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author | Chris Lattner <sabre@nondot.org> | 2007-12-11 06:07:39 +0000 |
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committer | Chris Lattner <sabre@nondot.org> | 2007-12-11 06:07:39 +0000 |
commit | 9eaa835e887a0a35161adf357af0e3d221e095d7 (patch) | |
tree | 9771c0b672e2ef2365c83db88851690060170f9f /lib/VMCore/ConstantFold.cpp | |
parent | 2b0f806c88f022094112ccc3aeb31c7d55f50874 (diff) | |
download | external_llvm-9eaa835e887a0a35161adf357af0e3d221e095d7.zip external_llvm-9eaa835e887a0a35161adf357af0e3d221e095d7.tar.gz external_llvm-9eaa835e887a0a35161adf357af0e3d221e095d7.tar.bz2 |
significantly simplify some code, no functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44850 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/VMCore/ConstantFold.cpp')
-rw-r--r-- | lib/VMCore/ConstantFold.cpp | 111 |
1 files changed, 23 insertions, 88 deletions
diff --git a/lib/VMCore/ConstantFold.cpp b/lib/VMCore/ConstantFold.cpp index 01b0100..6660c8d 100644 --- a/lib/VMCore/ConstantFold.cpp +++ b/lib/VMCore/ConstantFold.cpp @@ -36,81 +36,31 @@ using namespace llvm; // ConstantFold*Instruction Implementations //===----------------------------------------------------------------------===// -/// CastConstantVector - Convert the specified ConstantVector node to the +/// BitCastConstantVector - Convert the specified ConstantVector node to the /// specified vector type. At this point, we know that the elements of the /// input vector constant are all simple integer or FP values. -static Constant *CastConstantVector(ConstantVector *CV, - const VectorType *DstTy) { - unsigned SrcNumElts = CV->getType()->getNumElements(); - unsigned DstNumElts = DstTy->getNumElements(); - const Type *SrcEltTy = CV->getType()->getElementType(); - const Type *DstEltTy = DstTy->getElementType(); +static Constant *BitCastConstantVector(ConstantVector *CV, + const VectorType *DstTy) { + // If this cast changes element count then we can't handle it here: + // doing so requires endianness information. This should be handled by + // Analysis/ConstantFolding.cpp + unsigned NumElts = DstTy->getNumElements(); + if (NumElts != CV->getNumOperands()) + return 0; - // If both vectors have the same number of elements (thus, the elements - // are the same size), perform the conversion now. - if (SrcNumElts == DstNumElts) { - std::vector<Constant*> Result; - - // If the src and dest elements are both integers, or both floats, we can - // just BitCast each element because the elements are the same size. - if ((SrcEltTy->isInteger() && DstEltTy->isInteger()) || - (SrcEltTy->isFloatingPoint() && DstEltTy->isFloatingPoint())) { - for (unsigned i = 0; i != SrcNumElts; ++i) - Result.push_back( - ConstantExpr::getBitCast(CV->getOperand(i), DstEltTy)); - return ConstantVector::get(Result); - } - - // If this is an int-to-fp cast .. - if (SrcEltTy->isInteger()) { - // Ensure that it is int-to-fp cast - assert(DstEltTy->isFloatingPoint()); - if (DstEltTy->getTypeID() == Type::DoubleTyID) { - for (unsigned i = 0; i != SrcNumElts; ++i) { - ConstantInt *CI = cast<ConstantInt>(CV->getOperand(i)); - double V = CI->getValue().bitsToDouble(); - Result.push_back(ConstantFP::get(Type::DoubleTy, APFloat(V))); - } - return ConstantVector::get(Result); - } - assert(DstEltTy == Type::FloatTy && "Unknown fp type!"); - for (unsigned i = 0; i != SrcNumElts; ++i) { - ConstantInt *CI = cast<ConstantInt>(CV->getOperand(i)); - float V = CI->getValue().bitsToFloat(); - Result.push_back(ConstantFP::get(Type::FloatTy, APFloat(V))); - } - return ConstantVector::get(Result); - } - - // Otherwise, this is an fp-to-int cast. - assert(SrcEltTy->isFloatingPoint() && DstEltTy->isInteger()); - - if (SrcEltTy->getTypeID() == Type::DoubleTyID) { - for (unsigned i = 0; i != SrcNumElts; ++i) { - uint64_t V = cast<ConstantFP>(CV->getOperand(i))-> - getValueAPF().convertToAPInt().getZExtValue(); - Constant *C = ConstantInt::get(Type::Int64Ty, V); - Result.push_back(ConstantExpr::getBitCast(C, DstEltTy )); - } - return ConstantVector::get(Result); - } - - assert(SrcEltTy->getTypeID() == Type::FloatTyID); - for (unsigned i = 0; i != SrcNumElts; ++i) { - uint32_t V = (uint32_t)cast<ConstantFP>(CV->getOperand(i))-> - getValueAPF().convertToAPInt().getZExtValue(); - Constant *C = ConstantInt::get(Type::Int32Ty, V); - Result.push_back(ConstantExpr::getBitCast(C, DstEltTy)); - } - return ConstantVector::get(Result); + // Check to verify that all elements of the input are simple. + for (unsigned i = 0; i != NumElts; ++i) { + if (!isa<ConstantInt>(CV->getOperand(i)) && + !isa<ConstantFP>(CV->getOperand(i))) + return 0; } - - // Otherwise, this is a cast that changes element count and size. Handle - // casts which shrink the elements here. - - // FIXME: We need to know endianness to do this! - - return 0; + + // Bitcast each element now. + std::vector<Constant*> Result; + const Type *DstEltTy = DstTy->getElementType(); + for (unsigned i = 0; i != NumElts; ++i) + Result.push_back(ConstantExpr::getBitCast(CV->getOperand(i), DstEltTy)); + return ConstantVector::get(Result); } /// This function determines which opcode to use to fold two constant cast @@ -178,23 +128,8 @@ static Constant *FoldBitCast(Constant *V, const Type *DestTy) { if (isa<ConstantAggregateZero>(V)) return Constant::getNullValue(DestTy); - if (const ConstantVector *CV = dyn_cast<ConstantVector>(V)) { - // This is a cast from a ConstantVector of one type to a - // ConstantVector of another type. Check to see if all elements of - // the input are simple. - bool AllSimpleConstants = true; - for (unsigned i = 0, e = CV->getNumOperands(); i != e; ++i) { - if (!isa<ConstantInt>(CV->getOperand(i)) && - !isa<ConstantFP>(CV->getOperand(i))) { - AllSimpleConstants = false; - break; - } - } - - // If all of the elements are simple constants, we can fold this. - if (AllSimpleConstants) - return CastConstantVector(const_cast<ConstantVector*>(CV), DestPTy); - } + if (ConstantVector *CV = dyn_cast<ConstantVector>(V)) + return BitCastConstantVector(CV, DestPTy); } } |