llvm/lib/Passes/PassBuilder.cpp
Chandler Carruth f7ae2f50a0 [PM] Wire up optimization levels and default pipeline construction APIs
in the PassBuilder.

These are really just stubs for now, but they give a nice API surface
that Clang or other tools can start learning about and enabling for
experimentation.

I've also wired up parsing various synthetic module pass names to
generate these set pipelines. This allows the pipelines to be combined
with other passes and have their order controlled, with clear separation
between the *kind* of canned pipeline, and the *level* of optimization
to be used within that canned pipeline.

The most interesting part of this patch is almost certainly the spec for
the different optimization levels. I don't think we can ever have hard
and fast rules that would make it easy to determine whether a particular
optimization makes sense at a particular level -- it will always be in
large part a judgement call. But hopefully this will outline the
expected rationale that should be used, and the direction that the
pipelines should be taken. Much of this was based on a long llvm-dev
discussion I started years ago to try and crystalize the intent behind
these pipelines, and now, at long long last I'm returning to the task of
actually writing it down somewhere that we can cite and try to be
consistent with.

Differential Revision: http://reviews.llvm.org/D12826

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262196 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-28 22:16:03 +00:00

630 lines
25 KiB
C++

//===- Parsing, selection, and construction of pass pipelines -------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
/// \file
///
/// This file provides the implementation of the PassBuilder based on our
/// static pass registry as well as related functionality. It also provides
/// helpers to aid in analyzing, debugging, and testing passes and pass
/// pipelines.
///
//===----------------------------------------------------------------------===//
#include "llvm/Passes/PassBuilder.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/AliasAnalysisEvaluator.h"
#include "llvm/Analysis/AssumptionCache.h"
#include "llvm/Analysis/BasicAliasAnalysis.h"
#include "llvm/Analysis/CFLAliasAnalysis.h"
#include "llvm/Analysis/CGSCCPassManager.h"
#include "llvm/Analysis/DominanceFrontier.h"
#include "llvm/Analysis/LazyCallGraph.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/PostDominators.h"
#include "llvm/Analysis/RegionInfo.h"
#include "llvm/Analysis/ScalarEvolution.h"
#include "llvm/Analysis/ScalarEvolutionAliasAnalysis.h"
#include "llvm/Analysis/ScopedNoAliasAA.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/Analysis/TypeBasedAliasAnalysis.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/IRPrintingPasses.h"
#include "llvm/IR/PassManager.h"
#include "llvm/IR/Verifier.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/Regex.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Transforms/IPO/ForceFunctionAttrs.h"
#include "llvm/Transforms/IPO/FunctionAttrs.h"
#include "llvm/Transforms/IPO/InferFunctionAttrs.h"
#include "llvm/Transforms/IPO/StripDeadPrototypes.h"
#include "llvm/Transforms/InstCombine/InstCombine.h"
#include "llvm/Transforms/Scalar/ADCE.h"
#include "llvm/Transforms/Scalar/EarlyCSE.h"
#include "llvm/Transforms/Scalar/LowerExpectIntrinsic.h"
#include "llvm/Transforms/Scalar/SROA.h"
#include "llvm/Transforms/Scalar/SimplifyCFG.h"
#include <type_traits>
using namespace llvm;
static Regex DefaultAliasRegex("^(default|lto-pre-link|lto)<(O[0123sz])>$");
namespace {
/// \brief No-op module pass which does nothing.
struct NoOpModulePass {
PreservedAnalyses run(Module &M) { return PreservedAnalyses::all(); }
static StringRef name() { return "NoOpModulePass"; }
};
/// \brief No-op module analysis.
struct NoOpModuleAnalysis : AnalysisBase<NoOpModuleAnalysis> {
struct Result {};
Result run(Module &) { return Result(); }
static StringRef name() { return "NoOpModuleAnalysis"; }
};
/// \brief No-op CGSCC pass which does nothing.
struct NoOpCGSCCPass {
PreservedAnalyses run(LazyCallGraph::SCC &C) {
return PreservedAnalyses::all();
}
static StringRef name() { return "NoOpCGSCCPass"; }
};
/// \brief No-op CGSCC analysis.
