diff options
Diffstat (limited to 'lib/Target/Alpha/AlphaISelDAGToDAG.cpp')
-rw-r--r-- | lib/Target/Alpha/AlphaISelDAGToDAG.cpp | 553 |
1 files changed, 553 insertions, 0 deletions
diff --git a/lib/Target/Alpha/AlphaISelDAGToDAG.cpp b/lib/Target/Alpha/AlphaISelDAGToDAG.cpp new file mode 100644 index 0000000..affcd3e --- /dev/null +++ b/lib/Target/Alpha/AlphaISelDAGToDAG.cpp @@ -0,0 +1,553 @@ +//===-- AlphaISelDAGToDAG.cpp - Alpha pattern matching inst selector ------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file defines a pattern matching instruction selector for Alpha, +// converting from a legalized dag to a Alpha dag. +// +//===----------------------------------------------------------------------===// + +#include "Alpha.h" +#include "AlphaTargetMachine.h" +#include "AlphaISelLowering.h" +#include "llvm/CodeGen/MachineInstrBuilder.h" +#include "llvm/CodeGen/MachineFrameInfo.h" +#include "llvm/CodeGen/MachineFunction.h" +#include "llvm/CodeGen/MachineRegisterInfo.h" +#include "llvm/CodeGen/SelectionDAG.h" +#include "llvm/CodeGen/SelectionDAGISel.h" +#include "llvm/Target/TargetOptions.h" +#include "llvm/Constants.h" +#include "llvm/DerivedTypes.h" +#include "llvm/GlobalValue.h" +#include "llvm/Intrinsics.h" +#include "llvm/Support/Compiler.h" +#include "llvm/Support/Debug.h" +#include "llvm/Support/MathExtras.h" +#include <algorithm> +using namespace llvm; + +namespace { + + //===--------------------------------------------------------------------===// + /// AlphaDAGToDAGISel - Alpha specific code to select Alpha machine + /// instructions for SelectionDAG operations. + class AlphaDAGToDAGISel : public SelectionDAGISel { + static const int64_t IMM_LOW = -32768; + static const int64_t IMM_HIGH = 32767; + static const int64_t IMM_MULT = 65536; + static const int64_t IMM_FULLHIGH = IMM_HIGH + IMM_HIGH * IMM_MULT; + static const int64_t IMM_FULLLOW = IMM_LOW + IMM_LOW * IMM_MULT; + + static int64_t get_ldah16(int64_t x) { + int64_t y = x / IMM_MULT; + if (x % IMM_MULT > IMM_HIGH) + ++y; + return y; + } + + static int64_t get_lda16(int64_t x) { + return x - get_ldah16(x) * IMM_MULT; + } + + /// get_zapImm - Return a zap mask if X is a valid immediate for a zapnot + /// instruction (if not, return 0). Note that this code accepts partial + /// zap masks. For example (and LHS, 1) is a valid zap, as long we know + /// that the bits 1-7 of LHS are already zero. If LHS is non-null, we are + /// in checking mode. If LHS is null, we assume that the mask has already + /// been validated before. + uint64_t get_zapImm(SDValue LHS, uint64_t Constant) { + uint64_t BitsToCheck = 0; + unsigned Result = 0; + for (unsigned i = 0; i != 8; ++i) { + if (((Constant >> 8*i) & 0xFF) == 0) { + // nothing to do. + } else { + Result |= 1 << i; + if (((Constant >> 8*i) & 0xFF) == 0xFF) { + // If the entire byte is set, zapnot the byte. + } else if (LHS.getNode() == 0) { + // Otherwise, if the mask was previously validated, we know its okay + // to