llvm-6502/include/llvm/CodeGen/Passes.h
Nadav Rotem c05d30601c Add a new optimization pass: Stack Coloring, that merges disjoint static allocations (allocas). Allocas are known to be
disjoint if they are marked by disjoint lifetime markers (@llvm.lifetime.XXX intrinsics).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163299 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-06 09:17:37 +00:00

515 lines
19 KiB
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//===-- Passes.h - Target independent code generation passes ----*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines interfaces to access the target independent code generation
// passes provided by the LLVM backend.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_PASSES_H
#define LLVM_CODEGEN_PASSES_H
#include "llvm/Pass.h"
#include "llvm/Target/TargetMachine.h"
#include <string>
namespace llvm {
class FunctionPass;
class MachineFunctionPass;
class PassInfo;
class PassManagerBase;
class TargetLowering;
class TargetRegisterClass;
class raw_ostream;
}
namespace llvm {
class PassConfigImpl;
/// Target-Independent Code Generator Pass Configuration Options.
///
/// This is an ImmutablePass solely for the purpose of exposing CodeGen options
/// to the internals of other CodeGen passes.
class TargetPassConfig : public ImmutablePass {
public:
/// Pseudo Pass IDs. These are defined within TargetPassConfig because they
/// are unregistered pass IDs. They are only useful for use with
/// TargetPassConfig APIs to identify multiple occurrences of the same pass.
///
/// EarlyTailDuplicate - A clone of the TailDuplicate pass that runs early
/// during codegen, on SSA form.
static char EarlyTailDuplicateID;
/// PostRAMachineLICM - A clone of the LICM pass that runs during late machine
/// optimization after regalloc.
static char PostRAMachineLICMID;
private:
PassManagerBase *PM;
AnalysisID StartAfter;
AnalysisID StopAfter;
bool Started;
bool Stopped;
protected:
TargetMachine *TM;
PassConfigImpl *Impl; // Internal data structures
bool Initialized; // Flagged after all passes are configured.
// Target Pass Options
// Targets provide a default setting, user flags override.
//
bool DisableVerify;
/// Default setting for -enable-tail-merge on this target.
bool EnableTailMerge;
public:
TargetPassConfig(TargetMachine *tm, PassManagerBase &pm);
// Dummy constructor.
TargetPassConfig();
virtual ~TargetPassConfig();
static char ID;
/// Get the right type of TargetMachine for this target.
template<typename TMC> TMC &getTM() const {
return *static_cast<TMC*>(TM);
}
const TargetLowering *getTargetLowering() const {
return TM->getTargetLowering();
}
//
void setInitialized() { Initialized = true; }
CodeGenOpt::Level getOptLevel() const { return TM->getOptLevel(); }
/// setStartStopPasses - Set the StartAfter and StopAfter passes to allow
/// running only a portion of the normal code-gen pass sequence. If the
/// Start pass ID is zero, then compilation will begin at the normal point;
/// otherwise, clear the Started flag to indicate that passes should not be
/// added until the starting pass is seen. If the Stop pass ID is zero,
/// then compilation will continue to the end.
void setStartStopPasses(AnalysisID Start, AnalysisID Stop) {
StartAfter = Start;
StopAfter = Stop;
Started = (StartAfter == 0);
}
void setDisableVerify(bool Disable) { setOpt(DisableVerify, Disable); }
bool getEnableTailMerge() const { return EnableTailMerge; }
void setEnableTailMerge(bool Enable) { setOpt(EnableTailMerge, Enable); }
/// Allow the target to override a specific pass without overriding the pass
/// pipeline. When passes are added to the standard pipeline at the
/// point where StandardID is expected, add TargetID in its place.
void substitutePass(AnalysisID StandardID, AnalysisID TargetID);
/// Insert InsertedPassID pass after TargetPassID pass.
void insertPass(AnalysisID TargetPassID, AnalysisID InsertedPassID);
/// Allow the target to enable a specific standard pass by default.
void enablePass(AnalysisID PassID) { substitutePass(PassID, PassID); }
/// Allow the target to disable a specific standard pass by default.
void disablePass(AnalysisID PassID) { substitutePass(PassID, 0); }
/// Return the pass substituted for StandardID by the target.
/// If no substitution exists, return StandardID.