struct NoOpCGSCCAnalysis : AnalysisBase<NoOpCGSCCAnalysis> {
struct Result {};
Result run(LazyCallGraph::SCC &) { return Result(); }
static StringRef name() { return "NoOpCGSCCAnalysis"; }
};
/// \brief No-op function pass which does nothing.
struct NoOpFunctionPass {
PreservedAnalyses run(Function &F) { return PreservedAnalyses::all(); }
static StringRef name() { return "NoOpFunctionPass"; }
};
/// \brief No-op function analysis.
struct NoOpFunctionAnalysis : AnalysisBase<NoOpFunctionAnalysis> {
struct Result {};
Result run(Function &) { return Result(); }
static StringRef name() { return "NoOpFunctionAnalysis"; }
};
/// \brief No-op loop pass which does nothing.
struct NoOpLoopPass {
PreservedAnalyses run(Loop &L) { return PreservedAnalyses::all(); }
static StringRef name() { return "NoOpLoopPass"; }
};
/// \brief No-op loop analysis.
struct NoOpLoopAnalysis : AnalysisBase<NoOpLoopAnalysis> {
struct Result {};
Result run(Loop &) { return Result(); }
static StringRef name() { return "NoOpLoopAnalysis"; }
};
} // End anonymous namespace.
void PassBuilder::registerModuleAnalyses(ModuleAnalysisManager &MAM) {
#define MODULE_ANALYSIS(NAME, CREATE_PASS) \
MAM.registerPass([&] { return CREATE_PASS; });
#include "PassRegistry.def"
}
void PassBuilder::registerCGSCCAnalyses(CGSCCAnalysisManager &CGAM) {
#define CGSCC_ANALYSIS(NAME, CREATE_PASS) \
CGAM.registerPass([&] { return CREATE_PASS; });
#include "PassRegistry.def"
}
void PassBuilder::registerFunctionAnalyses(FunctionAnalysisManager &FAM) {
#define FUNCTION_ANALYSIS(NAME, CREATE_PASS) \
FAM.registerPass([&] { return CREATE_PASS; });
#include "PassRegistry.def"
}
void PassBuilder::registerLoopAnalyses(LoopAnalysisManager &LAM) {
#define LOOP_ANALYSIS(NAME, CREATE_PASS) \
LAM.registerPass([&] { return CREATE_PASS; });
#include "PassRegistry.def"
}
void PassBuilder::addPerModuleDefaultPipeline(ModulePassManager &MPM,
OptimizationLevel Level,
bool DebugLogging) {
// FIXME: Finish fleshing this out to match the legacy pipelines.
FunctionPassManager EarlyFPM(DebugLogging);
EarlyFPM.addPass(SimplifyCFGPass());
EarlyFPM.addPass(SROA());
EarlyFPM.addPass(EarlyCSEPass());
EarlyFPM.addPass(LowerExpectIntrinsicPass());
MPM.addPass(createModuleToFunctionPassAdaptor(std::move(EarlyFPM)));
}
void PassBuilder::addLTOPreLinkDefaultPipeline(ModulePassManager &MPM,
OptimizationLevel Level,
bool DebugLogging) {
// FIXME: We should use a customized pre-link pipeline!
addPerModuleDefaultPipeline(MPM, Level, DebugLogging);
}
void PassBuilder::addLTODefaultPipeline(ModulePassManager &MPM,
OptimizationLevel Level,
bool DebugLogging) {
// FIXME: Finish fleshing this out to match the legacy LTO pipelines.
