[llvm] [LoopInterchange] Ignore the cost-model, force interchange if legal (PR #148858)

[Sjoerd Meijer via llvm-commits]

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@@ -1311,6 +1320,11 @@ bool LoopInterchangeProfitability::isProfitable(
       shouldInterchange =
           isProfitableForVectorization(InnerLoopId, OuterLoopId, DepMatrix);
       break;
+    case RuleTy::Ignore:
+      LLVM_DEBUG(dbgs() << "Interchange profitability: option 'ignore' has no "
+                           "effect in combination with other options\n";
+                 dbgs() << "To force interchange, only use 'ignore'");
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sjoerdmeijer wrote:

Done, I have added the check to see if ignore appears in a list to function noDuplicatesAndIgnore. I think this is fine now. 

https://github.com/llvm/llvm-project/pull/148858