When transforming a call to a bitcast function into
a direct call with cast parameters and cast return
value (if any), instcombine was prepared to cast any
non-void return value into any other, whether castable
or not. Add a new predicate for testing whether casting
is valid, and check it both for the return value and
(as a cleanup) for the parameters.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45657 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index 1e12c79..4fcd47a 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -8082,11 +8082,7 @@
const FunctionType *FT = Callee->getFunctionType();
const Type *OldRetTy = Caller->getType();
- const ParamAttrsList* CallerPAL = 0;
- if (CallInst *CallerCI = dyn_cast<CallInst>(Caller))
- CallerPAL = CallerCI->getParamAttrs();
- else if (InvokeInst *CallerII = dyn_cast<InvokeInst>(Caller))
- CallerPAL = CallerII->getParamAttrs();
+ const ParamAttrsList* CallerPAL = CS.getParamAttrs();
// If the parameter attributes are not compatible, don't do the xform. We
// don't want to lose an sret attribute or something.
@@ -8101,6 +8097,12 @@
TD->getIntPtrType() == OldRetTy))
return false; // Cannot transform this return value.
+ if (!Caller->use_empty() &&
+ !CastInst::isCastable(FT->getReturnType(), OldRetTy) &&
+ // void -> non-void is handled specially
+ FT->getReturnType() != Type::VoidTy)
+ return false; // Cannot transform this return value.
+
// If the callsite is an invoke instruction, and the return value is used by
// a PHI node in a successor, we cannot change the return type of the call
// because there is no place to put the cast instruction (without breaking
@@ -8122,9 +8124,13 @@
for (unsigned i = 0, e = NumCommonArgs; i != e; ++i, ++AI) {
const Type *ParamTy = FT->getParamType(i);
const Type *ActTy = (*AI)->getType();
+
+ if (!CastInst::isCastable(ActTy, ParamTy))
+ return false;
+
ConstantInt *c = dyn_cast<ConstantInt>(*AI);
- //Some conversions are safe even if we do not have a body.
- //Either we can cast directly, or we can upconvert the argument
+ // Some conversions are safe even if we do not have a body.
+ // Either we can cast directly, or we can upconvert the argument
bool isConvertible = ActTy == ParamTy ||
(isa<PointerType>(ParamTy) && isa<PointerType>(ActTy)) ||
(ParamTy->isInteger() && ActTy->isInteger() &&
@@ -8132,40 +8138,6 @@
(c && ParamTy->getPrimitiveSizeInBits() >= ActTy->getPrimitiveSizeInBits()
&& c->getValue().isStrictlyPositive());
if (Callee->isDeclaration() && !isConvertible) return false;
-
- // Most other conversions can be done if we have a body, even if these
- // lose information, e.g. int->short.
- // Some conversions cannot be done at all, e.g. float to pointer.
- // Logic here parallels CastInst::getCastOpcode (the design there
- // requires legality checks like this be done before calling it).
- if (ParamTy->isInteger()) {
- if (const VectorType *VActTy = dyn_cast<VectorType>(ActTy)) {
- if (VActTy->getBitWidth() != ParamTy->getPrimitiveSizeInBits())
- return false;
- }
- if (!ActTy->isInteger() && !ActTy->isFloatingPoint() &&
- !isa<PointerType>(ActTy))
- return false;
- } else if (ParamTy->isFloatingPoint()) {
- if (const VectorType *VActTy = dyn_cast<VectorType>(ActTy)) {
- if (VActTy->getBitWidth() != ParamTy->getPrimitiveSizeInBits())
- return false;
- }
- if (!ActTy->isInteger() && !ActTy->isFloatingPoint())
- return false;
- } else if (const VectorType *VParamTy = dyn_cast<VectorType>(ParamTy)) {
- if (const VectorType *VActTy = dyn_cast<VectorType>(ActTy)) {
- if (VActTy->getBitWidth() != VParamTy->getBitWidth())
- return false;
- }
- if (VParamTy->getBitWidth() != ActTy->getPrimitiveSizeInBits())
- return false;
- } else if (isa<PointerType>(ParamTy)) {
- if (!ActTy->isInteger() && !isa<PointerType>(ActTy))
- return false;
- } else {
- return false;
- }
}
if (FT->getNumParams() < NumActualArgs && !FT->isVarArg() &&
@@ -8238,12 +8210,11 @@
// Insert a cast of the return type as necessary.
Value *NV = NC;
- if (Caller->getType() != NV->getType() && !Caller->use_empty()) {
+ if (OldRetTy != NV->getType() && !Caller->use_empty()) {
if (NV->getType() != Type::VoidTy) {
- const Type *CallerTy = Caller->getType();
Instruction::CastOps opcode = CastInst::getCastOpcode(NC, false,
- CallerTy, false);
- NV = NC = CastInst::create(opcode, NC, CallerTy, "tmp");
+ OldRetTy, false);
+ NV = NC = CastInst::create(opcode, NC, OldRetTy, "tmp");
// If this is an invoke instruction, we should insert it after the first
// non-phi, instruction in the normal successor block.