1 //===-- Passes.h - Target independent code generation passes ----*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines interfaces to access the target independent code generation
11 // passes provided by the LLVM backend.
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_CODEGEN_PASSES_H
16 #define LLVM_CODEGEN_PASSES_H
24 // PHIElimination pass - This pass eliminates machine instruction PHI nodes by
25 // inserting copy instructions. This destroys SSA information, but is the
26 // desired input for some register allocators. This pass is "required" by these
27 // register allocator like this: AU.addRequiredID(PHIEliminationID);
29 extern const PassInfo *PHIEliminationID;
31 // TwoAddressInstruction pass - This pass reduces two-address
32 // instructions to use two operands. This destroys SSA information but
33 // it is desired by register allocators.
34 extern const PassInfo *TwoAddressInstructionPassID;
36 /// Creates a register allocator as the user specified on the command
38 FunctionPass *createRegisterAllocator();
40 /// SimpleRegisterAllocation Pass - This pass converts the input machine code
41 /// from SSA form to use explicit registers by spilling every register. Wow,
44 FunctionPass *createSimpleRegisterAllocator();
46 /// LocalRegisterAllocation Pass - This pass register allocates the input code a
47 /// basic block at a time, yielding code better than the simple register
48 /// allocator, but not as good as a global allocator.
50 FunctionPass *createLocalRegisterAllocator();
52 /// LinearScanRegisterAllocation Pass - This pass implements the
53 /// linear scan register allocation algorithm, a global register
56 FunctionPass *createLinearScanRegisterAllocator();
58 /// PrologEpilogCodeInserter Pass - This pass inserts prolog and epilog code,
59 /// and eliminates abstract frame references.
61 FunctionPass *createPrologEpilogCodeInserter();
63 /// getRegisterAllocator - This creates an instance of the register allocator
65 FunctionPass *getRegisterAllocator(TargetMachine &T);
67 } // End llvm namespace