[ConstFold] Don't fold calls with mismatching function type

With opaque pointers, this is no longer ensured through pointer
type identity.

diff --git a/llvm/lib/Analysis/ConstantFolding.cpp b/llvm/lib/Analysis/ConstantFolding.cpp
index fd82bac..359d5bb 100644 (file)
--- a/llvm/lib/Analysis/ConstantFolding.cpp
+++ b/llvm/lib/Analysis/ConstantFolding.cpp
@@ -1388,6 +1388,8 @@ Constant *llvm::ConstantFoldCastOperand(unsigned Opcode, Constant *C,
 bool llvm::canConstantFoldCallTo(const CallBase *Call, const Function *F) {
   if (Call->isNoBuiltin())
     return false;
+  if (Call->getFunctionType() != F->getFunctionType())
+    return false;
   switch (F->getIntrinsicID()) {
   // Operations that do not operate floating-point numbers and do not depend on
   // FP environment can be folded even in strictfp functions.

diff --git a/llvm/test/Transforms/InstCombine/opaque-ptr.ll b/llvm/test/Transforms/InstCombine/opaque-ptr.ll
index 56ee71e..dd347a9 100644 (file)
--- a/llvm/test/Transforms/InstCombine/opaque-ptr.ll
+++ b/llvm/test/Transforms/InstCombine/opaque-ptr.ll
@@ -516,3 +516,14 @@ define void @call_cast_byval(ptr %p, ptr %p2) {
   call void @call_byval(ptr %p, ptr byval(double) %p2)
   ret void
 }
+
+declare float @fmodf(float, float)
+
+define i32 @const_fold_call_with_func_type_mismatch() {
+; CHECK-LABEL: @const_fold_call_with_func_type_mismatch(
+; CHECK-NEXT:    [[V:%.*]] = call float @fmodf(float 0x40091EB860000000, float 2.000000e+00)
+; CHECK-NEXT:    ret i32 1066527622
+;
+  %v = call i32 @fmodf(float 0x40091EB860000000, float 2.000000e+00)
+  ret i32 %v
+}