math: improve sqrt for ppc64le,ppc64
The existing implementation uses code written in Go to
implement Sqrt; this adds the assembler to use the sqrt
instruction for Power and makes the necessary changes to
allow it to be inlined.
The following tests showed this relative improvement:
benchmark delta
BenchmarkSqrt -97.91%
BenchmarkSqrtIndirect -96.65%
BenchmarkSqrtGo -35.93%
BenchmarkSqrtPrime -96.94%
Fixes #14349
Change-Id: I8074f4dc63486e756587564ceb320aca300bf5fa
Reviewed-on: https://go-review.googlesource.com/19515
Reviewed-by: Minux Ma <minux@golang.org>
diff --git a/src/cmd/compile/internal/gc/walk.go b/src/cmd/compile/internal/gc/walk.go
index 30c1ecc04..531ddc3 100644
--- a/src/cmd/compile/internal/gc/walk.go
+++ b/src/cmd/compile/internal/gc/walk.go
@@ -677,7 +677,7 @@
if n.Left.Op == ONAME && n.Left.Sym.Name == "Sqrt" && n.Left.Sym.Pkg.Path == "math" {
switch Thearch.Thechar {
- case '5', '6', '7':
+ case '5', '6', '7', '9':
n.Op = OSQRT
n.Left = n.List.First()
n.List.Set(nil)