zapnot this entire byte even though all the bits aren't set. + } else { + // Otherwise we don't know that the it's okay to zapnot this entire + // byte. Only do this iff we can prove that the missing bits are + // already null, so the bytezap doesn't need to really null them. + BitsToCheck |= ~Constant & (0xFF << 8*i); + } + } + } + + // If there are missing bits in a byte (for example, X & 0xEF00), check to + // see if the missing bits (0x1000) are already known zero if not, the zap + // isn't okay to do, as it won't clear all the required bits. + if (BitsToCheck && + !CurDAG->MaskedValueIsZero(LHS, + APInt(LHS.getValueSizeInBits(), + BitsToCheck))) + return 0; + + return Result; + } + + static uint64_t get_zapImm(uint64_t x) { + unsigned build = 0; + for(int i = 0; i != 8; ++i) { + if ((x & 0x00FF) == 0x00FF) + build |= 1 << i; + else if ((x & 0x00FF) != 0) + return 0; + x >>= 8; + } + return build; + } + + + static uint64_t getNearPower2(uint64_t x) { + if (!x) return 0; + unsigned at = CountLeadingZeros_64(x); + uint64_t complow = 1 << (63 - at); + uint64_t comphigh = 1 << (64 - at); + //cerr << x << ":" << complow << ":" << comphigh << "\n"; + if (abs(complow - x) <= abs(comphigh - x)) + return complow; + else + return comphigh; + } + + static bool chkRemNearPower2(uint64_t x, uint64_t r, bool swap) { + uint64_t y = getNearPower2(x); + if (swap) + return (y - x) == r; + else + return (x - y) == r; + } + + static bool isFPZ(SDValue N) { + ConstantFPSDNode *CN = dyn_cast<ConstantFPSDNode>(N); + return (CN && (CN->getValueAPF().isZero())); + } + static bool isFPZn(SDValue N) { + ConstantFPSDNode *CN = dyn_cast<ConstantFPSDNode>(N); + return (CN && CN->getValueAPF().isNegZero()); + } + static bool isFPZp(SDValue N) { + ConstantFPSDNode *CN = dyn_cast<ConstantFPSDNode>(N); + return (CN && CN->getValueAPF().isPosZero()); + } + + public: + explicit AlphaDAGToDAGISel(AlphaTargetMachine &TM) + : SelectionDAGISel(TM) + {} + + /// getI64Imm - Return a target constant with the specified value, of type + /// i64. + inline SDValue getI64Imm(int64_t Imm) { + return CurDAG->getTargetConstant(Imm, MVT::i64); + } + + // Select - Convert the specified operand from a target-independent to a + // target-specific node if it hasn't already been changed. + SDNode *Select(SDValue Op); + + /// InstructionSelect - This callback is invoked by + /// SelectionDAGISel when it has created a SelectionDAG for us to codegen. + virtual void InstructionSelect(); + + virtual const char *getPassName() const { + return "Alpha DAG->DAG Pattern Instruction Selection"; + } + + /// SelectInlineAsmMemoryOperand - Implement addressing mode selection for + /// inline asm expressions. + virtual bool SelectInlineAsmMemoryOperand(const SDValue &Op, + char ConstraintCode, + std::vector<SDValue> &OutOps) { + SDValue Op0; + switch (ConstraintCode) { + default: return true; + case 'm': // memory + Op0 = Op; + break; + } + + OutOps.push_back(Op0); + return false; + } + +// Include