llvm-6502/include/llvm/Transforms/IPO.h
Peter Collingbourne 5a81e14385 Introduce bitset metadata format and bitset lowering pass.
This patch introduces a new mechanism that allows IR modules to co-operatively
build pointer sets corresponding to addresses within a given set of
globals. One particular use case for this is to allow a C++ program to
efficiently verify (at each call site) that a vtable pointer is in the set
of valid vtable pointers for the class or its derived classes. One way of
doing this is for a toolchain component to build, for each class, a bit set
that maps to the memory region allocated for the vtables, such that each 1
bit in the bit set maps to a valid vtable for that class, and lay out the
vtables next to each other, to minimize the total size of the bit sets.

The patch introduces a metadata format for representing pointer sets, an
'@llvm.bitset.test' intrinsic and an LTO lowering pass that lays out the globals
and builds the bitsets, and documents the new feature.

Differential Revision: http://reviews.llvm.org/D7288

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230054 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-20 20:30:47 +00:00

209 lines
8.2 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 Threshold can be passed directly, or asked to be computed from the
/// given optimization and size optimization arguments.
///
/// The -inline-threshold command line option takes precedence over the
/// threshold given here.
Pass *createFunctionInliningPass();
Pass *createFunctionInliningPass(int Threshold);
Pass *createFunctionInliningPass(unsigned OptLevel, unsigned SizeOptLevel);
//===----------------------------------------------------------------------===//
/// 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.
///
/// Note that commandline options that are used with the above function are not
/// used now!
ModulePass *createInternalizePass(ArrayRef<const char *> ExportList);
/// 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();
/// \brief This pass lowers bitset metadata and the llvm.bitset.test intrinsic
/// to bitsets.
ModulePass *createLowerBitSetsPass();
} // End llvm namespace
#endif