diff options
| author | Keith Randall <khr@golang.org> | 2022-12-09 10:55:28 -0800 |
|---|---|---|
| committer | Gopher Robot <gobot@golang.org> | 2022-12-09 21:38:33 +0000 |
| commit | e8f78cb60caab4f7ca8d0f4c424f14cc74ab49a4 (patch) | |
| tree | 52de0cc42869d1c08391330c10fca47d0a0c42f4 /src | |
| parent | e76c87b1915cfbd0d4f22c6401987948af18e8c5 (diff) | |
| download | go-e8f78cb60caab4f7ca8d0f4c424f14cc74ab49a4.tar.xz | |
cmd/compile: fix conditional select rule
ARM64 maintains booleans in the low byte of registers. Upper parts
of that register are junk.
This rule is using all 32 bits of a boolean-containing register, which
is wrong. Change the rule to only look at the low bit.
Fixes #57184
Change-Id: Ibbef86b2be859df3d06d993db00e1231c481c428
Reviewed-on: https://go-review.googlesource.com/c/go/+/456556
Auto-Submit: Keith Randall <khr@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
Diffstat (limited to 'src')
| -rw-r--r-- | src/cmd/compile/internal/ssa/_gen/ARM64.rules | 4 | ||||
| -rw-r--r-- | src/cmd/compile/internal/ssa/rewriteARM64.go | 6 |
2 files changed, 5 insertions, 5 deletions
diff --git a/src/cmd/compile/internal/ssa/_gen/ARM64.rules b/src/cmd/compile/internal/ssa/_gen/ARM64.rules index 727204d80a..0c5a2e66a8 100644 --- a/src/cmd/compile/internal/ssa/_gen/ARM64.rules +++ b/src/cmd/compile/internal/ssa/_gen/ARM64.rules @@ -342,9 +342,9 @@ (FCMPD x (FMOVDconst [0])) => (FCMPD0 x) (FCMPD (FMOVDconst [0]) x) => (InvertFlags (FCMPD0 x)) -// CSEL needs a flag-generating argument. Synthesize a CMPW if necessary. +// CSEL needs a flag-generating argument. Synthesize a TSTW if necessary. (CondSelect x y boolval) && flagArg(boolval) != nil => (CSEL [boolval.Op] x y flagArg(boolval)) -(CondSelect x y boolval) && flagArg(boolval) == nil => (CSEL [OpARM64NotEqual] x y (CMPWconst [0] boolval)) +(CondSelect x y boolval) && flagArg(boolval) == nil => (CSEL [OpARM64NotEqual] x y (TSTWconst [1] boolval)) (OffPtr [off] ptr:(SP)) && is32Bit(off) => (MOVDaddr [int32(off)] ptr) (OffPtr [off] ptr) => (ADDconst [off] ptr) diff --git a/src/cmd/compile/internal/ssa/rewriteARM64.go b/src/cmd/compile/internal/ssa/rewriteARM64.go index d7386729e7..e82a49c331 100644 --- a/src/cmd/compile/internal/ssa/rewriteARM64.go +++ b/src/cmd/compile/internal/ssa/rewriteARM64.go @@ -23561,7 +23561,7 @@ func rewriteValueARM64_OpCondSelect(v *Value) bool { } // match: (CondSelect x y boolval) // cond: flagArg(boolval) == nil - // result: (CSEL [OpARM64NotEqual] x y (CMPWconst [0] boolval)) + // result: (CSEL [OpARM64NotEqual] x y (TSTWconst [1] boolval)) for { x := v_0 y := v_1 @@ -23571,8 +23571,8 @@ func rewriteValueARM64_OpCondSelect(v *Value) bool { } v.reset(OpARM64CSEL) v.AuxInt = opToAuxInt(OpARM64NotEqual) - v0 := b.NewValue0(v.Pos, OpARM64CMPWconst, types.TypeFlags) - v0.AuxInt = int32ToAuxInt(0) + v0 := b.NewValue0(v.Pos, OpARM64TSTWconst, types.TypeFlags) + v0.AuxInt = int32ToAuxInt(1) v0.AddArg(boolval) v.AddArg3(x, y, v0) return true |