forked from OSchip/llvm-project
2536 lines
91 KiB
C++
2536 lines
91 KiB
C++
//===- Attributor.cpp - Module-wide attribute deduction -------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements an interprocedural pass that deduces and/or propagates
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// attributes. This is done in an abstract interpretation style fixpoint
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// iteration. See the Attributor.h file comment and the class descriptions in
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// that file for more information.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/Transforms/IPO/Attributor.h"
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#include "llvm/ADT/GraphTraits.h"
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#include "llvm/ADT/PointerIntPair.h"
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#include "llvm/ADT/Statistic.h"
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#include "llvm/ADT/TinyPtrVector.h"
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#include "llvm/Analysis/InlineCost.h"
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#include "llvm/Analysis/LazyValueInfo.h"
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#include "llvm/Analysis/MemorySSAUpdater.h"
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#include "llvm/Analysis/MustExecute.h"
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#include "llvm/Analysis/ValueTracking.h"
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#include "llvm/IR/GlobalValue.h"
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#include "llvm/IR/IRBuilder.h"
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#include "llvm/IR/NoFolder.h"
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#include "llvm/IR/Verifier.h"
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#include "llvm/InitializePasses.h"
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#include "llvm/Support/Casting.h"
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#include "llvm/Support/CommandLine.h"
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#include "llvm/Support/Debug.h"
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#include "llvm/Support/FileSystem.h"
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#include "llvm/Support/GraphWriter.h"
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#include "llvm/Support/raw_ostream.h"
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#include "llvm/Transforms/Utils/BasicBlockUtils.h"
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#include "llvm/Transforms/Utils/Cloning.h"
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#include "llvm/Transforms/Utils/Local.h"
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#include <cassert>
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#include <string>
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using namespace llvm;
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#define DEBUG_TYPE "attributor"
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STATISTIC(NumFnDeleted, "Number of function deleted");
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STATISTIC(NumFnWithExactDefinition,
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"Number of functions with exact definitions");
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STATISTIC(NumFnWithoutExactDefinition,
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"Number of functions without exact definitions");
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STATISTIC(NumFnShallowWrappersCreated, "Number of shallow wrappers created");
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STATISTIC(NumAttributesTimedOut,
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"Number of abstract attributes timed out before fixpoint");
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STATISTIC(NumAttributesValidFixpoint,
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"Number of abstract attributes in a valid fixpoint state");
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STATISTIC(NumAttributesManifested,
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"Number of abstract attributes manifested in IR");
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STATISTIC(NumAttributesFixedDueToRequiredDependences,
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"Number of abstract attributes fixed due to required dependences");
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// TODO: Determine a good default value.
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//
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// In the LLVM-TS and SPEC2006, 32 seems to not induce compile time overheads
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// (when run with the first 5 abstract attributes). The results also indicate
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// that we never reach 32 iterations but always find a fixpoint sooner.
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//
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// This will become more evolved once we perform two interleaved fixpoint
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// iterations: bottom-up and top-down.
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static cl::opt<unsigned>
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MaxFixpointIterations("attributor-max-iterations", cl::Hidden,
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cl::desc("Maximal number of fixpoint iterations."),
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cl::init(32));
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static cl::opt<unsigned, true> MaxInitializationChainLengthX(
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"attributor-max-initialization-chain-length", cl::Hidden,
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cl::desc(
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"Maximal number of chained initializations (to avoid stack overflows)"),
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cl::location(MaxInitializationChainLength), cl::init(1024));
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unsigned llvm::MaxInitializationChainLength;
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static cl::opt<bool> VerifyMaxFixpointIterations(
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"attributor-max-iterations-verify", cl::Hidden,
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cl::desc("Verify that max-iterations is a tight bound for a fixpoint"),
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cl::init(false));
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static cl::opt<bool> AnnotateDeclarationCallSites(
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"attributor-annotate-decl-cs", cl::Hidden,
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cl::desc("Annotate call sites of function declarations."), cl::init(false));
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static cl::opt<bool> EnableHeapToStack("enable-heap-to-stack-conversion",
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cl::init(true), cl::Hidden);
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static cl::opt<bool>
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AllowShallowWrappers("attributor-allow-shallow-wrappers", cl::Hidden,
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cl::desc("Allow the Attributor to create shallow "
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"wrappers for non-exact definitions."),
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cl::init(false));
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static cl::opt<bool>
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AllowDeepWrapper("attributor-allow-deep-wrappers", cl::Hidden,
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cl::desc("Allow the Attributor to use IP information "
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"derived from non-exact functions via cloning"),
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cl::init(false));
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// These options can only used for debug builds.
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#ifndef NDEBUG
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static cl::list<std::string>
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SeedAllowList("attributor-seed-allow-list", cl::Hidden,
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cl::desc("Comma seperated list of attribute names that are "
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"allowed to be seeded."),
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cl::ZeroOrMore, cl::CommaSeparated);
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static cl::list<std::string> FunctionSeedAllowList(
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"attributor-function-seed-allow-list", cl::Hidden,
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cl::desc("Comma seperated list of function names that are "
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"allowed to be seeded."),
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cl::ZeroOrMore, cl::CommaSeparated);
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#endif
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static cl::opt<bool>
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DumpDepGraph("attributor-dump-dep-graph", cl::Hidden,
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cl::desc("Dump the dependency graph to dot files."),
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cl::init(false));
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static cl::opt<std::string> DepGraphDotFileNamePrefix(
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"attributor-depgraph-dot-filename-prefix", cl::Hidden,
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cl::desc("The prefix used for the CallGraph dot file names."));
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static cl::opt<bool> ViewDepGraph("attributor-view-dep-graph", cl::Hidden,
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cl::desc("View the dependency graph."),
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cl::init(false));
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static cl::opt<bool> PrintDependencies("attributor-print-dep", cl::Hidden,
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cl::desc("Print attribute dependencies"),
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cl::init(false));
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/// Logic operators for the change status enum class.
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///
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///{
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ChangeStatus llvm::operator|(ChangeStatus L, ChangeStatus R) {
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return L == ChangeStatus::CHANGED ? L : R;
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}
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ChangeStatus llvm::operator&(ChangeStatus L, ChangeStatus R) {
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return L == ChangeStatus::UNCHANGED ? L : R;
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}
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///}
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/// Return true if \p New is equal or worse than \p Old.
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static bool isEqualOrWorse(const Attribute &New, const Attribute &Old) {
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if (!Old.isIntAttribute())
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return true;
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return Old.getValueAsInt() >= New.getValueAsInt();
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}
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/// Return true if the information provided by \p Attr was added to the
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/// attribute list \p Attrs. This is only the case if it was not already present
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/// in \p Attrs at the position describe by \p PK and \p AttrIdx.
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static bool addIfNotExistent(LLVMContext &Ctx, const Attribute &Attr,
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AttributeList &Attrs, int AttrIdx) {
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if (Attr.isEnumAttribute()) {
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Attribute::AttrKind Kind = Attr.getKindAsEnum();
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if (Attrs.hasAttribute(AttrIdx, Kind))
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if (isEqualOrWorse(Attr, Attrs.getAttribute(AttrIdx, Kind)))
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return false;
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Attrs = Attrs.addAttribute(Ctx, AttrIdx, Attr);
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return true;
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}
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if (Attr.isStringAttribute()) {
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StringRef Kind = Attr.getKindAsString();
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if (Attrs.hasAttribute(AttrIdx, Kind))
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if (isEqualOrWorse(Attr, Attrs.getAttribute(AttrIdx, Kind)))
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return false;
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Attrs = Attrs.addAttribute(Ctx, AttrIdx, Attr);
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return true;
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}
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if (Attr.isIntAttribute()) {
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Attribute::AttrKind Kind = Attr.getKindAsEnum();
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if (Attrs.hasAttribute(AttrIdx, Kind))
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if (isEqualOrWorse(Attr, Attrs.getAttribute(AttrIdx, Kind)))
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return false;
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Attrs = Attrs.removeAttribute(Ctx, AttrIdx, Kind);
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Attrs = Attrs.addAttribute(Ctx, AttrIdx, Attr);
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return true;
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}
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llvm_unreachable("Expected enum or string attribute!");
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}
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Argument *IRPosition::getAssociatedArgument() const {
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if (getPositionKind() == IRP_ARGUMENT)
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return cast<Argument>(&getAnchorValue());
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// Not an Argument and no argument number means this is not a call site
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// argument, thus we cannot find a callback argument to return.
