[llvm] [SimplifyCFG] Fold pairs of entries in multiple-entry phi (PR #73674)

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git-clang-format --diff 21361bb8605fd26a06312d80b9fb20a8b41c58ed e8f00600aa476ca9f498a875964bfd20c35396d5 -- llvm/include/llvm/Transforms/Utils/BasicBlockUtils.h llvm/lib/Transforms/Utils/BasicBlockUtils.cpp llvm/lib/Transforms/Utils/FlattenCFG.cpp llvm/lib/Transforms/Utils/SimplifyCFG.cpp
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View the diff from clang-format here.
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``````````diff
diff --git a/llvm/include/llvm/Transforms/Utils/BasicBlockUtils.h b/llvm/include/llvm/Transforms/Utils/BasicBlockUtils.h
index 998acbe9ab..588028cdff 100644
--- a/llvm/include/llvm/Transforms/Utils/BasicBlockUtils.h
+++ b/llvm/include/llvm/Transforms/Utils/BasicBlockUtils.h
@@ -596,7 +596,7 @@ void SplitBlockAndInsertForEachLane(
 /// This does no checking to see if the true/false blocks have large or unsavory
 /// instructions in them.
 BranchInst *GetIfConditionFromMergePoint(BasicBlock *BB, BasicBlock *&IfTrue,
-                           BasicBlock *&IfFalse);
+                                         BasicBlock *&IfFalse);
 
 /// Check whether BB is the dominant point of a if-region.
 /// If so, return the merge point of the if-region. Also, return by references
@@ -606,7 +606,8 @@ BranchInst *GetIfConditionFromMergePoint(BasicBlock *BB, BasicBlock *&IfTrue,
 /// This does no checking to see if the true/false blocks have large or unsavory
 /// instructions in them.
 ///
-/// NOTE: we assume that the terminator of DomBB is a conditional branch instruction. 
+/// NOTE: we assume that the terminator of DomBB is a conditional branch
+/// instruction.
 BasicBlock *GetIfConditionFromDom(BasicBlock *DomBB, BasicBlock *&IfTrue,
                                   BasicBlock *&IfFalse);
 
diff --git a/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp b/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
index d43a5f7284..f1ceab4d55 100644
--- a/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
+++ b/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
@@ -1727,8 +1727,9 @@ void llvm::SplitBlockAndInsertForEachLane(
   }
 }
 
-BranchInst *llvm::GetIfConditionFromMergePoint(BasicBlock *BB, BasicBlock *&IfTrue,
-                                 BasicBlock *&IfFalse) {
+BranchInst *llvm::GetIfConditionFromMergePoint(BasicBlock *BB,
+                                               BasicBlock *&IfTrue,
+                                               BasicBlock *&IfFalse) {
   PHINode *SomePHI = dyn_cast<PHINode>(BB->begin());
   BasicBlock *Pred1 = nullptr;
   BasicBlock *Pred2 = nullptr;
@@ -1821,7 +1822,7 @@ BranchInst *llvm::GetIfConditionFromMergePoint(BasicBlock *BB, BasicBlock *&IfTr
 
 BasicBlock *llvm::GetIfConditionFromDom(BasicBlock *DomBB, BasicBlock *&IfTrue,
                                         BasicBlock *&IfFalse) {
-  BranchInst* BI = cast<BranchInst>(DomBB->getTerminator());
+  BranchInst *BI = cast<BranchInst>(DomBB->getTerminator());
   BasicBlock *Succ1 = BI->getSuccessor(0);
   BasicBlock *Succ2 = BI->getSuccessor(1);
 
diff --git a/llvm/lib/Transforms/Utils/FlattenCFG.cpp b/llvm/lib/Transforms/Utils/FlattenCFG.cpp
index 4480202bae..08fbcef5cd 100644
--- a/llvm/lib/Transforms/Utils/FlattenCFG.cpp
+++ b/llvm/lib/Transforms/Utils/FlattenCFG.cpp
@@ -420,7 +420,8 @@ bool FlattenCFGOpt::MergeIfRegion(BasicBlock *BB, IRBuilder<> &Builder) {
     return false;
 
   BasicBlock *IfTrue1, *IfFalse1;
-  BranchInst *DomBI1 = GetIfConditionFromMergePoint(SecondEntryBlock, IfTrue1, IfFalse1);
+  BranchInst *DomBI1 =
+      GetIfConditionFromMergePoint(SecondEntryBlock, IfTrue1, IfFalse1);
   if (!DomBI1)
     return false;
   Instruction *CInst1 = dyn_cast<Instruction>(DomBI1->getCondition());

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https://github.com/llvm/llvm-project/pull/73674