diff options
| author | Lynn Boger <laboger@linux.vnet.ibm.com> | 2021-10-05 10:22:47 -0500 |
|---|---|---|
| committer | Lynn Boger <laboger@linux.vnet.ibm.com> | 2021-10-06 12:54:11 +0000 |
| commit | ce72766a02a4be127a26e95fbd62c4b4bb906e91 (patch) | |
| tree | ad9f823d8fad9950ca58bee70326f2493486aba6 | |
| parent | 72c52bfbe2f72fbcacc865e18f132366bdd2effa (diff) | |
| download | go-ce72766a02a4be127a26e95fbd62c4b4bb906e91.tar.xz | |
cmd/compile: improve PPC64 rules for AtomicLoad{8,32}
This adds a rule to avoid the zero extension after an AtomicLoad8
or AtomicLoad32 since the atomic load has already filled it with
zeros. This eliminates an instruction in a high use block in findObject
and the AtomicLoad8 appears many times within runtime.
Change-Id: I7e684bf73d3812110bd371e05b1aa44fa235fc9b
Reviewed-on: https://go-review.googlesource.com/c/go/+/354029
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Trust: Lynn Boger <laboger@linux.vnet.ibm.com>
| -rw-r--r-- | src/cmd/compile/internal/ssa/gen/PPC64.rules | 2 | ||||
| -rw-r--r-- | src/cmd/compile/internal/ssa/rewritePPC64.go | 28 |
2 files changed, 30 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/ssa/gen/PPC64.rules b/src/cmd/compile/internal/ssa/gen/PPC64.rules index 4c766df4b3..8e42bae215 100644 --- a/src/cmd/compile/internal/ssa/gen/PPC64.rules +++ b/src/cmd/compile/internal/ssa/gen/PPC64.rules @@ -1019,6 +1019,8 @@ (MOVWZreg x:(MOVWZloadidx _ _ _)) => x (MOVWreg x:(MOVWload _ _)) => x (MOVWreg x:(MOVWloadidx _ _ _)) => x +(MOVBZreg x:(Select0 (LoweredAtomicLoad8 _ _))) => x +(MOVWZreg x:(Select0 (LoweredAtomicLoad32 _ _))) => x // don't extend if argument is already extended (MOVBreg x:(Arg <t>)) && is8BitInt(t) && isSigned(t) => x diff --git a/src/cmd/compile/internal/ssa/rewritePPC64.go b/src/cmd/compile/internal/ssa/rewritePPC64.go index b278a4cb44..1e6624e906 100644 --- a/src/cmd/compile/internal/ssa/rewritePPC64.go +++ b/src/cmd/compile/internal/ssa/rewritePPC64.go @@ -7093,6 +7093,20 @@ func rewriteValuePPC64_OpPPC64MOVBZreg(v *Value) bool { v.copyOf(x) return true } + // match: (MOVBZreg x:(Select0 (LoweredAtomicLoad8 _ _))) + // result: x + for { + x := v_0 + if x.Op != OpSelect0 { + break + } + x_0 := x.Args[0] + if x_0.Op != OpPPC64LoweredAtomicLoad8 { + break + } + v.copyOf(x) + return true + } // match: (MOVBZreg x:(Arg <t>)) // cond: is8BitInt(t) && !isSigned(t) // result: x @@ -10549,6 +10563,20 @@ func rewriteValuePPC64_OpPPC64MOVWZreg(v *Value) bool { v.copyOf(x) return true } + // match: (MOVWZreg x:(Select0 (LoweredAtomicLoad32 _ _))) + // result: x + for { + x := v_0 + if x.Op != OpSelect0 { + break + } + x_0 := x.Args[0] + if x_0.Op != OpPPC64LoweredAtomicLoad32 { + break + } + v.copyOf(x) + return true + } // match: (MOVWZreg x:(Arg <t>)) // cond: (is8BitInt(t) || is16BitInt(t) || is32BitInt(t)) && !isSigned(t) // result: x |