Factor code out to the TransformUtils library

llvm-svn: 2516

1 files changed, 2 insertions, 80 deletions

diff --git a/llvm/lib/Transforms/Scalar/ConstantProp.cpp b/llvm/lib/Transforms/Scalar/ConstantProp.cpp
index b43f23745aa..7085ef98006 100644
--- a/llvm/lib/Transforms/Scalar/ConstantProp.cpp
+++ b/llvm/lib/Transforms/Scalar/ConstantProp.cpp
@@ -12,91 +12,13 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Transforms/Scalar/ConstantProp.h"
+#include "llvm/Transforms/Utils/Local.h"
 #include "llvm/ConstantHandling.h"
-#include "llvm/Function.h"
-#include "llvm/BasicBlock.h"
-#include "llvm/iTerminators.h"
+#include "llvm/Instruction.h"
 #include "llvm/Pass.h"
 #include "llvm/Support/InstIterator.h"
 #include <set>
 
-// FIXME: ConstantFoldInstruction & ConstantFoldTerminator should be moved out
-// to the Transformations library.
-
-// ConstantFoldInstruction - If an instruction references constants, try to fold
-// them together...
-//
-bool doConstantPropogation(BasicBlock *BB, BasicBlock::iterator &II) {
-  Instruction *Inst = *II;
-  if (Constant *C = ConstantFoldInstruction(Inst)) {
-    // Replaces all of the uses of a variable with uses of the constant.
-    Inst->replaceAllUsesWith(C);
-    
-    // Remove the instruction from the basic block...
-    delete BB->getInstList().remove(II);
-    return true;
-  }
-
-  return false;
-}
-
-// ConstantFoldTerminator - If a terminator instruction is predicated on a
-// constant value, convert it into an unconditional branch to the constant
-// destination.
-//
-bool ConstantFoldTerminator(BasicBlock *BB, BasicBlock::iterator &II,
-                            TerminatorInst *T) {
-  // Branch - See if we are conditional jumping on constant
-  if (BranchInst *BI = dyn_cast<BranchInst>(T)) {
-    if (BI->isUnconditional()) return false;  // Can't optimize uncond branch
-    BasicBlock *Dest1 = cast<BasicBlock>(BI->getOperand(0));
-    BasicBlock *Dest2 = cast<BasicBlock>(BI->getOperand(1));
-
-    if (ConstantBool *Cond = dyn_cast<ConstantBool>(BI->getCondition())) {
-      // Are we branching on constant?
-      // YES.  Change to unconditional branch...
-      BasicBlock *Destination = Cond->getValue() ? Dest1 : Dest2;
-      BasicBlock *OldDest     = Cond->getValue() ? Dest2 : Dest1;
-
-      //cerr << "Function: " << T->getParent()->getParent() 
-      //     << "\nRemoving branch from " << T->getParent() 
-      //     << "\n\nTo: " << OldDest << endl;
-
-      // Let the basic block know that we are letting go of it.  Based on this,
-      // it will adjust it's PHI nodes.
-      assert(BI->getParent() && "Terminator not inserted in block!");
-      OldDest->removePredecessor(BI->getParent());
-
-      // Set the unconditional destination, and change the insn to be an
-      // unconditional branch.
-      BI->setUnconditionalDest(Destination);
-      II = BB->end()-1;  // Update instruction iterator!
-      return true;
-    }
-#if 0
-    // FIXME: TODO: This doesn't work if the destination has PHI nodes with
-    // different incoming values on each branch!
-    //
-    else if (Dest2 == Dest1) {       // Conditional branch to same location?
-      // This branch matches something like this:  
-      //     br bool %cond, label %Dest, label %Dest
-      // and changes it into:  br label %Dest
-
-      // Let the basic block know that we are letting go of one copy of it.
-      assert(BI->getParent() && "Terminator not inserted in block!");
-      Dest1->removePredecessor(BI->getParent());
-
-      // Change a conditional branch to unconditional.
-      BI->setUnconditionalDest(Dest1);
-      return true;
-    }
-#endif
-  }
-  return false;
-}
-
-
-
 namespace {
   struct ConstantPropogation : public FunctionPass {
     const char *getPassName() const { return "Simple Constant Propogation"; }