[PATCH] D115781: Try to do somethink with misscompile bug in widenable condition.

[Dmitry Bakunevich via Phabricator via llvm-commits]

dbakunevich created this revision.
dbakunevich added a reviewer: mkazantsev.
Herald added a subscriber: hiraditya.
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When working with optimizations on widenable condition, a misscompile bug was found. 
@mkazantsev tried to fix it, but was never approved. 
Yesterday I ran into this bug again. Therefore, I decided that in the case of an infinite loop, do not fall by assert, but break out of the loop.
Link to Maxim's patch https://reviews.llvm.org/D112693


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D115781

Files:
  llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp


Index: llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp
+++ llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp
@@ -227,7 +227,9 @@
   unsigned IterCnt = 0;
   (void)IterCnt;
   while (LocalChange) {
-    assert(IterCnt++ < 1000 && "Iterative simplification didn't converge!");
+    if (IterCnt++ < 1000)
+      break;
+    // TODO: Fix infinite loop bug when working with widenable condition.
     LocalChange = false;
 
     // Loop over all of the basic blocks and remove them if they are unneeded.


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