diff options
| author | Joel Sing <joel@sing.id.au> | 2022-08-30 06:32:09 +1000 |
|---|---|---|
| committer | Joel Sing <joel@sing.id.au> | 2022-09-07 05:38:50 +0000 |
| commit | b6a6847b2f33dc8fb231c78cc4d807eaf10a133a (patch) | |
| tree | 7471f9dff75d3b960ec853f0cf8b707c04761b00 /src | |
| parent | c011270fa56303c0f16a8cfa9b37f37f470a45bb (diff) | |
| download | go-b6a6847b2f33dc8fb231c78cc4d807eaf10a133a.tar.xz | |
cmd/compile: avoid zero extension after properly typed atomic operation on riscv64
LoweredAtomicLoad8 is implemented using MOVBU, hence it is already zero
extended. LoweredAtomicCas32 and LoweredAtomicCas64 return a properly
typed boolean.
Change-Id: Ie0acbaa19403d59c7e5f76d060cc13ee51eb7834
Reviewed-on: https://go-review.googlesource.com/c/go/+/428214
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Joel Sing <joel@sing.id.au>
Diffstat (limited to 'src')
| -rw-r--r-- | src/cmd/compile/internal/ssa/gen/RISCV64.rules | 5 | ||||
| -rw-r--r-- | src/cmd/compile/internal/ssa/rewriteRISCV64.go | 45 |
2 files changed, 50 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/ssa/gen/RISCV64.rules b/src/cmd/compile/internal/ssa/gen/RISCV64.rules index 0207fb45d6..385f004b22 100644 --- a/src/cmd/compile/internal/ssa/gen/RISCV64.rules +++ b/src/cmd/compile/internal/ssa/gen/RISCV64.rules @@ -686,6 +686,11 @@ (MOVWUreg x:(MOVHUload _ _)) => (MOVDreg x) (MOVWUreg x:(MOVWUload _ _)) => (MOVDreg x) +// Avoid zero extension after properly typed atomic operation. +(MOVBUreg x:(Select0 (LoweredAtomicLoad8 _ _))) => (MOVDreg x) +(MOVBUreg x:(Select0 (LoweredAtomicCas32 _ _ _ _))) => (MOVDreg x) +(MOVBUreg x:(Select0 (LoweredAtomicCas64 _ _ _ _))) => (MOVDreg x) + // Fold double extensions. (MOVBreg x:(MOVBreg _)) => (MOVDreg x) (MOVHreg x:(MOVBreg _)) => (MOVDreg x) diff --git a/src/cmd/compile/internal/ssa/rewriteRISCV64.go b/src/cmd/compile/internal/ssa/rewriteRISCV64.go index 908456b0aa..ac0770639e 100644 --- a/src/cmd/compile/internal/ssa/rewriteRISCV64.go +++ b/src/cmd/compile/internal/ssa/rewriteRISCV64.go @@ -3609,6 +3609,51 @@ func rewriteValueRISCV64_OpRISCV64MOVBUreg(v *Value) bool { v.AddArg(x) return true } + // match: (MOVBUreg x:(Select0 (LoweredAtomicLoad8 _ _))) + // result: (MOVDreg x) + for { + x := v_0 + if x.Op != OpSelect0 { + break + } + x_0 := x.Args[0] + if x_0.Op != OpRISCV64LoweredAtomicLoad8 { + break + } + v.reset(OpRISCV64MOVDreg) + v.AddArg(x) + return true + } + // match: (MOVBUreg x:(Select0 (LoweredAtomicCas32 _ _ _ _))) + // result: (MOVDreg x) + for { + x := v_0 + if x.Op != OpSelect0 { + break + } + x_0 := x.Args[0] + if x_0.Op != OpRISCV64LoweredAtomicCas32 { + break + } + v.reset(OpRISCV64MOVDreg) + v.AddArg(x) + return true + } + // match: (MOVBUreg x:(Select0 (LoweredAtomicCas64 _ _ _ _))) + // result: (MOVDreg x) + for { + x := v_0 + if x.Op != OpSelect0 { + break + } + x_0 := x.Args[0] + if x_0.Op != OpRISCV64LoweredAtomicCas64 { + break + } + v.reset(OpRISCV64MOVDreg) + v.AddArg(x) + return true + } // match: (MOVBUreg x:(MOVBUreg _)) // result: (MOVDreg x) for { |