Restructure PEI code:
- moved shrink wrapping code from PrologEpilogInserter.cpp to
new file ShrinkWrapping.cpp.
- moved PEI pass definition into new shared header PEI.h.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71588 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/PEI.h b/lib/CodeGen/PEI.h
new file mode 100644
index 0000000..c158dd8
--- /dev/null
+++ b/lib/CodeGen/PEI.h
@@ -0,0 +1,167 @@
+//===-- PrologEpilogInserter.h - Prolog/Epilog code insertion -*- C++ -* --===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This pass is responsible for finalizing the functions frame layout, saving
+// callee saved registers, and for emitting prolog & epilog code for the
+// function.
+//
+// This pass must be run after register allocation. After this pass is
+// executed, it is illegal to construct MO_FrameIndex operands.
+//
+// This pass also implements a shrink wrapping variant of prolog/epilog
+// insertion.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CODEGEN_PEI_H
+#define LLVM_CODEGEN_PEI_H
+
+#include "llvm/CodeGen/Passes.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineLoopInfo.h"
+#include "llvm/ADT/SparseBitVector.h"
+#include "llvm/ADT/DenseMap.h"
+
+namespace llvm {
+ class RegScavenger;
+ class MachineBasicBlock;
+
+ class PEI : public MachineFunctionPass {
+ public:
+ static char ID;
+ PEI() : MachineFunctionPass(&ID) {}
+
+ const char *getPassName() const {
+ return "Prolog/Epilog Insertion & Frame Finalization";
+ }
+
+ virtual void getAnalysisUsage(AnalysisUsage &AU) const;
+
+ /// runOnMachineFunction - Insert prolog/epilog code and replace abstract
+ /// frame indexes with appropriate references.
+ ///
+ bool runOnMachineFunction(MachineFunction &Fn);
+
+ private:
+ RegScavenger *RS;
+
+ // MinCSFrameIndex, MaxCSFrameIndex - Keeps the range of callee saved
+ // stack frame indexes.
+ unsigned MinCSFrameIndex, MaxCSFrameIndex;
+
+ // Analysis info for spill/restore placement.
+ // "CSR": "callee saved register".
+
+ // CSRegSet contains indices into the Callee Saved Register Info
+ // vector built by calculateCalleeSavedRegisters() and accessed
+ // via MF.getFrameInfo()->getCalleeSavedInfo().
+ typedef SparseBitVector<> CSRegSet;
+
+ // CSRegBlockMap maps MachineBasicBlocks to sets of callee
+ // saved register indices.
+ typedef DenseMap<MachineBasicBlock*, CSRegSet> CSRegBlockMap;
+
+ // Set and maps for computing CSR spill/restore placement:
+ // used in function (UsedCSRegs)
+ // used in a basic block (CSRUsed)
+ // anticipatable in a basic block (Antic{In,Out})
+ // available in a basic block (Avail{In,Out})
+ // to be spilled at the entry to a basic block (CSRSave)
+ // to be restored at the end of a basic block (CSRRestore)
+ CSRegSet UsedCSRegs;
+ CSRegBlockMap CSRUsed;
+ CSRegBlockMap AnticIn, AnticOut;
+ CSRegBlockMap AvailIn, AvailOut;
+ CSRegBlockMap CSRSave;
+ CSRegBlockMap CSRRestore;
+
+ // Entry and return blocks of the current function.
+ MachineBasicBlock* EntryBlock;
+ SmallVector<MachineBasicBlock*, 4> ReturnBlocks;
+
+ // Map of MBBs to top level MachineLoops.
+ DenseMap<MachineBasicBlock*, MachineLoop*> TLLoops;
+
+ // Flag to control shrink wrapping per-function:
+ // may choose to skip shrink wrapping for certain
+ // functions.
+ bool ShrinkWrapThisFunction;
+
+#ifndef NDEBUG
+ // Machine function handle.
+ MachineFunction* MF;
+
+ // Flag indicating that the current function
+ // has at least one "short" path in the machine
+ // CFG from the entry block to an exit block.
+ bool HasFastExitPath;
+#endif
+
+ bool calculateSets(MachineFunction &Fn);
+ bool calcAnticInOut(MachineBasicBlock* MBB);
+ bool calcAvailInOut(MachineBasicBlock* MBB);
+ void calculateAnticAvail(MachineFunction &Fn);
+ bool addUsesForMEMERegion(MachineBasicBlock* MBB,
+ SmallVector<MachineBasicBlock*, 4>& blks);
+ bool addUsesForTopLevelLoops(SmallVector<MachineBasicBlock*, 4>& blks);
+ bool calcSpillPlacements(MachineBasicBlock* MBB,
+ SmallVector<MachineBasicBlock*, 4> &blks,
+ CSRegBlockMap &prevSpills);
+ bool calcRestorePlacements(MachineBasicBlock* MBB,
+ SmallVector<MachineBasicBlock*, 4> &blks,
+ CSRegBlockMap &prevRestores);
+ void placeSpillsAndRestores(MachineFunction &Fn);
+ void placeCSRSpillsAndRestores(MachineFunction &Fn);
+ void calculateCalleeSavedRegisters(MachineFunction &Fn);
+ void insertCSRSpillsAndRestores(MachineFunction &Fn);
+ void calculateFrameObjectOffsets(MachineFunction &Fn);
+ void replaceFrameIndices(MachineFunction &Fn);
+ void insertPrologEpilogCode(MachineFunction &Fn);
+
+ // Initialize DFA sets, called before iterations.
+ void clearAnticAvailSets();
+ // Clear all sets constructed by shrink wrapping.
+ void clearAllSets();
+
+ // Initialize all shrink wrapping data.
+ void initShrinkWrappingInfo();
+
+ // Convienences for dealing with machine loops.
+ MachineBasicBlock* getTopLevelLoopPreheader(MachineLoop* LP);
+ MachineLoop* getTopLevelLoopParent(MachineLoop *LP);
+
+ // Propgate CSRs used in MBB to all MBBs of loop LP.
+ void propagateUsesAroundLoop(MachineBasicBlock* MBB, MachineLoop* LP);
+
+ // Convenience for recognizing return blocks.
+ bool isReturnBlock(MachineBasicBlock* MBB);
+
+#ifndef NDEBUG
+ // Debugging methods.
+
+ // Mark this function as having fast exit paths.
+ void findFastExitPath();
+
+ // Verify placement of spills/restores.
+ void verifySpillRestorePlacement();
+
+ std::string getBasicBlockName(const MachineBasicBlock* MBB);
+ std::string stringifyCSRegSet(const CSRegSet& s);
+ void dumpSet(const CSRegSet& s);
+ void dumpUsed(MachineBasicBlock* MBB);
+ void dumpAllUsed();
+ void dumpSets(MachineBasicBlock* MBB);
+ void dumpSets1(MachineBasicBlock* MBB);
+ void dumpAllSets();
+ void dumpSRSets();
+#endif
+
+ };
+} // End llvm namespace
+#endif