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int ArgNo = getCallSiteArgNo();
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if (ArgNo < 0)
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return nullptr;
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// Use abstract call sites to make the connection between the call site
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// values and the ones in callbacks. If a callback was found that makes use
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// of the underlying call site operand, we want the corresponding callback
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// callee argument and not the direct callee argument.
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Optional<Argument *> CBCandidateArg;
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SmallVector<const Use *, 4> CallbackUses;
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const auto &CB = cast<CallBase>(getAnchorValue());
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AbstractCallSite::getCallbackUses(CB, CallbackUses);
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for (const Use *U : CallbackUses) {
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AbstractCallSite ACS(U);
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assert(ACS && ACS.isCallbackCall());
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if (!ACS.getCalledFunction())
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continue;
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for (unsigned u = 0, e = ACS.getNumArgOperands(); u < e; u++) {
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// Test if the underlying call site operand is argument number u of the
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// callback callee.
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if (ACS.getCallArgOperandNo(u) != ArgNo)
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continue;
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assert(ACS.getCalledFunction()->arg_size() > u &&
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"ACS mapped into var-args arguments!");
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if (CBCandidateArg.hasValue()) {
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CBCandidateArg = nullptr;
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break;
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}
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CBCandidateArg = ACS.getCalledFunction()->getArg(u);
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}
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}
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// If we found a unique callback candidate argument, return it.
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if (CBCandidateArg.hasValue() && CBCandidateArg.getValue())
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return CBCandidateArg.getValue();
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// If no callbacks were found, or none used the underlying call site operand
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// exclusively, use the direct callee argument if available.
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const Function *Callee = CB.getCalledFunction();
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if (Callee && Callee->arg_size() > unsigned(ArgNo))
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return Callee->getArg(ArgNo);
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return nullptr;
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}
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ChangeStatus AbstractAttribute::update(Attributor &A) {
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ChangeStatus HasChanged = ChangeStatus::UNCHANGED;
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if (getState().isAtFixpoint())
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return HasChanged;
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LLVM_DEBUG(dbgs() << "[Attributor] Update: " << *this << "\n");
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HasChanged = updateImpl(A);
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LLVM_DEBUG(dbgs() << "[Attributor] Update " << HasChanged << " " << *this
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<< "\n");
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return HasChanged;
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}
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ChangeStatus
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IRAttributeManifest::manifestAttrs(Attributor &A, const IRPosition &IRP,
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const ArrayRef<Attribute> &DeducedAttrs) {
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Function *ScopeFn = IRP.getAnchorScope();
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IRPosition::Kind PK = IRP.getPositionKind();
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// In the following some generic code that will manifest attributes in
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// DeducedAttrs if they improve the current IR. Due to the different
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// annotation positions we use the underlying AttributeList interface.
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AttributeList Attrs;
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switch (PK) {
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case IRPosition::IRP_INVALID:
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case IRPosition::IRP_FLOAT:
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return ChangeStatus::UNCHANGED;
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case IRPosition::IRP_ARGUMENT:
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case IRPosition::IRP_FUNCTION:
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case IRPosition::IRP_RETURNED:
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Attrs = ScopeFn->getAttributes();
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break;
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case IRPosition::IRP_CALL_SITE:
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case IRPosition::IRP_CALL_SITE_RETURNED:
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case IRPosition::IRP_CALL_SITE_ARGUMENT:
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Attrs = cast<CallBase>(IRP.getAnchorValue()).getAttributes();
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break;
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}
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ChangeStatus HasChanged = ChangeStatus::UNCHANGED;
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LLVMContext &Ctx = IRP.getAnchorValue().getContext();
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for (const Attribute &Attr : DeducedAttrs) {
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if (!addIfNotExistent(Ctx, Attr, Attrs, IRP.getAttrIdx()))
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continue;
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HasChanged = ChangeStatus::CHANGED;
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}
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if (HasChanged == ChangeStatus::UNCHANGED)
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return HasChanged;
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switch (PK) {
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case IRPosition::IRP_ARGUMENT:
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case IRPosition::IRP_FUNCTION:
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case IRPosition::IRP_RETURNED:
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ScopeFn->setAttributes(Attrs);
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break;
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case IRPosition::IRP_CALL_SITE:
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case IRPosition::IRP_CALL_SITE_RETURNED:
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case IRPosition::IRP_CALL_SITE_ARGUMENT:
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cast<CallBase>(IRP.getAnchorValue()).setAttributes(Attrs);
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break;
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case IRPosition::IRP_INVALID:
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case IRPosition::IRP_FLOAT:
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break;
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}
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return HasChanged;
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}
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const IRPosition IRPosition::EmptyKey(DenseMapInfo<void *>::getEmptyKey());
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const IRPosition
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IRPosition::TombstoneKey(DenseMapInfo<void *>::getTombstoneKey());
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SubsumingPositionIterator::SubsumingPositionIterator(const IRPosition &IRP) {
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IRPositions.emplace_back(IRP);
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// Helper to determine if operand bundles on a call site are benin or
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// potentially problematic. We handle only llvm.assume for now.
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auto CanIgnoreOperandBundles = [](const CallBase &CB) {
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return (isa<IntrinsicInst>(CB) &&
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cast<IntrinsicInst>(CB).getIntrinsicID() == Intrinsic ::assume);
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};
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const auto *CB = dyn_cast<CallBase>(&IRP.getAnchorValue());
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switch (IRP.getPositionKind()) {
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case IRPosition::IRP_INVALID:
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case IRPosition::IRP_FLOAT:
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case IRPosition::IRP_FUNCTION:
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return;
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case IRPosition::IRP_ARGUMENT:
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case IRPosition::IRP_RETURNED:
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IRPositions.emplace_back(IRPosition::function(*IRP.getAnchorScope()));
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return;
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case IRPosition::IRP_CALL_SITE:
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assert(CB && "Expected call site!");
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// TODO: We need to look at the operand bundles similar to the redirection
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// in CallBase.
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if (!CB->hasOperandBundles() || CanIgnoreOperandBundles(*CB))
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if (const Function *Callee = CB->getCalledFunction())
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IRPositions.emplace_back(IRPosition::function(*Callee));
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return;
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case IRPosition::IRP_CALL_SITE_RETURNED:
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assert(CB && "Expected call site!");
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// TODO: We need to look at the operand bundles similar to the redirection
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// in CallBase.
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if (!CB->hasOperandBundles() || CanIgnoreOperandBundles(*CB)) {
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if (const Function *Callee = CB->getCalledFunction()) {
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IRPositions.emplace_back(IRPosition::returned(*Callee));
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IRPositions.emplace_back(IRPosition::function(*Callee));
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for (const Argument &Arg : Callee->args())
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if (Arg.hasReturnedAttr()) {
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IRPositions.emplace_back(
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IRPosition::callsite_argument(*CB, Arg.getArgNo()));
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IRPositions.emplace_back(
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IRPosition::value(*CB->getArgOperand(Arg.getArgNo())));
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IRPositions.emplace_back(IRPosition::argument(Arg));
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}
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}
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}
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IRPositions.emplace_back(IRPosition::callsite_function(*CB));
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return;
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case IRPosition::IRP_CALL_SITE_ARGUMENT: {
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assert(CB && "Expected call site!");
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// TODO: We need to look at the operand bundles similar to the redirection
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// in CallBase.
