64MOVLconst, ssa.OpAMD64MOVQconst:
x := gc.SSARegNum(v)
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_CONST
p.From.Offset = v.AuxInt
p.To.Type = obj.TYPE_REG
p.To.Reg = x
// If flags are live at this instruction, suppress the
// MOV $0,AX -> XOR AX,AX optimization.
if v.Aux != nil {
p.Mark |= x86.PRESERVEFLAGS
}
case ssa.OpAMD64MOVSSconst, ssa.OpAMD64MOVSDconst:
x := gc.SSARegNum(v)
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_FCONST
p.From.Val = math.Float64frombits(uint64(v.AuxInt))
p.To.Type = obj.TYPE_REG
p.To.Reg = x
case ssa.OpAMD64MOVQload, ssa.OpAMD64MOVSSload, ssa.OpAMD64MOVSDload, ssa.OpAMD64MOVLload, ssa.OpAMD64MOVWload, ssa.OpAMD64MOVBload, ssa.OpAMD64MOVBQSXload, ssa.OpAMD64MOVWQSXload, ssa.OpAMD64MOVLQSXload, ssa.OpAMD64MOVOload:
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_MEM
p.From.Reg = gc.SSARegNum(v.Args[0])
gc.AddAux(&p.From, v)
p.To.Type = obj.TYPE_REG
p.To.Reg = gc.SSARegNum(v)
case ssa.OpAMD64MOVQloadidx8, ssa.OpAMD64MOVSDloadidx8:
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_MEM
p.From.Reg = gc.SSARegNum(v.Args[0])
gc.AddAux(&p.From, v)
p.From.Scale = 8
p.From.Index = gc.SSARegNum(v.Args[1])
p.To.Type = obj.TYPE_REG
p.To.Reg = gc.SSARegNum(v)
case ssa.OpAMD64MOVLloadidx4, ssa.OpAMD64MOVSSloadidx4:
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_MEM
p.From.Reg = gc.SSARegNum(v.Args[0])
gc.AddAux(&p.From, v)
p.From.Scale = 4
p.From.Index = gc.SSARegNum(v.Args[1])
p.To.Type = obj.TYPE_REG
p.To.Reg = gc.SSARegNum(v)
case ssa.OpAMD64MOVWloadidx2:
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_MEM
p.From.Reg = gc.SSARegNum(v.Args[0])
gc.AddAux(&p.From, v)
p.From.Scale = 2
p.From.Index = gc.SSARegNum(v.Args[1])
p.To.Type = obj.TYPE_REG
p.To.Reg = gc.SSARegNum(v)
case ssa.OpAMD64MOVBloadidx1, ssa.OpAMD64MOVWloadidx1, ssa.OpAMD64MOVLloadidx1, ssa.OpAMD64MOVQloadidx1, ssa.OpAMD64MOVSSloadidx1, ssa.OpAMD64MOVSDloadidx1:
r := gc.SSARegNum(v.Args[0])
i := gc.SSARegNum(v.Args[1])
if i == x86.REG_SP {
r, i = i, r
}
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_MEM
p.From.Reg = r
p.From.Scale = 1
p.From.Index = i
gc.AddAux(&p.From, v)
p.To.Type = obj.TYPE_REG
p.To.Reg = gc.SSARegNum(v)
case ssa.OpAMD64MOVQstore, ssa.OpAMD64MOVSSstore, ssa.OpAMD64MOVSDstore, ssa.OpAMD64MOVLstore, ssa.OpAMD64MOVWstore, ssa.OpAMD64MOVBstore, ssa.OpAMD64MOVOstore:
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_REG
p.From.Reg = gc.SSARegNum(v.Args[1])
p.To.Type = obj.TYPE_MEM
p.To.Reg = gc.SSARegNum(v.Args[0])
gc.AddAux(&p.To, v)
case ssa.OpAMD64MOVQstoreidx8, ssa.OpAMD64MOVSDstoreidx8:
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_REG
p.From.Reg = gc.SSARegNum(v.Args[2])
p.To.Type = obj.TYPE_MEM
p.To.Reg = gc.SSARegNum(v.Args[0])
p.To.Scale = 8
p.To.Index = gc.SSARegNum(v.Args[1])
gc.AddAux(&p.To, v)
case ssa.OpAMD64MOVSSstoreidx4, ssa.OpAMD64MOVLstoreidx4:
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_REG
p.From.Reg = gc.SSARegNum(v.Args[2])
