From 852680a8fa4d70055177c7e1d9b0b43f218064d5 Mon Sep 17 00:00:00 2001 From: Dale Johannesen Date: Fri, 5 Sep 2008 21:27:19 +0000 Subject: [PATCH] Add the next limited-precision expansion. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55856 91177308-0d34-0410-b5e6-96231b3b80d8 --- .../SelectionDAG/SelectionDAGBuild.cpp | 45 +++++++++++++++++-- 1 file changed, 42 insertions(+), 3 deletions(-) diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp index c7e2cd5caba..7cd2bb2ea05 100644 --- a/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp +++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp @@ -2798,10 +2798,49 @@ SelectionDAGLowering::visitLog2(CallInst &I) { void SelectionDAGLowering::visitLog10(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::FMUL, MVT::f32, t3, + DAG.getConstantFP(APFloat( + APInt(32, 0x3e9a209a)), MVT::f32)); + SDValue t5 = DAG.getNode(ISD::OR, MVT::i32, operand1, + DAG.getConstant(1065353216, MVT::i32)); + SDValue t6 = DAG.getNode(ISD::AND, MVT::i32, t5, + DAG.getConstant(1073741823, MVT::i32)); + SDValue t7 = DAG.getNode(ISD::BIT_CONVERT, MVT::f32, t6); + SDValue t8 = DAG.getNode(ISD::FP_EXTEND, MVT::f64, t7); + SDValue t9 = DAG.getNode(ISD::FMUL, MVT::f64, t8, + DAG.getConstantFP(APFloat( + APInt(64, 0x3fa863e61d44a337ULL)), MVT::f64)); + SDValue t10 = DAG.getNode(ISD::FSUB, MVT::f64, t9, + DAG.getConstantFP(APFloat( + APInt(64, 0x3fd443f63982ad9aULL)), MVT::f64)); + SDValue t11 = DAG.getNode(ISD::FMUL, MVT::f64, t10, t8); + SDValue t12 = DAG.getNode(ISD::FADD, MVT::f64, t11, + DAG.getConstantFP(APFloat( + APInt(64, 0x3fed5c4641d8bd71ULL)), MVT::f64)); + SDValue t13 = DAG.getNode(ISD::FMUL, MVT::f64, t12, t8); + SDValue t14 = DAG.getNode(ISD::FSUB, MVT::f64, t13, + DAG.getConstantFP(APFloat( + APInt(64, 0x3fe4bef863538c6fULL)), MVT::f64)); + SDValue t15 = DAG.getNode(ISD::FP_ROUND, MVT::f32, t14, + DAG.getConstant(0, MVT::i32)); + result = DAG.getNode(ISD::FADD, MVT::f32, t4, t15); + } else { // No special expansion. - result = DAG.getNode(ISD::FLOG10, - getValue(I.getOperand(1)).getValueType(), - getValue(I.getOperand(1))); + result = DAG.getNode(ISD::FLOG10, + getValue(I.getOperand(1)).getValueType(), + getValue(I.getOperand(1))); + } setValue(&I, result); } -- 2.34.1