[llvm] r258654 - [SCCP] Remove duplicate code

[David Majnemer via llvm-commits]

Author: majnemer
Date: Sun Jan 24 00:26:47 2016
New Revision: 258654

URL: http://llvm.org/viewvc/llvm-project?rev=258654&view=rev
Log:
[SCCP] Remove duplicate code

SCCP has code identical to changeToUnreachable's behavior, switch it
over to just call changeToUnreachable.

No functionality change intended.

Modified:
    llvm/trunk/include/llvm/Transforms/Utils/Local.h
    llvm/trunk/lib/Transforms/Scalar/SCCP.cpp
    llvm/trunk/lib/Transforms/Utils/Local.cpp

Modified: llvm/trunk/include/llvm/Transforms/Utils/Local.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Transforms/Utils/Local.h?rev=258654&r1=258653&r2=258654&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Transforms/Utils/Local.h (original)
+++ llvm/trunk/include/llvm/Transforms/Utils/Local.h Sun Jan 24 00:26:47 2016
@@ -295,7 +295,7 @@ unsigned removeAllNonTerminatorAndEHPadI
 
 /// \brief Insert an unreachable instruction before the specified
 /// instruction, making it and the rest of the code in the block dead.
-void changeToUnreachable(Instruction *I, bool UseLLVMTrap);
+unsigned changeToUnreachable(Instruction *I, bool UseLLVMTrap);
 
 /// Replace 'BB's terminator with one that does not have an unwind successor
 /// block.  Rewrites `invoke` to `call`, etc.  Updates any PHIs in unwind

Modified: llvm/trunk/lib/Transforms/Scalar/SCCP.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/SCCP.cpp?rev=258654&r1=258653&r2=258654&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/SCCP.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/SCCP.cpp Sun Jan 24 00:26:47 2016
@@ -1564,14 +1564,6 @@ FunctionPass *llvm::createSCCPPass() {
   return new SCCP();
 }
 
-static void DeleteInstructionInBlock(BasicBlock *BB) {
-  DEBUG(dbgs() << "  BasicBlock Dead:" << *BB);
-  ++NumDeadBlocks;
-
-  unsigned NumRemovedInBB = removeAllNonTerminatorAndEHPadInstructions(BB);
-  NumInstRemoved += NumRemovedInBB;
-}
-
 // runOnFunction() - Run the Sparse Conditional Constant Propagation algorithm,
 // and return true if the function was modified.
 //
@@ -1608,7 +1600,11 @@ bool SCCP::runOnFunction(Function &F) {
 
   for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
     if (!Solver.isBlockExecutable(&*BB)) {
-      DeleteInstructionInBlock(&*BB);
+      DEBUG(dbgs() << "  BasicBlock Dead:" << *BB);
+
+      ++NumDeadBlocks;
+      NumInstRemoved += removeAllNonTerminatorAndEHPadInstructions(BB);
+
       MadeChanges = true;
       continue;
     }
@@ -1806,18 +1802,13 @@ bool IPSCCP::runOnModule(Module &M) {
 
     for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
       if (!Solver.isBlockExecutable(&*BB)) {
-        DeleteInstructionInBlock(&*BB);
-        MadeChanges = true;
+        DEBUG(dbgs() << "  BasicBlock Dead:" << *BB);
 
-        TerminatorInst *TI = BB->getTerminator();
-        for (BasicBlock *Succ : TI->successors()) {
-          if (!Succ->empty() && isa<PHINode>(Succ->begin()))
-            Succ->removePredecessor(&*BB);
-        }
-        if (!TI->use_empty())
-          TI->replaceAllUsesWith(UndefValue::get(TI->getType()));
-        TI->eraseFromParent();
-        new UnreachableInst(M.getContext(), &*BB);
+        ++NumDeadBlocks;
+        NumInstRemoved +=
+            changeToUnreachable(&*BB->begin(), /*UseLLVMTrap=*/false);
+
+        MadeChanges = true;
 
         if (&*BB != &F->front())
           BlocksToErase.push_back(&*BB);

Modified: llvm/trunk/lib/Transforms/Utils/Local.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/Local.cpp?rev=258654&r1=258653&r2=258654&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/Local.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/Local.cpp Sun Jan 24 00:26:47 2016
@@ -1243,7 +1243,7 @@ unsigned llvm::removeAllNonTerminatorAnd
   return NumDeadInst;
 }
 
-void llvm::changeToUnreachable(Instruction *I, bool UseLLVMTrap) {
+unsigned llvm::changeToUnreachable(Instruction *I, bool UseLLVMTrap) {
   BasicBlock *BB = I->getParent();
   // Loop over all of the successors, removing BB's entry from any PHI
   // nodes.
@@ -1261,12 +1261,15 @@ void llvm::changeToUnreachable(Instructi
   new UnreachableInst(I->getContext(), I);
 
   // All instructions after this are dead.
+  unsigned NumInstrsRemoved = 0;
   BasicBlock::iterator BBI = I->getIterator(), BBE = BB->end();
   while (BBI != BBE) {
     if (!BBI->use_empty())
       BBI->replaceAllUsesWith(UndefValue::get(BBI->getType()));
     BB->getInstList().erase(BBI++);
+    ++NumInstrsRemoved;
   }
+  return NumInstrsRemoved;
 }
 
 /// changeToCall - Convert the specified invoke into a normal call.