p.To.Type = obj.TYPE_MEM
p.To.Reg = gc.SSARegNum(v.Args[0])
p.To.Scale = 4
p.To.Index = gc.SSARegNum(v.Args[1])
gc.AddAux(&p.To, v)
case ssa.OpAMD64MOVWstoreidx2:
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_REG
p.From.Reg = gc.SSARegNum(v.Args[2])
p.To.Type = obj.TYPE_MEM
p.To.Reg = gc.SSARegNum(v.Args[0])
p.To.Scale = 2
p.To.Index = gc.SSARegNum(v.Args[1])
gc.AddAux(&p.To, v)
case ssa.OpAMD64MOVBstoreidx1, ssa.OpAMD64MOVWstoreidx1, ssa.OpAMD64MOVLstoreidx1, ssa.OpAMD64MOVQstoreidx1, ssa.OpAMD64MOVSSstoreidx1, ssa.OpAMD64MOVSDstoreidx1:
r := gc.SSARegNum(v.Args[0])
i := gc.SSARegNum(v.Args[1])
if i == x86.REG_SP {
r, i = i, r
}
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_REG
p.From.Reg = gc.SSARegNum(v.Args[2])
p.To.Type = obj.TYPE_MEM
p.To.Reg = r
p.To.Scale = 1
p.To.Index = i
gc.AddAux(&p.To, v)
case ssa.OpAMD64MOVQstoreconst, ssa.OpAMD64MOVLstoreconst, ssa.OpAMD64MOVWstoreconst, ssa.OpAMD64MOVBstoreconst:
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_CONST
sc := v.AuxValAndOff()
p.From.Offset = sc.Val()
p.To.Type = obj.TYPE_MEM
p.To.Reg = gc.SSARegNum(v.Args[0])
gc.AddAux2(&p.To, v, sc.Off())
case ssa.OpAMD64MOVQstoreconstidx1, ssa.OpAMD64MOVQstoreconstidx8, ssa.OpAMD64MOVLstoreconstidx1, ssa.OpAMD64MOVLstoreconstidx4, ssa.OpAMD64MOVWstoreconstidx1, ssa.OpAMD64MOVWstoreconstidx2, ssa.OpAMD64MOVBstoreconstidx1:
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_CONST
sc := v.AuxValAndOff()
p.From.Offset = sc.Val()
r := gc.SSARegNum(v.Args[0])
i := gc.SSARegNum(v.Args[1])
switch v.Op {
case ssa.OpAMD64MOVBstoreconstidx1, ssa.OpAMD64MOVWstoreconstidx1, ssa.OpAMD64MOVLstoreconstidx1, ssa.OpAMD64MOVQstoreconstidx1:
p.To.Scale = 1
if i == x86.REG_SP {
r, i = i, r
}
case ssa.OpAMD64MOVWstoreconstidx2:
p.To.Scale = 2
case ssa.OpAMD64MOVLstoreconstidx4:
p.To.Scale = 4
case ssa.OpAMD64MOVQstoreconstidx8:
p.To.Scale = 8
}
p.To.Type = obj.TYPE_MEM
p.To.Reg = r
p.To.Index = i
gc.AddAux2(&p.To, v, sc.Off())
case ssa.OpAMD64MOVLQSX, ssa.OpAMD64MOVWQSX, ssa.OpAMD64MOVBQSX, ssa.OpAMD64MOVLQZX, ssa.OpAMD64MOVWQZX, ssa.OpAMD64MOVBQZX,
ssa.OpAMD64CVTSL2SS, ssa.OpAMD64CVTSL2SD, ssa.OpAMD64CVTSQ2SS, ssa.OpAMD64CVTSQ2SD,
ssa.OpAMD64CVTTSS2SL, ssa.OpAMD64CVTTSD2SL, ssa.OpAMD64CVTTSS2SQ, ssa.OpAMD64CVTTSD2SQ,
ssa.OpAMD64CVTSS2SD, ssa.OpAMD64CVTSD2SS:
opregreg(v.Op.Asm(), gc.SSARegNum(v), gc.SSARegNum(v.Args[0]))
case ssa.OpAMD64DUFFZERO:
p := gc.Prog(obj.ADUFFZERO)
p.To.Type = obj.TYPE_ADDR
p.To.Sym = gc.Linksym(gc.Pkglookup("duffzero", gc.Runtimepkg))
p.To.Offset = v.AuxInt
case ssa.OpAMD64MOVOconst:
if v.AuxInt != 0 {
v.Unimplementedf("MOVOconst can only do constant=0")
}
r := gc.SSARegNum(v)
opregreg(x86.AXORPS, r, r)
case ssa.OpAMD64DUFFCOPY:
p := gc.Prog(obj.ADUFFCOPY)
p.To.Type = obj.TYPE_ADDR
p.To.Sym = gc.Linksym(gc.Pkglookup("duffcopy", gc.Runtimepkg))
p.To.Offset = v.AuxInt
case ssa.OpCopy, ssa.OpAMD64MOVQconvert: // TODO: use MOVQreg for reg->reg copies instead of OpCopy?
