[llvm-branch-commits] [llvm] 048f184 - [SplitEdge] Add new parameter to SplitEdge to name the newly created basic block

[Sidharth Baveja via llvm-branch-commits]

Author: Sidharth Baveja
Date: 2021-01-07T14:49:23Z
New Revision: 048f184ee488cdc8dadc0b8f9d1def9e6b469a73

URL: https://github.com/llvm/llvm-project/commit/048f184ee488cdc8dadc0b8f9d1def9e6b469a73
DIFF: https://github.com/llvm/llvm-project/commit/048f184ee488cdc8dadc0b8f9d1def9e6b469a73.diff

LOG: [SplitEdge] Add new parameter to SplitEdge to name the newly created basic block

Summary:
Currently SplitEdge does not support passing in parameter which allows you to
name the newly created BasicBlock.

This patch updates the function such that the name of the block can be passed
in, if users of this utility decide to do so.

Reviewed By: Whitney, bmahjour, asbirlea, jamieschmeiser

Differential Revision: https://reviews.llvm.org/D94176

Added: 
    

Modified: 
    llvm/include/llvm/Transforms/Utils/BasicBlockUtils.h
    llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
    llvm/lib/Transforms/Utils/BreakCriticalEdges.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/Transforms/Utils/BasicBlockUtils.h b/llvm/include/llvm/Transforms/Utils/BasicBlockUtils.h
index 64c569de1f58..a1d5ee8fb91b 100644
--- a/llvm/include/llvm/Transforms/Utils/BasicBlockUtils.h
+++ b/llvm/include/llvm/Transforms/Utils/BasicBlockUtils.h
@@ -196,7 +196,8 @@ struct CriticalEdgeSplittingOptions {
 /// to.
 BasicBlock *SplitCriticalEdge(Instruction *TI, unsigned SuccNum,
                               const CriticalEdgeSplittingOptions &Options =
-                                  CriticalEdgeSplittingOptions());
+                                  CriticalEdgeSplittingOptions(),
+                              const Twine &BBName = "");
 
 inline BasicBlock *
 SplitCriticalEdge(BasicBlock *BB, succ_iterator SI,
@@ -248,7 +249,8 @@ unsigned SplitAllCriticalEdges(Function &F,
 /// basic block between \p From and \p To.
 BasicBlock *SplitEdge(BasicBlock *From, BasicBlock *To,
                       DominatorTree *DT = nullptr, LoopInfo *LI = nullptr,
-                      MemorySSAUpdater *MSSAU = nullptr);
+                      MemorySSAUpdater *MSSAU = nullptr,
+                      const Twine &BBName = "");
 
 /// Split the specified block at the specified instruction.
 ///

diff  --git a/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp b/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
index 5b8bc184daca..09888db063e2 100644
--- a/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
+++ b/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
@@ -495,14 +495,16 @@ void llvm::ReplaceInstWithInst(Instruction *From, Instruction *To) {
 }
 
 BasicBlock *llvm::SplitEdge(BasicBlock *BB, BasicBlock *Succ, DominatorTree *DT,
-                            LoopInfo *LI, MemorySSAUpdater *MSSAU) {
+                            LoopInfo *LI, MemorySSAUpdater *MSSAU,
+                            const Twine &BBName) {
   unsigned SuccNum = GetSuccessorNumber(BB, Succ);
 
   // If this is a critical edge, let SplitCriticalEdge do it.
   Instruction *LatchTerm = BB->getTerminator();
   if (SplitCriticalEdge(
           LatchTerm, SuccNum,
-          CriticalEdgeSplittingOptions(DT, LI, MSSAU).setPreserveLCSSA()))
+          CriticalEdgeSplittingOptions(DT, LI, MSSAU).setPreserveLCSSA(),
+          BBName))
     return LatchTerm->getSuccessor(SuccNum);
 
   // If the edge isn't critical, then BB has a single successor or Succ has a
@@ -512,14 +514,15 @@ BasicBlock *llvm::SplitEdge(BasicBlock *BB, BasicBlock *Succ, DominatorTree *DT,
     // block.
     assert(SP == BB && "CFG broken");
     SP = nullptr;
-    return SplitBlock(Succ, &Succ->front(), DT, LI, MSSAU, "", /*Before=*/true);
+    return SplitBlock(Succ, &Succ->front(), DT, LI, MSSAU, BBName,
+                      /*Before=*/true);
   }
 
   // Otherwise, if BB has a single successor, split it at the bottom of the
   // block.
   assert(BB->getTerminator()->getNumSuccessors() == 1 &&
          "Should have a single succ!");
-  return SplitBlock(BB, BB->getTerminator(), DT, LI, MSSAU);
+  return SplitBlock(BB, BB->getTerminator(), DT, LI, MSSAU, BBName);
 }
 
 unsigned

diff  --git a/llvm/lib/Transforms/Utils/BreakCriticalEdges.cpp b/llvm/lib/Transforms/Utils/BreakCriticalEdges.cpp
index e42f469ad32c..c9f08e5a9ed5 100644
--- a/llvm/lib/Transforms/Utils/BreakCriticalEdges.cpp
+++ b/llvm/lib/Transforms/Utils/BreakCriticalEdges.cpp
@@ -134,9 +134,9 @@ static void createPHIsForSplitLoopExit(ArrayRef<BasicBlock *> Preds,
   }
 }
 
-BasicBlock *
-llvm::SplitCriticalEdge(Instruction *TI, unsigned SuccNum,
-                        const CriticalEdgeSplittingOptions &Options) {
+BasicBlock *llvm::SplitCriticalEdge(Instruction *TI, unsigned SuccNum,
+                                    const CriticalEdgeSplittingOptions &Options,
+                                    const Twine &BBName) {
   if (!isCriticalEdge(TI, SuccNum, Options.MergeIdenticalEdges))
     return nullptr;
 
@@ -196,8 +196,13 @@ llvm::SplitCriticalEdge(Instruction *TI, unsigned SuccNum,
   }
 
   // Create a new basic block, linking it into the CFG.
-  BasicBlock *NewBB = BasicBlock::Create(TI->getContext(),
-                      TIBB->getName() + "." + DestBB->getName() + "_crit_edge");
+  BasicBlock *NewBB = nullptr;
+  if (BBName.str() != "")
+    NewBB = BasicBlock::Create(TI->getContext(), BBName);
+  else
+    NewBB = BasicBlock::Create(TI->getContext(), TIBB->getName() + "." +
+                                                     DestBB->getName() +
+                                                     "_crit_edge");
   // Create our unconditional branch.
   BranchInst *NewBI = BranchInst::Create(DestBB, NewBB);
   NewBI->setDebugLoc(TI->getDebugLoc());