go/test/fixedbugs/issue32680.go
David Chase 769fda2d51 cmd/compile: add necessary operand to mergePoint in rewrite rules
A missing operand to mergePoint caused lower to place values
in the wrong blocks.

Includes test, belt+suspenders to do both ssa check and verify
the output (was is how the bug was originally observed).

The fixed bug here is very likely present in Go versions
1.9-1.12 on amd64 and s390x

Fixes #32680.

Change-Id: I63e702c4c40602cb795ef71b1691eb704d38ccc7
Reviewed-on: https://go-review.googlesource.com/c/go/+/183059
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-06-20 16:56:47 +00:00

24 lines
687 B
Go

// run -gcflags=-d=ssa/check/on
// Copyright 2019 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.
// As of 2019-06, bug affects/ed amd64 and s390x.
package main
var foo = []byte{105, 57, 172, 152}
func main() {
for i := 0; i < len(foo); i += 4 {
// Requires inlining and non-constant i
// Note the bug/fix also apply to different widths, but was unable to reproduce for those.
println(readLittleEndian32_2(foo[i], foo[i+1], foo[i+2], foo[i+3]))
}
}
func readLittleEndian32_2(a, b, c, d byte) uint32 {
return uint32(a) | (uint32(b) << 8) | (uint32(c) << 16) | (uint32(d) << 24)
}