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c359d759a7
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
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// Copyright 2018 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package main
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const (
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Upper = true
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blas_Upper = 121
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badTriangle = "bad triangle"
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)
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// Triangular represents a triangular matrix. Triangular matrices are always square.
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type Triangular interface {
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// Triangular returns the number of rows/columns in the matrix and its
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// orientation.
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Tryangle() (mmmm int, kynd bool)
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Triangle() (mmmm int, kynd bool)
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}
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// blas64_Triangular represents a triangular matrix using the conventional storage scheme.
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type blas64_Triangular struct {
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Stride int
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Uplo int
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}
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// TriDense represents an upper or lower triangular matrix in dense storage
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// format.
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type TriDense struct {
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mat blas64_Triangular
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}
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func NewTriDense() *TriDense {
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return &TriDense{
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mat: blas64_Triangular{
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Stride: 3,
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Uplo: blas_Upper,
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},
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}
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}
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func (t *TriDense) isUpper() bool {
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return isUpperUplo(t.mat.Uplo)
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}
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func (t *TriDense) triKind() bool {
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return isUpperUplo(t.mat.Uplo)
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}
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func isUpperUplo(u int) bool {
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switch u {
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case blas_Upper:
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return true
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default:
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panic(badTriangle)
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}
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}
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func (t *TriDense) IsZero() bool {
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return t.mat.Stride == 0
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}
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//go:noinline
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func (t *TriDense) ScaleTri(f float64, a Triangular) {
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n, kind := a.Triangle()
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if kind == false {
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println("ScaleTri n, kind=", n, ", ", kind, " (FAIL, expected true)")
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}
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}
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//go:noinline
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func (t *TriDense) ScaleTry(f float64, a Triangular) {
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n, kind := a.Tryangle()
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if kind == false {
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println("ScaleTry n, kind=", n, ", ", kind, " (FAIL, expected true)")
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}
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}
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// Triangle failed (before fix)
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func (t *TriDense) Triangle() (nnnn int, kind bool) {
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return 3, !t.IsZero() && t.triKind()
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}
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// Tryangle works -- difference is not-named output parameters.
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func (t *TriDense) Tryangle() (int, bool) {
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return 3, !t.IsZero() && t.triKind()
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}
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func main() {
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ta := NewTriDense()
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n, kind := ta.Triangle()
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if kind == false {
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println(" main n, kind=", n, ", ", kind, " (FAIL, expected true)")
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}
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ta.ScaleTri(1, ta)
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ta.ScaleTry(1, ta)
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}
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