[llvm-branch-commits] [llvm] [AArch64] Split large loop dependence masks (PR #153187)

[Sander de Smalen via llvm-branch-commits]

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@@ -5248,49 +5248,94 @@ AArch64TargetLowering::LowerLOOP_DEPENDENCE_MASK(SDValue Op,
                                                  SelectionDAG &DAG) const {
   SDLoc DL(Op);
   uint64_t EltSize = Op.getConstantOperandVal(2);
-  EVT VT = Op.getValueType();
+  EVT FullVT = Op.getValueType();
+  unsigned NumElements = FullVT.getVectorMinNumElements();
+  unsigned NumSplits = 0;
+  EVT EltVT;
   switch (EltSize) {
   case 1:
-    if (VT != MVT::v16i8 && VT != MVT::nxv16i1)
-      return SDValue();
+    EltVT = MVT::i8;
     break;
   case 2:
-    if (VT != MVT::v8i8 && VT != MVT::nxv8i1)
-      return SDValue();
+    if (NumElements >= 16)
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sdesmalen-arm wrote:

Note that this case can quite easily be implemented with some patterns that do the operation returning a wider predicate type (i.e. using a smaller element size), and then extracting the sub-vector.

https://github.com/llvm/llvm-project/pull/153187