Fix memory corruption. If one of the SCEV creation functions calls another but

doesn't return immediately after then the insert position in UniqueSCEVs will
be out of date. No test because this is a memory corruption issue. Fixes PR9051!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124282 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index c10af50dd597dd7ac958caf28e7adcf72dae3cd4..c2f3ac071de2c7e3a3c64000ba87ac19ae5c0536 100644 (file)
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -831,6 +831,7 @@ const SCEV *ScalarEvolution::getTruncateExpr(const SCEV *Op,
     }
     if (!hasTrunc)
       return getAddExpr(Operands, false, false);
+    UniqueSCEVs.FindNodeOrInsertPos(ID, IP);  // Mutates IP, returns NULL.
   }
 
   // trunc(x1*x2*...*xN) --> trunc(x1)*trunc(x2)*...*trunc(xN) if we can
@@ -845,6 +846,7 @@ const SCEV *ScalarEvolution::getTruncateExpr(const SCEV *Op,
     }
     if (!hasTrunc)
       return getMulExpr(Operands, false, false);
+    UniqueSCEVs.FindNodeOrInsertPos(ID, IP);  // Mutates IP, returns NULL.
   }
 
   // If the input value is a chrec scev, truncate the chrec's operands.