mirror of
https://github.com/golang/go
synced 2024-10-14 20:05:36 +00:00
cmd/compile: reset branch prediction when deleting a branch
When we go from a branch block to a plain block, reset the branch prediction bit. Downstream passes asssume that if the branch prediction is set, then the block has 2 successors. Fixes #23504 Change-Id: I2898ec002228b2e34fe80ce420c6939201c0a5aa Reviewed-on: https://go-review.googlesource.com/88955 Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
This commit is contained in:
parent
252ee90971
commit
4313d7767d
|
@ -102,7 +102,7 @@ func checkFunc(f *Func) {
|
||||||
f.Fatalf("plain/dead block %s has a control value", b)
|
f.Fatalf("plain/dead block %s has a control value", b)
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
if len(b.Succs) > 2 && b.Likely != BranchUnknown {
|
if len(b.Succs) != 2 && b.Likely != BranchUnknown {
|
||||||
f.Fatalf("likeliness prediction %d for block %s with %d successors", b.Likely, b, len(b.Succs))
|
f.Fatalf("likeliness prediction %d for block %s with %d successors", b.Likely, b, len(b.Succs))
|
||||||
}
|
}
|
||||||
|
|
||||||
|
|
|
@ -92,6 +92,7 @@ func fuseBlockIf(b *Block) bool {
|
||||||
b.removeEdge(1)
|
b.removeEdge(1)
|
||||||
}
|
}
|
||||||
b.Kind = BlockPlain
|
b.Kind = BlockPlain
|
||||||
|
b.Likely = BranchUnknown
|
||||||
b.SetControl(nil)
|
b.SetControl(nil)
|
||||||
|
|
||||||
// Trash the empty blocks s0 & s1.
|
// Trash the empty blocks s0 & s1.
|
||||||
|
|
15
test/fixedbugs/issue23504.go
Normal file
15
test/fixedbugs/issue23504.go
Normal file
|
@ -0,0 +1,15 @@
|
||||||
|
// compile
|
||||||
|
|
||||||
|
// 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 p
|
||||||
|
|
||||||
|
func f() {
|
||||||
|
var B bool
|
||||||
|
B2 := (B || B && !B) && !B
|
||||||
|
B3 := B2 || B
|
||||||
|
for (B3 || B2) && !B2 && B {
|
||||||
|
}
|
||||||
|
}
|
Loading…
Reference in a new issue