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if (!CB->hasOperandBundles() || CanIgnoreOperandBundles(*CB)) {
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const Function *Callee = CB->getCalledFunction();
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if (Callee) {
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if (Argument *Arg = IRP.getAssociatedArgument())
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IRPositions.emplace_back(IRPosition::argument(*Arg));
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IRPositions.emplace_back(IRPosition::function(*Callee));
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}
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}
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IRPositions.emplace_back(IRPosition::value(IRP.getAssociatedValue()));
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return;
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}
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}
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}
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bool IRPosition::hasAttr(ArrayRef<Attribute::AttrKind> AKs,
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bool IgnoreSubsumingPositions, Attributor *A) const {
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SmallVector<Attribute, 4> Attrs;
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for (const IRPosition &EquivIRP : SubsumingPositionIterator(*this)) {
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for (Attribute::AttrKind AK : AKs)
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if (EquivIRP.getAttrsFromIRAttr(AK, Attrs))
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return true;
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// The first position returned by the SubsumingPositionIterator is
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// always the position itself. If we ignore subsuming positions we
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// are done after the first iteration.
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if (IgnoreSubsumingPositions)
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break;
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}
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if (A)
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for (Attribute::AttrKind AK : AKs)
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if (getAttrsFromAssumes(AK, Attrs, *A))
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return true;
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return false;
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}
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void IRPosition::getAttrs(ArrayRef<Attribute::AttrKind> AKs,
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SmallVectorImpl<Attribute> &Attrs,
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bool IgnoreSubsumingPositions, Attributor *A) const {
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for (const IRPosition &EquivIRP : SubsumingPositionIterator(*this)) {
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for (Attribute::AttrKind AK : AKs)
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EquivIRP.getAttrsFromIRAttr(AK, Attrs);
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// The first position returned by the SubsumingPositionIterator is
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// always the position itself. If we ignore subsuming positions we
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// are done after the first iteration.
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if (IgnoreSubsumingPositions)
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break;
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}
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if (A)
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for (Attribute::AttrKind AK : AKs)
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getAttrsFromAssumes(AK, Attrs, *A);
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}
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bool IRPosition::getAttrsFromIRAttr(Attribute::AttrKind AK,
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SmallVectorImpl<Attribute> &Attrs) const {
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if (getPositionKind() == IRP_INVALID || getPositionKind() == IRP_FLOAT)
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return false;
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AttributeList AttrList;
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if (const auto *CB = dyn_cast<CallBase>(&getAnchorValue()))
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AttrList = CB->getAttributes();
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else
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AttrList = getAssociatedFunction()->getAttributes();
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bool HasAttr = AttrList.hasAttribute(getAttrIdx(), AK);
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if (HasAttr)
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Attrs.push_back(AttrList.getAttribute(getAttrIdx(), AK));
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return HasAttr;
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}
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bool IRPosition::getAttrsFromAssumes(Attribute::AttrKind AK,
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SmallVectorImpl<Attribute> &Attrs,
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Attributor &A) const {
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assert(getPositionKind() != IRP_INVALID && "Did expect a valid position!");
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Value &AssociatedValue = getAssociatedValue();
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const Assume2KnowledgeMap &A2K =
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A.getInfoCache().getKnowledgeMap().lookup({&AssociatedValue, AK});
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// Check if we found any potential assume use, if not we don't need to create
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// explorer iterators.
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if (A2K.empty())
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return false;
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LLVMContext &Ctx = AssociatedValue.getContext();
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unsigned AttrsSize = Attrs.size();
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MustBeExecutedContextExplorer &Explorer =
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A.getInfoCache().getMustBeExecutedContextExplorer();
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auto EIt = Explorer.begin(getCtxI()), EEnd = Explorer.end(getCtxI());
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for (auto &It : A2K)
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if (Explorer.findInContextOf(It.first, EIt, EEnd))
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Attrs.push_back(Attribute::get(Ctx, AK, It.second.Max));
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return AttrsSize != Attrs.size();
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}
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|
|
void IRPosition::verify() {
|
|
#ifdef EXPENSIVE_CHECKS
|
|
switch (getPositionKind()) {
|
|
case IRP_INVALID:
|
|
assert(!Enc.getOpaqueValue() &&
|
|
"Expected a nullptr for an invalid position!");
|
|
return;
|
|
case IRP_FLOAT:
|
|
assert((!isa<CallBase>(&getAssociatedValue()) &&
|
|
!isa<Argument>(&getAssociatedValue())) &&
|
|
"Expected specialized kind for call base and argument values!");
|
|
return;
|
|
case IRP_RETURNED:
|
|
assert(isa<Function>(getAsValuePtr()) &&
|
|
"Expected function for a 'returned' position!");
|
|
assert(getAsValuePtr() == &getAssociatedValue() &&
|
|
"Associated value mismatch!");
|
|
return;
|
|
case IRP_CALL_SITE_RETURNED:
|
|
assert((isa<CallBase>(getAsValuePtr())) &&
|
|
"Expected call base for 'call site returned' position!");
|
|
assert(getAsValuePtr() == &getAssociatedValue() &&
|
|
"Associated value mismatch!");
|
|
return;
|
|
case IRP_CALL_SITE:
|
|
assert((isa<CallBase>(getAsValuePtr())) &&
|
|
"Expected call base for 'call site function' position!");
|
|
assert(getAsValuePtr() == &getAssociatedValue() &&
|
|
"Associated value mismatch!");
|
|
return;
|
|
case IRP_FUNCTION:
|
|
assert(isa<Function>(getAsValuePtr()) &&
|
|
"Expected function for a 'function' position!");
|
|
assert(getAsValuePtr() == &getAssociatedValue() &&
|
|
"Associated value mismatch!");
|
|
return;
|
|
case IRP_ARGUMENT:
|
|
assert(isa<Argument>(getAsValuePtr()) &&
|
|
"Expected argument for a 'argument' position!");
|
|
assert(getAsValuePtr() == &getAssociatedValue() &&
|
|
"Associated value mismatch!");
|
|
return;
|
|
case IRP_CALL_SITE_ARGUMENT: {
|
|
Use *U = getAsUsePtr();
|
|
assert(U && "Expected use for a 'call site argument' position!");
|
|
assert(isa<CallBase>(U->getUser()) &&
|
|
"Expected call base user for a 'call site argument' position!");
|
|
assert(cast<CallBase>(U->getUser())->isArgOperand(U) &&
|
|
"Expected call base argument operand for a 'call site argument' "
|
|
"position");
|
|
assert(cast<CallBase>(U->getUser())->getArgOperandNo(U) ==
|
|
unsigned(getCallSiteArgNo()) &&
|
|
"Argument number mismatch!");
|
|
assert(U->get() == &getAssociatedValue() && "Associated value mismatch!");
|
|
return;
|
|
}
|
|
}
|
|
#endif
|
|
}
|
|
|
|
Optional<Constant *>
|
|
Attributor::getAssumedConstant(const Value &V, const AbstractAttribute &AA,
|
|
bool &UsedAssumedInformation) {
|
|
const auto &ValueSimplifyAA = getAAFor<AAValueSimplify>(
|
|
AA, IRPosition::value(V), /* TrackDependence */ false);
|
|
Optional<Value *> SimplifiedV =
|
|
ValueSimplifyAA.getAssumedSimplifiedValue(*this);
|
|
bool IsKnown = ValueSimplifyAA.isKnown();
|
|
UsedAssumedInformation |= !IsKnown;
|
|
if (!SimplifiedV.hasValue()) {
|
|
recordDependence(ValueSimplifyAA, AA, DepClassTy::OPTIONAL);
|
|
return llvm::None;
|
|
}
|
|
if (isa_and_nonnull<UndefValue>(SimplifiedV.getValue())) {
|
|
recordDependence(ValueSimplifyAA, AA, DepClassTy::OPTIONAL);
|
|
return llvm::None;
|
|
}
|
|
Constant *CI = dyn_cast_or_null<Constant>(SimplifiedV.getValue());
|
|
if (CI && CI->getType() != V.getType()) {
|
|
// TODO: Check for a save conversion.
|
|
return nullptr;
|
|
}
|
|
if (CI)
|
|
recordDependence(ValueSimplifyAA, AA, DepClassTy::OPTIONAL);
|
|
return CI;
|
|
}
|
|
|
|
Attributor::~Attributor() {
|
|
// The abstract attributes are allocated via the BumpPtrAllocator Allocator,
|
|
// thus we cannot delete them. We can, and want to, destruct them though.