AnalysisID getPassSubstitution(AnalysisID StandardID) const;
/// Return true if the optimized regalloc pipeline is enabled.
bool getOptimizeRegAlloc() const;
/// Add common target configurable passes that perform LLVM IR to IR
/// transforms following machine independent optimization.
virtual void addIRPasses();
/// Add passes to lower exception handling for the code generator.
void addPassesToHandleExceptions();
/// Add common passes that perform LLVM IR to IR transforms in preparation for
/// instruction selection.
virtual void addISelPrepare();
/// addInstSelector - This method should install an instruction selector pass,
/// which converts from LLVM code to machine instructions.
virtual bool addInstSelector() {
return true;
}
/// Add the complete, standard set of LLVM CodeGen passes.
/// Fully developed targets will not generally override this.
virtual void addMachinePasses();
protected:
// Helper to verify the analysis is really immutable.
void setOpt(bool &Opt, bool Val);
/// Methods with trivial inline returns are convenient points in the common
/// codegen pass pipeline where targets may insert passes. Methods with
/// out-of-line standard implementations are major CodeGen stages called by
/// addMachinePasses. Some targets may override major stages when inserting
/// passes is insufficient, but maintaining overriden stages is more work.
///
/// addPreISelPasses - This method should add any "last minute" LLVM->LLVM
/// passes (which are run just before instruction selector).
virtual bool addPreISel() {
return true;
}
/// addMachineSSAOptimization - Add standard passes that optimize machine
/// instructions in SSA form.
virtual void addMachineSSAOptimization();
/// addPreRegAlloc - This method may be implemented by targets that want to
/// run passes immediately before register allocation. This should return
/// true if -print-machineinstrs should print after these passes.
virtual bool addPreRegAlloc() {
return false;
}
/// createTargetRegisterAllocator - Create the register allocator pass for
/// this target at the current optimization level.
virtual FunctionPass *createTargetRegisterAllocator(bool Optimized);
/// addFastRegAlloc - Add the minimum set of target-independent passes that
/// are required for fast register allocation.
virtual void addFastRegAlloc(FunctionPass *RegAllocPass);
/// addOptimizedRegAlloc - Add passes related to register allocation.
/// LLVMTargetMachine provides standard regalloc passes for most targets.
virtual void addOptimizedRegAlloc(FunctionPass *RegAllocPass);
/// addPreRewrite - Add passes to the optimized register allocation pipeline
/// after register allocation is complete, but before virtual registers are
/// rewritten to physical registers.
///
/// These passes must preserve VirtRegMap and LiveIntervals, and when running
/// after RABasic or RAGreedy, they should take advantage of LiveRegMatrix.
/// When these passes run, VirtRegMap contains legal physreg assignments for
/// all virtual registers.
virtual bool addPreRewrite() {
return false;
}
/// addFinalizeRegAlloc - This method may be implemented by targets that want
/// to run passes within the regalloc pipeline, immediately after the register
/// allocation pass itself. These passes run as soon as virtual regisiters
/// have been rewritten to physical registers but before and other postRA
/// optimization happens. Targets that have marked instructions for bundling
/// must have finalized those bundles by the time these passes have run,
/// because subsequent passes are not guaranteed to be bundle-aware.
virtual bool addFinalizeRegAlloc() {
return false;
}
/// addPostRegAlloc - This method may be implemented by targets that want to
/// run passes after register allocation pass pipeline but before
/// prolog-epilog insertion. This should return true if -print-machineinstrs
/// should print after these passes.
virtual bool addPostRegAlloc() {
return false;
}
/// Add passes that optimize machine instructions after register allocation.
virtual void addMachineLateOptimization();
/// addPreSched2 - This method may be implemented by targets that want to
/// run passes after prolog-epilog insertion and before the second instruction
/// scheduling pass. This should return true if -print-machineinstrs should
/// print after these passes.
virtual bool addPreSched2() {
return false;
}
/// Add standard basic block placement passes.
virtual void addBlockPlacement();
/// addPreEmitPass - This pass may be implemented by targets that want to run
/// passes immediately before machine code is emitted. This should return
/// true if -print-machineinstrs should print out the code after the passes.
virtual bool addPreEmitPass() {
return false;
}
/// Utilities for targets to add passes to the pass manager.
///
/// Add a CodeGen pass at this point in the pipeline after checking overrides.
/// Return the pass that was added, or zero if no pass was added.
AnalysisID addPass(AnalysisID PassID);
/// Add a pass to the PassManager if that pass is supposed to be run, as
/// determined by the StartAfter and StopAfter options.
void addPass(Pass *P);
/// addMachinePasses helper to create the target-selected or overriden
/// regalloc pass.
FunctionPass *createRegAllocPass(bool Optimized);
/// printAndVerify - Add a pass to dump then verify the machine function, if
/// those steps are enabled.
