Add BasicInliner interface.

[oota-llvm.git] / include / llvm / Transforms / Utils / BasicBlockUtils.h

diff --git a/include/llvm/Transforms/Utils/BasicBlockUtils.h b/include/llvm/Transforms/Utils/BasicBlockUtils.h
index 53452eb1cd781a0444cd02108ecd95489ff895ae..47bbcbec6d71405ec53524d0b457211a9242c70d 100644 (file)
--- a/include/llvm/Transforms/Utils/BasicBlockUtils.h
+++ b/include/llvm/Transforms/Utils/BasicBlockUtils.h
@@ -1,10 +1,10 @@
 //===-- Transform/Utils/BasicBlockUtils.h - BasicBlock Utils ----*- C++ -*-===//
-// 
+//
 //                     The LLVM Compiler Infrastructure
 //
 // This file was developed by the LLVM research group and is distributed under
 // the University of Illinois Open Source License. See LICENSE.TXT for details.
-// 
+//
 //===----------------------------------------------------------------------===//
 //
 // This family of functions perform manipulations on basic blocks, and
@@ -18,7 +18,12 @@
 // FIXME: Move to this file: BasicBlock::removePredecessor, BB::splitBasicBlock
 
 #include "llvm/BasicBlock.h"
+#include "llvm/Support/CFG.h"
+
+namespace llvm {
+
 class Instruction;
+class Pass;
 
 // ReplaceInstWithValue - Replace all uses of an instruction (specified by BI)
 // with a value, then remove and delete the original instruction.
@@ -48,4 +53,71 @@ void ReplaceInstWithInst(Instruction *From, Instruction *To);
 //
 void RemoveSuccessor(TerminatorInst *TI, unsigned SuccNum);
 
+/// isCriticalEdge - Return true if the specified edge is a critical edge.
+/// Critical edges are edges from a block with multiple successors to a block
+/// with multiple predecessors.
+///
+bool isCriticalEdge(const TerminatorInst *TI, unsigned SuccNum,
+                    bool AllowIdenticalEdges = false);
+
+/// SplitCriticalEdge - If this edge is a critical edge, insert a new node to
+/// split the critical edge.  This will update DominatorTree, and DominatorFrontier 
+/// information if it is available, thus calling this pass will not invalidate 
+/// either of them. This returns true if the edge was split, false otherwise.  
+/// If MergeIdenticalEdges is true (the default), *all* edges from TI to the 
+/// specified successor will be merged into the same critical edge block.  
+/// This is most commonly interesting with switch instructions, which may 
+/// have many edges to any one destination.  This ensures that all edges to that 
+/// dest go to one block instead of each going to a different block, but isn't 
+/// the standard definition of a "critical edge".
+///
+bool SplitCriticalEdge(TerminatorInst *TI, unsigned SuccNum, Pass *P = 0,
+                       bool MergeIdenticalEdges = false);
+
+inline bool SplitCriticalEdge(BasicBlock *BB, succ_iterator SI, Pass *P = 0) {
+  return SplitCriticalEdge(BB->getTerminator(), SI.getSuccessorIndex(), P);
+}
+
+/// SplitCriticalEdge - If the edge from *PI to BB is not critical, return
+/// false.  Otherwise, split all edges between the two blocks and return true.
+/// This updates all of the same analyses as the other SplitCriticalEdge
+/// function.  If P is specified, it updates the analyses
+/// described above.
+inline bool SplitCriticalEdge(BasicBlock *Succ, pred_iterator PI, Pass *P = 0) {
+  bool MadeChange = false;
+  TerminatorInst *TI = (*PI)->getTerminator();
+  for (unsigned i = 0, e = TI->getNumSuccessors(); i != e; ++i)
+    if (TI->getSuccessor(i) == Succ)
+      MadeChange |= SplitCriticalEdge(TI, i, P);
+  return MadeChange;
+}
+
+/// SplitCriticalEdge - If an edge from Src to Dst is critical, split the edge
+/// and return true, otherwise return false.  This method requires that there be
+/// an edge between the two blocks.  If P is specified, it updates the analyses
+/// described above.
+inline bool SplitCriticalEdge(BasicBlock *Src, BasicBlock *Dst, Pass *P = 0,
+                              bool MergeIdenticalEdges = false) {
+  TerminatorInst *TI = Src->getTerminator();
+  unsigned i = 0;
+  while (1) {
+    assert(i != TI->getNumSuccessors() && "Edge doesn't exist!");
+    if (TI->getSuccessor(i) == Dst)
+      return SplitCriticalEdge(TI, i, P, MergeIdenticalEdges);
+    ++i;
+  }
+}
+
+/// SplitEdge -  Split the edge connecting specified block. Pass P must 
+/// not be NULL. 
+BasicBlock *SplitEdge(BasicBlock *From, BasicBlock *To, Pass *P);
+
+/// SplitBlock - Split the specified block at the specified instruction - every
+/// thing before SplitPt stays in Old and everything starting with SplitPt moves
+/// to a new block.  The two blocks are joined by an unconditional branch and
+/// the loop info is updated.
+///
+BasicBlock *SplitBlock(BasicBlock *Old, Instruction *SplitPt, Pass *P);
+} // End llvm namespace
+
 #endif