cmd/compile: using a single Store op for non-pointer non-skip store

This makes fewer Values around until decomposing, reducing
allocation in compiler.

name       old alloc/op    new alloc/op    delta
Template      41.4MB ± 0%     40.8MB ± 0%  -1.29%  (p=0.000 n=10+10)
Unicode       30.3MB ± 0%     30.2MB ± 0%  -0.24%  (p=0.000 n=10+10)
GoTypes        118MB ± 0%      115MB ± 0%  -2.23%  (p=0.000 n=10+10)
Compiler       505MB ± 0%      493MB ± 0%  -2.47%  (p=0.000 n=10+10)
SSA            881MB ± 0%      872MB ± 0%  -1.03%  (p=0.000 n=10+10)

name       old allocs/op   new allocs/op   delta
Template        401k ± 1%       400k ± 1%    ~     (p=0.631 n=10+10)
Unicode         321k ± 0%       321k ± 1%    ~     (p=0.684 n=10+10)
GoTypes        1.18M ± 0%      1.17M ± 0%  -0.34%  (p=0.000 n=10+10)
Compiler       4.63M ± 0%      4.61M ± 0%  -0.43%  (p=0.000 n=10+10)
SSA            7.83M ± 0%      7.82M ± 0%  -0.13%  (p=0.000 n=10+10)

Change-Id: I8f736396294444248a439bd4c90be1357024ce88
Reviewed-on: https://go-review.googlesource.com/38294
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
This commit is contained in:
Cherry Zhang 2017-03-17 11:53:24 -04:00
parent 2cdb7f118a
commit ce584e516e
2 changed files with 11 additions and 3 deletions

View file

@ -19,7 +19,7 @@ func needwb(v *Value) bool {
if !t.HasPointer() {
return false
}
if isStackAddr(v.Args[0]) {
if IsStackAddr(v.Args[0]) {
return false // write on stack doesn't need write barrier
}
return true
@ -316,8 +316,8 @@ func round(o int64, r int64) int64 {
return (o + r - 1) &^ (r - 1)
}
// isStackAddr returns whether v is known to be an address of a stack slot
func isStackAddr(v *Value) bool {
// IsStackAddr returns whether v is known to be an address of a stack slot
func IsStackAddr(v *Value) bool {
for v.Op == OpOffPtr || v.Op == OpAddPtr || v.Op == OpPtrIndex || v.Op == OpCopy {
v = v.Args[0]
}