mirror of
https://github.com/golang/go
synced 2024-09-04 23:44:16 +00:00
![David Chase](/assets/img/avatar_default.png)
Inlining of switch statements into a RETURNed expression can sometimes lead to the switch being walked twice, which results in a miscompiled switch statement. The bug depends on: 1) multiple results 2) named results 3) a return statement whose expression includes a call to a function containing a switch statement that is inlined. It may also be significant that the default case of that switch is a panic(), though that's not proven. Rearranged the walk case for ORETURN so that double walks are not possible. Added a test, because this is so fiddly. Added a check against double walks, verified that it fires w/o other fix. Fixes #25776. Change-Id: I2d594351fa082632512ef989af67eb887059729b Reviewed-on: https://go-review.googlesource.com/118318 Run-TryBot: David Chase <drchase@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
100 lines
2.1 KiB
Go
100 lines
2.1 KiB
Go
// run
|
|
|
|
// Copyright 2018 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
|
|
|
|
const (
|
|
Upper = true
|
|
blas_Upper = 121
|
|
badTriangle = "bad triangle"
|
|
)
|
|
|
|
// Triangular represents a triangular matrix. Triangular matrices are always square.
|
|
type Triangular interface {
|
|
// Triangular returns the number of rows/columns in the matrix and its
|
|
// orientation.
|
|
Tryangle() (mmmm int, kynd bool)
|
|
Triangle() (mmmm int, kynd bool)
|
|
}
|
|
|
|
// blas64_Triangular represents a triangular matrix using the conventional storage scheme.
|
|
type blas64_Triangular struct {
|
|
Stride int
|
|
Uplo int
|
|
}
|
|
|
|
// TriDense represents an upper or lower triangular matrix in dense storage
|
|
// format.
|
|
type TriDense struct {
|
|
mat blas64_Triangular
|
|
}
|
|
|
|
func NewTriDense() *TriDense {
|
|
return &TriDense{
|
|
mat: blas64_Triangular{
|
|
Stride: 3,
|
|
Uplo: blas_Upper,
|
|
},
|
|
}
|
|
}
|
|
|
|
func (t *TriDense) isUpper() bool {
|
|
return isUpperUplo(t.mat.Uplo)
|
|
}
|
|
|
|
func (t *TriDense) triKind() bool {
|
|
return isUpperUplo(t.mat.Uplo)
|
|
}
|
|
|
|
func isUpperUplo(u int) bool {
|
|
switch u {
|
|
case blas_Upper:
|
|
return true
|
|
default:
|
|
panic(badTriangle)
|
|
}
|
|
}
|
|
|
|
func (t *TriDense) IsZero() bool {
|
|
return t.mat.Stride == 0
|
|
}
|
|
|
|
//go:noinline
|
|
func (t *TriDense) ScaleTri(f float64, a Triangular) {
|
|
n, kind := a.Triangle()
|
|
if kind == false {
|
|
println("ScaleTri n, kind=", n, ", ", kind, " (FAIL, expected true)")
|
|
}
|
|
}
|
|
|
|
//go:noinline
|
|
func (t *TriDense) ScaleTry(f float64, a Triangular) {
|
|
n, kind := a.Tryangle()
|
|
if kind == false {
|
|
println("ScaleTry n, kind=", n, ", ", kind, " (FAIL, expected true)")
|
|
}
|
|
}
|
|
|
|
// Triangle failed (before fix)
|
|
func (t *TriDense) Triangle() (nnnn int, kind bool) {
|
|
return 3, !t.IsZero() && t.triKind()
|
|
}
|
|
|
|
// Tryangle works -- difference is not-named output parameters.
|
|
func (t *TriDense) Tryangle() (int, bool) {
|
|
return 3, !t.IsZero() && t.triKind()
|
|
}
|
|
|
|
func main() {
|
|
ta := NewTriDense()
|
|
n, kind := ta.Triangle()
|
|
if kind == false {
|
|
println(" main n, kind=", n, ", ", kind, " (FAIL, expected true)")
|
|
}
|
|
ta.ScaleTri(1, ta)
|
|
ta.ScaleTry(1, ta)
|
|
}
|