FunctionPassManager LateFPM(DebugLogging);
LateFPM.addPass(InstCombinePass());
LateFPM.addPass(SimplifyCFGPass());
MPM.addPass(createModuleToFunctionPassAdaptor(std::move(LateFPM)));
}
#ifndef NDEBUG
static bool isModulePassName(StringRef Name) {
// Manually handle aliases for pre-configured pipeline fragments.
if (Name.startswith("default") || Name.startswith("lto"))
return DefaultAliasRegex.match(Name);
#define MODULE_PASS(NAME, CREATE_PASS) if (Name == NAME) return true;
#define MODULE_ANALYSIS(NAME, CREATE_PASS) \
if (Name == "require<" NAME ">" || Name == "invalidate<" NAME ">") \
return true;
#include "PassRegistry.def"
return false;
}
#endif
static bool isCGSCCPassName(StringRef Name) {
#define CGSCC_PASS(NAME, CREATE_PASS) if (Name == NAME) return true;
#define CGSCC_ANALYSIS(NAME, CREATE_PASS) \
if (Name == "require<" NAME ">" || Name == "invalidate<" NAME ">") \
return true;
#include "PassRegistry.def"
return false;
}
static bool isFunctionPassName(StringRef Name) {
#define FUNCTION_PASS(NAME, CREATE_PASS) if (Name == NAME) return true;
#define FUNCTION_ANALYSIS(NAME, CREATE_PASS) \
if (Name == "require<" NAME ">" || Name == "invalidate<" NAME ">") \
return true;
#include "PassRegistry.def"
return false;
}
static bool isLoopPassName(StringRef Name) {
#define LOOP_PASS(NAME, CREATE_PASS) if (Name == NAME) return true;
#define LOOP_ANALYSIS(NAME, CREATE_PASS) \
if (Name == "require<" NAME ">" || Name == "invalidate<" NAME ">") \
return true;
#include "PassRegistry.def"
return false;
}
bool PassBuilder::parseModulePassName(ModulePassManager &MPM, StringRef Name,
bool DebugLogging) {
// Manually handle aliases for pre-configured pipeline fragments.
if (Name.startswith("default") || Name.startswith("lto")) {
SmallVector<StringRef, 3> Matches;
if (!DefaultAliasRegex.match(Name, &Matches))
return false;
assert(Matches.size() == 3 && "Must capture two matched strings!");
auto L = StringSwitch<OptimizationLevel>(Matches[2])
.Case("O0", O0)
.Case("O1", O1)
.Case("O2", O2)
.Case("O3", O3)
.Case("Os", Os)
.Case("Oz", Oz);
if (Matches[1] == "default") {
addPerModuleDefaultPipeline(MPM, L, DebugLogging);
} else if (Matches[1] == "lto-pre-link") {
addLTOPreLinkDefaultPipeline(MPM, L, DebugLogging);
} else {
assert(Matches[1] == "lto" && "Not one of the matched options!");
addLTODefaultPipeline(MPM, L, DebugLogging);
}
return true;
}
#define MODULE_PASS(NAME, CREATE_PASS) \
if (Name == NAME) { \
MPM.addPass(CREATE_PASS); \
return true; \
}
#define MODULE_ANALYSIS(NAME, CREATE_PASS) \
if (Name == "require<" NAME ">") { \
MPM.addPass(RequireAnalysisPass< \
std::remove_reference<decltype(CREATE_PASS)>::type>()); \
return true; \
} \
if (Name == "invalidate<" NAME ">") { \
MPM.addPass(InvalidateAnalysisPass< \
std::remove_reference<decltype(CREATE_PASS)>::type>()); \
return true; \
}
#include "PassRegistry.def"
return false;
}
bool PassBuilder::parseCGSCCPassName(CGSCCPassManager &CGPM, StringRef Name) {
#define CGSCC_PASS(NAME, CREATE_PASS) \
if (Name == NAME) { \
CGPM.addPass(CREATE_PASS); \
return true; \
}
#define CGSCC_ANALYSIS(NAME, CREATE_PASS) \
if (Name == "require<" NAME ">") { \
CGPM.addPass(RequireAnalysisPass< \
std::remove_reference<decltype(CREATE_PASS)>::type>()); \
return true; \
} \
if (Name == "invalidate<" NAME ">") { \
CGPM.addPass(InvalidateAnalysisPass< \
