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| author | Duncan Sands <baldrick@free.fr> | 2012-05-22 14:17:53 +0000 |
|---|---|---|
| committer | Duncan Sands <baldrick@free.fr> | 2012-05-22 14:17:53 +0000 |
| commit | 5cdbb1de7d9ca578330b35b7fb7b10296216316b (patch) | |
| tree | 46567e7a91d9af1f6634437743f3ba9b8425fb98 /test | |
| parent | 85b9e56bac85b30ede70e46ef9f60e4dec3b88f3 (diff) | |
| download | llvm-5cdbb1de7d9ca578330b35b7fb7b10296216316b.tar.gz llvm-5cdbb1de7d9ca578330b35b7fb7b10296216316b.tar.bz2 llvm-5cdbb1de7d9ca578330b35b7fb7b10296216316b.tar.xz | |
Fix PR12858, a crash due to GVN's PRE not fully removing an instruction from the
leader table. That's because it wasn't expecting instructions to turn up as
leader for a value number that is not its own, but equality propagation could
create this situation. One solution is to have the leader table use a WeakVH
but this slows down GVN by about 5%. Instead just have equality propagation not
add instructions to the leader table, only constants and arguments. In theory
this might cause GVN to run more (each time it changes something it runs again)
but it doesn't seem to occur enough to cause a slow down.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157251 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test')
| -rw-r--r-- | test/Transforms/GVN/2012-05-22-PreCrash.ll | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/test/Transforms/GVN/2012-05-22-PreCrash.ll b/test/Transforms/GVN/2012-05-22-PreCrash.ll new file mode 100644 index 0000000000..b488dda9c3 --- /dev/null +++ b/test/Transforms/GVN/2012-05-22-PreCrash.ll @@ -0,0 +1,33 @@ +; RUN: opt < %s -gvn +; PR12858 + +define void @fn5(i16 signext %p1, i8 signext %p2) nounwind uwtable { +entry: + br i1 undef, label %if.else, label %if.then + +if.then: ; preds = %entry + br label %if.end + +if.else: ; preds = %entry + %conv = sext i16 %p1 to i32 + br label %if.end + +if.end: ; preds = %if.else, %if.then + %conv1 = sext i16 %p1 to i32 + br i1 undef, label %if.then3, label %if.else4 + +if.then3: ; preds = %if.end + br label %if.end12 + +if.else4: ; preds = %if.end + %conv7 = sext i8 %p2 to i32 + %cmp8 = icmp eq i32 %conv1, %conv7 + br i1 %cmp8, label %if.then10, label %if.end12 + +if.then10: ; preds = %if.else4 + br label %if.end12 + +if.end12: ; preds = %if.then10, %if.else4, %if.then3 + %conv13 = sext i8 %p2 to i32 + ret void +} |