Revert "[LV] Strip unmaintainable MinBWs assert (llvm#136858)"

This reverts commit c4f723a.

Author: jmmartinez

llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp

@@ -1632,6 +1632,11 @@ static void licm(VPlan &Plan) {
 
 void VPlanTransforms::truncateToMinimalBitwidths(
     VPlan &Plan, const MapVector<Instruction *, uint64_t> &MinBWs) {
+#ifndef NDEBUG
+  // Count the processed recipes and cross check the count later with MinBWs
+  // size, to make sure all entries in MinBWs have been handled.
+  unsigned NumProcessedRecipes = 0;
+#endif
   // Keep track of created truncates, so they can be re-used. Note that we
   // cannot use RAUW after creating a new truncate, as this would could make
   // other uses have different types for their operands, making them invalidly
@@ -1654,12 +1659,38 @@ void VPlanTransforms::truncateToMinimalBitwidths(
       if (!NewResSizeInBits)
         continue;
 
+#ifndef NDEBUG
+      NumProcessedRecipes++;
+#endif
       // If the value wasn't vectorized, we must maintain the original scalar
       // type. Skip those here, after incrementing NumProcessedRecipes. Also
       // skip casts which do not need to be handled explicitly here, as
       // redundant casts will be removed during recipe simplification.
-      if (isa<VPReplicateRecipe, VPWidenCastRecipe>(&R))
+      if (isa<VPReplicateRecipe, VPWidenCastRecipe>(&R)) {
+#ifndef NDEBUG
+        // If any of the operands is a live-in and not used by VPWidenRecipe or
+        // VPWidenSelectRecipe, but in MinBWs, make sure it is counted as
+        // processed as well. When MinBWs is currently constructed, there is no
+        // information about whether recipes are widened or replicated and in
+        // case they are reciplicated the operands are not truncated. Counting
+        // them them here ensures we do not miss any recipes in MinBWs.
+        // TODO: Remove once the analysis is done on VPlan.
+        for (VPValue *Op : R.operands()) {
+          if (!Op->isLiveIn())
+            continue;
+          auto *UV = dyn_cast_or_null<Instruction>(Op->getUnderlyingValue());
+          if (UV && MinBWs.contains(UV) && !ProcessedTruncs.contains(Op) &&
+              none_of(Op->users(),
+                      IsaPred<VPWidenRecipe, VPWidenSelectRecipe>)) {
+            // Add an entry to ProcessedTruncs to avoid counting the same
+            // operand multiple times.
+            ProcessedTruncs[Op] = nullptr;
+            NumProcessedRecipes += 1;
+          }
+        }
+#endif
         continue;
+      }
 
       Type *OldResTy = TypeInfo.inferScalarType(ResultVPV);
       unsigned OldResSizeInBits = OldResTy->getScalarSizeInBits();
@@ -1718,11 +1749,19 @@ void VPlanTransforms::truncateToMinimalBitwidths(
           NewOp->insertBefore(&R);
         } else {
           PH->appendRecipe(NewOp);
+#ifndef NDEBUG
+          auto *OpInst = dyn_cast<Instruction>(Op->getLiveInIRValue());
+          bool IsContained = MinBWs.contains(OpInst);
+          NumProcessedRecipes += IsContained;
+#endif
         }
       }
 
     }
   }
+
+  assert(MinBWs.size() == NumProcessedRecipes &&
+         "some entries in MinBWs haven't been processed");
 }
 
 /// Remove BranchOnCond recipes with true conditions together with removing