std::remove_reference<decltype(CREATE_PASS)>::type>()); \
return true; \
}
#include "PassRegistry.def"
return false;
}
bool PassBuilder::parseFunctionPassName(FunctionPassManager &FPM,
StringRef Name) {
#define FUNCTION_PASS(NAME, CREATE_PASS) \
if (Name == NAME) { \
FPM.addPass(CREATE_PASS); \
return true; \
}
#define FUNCTION_ANALYSIS(NAME, CREATE_PASS) \
if (Name == "require<" NAME ">") { \
FPM.addPass(RequireAnalysisPass< \
std::remove_reference<decltype(CREATE_PASS)>::type>()); \
return true; \
} \
if (Name == "invalidate<" NAME ">") { \
FPM.addPass(InvalidateAnalysisPass< \
std::remove_reference<decltype(CREATE_PASS)>::type>()); \
return true; \
}
#include "PassRegistry.def"
return false;
}
bool PassBuilder::parseLoopPassName(LoopPassManager &FPM,
StringRef Name) {
#define LOOP_PASS(NAME, CREATE_PASS) \
if (Name == NAME) { \
FPM.addPass(CREATE_PASS); \
return true; \
}
#define LOOP_ANALYSIS(NAME, CREATE_PASS) \
if (Name == "require<" NAME ">") { \
FPM.addPass(RequireAnalysisPass< \
std::remove_reference<decltype(CREATE_PASS)>::type>()); \
return true; \
} \
if (Name == "invalidate<" NAME ">") { \
FPM.addPass(InvalidateAnalysisPass< \
std::remove_reference<decltype(CREATE_PASS)>::type>()); \
return true; \
}
#include "PassRegistry.def"
return false;
}
bool PassBuilder::parseAAPassName(AAManager &AA, StringRef Name) {
#define FUNCTION_ALIAS_ANALYSIS(NAME, CREATE_PASS) \
if (Name == NAME) { \
AA.registerFunctionAnalysis< \
std::remove_reference<decltype(CREATE_PASS)>::type>(); \
return true; \
}
#include "PassRegistry.def"
return false;
}
bool PassBuilder::parseLoopPassPipeline(LoopPassManager &LPM,
StringRef &PipelineText,
bool VerifyEachPass,
bool DebugLogging) {
for (;;) {
// Parse nested pass managers by recursing.
if (PipelineText.startswith("loop(")) {
LoopPassManager NestedLPM(DebugLogging);
// Parse the inner pipeline inte the nested manager.
PipelineText = PipelineText.substr(strlen("loop("));
if (!parseLoopPassPipeline(NestedLPM, PipelineText, VerifyEachPass,
DebugLogging) ||
PipelineText.empty())
return false;
assert(PipelineText[0] == ')');
PipelineText = PipelineText.substr(1);
// Add the nested pass manager with the appropriate adaptor.
LPM.addPass(std::move(NestedLPM));
} else {
// Otherwise try to parse a pass name.
size_t End = PipelineText.find_first_of(",)");
if (!parseLoopPassName(LPM, PipelineText.substr(0, End)))
return false;
// TODO: Ideally, we would run a LoopVerifierPass() here in the
// VerifyEachPass case, but we don't have such a verifier yet.
PipelineText = PipelineText.substr(End);
}
if (PipelineText.empty() || PipelineText[0] == ')')
return true;
assert(PipelineText[0] == ',');
PipelineText = PipelineText.substr(1);
}
}
bool PassBuilder::parseFunctionPassPipeline(FunctionPassManager &FPM,
StringRef &PipelineText,
bool VerifyEachPass,
bool DebugLogging) {
for (;;) {
// Parse nested pass managers by recursing.
if (PipelineText.startswith("function(")) {
FunctionPassManager NestedFPM(DebugLogging);
// Parse the inner pipeline inte the nested manager.
PipelineText = PipelineText.substr(strlen("function("));
if (!parseFunctionPassPipeline(NestedFPM, PipelineText, VerifyEachPass,
DebugLogging) ||
PipelineText.empty())
return false;
assert(PipelineText[0] == ')');
PipelineText = PipelineText.substr(1);
// Add the nested pass manager with the appropriate adaptor.
