File: clobberdead.go

package info (click to toggle)
golang-1.24 1.24.2-2
  • links: PTS, VCS
  • area: main
  • in suites: experimental
  • size: 168,184 kB
  • sloc: asm: 154,896; ansic: 7,009; sh: 2,226; javascript: 1,705; perl: 1,052; python: 421; makefile: 103; cpp: 39; f90: 8; awk: 7; objc: 4
file content (35 lines) | stat: -rw-r--r-- 1,344 bytes parent folder | download | duplicates (14)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
// asmcheck -gcflags=-clobberdead

//go:build amd64 || arm64

// 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.

package codegen

type T [2]*int // contain pointer, not SSA-able (so locals are not registerized)

var p1, p2, p3 T

func F() {
	// 3735936685 is 0xdeaddead. On ARM64 R27 is REGTMP.
	// clobber x, y at entry. not clobber z (stack object).
	// amd64:`MOVL\t\$3735936685, command-line-arguments\.x`, `MOVL\t\$3735936685, command-line-arguments\.y`, -`MOVL\t\$3735936685, command-line-arguments\.z`
	// arm64:`MOVW\tR27, command-line-arguments\.x`, `MOVW\tR27, command-line-arguments\.y`, -`MOVW\tR27, command-line-arguments\.z`
	x, y, z := p1, p2, p3
	addrTaken(&z)
	// x is dead at the call (the value of x is loaded before the CALL), y is not
	// amd64:`MOVL\t\$3735936685, command-line-arguments\.x`, -`MOVL\t\$3735936685, command-line-arguments\.y`
	// arm64:`MOVW\tR27, command-line-arguments\.x`, -`MOVW\tR27, command-line-arguments\.y`
	use(x)
	// amd64:`MOVL\t\$3735936685, command-line-arguments\.x`, `MOVL\t\$3735936685, command-line-arguments\.y`
	// arm64:`MOVW\tR27, command-line-arguments\.x`, `MOVW\tR27, command-line-arguments\.y`
	use(y)
}

//go:noinline
func use(T) {}

//go:noinline
func addrTaken(*T) {}