Make getModRefInfo(Instruction *) not crash on certain types of instructions
llvm-svn: 236023
diff --git a/llvm/lib/Analysis/AliasAnalysis.cpp b/llvm/lib/Analysis/AliasAnalysis.cpp
index 43db176..1ee60ff 100644
--- a/llvm/lib/Analysis/AliasAnalysis.cpp
+++ b/llvm/lib/Analysis/AliasAnalysis.cpp
@@ -379,15 +379,18 @@
AliasAnalysis::ModRefResult
AliasAnalysis::getModRefInfo(const VAArgInst *V, const Location &Loc) {
- // If the va_arg address cannot alias the pointer in question, then the
- // specified memory cannot be accessed by the va_arg.
- if (!alias(getLocation(V), Loc))
- return NoModRef;
- // If the pointer is a pointer to constant memory, then it could not have been
- // modified by this va_arg.
- if (pointsToConstantMemory(Loc))
- return NoModRef;
+ if (Loc.Ptr) {
+ // If the va_arg address cannot alias the pointer in question, then the
+ // specified memory cannot be accessed by the va_arg.
+ if (!alias(getLocation(V), Loc))
+ return NoModRef;
+
+ // If the pointer is a pointer to constant memory, then it could not have
+ // been modified by this va_arg.
+ if (pointsToConstantMemory(Loc))
+ return NoModRef;
+ }
// Otherwise, a va_arg reads and writes.
return ModRef;
@@ -400,7 +403,7 @@
return ModRef;
// If the cmpxchg address does not alias the location, it does not access it.
- if (!alias(getLocation(CX), Loc))
+ if (Loc.Ptr && !alias(getLocation(CX), Loc))
return NoModRef;
return ModRef;
@@ -413,7 +416,7 @@
return ModRef;
// If the atomicrmw address does not alias the location, it does not access it.
- if (!alias(getLocation(RMW), Loc))
+ if (Loc.Ptr && !alias(getLocation(RMW), Loc))
return NoModRef;
return ModRef;