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Diffstat (limited to 'lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp')
| -rw-r--r-- | lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp | 452 |
1 files changed, 452 insertions, 0 deletions
diff --git a/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp b/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp new file mode 100644 index 0000000000..d4e5a45876 --- /dev/null +++ b/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp @@ -0,0 +1,452 @@ +//===-------- LegalizeFloatTypes.cpp - Legalization of float types --------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file implements float type expansion and conversion of float types to +// integer types on behalf of LegalizeTypes. +// Converting to integer is the act of turning a computation in an illegal +// floating point type into a computation in an integer type of the same size. +// For example, turning f32 arithmetic into operations using i32. Also known as +// "soft float". The result is equivalent to bitcasting the float value to the +// integer type. +// Expansion is the act of changing a computation in an illegal type to be a +// computation in multiple registers of a smaller type. For example, +// implementing ppcf128 arithmetic in two f64 registers. +// +//===----------------------------------------------------------------------===// + +#include "LegalizeTypes.h" +#include "llvm/CodeGen/PseudoSourceValue.h" +#include "llvm/Constants.h" +#include "llvm/DerivedTypes.h" +using namespace llvm; + +/// GetFPLibCall - Return the right libcall for the given floating point type. +static RTLIB::Libcall GetFPLibCall(MVT VT, + RTLIB::Libcall Call_F32, + RTLIB::Libcall Call_F64, + RTLIB::Libcall Call_F80, + RTLIB::Libcall Call_PPCF128) { + return + VT == MVT::f32 ? Call_F32 : + VT == MVT::f64 ? Call_F64 : + VT == MVT::f80 ? Call_F80 : + VT == MVT::ppcf128 ? Call_PPCF128 : + RTLIB::UNKNOWN_LIBCALL; +} + +//===----------------------------------------------------------------------===// +// Result Float to Integer Conversion. +//===----------------------------------------------------------------------===// + +void DAGTypeLegalizer::PromoteFloatResult(SDNode *N, unsigned ResNo) { + DEBUG(cerr << "Promote float result " << ResNo << ": "; N->dump(&DAG); + cerr << "\n"); + SDOperand R = SDOperand(); + + // FIXME: Custom lowering for float-to-int? +#if 0 + // See if the target wants to custom convert this node to an integer. + if (TLI.getOperationAction(N->getOpcode(), N->getValueType(0)) == + TargetLowering::Custom) { + // If the target wants to, allow it to lower this itself. + if (SDNode *P = TLI.FloatToIntOperationResult(N, DAG)) { + // Everything that once used N now uses P. We are guaranteed that the + // result value types of N and the result value types of P match. + ReplaceNodeWith(N, P); + return; + } + } +#endif + + switch (N->getOpcode()) { + default: +#ifndef NDEBUG + cerr << "PromoteFloatResult #" << ResNo << ": "; + N->dump(&DAG); cerr << "\n"; +#endif + assert(0 && "Do not know how to convert the result of this operator!"); + abort(); + + case ISD::BIT_CONVERT: R = PromoteFloatRes_BIT_CONVERT(N); break; + case ISD::BUILD_PAIR: R = PromoteFloatRes_BUILD_PAIR(N); break; + case ISD::ConstantFP: + R = PromoteFloatRes_ConstantFP(cast<ConstantFPSDNode>(N)); + break; + case ISD::FCOPYSIGN: R = PromoteFloatRes_FCOPYSIGN(N); break; + case ISD::LOAD: R = PromoteFloatRes_LOAD(N); break; + case ISD::SINT_TO_FP: + case ISD::UINT_TO_FP: R = PromoteFloatRes_XINT_TO_FP(N); break; + + case ISD::FADD: R = PromoteFloatRes_FADD(N); break; + case ISD::FMUL: R = PromoteFloatRes_FMUL(N); break; + case ISD::FSUB: R = PromoteFloatRes_FSUB(N); break; + } + + // If R is null, the sub-method took care of registering the result. + if (R.Val) + SetPromotedFloat(SDOperand(N, ResNo), R); +} + +SDOperand DAGTypeLegalizer::PromoteFloatRes_BIT_CONVERT(SDNode *N) { + return BitConvertToInteger(N->getOperand(0)); +} + +SDOperand DAGTypeLegalizer::PromoteFloatRes_BUILD_PAIR(SDNode *N) { + // Convert the inputs to integers, and build a new pair out of them. + return DAG.getNode(ISD::BUILD_PAIR, + TLI.getTypeToTransformTo(N->getValueType(0)), + BitConvertToInteger(N->getOperand(0)), + BitConvertToInteger(N->getOperand(1))); +} + +SDOperand DAGTypeLegalizer::PromoteFloatRes_ConstantFP(ConstantFPSDNode *N) { + return DAG.getConstant(N->getValueAPF().convertToAPInt(), + TLI.getTypeToTransformTo(N->getValueType(0))); +} + +SDOperand DAGTypeLegalizer::PromoteFloatRes_FADD(SDNode *N) { + MVT NVT = TLI.getTypeToTransformTo(N->getValueType(0)); + SDOperand Ops[2] = { GetPromotedFloat(N->getOperand(0)), + GetPromotedFloat(N->getOperand(1)) }; + return MakeLibCall(GetFPLibCall(N->getValueType(0), + RTLIB::ADD_F32, + RTLIB::ADD_F64, + RTLIB::ADD_F80, + RTLIB::ADD_PPCF128), + NVT, Ops, 2, false/*sign irrelevant*/); +} + +SDOperand DAGTypeLegalizer::PromoteFloatRes_FCOPYSIGN(SDNode *N) { + SDOperand LHS = GetPromotedFloat(N->getOperand(0)); + SDOperand RHS = BitConvertToInteger(N->getOperand(1)); + + MVT LVT = LHS.getValueType(); + MVT RVT = RHS.getValueType(); + + unsigned LSize = LVT.getSizeInBits(); + unsigned RSize = RVT.getSizeInBits(); + + // First get the sign bit of second operand. + SDOperand SignBit = DAG.getNode(ISD::SHL, RVT, DAG.getConstant(1, RVT), + DAG.getConstant(RSize - 1, + TLI.getShiftAmountTy())); + SignBit = DAG.getNode(ISD::AND, RVT, RHS, SignBit); + + // Shift right or sign-extend it if the two operands have different types. + int SizeDiff = RVT.getSizeInBits() - LVT.getSizeInBits(); + if (SizeDiff > 0) { + SignBit = DAG.getNode(ISD::SRL, RVT, SignBit, + DAG.getConstant(SizeDiff, TLI.getShiftAmountTy())); + SignBit = DAG.getNode(ISD::TRUNCATE, LVT, SignBit); + } else if (SizeDiff < 0) { + SignBit = DAG.getNode(ISD::ANY_EXTEND, LVT, SignBit); + SignBit = DAG.getNode(ISD::SHL, LVT, SignBit, + DAG.getConstant(-SizeDiff, TLI.getShiftAmountTy())); + } + + // Clear the sign bit of the first operand. + SDOperand Mask = DAG.getNode(ISD::SHL, LVT, DAG.getConstant(1, LVT), + DAG.getConstant(LSize - 1, + TLI.getShiftAmountTy())); + Mask = DAG.getNode(ISD::SUB, LVT, Mask, DAG.getConstant(1, LVT)); + LHS = DAG.getNode(ISD::AND, LVT, LHS, Mask); + + // Or the value with the sign bit. + return DAG.getNode(ISD::OR, LVT, LHS, SignBit); +} + +SDOperand DAGTypeLegalizer::PromoteFloatRes_FMUL(SDNode *N) { + MVT NVT = TLI.getTypeToTransformTo(N->getValueType(0)); + SDOperand Ops[2] = { GetPromotedFloat(N->getOperand(0)), + GetPromotedFloat(N->getOperand(1)) }; + return MakeLibCall(GetFPLibCall(N->getValueType(0), + RTLIB::MUL_F32, + RTLIB::MUL_F64, + RTLIB::MUL_F80, + RTLIB::MUL_PPCF128), + NVT, Ops, 2, false/*sign irrelevant*/); +} + +SDOperand