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| author | Keith Randall <khr@golang.org> | 2015-08-11 12:51:33 -0700 |
|---|---|---|
| committer | Keith Randall <khr@golang.org> | 2015-08-17 21:06:30 +0000 |
| commit | 0b46b42943ee9d7ad4e9a19772d22468718173c9 (patch) | |
| tree | 6e1a374e1ef13e8b88bf800833944afa8f3e7a15 /src/cmd/compile/internal/ssa/deadcode.go | |
| parent | 759b9c3b80da47a8db59f015bfca551a2a15ae18 (diff) | |
| download | go-0b46b42943ee9d7ad4e9a19772d22468718173c9.tar.gz go-0b46b42943ee9d7ad4e9a19772d22468718173c9.zip | |
[dev.ssa] cmd/compile/internal/ssa: New register allocator
Implement a global (whole function) register allocator.
This replaces the local (per basic block) register allocator.
Clobbering of registers by instructions is handled properly.
A separate change will add the correct clobbers to all the instructions.
Change-Id: I38ce4dc7dccb8303c1c0e0295fe70247b0a3f2ea
Reviewed-on: https://go-review.googlesource.com/13622
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Todd Neal <todd@tneal.org>
Diffstat (limited to 'src/cmd/compile/internal/ssa/deadcode.go')
| -rw-r--r-- | src/cmd/compile/internal/ssa/deadcode.go | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/ssa/deadcode.go b/src/cmd/compile/internal/ssa/deadcode.go index 109b3dd09f..8c306c8412 100644 --- a/src/cmd/compile/internal/ssa/deadcode.go +++ b/src/cmd/compile/internal/ssa/deadcode.go @@ -59,6 +59,14 @@ func findlive(f *Func) (reachable []bool, live []bool) { // deadcode removes dead code from f. func deadcode(f *Func) { + // deadcode after regalloc is forbidden for now. Regalloc + // doesn't quite generate legal SSA which will lead to some + // required moves being eliminated. See the comment at the + // top of regalloc.go for details. + if f.RegAlloc != nil { + f.Fatalf("deadcode after regalloc") + } + reachable, live := findlive(f) // Remove dead values from blocks' value list. Return dead |