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cmd/compile: remove reduntant Zero rule

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These two rules produce the same output but have opposite
s%16 conditions. Consolidate them into a single rule.

Change-Id: I6daa0e7f7af4a4e59a3125b66b85f59e888586c5
Reviewed-on: https://go-review.googlesource.com/c/go/+/640475
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>
This commit is contained in:
Jakub Ciolek 2025-01-05 11:31:11 +01:00 • committed by Keith Randall
parent bdc2d856a8
commit 46fd6b4e37
2 changed files with 3 additions and 28 deletions
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6
src/cmd/compile/internal/ssa/_gen/AMD64.rules
View file

@ -404,11 +404,7 @@
(MOVQstoreconst [makeValAndOff(0,0)] destptr mem)) (MOVQstoreconst [makeValAndOff(0,0)] destptr mem))
// Adjust zeros to be a multiple of 16 bytes. // Adjust zeros to be a multiple of 16 bytes.
(Zero [s] destptr mem) && s%16 != 0 && s > 16 && s%16 > 8 && config.useSSE => (Zero [s] destptr mem) && s%16 != 0 && s > 16 && config.useSSE =>
(Zero [s-s%16] (OffPtr <destptr.Type> destptr [s%16])
(MOVOstoreconst [makeValAndOff(0,0)] destptr mem))
(Zero [s] destptr mem) && s%16 != 0 && s > 16 && s%16 <= 8 && config.useSSE =>
(Zero [s-s%16] (OffPtr <destptr.Type> destptr [s%16]) (Zero [s-s%16] (OffPtr <destptr.Type> destptr [s%16])
(MOVOstoreconst [makeValAndOff(0,0)] destptr mem)) (MOVOstoreconst [makeValAndOff(0,0)] destptr mem))

25
src/cmd/compile/internal/ssa/rewriteAMD64.go
View file

@ -30270,34 +30270,13 @@ func rewriteValueAMD64_OpZero(v *Value) bool {
return true return true
} }
// match: (Zero [s] destptr mem) // match: (Zero [s] destptr mem)
// cond: s%16 != 0 && s > 16 && s%16 > 8 && config.useSSE // cond: s%16 != 0 && s > 16 && config.useSSE
// result: (Zero [s-s%16] (OffPtr <destptr.Type> destptr [s%16]) (MOVOstoreconst [makeValAndOff(0,0)] destptr mem)) // result: (Zero [s-s%16] (OffPtr <destptr.Type> destptr [s%16]) (MOVOstoreconst [makeValAndOff(0,0)] destptr mem))
for { for {
s := auxIntToInt64(v.AuxInt) s := auxIntToInt64(v.AuxInt)
destptr := v_0 destptr := v_0
mem := v_1 mem := v_1
if !(s%16 != 0 && s > 16 && s%16 > 8 && config.useSSE) { if !(s%16 != 0 && s > 16 && config.useSSE) {
break
}
v.reset(OpZero)
v.AuxInt = int64ToAuxInt(s - s%16)
v0 := b.NewValue0(v.Pos, OpOffPtr, destptr.Type)
v0.AuxInt = int64ToAuxInt(s % 16)
v0.AddArg(destptr)
v1 := b.NewValue0(v.Pos, OpAMD64MOVOstoreconst, types.TypeMem)
v1.AuxInt = valAndOffToAuxInt(makeValAndOff(0, 0))
v1.AddArg2(destptr, mem)
v.AddArg2(v0, v1)
return true
}
// match: (Zero [s] destptr mem)
// cond: s%16 != 0 && s > 16 && s%16 <= 8 && config.useSSE
// result: (Zero [s-s%16] (OffPtr <destptr.Type> destptr [s%16]) (MOVOstoreconst [makeValAndOff(0,0)] destptr mem))
for {
s := auxIntToInt64(v.AuxInt)
destptr := v_0
mem := v_1
if !(s%16 != 0 && s > 16 && s%16 <= 8 && config.useSSE) {
break break
} }
v.reset(OpZero) v.reset(OpZero)