DAGTypeLegalizer::PromoteFloatRes_FSUB(SDNode *N) { + MVT NVT = TLI.getTypeToTransformTo(N->getValueType(0)); + SDOperand Ops[2] = { GetPromotedFloat(N->getOperand(0)), + GetPromotedFloat(N->getOperand(1)) }; + return MakeLibCall(GetFPLibCall(N->getValueType(0), + RTLIB::SUB_F32, + RTLIB::SUB_F64, + RTLIB::SUB_F80, + RTLIB::SUB_PPCF128), + NVT, Ops, 2, false/*sign irrelevant*/); +} + +SDOperand DAGTypeLegalizer::PromoteFloatRes_LOAD(SDNode *N) { + LoadSDNode *L = cast<LoadSDNode>(N); + MVT VT = N->getValueType(0); + MVT NVT = TLI.getTypeToTransformTo(VT); + + if (L->getExtensionType() == ISD::NON_EXTLOAD) + return DAG.getLoad(L->getAddressingMode(), L->getExtensionType(), + NVT, L->getChain(), L->getBasePtr(), L->getOffset(), + L->getSrcValue(), L->getSrcValueOffset(), NVT, + L->isVolatile(), L->getAlignment()); + + // Do a non-extending load followed by FP_EXTEND. + SDOperand NL = DAG.getLoad(L->getAddressingMode(), ISD::NON_EXTLOAD, + L->getMemoryVT(), L->getChain(), + L->getBasePtr(), L->getOffset(), + L->getSrcValue(), L->getSrcValueOffset(), + L->getMemoryVT(), + L->isVolatile(), L->getAlignment()); + return BitConvertToInteger(DAG.getNode(ISD::FP_EXTEND, VT, NL)); +} + +SDOperand DAGTypeLegalizer::PromoteFloatRes_XINT_TO_FP(SDNode *N) { + bool isSigned = N->getOpcode() == ISD::SINT_TO_FP; + MVT DestVT = N->getValueType(0); + SDOperand Op = N->getOperand(0); + + if (Op.getValueType() == MVT::i32) { + // simple 32-bit [signed|unsigned] integer to float/double expansion + + // Get the stack frame index of a 8 byte buffer. + SDOperand StackSlot = DAG.CreateStackTemporary(MVT::f64); + + // word offset constant for Hi/Lo address computation + SDOperand Offset = + DAG.getConstant(MVT(MVT::i32).getSizeInBits() / 8, + TLI.getPointerTy()); + // set up Hi and Lo (into buffer) address based on endian + SDOperand Hi = StackSlot; + SDOperand Lo = DAG.getNode(ISD::ADD, TLI.getPointerTy(), StackSlot, Offset); + if (TLI.isLittleEndian()) + std::swap(Hi, Lo); + + // if signed map to unsigned space + SDOperand OpMapped; + if (isSigned) { + // constant used to invert sign bit (signed to unsigned mapping) + SDOperand SignBit = DAG.getConstant(0x80000000u, MVT::i32); + OpMapped = DAG.getNode(ISD::XOR, MVT::i32, Op, SignBit); + } else { + OpMapped = Op; + } + // store the lo of the constructed double - based on integer input + SDOperand Store1 = DAG.getStore(DAG.getEntryNode(), + OpMapped, Lo, NULL, 0); + // initial hi portion of constructed double + SDOperand InitialHi = DAG.getConstant(0x43300000u, MVT::i32); + // store the hi of the constructed double - biased exponent + SDOperand Store2=DAG.getStore(Store1, InitialHi, Hi, NULL, 0); + // load the constructed double + SDOperand Load = DAG.getLoad(MVT::f64, Store2, StackSlot, NULL, 0); + // FP constant to bias correct the final result + SDOperand Bias = DAG.getConstantFP(isSigned ? + BitsToDouble(0x4330000080000000ULL) + : BitsToDouble(0x4330000000000000ULL), + MVT::f64); + // subtract the bias + SDOperand Sub = DAG.getNode(ISD::FSUB, MVT::f64, Load, Bias); + // final result + SDOperand Result; + // handle final rounding + if (DestVT == MVT::f64) { + // do nothing + Result = Sub; + } else if (DestVT.bitsLT(MVT::f64)) { + Result = DAG.getNode(ISD::FP_ROUND, DestVT, Sub, + DAG.getIntPtrConstant(0)); + } else if (DestVT.bitsGT(MVT::f64)) { + Result = DAG.getNode(ISD::FP_EXTEND, DestVT, Sub); + } + return