Revert "Disable InstCombine unsafe folding bitcasts of calls w/ varargs."
This reverts commit d0e277d272d517ca1cda368267d199f0da7cad95.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149647 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/InstCombine/InstCombineCalls.cpp b/lib/Transforms/InstCombine/InstCombineCalls.cpp
index c3c13ae..a87fbbd 100644
--- a/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -1105,12 +1105,21 @@
if (FT->isVarArg()!=cast<FunctionType>(APTy->getElementType())->isVarArg())
return false;
}
+
+ if (FT->getNumParams() < NumActualArgs && FT->isVarArg() &&
+ !CallerPAL.isEmpty())
+ // In this case we have more arguments than the new function type, but we
+ // won't be dropping them. Check that these extra arguments have attributes
+ // that are compatible with being a vararg call argument.
+ for (unsigned i = CallerPAL.getNumSlots(); i; --i) {
+ if (CallerPAL.getSlot(i - 1).Index <= FT->getNumParams())
+ break;
+ Attributes PAttrs = CallerPAL.getSlot(i - 1).Attrs;
+ if (PAttrs & Attribute::VarArgsIncompatible)
+ return false;
+ }
- // If we're casting varargs to non-varargs, that may not be allowable
- // under the ABI, so conservatively don't do anything.
- if (FT->getNumParams() < NumActualArgs && FT->isVarArg())
- return false;
-
+
// Okay, we decided that this is a safe thing to do: go ahead and start
// inserting cast instructions as necessary.
std::vector<Value*> Args;