|
|
for (auto &DepAA : DG.SyntheticRoot.Deps) {
|
|
AbstractAttribute *AA = cast<AbstractAttribute>(DepAA.getPointer());
|
|
AA->~AbstractAttribute();
|
|
}
|
|
}
|
|
|
|
bool Attributor::isAssumedDead(const AbstractAttribute &AA,
|
|
const AAIsDead *FnLivenessAA,
|
|
bool CheckBBLivenessOnly, DepClassTy DepClass) {
|
|
const IRPosition &IRP = AA.getIRPosition();
|
|
if (!Functions.count(IRP.getAnchorScope()))
|
|
return false;
|
|
return isAssumedDead(IRP, &AA, FnLivenessAA, CheckBBLivenessOnly, DepClass);
|
|
}
|
|
|
|
bool Attributor::isAssumedDead(const Use &U,
|
|
const AbstractAttribute *QueryingAA,
|
|
const AAIsDead *FnLivenessAA,
|
|
bool CheckBBLivenessOnly, DepClassTy DepClass) {
|
|
Instruction *UserI = dyn_cast<Instruction>(U.getUser());
|
|
if (!UserI)
|
|
return isAssumedDead(IRPosition::value(*U.get()), QueryingAA, FnLivenessAA,
|
|
CheckBBLivenessOnly, DepClass);
|
|
|
|
if (auto *CB = dyn_cast<CallBase>(UserI)) {
|
|
// For call site argument uses we can check if the argument is
|
|
// unused/dead.
|
|
if (CB->isArgOperand(&U)) {
|
|
const IRPosition &CSArgPos =
|
|
IRPosition::callsite_argument(*CB, CB->getArgOperandNo(&U));
|
|
return isAssumedDead(CSArgPos, QueryingAA, FnLivenessAA,
|
|
CheckBBLivenessOnly, DepClass);
|
|
}
|
|
} else if (ReturnInst *RI = dyn_cast<ReturnInst>(UserI)) {
|
|
const IRPosition &RetPos = IRPosition::returned(*RI->getFunction());
|
|
return isAssumedDead(RetPos, QueryingAA, FnLivenessAA, CheckBBLivenessOnly,
|
|
DepClass);
|
|
} else if (PHINode *PHI = dyn_cast<PHINode>(UserI)) {
|
|
BasicBlock *IncomingBB = PHI->getIncomingBlock(U);
|
|
return isAssumedDead(*IncomingBB->getTerminator(), QueryingAA, FnLivenessAA,
|
|
CheckBBLivenessOnly, DepClass);
|
|
}
|
|
|
|
return isAssumedDead(IRPosition::value(*UserI), QueryingAA, FnLivenessAA,
|
|
CheckBBLivenessOnly, DepClass);
|
|
}
|
|
|
|
bool Attributor::isAssumedDead(const Instruction &I,
|
|
const AbstractAttribute *QueryingAA,
|
|
const AAIsDead *FnLivenessAA,
|
|
bool CheckBBLivenessOnly, DepClassTy DepClass) {
|
|
if (!FnLivenessAA)
|
|
FnLivenessAA = lookupAAFor<AAIsDead>(IRPosition::function(*I.getFunction()),
|
|
QueryingAA,
|
|
/* TrackDependence */ false);
|
|
|
|
// If we have a context instruction and a liveness AA we use it.
|
|
if (FnLivenessAA &&
|
|
FnLivenessAA->getIRPosition().getAnchorScope() == I.getFunction() &&
|
|
FnLivenessAA->isAssumedDead(&I)) {
|
|
if (QueryingAA)
|
|
recordDependence(*FnLivenessAA, *QueryingAA, DepClass);
|
|
return true;
|
|
}
|
|
|
|
if (CheckBBLivenessOnly)
|
|
return false;
|
|
|
|
const AAIsDead &IsDeadAA = getOrCreateAAFor<AAIsDead>(
|
|
IRPosition::value(I), QueryingAA, /* TrackDependence */ false);
|
|
// Don't check liveness for AAIsDead.
|
|
if (QueryingAA == &IsDeadAA)
|
|
return false;
|
|
|
|
if (IsDeadAA.isAssumedDead()) {
|
|
if (QueryingAA)
|
|
recordDependence(IsDeadAA, *QueryingAA, DepClass);
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
bool Attributor::isAssumedDead(const IRPosition &IRP,
|
|
const AbstractAttribute *QueryingAA,
|
|
const AAIsDead *FnLivenessAA,
|
|
bool CheckBBLivenessOnly, DepClassTy DepClass) {
|
|
Instruction *CtxI = IRP.getCtxI();
|
|
if (CtxI &&
|
|
isAssumedDead(*CtxI, QueryingAA, FnLivenessAA,
|
|
/* CheckBBLivenessOnly */ true,
|
|
CheckBBLivenessOnly ? DepClass : DepClassTy::OPTIONAL))
|
|
return true;
|
|
|
|
if (CheckBBLivenessOnly)
|
|
return false;
|
|
|
|
// If we haven't succeeded we query the specific liveness info for the IRP.
|
|
const AAIsDead *IsDeadAA;
|
|
if (IRP.getPositionKind() == IRPosition::IRP_CALL_SITE)
|
|
IsDeadAA = &getOrCreateAAFor<AAIsDead>(
|
|
IRPosition::callsite_returned(cast<CallBase>(IRP.getAssociatedValue())),
|
|
QueryingAA, /* TrackDependence */ false);
|
|
else
|
|
IsDeadAA = &getOrCreateAAFor<AAIsDead>(IRP, QueryingAA,
|
|
/* TrackDependence */ false);
|
|
// Don't check liveness for AAIsDead.
|
|
if (QueryingAA == IsDeadAA)
|
|
return false;
|
|
|
|
if (IsDeadAA->isAssumedDead()) {
|
|
if (QueryingAA)
|
|
recordDependence(*IsDeadAA, *QueryingAA, DepClass);
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
bool Attributor::checkForAllUses(function_ref<bool(const Use &, bool &)> Pred,
|
|
const AbstractAttribute &QueryingAA,
|
|
const Value &V, DepClassTy LivenessDepClass) {
|
|
|
|
// Check the trivial case first as it catches void values.
|
|
if (V.use_empty())
|
|
return true;
|
|
|
|
// If the value is replaced by another one, for now a constant, we do not have
|
|
// uses. Note that this requires users of `checkForAllUses` to not recurse but
|
|
// instead use the `follow` callback argument to look at transitive users,
|
|
// however, that should be clear from the presence of the argument.
|
|
bool UsedAssumedInformation = false;
|
|
Optional<Constant *> C =
|
|
getAssumedConstant(V, QueryingAA, UsedAssumedInformation);
|
|
if (C.hasValue() && C.getValue()) {
|
|
LLVM_DEBUG(dbgs() << "[Attributor] Value is simplified, uses skipped: " << V
|
|
<< " -> " << *C.getValue() << "\n");
|
|
return true;
|
|
}
|
|
|
|
const IRPosition &IRP = QueryingAA.getIRPosition();
|
|
SmallVector<const Use *, 16> Worklist;
|
|
SmallPtrSet<const Use *, 16> Visited;
|
|
|
|
for (const Use &U : V.uses())
|
|
Worklist.push_back(&U);
|
|
|
|
LLVM_DEBUG(dbgs() << "[Attributor] Got " << Worklist.size()
|
|
<< " initial uses to check\n");
|
|
|
|
const Function *ScopeFn = IRP.getAnchorScope();
|
|
const auto *LivenessAA =
|
|
ScopeFn ? &getAAFor<AAIsDead>(QueryingAA, IRPosition::function(*ScopeFn),
|
|
/* TrackDependence */ false)
|
|
: nullptr;
|
|
|
|
while (!Worklist.empty()) {
|
|
const Use *U = Worklist.pop_back_val();
|
|
if (!Visited.insert(U).second)
|
|
continue;
|
|
LLVM_DEBUG(dbgs() << "[Attributor] Check use: " << **U << " in "
|
|
<< *U->getUser() << "\n");
|
|
if (isAssumedDead(*U, &QueryingAA, LivenessAA,
|
|
/* CheckBBLivenessOnly */ false, LivenessDepClass)) {
|
|
LLVM_DEBUG(dbgs() << "[Attributor] Dead use, skip!\n");
|
|
continue;
|
|
}
|
|
if (U->getUser()->isDroppable()) {
|
|
LLVM_DEBUG(dbgs() << "[Attributor] Droppable user, skip!\n");
|
|
continue;
|
|
}
|
|
|
|
bool Follow = false;
|
|
if (!Pred(*U, Follow))
|
|
return false;
|
|
if (!Follow)
|
|
continue;
|
|
for (const Use &UU : U->getUser()->uses())
|
|
Worklist.push_back(&UU);
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
bool Attributor::checkForAllCallSites(function_ref<bool(AbstractCallSite)> Pred,
|
|
const AbstractAttribute &QueryingAA,
|
|
bool RequireAllCallSites,
|
|
bool &AllCallSitesKnown) {
|
|
// We can try to determine information from
|
|
// the call sites. However, this is only possible all call sites are known,
|
|
// hence the function has internal linkage.
