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[NFC] TLI query with default(on) behavior wrt DAG combines for fmin/fmax target control 

llvm-svn: 352396
This commit is contained in:
Michael Berg 2019-01-28 18:03:08 +00:00
parent 8f7fc95ab7
commit 685d5f675e
2 changed files with 9 additions and 3 deletions
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2
llvm/include/llvm/CodeGen/TargetLowering.h
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@ -1762,6 +1762,8 @@ public:
Action != TypeSplitVector;
}
virtual bool isProfitableToCombineMinNumMaxNum(EVT VT) const { return true; }
/// Return true if a select of constants (select Cond, C1, C2) should be
/// transformed into simple math ops with the condition value. For example:
/// select Cond, C1, C1-1 --> add (zext Cond), C1-1

10
llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
View File

@ -7206,11 +7206,14 @@ SDValue DAGCombiner::visitCTPOP(SDNode *N) {
// FIXME: This should be checking for no signed zeros on individual operands, as
// well as no nans.
static bool isLegalToCombineMinNumMaxNum(SelectionDAG &DAG, SDValue LHS, SDValue RHS) {
static bool isLegalToCombineMinNumMaxNum(SelectionDAG &DAG, SDValue LHS,
SDValue RHS,
const TargetLowering &TLI) {
const TargetOptions &Options = DAG.getTarget().Options;
EVT VT = LHS.getValueType();
return Options.NoSignedZerosFPMath && VT.isFloatingPoint() &&
TLI.isProfitableToCombineMinNumMaxNum(VT) &&
DAG.isKnownNeverNaN(LHS) && DAG.isKnownNeverNaN(RHS);
}
@ -7480,7 +7483,7 @@ SDValue DAGCombiner::visitSELECT(SDNode *N) {
// select (fcmp gt x, y), x, y -> fmaxnum x, y
//
// This is OK if we don't care what happens if either operand is a NaN.
if (N0.hasOneUse() && isLegalToCombineMinNumMaxNum(DAG, N1, N2))
if (N0.hasOneUse() && isLegalToCombineMinNumMaxNum(DAG, N1, N2, TLI))
if (SDValue FMinMax = combineMinNumMaxNum(DL, VT, Cond0, Cond1, N1, N2,
CC, TLI, DAG))
return FMinMax;
@ -7987,7 +7990,8 @@ SDValue DAGCombiner::visitVSELECT(SDNode *N) {
// NaN.
//
EVT VT = N->getValueType(0);
if (N0.hasOneUse() && isLegalToCombineMinNumMaxNum(DAG, N0.getOperand(0), N0.getOperand(1))) {
if (N0.hasOneUse() && isLegalToCombineMinNumMaxNum(
DAG, N0.getOperand(0), N0.getOperand(1), TLI)) {
ISD::CondCode CC = cast<CondCodeSDNode>(N0.getOperand(2))->get();
if (SDValue FMinMax = combineMinNumMaxNum(
DL, VT, N0.getOperand(0), N0.getOperand(1), N1, N2, CC, TLI, DAG))