It is possible, under specific circumstances involving ptrtoint ConstantExpr's, for LVI to end up trying to merge

a Constant into a ConstantRange.  Handle this conservatively for now, rather than asserting.  The testcase is
more complex that I would like, but the manifestation of the problem is sensitive to iteration orders and the state of the
LVI cache, and I have not been able to reproduce it with manually constructed or simplified cases.

Fixes PR8162.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114103 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 7 insertions, 3 deletions

diff --git a/lib/Analysis/LazyValueInfo.cpp b/lib/Analysis/LazyValueInfo.cpp
index 74267e045a..0e024042f1 100644
--- a/lib/Analysis/LazyValueInfo.cpp
+++ b/lib/Analysis/LazyValueInfo.cpp
@@ -201,6 +201,7 @@ public:
           return markOverdefined();
         return markNotConstant(RHS.getNotConstant());
       } else if (isConstantRange()) {
+         // FIXME: This could be made more precise.
         return markOverdefined();
       }
       
@@ -223,9 +224,12 @@ public:
       return markConstantRange(RHS.getConstantRange());
     }
     
-    // RHS must be a constant, we must be undef, constant, or notconstant.
-    assert(!isConstantRange() &&
-           "Constant and ConstantRange cannot be merged.");
+    // RHS must be a constant, we must be constantrange, 
+    // undef, constant, or notconstant.
+    if (isConstantRange()) {
+      // FIXME: This could be made more precise.
+      return markOverdefined();
+    }
     
     if (isUndefined())
       return markConstant(RHS.getConstant());