|
|
const IRPosition &IRP = QueryingAA.getIRPosition();
|
|
const Function *AssociatedFunction = IRP.getAssociatedFunction();
|
|
if (!AssociatedFunction) {
|
|
LLVM_DEBUG(dbgs() << "[Attributor] No function associated with " << IRP
|
|
<< "\n");
|
|
AllCallSitesKnown = false;
|
|
return false;
|
|
}
|
|
|
|
return checkForAllCallSites(Pred, *AssociatedFunction, RequireAllCallSites,
|
|
&QueryingAA, AllCallSitesKnown);
|
|
}
|
|
|
|
bool Attributor::checkForAllCallSites(function_ref<bool(AbstractCallSite)> Pred,
|
|
const Function &Fn,
|
|
bool RequireAllCallSites,
|
|
const AbstractAttribute *QueryingAA,
|
|
bool &AllCallSitesKnown) {
|
|
if (RequireAllCallSites && !Fn.hasLocalLinkage()) {
|
|
LLVM_DEBUG(
|
|
dbgs()
|
|
<< "[Attributor] Function " << Fn.getName()
|
|
<< " has no internal linkage, hence not all call sites are known\n");
|
|
AllCallSitesKnown = false;
|
|
return false;
|
|
}
|
|
|
|
// If we do not require all call sites we might not see all.
|
|
AllCallSitesKnown = RequireAllCallSites;
|
|
|
|
SmallVector<const Use *, 8> Uses(make_pointer_range(Fn.uses()));
|
|
for (unsigned u = 0; u < Uses.size(); ++u) {
|
|
const Use &U = *Uses[u];
|
|
LLVM_DEBUG(dbgs() << "[Attributor] Check use: " << *U << " in "
|
|
<< *U.getUser() << "\n");
|
|
if (isAssumedDead(U, QueryingAA, nullptr, /* CheckBBLivenessOnly */ true)) {
|
|
LLVM_DEBUG(dbgs() << "[Attributor] Dead use, skip!\n");
|
|
continue;
|
|
}
|
|
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(U.getUser())) {
|
|
if (CE->isCast() && CE->getType()->isPointerTy() &&
|
|
CE->getType()->getPointerElementType()->isFunctionTy()) {
|
|
for (const Use &CEU : CE->uses())
|
|
Uses.push_back(&CEU);
|
|
continue;
|
|
}
|
|
}
|
|
|
|
AbstractCallSite ACS(&U);
|
|
if (!ACS) {
|
|
LLVM_DEBUG(dbgs() << "[Attributor] Function " << Fn.getName()
|
|
<< " has non call site use " << *U.get() << " in "
|
|
<< *U.getUser() << "\n");
|
|
// BlockAddress users are allowed.
|
|
if (isa<BlockAddress>(U.getUser()))
|
|
continue;
|
|
return false;
|
|
}
|
|
|
|
const Use *EffectiveUse =
|
|
ACS.isCallbackCall() ? &ACS.getCalleeUseForCallback() : &U;
|
|
if (!ACS.isCallee(EffectiveUse)) {
|
|
if (!RequireAllCallSites)
|
|
continue;
|
|
LLVM_DEBUG(dbgs() << "[Attributor] User " << EffectiveUse->getUser()
|
|
<< " is an invalid use of " << Fn.getName() << "\n");
|
|
return false;
|
|
}
|
|
|
|
// Make sure the arguments that can be matched between the call site and the
|
|
// callee argee on their type. It is unlikely they do not and it doesn't
|
|
// make sense for all attributes to know/care about this.
|
|
assert(&Fn == ACS.getCalledFunction() && "Expected known callee");
|
|
unsigned MinArgsParams =
|
|
std::min(size_t(ACS.getNumArgOperands()), Fn.arg_size());
|
|
for (unsigned u = 0; u < MinArgsParams; ++u) {
|
|
Value *CSArgOp = ACS.getCallArgOperand(u);
|
|
if (CSArgOp && Fn.getArg(u)->getType() != CSArgOp->getType()) {
|
|
LLVM_DEBUG(
|
|
dbgs() << "[Attributor] Call site / callee argument type mismatch ["
|
|
<< u << "@" << Fn.getName() << ": "
|
|
<< *Fn.getArg(u)->getType() << " vs. "
|
|
<< *ACS.getCallArgOperand(u)->getType() << "\n");
|
|
return false;
|
|
}
|
|
}
|
|
|
|
if (Pred(ACS))
|
|
continue;
|
|
|
|
LLVM_DEBUG(dbgs() << "[Attributor] Call site callback failed for "
|
|
<< *ACS.getInstruction() << "\n");
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
bool Attributor::checkForAllReturnedValuesAndReturnInsts(
|
|
function_ref<bool(Value &, const SmallSetVector<ReturnInst *, 4> &)> Pred,
|
|
const AbstractAttribute &QueryingAA) {
|
|
|
|
const IRPosition &IRP = QueryingAA.getIRPosition();
|
|
// Since we need to provide return instructions we have to have an exact
|
|
// definition.
|
|
const Function *AssociatedFunction = IRP.getAssociatedFunction();
|
|
if (!AssociatedFunction)
|
|
return false;
|
|
|
|
// If this is a call site query we use the call site specific return values
|
|
// and liveness information.
|
|
// TODO: use the function scope once we have call site AAReturnedValues.
|
|
const IRPosition &QueryIRP = IRPosition::function(*AssociatedFunction);
|
|
const auto &AARetVal = getAAFor<AAReturnedValues>(QueryingAA, QueryIRP);
|
|
if (!AARetVal.getState().isValidState())
|
|
return false;
|
|
|
|
return AARetVal.checkForAllReturnedValuesAndReturnInsts(Pred);
|
|
}
|
|
|
|
bool Attributor::checkForAllReturnedValues(
|
|
function_ref<bool(Value &)> Pred, const AbstractAttribute &QueryingAA) {
|
|
|
|
const IRPosition &IRP = QueryingAA.getIRPosition();
|
|
const Function *AssociatedFunction = IRP.getAssociatedFunction();
|
|
if (!AssociatedFunction)
|
|
return false;
|
|
|
|
// TODO: use the function scope once we have call site AAReturnedValues.
|
|
const IRPosition &QueryIRP = IRPosition::function(*AssociatedFunction);
|
|
const auto &AARetVal = getAAFor<AAReturnedValues>(QueryingAA, QueryIRP);
|
|
if (!AARetVal.getState().isValidState())
|
|
return false;
|
|
|
|
return AARetVal.checkForAllReturnedValuesAndReturnInsts(
|
|
[&](Value &RV, const SmallSetVector<ReturnInst *, 4> &) {
|
|
return Pred(RV);
|
|
});
|
|
}
|
|
|
|
static bool checkForAllInstructionsImpl(
|
|
Attributor *A, InformationCache::OpcodeInstMapTy &OpcodeInstMap,
|
|
function_ref<bool(Instruction &)> Pred, const AbstractAttribute *QueryingAA,
|
|
const AAIsDead *LivenessAA, const ArrayRef<unsigned> &Opcodes,
|
|
bool CheckBBLivenessOnly = false) {
|
|
for (unsigned Opcode : Opcodes) {
|
|
// Check if we have instructions with this opcode at all first.
