[LoopVectorize] Use ReplaceInstWithInst() helper where appropriate.

This is mostly an NFC, which increases code readability (instead of
saving old terminator, generating new one in front of old, and deleting
old, we just call a function). However, it would additionaly copy
the debug location from old instruction to replacement, which
would help PR23837.

llvm-svn: 241197

1 files changed, 15 insertions, 22 deletions

diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index eff7c03c7f7..5ba14174ac7 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -2415,9 +2415,8 @@ void InnerLoopVectorizer::scalarizeInstruction(Instruction *Instr, bool IfPredic
          LoopVectorBody.push_back(NewIfBlock);
          VectorLp->addBasicBlockToLoop(NewIfBlock, *LI);
          Builder.SetInsertPoint(InsertPt);
-         Instruction *OldBr = IfBlock->getTerminator();
-         BranchInst::Create(CondBlock, NewIfBlock, Cmp, OldBr);
-         OldBr->eraseFromParent();
+         ReplaceInstWithInst(IfBlock->getTerminator(),
+                             BranchInst::Create(CondBlock, NewIfBlock, Cmp));
          IfBlock = NewIfBlock;
       }
     }
@@ -2660,9 +2659,9 @@ void InnerLoopVectorizer::createEmptyLoop() {
     if (ParentLoop)
       ParentLoop->addBasicBlockToLoop(CheckBlock, *LI);
     LoopBypassBlocks.push_back(CheckBlock);
-    Instruction *OldTerm = LastBypassBlock->getTerminator();
-    BranchInst::Create(ScalarPH, CheckBlock, CheckBCOverflow, OldTerm);
-    OldTerm->eraseFromParent();
+    ReplaceInstWithInst(
+        LastBypassBlock->getTerminator(),
+        BranchInst::Create(ScalarPH, CheckBlock, CheckBCOverflow));
     LastBypassBlock = CheckBlock;
   }
 
@@ -2684,9 +2683,8 @@ void InnerLoopVectorizer::createEmptyLoop() {
 
     // Replace the branch into the memory check block with a conditional branch
     // for the "few elements case".
-    Instruction *OldTerm = LastBypassBlock->getTerminator();
-    BranchInst::Create(MiddleBlock, CheckBlock, Cmp, OldTerm);
-    OldTerm->eraseFromParent();
+    ReplaceInstWithInst(LastBypassBlock->getTerminator(),
+                        BranchInst::Create(MiddleBlock, CheckBlock, Cmp));
 
     Cmp = StrideCheck;
     LastBypassBlock = CheckBlock;
@@ -2709,17 +2707,15 @@ void InnerLoopVectorizer::createEmptyLoop() {
 
     // Replace the branch into the memory check block with a conditional branch
     // for the "few elements case".
-    Instruction *OldTerm = LastBypassBlock->getTerminator();
-    BranchInst::Create(MiddleBlock, CheckBlock, Cmp, OldTerm);
-    OldTerm->eraseFromParent();
+    ReplaceInstWithInst(LastBypassBlock->getTerminator(),
+                        BranchInst::Create(MiddleBlock, CheckBlock, Cmp));
 
     Cmp = MemRuntimeCheck;
     LastBypassBlock = CheckBlock;
   }
 
-  LastBypassBlock->getTerminator()->eraseFromParent();
-  BranchInst::Create(MiddleBlock, VectorPH, Cmp,
-                     LastBypassBlock);
+  ReplaceInstWithInst(LastBypassBlock->getTerminator(),
+                      BranchInst::Create(MiddleBlock, VectorPH, Cmp));
 
   // We are going to resume the execution of the scalar loop.
   // Go over all of the induction variables that we found and fix the
@@ -2856,10 +2852,8 @@ void InnerLoopVectorizer::createEmptyLoop() {
   Value *CmpN = CmpInst::Create(Instruction::ICmp, CmpInst::ICMP_EQ, IdxEnd,
                                 ResumeIndex, "cmp.n",
                                 MiddleBlock->getTerminator());
-
-  BranchInst::Create(ExitBlock, ScalarPH, CmpN, MiddleBlock->getTerminator());
-  // Remove the old terminator.
-  MiddleBlock->getTerminator()->eraseFromParent();
+  ReplaceInstWithInst(MiddleBlock->getTerminator(),
+                      BranchInst::Create(ExitBlock, ScalarPH, CmpN));
 
   // Create i+1 and fill the PHINode.
   Value *NextIdx = Builder.CreateAdd(Induction, Step, "index.next");
@@ -5513,9 +5507,8 @@ void InnerLoopUnroller::scalarizeInstruction(Instruction *Instr,
         LoopVectorBody.push_back(NewIfBlock);
         VectorLp->addBasicBlockToLoop(NewIfBlock, *LI);
         Builder.SetInsertPoint(InsertPt);
-        Instruction *OldBr = IfBlock->getTerminator();
-        BranchInst::Create(CondBlock, NewIfBlock, Cmp, OldBr);
-        OldBr->eraseFromParent();
+        ReplaceInstWithInst(IfBlock->getTerminator(),
+                            BranchInst::Create(CondBlock, NewIfBlock, Cmp));
         IfBlock = NewIfBlock;
       }
   }