mirror of
https://github.com/golang/go
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45 lines
967 B
Go
45 lines
967 B
Go
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// run
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//go:build !wasm
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// Copyright 2021 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// wasm is excluded because the compiler chatter about register abi pragma ends up
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// on stdout, and causes the expected output to not match.
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package main
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import (
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"fmt"
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)
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var sink int = 3
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//go:registerparams
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//go:noinline
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func F(a, b, c, d, e, f *int) {
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G(f, e, d, c, b, a)
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sink += *a // *a == 6 after swapping in G
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}
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//go:registerparams
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//go:noinline
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func G(a, b, c, d, e, f *int) {
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var scratch [1000 * 100]int
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scratch[*a] = *f // scratch[6] = 1
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fmt.Println(*a, *b, *c, *d, *e, *f) // Forces it to spill b
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sink = scratch[*b+1] // scratch[5+1] == 1
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*f, *a = *a, *f
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*e, *b = *b, *e
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*d, *c = *c, *d
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}
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func main() {
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a, b, c, d, e, f := 1, 2, 3, 4, 5, 6
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F(&a, &b, &c, &d, &e, &f)
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fmt.Println(a, b, c, d, e, f)
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fmt.Println(sink)
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}
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