mirror of
https://github.com/golang/go
synced 2024-11-17 06:54:48 -07:00
25 lines
665 B
Go
25 lines
665 B
Go
|
// asmcheck
|
||
|
|
|
||
|
|
// Copyright 2018 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
|
||
|
|
|
||
|
|
var gx, gy int
|
||
|
|
|
||
|
|
// Test to make sure that (CMPQ (ANDQ x y) [0]) does not get rewritten to
|
||
|
|
// (TESTQ x y) if the ANDQ has other uses. If that rewrite happens, then one
|
||
|
|
// of the args of the ANDQ needs to be saved so it can be used as the arg to TESTQ.
|
||
|
|
func andWithUse(x, y int) int {
|
||
|
|
// Load x,y into registers, so those MOVQ will not appear at the z := x&y line.
|
||
|
|
gx, gy = x, y
|
||
|
|
// amd64:-"MOVQ"
|
||
|
|
z := x & y
|
||
|
|
if z == 0 {
|
||
|
|
return 77
|
||
|
|
}
|
||
|
|
// use z by returning it
|
||
|
|
return z
|
||
|
|
}
|