if v.Type.IsMemory() {
return
}
x := gc.SSARegNum(v.Args[0])
y := gc.SSARegNum(v)
if x != y {
opregreg(moveByType(v.Type), y, x)
}
case ssa.OpLoadReg:
if v.Type.IsFlags() {
v.Unimplementedf("load flags not implemented: %v", v.LongString())
return
}
p := gc.Prog(loadByType(v.Type))
n, off := gc.AutoVar(v.Args[0])
p.From.Type = obj.TYPE_MEM
p.From.Node = n
p.From.Sym = gc.Linksym(n.Sym)
p.From.Offset = off
if n.Class == gc.PPARAM || n.Class == gc.PPARAMOUT {
p.From.Name = obj.NAME_PARAM
p.From.Offset += n.Xoffset
} else {
p.From.Name = obj.NAME_AUTO
}
p.To.Type = obj.TYPE_REG
p.To.Reg = gc.SSARegNum(v)
case ssa.OpStoreReg:
if v.Type.IsFlags() {
v.Unimplementedf("store flags not implemented: %v", v.LongString())
return
}
p := gc.Prog(storeByType(v.Type))
p.From.Type = obj.TYPE_REG
p.From.Reg = gc.SSARegNum(v.Args[0])
n, off := gc.AutoVar(v)
p.To.Type = obj.TYPE_MEM
p.To.Node = n
p.To.Sym = gc.Linksym(n.Sym)
p.To.Offset = off
if n.Class == gc.PPARAM || n.Class == gc.PPARAMOUT {
p.To.Name = obj.NAME_PARAM
p.To.Offset += n.Xoffset
} else {
p.To.Name = obj.NAME_AUTO
}
case ssa.OpPhi:
// just check to make sure regalloc and stackalloc did it right
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)
}
}
case ssa.OpInitMem:
// memory arg needs no code
case ssa.OpArg:
// input args need no code
case ssa.OpAMD64LoweredGetClosurePtr:
// Output is hardwired to DX only,
// and DX contains the closure pointer on
// closure entry, and this "instruction"
// is scheduled to the very beginning
// of the entry block.
case ssa.OpAMD64LoweredGetG:
r := gc.SSARegNum(v)
// See the comments in cmd/internal/obj/x86/obj6.go
// near CanUse1InsnTLS for a detailed explanation of these instructions.
if x86.CanUse1InsnTLS(gc.Ctxt) {
// MOVQ (TLS), r
p := gc.Prog(x86.AMOVQ)
p.From.Type = obj.TYPE_MEM
p.From.Reg = x86.REG_TLS
p.To.Type = obj.TYPE_REG
p.To.Reg = r
} else {
// MOVQ TLS, r
// MOVQ (r)(TLS*1), r
p := gc.Prog(x86.AMOVQ)
p.From.Type = obj.TYPE_REG
p.From.Reg = x86.REG_TLS
p.To.Type = obj.TYPE_REG
p.To.Reg = r
q := gc.Prog(x86.AMOVQ)
q.From.Type = obj.TYPE_MEM
q.From.Reg = r
q.From.Index = x86.REG_TLS
q.From.Scale = 1
q.To.Type = obj.TYPE_REG
q.To.Reg = r
}
case ssa.OpAMD64CALLstatic:
if v.Aux.(*gc.Sym) == gc.Deferreturn.Sym {
// Deferred calls will appear to be returning to
// the CALL deferreturn(SB) that we are about to emit.
// However, the stack trace code will show the line
// of the instruction byte before the return PC.
// To avoid that being an unrelated instruction,
// insert an actual hardware NOP that will have the right line number.
