Updated VPlanVerifier

Author: Mel-Chen

llvm/lib/Transforms/Vectorize/VPlanVerifier.cpp

@@ -158,22 +158,27 @@ bool VPlanVerifier::verifyEVLRecipe(const VPInstruction &EVL) const {
              .Case<VPScalarCastRecipe>(
                  [&](const VPScalarCastRecipe *S) { return true; })
              .Case<VPInstruction>([&](const VPInstruction *I) {
-               if (I->getOpcode() != Instruction::Add) {
+               switch (I->getOpcode()) {
+               default:
                  errs()
-                     << "EVL is used as an operand in non-VPInstruction::Add\n";
+                     << "EVL is used in VPInstructions that are neither "
+                        "Instruction::Add nor VPInstruction::MergeUntilPivot\n";
                  return false;
+               case Instruction::Add:
+                 if (I->getNumUsers() != 1) {
+                   errs() << "EVL is used in VPInstruction:Add with multiple "
+                             "users\n";
+                   return false;
+                 }
+                 if (!isa<VPEVLBasedIVPHIRecipe>(*I->users().begin())) {
+                   errs() << "Result of VPInstruction::Add with EVL operand is "
+                             "not used by VPEVLBasedIVPHIRecipe\n";
+                   return false;
+                 }
+                 return true;
+               case VPInstruction::MergeUntilPivot:
+                 return VerifyEVLUse(*I, 3);
                }
-               if (I->getNumUsers() != 1) {
-                 errs() << "EVL is used in VPInstruction:Add with multiple "
-                           "users\n";
-                 return false;
-               }
-               if (!isa<VPEVLBasedIVPHIRecipe>(*I->users().begin())) {
-                 errs() << "Result of VPInstruction::Add with EVL operand is "
-                           "not used by VPEVLBasedIVPHIRecipe\n";
-                 return false;
-               }
-               return true;
              })
              .Default([&](const VPUser *U) {
                errs() << "EVL has unexpected user\n";