diff options
Diffstat (limited to 'contrib/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp')
| -rw-r--r-- | contrib/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp | 225 |
1 files changed, 185 insertions, 40 deletions
diff --git a/contrib/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp b/contrib/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp index e6108c3..1616ff1 100644 --- a/contrib/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp +++ b/contrib/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp @@ -76,6 +76,9 @@ cl::opt<bool> EnableAArch64ELFLocalDynamicTLSGeneration( cl::desc("Allow AArch64 Local Dynamic TLS code generation"), cl::init(false)); +/// Value type used for condition codes. +static const MVT MVT_CC = MVT::i32; + AArch64TargetLowering::AArch64TargetLowering(const TargetMachine &TM, const AArch64Subtarget &STI) : TargetLowering(TM), Subtarget(&STI) { @@ -807,6 +810,9 @@ const char *AArch64TargetLowering::getTargetNodeName(unsigned Opcode) const { case AArch64ISD::ADCS: return "AArch64ISD::ADCS"; case AArch64ISD::SBCS: return "AArch64ISD::SBCS"; case AArch64ISD::ANDS: return "AArch64ISD::ANDS"; + case AArch64ISD::CCMP: return "AArch64ISD::CCMP"; + case AArch64ISD::CCMN: return "AArch64ISD::CCMN"; + case AArch64ISD::FCCMP: return "AArch64ISD::FCCMP"; case AArch64ISD::FCMP: return "AArch64ISD::FCMP"; case AArch64ISD::FMIN: return "AArch64ISD::FMIN"; case AArch64ISD::FMAX: return "AArch64ISD::FMAX"; @@ -1165,10 +1171,133 @@ static SDValue emitComparison(SDValue LHS, SDValue RHS, ISD::CondCode CC, LHS = LHS.getOperand(0); } - return DAG.getNode(Opcode, dl, DAG.getVTList(VT, MVT::i32), LHS, RHS) + return DAG.getNode(Opcode, dl, DAG.getVTList(VT, MVT_CC), LHS, RHS) .getValue(1); } +static SDValue emitConditionalComparison(SDValue LHS, SDValue RHS, + ISD::CondCode CC, SDValue CCOp, + SDValue Condition, unsigned NZCV, + SDLoc DL, SelectionDAG &DAG) { + unsigned Opcode = 0; + if (LHS.getValueType().isFloatingPoint()) + Opcode = AArch64ISD::FCCMP; + else if (RHS.getOpcode() == ISD::SUB) { + SDValue SubOp0 = RHS.getOperand(0); + if (const ConstantSDNode *SubOp0C = dyn_cast<ConstantSDNode>(SubOp0)) + if (SubOp0C->isNullValue() && (CC == ISD::SETEQ || CC == ISD::SETNE)) { + // See emitComparison() on why we can only do this for SETEQ and SETNE. + Opcode = AArch64ISD::CCMN; + RHS = RHS.getOperand(1); + } + } + if (Opcode == 0) + Opcode = AArch64ISD::CCMP; + + SDValue NZCVOp = DAG.getConstant(NZCV, DL, MVT::i32); + return DAG.getNode(Opcode, DL, MVT_CC, LHS, RHS, NZCVOp, Condition, CCOp); +} + +/// Returns true if @p Val is a tree of AND/OR/SETCC operations. +static bool isConjunctionDisjunctionTree(const SDValue Val, unsigned Depth) { + if (!Val.hasOneUse()) + return false; + if (Val->getOpcode() == ISD::SETCC) + return true; + // Protect against stack overflow. + if (Depth > 1000) + return false; + if (Val->getOpcode() == ISD::AND || Val->getOpcode() == ISD::OR) { + SDValue O0 = Val->getOperand(0); + SDValue O1 = Val->getOperand(1); + return isConjunctionDisjunctionTree(O0, Depth+1) && + isConjunctionDisjunctionTree(O1, Depth+1); + } + return false; +} + +/// Emit conjunction or disjunction tree with the CMP/FCMP followed by a chain +/// of CCMP/CFCMP ops. For example (SETCC_0 & SETCC_1) with condition cond0 and +/// cond1 can be transformed into "CMP; CCMP" with CCMP executing on cond_0 +/// and setting flags to inversed(cond_1) otherwise. +/// This recursive function produces DAG nodes that produce condition flags +/// suitable to determine the truth value of @p Val (which is AND/OR/SETCC) +/// by testing the result for the condition set to @p OutCC. If @p Negate is +/// set the opposite truth value is produced. If @p CCOp and @p Condition are +/// given then conditional comparison are created so that false is reported +/// when they are false. +static SDValue emitConjunctionDisjunctionTree( + SelectionDAG &DAG, SDValue Val, AArch64CC::CondCode &OutCC, bool Negate, + SDValue CCOp = SDValue(), AArch64CC::CondCode Condition = AArch64CC::AL) { + assert(isConjunctionDisjunctionTree(Val, 