// This is different from obj.ANOP, which is a virtual no-op
// that doesn't make it into the instruction stream.
ginsnop()
}
p := gc.Prog(obj.ACALL)
p.To.Type = obj.TYPE_MEM
p.To.Name = obj.NAME_EXTERN
p.To.Sym = gc.Linksym(v.Aux.(*gc.Sym))
if gc.Maxarg < v.AuxInt {
gc.Maxarg = v.AuxInt
}
case ssa.OpAMD64CALLclosure:
p := gc.Prog(obj.ACALL)
p.To.Type = obj.TYPE_REG
p.To.Reg = gc.SSARegNum(v.Args[0])
if gc.Maxarg < v.AuxInt {
gc.Maxarg = v.AuxInt
}
case ssa.OpAMD64CALLdefer:
p := gc.Prog(obj.ACALL)
p.To.Type = obj.TYPE_MEM
p.To.Name = obj.NAME_EXTERN
p.To.Sym = gc.Linksym(gc.Deferproc.Sym)
if gc.Maxarg < v.AuxInt {
gc.Maxarg = v.AuxInt
}
case ssa.OpAMD64CALLgo:
p := gc.Prog(obj.ACALL)
p.To.Type = obj.TYPE_MEM
p.To.Name = obj.NAME_EXTERN
p.To.Sym = gc.Linksym(gc.Newproc.Sym)
if gc.Maxarg < v.AuxInt {
gc.Maxarg = v.AuxInt
}
case ssa.OpAMD64CALLinter:
p := gc.Prog(obj.ACALL)
p.To.Type = obj.TYPE_REG
p.To.Reg = gc.SSARegNum(v.Args[0])
if gc.Maxarg < v.AuxInt {
gc.Maxarg = v.AuxInt
}
case ssa.OpAMD64NEGQ, ssa.OpAMD64NEGL, ssa.OpAMD64NEGW, ssa.OpAMD64NEGB,
ssa.OpAMD64BSWAPQ, ssa.OpAMD64BSWAPL,
ssa.OpAMD64NOTQ, ssa.OpAMD64NOTL, ssa.OpAMD64NOTW, ssa.OpAMD64NOTB:
x := gc.SSARegNum(v.Args[0])
r := gc.SSARegNum(v)
if x != r {
p := gc.Prog(moveByType(v.Type))
p.From.Type = obj.TYPE_REG
p.From.Reg = x
p.To.Type = obj.TYPE_REG
p.To.Reg = r
}
p := gc.Prog(v.Op.Asm())
p.To.Type = obj.TYPE_REG
p.To.Reg = r
case ssa.OpAMD64BSFQ, ssa.OpAMD64BSFL, ssa.OpAMD64BSFW,
ssa.OpAMD64BSRQ, ssa.OpAMD64BSRL, ssa.OpAMD64BSRW,
ssa.OpAMD64SQRTSD:
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_REG
p.From.Reg = gc.SSARegNum(v.Args[0])
p.To.Type = obj.TYPE_REG
p.To.Reg = gc.SSARegNum(v)
case ssa.OpSP, ssa.OpSB:
// nothing to do
case ssa.OpAMD64SETEQ, ssa.OpAMD64SETNE,
ssa.OpAMD64SETL, ssa.OpAMD64SETLE,
ssa.OpAMD64SETG, ssa.OpAMD64SETGE,
ssa.OpAMD64SETGF, ssa.OpAMD64SETGEF,
ssa.OpAMD64SETB, ssa.OpAMD64SETBE,
ssa.OpAMD64SETORD, ssa.OpAMD64SETNAN,
ssa.OpAMD64SETA, ssa.OpAMD64SETAE:
p := gc.Prog(v.Op.Asm())
p.To.Type = obj.TYPE_REG
p.To.Reg = gc.SSARegNum(v)
case ssa.OpAMD64SETNEF:
p := gc.Prog(v.Op.Asm())
p.To.Type = obj.TYPE_REG
p.To.Reg = gc.SSARegNum(v)
q := gc.Prog(x86.ASETPS)
q.To.Type = obj.TYPE_REG
q.To.Reg = x86.REG_AX
// ORL avoids partial register write and is smaller than ORQ, used by old compiler
opregreg(x86.AORL, gc.SSARegNum(v), x86.REG_AX)
case ssa.OpAMD64SETEQF:
p := gc.Prog(v.Op.Asm())
p.To.Type = obj.TYPE_REG
p.To.Reg = gc.SSARegNum(v)
q := gc.Prog(x86.ASETPC)
q.To.Type = obj.TYPE_REG
q.To.Reg = x86.REG_AX