BitConvertToInteger(Result); + } + assert(!isSigned && "Legalize cannot Expand SINT_TO_FP for i64 yet"); + SDOperand Tmp1 = DAG.getNode(ISD::SINT_TO_FP, DestVT, Op); + + SDOperand SignSet = DAG.getSetCC(TLI.getSetCCResultType(Op), Op, + DAG.getConstant(0, Op.getValueType()), + ISD::SETLT); + SDOperand Zero = DAG.getIntPtrConstant(0), Four = DAG.getIntPtrConstant(4); + SDOperand CstOffset = DAG.getNode(ISD::SELECT, Zero.getValueType(), + SignSet, Four, Zero); + + // If the sign bit of the integer is set, the large number will be treated + // as a negative number. To counteract this, the dynamic code adds an + // offset depending on the data type. + uint64_t FF; + switch (Op.getValueType().getSimpleVT()) { + default: assert(0 && "Unsupported integer type!"); + case MVT::i8 : FF = 0x43800000ULL; break; // 2^8 (as a float) + case MVT::i16: FF = 0x47800000ULL; break; // 2^16 (as a float) + case MVT::i32: FF = 0x4F800000ULL; break; // 2^32 (as a float) + case MVT::i64: FF = 0x5F800000ULL; break; // 2^64 (as a float) + } + if (TLI.isLittleEndian()) FF <<= 32; + static Constant *FudgeFactor = ConstantInt::get(Type::Int64Ty, FF); + + SDOperand CPIdx = DAG.getConstantPool(FudgeFactor, TLI.getPointerTy()); + CPIdx = DAG.getNode(ISD::ADD, TLI.getPointerTy(), CPIdx, CstOffset); + SDOperand FudgeInReg; + if (DestVT == MVT::f32) + FudgeInReg = DAG.getLoad(MVT::f32, DAG.getEntryNode(), CPIdx, + PseudoSourceValue::getConstantPool(), 0); + else { + FudgeInReg = DAG.getExtLoad(ISD::EXTLOAD, DestVT, + DAG.getEntryNode(), CPIdx, + PseudoSourceValue::getConstantPool(), 0, + MVT::f32); + } + + return BitConvertToInteger(DAG.getNode(ISD::FADD, DestVT, Tmp1, FudgeInReg)); +} + + +//===----------------------------------------------------------------------===// +// Operand Float to Integer Conversion.. +//===----------------------------------------------------------------------===// + +bool DAGTypeLegalizer::PromoteFloatOperand(SDNode *N, unsigned OpNo) { + DEBUG(cerr << "Promote float operand " << OpNo << ": "; N->dump(&DAG); + cerr << "\n"); + SDOperand Res(0, 0); + + // FIXME: Custom lowering for float-to-int? +#if 0 + if (TLI.getOperationAction(N->getOpcode(), N->getOperand(OpNo).getValueType()) + == TargetLowering::Custom) + Res = TLI.LowerOperation(SDOperand(N, 0), DAG); +#endif + + if (Res.Val == 0) { + switch (N->getOpcode()) { + default: +#ifndef NDEBUG + cerr << "PromoteFloatOperand Op #" << OpNo << ": "; + N->dump(&DAG); cerr << "\n"; +#endif + assert(0 && "Do not know how to convert this operator's operand!"); + abort(); + + case ISD::BIT_CONVERT: Res = PromoteFloatOp_BIT_CONVERT(N); break; + } + } + + // If the result is null, the sub-method took care of registering results etc. + if (!Res.Val) return false; + + // If the result is N, the sub-method updated N in place. Check to see if any + // operands are new, and if so, mark them. + if (Res.Val == N) { + // Mark N as new and remark N and its operands. This allows us to correctly + // revisit N if it needs another step of promotion and allows us to visit + // any new operands to N. + ReanalyzeNode(N); + return true; + } + + assert(Res.getValueType() == N->getValueType(0) && N->getNumValues() == 1 && + "Invalid operand expansion"); + + ReplaceValueWith(SDOperand(N, 0), Res); + return false; +} + +SDOperand DAGTypeLegalizer::PromoteFloatOp_BIT_CONVERT(SDNode *N) { + return DAG.getNode(ISD::BIT_CONVERT, N->getValueType(0), + GetPromotedFloat(N->getOperand(0))); +} + + +//===----------------------------------------------------------------------===// +// Float Result Expansion +//===----------------------------------------------------------------------===// + +/// ExpandFloatResult - This method is called when the specified result of the +/// specified node is found to need expansion. At this point, the node may also +/// have invalid operands or may have other results that need promotion, we just +/// know that (at least) one result needs expansion. +void DAGTypeLegalizer::ExpandFloatResult(SDNode *N, unsigned ResNo) { + DEBUG(cerr << "Expand float result: "; N->dump(&DAG); cerr << "\n"); + SDOperand Lo, Hi; + Lo = Hi = SDOperand(); + + // See if the target wants to custom expand this node. + if (TLI.getOperationAction(N->getOpcode(), N->getValueType(0)) == + TargetLowering::Custom) { + // If the target wants to, allow it to lower this itself. + if (SDNode *P = TLI.ExpandOperationResult(N, DAG)) { + // Everything that once used N now uses P. We are guaranteed that the + // result value types of N and the result value types of P match. + ReplaceNodeWith(N, P); + return; + } + } + + switch (N->getOpcode()) { + default: +#ifndef NDEBUG + cerr << "ExpandFloatResult #" << ResNo << ": "; + N->dump(&DAG); cerr << "\n"; +#endif + assert(0 && "Do not know how to expand the result of this operator!"); + abort(); + } + + // If Lo/Hi is null, the sub-method took care of registering results etc. + if (Lo.Val) + SetExpandedFloat(SDOperand(N, ResNo), Lo, Hi); +} + + +//===----------------------------------------------------------------------===// +// Float Operand Expansion +//===----------------------------------------------------------------------===// + +/// ExpandFloatOperand - This method is called when the specified operand of the +/// specified node is found to need expansion. At this point, all of the result +/// types of the node are known to be legal, but other operands of the node may +/// need promotion or expansion as well as the specified one. +bool DAGTypeLegalizer::ExpandFloatOperand(SDNode *N, unsigned OpNo) { + DEBUG(cerr << "Expand float operand: "; N->dump(&DAG); cerr << "\n"); + SDOperand Res(0, 0); + + if (TLI.getOperationAction(N->getOpcode(), N->getOperand(OpNo).getValueType()) + == TargetLowering::Custom) + Res = TLI.LowerOperation(SDOperand(N, 0), DAG); + + if (Res.Val == 0) { + switch (N->getOpcode()) { + default: + #ifndef NDEBUG + cerr << "ExpandFloatOperand Op #" << OpNo << ": "; + N->dump(&DAG); cerr << "\n"; + #endif + assert(0 && "Do not know how to expand this operator's operand!"); + abort(); + } + } + + // If the result is null, the sub-method took care of registering results etc. + if (!Res.Val) return false; + // If the result is N, the sub-method updated N in place. Check to see if any + // operands are new, and if so, mark them. + if (Res.Val == N) { + // Mark N as new and remark N and its operands. This allows us to correctly + // revisit N if it needs another step of expansion and allows us to visit + // any new operands to N. + ReanalyzeNode(N); + return true; + } + + assert(Res.getValueType() == N->getValueType(0) && N->getNumValues() == 1 && + "Invalid operand expansion"); + + ReplaceValueWith(SDOperand(N, 0), Res); + return false; +} |