0)); + // We're at a tree leaf, produce a c?f?cmp. + unsigned Opcode = Val->getOpcode(); + if (Opcode == ISD::SETCC) { + SDValue LHS = Val->getOperand(0); + SDValue RHS = Val->getOperand(1); + ISD::CondCode CC = cast<CondCodeSDNode>(Val->getOperand(2))->get(); + bool isInteger = LHS.getValueType().isInteger(); + if (Negate) + CC = getSetCCInverse(CC, isInteger); + SDLoc DL(Val); + // Determine OutCC and handle FP special case. + if (isInteger) { + OutCC = changeIntCCToAArch64CC(CC); + } else { + assert(LHS.getValueType().isFloatingPoint()); + AArch64CC::CondCode ExtraCC; + changeFPCCToAArch64CC(CC, OutCC, ExtraCC); + // Surpisingly some floating point conditions can't be tested with a + // single condition code. Construct an additional comparison in this case. + // See comment below on how we deal with OR conditions. + if (ExtraCC != AArch64CC::AL) { + SDValue ExtraCmp; + if (!CCOp.getNode()) + ExtraCmp = emitComparison(LHS, RHS, CC, DL, DAG); + else { + SDValue ConditionOp = DAG.getConstant(Condition, DL, MVT_CC); + // Note that we want the inverse of ExtraCC, so NZCV is not inversed. + unsigned NZCV = AArch64CC::getNZCVToSatisfyCondCode(ExtraCC); + ExtraCmp = emitConditionalComparison(LHS, RHS, CC, CCOp, ConditionOp, + NZCV, DL, DAG); + } + CCOp = ExtraCmp; + Condition = AArch64CC::getInvertedCondCode(ExtraCC); + OutCC = AArch64CC::getInvertedCondCode(OutCC); + } + } + + // Produce a normal comparison if we are first in the chain + if (!CCOp.getNode()) + return emitComparison(LHS, RHS, CC, DL, DAG); + // Otherwise produce a ccmp. + SDValue ConditionOp = DAG.getConstant(Condition, DL, MVT_CC); + AArch64CC::CondCode InvOutCC = AArch64CC::getInvertedCondCode(OutCC); + unsigned NZCV = AArch64CC::getNZCVToSatisfyCondCode(InvOutCC); + return emitConditionalComparison(LHS, RHS, CC, CCOp, ConditionOp, NZCV, DL, + DAG); + } + + // Construct comparison sequence for the left hand side. + SDValue LHS = Val->getOperand(0); + SDValue RHS = Val->getOperand(1); + + // We can only implement AND-like behaviour here, but negation is free. So we + // use (not (and (not x) (not y))) to implement (or x y). + bool isOr = Val->getOpcode() == ISD::OR; + assert((isOr || Val->getOpcode() == ISD::AND) && "Should have AND or OR."); + Negate ^= isOr; + + AArch64CC::CondCode RHSCC; + SDValue CmpR = + emitConjunctionDisjunctionTree(DAG, RHS, RHSCC, isOr, CCOp, Condition); + SDValue CmpL = + emitConjunctionDisjunctionTree(DAG, LHS, OutCC, isOr, CmpR, RHSCC); + if (Negate) + OutCC = AArch64CC::getInvertedCondCode(OutCC); + return CmpL; +} + static SDValue getAArch64Cmp(SDValue LHS, SDValue RHS, ISD::CondCode CC, SDValue &AArch64cc, SelectionDAG &DAG, SDLoc dl) { SDValue Cmp; @@ -1227,47 +1356,55 @@ static SDValue getAArch64Cmp(SDValue LHS, SDValue RHS, ISD::CondCode CC, } } } - // The imm operand of ADDS is an unsigned immediate, in the range 0 to 4095. - // For the i8 operand, the largest immediate is 255, so this can be easily - // encoded in the compare instruction. For the i16 operand, however, the - // largest immediate cannot be encoded in the compare. - // Therefore, use a sign extending load and cmn to avoid materializing the -1 - // constant. For example, - // movz w1, #65535 - // ldrh w0, [x0, #0] - // cmp w0, w1 - // > - // ldrsh w0, [x0, #0] - // cmn w0, #1 - // Fundamental, we're relying on the property that (zext LHS) == (zext RHS) - // if and only if (sext LHS) == (sext RHS). The checks are in place to ensure - // both the LHS and RHS are truely zero extended and to make sure the - // transformation is profitable. if ((CC == ISD::SETEQ || CC == ISD::SETNE) && isa<ConstantSDNode>(RHS)) { - if ((cast<ConstantSDNode>(RHS)->getZExtValue() >> 16 == 0) && - isa<LoadSDNode>(LHS)) { - if (cast<LoadSDNode>(LHS)->getExtensionType() == ISD::ZEXTLOAD && - cast<LoadSDNode>(LHS)->getMemoryVT() == MVT::i16 && - LHS.getNode()->hasNUsesOfValue(1, 0)) { - int16_t ValueofRHS = cast<ConstantSDNode>(RHS)->getZExtValue(); - if (ValueofRHS < 0 && isLegalArithImmed(-ValueofRHS)) { - SDValue SExt = - DAG.getNode(ISD::SIGN_EXTEND_INREG, dl, LHS.getValueType(), LHS, - DAG.getValueType(MVT::i16)); - Cmp = emitComparison(SExt, - DAG.getConstant(ValueofRHS, dl, - RHS.getValueType()), - CC, dl, DAG); - AArch64CC = changeIntCCToAArch64CC(CC); - AArch64cc = DAG.getConstant(AArch64CC, dl, MVT::i32); - return Cmp; - } + const ConstantSDNode *RHSC = cast<ConstantSDNode>(RHS); + + // The imm operand of ADDS is an unsigned immediate, in the range 0 to 4095. + // For the i8 operand, the largest immediate is 255, so this can be easily + // encoded in the compare instruction. For the i16 operand, however, the + // largest immediate cannot be encoded in the compare. + // Therefore, use a sign extending load and cmn to avoid materializing the + // -1 constant. For example, + // movz w1, #65535 + // ldrh w0, [x0, #0] + // cmp w0, w1 + // > + // ldrsh w0, [x0, #0] + // cmn w0, #1 + // Fundamental, we're relying on the property that (zext LHS) == (zext RHS) + // if and only if (sext LHS) == (sext RHS). The checks are in place to + // ensure both the LHS and RHS are truely zero extended and to make sure the + // transformation is profitable. + if ((RHSC->getZExtValue() >> 16 == 0) && isa<LoadSDNode>(LHS) && + cast<LoadSDNode>(LHS)->getExtensionType() == ISD::ZEXTLOAD && + cast<LoadSDNode>(LHS)->getMemoryVT() == MVT::i16 && + LHS.getNode()->hasNUsesOfValue(1, 0)) { + int16_t ValueofRHS = cast<ConstantSDNode>(RHS)->getZExtValue(); + if (ValueofRHS < 0 && isLegalArithImmed(-ValueofRHS)) { + SDValue SExt = + DAG.getNode(ISD::SIGN_EXTEND_INREG, dl, LHS.getValueType(), LHS, + DAG.getValueType(MVT::i16)); + Cmp = emitComparison(SExt, DAG.getConstant(ValueofRHS, dl, + RHS.getValueType()), + CC, dl, DAG); + AArch64CC = changeIntCCToAArch64CC(CC); + goto CreateCCNode; } } + + if ((RHSC->isNullValue() || RHSC->isOne()) && + isConjunctionDisjunctionTree(LHS, 0)) { + bool Negate = (CC == ISD::SETNE) ^ RHSC->isNullValue(); + Cmp = emitConjunctionDisjunctionTree(DAG, LHS, AArch64CC, Negate); + goto CreateCCNode; + } } + Cmp = emitComparison(LHS, RHS, CC, dl, DAG); AArch64CC = changeIntCCToAArch64CC(CC); - AArch64cc = DAG.getConstant(AArch64CC, dl, MVT::i32); + +CreateCCNode: + AArch64cc = DAG.getConstant(AArch64CC, dl, MVT_CC); return Cmp; } @@ -4065,7 +4202,8 @@ unsigned AArch64TargetLowering::getRegisterByName(const char* RegName, .Default(0); if (Reg) return Reg; - report_fatal_error("Invalid register name global variable"); + report_fatal_error(Twine("Invalid register name \"" + + StringRef(RegName) + "\".")); } SDValue AArch64TargetLowering::LowerRETURNADDR(SDValue Op, @@ -6741,7 +6879,8 @@ bool AArch64TargetLowering::isLegalICmpImmediate(int64_t Immed) const { /// isLegalAddressingMode - Return true if the addressing mode represented /// by AM is legal for this target, for a load/store of the specified type. bool AArch64TargetLowering::isLegalAddressingMode(const AddrMode &AM, - Type *Ty) const { + Type *Ty, + unsigned AS) const { // AArch64 has five basic addressing modes: // reg // reg + 9-bit signed offset @@ -6792,7 +6931,8 @@ bool AArch64TargetLowering::isLegalAddressingMode(const AddrMode &AM, } int AArch64TargetLowering::getScalingFactorCost(const AddrMode &AM, - Type *Ty) const { + Type *Ty, + unsigned AS) const { // Scaling factors are not free at all. // Operands | Rt Latency // ------------------------------------------- @@ -6800,7 +6940,7 @@ int AArch64TargetLowering::getScalingFactorCost(const AddrMode &AM, // ------------------------------------------- // Rt, [Xn, Xm, lsl #imm] | Rn: 4 Rm: 5 // Rt, [Xn, Wm, <extend> #imm] | - if (isLegalAddressingMode(AM, Ty)) + if (isLegalAddressingMode(AM, Ty, AS)) // Scale represents reg2 * scale, thus account for 1 if // it is not equal to 0 or 1. return AM.Scale != 0 && AM.Scale != 1; @@ -9120,3 +9260,8 @@ bool AArch64TargetLowering::functionArgumentNeedsConsecutiveRegisters( Type *Ty, CallingConv::ID CallConv, bool isVarArg) const { return Ty->isArrayTy(); } + +bool AArch64TargetLowering::shouldNormalizeToSelectSequence(LLVMContext &, + EVT) const { + return false; +} |
