go/test/fixedbugs/issue50854.go
David Chase b7b44b3173 cmd/compile: remove incorrect arm,arm64 CMP->CMN transformations
These can go wrong when one of the operands is the minimum integer value.

Fixes #50854.

Change-Id: I238fe284f60c7ee5aeb9dc9a18e8b1578cdb77d0
Reviewed-on: https://go-review.googlesource.com/c/go/+/381318
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Trust: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
2022-01-27 19:52:52 +00:00

39 lines
890 B
Go

// run
// Copyright 2022 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
// This checks for incorrect application of CMP(-x,y) -> CMN(x,y) in arm and arm64
//go:noinline
func f(p int64, x, y int64) bool { return -x <= p && p <= y }
//go:noinline
func g(p int32, x, y int32) bool { return -x <= p && p <= y }
// There are some more complicated patterns involving compares and shifts, try to trigger those.
//go:noinline
func h(p int64, x, y int64) bool { return -(x<<1) <= p && p <= y }
//go:noinline
func k(p int32, x, y int32) bool { return -(1<<x) <= p && p <= y }
//go:noinline
func check(b bool) {
if b {
return
}
panic("FAILURE")
}
func main() {
check(f(1, -1<<63, 1<<63-1))
check(g(1, -1<<31, 1<<31-1))
check(h(1, -1<<62, 1<<63-1))
check(k(1, 31, 1<<31-1))
}