cmd/compile: optimize x & 1 != 0 to x & 1 on amd64

Triggers a handful of times in std+cmd.

Change-Id: I9bb8ce9a5f8bae2547cb61157cd8f256e1b63e76
Reviewed-on: https://go-review.googlesource.com/c/go/+/229602
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

1 files changed, 33 insertions, 0 deletions

diff --git a/test/codegen/bool.go b/test/codegen/bool.go
new file mode 100644
index 00000000000..929b1b49b9b
--- /dev/null
+++ b/test/codegen/bool.go
@@ -0,0 +1,33 @@
+// asmcheck
+
+// Copyright 2020 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
+
+// This file contains codegen tests related to boolean simplifications/optimizations.
+
+func convertNeq0B(x uint8, c bool) bool {
+	// amd64:"ANDL\t[$]1",-"SETNE"
+	b := x&1 != 0
+	return c && b
+}
+
+func convertNeq0W(x uint16, c bool) bool {
+	// amd64:"ANDL\t[$]1",-"SETNE"
+	b := x&1 != 0
+	return c && b
+}
+
+func convertNeq0L(x uint32, c bool) bool {
+	// amd64:"ANDL\t[$]1",-"SETB"
+	b := x&1 != 0
+	return c && b
+}
+
+func convertNeq0Q(x uint64, c bool) bool {
+	// amd64:"ANDQ\t[$]1",-"SETB"
+	b := x&1 != 0
+	return c && b
+}