FPM.addPass(std::move(NestedFPM));
} else if (PipelineText.startswith("loop(")) {
LoopPassManager NestedLPM(DebugLogging);
// Parse the inner pipeline inte the nested manager.
PipelineText = PipelineText.substr(strlen("loop("));
if (!parseLoopPassPipeline(NestedLPM, PipelineText, VerifyEachPass,
DebugLogging) ||
PipelineText.empty())
return false;
assert(PipelineText[0] == ')');
PipelineText = PipelineText.substr(1);
// Add the nested pass manager with the appropriate adaptor.
FPM.addPass(createFunctionToLoopPassAdaptor(std::move(NestedLPM)));
} else {
// Otherwise try to parse a pass name.
size_t End = PipelineText.find_first_of(",)");
if (!parseFunctionPassName(FPM, PipelineText.substr(0, End)))
return false;
if (VerifyEachPass)
FPM.addPass(VerifierPass());
PipelineText = PipelineText.substr(End);
}
if (PipelineText.empty() || PipelineText[0] == ')')
return true;
assert(PipelineText[0] == ',');
PipelineText = PipelineText.substr(1);
}
}
bool PassBuilder::parseCGSCCPassPipeline(CGSCCPassManager &CGPM,
StringRef &PipelineText,
bool VerifyEachPass,
bool DebugLogging) {
for (;;) {
// Parse nested pass managers by recursing.
if (PipelineText.startswith("cgscc(")) {
CGSCCPassManager NestedCGPM(DebugLogging);
// Parse the inner pipeline into the nested manager.
PipelineText = PipelineText.substr(strlen("cgscc("));
if (!parseCGSCCPassPipeline(NestedCGPM, PipelineText, VerifyEachPass,
DebugLogging) ||
PipelineText.empty())
return false;
assert(PipelineText[0] == ')');
PipelineText = PipelineText.substr(1);
// Add the nested pass manager with the appropriate adaptor.
CGPM.addPass(std::move(NestedCGPM));
} else if (PipelineText.startswith("function(")) {
FunctionPassManager NestedFPM(DebugLogging);
// Parse the inner pipeline inte the nested manager.
PipelineText = PipelineText.substr(strlen("function("));
if (!parseFunctionPassPipeline(NestedFPM, PipelineText, VerifyEachPass,
DebugLogging) ||
PipelineText.empty())
return false;
assert(PipelineText[0] == ')');
PipelineText = PipelineText.substr(1);
// Add the nested pass manager with the appropriate adaptor.
CGPM.addPass(createCGSCCToFunctionPassAdaptor(std::move(NestedFPM)));
} else {
// Otherwise try to parse a pass name.
size_t End = PipelineText.find_first_of(",)");
if (!parseCGSCCPassName(CGPM, PipelineText.substr(0, End)))
return false;
// FIXME: No verifier support for CGSCC passes!
PipelineText = PipelineText.substr(End);
}
if (PipelineText.empty() || PipelineText[0] == ')')
return true;
assert(PipelineText[0] == ',');
PipelineText = PipelineText.substr(1);
}
}
bool PassBuilder::parseModulePassPipeline(ModulePassManager &MPM,
StringRef &PipelineText,
bool VerifyEachPass,
bool DebugLogging) {
for (;;) {
// Parse nested pass managers by recursing.
if (PipelineText.startswith("module(")) {
ModulePassManager NestedMPM(DebugLogging);
// Parse the inner pipeline into the nested manager.
PipelineText = PipelineText.substr(strlen("module("));
if (!parseModulePassPipeline(NestedMPM, PipelineText, VerifyEachPass,
DebugLogging) ||
PipelineText.empty())
return false;
assert(PipelineText[0] == ')');
PipelineText = PipelineText.substr(1);
// Now add the nested manager as a module pass.
MPM.addPass(std::move(NestedMPM));
} else if (PipelineText.startswith("cgscc(")) {
CGSCCPassManager NestedCGPM(DebugLogging);
// Parse the inner pipeline inte the nested manager.
