Fix surprising missed optimization in mergefunc where we forgot to consider
that relationships like "i8* null" is equivalent to "i32* null".
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124368 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/IPO/MergeFunctions.cpp b/lib/Transforms/IPO/MergeFunctions.cpp
index 1e328ca..fb55d7c 100644
--- a/lib/Transforms/IPO/MergeFunctions.cpp
+++ b/lib/Transforms/IPO/MergeFunctions.cpp
@@ -460,9 +460,18 @@
if (V1 == F2 && V2 == F1)
return true;
- // TODO: constant expressions with GEP or references to F1 or F2.
- if (isa<Constant>(V1))
- return V1 == V2;
+ if (isa<Constant>(V1)) {
+ if (V1 == V2) return true;
+ const Constant *C1 = cast<Constant>(V1);
+ const Constant *C2 = dyn_cast<Constant>(V2);
+ if (!C2) return false;
+ // TODO: constant expressions with GEP or references to F1 or F2.
+ if (C1->isNullValue() && C2->isNullValue() &&
+ isEquivalentType(C1->getType(), C2->getType()))
+ return true;
+ return C1->getType()->canLosslesslyBitCastTo(C2->getType()) &&
+ C1 == ConstantExpr::getBitCast(const_cast<Constant*>(C2), C1->getType());
+ }
if (isa<InlineAsm>(V1) && isa<InlineAsm>(V2)) {
const InlineAsm *IA1 = cast<InlineAsm>(V1);