From a56f2822d0d3ff3ac1d289a8b7834d7f90415f6d Mon Sep 17 00:00:00 2001 From: Simon Pilgrim Date: Tue, 19 Mar 2019 16:24:55 +0000 Subject: [SelectionDAG] Handle unary SelectPatternFlavor for ABS case in SelectionDAGBuilder::visitSelect These changes are related to PR37743 and include: SelectionDAGBuilder::visitSelect handles the unary SelectPatternFlavor::SPF_ABS case to build ABS node. Delete the redundant recognizer of the integer ABS pattern from the DAGCombiner. Add promoting the integer ABS node in the LegalizeIntegerType. Expand-based legalization of integer result for the ABS nodes. Expand-based legalization of ABS vector operations. Add some integer abs testcases for different typesizes for Thumb arch Add the custom ABS expanding and change the SAD pattern recognizer for X86 arch: The i64 result of the ABS is expanded to: tmp = (SRA, Hi, 31) Lo = (UADDO tmp, Lo) Hi = (XOR tmp, (ADDCARRY tmp, hi, Lo:1)) Lo = (XOR tmp, Lo) The "detectZextAbsDiff" function is changed for the recognition of pattern with the ABS node. Given a ABS node, detect the following pattern: (ABS (SUB (ZERO_EXTEND a), (ZERO_EXTEND b))). Change integer abs testcases for codegen with the ABS node support for AArch64. Indicate that the ABS is legal for the i64 type when the NEON is supported. Change the integer abs testcases to show changing of codegen. Add combine and legalization of ABS nodes for Thumb arch. Extend 'matchSelectPattern' to recognize the ABS patterns with ICMP_SGE condition. For discussion, see https://bugs.llvm.org/show_bug.cgi?id=37743 Patch by: @ikulagin (Ivan Kulagin) Differential Revision: https://reviews.llvm.org/D49837 llvm-svn: 356468 --- .../CodeGen/SelectionDAG/SelectionDAGBuilder.cpp | 39 +++++++++++++++++----- 1 file changed, 31 insertions(+), 8 deletions(-) (limited to 'llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp') diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp index fb57f5dd2c5..3aedee8db0b 100644 --- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp @@ -3210,6 +3210,8 @@ void SelectionDAGBuilder::visitSelect(const User &I) { ISD::NodeType OpCode = Cond.getValueType().isVector() ? ISD::VSELECT : ISD::SELECT; + bool IsUnaryAbs = false; + // Min/max matching is only viable if all output VTs are the same. if (is_splat(ValueVTs)) { EVT VT = ValueVTs[0]; @@ -3270,10 +3272,16 @@ void SelectionDAGBuilder::visitSelect(const User &I) { break; } break; + case SPF_ABS: + IsUnaryAbs = true; + Opc = ISD::ABS; + break; + case SPF_NABS: + // TODO: we need to produce sub(0, abs(X)). default: break; } - if (Opc != ISD::DELETED_NODE && + if (!IsUnaryAbs && Opc != ISD::DELETED_NODE && (TLI.isOperationLegalOrCustom(Opc, VT) || (UseScalarMinMax && TLI.isOperationLegalOrCustom(Opc, VT.getScalarType()))) && @@ -3286,15 +3294,30 @@ void SelectionDAGBuilder::visitSelect(const User &I) { RHSVal = getValue(RHS); BaseOps = {}; } + + if (IsUnaryAbs) { + OpCode = Opc; + LHSVal = getValue(LHS); + BaseOps = {}; + } } - for (unsigned i = 0; i != NumValues; ++i) { - SmallVector Ops(BaseOps.begin(), BaseOps.end()); - Ops.push_back(SDValue(LHSVal.getNode(), LHSVal.getResNo() + i)); - Ops.push_back(SDValue(RHSVal.getNode(), RHSVal.getResNo() + i)); - Values[i] = DAG.getNode(OpCode, getCurSDLoc(), - LHSVal.getNode()->getValueType(LHSVal.getResNo()+i), - Ops); + if (IsUnaryAbs) { + for (unsigned i = 0; i != NumValues; ++i) { + Values[i] = + DAG.getNode(OpCode, getCurSDLoc(), + LHSVal.getNode()->getValueType(LHSVal.getResNo() + i), + SDValue(LHSVal.getNode(), LHSVal.getResNo() + i)); + } + } else { + for (unsigned i = 0; i != NumValues; ++i) { + SmallVector Ops(BaseOps.begin(), BaseOps.end()); + Ops.push_back(SDValue(LHSVal.getNode(), LHSVal.getResNo() + i)); + Ops.push_back(SDValue(RHSVal.getNode(), RHSVal.getResNo() + i)); + Values[i] = DAG.getNode( + OpCode, getCurSDLoc(), + LHSVal.getNode()->getValueType(LHSVal.getResNo() + i), Ops); + } } setValue(&I, DAG.getNode(ISD::MERGE_VALUES, getCurSDLoc(), -- cgit v1.2.3