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cmd/compile: fix cmpstring rewrite rule 

We need to ensure that the Select0 lives in the same block as
its argument. Divide up the rule into 2 so that we can put the
parts in the right places.

(This would be simpler if we could use @block syntax mid-rule, but
that feature currently only works at the top level.)

This fixes the ssacheck builder after CL 578835

Change-Id: Id26a01d9fac0684e0b732d35d0f7999f6de07825
Reviewed-on: https://go-review.googlesource.com/c/go/+/580815
Auto-Submit: Keith Randall <khr@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@google.com>
This commit is contained in:
Keith Randall 2024-04-22 10:04:03 -07:00 committed by Gopher Robot
parent 79065f0a5e
commit 9f9dd2bfd8
2 changed files with 56 additions and 32 deletions
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8
src/cmd/compile/internal/ssa/_gen/generic.rules
View File

@ -2799,7 +2799,11 @@
// same memory state can reuse the results of the first call.
// See issue 61725.
// Note that this could pretty easily generalize to any pure function.
(StaticLECall {f} x y m:(SelectN [1] c:(StaticLECall {g} x y mem)))
(SelectN [0] (StaticLECall {f} x y (SelectN [1] c:(StaticLECall {g} x y mem))))
&& isSameCall(f, "runtime.cmpstring")
&& isSameCall(g, "runtime.cmpstring")
=> (MakeResult (SelectN [0] <typ.Int> c) m)
=> @c.Block (SelectN [0] <typ.Int> c)
// If we don't use the result of cmpstring, might as well not call it.
// Note that this could pretty easily generalize to any pure function.
(SelectN [1] c:(StaticLECall {f} _ _ mem)) && c.Uses == 1 && isSameCall(f, "runtime.cmpstring") && clobber(c) => mem

80
src/cmd/compile/internal/ssa/rewritegeneric.go
View File

@ -28081,6 +28081,7 @@ func rewriteValuegeneric_OpSelectN(v *Value) bool {
v_0 := v.Args[0]
b := v.Block
config := b.Func.Config
typ := &b.Func.Config.Types
// match: (SelectN [0] (MakeResult x ___))
// result: x
for {
@ -28439,6 +28440,55 @@ func rewriteValuegeneric_OpSelectN(v *Value) bool {
v.copyOf(newLen)
return true
}
// match: (SelectN [0] (StaticLECall {f} x y (SelectN [1] c:(StaticLECall {g} x y mem))))
// cond: isSameCall(f, "runtime.cmpstring") && isSameCall(g, "runtime.cmpstring")
// result: @c.Block (SelectN [0] <typ.Int> c)
for {
if auxIntToInt64(v.AuxInt) != 0 || v_0.Op != OpStaticLECall || len(v_0.Args) != 3 {
break
}
f := auxToCall(v_0.Aux)
_ = v_0.Args[2]
x := v_0.Args[0]
y := v_0.Args[1]
v_0_2 := v_0.Args[2]
if v_0_2.Op != OpSelectN || auxIntToInt64(v_0_2.AuxInt) != 1 {
break
}
c := v_0_2.Args[0]
if c.Op != OpStaticLECall || len(c.Args) != 3 {
break
}
g := auxToCall(c.Aux)
if x != c.Args[0] || y != c.Args[1] || !(isSameCall(f, "runtime.cmpstring") && isSameCall(g, "runtime.cmpstring")) {
break
}
b = c.Block
v0 := b.NewValue0(v.Pos, OpSelectN, typ.Int)
v.copyOf(v0)
v0.AuxInt = int64ToAuxInt(0)
v0.AddArg(c)
return true
}
// match: (SelectN [1] c:(StaticLECall {f} _ _ mem))
// cond: c.Uses == 1 && isSameCall(f, "runtime.cmpstring") && clobber(c)
// result: mem
for {
if auxIntToInt64(v.AuxInt) != 1 {
break
}
c := v_0
if c.Op != OpStaticLECall || len(c.Args) != 3 {
break
}
f := auxToCall(c.Aux)
mem := c.Args[2]
if !(c.Uses == 1 && isSameCall(f, "runtime.cmpstring") && clobber(c)) {
break
}
v.copyOf(mem)
return true
}
return false
}
func rewriteValuegeneric_OpSignExt16to32(v *Value) bool {
@ -29311,36 +29361,6 @@ func rewriteValuegeneric_OpStaticLECall(v *Value) bool {
v.AddArg2(v0, mem)
return true
}
// match: (StaticLECall {f} x y m:(SelectN [1] c:(StaticLECall {g} x y mem)))
// cond: isSameCall(f, "runtime.cmpstring") && isSameCall(g, "runtime.cmpstring")
// result: (MakeResult (SelectN [0] <typ.Int> c) m)
for {
if len(v.Args) != 3 {
break
}
f := auxToCall(v.Aux)
_ = v.Args[2]
x := v.Args[0]
y := v.Args[1]
m := v.Args[2]
if m.Op != OpSelectN || auxIntToInt64(m.AuxInt) != 1 {
break
}
c := m.Args[0]
if c.Op != OpStaticLECall || len(c.Args) != 3 {
break
}
g := auxToCall(c.Aux)
if x != c.Args[0] || y != c.Args[1] || !(isSameCall(f, "runtime.cmpstring") && isSameCall(g, "runtime.cmpstring")) {
break
}
v.reset(OpMakeResult)
v0 := b.NewValue0(v.Pos, OpSelectN, typ.Int)
v0.AuxInt = int64ToAuxInt(0)
v0.AddArg(c)
v.AddArg2(v0, m)
return true
}
return false
}
func rewriteValuegeneric_OpStore(v *Value) bool {