[llvm] [VPlan] Delay adding canonical IV increment. (PR #82270)

[Florian Hahn via llvm-commits]

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@@ -1618,30 +1578,26 @@ bool VPlanTransforms::tryAddExplicitVectorLength(
   auto *VPEVL = Builder.createNaryOp(VPInstruction::ExplicitVectorLength, AVL,
                                      DebugLoc());
 
-  auto *CanonicalIVIncrement =
-      cast<VPInstruction>(CanonicalIVPHI->getBackedgeValue());
   VPSingleDefRecipe *OpVPEVL = VPEVL;
+  VPRecipeBase *LatchTerm = Latch->getTerminator();
   if (unsigned IVSize = CanonicalIVPHI->getScalarType()->getScalarSizeInBits();
       IVSize != 32) {
     OpVPEVL = new VPScalarCastRecipe(IVSize < 32 ? Instruction::Trunc
                                                  : Instruction::ZExt,
                                      OpVPEVL, CanonicalIVPHI->getScalarType());
-    OpVPEVL->insertBefore(CanonicalIVIncrement);
+    OpVPEVL->insertBefore(LatchTerm);
   }
   auto *NextEVLIV =
-      new VPInstruction(Instruction::Add, {OpVPEVL, EVLPhi},
-                        {CanonicalIVIncrement->hasNoUnsignedWrap(),
-                         CanonicalIVIncrement->hasNoSignedWrap()},
-                        CanonicalIVIncrement->getDebugLoc(), "index.evl.next");
-  NextEVLIV->insertBefore(CanonicalIVIncrement);
+      new VPInstruction(Instruction::Add, {OpVPEVL, EVLPhi}, {false, false},
+                        CanonicalIVPHI->getDebugLoc(), "index.evl.next");
+  NextEVLIV->insertBefore(LatchTerm);
   EVLPhi->addOperand(NextEVLIV);
 
   transformRecipestoEVLRecipes(Plan, *VPEVL);
 
   // Replace all uses of VPCanonicalIVPHIRecipe by
-  // VPEVLBasedIVPHIRecipe except for the canonical IV increment.
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fhahn wrote:

Yes updated, thanks

https://github.com/llvm/llvm-project/pull/82270