go/test/phiopt.go
Alexandru Moșoi caef4496fc cmd/compile: convert some Phis into And8.
See discussion at [1]. True value must have a fixed non-zero
representation meaning that a && b can be implemented as a & b.

[1] https://groups.google.com/forum/#!topic/golang-dev/xV0vPuFP9Vg

This change helps with m := a && b, but it's more common to see
if a && b { do something } which is not handled.

Change-Id: Ib6f9ff898a0a8c05d12466e2464e4fe781035394
Reviewed-on: https://go-review.googlesource.com/22313
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2016-04-22 17:22:03 +00:00

108 lines
1.7 KiB
Go

// +build amd64
// errorcheck -0 -d=ssa/phiopt/debug=3
// Copyright 2016 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 main
//go:noinline
func f0(a bool) bool {
x := false
if a {
x = true
} else {
x = false
}
return x // ERROR "converted OpPhi to Copy$"
}
//go:noinline
func f1(a bool) bool {
x := false
if a {
x = false
} else {
x = true
}
return x // ERROR "converted OpPhi to Not$"
}
//go:noinline
func f2(a, b int) bool {
x := true
if a == b {
x = false
}
return x // ERROR "converted OpPhi to Not$"
}
//go:noinline
func f3(a, b int) bool {
x := false
if a == b {
x = true
}
return x // ERROR "converted OpPhi to Copy$"
}
//go:noinline
func f4(a, b bool) bool {
return a || b // ERROR "converted OpPhi to Or8$"
}
//go:noinline
func f5or(a int, b bool) bool {
var x bool
if a == 0 {
x = true
} else {
x = b
}
return x // ERROR "converted OpPhi to Or8$"
}
//go:noinline
func f5and(a int, b bool) bool {
var x bool
if a == 0 {
x = b
} else {
x = false
}
return x // ERROR "converted OpPhi to And8$"
}
//go:noinline
func f6or(a int, b bool) bool {
x := b
if a == 0 {
// f6or has side effects so the OpPhi should not be converted.
x = f6or(a, b)
}
return x
}
//go:noinline
func f6and(a int, b bool) bool {
x := b
if a == 0 {
// f6and has side effects so the OpPhi should not be converted.
x = f6and(a, b)
}
return x
}
//go:noinline
func f7or(a bool, b bool) bool {
return a || b // ERROR "converted OpPhi to Or8$"
}
//go:noinline
func f7and(a bool, b bool) bool {
return a && b // ERROR "converted OpPhi to And8$"
}
func main() {
}