mirror of
https://github.com/golang/go
synced 2024-11-27 05:31:31 -07:00
46 lines
983 B
Go
46 lines
983 B
Go
|
// run
|
||
|
|
|
||
|
|
//go:build !wasm
|
||
|
|
// +build !wasm
|
||
|
|
|
||
|
|
// Copyright 2021 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.
|
||
|
|
|
||
|
|
// wasm is excluded because the compiler chatter about register abi pragma ends up
|
||
|
|
// on stdout, and causes the expected output to not match.
|
||
|
|
|
||
|
|
package main
|
||
|
|
|
||
|
|
import (
|
||
|
|
"fmt"
|
||
|
|
)
|
||
|
|
|
||
|
|
var sink int = 3
|
||
|
|
|
||
|
|
//go:registerparams
|
||
|
|
//go:noinline
|
||
|
|
func F(a, b, c, d, e, f *int) {
|
||
|
|
G(f, e, d, c, b, a)
|
||
|
|
sink += *a // *a == 6 after swapping in G
|
||
|
|
}
|
||
|
|
|
||
|
|
//go:registerparams
|
||
|
|
//go:noinline
|
||
|
|
func G(a, b, c, d, e, f *int) {
|
||
|
|
var scratch [1000 * 100]int
|
||
|
|
scratch[*a] = *f // scratch[6] = 1
|
||
|
|
fmt.Println(*a, *b, *c, *d, *e, *f) // Forces it to spill b
|
||
|
|
sink = scratch[*b+1] // scratch[5+1] == 1
|
||
|
|
*f, *a = *a, *f
|
||
|
|
*e, *b = *b, *e
|
||
|
|
*d, *c = *c, *d
|
||
|
|
}
|
||
|
|
|
||
|
|
func main() {
|
||
|
|
a, b, c, d, e, f := 1, 2, 3, 4, 5, 6
|
||
|
|
F(&a, &b, &c, &d, &e, &f)
|
||
|
|
fmt.Println(a, b, c, d, e, f)
|
||
|
|
fmt.Println(sink)
|
||
|
|
}
|