diff options
Diffstat (limited to 'llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp index 2885776a306..36c6b90f6e5 100644 --- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp @@ -80,7 +80,7 @@ LimitFPPrecision("limit-float-precision", cl::init(0)); static cl::opt<bool> -EnableFMFInDAG("enable-fmf-dag", cl::init(false), cl::Hidden, +EnableFMFInDAG("enable-fmf-dag", cl::init(true), cl::Hidden, cl::desc("Enable fast-math-flags for DAG nodes")); // Limit the width of DAG chains. This is important in general to prevent @@ -2347,6 +2347,10 @@ void SelectionDAGBuilder::visitFCmp(const User &I) { SDValue Op1 = getValue(I.getOperand(0)); SDValue Op2 = getValue(I.getOperand(1)); ISD::CondCode Condition = getFCmpCondCode(predicate); + + // FIXME: Fcmp instructions have fast-math-flags in IR, so we should use them. + // FIXME: We should propagate the fast-math-flags to the DAG node itself for + // further optimization, but currently FMF is only applicable to binary nodes. if (TM.Options.NoNaNsFPMath) Condition = getFCmpCodeWithoutNaN(Condition); EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(), @@ -3629,6 +3633,8 @@ getF32Constant(SelectionDAG &DAG, unsigned Flt, SDLoc dl) { static SDValue getLimitedPrecisionExp2(SDValue t0, SDLoc dl, SelectionDAG &DAG) { + // TODO: What fast-math-flags should be set on the floating-point nodes? + // IntegerPartOfX = ((int32_t)(t0); SDValue IntegerPartOfX = DAG.getNode(ISD::FP_TO_SINT, dl, MVT::i32, t0); @@ -3727,6 +3733,8 @@ static SDValue expandExp(SDLoc dl, SDValue Op, SelectionDAG &DAG, // // #define LOG2OFe 1.4426950f // t0 = Op * LOG2OFe + + // TODO: What fast-math-flags should be set here? SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, Op, getF32Constant(DAG, 0x3fb8aa3b, dl)); return getLimitedPrecisionExp2(t0, dl, DAG); @@ -3740,6 +3748,9 @@ static SDValue expandExp(SDLoc dl, SDValue Op, SelectionDAG &DAG, /// limited-precision mode. static SDValue expandLog(SDLoc dl, SDValue Op, SelectionDAG &DAG, const TargetLowering &TLI) { + + // TODO: What fast-math-flags should be set on the floating-point nodes? + if (Op.getValueType() == MVT::f32 && LimitFloatPrecision > 0 && LimitFloatPrecision <= 18) { SDValue Op1 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, Op); @@ -3836,6 +3847,9 @@ static SDValue expandLog(SDLoc dl, SDValue Op, SelectionDAG &DAG, /// limited-precision mode. static SDValue expandLog2(SDLoc dl, SDValue Op, SelectionDAG &DAG, const TargetLowering &TLI) { + + // TODO: What fast-math-flags should be set on the floating-point nodes? + if (Op.getValueType() == MVT::f32 && LimitFloatPrecision > 0 && LimitFloatPrecision <= 18) { SDValue Op1 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, Op); @@ -3931,6 +3945,9 @@ static SDValue expandLog2(SDLoc dl, SDValue Op, SelectionDAG &DAG, /// limited-precision mode. static SDValue expandLog10(SDLoc dl, SDValue Op, SelectionDAG &DAG, const TargetLowering &TLI) { + + // TODO: What fast-math-flags should be set on the floating-point nodes? + if (Op.getValueType() == MVT::f32 && LimitFloatPrecision > 0 && LimitFloatPrecision <= 18) { SDValue Op1 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, Op); @@ -4040,6 +4057,7 @@ static SDValue expandPow(SDLoc dl, SDValue LHS, SDValue RHS, } } + // TODO: What fast-math-flags should be set on the FMUL node? if (IsExp10) { // Put the exponent in the right bit position for later addition to the // final result: @@ -4083,6 +4101,8 @@ static SDValue ExpandPowI(SDLoc DL, SDValue LHS, SDValue RHS, // the benefit of being both really simple and much better than a libcall. SDValue Res; // Logically starts equal to 1.0 SDValue CurSquare = LHS; + // TODO: Intrinsics should have fast-math-flags that propagate to these + // nodes. while (Val) { if (Val & 1) { if (Res.getNode()) @@ -4736,6 +4756,7 @@ SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I, unsigned Intrinsic) { getValue(I.getArgOperand(1)), getValue(I.getArgOperand(2)))); } else { + // TODO: Intrinsic calls should have fast-math-flags. SDValue Mul = DAG.getNode(ISD::FMUL, sdl, getValue(I.getArgOperand(0)).getValueType(), getValue(I.getArgOperand(0)), |
