mirror of
https://github.com/golang/go
synced 2024-11-17 15:24:43 -07:00
c570f0eda2
This shows up in a few crypto functions, and other assorted places. Change-Id: I5a7f4c25ddd4a6499dc295ef693b9fe43d2448ab Reviewed-on: https://go-review.googlesource.com/c/go/+/404057 Run-TryBot: Paul Murphy <murp@ibm.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com> Reviewed-by: David Chase <drchase@google.com> Reviewed-by: Russ Cox <rsc@golang.org>
33 lines
815 B
Go
33 lines
815 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
|
|
}
|
|
|
|
// 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
|
|
}
|