the pieces autogenerated from the target description. +#include "AlphaGenDAGISel.inc" + +private: + SDValue getGlobalBaseReg(); + SDValue getGlobalRetAddr(); + void SelectCALL(SDValue Op); + + }; +} + +/// getGlobalBaseReg - Output the instructions required to put the +/// GOT address into a register. +/// +SDValue AlphaDAGToDAGISel::getGlobalBaseReg() { + unsigned GP = 0; + for(MachineRegisterInfo::livein_iterator ii = RegInfo->livein_begin(), + ee = RegInfo->livein_end(); ii != ee; ++ii) + if (ii->first == Alpha::R29) { + GP = ii->second; + break; + } + assert(GP && "GOT PTR not in liveins"); + // FIXME is there anywhere sensible to get a DebugLoc here? + return CurDAG->getCopyFromReg(CurDAG->getEntryNode(), + DebugLoc::getUnknownLoc(), GP, MVT::i64); +} + +/// getRASaveReg - Grab the return address +/// +SDValue AlphaDAGToDAGISel::getGlobalRetAddr() { + unsigned RA = 0; + for(MachineRegisterInfo::livein_iterator ii = RegInfo->livein_begin(), + ee = RegInfo->livein_end(); ii != ee; ++ii) + if (ii->first == Alpha::R26) { + RA = ii->second; + break; + } + assert(RA && "RA PTR not in liveins"); + // FIXME is there anywhere sensible to get a DebugLoc here? + return CurDAG->getCopyFromReg(CurDAG->getEntryNode(), + DebugLoc::getUnknownLoc(), RA, MVT::i64); +} + +/// InstructionSelect - This callback is invoked by +/// SelectionDAGISel when it has created a SelectionDAG for us to codegen. +void AlphaDAGToDAGISel::InstructionSelect() { + DEBUG(BB->dump()); + + // Select target instructions for the DAG. + SelectRoot(*CurDAG); + CurDAG->RemoveDeadNodes(); +} + +// Select - Convert the specified operand from a target-independent to a +// target-specific node if it hasn't already been changed. +SDNode *AlphaDAGToDAGISel::Select(SDValue Op) { + SDNode *N = Op.getNode(); + if (N->isMachineOpcode()) { + return NULL; // Already selected. + } + DebugLoc dl = N->getDebugLoc(); + + switch (N->getOpcode()) { + default: break; + case AlphaISD::CALL: + SelectCALL(Op); + return NULL; + + case ISD::FrameIndex: { + int FI = cast<FrameIndexSDNode>(N)->getIndex(); + return CurDAG->SelectNodeTo(N, Alpha::LDA, MVT::i64, + CurDAG->getTargetFrameIndex(FI, MVT::i32), + getI64Imm(0)); + } + case ISD::GLOBAL_OFFSET_TABLE: { + SDValue Result = getGlobalBaseReg(); + ReplaceUses(Op, Result); + return NULL; + } + case AlphaISD::GlobalRetAddr: { + SDValue Result = getGlobalRetAddr(); + ReplaceUses(Op, Result); + return NULL; + } + + case AlphaISD::DivCall: { + SDValue Chain = CurDAG->getEntryNode(); + SDValue N0 = Op.getOperand(0); + SDValue N1 = Op.getOperand(1); + SDValue N2 = Op.getOperand(2); + Chain = CurDAG->getCopyToReg(Chain, dl, Alpha::R24, N1, + SDValue(0,0)); + Chain = CurDAG->getCopyToReg(Chain, dl, Alpha::R25, N2, + Chain.getValue(1)); + Chain = CurDAG->getCopyToReg(Chain, dl, Alpha::R27, N0, + Chain.getValue(1)); + SDNode *CNode = + CurDAG->getTargetNode(Alpha::JSRs, dl, MVT::Other, MVT::Flag, + Chain, Chain.getValue(1)); + Chain = CurDAG->getCopyFromReg(Chain, dl, Alpha::R27, MVT::i64, + SDValue(CNode, 1)); + return CurDAG->SelectNodeTo(N, Alpha::BISr, MVT::i64, Chain, Chain); + } + + case ISD::READCYCLECOUNTER: { + SDValue Chain = N->getOperand(0); + return CurDAG->getTargetNode(Alpha::RPCC, dl, MVT::i64, MVT::Other, + Chain); + } + + case ISD::Constant: { + uint64_t uval = cast<ConstantSDNode>(N)->getZExtValue(); + + if (uval == 0) { + SDValue Result = CurDAG->getCopyFromReg(CurDAG->getEntryNode(), dl, + Alpha::R31, MVT::i64); + ReplaceUses(Op, Result); + return NULL; + } + + int64_t val = (int64_t)uval; + int32_t val32 = (int32_t)val; + if (val <= IMM_HIGH + IMM_HIGH * IMM_MULT && + val >= IMM_LOW + IMM_LOW * IMM_MULT) + break; //(LDAH (LDA)) + if ((uval >> 32) == 0 && //empty upper bits + val32 <= IMM_HIGH + IMM_HIGH * IMM_MULT) + // val32 >= IMM_LOW + IMM_LOW * IMM_MULT) //always true + break; //(zext (LDAH (LDA))) + //Else use the constant pool + ConstantInt *C = ConstantInt::get(Type::Int64Ty, uval); + SDValue CPI = CurDAG->getTargetConstantPool(C, MVT::i64); + SDNode *Tmp = CurDAG->getTargetNode(Alpha::LDAHr, dl, MVT::i64, CPI, + getGlobalBaseReg()); + return CurDAG->SelectNodeTo(N, Alpha::LDQr, MVT::i64, MVT::Other, + CPI, SDValue(Tmp, 0), CurDAG->getEntryNode()); + } + case ISD::TargetConstantFP: + case ISD::ConstantFP: { + ConstantFPSDNode *CN = cast<ConstantFPSDNode>(N); + bool isDouble = N->getValueType(0) == MVT::f64; + MVT T = isDouble ? MVT::f64 : MVT::f32; + if (CN->getValueAPF().isPosZero()) { + return CurDAG->SelectNodeTo(N, isDouble ? Alpha::CPYST : Alpha::CPYSS, + T, CurDAG->getRegister(Alpha::F31, T), + CurDAG->getRegister(Alpha::F31, T)); + } else if (CN->getValueAPF().isNegZero()) { + return CurDAG->SelectNodeTo(N, isDouble ? Alpha::CPYSNT : Alpha::CPYSNS, + T, CurDAG->getRegister(Alpha::F31, T), + CurDAG->getRegister(Alpha::F31, T)); + } else { + abort(); + } + break; + } + + case ISD::SETCC: + if (N->getOperand(0).getNode()->getValueType(0).isFloatingPoint()) { + ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(2))->get(); + + unsigned Opc = Alpha::WTF; + bool rev = false; + bool inv = false; + switch(CC) { + default: DEBUG(N->dump(CurDAG)); assert(0 && "Unknown FP comparison!"); + case ISD::SETEQ: case ISD::SETOEQ: case ISD::SETUEQ: + Opc = Alpha::CMPTEQ; break; + case ISD::SETLT: case ISD::SETOLT: case ISD::SETULT: + Opc = Alpha::CMPTLT; break; + case ISD::SETLE: case ISD::SETOLE: case ISD::SETULE: + Opc = Alpha::CMPTLE; break; + case ISD::SETGT: case ISD::SETOGT: case ISD::SETUGT: + Opc = Alpha::CMPTLT; rev = true; break; + case ISD::SETGE: case ISD::SETOGE: case ISD::SETUGE: + Opc = Alpha::CMPTLE; rev = true; break; + case ISD::SETNE: case ISD::SETONE: case ISD::SETUNE: + Opc = Alpha::CMPTEQ; inv = true; break; + case ISD::SETO: + Opc = Alpha::CMPTUN; inv = true; break; + case ISD::SETUO: + Opc = Alpha::CMPTUN; break; + }; + SDValue tmp1 = N->getOperand(rev?1:0); + SDValue tmp2 = N->getOperand(rev?0:1); + SDNode *cmp = CurDAG->getTargetNode(Opc, dl, MVT::f64, tmp1, tmp2); + if (inv) + cmp = CurDAG->getTargetNode(Alpha::CMPTEQ, dl, + MVT::f64, SDValue(cmp, 0), + CurDAG->getRegister(Alpha::F31, MVT::f64)); + switch(CC) { + case ISD::SETUEQ: case ISD::SETULT: case ISD::SETULE: + case ISD::SETUNE: case ISD::SETUGT: case ISD::SETUGE: + { + SDNode* cmp2 = CurDAG->getTargetNode(Alpha::CMPTUN, dl, MVT::f64, + tmp1, tmp2); + cmp = CurDAG->getTargetNode(Alpha::ADDT, dl, MVT::f64, + SDValue(cmp2, 0), SDValue(cmp, 0)); + break; + } + default: break; + } + + SDNode* LD = CurDAG->getTargetNode(Alpha::FTOIT, dl, + MVT::i64, SDValue(cmp, 0)); + return CurDAG->getTargetNode(Alpha::CMPULT, dl, MVT::i64, + CurDAG->getRegister(Alpha::R31, MVT::i64), + SDValue(LD,0)); + } + break; + + case ISD::SELECT: + if (N->getValueType(0).isFloatingPoint() && + (N->getOperand(0).getOpcode() != ISD::SETCC || + !N->getOperand(0).getOperand(1).getValueType().isFloatingPoint())) { + //This should be the condition not covered by the Patterns + //FIXME: Don't have SelectCode die, but rather return something testable + // so that things like this can be caught in fall though code + //move int to fp + bool isDouble = N->getValueType(0) == MVT::f64; + SDValue cond = N->getOperand(0); + SDValue TV = N->getOperand(1); + SDValue FV = N->getOperand(2); + + SDNode* LD = CurDAG->getTargetNode(Alpha::ITOFT, dl, MVT::f64, cond); + return CurDAG->getTargetNode(isDouble?Alpha::FCMOVNET:Alpha::FCMOVNES, + dl, MVT::f64, FV, TV, SDValue(LD,0)); + } + break; + + case ISD::AND: { + ConstantSDNode* SC = NULL; + ConstantSDNode* MC = NULL; + if (N->getOperand(0).getOpcode() == ISD::SRL && + (MC = dyn_cast<ConstantSDNode>(N->getOperand(1))) && + (SC = dyn_cast<ConstantSDNode>(N->getOperand(0).getOperand(1)))) { + uint64_t sval = SC->getZExtValue(); + uint64_t mval = MC->getZExtValue(); + // If the result is a zap, let the autogened stuff handle it. + if (get_zapImm(N->getOperand(0), mval)) + break; + // given mask X, and shift S, we want to see if there is any zap in the + // mask if we play around with the botton S bits + uint64_t dontcare = (~0ULL) >> (64 - sval); + uint64_t mask = mval << sval; + + if (get_zapImm(mask | dontcare)) + mask = mask | dontcare; + + if (get_zapImm(mask)) { + SDValue Z = + SDValue(CurDAG->getTargetNode(Alpha::ZAPNOTi, dl, MVT::i64, + N->getOperand(0).getOperand(0), + getI64Imm(get_zapImm(mask))), 0); + return CurDAG->getTargetNode(Alpha::SRLr, dl, MVT::i64, Z, + getI64Imm(sval)); + } + } + break; + } + + } + + return SelectCode(Op); +} + +void AlphaDAGToDAGISel::SelectCALL(SDValue Op) { + //TODO: add flag stuff to prevent nondeturministic breakage! + + SDNode *N = Op.getNode(); + SDValue Chain = N->getOperand(0); + SDValue Addr = N->getOperand(1); + SDValue InFlag(0,0); // Null incoming flag value. + DebugLoc dl = N->getDebugLoc(); + + std::vector<SDValue> CallOperands; + std::vector<MVT> TypeOperands; + + //grab the arguments + for(int i = 2, e = N->getNumOperands(); i < e; ++i) { + TypeOperands.push_back(N->getOperand(i).getValueType()); + CallOperands.push_back(N->getOperand(i)); + } + int count = N->getNumOperands() - 2; + + static const unsigned args_int[] = {Alpha::R16, Alpha::R17, Alpha::R18, + Alpha::R19, Alpha::R20, Alpha::R21}; + static const unsigned args_float[] = {Alpha::F16, Alpha::F17, Alpha::F18, + Alpha::F19, Alpha::F20, Alpha::F21}; + + for (int i = 6; i < count; ++i) { + unsigned Opc = Alpha::WTF; + if (TypeOperands[i].isInteger()) { + Opc = Alpha::STQ; + } else if (TypeOperands[i] == MVT::f32) { + Opc = Alpha::STS; + } else if (TypeOperands[i] == MVT::f64) { + Opc = Alpha::STT; + } else + assert(0 && "Unknown operand"); + + SDValue Ops[] = { CallOperands[i], getI64Imm((i - 6) * 8), + CurDAG->getCopyFromReg(Chain, dl, Alpha::R30, MVT::i64), + Chain }; + Chain = SDValue(CurDAG->getTargetNode(Opc, dl, MVT::Other, Ops, 4), 0); + } + for (int i = 0; i < std::min(6, count); ++i) { + if (TypeOperands[i].isInteger()) { + Chain = CurDAG->getCopyToReg(Chain, dl, args_int[i], + CallOperands[i], InFlag); + InFlag = Chain.getValue(1); + } else if (TypeOperands[i] == MVT::f32 || TypeOperands[i] == MVT::f64) { + Chain = CurDAG->getCopyToReg(Chain, dl, args_float[i], + CallOperands[i], InFlag); + InFlag = Chain.getValue(1); + } else + assert(0 && "Unknown operand"); + } + + // Finally, once everything is in registers to pass to the call, emit the + // call itself. + if (Addr.getOpcode() == AlphaISD::GPRelLo) { + SDValue GOT = getGlobalBaseReg(); + Chain = CurDAG->getCopyToReg(Chain, dl, Alpha::R29, GOT, InFlag); + InFlag = Chain.getValue(1); + Chain = SDValue(CurDAG->getTargetNode(Alpha::BSR, dl, MVT::Other, + MVT::Flag, Addr.getOperand(0), + Chain, InFlag), 0); + } else { + Chain = CurDAG->getCopyToReg(Chain, dl, Alpha::R27, Addr, InFlag); + InFlag = Chain.getValue(1); + Chain = SDValue(CurDAG->getTargetNode(Alpha::JSR, dl, MVT::Other, + MVT::Flag, Chain, InFlag), 0); + } + InFlag = Chain.getValue(1); + + std::vector<SDValue> CallResults; + + switch (N->getValueType(0).getSimpleVT()) { + default: assert(0 && "Unexpected ret value!"); + case MVT::Other: break; + case MVT::i64: + Chain = CurDAG->getCopyFromReg(Chain, dl, + Alpha::R0, MVT::i64, InFlag).getValue(1); + CallResults.push_back(Chain.getValue(0)); + break; + case MVT::f32: + Chain = CurDAG->getCopyFromReg(Chain, dl, + Alpha::F0, MVT::f32, InFlag).getValue(1); + CallResults.push_back(Chain.getValue(0)); + break; + case MVT::f64: + Chain = CurDAG->getCopyFromReg(Chain, dl, + Alpha::F0, MVT::f64, InFlag).getValue(1); + CallResults.push_back(Chain.getValue(0)); + break; + } + + CallResults.push_back(Chain); + for (unsigned i = 0, e = CallResults.size(); i != e; ++i) + ReplaceUses(Op.getValue(i), CallResults[i]); +} + + +/// createAlphaISelDag - This pass converts a legalized DAG into a +/// Alpha-specific DAG, ready for instruction scheduling. +/// +FunctionPass *llvm::createAlphaISelDag(AlphaTargetMachine &TM) { + return new AlphaDAGToDAGISel(TM); +} |