From 98f2c0c384e2aa39578cd8e9c96fe3c45e4b68d2 Mon Sep 17 00:00:00 2001 From: Owen Anderson Date: Mon, 2 Apr 2012 22:10:29 +0000 Subject: Add predicates for checking whether targets have free FNEG and FABS operations, and prevent the DAGCombiner from turning them into bitwise operations if they do. llvm-svn: 153901 --- llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'llvm/lib/CodeGen') diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 08946070b44..a71cf82cd58 100644 --- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -5342,7 +5342,8 @@ SDValue DAGCombiner::visitBITCAST(SDNode *N) { // fold (bitconvert (fneg x)) -> (xor (bitconvert x), signbit) // fold (bitconvert (fabs x)) -> (and (bitconvert x), (not signbit)) // This often reduces constant pool loads. - if ((N0.getOpcode() == ISD::FNEG || N0.getOpcode() == ISD::FABS) && + if (((N0.getOpcode() == ISD::FNEG && !TLI.isFNegFree(VT)) || + (N0.getOpcode() == ISD::FABS && !TLI.isFAbsFree(VT))) && N0.getNode()->hasOneUse() && VT.isInteger() && !VT.isVector()) { SDValue NewConv = DAG.getNode(ISD::BITCAST, N0.getDebugLoc(), VT, N0.getOperand(0)); @@ -5993,7 +5994,7 @@ SDValue DAGCombiner::visitFNEG(SDNode *N) { // Transform fneg(bitconvert(x)) -> bitconvert(x^sign) to avoid loading // constant pool values. - if (N0.getOpcode() == ISD::BITCAST && + if (!TLI.isFNegFree(VT) && N0.getOpcode() == ISD::BITCAST && !VT.isVector() && N0.getNode()->hasOneUse() && N0.getOperand(0).getValueType().isInteger()) { @@ -6029,7 +6030,8 @@ SDValue DAGCombiner::visitFABS(SDNode *N) { // Transform fabs(bitconvert(x)) -> bitconvert(x&~sign) to avoid loading // constant pool values. - if (N0.getOpcode() == ISD::BITCAST && N0.getNode()->hasOneUse() && + if (!TLI.isFAbsFree(VT) && + N0.getOpcode() == ISD::BITCAST && N0.getNode()->hasOneUse() && N0.getOperand(0).getValueType().isInteger() && !N0.getOperand(0).getValueType().isVector()) { SDValue Int = N0.getOperand(0); -- cgit v1.2.3