diff options
| author | Jorropo <jorropo.pgm@gmail.com> | 2025-11-18 01:42:37 +0100 |
|---|---|---|
| committer | Gopher Robot <gobot@golang.org> | 2025-11-21 12:37:30 -0800 |
| commit | ec92bc6d63efdbd1e04b7590b8ec3ea5236503e0 (patch) | |
| tree | df6444de3fa55fd85dab213762f592e81a2998d0 /src | |
| parent | 3820f94c1d081921494ada1da64b4fab21ae1a48 (diff) | |
| download | go-ec92bc6d63efdbd1e04b7590b8ec3ea5236503e0.tar.xz | |
cmd/compile: rewrite Rsh to RshU if arguments are proved positive
Fixes #76332
Change-Id: I9044025d5dc599531c7f88ed2870bcf3d8b0acbd
Reviewed-on: https://go-review.googlesource.com/c/go/+/721206
Reviewed-by: Mark Freeman <markfreeman@google.com>
Reviewed-by: Keith Randall <khr@google.com>
Auto-Submit: Jorropo <jorropo.pgm@gmail.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@golang.org>
Diffstat (limited to 'src')
| -rw-r--r-- | src/cmd/compile/internal/ssa/prove.go | 43 |
1 files changed, 33 insertions, 10 deletions
diff --git a/src/cmd/compile/internal/ssa/prove.go b/src/cmd/compile/internal/ssa/prove.go index f6175a3bd7..5581da445d 100644 --- a/src/cmd/compile/internal/ssa/prove.go +++ b/src/cmd/compile/internal/ssa/prove.go @@ -2664,14 +2664,30 @@ var mostNegativeDividend = map[Op]int64{ OpMod64: -1 << 63, } var unsignedOp = map[Op]Op{ - OpDiv8: OpDiv8u, - OpDiv16: OpDiv16u, - OpDiv32: OpDiv32u, - OpDiv64: OpDiv64u, - OpMod8: OpMod8u, - OpMod16: OpMod16u, - OpMod32: OpMod32u, - OpMod64: OpMod64u, + OpDiv8: OpDiv8u, + OpDiv16: OpDiv16u, + OpDiv32: OpDiv32u, + OpDiv64: OpDiv64u, + OpMod8: OpMod8u, + OpMod16: OpMod16u, + OpMod32: OpMod32u, + OpMod64: OpMod64u, + OpRsh8x8: OpRsh8Ux8, + OpRsh8x16: OpRsh8Ux16, + OpRsh8x32: OpRsh8Ux32, + OpRsh8x64: OpRsh8Ux64, + OpRsh16x8: OpRsh16Ux8, + OpRsh16x16: OpRsh16Ux16, + OpRsh16x32: OpRsh16Ux32, + OpRsh16x64: OpRsh16Ux64, + OpRsh32x8: OpRsh32Ux8, + OpRsh32x16: OpRsh32Ux16, + OpRsh32x32: OpRsh32Ux32, + OpRsh32x64: OpRsh32Ux64, + OpRsh64x8: OpRsh64Ux8, + OpRsh64x16: OpRsh64Ux16, + OpRsh64x32: OpRsh64Ux32, + OpRsh64x64: OpRsh64Ux64, } var bytesizeToConst = [...]Op{ @@ -2758,8 +2774,15 @@ func simplifyBlock(sdom SparseTree, ft *factsTable, b *Block) { case OpRsh8x8, OpRsh8x16, OpRsh8x32, OpRsh8x64, OpRsh16x8, OpRsh16x16, OpRsh16x32, OpRsh16x64, OpRsh32x8, OpRsh32x16, OpRsh32x32, OpRsh32x64, - OpRsh64x8, OpRsh64x16, OpRsh64x32, OpRsh64x64, - OpLsh8x8, OpLsh8x16, OpLsh8x32, OpLsh8x64, + OpRsh64x8, OpRsh64x16, OpRsh64x32, OpRsh64x64: + if ft.isNonNegative(v.Args[0]) { + if b.Func.pass.debug > 0 { + b.Func.Warnl(v.Pos, "Proved %v is unsigned", v.Op) + } + v.Op = unsignedOp[v.Op] + } + fallthrough + case OpLsh8x8, OpLsh8x16, OpLsh8x32, OpLsh8x64, OpLsh16x8, OpLsh16x16, OpLsh16x32, OpLsh16x64, OpLsh32x8, OpLsh32x16, OpLsh32x32, OpLsh32x64, OpLsh64x8, OpLsh64x16, OpLsh64x32, OpLsh64x64, |