diff options
Diffstat (limited to 'lib/Target/X86/X86ISelLowering.cpp')
| -rw-r--r-- | lib/Target/X86/X86ISelLowering.cpp | 35 |
1 files changed, 34 insertions, 1 deletions
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp index 0f99844f24..257757bff0 100644 --- a/lib/Target/X86/X86ISelLowering.cpp +++ b/lib/Target/X86/X86ISelLowering.cpp @@ -8214,6 +8214,30 @@ SDValue X86TargetLowering::EmitCmp(SDValue Op0, SDValue Op1, unsigned X86CC, return DAG.getNode(X86ISD::CMP, dl, MVT::i32, Op0, Op1); } +/// Convert a comparison if required by the subtarget. +SDValue X86TargetLowering::ConvertCmpIfNecessary(SDValue Cmp, + SelectionDAG &DAG) const { + // If the subtarget does not support the FUCOMI instruction, floating-point + // comparisons have to be converted. + if (Subtarget->hasCMov() || + Cmp.getOpcode() != X86ISD::CMP || + !Cmp.getOperand(0).getValueType().isFloatingPoint() || + !Cmp.getOperand(1).getValueType().isFloatingPoint()) + return Cmp; + + // The instruction selector will select an FUCOM instruction instead of + // FUCOMI, which writes the comparison result to FPSW instead of EFLAGS. Hence + // build an SDNode sequence that transfers the result from FPSW into EFLAGS: + // (X86sahf (trunc (srl (X86fp_stsw (trunc (X86cmp ...)), 8)))) + DebugLoc dl = Cmp.getDebugLoc(); + SDValue TruncFPSW = DAG.getNode(ISD::TRUNCATE, dl, MVT::i16, Cmp); + SDValue FNStSW = DAG.getNode(X86ISD::FNSTSW16r, dl, MVT::i16, TruncFPSW); + SDValue Srl = DAG.getNode(ISD::SRL, dl, MVT::i16, FNStSW, + DAG.getConstant(8, MVT::i8)); + SDValue TruncSrl = DAG.getNode(ISD::TRUNCATE, dl, MVT::i8, Srl); + return DAG.getNode(X86ISD::SAHF, dl, MVT::i32, TruncSrl); +} + /// LowerToBT - Result of 'and' is compared against zero. Turn it into a BT node /// if it's possible. SDValue X86TargetLowering::LowerToBT(SDValue And, ISD::CondCode CC, @@ -8335,6 +8359,7 @@ SDValue X86TargetLowering::LowerSETCC(SDValue Op, SelectionDAG &DAG) const { return SDValue(); SDValue EFLAGS = EmitCmp(Op0, Op1, X86CC, DAG); + EFLAGS = ConvertCmpIfNecessary(EFLAGS, DAG); return DAG.getNode(X86ISD::SETCC, dl, MVT::i8, DAG.getConstant(X86CC, MVT::i8), EFLAGS); } @@ -8503,7 +8528,8 @@ SDValue X86TargetLowering::LowerVSETCC(SDValue Op, SelectionDAG &DAG) const { // isX86LogicalCmp - Return true if opcode is a X86 logical comparison. static bool isX86LogicalCmp(SDValue Op) { unsigned Opc = Op.getNode()->getOpcode(); - if (Opc == X86ISD::CMP || Opc == X86ISD::COMI || Opc == X86ISD::UCOMI) + if (Opc == X86ISD::CMP || Opc == X86ISD::COMI || Opc == X86ISD::UCOMI || + Opc == X86ISD::SAHF) return true; if (Op.getResNo() == 1 && (Opc == X86ISD::ADD || @@ -8567,6 +8593,7 @@ SDValue X86TargetLowering::LowerSELECT(SDValue Op, SelectionDAG &DAG) const { SDValue CmpOp0 = Cmp.getOperand(0); Cmp = DAG.getNode(X86ISD::CMP, DL, MVT::i32, CmpOp0, DAG.getConstant(1, CmpOp0.getValueType())); + Cmp = ConvertCmpIfNecessary(Cmp, DAG); SDValue Res = // Res = 0 or -1. DAG.getNode(X86ISD::SETCC_CARRY, DL, Op.getValueType(), @@ -8673,6 +8700,7 @@ SDValue X86TargetLowering::LowerSELECT(SDValue Op, SelectionDAG &DAG) const { // a >= b ? -1 : 0 -> RES = setcc_carry // a >= b ? 0 : -1 -> RES = ~setcc_carry if (Cond.getOpcode() == X86ISD::CMP) { + Cond = ConvertCmpIfNecessary(Cond, DAG); unsigned CondCode = cast<ConstantSDNode>(CC)->getZExtValue(); if ((CondCode == X86::COND_AE || CondCode == X86::COND_B) && @@ -8911,6 +8939,7 @@ SDValue X86TargetLowering::LowerBRCOND(SDValue Op, SelectionDAG &DAG) const { SDValue Cmp = DAG.getNode(X86ISD::CMP, dl, MVT::i32, Cond.getOperand(0), Cond.getOperand(1)); + Cmp = ConvertCmpIfNecessary(Cmp, DAG); CC = DAG.getConstant(X86::COND_NE, MVT::i8); Chain = DAG.getNode(X86ISD::BRCOND, dl, Op.getValueType(), Chain, Dest, CC, Cmp); @@ -8940,6 +8969,7 @@ SDValue X86TargetLowering::LowerBRCOND(SDValue Op, SelectionDAG &DAG) const { SDValue Cmp = DAG.getNode(X86ISD::CMP, dl, MVT::i32, Cond.getOperand(0), Cond.getOperand(1)); + Cmp = ConvertCmpIfNecessary(Cmp, DAG); CC = DAG.getConstant(X86::COND_NE, MVT::i8); Chain = DAG.getNode(X86ISD::BRCOND, dl, Op.getValueType(), Chain, Dest, CC, Cmp); @@ -8973,6 +9003,7 @@ SDValue X86TargetLowering::LowerBRCOND(SDValue Op, SelectionDAG &DAG) const { CC = DAG.getConstant(X86::COND_NE, MVT::i8); Cond = EmitTest(Cond, X86::COND_NE, DAG); } + Cond = ConvertCmpIfNecessary(Cond, DAG); return DAG.getNode(X86ISD::BRCOND, dl, Op.getValueType(), Chain, Dest, CC, Cond); } @@ -11111,6 +11142,7 @@ const char *X86TargetLowering::getTargetNodeName(unsigned Opcode) const { case X86ISD::EH_RETURN: return "X86ISD::EH_RETURN"; case X86ISD::TC_RETURN: return "X86ISD::TC_RETURN"; case X86ISD::FNSTCW16m: return "X86ISD::FNSTCW16m"; + case X86ISD::FNSTSW16r: return "X86ISD::FNSTSW16r"; case X86ISD::LCMPXCHG_DAG: return "X86ISD::LCMPXCHG_DAG"; case X86ISD::LCMPXCHG8_DAG: return "X86ISD::LCMPXCHG8_DAG"; case X86ISD::ATOMADD64_DAG: return "X86ISD::ATOMADD64_DAG"; @@ -11179,6 +11211,7 @@ const char *X86TargetLowering::getTargetNodeName(unsigned Opcode) const { case X86ISD::MEMBARRIER: return "X86ISD::MEMBARRIER"; case X86ISD::SEG_ALLOCA: return "X86ISD::SEG_ALLOCA"; case X86ISD::WIN_FTOL: return "X86ISD::WIN_FTOL"; + case X86ISD::SAHF: return "X86ISD::SAHF"; } } |