|
|
auto *Insts = OpcodeInstMap.lookup(Opcode);
|
|
if (!Insts)
|
|
continue;
|
|
|
|
for (Instruction *I : *Insts) {
|
|
// Skip dead instructions.
|
|
if (A && A->isAssumedDead(IRPosition::value(*I), QueryingAA, LivenessAA,
|
|
CheckBBLivenessOnly))
|
|
continue;
|
|
|
|
if (!Pred(*I))
|
|
return false;
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
bool Attributor::checkForAllInstructions(function_ref<bool(Instruction &)> Pred,
|
|
const AbstractAttribute &QueryingAA,
|
|
const ArrayRef<unsigned> &Opcodes,
|
|
bool CheckBBLivenessOnly) {
|
|
|
|
const IRPosition &IRP = QueryingAA.getIRPosition();
|
|
// Since we need to provide instructions we have to have an exact definition.
|
|
const Function *AssociatedFunction = IRP.getAssociatedFunction();
|
|
if (!AssociatedFunction)
|
|
return false;
|
|
|
|
// TODO: use the function scope once we have call site AAReturnedValues.
|
|
const IRPosition &QueryIRP = IRPosition::function(*AssociatedFunction);
|
|
const auto *LivenessAA =
|
|
CheckBBLivenessOnly ? nullptr
|
|
: &(getAAFor<AAIsDead>(QueryingAA, QueryIRP,
|
|
/* TrackDependence */ false));
|
|
|
|
auto &OpcodeInstMap =
|
|
InfoCache.getOpcodeInstMapForFunction(*AssociatedFunction);
|
|
if (!checkForAllInstructionsImpl(this, OpcodeInstMap, Pred, &QueryingAA,
|
|
LivenessAA, Opcodes, CheckBBLivenessOnly))
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
bool Attributor::checkForAllReadWriteInstructions(
|
|
function_ref<bool(Instruction &)> Pred, AbstractAttribute &QueryingAA) {
|
|
|
|
const Function *AssociatedFunction =
|
|
QueryingAA.getIRPosition().getAssociatedFunction();
|
|
if (!AssociatedFunction)
|
|
return false;
|
|
|
|
// TODO: use the function scope once we have call site AAReturnedValues.
|
|
const IRPosition &QueryIRP = IRPosition::function(*AssociatedFunction);
|
|
const auto &LivenessAA =
|
|
getAAFor<AAIsDead>(QueryingAA, QueryIRP, /* TrackDependence */ false);
|
|
|
|
for (Instruction *I :
|
|
InfoCache.getReadOrWriteInstsForFunction(*AssociatedFunction)) {
|
|
// Skip dead instructions.
|
|
if (isAssumedDead(IRPosition::value(*I), &QueryingAA, &LivenessAA))
|
|
continue;
|
|
|
|
if (!Pred(*I))
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
void Attributor::runTillFixpoint() {
|
|
TimeTraceScope TimeScope("Attributor::runTillFixpoint");
|
|
LLVM_DEBUG(dbgs() << "[Attributor] Identified and initialized "
|
|
<< DG.SyntheticRoot.Deps.size()
|
|
<< " abstract attributes.\n");
|
|
|
|
// Now that all abstract attributes are collected and initialized we start
|
|
// the abstract analysis.
|
|
|
|
unsigned IterationCounter = 1;
|
|
|
|
SmallVector<AbstractAttribute *, 32> ChangedAAs;
|
|
SetVector<AbstractAttribute *> Worklist, InvalidAAs;
|
|
Worklist.insert(DG.SyntheticRoot.begin(), DG.SyntheticRoot.end());
|
|
|
|
do {
|
|
// Remember the size to determine new attributes.
|
|
size_t NumAAs = DG.SyntheticRoot.Deps.size();
|
|
LLVM_DEBUG(dbgs() << "\n\n[Attributor] #Iteration: " << IterationCounter
|
|
<< ", Worklist size: " << Worklist.size() << "\n");
|
|
|
|
// For invalid AAs we can fix dependent AAs that have a required dependence,
|
|
// thereby folding long dependence chains in a single step without the need
|
|
// to run updates.
|
|
for (unsigned u = 0; u < InvalidAAs.size(); ++u) {
|
|
AbstractAttribute *InvalidAA = InvalidAAs[u];
|
|
|
|
// Check the dependences to fast track invalidation.
|
|
LLVM_DEBUG(dbgs() << "[Attributor] InvalidAA: " << *InvalidAA << " has "
|
|
<< InvalidAA->Deps.size()
|
|
<< " required & optional dependences\n");
|
|
while (!InvalidAA->Deps.empty()) {
|
|
const auto &Dep = InvalidAA->Deps.back();
|
|
InvalidAA->Deps.pop_back();
|
|
AbstractAttribute *DepAA = cast<AbstractAttribute>(Dep.getPointer());
|
|
if (Dep.getInt() == unsigned(DepClassTy::OPTIONAL)) {
|
|
Worklist.insert(DepAA);
|
|
continue;
|
|
}
|
|
DepAA->getState().indicatePessimisticFixpoint();
|
|
assert(DepAA->getState().isAtFixpoint() && "Expected fixpoint state!");
|
|
if (!DepAA->getState().isValidState())
|
|
InvalidAAs.insert(DepAA);
|
|
else
|
|
ChangedAAs.push_back(DepAA);
|
|
}
|
|
}
|
|
|
|
// Add all abstract attributes that are potentially dependent on one that
|
|
// changed to the work list.
|
|
for (AbstractAttribute *ChangedAA : ChangedAAs)
|
|
while (!ChangedAA->Deps.empty()) {
|
|
Worklist.insert(
|
|
cast<AbstractAttribute>(ChangedAA->Deps.back().getPointer()));
|
|
ChangedAA->Deps.pop_back();
|
|
}
|
|
|
|
LLVM_DEBUG(dbgs() << "[Attributor] #Iteration: " << IterationCounter
|
|
<< ", Worklist+Dependent size: " << Worklist.size()
|
|
<< "\n");
|
|
|
|
// Reset the changed and invalid set.
|
|
ChangedAAs.clear();
|
|
InvalidAAs.clear();
|
|
|
|
// Update all abstract attribute in the work list and record the ones that
|
|
// changed.
|
|
for (AbstractAttribute *AA : Worklist) {
|
|
const auto &AAState = AA->getState();
|
|
if (!AAState.isAtFixpoint())
|
|
if (updateAA(*AA) == ChangeStatus::CHANGED)
|
|
ChangedAAs.push_back(AA);
|
|
|
|
// Use the InvalidAAs vector to propagate invalid states fast transitively
|
|
// without requiring updates.
|
|
if (!AAState.isValidState())
|
|
InvalidAAs.insert(AA);
|
|
}
|
|
|
|
// Add attributes to the changed set if they have been created in the last
|
|
// iteration.
|
|
ChangedAAs.append(DG.SyntheticRoot.begin() + NumAAs,
|
|
DG.SyntheticRoot.end());
|
|
|
|
// Reset the work list and repopulate with the changed abstract attributes.
|
|
// Note that dependent ones are added above.
|
|
Worklist.clear();
|
|
Worklist.insert(ChangedAAs.begin(), ChangedAAs.end());
|
|
|
|
} while (!Worklist.empty() && (IterationCounter++ < MaxFixpointIterations ||
|
|
VerifyMaxFixpointIterations));
|
|
|
|
LLVM_DEBUG(dbgs() << "\n[Attributor] Fixpoint iteration done after: "
|
|
<< IterationCounter << "/" << MaxFixpointIterations
|
|
<< " iterations\n");
|
|
|
|
// Reset abstract arguments not settled in a sound fixpoint by now. This
|
|
// happens when we stopped the fixpoint iteration early. Note that only the
|
|
// ones marked as "changed" *and* the ones transitively depending on them
|
|
// need to be reverted to a pessimistic state. Others might not be in a
|
|
// fixpoint state but we can use the optimistic results for them anyway.
