[llvm] [LoopUnroll] Use branch probability in multi-exit loop unrolling (PR #164799)

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git-clang-format --diff origin/main HEAD --extensions cpp -- llvm/lib/Transforms/Utils/LoopUnrollRuntime.cpp --diff_from_common_commit
``````````

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``````````diff
diff --git a/llvm/lib/Transforms/Utils/LoopUnrollRuntime.cpp b/llvm/lib/Transforms/Utils/LoopUnrollRuntime.cpp
index 520fd741e..c3ef587fd 100644
--- a/llvm/lib/Transforms/Utils/LoopUnrollRuntime.cpp
+++ b/llvm/lib/Transforms/Utils/LoopUnrollRuntime.cpp
@@ -527,7 +527,7 @@ computeBranchProbabilityUsingMetadata(BasicBlock *Src, BasicBlock *Dst) {
 /// Returns true if we can profitably unroll the multi-exit loop L. Currently,
 /// we return true only if UnrollRuntimeMultiExit is set to true.
 static bool canProfitablyRuntimeUnrollMultiExitLoop(
-    Loop *L, const TargetTransformInfo *TTI, 
+    Loop *L, const TargetTransformInfo *TTI,
     SmallVectorImpl<BasicBlock *> &OtherExits, BasicBlock *LatchExit,
     bool UseEpilogRemainder) {
 
@@ -573,8 +573,8 @@ static bool canProfitablyRuntimeUnrollMultiExitLoop(
       return UnrollRuntimeOtherExitPredictable || *BranchProb < Threshold;
     }
   }
-  
-  // We know that deoptimize blocks are rarely taken, which also implies the 
+
+  // We know that deoptimize blocks are rarely taken, which also implies the
   // branch leading to the deoptimize block is highly predictable. When
   // UnrollRuntimeOtherExitPredictable is specified, we assume the other exit
   // branch is predictable even if it has no deoptimize call.
@@ -720,9 +720,8 @@ bool llvm::UnrollRuntimeLoopRemainder(
       // Otherwise perform multi-exit unrolling, if either the target indicates
       // it is profitable or the general profitability heuristics apply.
       if (!RuntimeUnrollMultiExit &&
-          !canProfitablyRuntimeUnrollMultiExitLoop(L, TTI, OtherExits,
-                                                   LatchExit,
-                                                   UseEpilogRemainder)) {
+          !canProfitablyRuntimeUnrollMultiExitLoop(
+              L, TTI, OtherExits, LatchExit, UseEpilogRemainder)) {
         LLVM_DEBUG(dbgs() << "Multiple exit/exiting blocks in loop and "
                              "multi-exit unrolling not enabled!\n");
         return false;

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https://github.com/llvm/llvm-project/pull/164799