llvm-6502/include/llvm/Transforms/IPO.h
Rafael Espindola 438900938c Optimize linkonce_odr unnamed_addr functions during LTO.
Generalize the API so we can distinguish symbols that are needed just for a DSO
symbol table from those that are used from some native .o.

The symbols that are only wanted for the dso symbol table can be dropped if
llvm can prove every other dso has a copy (linkonce_odr) and the address is not
important (unnamed_addr).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191922 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-03 18:29:09 +00:00

220 lines
8.9 KiB
C++

//===- llvm/Transforms/IPO.h - Interprocedural Transformations --*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This header file defines prototypes for accessor functions that expose passes
// in the IPO transformations library.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_TRANSFORMS_IPO_H
#define LLVM_TRANSFORMS_IPO_H
#include "llvm/ADT/ArrayRef.h"
namespace llvm {
class ModulePass;
class Pass;
class Function;
class BasicBlock;
class GlobalValue;
//===----------------------------------------------------------------------===//
//
// These functions removes symbols from functions and modules. If OnlyDebugInfo
// is true, only debugging information is removed from the module.
//
ModulePass *createStripSymbolsPass(bool OnlyDebugInfo = false);
//===----------------------------------------------------------------------===//
//
// These functions strips symbols from functions and modules.
// Only debugging information is not stripped.
//
ModulePass *createStripNonDebugSymbolsPass();
//===----------------------------------------------------------------------===//
//
// These pass removes llvm.dbg.declare intrinsics.
ModulePass *createStripDebugDeclarePass();
//===----------------------------------------------------------------------===//
//
// These pass removes unused symbols' debug info.
ModulePass *createStripDeadDebugInfoPass();
//===----------------------------------------------------------------------===//
/// createConstantMergePass - This function returns a new pass that merges
/// duplicate global constants together into a single constant that is shared.
/// This is useful because some passes (ie TraceValues) insert a lot of string
/// constants into the program, regardless of whether or not they duplicate an
/// existing string.
///
ModulePass *createConstantMergePass();
//===----------------------------------------------------------------------===//
/// createGlobalOptimizerPass - This function returns a new pass that optimizes
/// non-address taken internal globals.
///
ModulePass *createGlobalOptimizerPass();
//===----------------------------------------------------------------------===//
/// createGlobalDCEPass - This transform is designed to eliminate unreachable
/// internal globals (functions or global variables)
///
ModulePass *createGlobalDCEPass();
//===----------------------------------------------------------------------===//
/// createGVExtractionPass - If deleteFn is true, this pass deletes
/// the specified global values. Otherwise, it deletes as much of the module as
/// possible, except for the global values specified.
///
ModulePass *createGVExtractionPass(std::vector<GlobalValue*>& GVs, bool
deleteFn = false);
//===----------------------------------------------------------------------===//
/// createFunctionInliningPass - Return a new pass object that uses a heuristic
/// to inline direct function calls to small functions.
///
/// The -inline-threshold command line option takes precedence over the
/// threshold given here.
Pass *createFunctionInliningPass();
Pass *createFunctionInliningPass(int Threshold);
//===----------------------------------------------------------------------===//
/// createAlwaysInlinerPass - Return a new pass object that inlines only
/// functions that are marked as "always_inline".
Pass *createAlwaysInlinerPass();
Pass *createAlwaysInlinerPass(bool InsertLifetime);
//===----------------------------------------------------------------------===//
/// createPruneEHPass - Return a new pass object which transforms invoke
/// instructions into calls, if the callee can _not_ unwind the stack.
///
Pass *createPruneEHPass();
//===----------------------------------------------------------------------===//
/// createInternalizePass - This pass loops over all of the functions in the
/// input module, internalizing all globals (functions and variables) it can.
////
/// The symbols in \p ExportList are never internalized.
///
/// The symbol in DSOList are internalized if it is safe to drop them from
/// the symbol table.
