// run //go: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) }