[clang] [llvm] [LoopUnroll] Add flag to enforce loop unroll pragma regardless of expensive trip count (PR #180961)

[Adel Ejjeh via cfe-commits]

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@@ -1102,7 +1110,8 @@ bool llvm::computeUnrollCount(
   }
   if (UP.Count == 0)
     UP.Count = UP.DefaultUnrollRuntimeCount;
-
+  if (PragmaEnableUnroll && ForcePragmaUnroll)
+    UP.AllowExpensiveTripCount = true;
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adelejjeh wrote:

Just wanted to add, the intent of moving towards what you are suggesting is pending more testing to make sure we fully understand the ramifications on different workloads if we change the default behavior of the compiler.

https://github.com/llvm/llvm-project/pull/180961