Author: baldrick
Date: Sun Jan 6 04:12:28 2008
New Revision: 45657
URL: http://llvm.org/viewvc/llvm-project?rev=45657&view=rev
Log:
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.
Added:
llvm/trunk/test/Transforms/InstCombine/2008-01-06-CastCrash.ll
llvm/trunk/test/Transforms/InstCombine/2008-01-06-VoidCast.ll
Modified:
llvm/trunk/include/llvm/InstrTypes.h
llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp
llvm/trunk/lib/VMCore/Instructions.cpp
Modified: llvm/trunk/include/llvm/InstrTypes.h
URL:
http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/InstrTypes.h?rev=45657&r1=45656&r2=45657&view=diff
==============================================================================
--- llvm/trunk/include/llvm/InstrTypes.h (original)
+++ llvm/trunk/include/llvm/InstrTypes.h Sun Jan 6 04:12:28 2008
@@ -398,8 +398,14 @@
BasicBlock *InsertAtEnd ///< The block to insert the instruction into
);
+ /// @brief Check whether it is valid to call getCastOpcode for these types.
+ static bool isCastable(
+ const Type *SrcTy, ///< The Type from which the value should be cast.
+ const Type *DestTy ///< The Type to which the value should be cast.
+ );
+
/// Returns the opcode necessary to cast Val into Ty using usual casting
- /// rules.
+ /// rules.
/// @brief Infer the opcode for cast operand and type
static Instruction::CastOps getCastOpcode(
const Value *Val, ///< The value to cast
Modified: llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp
URL:
http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp?rev=45657&r1=45656&r2=45657&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp Sun Jan 6
04:12:28 2008
@@ -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.
Modified: llvm/trunk/lib/VMCore/Instructions.cpp
URL:
http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/VMCore/Instructions.cpp?rev=45657&r1=45656&r2=45657&view=diff
==============================================================================
--- llvm/trunk/lib/VMCore/Instructions.cpp (original)
+++ llvm/trunk/lib/VMCore/Instructions.cpp Sun Jan 6 04:12:28 2008
@@ -1895,12 +1895,70 @@
return create(opcode, C, Ty, Name, InsertAtEnd);
}
+// Check whether it is valid to call getCastOpcode for these types.
+// This routine must be kept in sync with getCastOpcode.
+bool CastInst::isCastable(const Type *SrcTy, const Type *DestTy) {
+ if (!SrcTy->isFirstClassType() || !DestTy->isFirstClassType())
+ return false;
+
+ if (SrcTy == DestTy)
+ return true;
+
+ // Get the bit sizes, we'll need these
+ unsigned SrcBits = SrcTy->getPrimitiveSizeInBits(); // 0 for ptr/vector
+ unsigned DestBits = DestTy->getPrimitiveSizeInBits(); // 0 for ptr/vector
+
+ // Run through the possibilities ...
