diff options
| author | Julian Zhu <jz531210@gmail.com> | 2025-05-17 00:27:37 +0800 |
|---|---|---|
| committer | Keith Randall <khr@golang.org> | 2025-05-19 11:27:35 -0700 |
| commit | d52679006c8e08875fac92aca1f723fce488d0d2 (patch) | |
| tree | 2690b36fee4276e7b13bedfb4d57c9a5c9a6f20e /src | |
| parent | 972639fc4cf257f04f9690e63bea7cd729b3edd2 (diff) | |
| download | go-d52679006c8e08875fac92aca1f723fce488d0d2.tar.xz | |
cmd/compile: fold negation into addition/subtraction on mipsx
Fold negation into addition/subtraction and avoid double negation.
file before after Δ %
addr2line 3742022 3741986 -36 -0.001%
asm 6668616 6668628 +12 +0.000%
buildid 3583786 3583630 -156 -0.004%
cgo 6020370 6019634 -736 -0.012%
compile 29416016 29417336 +1320 +0.004%
cover 6801903 6801675 -228 -0.003%
dist 4485916 4485816 -100 -0.002%
doc 10652787 10652251 -536 -0.005%
fix 4115988 4115560 -428 -0.010%
link 9002328 9001616 -712 -0.008%
nm 3733148 3732780 -368 -0.010%
objdump 6163292 6163068 -224 -0.004%
pack 2944768 2944604 -164 -0.006%
pprof 18909973 18908773 -1200 -0.006%
test2json 3394662 3394778 +116 +0.003%
trace 17350911 17349751 -1160 -0.007%
vet 10077727 10077527 -200 -0.002%
go 19118769 19118609 -160 -0.001%
total 166182982 166178022 -4960 -0.003%
Change-Id: Id55698800fd70f3cb2ff48393584456b87208921
Reviewed-on: https://go-review.googlesource.com/c/go/+/673556
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Diffstat (limited to 'src')
| -rw-r--r-- | src/cmd/compile/internal/ssa/_gen/MIPS.rules | 3 | ||||
| -rw-r--r-- | src/cmd/compile/internal/ssa/rewriteMIPS.go | 34 |
2 files changed, 37 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/ssa/_gen/MIPS.rules b/src/cmd/compile/internal/ssa/_gen/MIPS.rules index 4471763462..a4899ac24d 100644 --- a/src/cmd/compile/internal/ssa/_gen/MIPS.rules +++ b/src/cmd/compile/internal/ssa/_gen/MIPS.rules @@ -614,11 +614,14 @@ // generic simplifications (ADD x (NEG y)) => (SUB x y) +(SUB x (NEG y)) => (ADD x y) (SUB x x) => (MOVWconst [0]) (SUB (MOVWconst [0]) x) => (NEG x) (AND x x) => x (OR x x) => x (XOR x x) => (MOVWconst [0]) +(NEG (SUB x y)) => (SUB y x) +(NEG (NEG x)) => x // miscellaneous patterns generated by dec64 (AND (SGTUconst [1] x) (SGTUconst [1] y)) => (SGTUconst [1] (OR <x.Type> x y)) diff --git a/src/cmd/compile/internal/ssa/rewriteMIPS.go b/src/cmd/compile/internal/ssa/rewriteMIPS.go index 1bc2cb6e6d..fe24f0fd0f 100644 --- a/src/cmd/compile/internal/ssa/rewriteMIPS.go +++ b/src/cmd/compile/internal/ssa/rewriteMIPS.go @@ -4096,6 +4096,28 @@ func rewriteValueMIPS_OpMIPSMUL(v *Value) bool { } func rewriteValueMIPS_OpMIPSNEG(v *Value) bool { v_0 := v.Args[0] + // match: (NEG (SUB x y)) + // result: (SUB y x) + for { + if v_0.Op != OpMIPSSUB { + break + } + y := v_0.Args[1] + x := v_0.Args[0] + v.reset(OpMIPSSUB) + v.AddArg2(y, x) + return true + } + // match: (NEG (NEG x)) + // result: x + for { + if v_0.Op != OpMIPSNEG { + break + } + x := v_0.Args[0] + v.copyOf(x) + return true + } // match: (NEG (MOVWconst [c])) // result: (MOVWconst [-c]) for { @@ -4748,6 +4770,18 @@ func rewriteValueMIPS_OpMIPSSUB(v *Value) bool { v.AddArg(x) return true } + // match: (SUB x (NEG y)) + // result: (ADD x y) + for { + x := v_0 + if v_1.Op != OpMIPSNEG { + break + } + y := v_1.Args[0] + v.reset(OpMIPSADD) + v.AddArg2(x, y) + return true + } // match: (SUB x x) // result: (MOVWconst [0]) for { |