///
void printAndVerify(const char *Banner);
};
} // namespace llvm
/// List of target independent CodeGen pass IDs.
namespace llvm {
/// createUnreachableBlockEliminationPass - The LLVM code generator does not
/// work well with unreachable basic blocks (what live ranges make sense for a
/// block that cannot be reached?). As such, a code generator should either
/// not instruction select unreachable blocks, or run this pass as its
/// last LLVM modifying pass to clean up blocks that are not reachable from
/// the entry block.
FunctionPass *createUnreachableBlockEliminationPass();
/// MachineFunctionPrinter pass - This pass prints out the machine function to
/// the given stream as a debugging tool.
MachineFunctionPass *
createMachineFunctionPrinterPass(raw_ostream &OS,
const std::string &Banner ="");
/// MachineLoopInfo - This pass is a loop analysis pass.
extern char &MachineLoopInfoID;
/// MachineLoopRanges - This pass is an on-demand loop coverage analysis.
extern char &MachineLoopRangesID;
/// MachineDominators - This pass is a machine dominators analysis pass.
extern char &MachineDominatorsID;
/// EdgeBundles analysis - Bundle machine CFG edges.
extern char &EdgeBundlesID;
/// LiveVariables pass - This pass computes the set of blocks in which each
/// variable is life and sets machine operand kill flags.
extern char &LiveVariablesID;
/// PHIElimination - This pass eliminates machine instruction PHI nodes
/// by inserting copy instructions. This destroys SSA information, but is the
/// desired input for some register allocators. This pass is "required" by
/// these register allocator like this: AU.addRequiredID(PHIEliminationID);
extern char &PHIEliminationID;
/// StrongPHIElimination - This pass eliminates machine instruction PHI
/// nodes by inserting copy instructions. This destroys SSA information, but
/// is the desired input for some register allocators. This pass is
/// "required" by these register allocator like this:
/// AU.addRequiredID(PHIEliminationID);
/// This pass is still in development
extern char &StrongPHIEliminationID;
/// LiveIntervals - This analysis keeps track of the live ranges of virtual
/// and physical registers.
extern char &LiveIntervalsID;
/// LiveStacks pass. An analysis keeping track of the liveness of stack slots.
extern char &LiveStacksID;
/// TwoAddressInstruction - This pass reduces two-address instructions to
/// use two operands. This destroys SSA information but it is desired by
/// register allocators.
extern char &TwoAddressInstructionPassID;
/// ProcessImpicitDefs pass - This pass removes IMPLICIT_DEFs.
extern char &ProcessImplicitDefsID;
/// RegisterCoalescer - This pass merges live ranges to eliminate copies.
extern char &RegisterCoalescerID;
/// MachineScheduler - This pass schedules machine instructions.
extern char &MachineSchedulerID;
/// SpillPlacement analysis. Suggest optimal placement of spill code between
/// basic blocks.
extern char &SpillPlacementID;
/// VirtRegRewriter pass. Rewrite virtual registers to physical registers as
/// assigned in VirtRegMap.
extern char &VirtRegRewriterID;
/// UnreachableMachineBlockElimination - This pass removes unreachable
/// machine basic blocks.
extern char &UnreachableMachineBlockElimID;
/// DeadMachineInstructionElim - This pass removes dead machine instructions.
extern char &DeadMachineInstructionElimID;
/// FastRegisterAllocation Pass - This pass register allocates as fast as
/// possible. It is best suited for debug code where live ranges are short.
///
FunctionPass *createFastRegisterAllocator();
/// BasicRegisterAllocation Pass - This pass implements a degenerate global
/// register allocator using the basic regalloc framework.
///
FunctionPass *createBasicRegisterAllocator();
/// Greedy register allocation pass - This pass implements a global register
/// allocator for optimized builds.
///
FunctionPass *createGreedyRegisterAllocator();
/// PBQPRegisterAllocation Pass - This pass implements the Partitioned Boolean
/// Quadratic Prograaming (PBQP) based register allocator.
