From 1d5ae1026e831016fc29fd927877c86af904481f Mon Sep 17 00:00:00 2001
From: Dimitry Andric <dim@FreeBSD.org>
Date: Wed, 23 Oct 2019 17:51:42 +0000
Subject: Vendor import of stripped llvm trunk r375505, the last commit before
 the upstream Subversion repository was made read-only, and the LLVM project
 migrated to GitHub:

https://llvm.org/svn/llvm-project/llvm/trunk@375505
---
 lib/Transforms/Utils/FlattenCFG.cpp | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

(limited to 'lib/Transforms/Utils/FlattenCFG.cpp')

diff --git a/lib/Transforms/Utils/FlattenCFG.cpp b/lib/Transforms/Utils/FlattenCFG.cpp
index 0c52e6f3703b..893f23eb6048 100644
--- a/lib/Transforms/Utils/FlattenCFG.cpp
+++ b/lib/Transforms/Utils/FlattenCFG.cpp
@@ -67,7 +67,7 @@ public:
 /// Before:
 ///   ......
 ///   %cmp10 = fcmp une float %tmp1, %tmp2
-///   br i1 %cmp1, label %if.then, label %lor.rhs
+///   br i1 %cmp10, label %if.then, label %lor.rhs
 ///
 /// lor.rhs:
 ///   ......
@@ -251,8 +251,8 @@ bool FlattenCFGOpt::FlattenParallelAndOr(BasicBlock *BB, IRBuilder<> &Builder) {
     bool EverChanged = false;
     for (; CurrBlock != FirstCondBlock;
          CurrBlock = CurrBlock->getSinglePredecessor()) {
-      BranchInst *BI = dyn_cast<BranchInst>(CurrBlock->getTerminator());
-      CmpInst *CI = dyn_cast<CmpInst>(BI->getCondition());
+      auto *BI = cast<BranchInst>(CurrBlock->getTerminator());
+      auto *CI = dyn_cast<CmpInst>(BI->getCondition());
       if (!CI)
         continue;
 
@@ -278,7 +278,7 @@ bool FlattenCFGOpt::FlattenParallelAndOr(BasicBlock *BB, IRBuilder<> &Builder) {
 
   // Do the transformation.
   BasicBlock *CB;
-  BranchInst *PBI = dyn_cast<BranchInst>(FirstCondBlock->getTerminator());
+  BranchInst *PBI = cast<BranchInst>(FirstCondBlock->getTerminator());
   bool Iteration = true;
   IRBuilder<>::InsertPointGuard Guard(Builder);
   Value *PC = PBI->getCondition();
@@ -444,7 +444,7 @@ bool FlattenCFGOpt::MergeIfRegion(BasicBlock *BB, IRBuilder<> &Builder) {
   FirstEntryBlock->getInstList().pop_back();
   FirstEntryBlock->getInstList()
       .splice(FirstEntryBlock->end(), SecondEntryBlock->getInstList());
-  BranchInst *PBI = dyn_cast<BranchInst>(FirstEntryBlock->getTerminator());
+  BranchInst *PBI = cast<BranchInst>(FirstEntryBlock->getTerminator());
   Value *CC = PBI->getCondition();
   BasicBlock *SaveInsertBB = Builder.GetInsertBlock();
   BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint();
@@ -453,6 +453,16 @@ bool FlattenCFGOpt::MergeIfRegion(BasicBlock *BB, IRBuilder<> &Builder) {
   PBI->replaceUsesOfWith(CC, NC);
   Builder.SetInsertPoint(SaveInsertBB, SaveInsertPt);
 
+  // Handle PHI node to replace its predecessors to FirstEntryBlock.
+  for (BasicBlock *Succ : successors(PBI)) {
+    for (PHINode &Phi : Succ->phis()) {
+      for (unsigned i = 0, e = Phi.getNumIncomingValues(); i != e; ++i) {
+        if (Phi.getIncomingBlock(i) == SecondEntryBlock)
+          Phi.setIncomingBlock(i, FirstEntryBlock);
+      }
+    }
+  }
+
   // Remove IfTrue1
   if (IfTrue1 != FirstEntryBlock) {
     IfTrue1->dropAllReferences();
-- 
cgit v1.2.3