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| author | Mikael Holmen <mikael.holmen@ericsson.com> | 2020-04-08 11:58:26 +0200 |
|---|---|---|
| committer | Mikael Holmen <mikael.holmen@ericsson.com> | 2020-04-08 12:50:36 +0200 |
| commit | 893df2032d480bf791a69fe965c3ca4ef500145b (patch) | |
| tree | a7dd655b09ca6bf597e265df1906f8af457af265 /llvm/lib/CodeGen/IfConversion.cpp | |
| parent | 89e1248d7b76886912f499391719e68b27e42ec3 (diff) | |
| download | llvm-893df2032d480bf791a69fe965c3ca4ef500145b.zip llvm-893df2032d480bf791a69fe965c3ca4ef500145b.tar.gz llvm-893df2032d480bf791a69fe965c3ca4ef500145b.tar.bz2 | |
[IfConversion] Disallow TrueBB == FalseBB for valid diamonds
Summary:
This fixes PR45302.
Previously the case
BB1
/ \
| |
TBB FBB
| |
\ /
BB2
was treated as a valid diamond also when TBB and FBB was the same basic
block. This then lead to a failed assertion in IfConvertDiamond.
Since TBB == FBB is quite a degenerated case of a diamond, we now
don't treat it as a valid diamond anymore, and thus we will avoid the
trouble of making IfConvertDiamond handle it correctly.
Reviewers: efriedma, kparzysz
Reviewed By: efriedma
Subscribers: hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D77651
Diffstat (limited to 'llvm/lib/CodeGen/IfConversion.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/IfConversion.cpp | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/IfConversion.cpp b/llvm/lib/CodeGen/IfConversion.cpp index 77fa128..90c471c 100644 --- a/llvm/lib/CodeGen/IfConversion.cpp +++ b/llvm/lib/CodeGen/IfConversion.cpp @@ -972,6 +972,11 @@ bool IfConverter::ValidDiamond( FalseBBI.IsBeingAnalyzed || FalseBBI.IsDone) return false; + // If the True and False BBs are equal we're dealing with a degenerate case + // that we don't treat as a diamond. + if (TrueBBI.BB == FalseBBI.BB) + return false; + MachineBasicBlock *TT = TrueBBI.TrueBB; MachineBasicBlock *FT = FalseBBI.TrueBB; |