// ANDL avoids partial register write and is smaller than ANDQ, used by old compiler
opregreg(x86.AANDL, gc.SSARegNum(v), x86.REG_AX)
case ssa.OpAMD64InvertFlags:
v.Fatalf("InvertFlags should never make it to codegen %v", v.LongString())
case ssa.OpAMD64FlagEQ, ssa.OpAMD64FlagLT_ULT, ssa.OpAMD64FlagLT_UGT, ssa.OpAMD64FlagGT_ULT, ssa.OpAMD64FlagGT_UGT:
v.Fatalf("Flag* ops should never make it to codegen %v", v.LongString())
case ssa.OpAMD64REPSTOSQ:
gc.Prog(x86.AREP)
gc.Prog(x86.ASTOSQ)
case ssa.OpAMD64REPMOVSQ:
gc.Prog(x86.AREP)
gc.Prog(x86.AMOVSQ)
case ssa.OpVarDef:
gc.Gvardef(v.Aux.(*gc.Node))
case ssa.OpVarKill:
gc.Gvarkill(v.Aux.(*gc.Node))
case ssa.OpVarLive:
gc.Gvarlive(v.Aux.(*gc.Node))
case ssa.OpAMD64LoweredNilCheck:
// Optimization - if the subsequent block has a load or store
// at the same address, we don't need to issue this instruction.
mem := v.Args[1]
for _, w := range v.Block.Succs[0].Values {
if w.Op == ssa.OpPhi {
if w.Type.IsMemory() {
mem = w
}
continue
}
if len(w.Args) == 0 || !w.Args[len(w.Args)-1].Type.IsMemory() {
// w doesn't use a store - can't be a memory op.
continue
}
if w.Args[len(w.Args)-1] != mem {
v.Fatalf("wrong store after nilcheck v=%s w=%s", v, w)
}
switch w.Op {
case ssa.OpAMD64MOVQload, ssa.OpAMD64MOVLload, ssa.OpAMD64MOVWload, ssa.OpAMD64MOVBload,
ssa.OpAMD64MOVQstore, ssa.OpAMD64MOVLstore, ssa.OpAMD64MOVWstore, ssa.OpAMD64MOVBstore,
ssa.OpAMD64MOVBQSXload, ssa.OpAMD64MOVWQSXload, ssa.OpAMD64MOVLQSXload,
ssa.OpAMD64MOVSSload, ssa.OpAMD64MOVSDload, ssa.OpAMD64MOVOload,
ssa.OpAMD64MOVSSstore, ssa.OpAMD64MOVSDstore, ssa.OpAMD64MOVOstore:
if w.Args[0] == v.Args[0] && w.Aux == nil && w.AuxInt >= 0 && w.AuxInt < minZeroPage {
if gc.Debug_checknil != 0 && int(v.Line) > 1 {
gc.Warnl(v.Line, "removed nil check")
}
return
}
case ssa.OpAMD64MOVQstoreconst, ssa.OpAMD64MOVLstoreconst, ssa.OpAMD64MOVWstoreconst, ssa.OpAMD64MOVBstoreconst:
off := ssa.ValAndOff(v.AuxInt).Off()
if w.Args[0] == v.Args[0] && w.Aux == nil && off >= 0 && off < minZeroPage {
if gc.Debug_checknil != 0 && int(v.Line) > 1 {
gc.Warnl(v.Line, "removed nil check")
}
return
}
}
if w.Type.IsMemory() {
if w.Op == ssa.OpVarDef || w.Op == ssa.OpVarKill || w.Op == ssa.OpVarLive {
// these ops are OK
mem = w
continue
}
// We can't delay the nil check past the next store.
break
}
}
// Issue a load which will fault if the input is nil.
// TODO: We currently use the 2-byte instruction TESTB AX, (reg).
// Should we use the 3-byte TESTB $0, (reg) instead? It is larger
// but it doesn't have false dependency on AX.
// Or maybe allocate an output register and use MOVL (reg),reg2 ?