+ if (DestTy->isInteger()) { // Casting to integral
+ if (SrcTy->isInteger()) { // Casting from integral
+ return true;
+ } else if (SrcTy->isFloatingPoint()) { // Casting from floating pt
+ return true;
+ } else if (const VectorType *PTy = dyn_cast<VectorType>(SrcTy)) {
+ // Casting from vector
+ return DestBits == PTy->getBitWidth();
+ } else { // Casting from something
else
+ return isa<PointerType>(SrcTy);
+ }
+ } else if (DestTy->isFloatingPoint()) { // Casting to floating pt
+ if (SrcTy->isInteger()) { // Casting from integral
+ return true;
+ } else if (SrcTy->isFloatingPoint()) { // Casting from floating pt
+ return true;
+ } else if (const VectorType *PTy = dyn_cast<VectorType>(SrcTy)) {
+ // Casting from vector
+ return DestBits == PTy->getBitWidth();
+ } else { // Casting from something
else
+ return false;
+ }
+ } else if (const VectorType *DestPTy = dyn_cast<VectorType>(DestTy)) {
+ // Casting to vector
+ if (const VectorType *SrcPTy = dyn_cast<VectorType>(SrcTy)) {
+ // Casting from vector
+ return DestPTy->getBitWidth() == SrcPTy->getBitWidth();
+ } else { // Casting from something
else
+ return DestPTy->getBitWidth() == SrcBits;
+ }
+ } else if (isa<PointerType>(DestTy)) { // Casting to pointer
+ if (isa<PointerType>(SrcTy)) { // Casting from pointer
+ return true;
+ } else if (SrcTy->isInteger()) { // Casting from integral
+ return true;
+ } else { // Casting from something
else
+ return false;
+ }
+ } else { // Casting to something else
+ return false;
+ }
+}
+
// Provide a way to get a "cast" where the cast opcode is inferred from the
// types and size of the operand. This, basically, is a parallel of the
// logic in the castIsValid function below. This axiom should hold:
// castIsValid( getCastOpcode(Val, Ty), Val, Ty)
// should not assert in castIsValid. In other words, this produces a "correct"
// casting opcode for the arguments passed to it.
+// This routine must be kept in sync with isCastable.
Instruction::CastOps
CastInst::getCastOpcode(
const Value *Src, bool SrcIsSigned, const Type *DestTy, bool DestIsSigned) {
@@ -1909,6 +1967,9 @@
unsigned SrcBits = SrcTy->getPrimitiveSizeInBits(); // 0 for ptr/vector
unsigned DestBits = DestTy->getPrimitiveSizeInBits(); // 0 for ptr/vector
+ assert(SrcTy->isFirstClassType() && DestTy->isFirstClassType() &&
+ "Only first class types are castable!");
+
// Run through the possibilities ...
if (DestTy->isInteger()) { // Casting to integral
if (SrcTy->isInteger()) { // Casting from integral
@@ -2050,7 +2111,7 @@
if (isa<PointerType>(SrcTy) != isa<PointerType>(DstTy))
return false;
- // Now we know we're not dealing with a pointer/non-poiner mismatch. In all
+ // Now we know we're not dealing with a pointer/non-pointer mismatch. In
all
// these cases, the cast is okay if the source and destination bit widths
// are identical.
return SrcBitSize == DstBitSize;
Added: llvm/trunk/test/Transforms/InstCombine/2008-01-06-CastCrash.ll
URL:
http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/2008-01-06-CastCrash.ll?rev=45657&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/2008-01-06-CastCrash.ll (added)
+++ llvm/trunk/test/Transforms/InstCombine/2008-01-06-CastCrash.ll Sun Jan 6
04:12:28 2008
@@ -0,0 +1,10 @@
+; RUN: llvm-as < %s | opt -instcombine -disable-output
+
+define <2 x i32> @f() {
+ ret <2 x i32> undef
+}
+
+define i32 @g() {
+ %x = call i32 bitcast (<2 x i32> ()* @f to i32 ()*)( ) ; <i32>
[#uses=1]
+ ret i32 %x
+}
Added: llvm/trunk/test/Transforms/InstCombine/2008-01-06-VoidCast.ll
URL:
http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/2008-01-06-VoidCast.ll?rev=45657&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/2008-01-06-VoidCast.ll (added)
+++ llvm/trunk/test/Transforms/InstCombine/2008-01-06-VoidCast.ll Sun Jan 6
04:12:28 2008
@@ -0,0 +1,10 @@
+; RUN: llvm-as < %s | opt -instcombine | llvm-dis | not grep bitcast
+
+define void @f(i16 %y) {
+ ret void
+}
+
+define i32 @g(i32 %y) {
+ %x = call i32 bitcast (void (i16)* @f to i32 (i32)*)( i32 %y )
; <i32> [#uses=1]
+ ret i32 %x
+}
_______________________________________________
llvm-commits mailing list
llvm-commits@cs.uiuc.edu
http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
