cmd/compile: don’t generate a new Node for convas
This removes about 3% of the Nodes allocated
while compiling std+cmd.
Passes toolstash -cmp.
name old time/op new time/op delta
Template 320ms ± 3% 316ms ± 5% ~ (p=0.063 n=21+23)
Unicode 162ms ± 9% 161ms ± 6% ~ (p=0.788 n=25+25)
GoTypes 1.03s ± 4% 1.03s ± 4% ~ (p=0.929 n=24+25)
Compiler 4.99s ± 3% 4.95s ± 2% -0.84% (p=0.011 n=25+23)
MakeBash 40.3s ± 1% 40.3s ± 1% ~ (p=0.468 n=24+24)
name old alloc/op new alloc/op delta
Template 57.3MB ± 0% 57.0MB ± 0% -0.51% (p=0.000 n=25+23)
Unicode 41.1MB ± 0% 41.0MB ± 0% -0.27% (p=0.000 n=25+24)
GoTypes 191MB ± 0% 190MB ± 0% -0.46% (p=0.000 n=25+25)
Compiler 839MB ± 0% 834MB ± 0% -0.62% (p=0.000 n=24+24)
name old allocs/op new allocs/op delta
Template 500k ± 0% 498k ± 0% -0.42% (p=0.000 n=25+25)
Unicode 400k ± 0% 399k ± 0% -0.22% (p=0.000 n=24+25)
GoTypes 1.50M ± 0% 1.49M ± 0% -0.41% (p=0.000 n=23+25)
Compiler 6.04M ± 0% 6.00M ± 0% -0.59% (p=0.000 n=25+25)
Change-Id: I7d3f177d1ab4a75a4c047fa465f2eee38747603f
Reviewed-on: https://go-review.googlesource.com/21178
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/src/cmd/compile/internal/gc/walk.go b/src/cmd/compile/internal/gc/walk.go
index 9862c24..6d077d5 100644
--- a/src/cmd/compile/internal/gc/walk.go
+++ b/src/cmd/compile/internal/gc/walk.go
@@ -774,9 +774,9 @@
}
if n.Left != nil && n.Right != nil {
- r := convas(Nod(OAS, n.Left, n.Right), init)
- r.Dodata = n.Dodata
- n = r
+ dd := n.Dodata
+ n = convas(n, init)
+ n.Dodata = dd
n = applywritebarrier(n)
}
