1 files changed, 79 insertions, 0 deletions
diff --git a/lib/Transforms/Utils/BasicBlockUtils.cpp b/lib/Transforms/Utils/BasicBlockUtils.cpp
new file mode 100644
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+++ b/lib/Transforms/Utils/BasicBlockUtils.cpp
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+//===-- BasicBlockUtils.cpp - BasicBlock Utilities -------------------------==//
+//
+// This family of functions perform manipulations on basic blocks, and
+// instructions contained within basic blocks.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Transforms/Utils/BasicBlockUtils.h"
+#include "llvm/Function.h"
+#include "llvm/Instruction.h"
+#include <algorithm>
+
+// ReplaceInstWithValue - Replace all uses of an instruction (specified by BI)
+// with a value, then remove and delete the original instruction.
+//
+void ReplaceInstWithValue(BasicBlock::InstListType &BIL,
+                          BasicBlock::iterator &BI, Value *V) {
+  Instruction *I = *BI;
+  // Replaces all of the uses of the instruction with uses of the value
+  I->replaceAllUsesWith(V);
+
+  // Remove the unneccesary instruction now...
+  BIL.remove(BI);
+
+  // Make sure to propogate a name if there is one already...
+  if (I->hasName() && !V->hasName())
+    V->setName(I->getName(), BIL.getParent()->getSymbolTable());
+
+  // Remove the dead instruction now...
+  delete I;
+}
+
+
+// ReplaceInstWithInst - Replace the instruction specified by BI with the
+// instruction specified by I.  The original instruction is deleted and BI is
+// updated to point to the new instruction.
+//
+void ReplaceInstWithInst(BasicBlock::InstListType &BIL,
+                         BasicBlock::iterator &BI, Instruction *I) {
+  assert(I->getParent() == 0 &&
+         "ReplaceInstWithInst: Instruction already inserted into basic block!");
+
+  // Insert the new instruction into the basic block...
+  BI = BIL.insert(BI, I)+1;  // Increment BI to point to instruction to delete
+
+  // Replace all uses of the old instruction, and delete it.
+  ReplaceInstWithValue(BIL, BI, I);
+
+  // Move BI back to point to the newly inserted instruction
+  --BI;
+}
+
+// ReplaceInstWithInst - Replace the instruction specified by From with the
+// instruction specified by To.  Note that this is slower than providing an
+// iterator directly, because the basic block containing From must be searched
+// for the instruction.
+//
+void ReplaceInstWithInst(Instruction *From, Instruction *To) {
+  BasicBlock *BB = From->getParent();
+  BasicBlock::InstListType &BIL = BB->getInstList();
+  BasicBlock::iterator BI = find(BIL.begin(), BIL.end(), From);
+  assert(BI != BIL.end() && "Inst not in it's parents BB!");
+  ReplaceInstWithInst(BIL, BI, To);
+}
+
+// InsertInstBeforeInst - Insert 'NewInst' into the basic block that 'Existing'
+// is already in, and put it right before 'Existing'.  This instruction should
+// only be used when there is no iterator to Existing already around.  The 
+// returned iterator points to the new instruction.
+//
+BasicBlock::iterator InsertInstBeforeInst(Instruction *NewInst,
+                                          Instruction *Existing) {
+  BasicBlock *BB = Existing->getParent();
+  BasicBlock::InstListType &BIL = BB->getInstList();
+  BasicBlock::iterator BI = find(BIL.begin(), BIL.end(), Existing);
+  assert(BI != BIL.end() && "Inst not in it's parents BB!");
+  return BIL.insert(BI, NewInst);
+}
+