golang logic 代码
文件路径:/test/codegen/logic.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
}
/ Verify (OR x (NOT y)) rewrites to (ORN x y) where supported
func ornot(x, y int) int {
/ ppc64:"ORN"
/ ppc64le:"ORN"
z := x | ^y
return z
}