mirror of
https://github.com/golang/go.git
synced 2025-05-29 03:11:26 +00:00
61aa0953e5
Add label and goto checks and improve test coverage. Implement OSWITCH and OSELECT. Implement OBREAK and OCONTINUE. Allow generation of code in dead blocks. Change-Id: Ibebb7c98b4b2344f46d38db7c9dce058c56beaac Reviewed-on: https://go-review.googlesource.com/12445 Reviewed-by: Keith Randall <khr@golang.org>
123 lines
3.2 KiB
Go
123 lines
3.2 KiB
Go
// 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 ssa
|
|
|
|
import "log"
|
|
|
|
// Compile is the main entry point for this package.
|
|
// Compile modifies f so that on return:
|
|
// · all Values in f map to 0 or 1 assembly instructions of the target architecture
|
|
// · the order of f.Blocks is the order to emit the Blocks
|
|
// · the order of b.Values is the order to emit the Values in each Block
|
|
// · f has a non-nil regAlloc field
|
|
func Compile(f *Func) {
|
|
// TODO: debugging - set flags to control verbosity of compiler,
|
|
// which phases to dump IR before/after, etc.
|
|
f.Logf("compiling %s\n", f.Name)
|
|
|
|
// hook to print function & phase if panic happens
|
|
phaseName := "init"
|
|
defer func() {
|
|
if phaseName != "" {
|
|
f.Fatalf("panic during %s while compiling %s\n", phaseName, f.Name)
|
|
}
|
|
}()
|
|
|
|
// Run all the passes
|
|
printFunc(f)
|
|
checkFunc(f)
|
|
for _, p := range passes {
|
|
phaseName = p.name
|
|
f.Logf(" pass %s begin\n", p.name)
|
|
p.fn(f)
|
|
f.Logf(" pass %s end\n", p.name)
|
|
printFunc(f)
|
|
checkFunc(f)
|
|
}
|
|
|
|
// Squash error printing defer
|
|
phaseName = ""
|
|
}
|
|
|
|
type pass struct {
|
|
name string
|
|
fn func(*Func)
|
|
}
|
|
|
|
// list of passes for the compiler
|
|
var passes = [...]pass{
|
|
{"phielim", phielim},
|
|
{"copyelim", copyelim},
|
|
{"early deadcode", deadcode}, // remove generated dead code to avoid doing pointless work during opt
|
|
{"opt", opt},
|
|
{"opt deadcode", deadcode}, // remove any blocks orphaned during opt
|
|
{"generic cse", cse},
|
|
{"nilcheckelim", nilcheckelim},
|
|
{"generic deadcode", deadcode},
|
|
{"dse", dse},
|
|
{"fuse", fuse},
|
|
{"lower", lower},
|
|
{"lowered cse", cse},
|
|
{"lowered deadcode", deadcode},
|
|
{"critical", critical}, // remove critical edges
|
|
{"layout", layout}, // schedule blocks
|
|
{"schedule", schedule}, // schedule values
|
|
{"regalloc", regalloc},
|
|
{"stackalloc", stackalloc},
|
|
}
|
|
|
|
// Double-check phase ordering constraints.
|
|
// This code is intended to document the ordering requirements
|
|
// between different phases. It does not override the passes
|
|
// list above.
|
|
type constraint struct {
|
|
a, b string // a must come before b
|
|
}
|
|
|
|
var passOrder = [...]constraint{
|
|
// common-subexpression before dead-store elim, so that we recognize
|
|
// when two address expressions are the same.
|
|
{"generic cse", "dse"},
|
|
// cse substantially improves nilcheckelim efficacy
|
|
{"generic cse", "nilcheckelim"},
|
|
// allow deadcode to clean up after nilcheckelim
|
|
{"nilcheckelim", "generic deadcode"},
|
|
// nilcheckelim generates sequences of plain basic blocks
|
|
{"nilcheckelim", "fuse"},
|
|
// don't layout blocks until critical edges have been removed
|
|
{"critical", "layout"},
|
|
// regalloc requires the removal of all critical edges
|
|
{"critical", "regalloc"},
|
|
// regalloc requires all the values in a block to be scheduled
|
|
{"schedule", "regalloc"},
|
|
// stack allocation requires register allocation
|
|
{"regalloc", "stackalloc"},
|
|
}
|
|
|
|
func init() {
|
|
for _, c := range passOrder {
|
|
a, b := c.a, c.b
|
|
i := -1
|
|
j := -1
|
|
for k, p := range passes {
|
|
if p.name == a {
|
|
i = k
|
|
}
|
|
if p.name == b {
|
|
j = k
|
|
}
|
|
}
|
|
if i < 0 {
|
|
log.Panicf("pass %s not found", a)
|
|
}
|
|
if j < 0 {
|
|
log.Panicf("pass %s not found", b)
|
|
}
|
|
if i >= j {
|
|
log.Panicf("passes %s and %s out of order", a, b)
|
|
}
|
|
}
|
|
}
|