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cmd/compile/internal/ssa: combine more const stores

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We already combine const stores up-to MOVQstoreconst.
Combine 2 64-bit stores of const zero into 1 sse store of 128-bit zero.

Shaves significant (>1%) amount of code from go tool:
/localdisk/itocar/golang/bin/go 10334877
go_old 10388125 [53248 bytes]

global text (code) = 51041 bytes (1.343944%)
read-only data = 663 bytes (0.039617%)
Total difference 51704 bytes (0.873981%)

Change-Id: I7bc40968023c3a69f379b10fbb433cdb11364f1b
Reviewed-on: https://go-review.googlesource.com/56250
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Giovanni Bajo <rasky@develer.com>
Reviewed-by: Keith Randall <khr@golang.org>
This commit is contained in:
Ilya Tocar 2017-08-16 14:01:48 -05:00
parent b5dab2b9d9
commit da34ddf24b
3 changed files with 45 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
src/cmd/compile/internal/gc/asm_test.go
View File

@ -362,7 +362,7 @@ var linuxAMD64Tests = []*asmTest{
*t = T1{}
}
`,
[]string{"\tMOVQ\t\\$0, \\(.*\\)", "\tMOVQ\t\\$0, 8\\(.*\\)", "\tMOVQ\t\\$0, 16\\(.*\\)"},
[]string{"\tXORPS\tX., X", "\tMOVUPS\tX., \\(.*\\)", "\tMOVQ\t\\$0, 16\\(.*\\)"},
},
// SSA-able composite literal initialization. Issue 18872.
{
@ -387,7 +387,7 @@ var linuxAMD64Tests = []*asmTest{
*t = T2{}
}
`,
[]string{"\tMOVQ\t\\$0, \\(.*\\)", "\tMOVQ\t\\$0, 8\\(.*\\)", "\tMOVQ\t\\$0, 16\\(.*\\)", "\tCALL\truntime\\.writebarrierptr\\(SB\\)"},
[]string{"\tXORPS\tX., X", "\tMOVUPS\tX., \\(.*\\)", "\tMOVQ\t\\$0, 16\\(.*\\)", "\tCALL\truntime\\.writebarrierptr\\(SB\\)"},
},
// Rotate tests
{

7
src/cmd/compile/internal/ssa/gen/AMD64.rules
View File

@ -2204,6 +2204,13 @@
&& ValAndOff(a).Off() + 4 == ValAndOff(c).Off()
&& clobber(x)
-> (MOVQstore [ValAndOff(a).Off()] {s} p (MOVQconst [ValAndOff(a).Val()&0xffffffff | ValAndOff(c).Val()<<32]) mem)
(MOVQstoreconst [c] {s} p x:(MOVQstoreconst [c2] {s} p mem))
&& x.Uses == 1
&& ValAndOff(c2).Off() + 8 == ValAndOff(c).Off()
&& ValAndOff(c).Val() == 0
&& ValAndOff(c2).Val() == 0
&& clobber(x)
-> (MOVOstore [ValAndOff(c2).Off()] {s} p (MOVOconst [0]) mem)
(MOVBstoreconstidx1 [c] {s} p i x:(MOVBstoreconstidx1 [a] {s} p i mem))
&& x.Uses == 1

36
src/cmd/compile/internal/ssa/rewriteAMD64.go
View File

@ -9009,6 +9009,8 @@ func rewriteValueAMD64_OpAMD64MOVQstore_0(v *Value) bool {
return false
}
func rewriteValueAMD64_OpAMD64MOVQstoreconst_0(v *Value) bool {
b := v.Block
_ = b
// match: (MOVQstoreconst [sc] {s} (ADDQconst [off] ptr) mem)
// cond: ValAndOff(sc).canAdd(off)
// result: (MOVQstoreconst [ValAndOff(sc).add(off)] {s} ptr mem)
@ -9137,6 +9139,40 @@ func rewriteValueAMD64_OpAMD64MOVQstoreconst_0(v *Value) bool {
v.AddArg(mem)
return true
}
// match: (MOVQstoreconst [c] {s} p x:(MOVQstoreconst [c2] {s} p mem))
// cond: x.Uses == 1 && ValAndOff(c2).Off() + 8 == ValAndOff(c).Off() && ValAndOff(c).Val() == 0 && ValAndOff(c2).Val() == 0 && clobber(x)
// result: (MOVOstore [ValAndOff(c2).Off()] {s} p (MOVOconst [0]) mem)
for {
c := v.AuxInt
s := v.Aux
_ = v.Args[1]
p := v.Args[0]
x := v.Args[1]
if x.Op != OpAMD64MOVQstoreconst {
break
}
c2 := x.AuxInt
if x.Aux != s {
break
}
_ = x.Args[1]
if p != x.Args[0] {
break
}
mem := x.Args[1]
if !(x.Uses == 1 && ValAndOff(c2).Off()+8 == ValAndOff(c).Off() && ValAndOff(c).Val() == 0 && ValAndOff(c2).Val() == 0 && clobber(x)) {
break
}
v.reset(OpAMD64MOVOstore)
v.AuxInt = ValAndOff(c2).Off()
v.Aux = s
v.AddArg(p)
v0 := b.NewValue0(v.Pos, OpAMD64MOVOconst, types.TypeInt128)
v0.AuxInt = 0
v.AddArg(v0)
v.AddArg(mem)
return true
}
// match: (MOVQstoreconst [sc] {sym1} (LEAL [off] {sym2} ptr) mem)
// cond: canMergeSym(sym1, sym2) && ValAndOff(sc).canAdd(off)
// result: (MOVQstoreconst [ValAndOff(sc).add(off)] {mergeSym(sym1, sym2)} ptr mem)