From 9eaa835e887a0a35161adf357af0e3d221e095d7 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Tue, 11 Dec 2007 06:07:39 +0000 Subject: [PATCH] significantly simplify some code, no functionality change. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44850 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/VMCore/ConstantFold.cpp | 111 ++++++++---------------------------- 1 file changed, 23 insertions(+), 88 deletions(-) diff --git a/lib/VMCore/ConstantFold.cpp b/lib/VMCore/ConstantFold.cpp index 01b0100c518..6660c8d3e2f 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 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(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(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(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(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(CV->getOperand(i)) && + !isa(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 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(V)) return Constant::getNullValue(DestTy); - if (const ConstantVector *CV = dyn_cast(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(CV->getOperand(i)) && - !isa(CV->getOperand(i))) { - AllSimpleConstants = false; - break; - } - } - - // If all of the elements are simple constants, we can fold this. - if (AllSimpleConstants) - return CastConstantVector(const_cast(CV), DestPTy); - } + if (ConstantVector *CV = dyn_cast(V)) + return BitCastConstantVector(CV, DestPTy); } }