|
|
SmallPtrSet<AbstractAttribute *, 32> Visited;
|
|
for (unsigned u = 0; u < ChangedAAs.size(); u++) {
|
|
AbstractAttribute *ChangedAA = ChangedAAs[u];
|
|
if (!Visited.insert(ChangedAA).second)
|
|
continue;
|
|
|
|
AbstractState &State = ChangedAA->getState();
|
|
if (!State.isAtFixpoint()) {
|
|
State.indicatePessimisticFixpoint();
|
|
|
|
NumAttributesTimedOut++;
|
|
}
|
|
|
|
while (!ChangedAA->Deps.empty()) {
|
|
ChangedAAs.push_back(
|
|
cast<AbstractAttribute>(ChangedAA->Deps.back().getPointer()));
|
|
ChangedAA->Deps.pop_back();
|
|
}
|
|
}
|
|
|
|
LLVM_DEBUG({
|
|
if (!Visited.empty())
|
|
dbgs() << "\n[Attributor] Finalized " << Visited.size()
|
|
<< " abstract attributes.\n";
|
|
});
|
|
|
|
if (VerifyMaxFixpointIterations &&
|
|
IterationCounter != MaxFixpointIterations) {
|
|
errs() << "\n[Attributor] Fixpoint iteration done after: "
|
|
<< IterationCounter << "/" << MaxFixpointIterations
|
|
<< " iterations\n";
|
|
llvm_unreachable("The fixpoint was not reached with exactly the number of "
|
|
"specified iterations!");
|
|
}
|
|
}
|
|
|
|
ChangeStatus Attributor::manifestAttributes() {
|
|
TimeTraceScope TimeScope("Attributor::manifestAttributes");
|
|
size_t NumFinalAAs = DG.SyntheticRoot.Deps.size();
|
|
|
|
unsigned NumManifested = 0;
|
|
unsigned NumAtFixpoint = 0;
|
|
ChangeStatus ManifestChange = ChangeStatus::UNCHANGED;
|
|
for (auto &DepAA : DG.SyntheticRoot.Deps) {
|
|
AbstractAttribute *AA = cast<AbstractAttribute>(DepAA.getPointer());
|
|
AbstractState &State = AA->getState();
|
|
|
|
// If there is not already a fixpoint reached, we can now take the
|
|
// optimistic state. This is correct because we enforced a pessimistic one
|
|
// on abstract attributes that were transitively dependent on a changed one
|
|
// already above.
|
|
if (!State.isAtFixpoint())
|
|
State.indicateOptimisticFixpoint();
|
|
|
|
// If the state is invalid, we do not try to manifest it.
|
|
if (!State.isValidState())
|
|
continue;
|
|
|
|
// Skip dead code.
|
|
if (isAssumedDead(*AA, nullptr, /* CheckBBLivenessOnly */ true))
|
|
continue;
|
|
// Manifest the state and record if we changed the IR.
|
|
ChangeStatus LocalChange = AA->manifest(*this);
|
|
if (LocalChange == ChangeStatus::CHANGED && AreStatisticsEnabled())
|
|
AA->trackStatistics();
|
|
LLVM_DEBUG(dbgs() << "[Attributor] Manifest " << LocalChange << " : " << *AA
|
|
<< "\n");
|
|
|
|
ManifestChange = ManifestChange | LocalChange;
|
|
|
|
NumAtFixpoint++;
|
|
NumManifested += (LocalChange == ChangeStatus::CHANGED);
|
|
}
|
|
|
|
(void)NumManifested;
|
|
(void)NumAtFixpoint;
|
|
LLVM_DEBUG(dbgs() << "\n[Attributor] Manifested " << NumManifested
|
|
<< " arguments while " << NumAtFixpoint
|
|
<< " were in a valid fixpoint state\n");
|
|
|
|
NumAttributesManifested += NumManifested;
|
|
NumAttributesValidFixpoint += NumAtFixpoint;
|
|
|
|
(void)NumFinalAAs;
|
|
if (NumFinalAAs != DG.SyntheticRoot.Deps.size()) {
|
|
for (unsigned u = NumFinalAAs; u < DG.SyntheticRoot.Deps.size(); ++u)
|
|
errs() << "Unexpected abstract attribute: "
|
|
<< cast<AbstractAttribute>(DG.SyntheticRoot.Deps[u].getPointer())
|
|
<< " :: "
|
|
<< cast<AbstractAttribute>(DG.SyntheticRoot.Deps[u].getPointer())
|
|
->getIRPosition()
|
|
.getAssociatedValue()
|
|
<< "\n";
|
|
llvm_unreachable("Expected the final number of abstract attributes to "
|
|
"remain unchanged!");
|
|
}
|
|
return ManifestChange;
|
|
}
|
|
|
|
ChangeStatus Attributor::cleanupIR() {
|
|
TimeTraceScope TimeScope("Attributor::cleanupIR");
|
|
// Delete stuff at the end to avoid invalid references and a nice order.
|
|
LLVM_DEBUG(dbgs() << "\n[Attributor] Delete at least "
|
|
<< ToBeDeletedFunctions.size() << " functions and "
|
|
<< ToBeDeletedBlocks.size() << " blocks and "
|
|
<< ToBeDeletedInsts.size() << " instructions and "
|
|
<< ToBeChangedUses.size() << " uses\n");
|
|
|
|
SmallVector<WeakTrackingVH, 32> DeadInsts;
|
|
SmallVector<Instruction *, 32> TerminatorsToFold;
|
|
|
|
for (auto &It : ToBeChangedUses) {
|
|
Use *U = It.first;
|
|
Value *NewV = It.second;
|
|
Value *OldV = U->get();
|
|
|
|
// Do not replace uses in returns if the value is a must-tail call we will
|
|
// not delete.
|
|
if (isa<ReturnInst>(U->getUser()))
|
|
if (auto *CI = dyn_cast<CallInst>(OldV->stripPointerCasts()))
|
|
if (CI->isMustTailCall() && !ToBeDeletedInsts.count(CI))
|
|
continue;
|
|
|
|
LLVM_DEBUG(dbgs() << "Use " << *NewV << " in " << *U->getUser()
|
|
<< " instead of " << *OldV << "\n");
|
|
U->set(NewV);
|
|
// Do not modify call instructions outside the SCC.
