[llvm] 7068c84 - [DAG] visitREM - use isAllOnesOrAllOnesSplat instead of isConstOrConstSplat

[Simon Pilgrim via llvm-commits]

Author: Simon Pilgrim
Date: 2022-07-05T16:44:31+01:00
New Revision: 7068c843d25447e5fc9b1c2a1f7d91275642cc24

URL: https://github.com/llvm/llvm-project/commit/7068c843d25447e5fc9b1c2a1f7d91275642cc24
DIFF: https://github.com/llvm/llvm-project/commit/7068c843d25447e5fc9b1c2a1f7d91275642cc24.diff

LOG: [DAG] visitREM - use isAllOnesOrAllOnesSplat instead of isConstOrConstSplat

We were only using the N1C scalar/splat value once, so for clarity use isAllOnesOrAllOnesSplat instead if we actually need it.

Added: 
    

Modified: 
    llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

Removed: 
    


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diff  --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index dbb81ab65ebb..07b237f7436f 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -4552,13 +4552,12 @@ SDValue DAGCombiner::visitREM(SDNode *N) {
   SDLoc DL(N);
 
   // fold (rem c1, c2) -> c1%c2
-  ConstantSDNode *N1C = isConstOrConstSplat(N1);
   if (SDValue C = DAG.FoldConstantArithmetic(Opcode, DL, VT, {N0, N1}))
     return C;
 
   // fold (urem X, -1) -> select(FX == -1, 0, FX)
   // Freeze the numerator to avoid a miscompile with an undefined value.
-  if (!isSigned && N1C && N1C->isAllOnes()) {
+  if (!isSigned && llvm::isAllOnesOrAllOnesSplat(N1, /*AllowUndefs*/ false)) {
     SDValue F0 = DAG.getFreeze(N0);
     SDValue EqualsNeg1 = DAG.getSetCC(DL, CCVT, F0, N1, ISD::SETEQ);
     return DAG.getSelect(DL, VT, EqualsNeg1, DAG.getConstant(0, DL, VT), F0);