PipelineText = PipelineText.substr(strlen("cgscc("));
if (!parseCGSCCPassPipeline(NestedCGPM, PipelineText, VerifyEachPass,
DebugLogging) ||
PipelineText.empty())
return false;
assert(PipelineText[0] == ')');
PipelineText = PipelineText.substr(1);
// Add the nested pass manager with the appropriate adaptor.
MPM.addPass(
createModuleToPostOrderCGSCCPassAdaptor(std::move(NestedCGPM)));
} else if (PipelineText.startswith("function(")) {
FunctionPassManager NestedFPM(DebugLogging);
// Parse the inner pipeline inte the nested manager.
PipelineText = PipelineText.substr(strlen("function("));
if (!parseFunctionPassPipeline(NestedFPM, PipelineText, VerifyEachPass,
DebugLogging) ||
PipelineText.empty())
return false;
assert(PipelineText[0] == ')');
PipelineText = PipelineText.substr(1);
// Add the nested pass manager with the appropriate adaptor.
MPM.addPass(createModuleToFunctionPassAdaptor(std::move(NestedFPM)));
} else {
// Otherwise try to parse a pass name.
size_t End = PipelineText.find_first_of(",)");
if (!parseModulePassName(MPM, PipelineText.substr(0, End), DebugLogging))
return false;
if (VerifyEachPass)
MPM.addPass(VerifierPass());
PipelineText = PipelineText.substr(End);
}
if (PipelineText.empty() || PipelineText[0] == ')')
return true;
assert(PipelineText[0] == ',');
PipelineText = PipelineText.substr(1);
}
}
// Primary pass pipeline description parsing routine.
// FIXME: Should this routine accept a TargetMachine or require the caller to
// pre-populate the analysis managers with target-specific stuff?
bool PassBuilder::parsePassPipeline(ModulePassManager &MPM,
StringRef PipelineText, bool VerifyEachPass,
bool DebugLogging) {
// By default, try to parse the pipeline as-if it were within an implicit
// 'module(...)' pass pipeline. If this will parse at all, it needs to
// consume the entire string.
if (parseModulePassPipeline(MPM, PipelineText, VerifyEachPass, DebugLogging))
return PipelineText.empty();
// This isn't parsable as a module pipeline, look for the end of a pass name
// and directly drop down to that layer.
StringRef FirstName =
PipelineText.substr(0, PipelineText.find_first_of(",)"));
assert(!isModulePassName(FirstName) &&
"Already handled all module pipeline options.");
// If this looks like a CGSCC pass, parse the whole thing as a CGSCC
// pipeline.
if (PipelineText.startswith("cgscc(") || isCGSCCPassName(FirstName)) {
CGSCCPassManager CGPM(DebugLogging);
if (!parseCGSCCPassPipeline(CGPM, PipelineText, VerifyEachPass,
DebugLogging) ||
!PipelineText.empty())
return false;
MPM.addPass(createModuleToPostOrderCGSCCPassAdaptor(std::move(CGPM)));
return true;
}
// Similarly, if this looks like a Function pass, parse the whole thing as
// a Function pipelien.
if (PipelineText.startswith("function(") || isFunctionPassName(FirstName)) {
FunctionPassManager FPM(DebugLogging);
if (!parseFunctionPassPipeline(FPM, PipelineText, VerifyEachPass,
DebugLogging) ||
!PipelineText.empty())
return false;
MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
return true;
}
// If this looks like a Loop pass, parse the whole thing as a Loop pipeline.
if (PipelineText.startswith("loop(") || isLoopPassName(FirstName)) {
LoopPassManager LPM(DebugLogging);
if (!parseLoopPassPipeline(LPM, PipelineText, VerifyEachPass,
DebugLogging) ||
!PipelineText.empty())
return false;
FunctionPassManager FPM(DebugLogging);
FPM.addPass(createFunctionToLoopPassAdaptor(std::move(LPM)));
MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
return true;
}
return false;
}
bool PassBuilder::parseAAPipeline(AAManager &AA, StringRef PipelineText) {
while (!PipelineText.empty()) {
StringRef Name;
std::tie(Name, PipelineText) = PipelineText.split(',');
if (!parseAAPassName(AA, Name))
return false;
}
return true;
}