[PATCH] D43544: [Transforms][SROA] Fixed assertion crash (PR30416)

[Konstantin Belochapka via Phabricator via llvm-commits]

kbelochapka created this revision.
kbelochapka added reviewers: luqmana, rafael.

Problem:
In certain situations during ALLOCA promotion, the promoteSingleBlockAlloca() function attempts to replace an instruction by itself. This causes the assertion crash described in PR30416.

Solution:
Disable SROA for a Basic Block that can cause circular dependency.


https://reviews.llvm.org/D43544

Files:
  lib/Transforms/Utils/PromoteMemoryToRegister.cpp


Index: lib/Transforms/Utils/PromoteMemoryToRegister.cpp
===================================================================
--- lib/Transforms/Utils/PromoteMemoryToRegister.cpp
+++ lib/Transforms/Utils/PromoteMemoryToRegister.cpp
@@ -509,6 +509,9 @@
           !isKnownNonZero(ReplVal, DL, 0, AC, LI, &DT))
         addAssumeNonNull(AC, LI);
 
+      // we have a loop, bail out
+      if (LI == ReplVal)
+        return false;
       LI->replaceAllUsesWith(ReplVal);
     }
 


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D43544.135188.patch
Type: text/x-patch
Size: 477 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20180221/d457ad84/attachment.bin>