///
FunctionPass *createDefaultPBQPRegisterAllocator();
/// PrologEpilogCodeInserter - This pass inserts prolog and epilog code,
/// and eliminates abstract frame references.
extern char &PrologEpilogCodeInserterID;
/// ExpandPostRAPseudos - This pass expands pseudo instructions after
/// register allocation.
extern char &ExpandPostRAPseudosID;
/// createPostRAScheduler - This pass performs post register allocation
/// scheduling.
extern char &PostRASchedulerID;
/// BranchFolding - This pass performs machine code CFG based
/// optimizations to delete branches to branches, eliminate branches to
/// successor blocks (creating fall throughs), and eliminating branches over
/// branches.
extern char &BranchFolderPassID;
/// MachineFunctionPrinterPass - This pass prints out MachineInstr's.
extern char &MachineFunctionPrinterPassID;
/// TailDuplicate - Duplicate blocks with unconditional branches
/// into tails of their predecessors.
extern char &TailDuplicateID;
/// MachineTraceMetrics - This pass computes critical path and CPU resource
/// usage in an ensemble of traces.
extern char &MachineTraceMetricsID;
/// EarlyIfConverter - This pass performs if-conversion on SSA form by
/// inserting cmov instructions.
extern char &EarlyIfConverterID;
/// StackSlotColoring - This pass performs stack coloring and merging.
/// It merges disjoint allocas to reduce the stack size.
extern char &StackColoringID;
/// IfConverter - This pass performs machine code if conversion.
extern char &IfConverterID;
/// MachineBlockPlacement - This pass places basic blocks based on branch
/// probabilities.
extern char &MachineBlockPlacementID;
/// MachineBlockPlacementStats - This pass collects statistics about the
/// basic block placement using branch probabilities and block frequency
/// information.
extern char &MachineBlockPlacementStatsID;
/// Code Placement - This pass optimize code placement and aligns loop
/// headers to target specific alignment boundary.
extern char &CodePlacementOptID;
/// GCLowering Pass - Performs target-independent LLVM IR transformations for
/// highly portable strategies.
///
FunctionPass *createGCLoweringPass();
/// GCMachineCodeAnalysis - Target-independent pass to mark safe points
/// in machine code. Must be added very late during code generation, just
/// prior to output, and importantly after all CFG transformations (such as
/// branch folding).
extern char &GCMachineCodeAnalysisID;
/// Deleter Pass - Releases GC metadata.
///
FunctionPass *createGCInfoDeleter();
/// Creates a pass to print GC metadata.
///
FunctionPass *createGCInfoPrinter(raw_ostream &OS);
/// MachineCSE - This pass performs global CSE on machine instructions.
extern char &MachineCSEID;
/// MachineLICM - This pass performs LICM on machine instructions.
extern char &MachineLICMID;
/// MachineSinking - This pass performs sinking on machine instructions.
extern char &MachineSinkingID;
/// MachineCopyPropagation - This pass performs copy propagation on
/// machine instructions.
extern char &MachineCopyPropagationID;
/// PeepholeOptimizer - This pass performs peephole optimizations -
/// like extension and comparison eliminations.
extern char &PeepholeOptimizerID;
/// OptimizePHIs - This pass optimizes machine instruction PHIs
/// to take advantage of opportunities created during DAG legalization.
extern char &OptimizePHIsID;
/// StackSlotColoring - This pass performs stack slot coloring.
extern char &StackSlotColoringID;
/// createStackProtectorPass - This pass adds stack protectors to functions.
///
FunctionPass *createStackProtectorPass(const TargetLowering *tli);
/// createMachineVerifierPass - This pass verifies cenerated machine code
/// instructions for correctness.
///
FunctionPass *createMachineVerifierPass(const char *Banner = 0);
/// createDwarfEHPass - This pass mulches exception handling code into a form
/// adapted to code generation. Required if using dwarf exception handling.
FunctionPass *createDwarfEHPass(const TargetMachine *tm);
/// createSjLjEHPreparePass - This pass adapts exception handling code to use
/// the GCC-style builtin setjmp/longjmp (sjlj) to handling EH control flow.
///
FunctionPass *createSjLjEHPreparePass(const TargetLowering *tli);
/// LocalStackSlotAllocation - This pass assigns local frame indices to stack
/// slots relative to one another and allocates base registers to access them
/// when it is estimated by the target to be out of range of normal frame
/// pointer or stack pointer index addressing.
extern char &LocalStackSlotAllocationID;
/// ExpandISelPseudos - This pass expands pseudo-instructions.
extern char &ExpandISelPseudosID;
/// createExecutionDependencyFixPass - This pass fixes execution time
/// problems with dependent instructions, such as switching execution
/// domains to match.
///
/// The pass will examine instructions using and defining registers in RC.
///
FunctionPass *createExecutionDependencyFixPass(const TargetRegisterClass *RC);
/// UnpackMachineBundles - This pass unpack machine instruction bundles.
extern char &UnpackMachineBundlesID;
/// FinalizeMachineBundles - This pass finalize machine instruction
/// bundles (created earlier, e.g. during pre-RA scheduling).
extern char &FinalizeMachineBundlesID;
} // End llvm namespace
#endif