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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153901 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 0894607..a71cf82 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -5342,7 +5342,8 @@
// 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 @@
// 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 @@
// 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);