// That trades clobbering flags for clobbering a register.
p := gc.Prog(x86.ATESTB)
p.From.Type = obj.TYPE_REG
p.From.Reg = x86.REG_AX
p.To.Type = obj.TYPE_MEM
p.To.Reg = gc.SSARegNum(v.Args[0])
gc.AddAux(&p.To, v)
if gc.Debug_checknil != 0 && v.Line > 1 { // v.Line==1 in generated wrappers
gc.Warnl(v.Line, "generated nil check")
}
default:
v.Unimplementedf("genValue not implemented: %s", v.LongString())
}
}
var blockJump = [...]struct {
asm, invasm obj.As
}{
ssa.BlockAMD64EQ: {x86.AJEQ, x86.AJNE},
ssa.BlockAMD64NE: {x86.AJNE, x86.AJEQ},
ssa.BlockAMD64LT: {x86.AJLT, x86.AJGE},
ssa.BlockAMD64GE: {x86.AJGE, x86.AJLT},
ssa.BlockAMD64LE: {x86.AJLE, x86.AJGT},
ssa.BlockAMD64GT: {x86.AJGT, x86.AJLE},
ssa.BlockAMD64ULT: {x86.AJCS, x86.AJCC},
ssa.BlockAMD64UGE: {x86.AJCC, x86.AJCS},
ssa.BlockAMD64UGT: {x86.AJHI, x86.AJLS},
ssa.BlockAMD64ULE: {x86.AJLS, x86.AJHI},
ssa.BlockAMD64ORD: {x86.AJPC, x86.AJPS},
ssa.BlockAMD64NAN: {x86.AJPS, x86.AJPC},
}
var eqfJumps = [2][2]gc.FloatingEQNEJump{
{{x86.AJNE, 1}, {x86.AJPS, 1}}, // next == b.Succs[0]
{{x86.AJNE, 1}, {x86.AJPC, 0}}, // next == b.Succs[1]
}
var nefJumps = [2][2]gc.FloatingEQNEJump{
{{x86.AJNE, 0}, {x86.AJPC, 1}}, // next == b.Succs[0]
{{x86.AJNE, 0}, {x86.AJPS, 0}}, // next == b.Succs[1]
}
func ssaGenBlock(s *gc.SSAGenState, b, next *ssa.Block) {
s.SetLineno(b.Line)
switch b.Kind {
case ssa.BlockPlain, ssa.BlockCall, ssa.BlockCheck:
if b.Succs[0] != next {
p := gc.Prog(obj.AJMP)
p.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{p, b.Succs[0]})
}
case ssa.BlockDefer:
// defer returns in rax:
// 0 if we should continue executing
// 1 if we should jump to deferreturn call
p := gc.Prog(x86.ATESTL)
p.From.Type = obj.TYPE_REG
p.From.Reg = x86.REG_AX
p.To.Type = obj.TYPE_REG
p.To.Reg = x86.REG_AX
p = gc.Prog(x86.AJNE)
p.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{p, b.Succs[1]})
if b.Succs[0] != next {
p := gc.Prog(obj.AJMP)
p.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{p, b.Succs[0]})
}
case ssa.BlockExit:
gc.Prog(obj.AUNDEF) // tell plive.go that we never reach here
case ssa.BlockRet:
gc.Prog(obj.ARET)
case ssa.BlockRetJmp:
p := gc.Prog(obj.AJMP)
p.To.Type = obj.TYPE_MEM
p.To.Name = obj.NAME_EXTERN
p.To.Sym = gc.Linksym(b.Aux.(*gc.Sym))
case ssa.BlockAMD64EQF:
gc.SSAGenFPJump(s, b, next, &eqfJumps)
case ssa.BlockAMD64NEF:
gc.SSAGenFPJump(s, b, next, &nefJumps)
case ssa.BlockAMD64EQ, ssa.BlockAMD64NE,
ssa.BlockAMD64LT, ssa.BlockAMD64GE,
ssa.BlockAMD64LE, ssa.BlockAMD64GT,
ssa.BlockAMD64ULT, ssa.BlockAMD64UGT,
ssa.BlockAMD64ULE, ssa.BlockAMD64UGE:
jmp := blockJump[b.Kind]
likely := b.Likely
var p *obj.Prog
switch next {
case b.Succs[0]:
p = gc.Prog(jmp.invasm)
likely *= -1
p.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{p, b.Succs[1]})
case b.Succs[1]:
p = gc.Prog(jmp.asm)
p.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{p, b.Succs[0]})
default:
p = gc.Prog(jmp.asm)
p.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{p, b.Succs[0]})
q := gc.Prog(obj.AJMP)
q.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{q, b.Succs[1]})
}
// 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
}
default:
b.Unimplementedf("branch not implemented: %s. Control: %s", b.LongString(), b.Control.LongString())
}
}
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