///
/// For example of the difference, consider a dynamic library being built from
/// two translation units. The first one compiled to a native object
/// (ELF/MachO/COFF) and second one compiled to IL. Translation unit A has a
/// copy of linkonce_odr unnamed_addr function F. The translation unit B has a
/// copy of the linkonce_odr unnamed_addr functions F and G.
///
/// Assume the linker decides to keep the copy of F in B. This means that LLVM
/// must produce F in the object file it passes to the linker, otherwise we
/// will have an undefined reference. For G the situation is different. The
/// linker puts the function in the DSOList, since it is only wanted for the
/// symbol table. With this information internalize can now reason that since
/// the function is a linkonce_odr and its address is not important, it can be
/// omitted. Any other shared library needing this function will have a copy of
/// it.
///
/// Note that commandline options that are used with the above function are not
/// used now!
ModulePass *createInternalizePass(ArrayRef<const char *> ExportList,
ArrayRef<const char *> DSOList);
/// createInternalizePass - Same as above, but with an empty exportList.
ModulePass *createInternalizePass();
//===----------------------------------------------------------------------===//
/// createDeadArgEliminationPass - This pass removes arguments from functions
/// which are not used by the body of the function.
///
ModulePass *createDeadArgEliminationPass();
/// DeadArgHacking pass - Same as DAE, but delete arguments of external
/// functions as well. This is definitely not safe, and should only be used by
/// bugpoint.
ModulePass *createDeadArgHackingPass();
//===----------------------------------------------------------------------===//
/// createArgumentPromotionPass - This pass promotes "by reference" arguments to
/// be passed by value if the number of elements passed is smaller or
/// equal to maxElements (maxElements == 0 means always promote).
///
Pass *createArgumentPromotionPass(unsigned maxElements = 3);
//===----------------------------------------------------------------------===//
/// createIPConstantPropagationPass - This pass propagates constants from call
/// sites into the bodies of functions.
///
ModulePass *createIPConstantPropagationPass();
//===----------------------------------------------------------------------===//
/// createIPSCCPPass - This pass propagates constants from call sites into the
/// bodies of functions, and keeps track of whether basic blocks are executable
/// in the process.
///
ModulePass *createIPSCCPPass();
//===----------------------------------------------------------------------===//
//
/// createLoopExtractorPass - This pass extracts all natural loops from the
/// program into a function if it can.
///
Pass *createLoopExtractorPass();
/// createSingleLoopExtractorPass - This pass extracts one natural loop from the
/// program into a function if it can. This is used by bugpoint.
///
Pass *createSingleLoopExtractorPass();
/// createBlockExtractorPass - This pass extracts all blocks (except those
/// specified in the argument list) from the functions in the module.
///
ModulePass *createBlockExtractorPass();
/// createStripDeadPrototypesPass - This pass removes any function declarations
/// (prototypes) that are not used.
ModulePass *createStripDeadPrototypesPass();
//===----------------------------------------------------------------------===//
/// createFunctionAttrsPass - This pass discovers functions that do not access
/// memory, or only read memory, and gives them the readnone/readonly attribute.
/// It also discovers function arguments that are not captured by the function
/// and marks them with the nocapture attribute.
///
Pass *createFunctionAttrsPass();
//===----------------------------------------------------------------------===//
/// createMergeFunctionsPass - This pass discovers identical functions and
/// collapses them.
///
ModulePass *createMergeFunctionsPass();
//===----------------------------------------------------------------------===//
/// createPartialInliningPass - This pass inlines parts of functions.
///
ModulePass *createPartialInliningPass();
//===----------------------------------------------------------------------===//
// createMetaRenamerPass - Rename everything with metasyntatic names.
//
ModulePass *createMetaRenamerPass();
//===----------------------------------------------------------------------===//
/// createBarrierNoopPass - This pass is purely a module pass barrier in a pass
/// manager.
ModulePass *createBarrierNoopPass();
} // End llvm namespace
#endif