1
0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-24 19:52:54 +01:00
llvm-mirror/include/llvm/Transforms/IPO.h
Chandler Carruth 90665f11d7 [PM] Port the always inliner to the new pass manager in a much more
minimal and boring form than the old pass manager's version.

This pass does the very minimal amount of work necessary to inline
functions declared as always-inline. It doesn't support a wide array of
things that the legacy pass manager did support, but is alse ... about
20 lines of code. So it has that going for it. Notably things this
doesn't support:

- Array alloca merging
  - To support the above, bottom-up inlining with careful history
    tracking and call graph updates
- DCE of the functions that become dead after this inlining.
- Inlining through call instructions with the always_inline attribute.
  Instead, it focuses on inlining functions with that attribute.

The first I've omitted because I'm hoping to just turn it off for the
primary pass manager. If that doesn't pan out, I can add it here but it
will be reasonably expensive to do so.

The second should really be handled by running global-dce after the
inliner. I don't want to re-implement the non-trivial logic necessary to
do comdat-correct DCE of functions. This means the -O0 pipeline will
have to be at least 'always-inline,global-dce', but that seems
reasonable to me. If others are seriously worried about this I'd like to
hear about it and understand why. Again, this is all solveable by
factoring that logic into a utility and calling it here, but I'd like to
wait to do that until there is a clear reason why the existing
pass-based factoring won't work.

The final point is a serious one. I can fairly easily add support for
this, but it seems both costly and a confusing construct for the use
case of the always inliner running at -O0. This attribute can of course
still impact the normal inliner easily (although I find that
a questionable re-use of the same attribute). I've started a discussion
to sort out what semantics we want here and based on that can figure out
if it makes sense ta have this complexity at O0 or not.

One other advantage of this design is that it should be quite a bit
faster due to checking for whether the function is a viable candidate
for inlining exactly once per function instead of doing it for each call
site.

Anyways, hopefully a reasonable starting point for this pass.

Differential Revision: https://reviews.llvm.org/D23299

llvm-svn: 278896
2016-08-17 02:56:20 +00:00

233 lines
9.1 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 <functional>
#include <vector>
namespace llvm {
struct InlineParams;
class StringRef;
class ModuleSummaryIndex;
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();
//===----------------------------------------------------------------------===//
/// This transform is designed to eliminate available external globals
/// (functions or global variables)
///
ModulePass *createEliminateAvailableExternallyPass();
//===----------------------------------------------------------------------===//
/// 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);
//===----------------------------------------------------------------------===//
/// This pass performs iterative function importing from other modules.
Pass *createFunctionImportPass(const ModuleSummaryIndex *Index = nullptr);
//===----------------------------------------------------------------------===//
/// 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);
Pass *createFunctionInliningPass(InlineParams &Params);
//===----------------------------------------------------------------------===//
/// 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.
////
/// Before internalizing a symbol, the callback \p MustPreserveGV is invoked and
/// gives to the client the ability to prevent internalizing specific symbols.
///
/// 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(std::function<bool(const GlobalValue &)> MustPreserveGV);
/// 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();
//===----------------------------------------------------------------------===//
/// createReversePostOrderFunctionAttrsPass - This pass walks SCCs of the call
/// graph in RPO to deduce and propagate function attributes. Currently it
/// only handles synthesizing norecurse attributes.
///
Pass *createReversePostOrderFunctionAttrsPass();
//===----------------------------------------------------------------------===//
/// 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 type metadata and the llvm.type.test intrinsic to
/// bitsets.
ModulePass *createLowerTypeTestsPass();
/// \brief This pass export CFI checks for use by external modules.
ModulePass *createCrossDSOCFIPass();
/// \brief This pass implements whole-program devirtualization using type
/// metadata.
ModulePass *createWholeProgramDevirtPass();
//===----------------------------------------------------------------------===//
// SampleProfilePass - Loads sample profile data from disk and generates
// IR metadata to reflect the profile.
ModulePass *createSampleProfileLoaderPass();
ModulePass *createSampleProfileLoaderPass(StringRef Name);
} // End llvm namespace
#endif