mirror of
https://github.com/golang/go
synced 2024-11-14 07:10:21 -07:00
ffb20631fc
Duffcopy now uses X0, as of 5cf281a. Teach the peephole
optimizer that duffcopy clobbers X0 so that it does not
rename registers use X0 across the duffcopy instruction.
Fixes #13171
Change-Id: I389cbf1982cb6eb2f51e6152ac96736a8589f085
Reviewed-on: https://go-review.googlesource.com/16715
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
Reviewed-by: Ilya Tocar <ilya.tocar@intel.com>
35 lines
589 B
Go
35 lines
589 B
Go
// run
|
|
|
|
// Copyright 2015 The Go Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package main
|
|
|
|
// Make sure the compiler knows that DUFFCOPY clobbers X0
|
|
|
|
import "fmt"
|
|
|
|
//go:noinline
|
|
func f(x float64) float64 {
|
|
// y is allocated to X0
|
|
y := x + 5
|
|
// marshals z before y. Marshalling z
|
|
// calls DUFFCOPY.
|
|
return g(z, y)
|
|
}
|
|
|
|
//go:noinline
|
|
func g(b [64]byte, y float64) float64 {
|
|
return y
|
|
}
|
|
|
|
var z [64]byte
|
|
|
|
func main() {
|
|
got := f(5)
|
|
if got != 10 {
|
|
panic(fmt.Sprintf("want 10, got %f", got))
|
|
}
|
|
}
|