mirror of
https://github.com/golang/go
synced 2024-11-23 19:50:06 -07:00
694025e74f
Fixes #41780. Change-Id: I1dc7c19a9f057650905da3a96214c2ff4abb51be Reviewed-on: https://go-review.googlesource.com/c/go/+/259450 Trust: David Chase <drchase@google.com> Run-TryBot: David Chase <drchase@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
40 lines
845 B
Go
40 lines
845 B
Go
// run
|
|
|
|
// 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.
|
|
|
|
// Checks that conversion of CMP(x,-y) -> CMN(x,y) is only applied in correct context.
|
|
|
|
package main
|
|
|
|
type decimal struct {
|
|
d [8]byte // digits, big-endian representation
|
|
dp int // decimal point
|
|
}
|
|
|
|
var powtab = []int{1, 3, 6, 9, 13, 16, 19, 23, 26}
|
|
|
|
//go:noinline
|
|
func foo(d *decimal) int {
|
|
exp := int(d.d[1])
|
|
if d.dp < 0 || d.dp == 0 && d.d[0] < '5' {
|
|
var n int
|
|
if -d.dp >= len(powtab) {
|
|
n = 27
|
|
} else {
|
|
n = powtab[-d.dp] // incorrect CMP -> CMN substitution causes indexing panic.
|
|
}
|
|
exp += n
|
|
}
|
|
return exp
|
|
}
|
|
|
|
func main() {
|
|
var d decimal
|
|
d.d[0] = '1'
|
|
if foo(&d) != 1 {
|
|
println("FAILURE (though not the one this test was written to catch)")
|
|
}
|
|
}
|