diff options
| author | Dale Johannesen <dalej@apple.com> | 2008-09-05 23:49:37 +0000 |
|---|---|---|
| committer | Dale Johannesen <dalej@apple.com> | 2008-09-05 23:49:37 +0000 |
| commit | 853244f8a6d314a9d90824c3d13e8cd368fb88ed (patch) | |
| tree | 23431e48309a814541bd6e99507303f105f524ff | |
| parent | 6e6074508c2f781c3e52dfe0e301cb1c7f395a91 (diff) | |
Next limited float precision expansion (log2 12 bits)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55866 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp | 46 |
1 files changed, 43 insertions, 3 deletions
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp index 7cd2bb2ea0..63bbfe0851 100644 --- a/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp +++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp @@ -2785,10 +2785,50 @@ SelectionDAGLowering::visitLog(CallInst &I) { void SelectionDAGLowering::visitLog2(CallInst &I) { SDValue result; + if (getValue(I.getOperand(1)).getValueType() == MVT::f32 && + LimitFloatPrecision>0 && LimitFloatPrecision<=12) { + SDValue operand = getValue(I.getOperand(1)); + SDValue operand1 = DAG.getNode(ISD::BIT_CONVERT, MVT::i32, operand); + SDValue t0 = DAG.getNode(ISD::SRL, MVT::i32, operand1, + DAG.getConstant(23, MVT::i32)); + SDValue t1 = DAG.getNode(ISD::AND, MVT::i32, t0, + DAG.getConstant(255, MVT::i32)); + SDValue t2 = DAG.getNode(ISD::SUB, MVT::i32, t1, + DAG.getConstant(127, MVT::i32)); + SDValue t3 = DAG.getNode(ISD::UINT_TO_FP, MVT::f32, t2); + SDValue t4 = DAG.getNode(ISD::OR, MVT::i32, operand1, + DAG.getConstant(1065353216, MVT::i32)); + SDValue t5 = DAG.getNode(ISD::AND, MVT::i32, t4, + DAG.getConstant(1073741823, MVT::i32)); + SDValue t6 = DAG.getNode(ISD::BIT_CONVERT, MVT::f32, t5); + SDValue t7 = DAG.getNode(ISD::FP_EXTEND, MVT::f64, t6); + SDValue t8 = DAG.getNode(ISD::FMUL, MVT::f64, t7, + DAG.getConstantFP(APFloat( + APInt(64, 0xbfb4e4c5b6dfced3ULL)), MVT::f64)); + SDValue t9 = DAG.getNode(ISD::FADD, MVT::f64, t8, + DAG.getConstantFP(APFloat( + APInt(64, 0x3fe4a5015b0db188ULL)), MVT::f64)); + SDValue t10 = DAG.getNode(ISD::FMUL, MVT::f64, t9, t7); + SDValue t11 = DAG.getNode(ISD::FSUB, MVT::f64, t10, + DAG.getConstantFP(APFloat( + APInt(64, 0x4000f724658ffcb8ULL)), MVT::f64)); + SDValue t12 = DAG.getNode(ISD::FMUL, MVT::f64, t11, t7); + SDValue t13 = DAG.getNode(ISD::FADD, MVT::f64, t12, + DAG.getConstantFP(APFloat( + APInt(64, 0x401047c5d1dbd553ULL)), MVT::f64)); + SDValue t14 = DAG.getNode(ISD::FMUL, MVT::f64, t13, t7); + SDValue t15 = DAG.getNode(ISD::FSUB, MVT::f64, t14, + DAG.getConstantFP(APFloat( + APInt(64, 0x40041a537b273db2ULL)), MVT::f64)); + SDValue t16 = DAG.getNode(ISD::FP_ROUND, MVT::f32, t15, + DAG.getConstant(0, MVT::i32)); + result = DAG.getNode(ISD::FADD, MVT::f32, t3, t16); + } else { // No special expansion. - result = DAG.getNode(ISD::FLOG2, - getValue(I.getOperand(1)).getValueType(), - getValue(I.getOperand(1))); + result = DAG.getNode(ISD::FLOG2, + getValue(I.getOperand(1)).getValueType(), + getValue(I.getOperand(1))); + } setValue(&I, result); } |