llvm-6502/include/llvm/CodeGen/Passes.h
David Greene 2c17c4d8d9 Pluggable coalescers inplementation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41743 91177308-0d34-0410-b5e6-96231b3b80d8
2007-09-06 16:18:45 +00:00

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5.4 KiB
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//===-- Passes.h - Target independent code generation passes ----*- 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 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 <iosfwd>
#include <string>
namespace llvm {
class FunctionPass;
class PassInfo;
class TargetMachine;
class RegisterCoalescer;
/// 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 it can run this pass as it's
/// 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
/// standard error, as a debugging tool.
FunctionPass *createMachineFunctionPrinterPass(std::ostream *OS,
const std::string &Banner ="");
/// PHIElimination pass - 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 const PassInfo *PHIEliminationID;
/// SimpleRegisterCoalescing pass. Aggressively coalesces every register
/// copy it can.
///
extern const PassInfo *SimpleRegisterCoalescingID;
/// TwoAddressInstruction pass - This pass reduces two-address instructions to
/// use two operands. This destroys SSA information but it is desired by
/// register allocators.
extern const PassInfo *TwoAddressInstructionPassID;
/// Creates a register allocator as the user specified on the command line.
///
FunctionPass *createRegisterAllocator();
/// SimpleRegisterAllocation Pass - This pass converts the input machine code
/// from SSA form to use explicit registers by spilling every register. Wow,
/// great policy huh?
///
FunctionPass *createSimpleRegisterAllocator();
/// LocalRegisterAllocation Pass - This pass register allocates the input code
/// a basic block at a time, yielding code better than the simple register
/// allocator, but not as good as a global allocator.
///
FunctionPass *createLocalRegisterAllocator();
/// BigBlockRegisterAllocation Pass - The BigBlock register allocator
/// munches single basic blocks at a time, like the local register
/// allocator. While the BigBlock allocator is a little slower, and uses
/// somewhat more memory than the local register allocator, it tends to
/// yield the best allocations (of any of the allocators) for blocks that
/// have hundreds or thousands of instructions in sequence.
///
FunctionPass *createBigBlockRegisterAllocator();
/// LinearScanRegisterAllocation Pass - This pass implements the linear scan
/// register allocation algorithm, a global register allocator.
///
FunctionPass *createLinearScanRegisterAllocator();
/// SimpleRegisterCoalescing Pass - Coalesce all copies possible. Can run
/// independently of the register allocator.
///
RegisterCoalescer *createSimpleRegisterCoalescer();
/// PrologEpilogCodeInserter Pass - This pass inserts prolog and epilog code,
/// and eliminates abstract frame references.
///
FunctionPass *createPrologEpilogCodeInserter();
/// LowerSubregs Pass - This pass lowers subregs to register-register copies
/// which yields suboptimal, but correct code if the register allocator
/// cannot coalesce all subreg operations during allocation.
///
FunctionPass *createLowerSubregsPass();
/// createPostRAScheduler - under development.
FunctionPass *createPostRAScheduler();
/// BranchFolding Pass - 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.
FunctionPass *createBranchFoldingPass(bool DefaultEnableTailMerge);
/// IfConverter Pass - This pass performs machine code if conversion.
FunctionPass *createIfConverterPass();
/// DebugLabelFoldingPass - This pass prunes out redundant debug labels. This
/// allows a debug emitter to determine if the range of two labels is empty,
/// by seeing if the labels map to the same reduced label.
FunctionPass *createDebugLabelFoldingPass();
/// MachineCodeDeletion Pass - This pass deletes all of the machine code for
/// the current function, which should happen after the function has been
/// emitted to a .s file or to memory.
FunctionPass *createMachineCodeDeleter();
/// getRegisterAllocator - This creates an instance of the register allocator
/// for the Sparc.
FunctionPass *getRegisterAllocator(TargetMachine &T);
} // End llvm namespace
#endif