|
|
if (auto *CB = dyn_cast<CallBase>(OldV))
|
|
if (!Functions.count(CB->getCaller()))
|
|
continue;
|
|
if (Instruction *I = dyn_cast<Instruction>(OldV)) {
|
|
CGModifiedFunctions.insert(I->getFunction());
|
|
if (!isa<PHINode>(I) && !ToBeDeletedInsts.count(I) &&
|
|
isInstructionTriviallyDead(I))
|
|
DeadInsts.push_back(I);
|
|
}
|
|
if (isa<Constant>(NewV) && isa<BranchInst>(U->getUser())) {
|
|
Instruction *UserI = cast<Instruction>(U->getUser());
|
|
if (isa<UndefValue>(NewV)) {
|
|
ToBeChangedToUnreachableInsts.insert(UserI);
|
|
} else {
|
|
TerminatorsToFold.push_back(UserI);
|
|
}
|
|
}
|
|
}
|
|
for (auto &V : InvokeWithDeadSuccessor)
|
|
if (InvokeInst *II = dyn_cast_or_null<InvokeInst>(V)) {
|
|
bool UnwindBBIsDead = II->hasFnAttr(Attribute::NoUnwind);
|
|
bool NormalBBIsDead = II->hasFnAttr(Attribute::NoReturn);
|
|
bool Invoke2CallAllowed =
|
|
!AAIsDead::mayCatchAsynchronousExceptions(*II->getFunction());
|
|
assert((UnwindBBIsDead || NormalBBIsDead) &&
|
|
"Invoke does not have dead successors!");
|
|
BasicBlock *BB = II->getParent();
|
|
BasicBlock *NormalDestBB = II->getNormalDest();
|
|
if (UnwindBBIsDead) {
|
|
Instruction *NormalNextIP = &NormalDestBB->front();
|
|
if (Invoke2CallAllowed) {
|
|
changeToCall(II);
|
|
NormalNextIP = BB->getTerminator();
|
|
}
|
|
if (NormalBBIsDead)
|
|
ToBeChangedToUnreachableInsts.insert(NormalNextIP);
|
|
} else {
|
|
assert(NormalBBIsDead && "Broken invariant!");
|
|
if (!NormalDestBB->getUniquePredecessor())
|
|
NormalDestBB = SplitBlockPredecessors(NormalDestBB, {BB}, ".dead");
|
|
ToBeChangedToUnreachableInsts.insert(&NormalDestBB->front());
|
|
}
|
|
}
|
|
for (Instruction *I : TerminatorsToFold) {
|
|
CGModifiedFunctions.insert(I->getFunction());
|
|
ConstantFoldTerminator(I->getParent());
|
|
}
|
|
for (auto &V : ToBeChangedToUnreachableInsts)
|
|
if (Instruction *I = dyn_cast_or_null<Instruction>(V)) {
|
|
CGModifiedFunctions.insert(I->getFunction());
|
|
changeToUnreachable(I, /* UseLLVMTrap */ false);
|
|
}
|
|
|
|
for (auto &V : ToBeDeletedInsts) {
|
|
if (Instruction *I = dyn_cast_or_null<Instruction>(V)) {
|
|
I->dropDroppableUses();
|
|
CGModifiedFunctions.insert(I->getFunction());
|
|
if (!I->getType()->isVoidTy())
|
|
I->replaceAllUsesWith(UndefValue::get(I->getType()));
|
|
if (!isa<PHINode>(I) && isInstructionTriviallyDead(I))
|
|
DeadInsts.push_back(I);
|
|
else
|
|
I->eraseFromParent();
|
|
}
|
|
}
|
|
|
|
LLVM_DEBUG(dbgs() << "[Attributor] DeadInsts size: " << DeadInsts.size()
|
|
<< "\n");
|
|
|
|
RecursivelyDeleteTriviallyDeadInstructions(DeadInsts);
|
|
|
|
if (unsigned NumDeadBlocks = ToBeDeletedBlocks.size()) {
|
|
SmallVector<BasicBlock *, 8> ToBeDeletedBBs;
|
|
ToBeDeletedBBs.reserve(NumDeadBlocks);
|
|
for (BasicBlock *BB : ToBeDeletedBlocks) {
|
|
CGModifiedFunctions.insert(BB->getParent());
|
|
ToBeDeletedBBs.push_back(BB);
|
|
}
|
|
// Actually we do not delete the blocks but squash them into a single
|
|
// unreachable but untangling branches that jump here is something we need
|
|
// to do in a more generic way.
|
|
DetatchDeadBlocks(ToBeDeletedBBs, nullptr);
|
|
}
|
|
|
|
// Identify dead internal functions and delete them. This happens outside
|
|
// the other fixpoint analysis as we might treat potentially dead functions
|
|
// as live to lower the number of iterations. If they happen to be dead, the
|
|
// below fixpoint loop will identify and eliminate them.
|
|
SmallVector<Function *, 8> InternalFns;
|
|
for (Function *F : Functions)
|
|
if (F->hasLocalLinkage())
|
|
InternalFns.push_back(F);
|
|
|
|
bool FoundDeadFn = true;
|
|
while (FoundDeadFn) {
|
|
FoundDeadFn = false;
|
|
for (unsigned u = 0, e = InternalFns.size(); u < e; ++u) {
|
|
Function *F = InternalFns[u];
|
|
if (!F)
|
|
continue;
|
|
|
|
bool AllCallSitesKnown;
|
|
if (!checkForAllCallSites(
|
|
[this](AbstractCallSite ACS) {
|
|
return ToBeDeletedFunctions.count(
|
|
ACS.getInstruction()->getFunction());
|
|
},
|
|
*F, true, nullptr, AllCallSitesKnown))
|
|
continue;
|
|
|
|
ToBeDeletedFunctions.insert(F);
|
|
InternalFns[u] = nullptr;
|
|
FoundDeadFn = true;
|
|
}
|
|
}
|
|
|
|
// Rewrite the functions as requested during manifest.
|
|
ChangeStatus ManifestChange = rewriteFunctionSignatures(CGModifiedFunctions);
|
|
|
|
for (Function *Fn : CGModifiedFunctions)
|
|
CGUpdater.reanalyzeFunction(*Fn);
|
|
|
|
for (Function *Fn : ToBeDeletedFunctions) {
|
|
if (!Functions.count(Fn))
|
|
continue;
|
|
CGUpdater.removeFunction(*Fn);
|
|
}
|
|
|
|
if (!ToBeChangedUses.empty())
|
|
ManifestChange = ChangeStatus::CHANGED;
|
|
|
|
if (!ToBeChangedToUnreachableInsts.empty())
|
|
ManifestChange = ChangeStatus::CHANGED;
|
|
|
|
if (!ToBeDeletedFunctions.empty())
|
|
ManifestChange = ChangeStatus::CHANGED;
|
|
|
|
if (!ToBeDeletedBlocks.empty())
|
|
ManifestChange = ChangeStatus::CHANGED;
|
|
|
|
if (!ToBeDeletedInsts.empty())
|
|
ManifestChange = ChangeStatus::CHANGED;
|
|
|
|
if (!InvokeWithDeadSuccessor.empty())
|
|
ManifestChange = ChangeStatus::CHANGED;
|
|
|
|
if (!DeadInsts.empty())
|
|
ManifestChange = ChangeStatus::CHANGED;
|
|
|
|
NumFnDeleted += ToBeDeletedFunctions.size();
|
|
|
|
LLVM_DEBUG(dbgs() << "[Attributor] Deleted " << NumFnDeleted
|
|
<< " functions after manifest.\n");
|
|
|
|
#ifdef EXPENSIVE_CHECKS
|
|
for (Function *F : Functions) {
|
|
if (ToBeDeletedFunctions.count(F))
|
|
continue;
|
|
assert(!verifyFunction(*F, &errs()) && "Module verification failed!");
|
|
}
|
|
#endif
|
|
|
|
return ManifestChange;
|
|
}
|
|
|
|
ChangeStatus Attributor::run() {
|
|
TimeTraceScope TimeScope("Attributor::run");
|
|
|
|
Phase = AttributorPhase::UPDATE;
|
|
runTillFixpoint();
|
|
|
|
// dump graphs on demand
|
|
if (DumpDepGraph)
|
|
DG.dumpGraph();
|
|
|
|
if (ViewDepGraph)
|
|
DG.viewGraph();
|
|
|
|
if (PrintDependencies)
|
|
DG.print();
|
|
|
|
Phase = AttributorPhase::MANIFEST;
|
|
ChangeStatus ManifestChange = manifestAttributes();
|
|
|
|
Phase = AttributorPhase::CLEANUP;
|
|
ChangeStatus CleanupChange = cleanupIR();
|
|
|
|
return ManifestChange | CleanupChange;
|
|
}
|
|
|
|
ChangeStatus Attributor::updateAA(AbstractAttribute &AA) {
|
|
TimeTraceScope TimeScope(AA.getName() + "::updateAA");
|
|
assert(Phase == AttributorPhase::UPDATE &&
|
|
"We can update AA only in the update stage!");
|
|
|
|
// Use a new dependence vector for this update.
|
|
DependenceVector DV;
|
|
DependenceStack.push_back(&DV);
|
|
|
|
auto &AAState = AA.getState();
|
|
ChangeStatus CS = ChangeStatus::UNCHANGED;
|
|
if (!isAssumedDead(AA, nullptr, /* CheckBBLivenessOnly */ true))
|
|
CS = AA.update(*this);
|
|
|
|
if (DV.empty()) {
|
|
// If the attribute did not query any non-fix information, the state
|
|
// will not change and we can indicate that right away.
|
|
AAState.indicateOptimisticFixpoint();
|
|
}
|
|
|
|
if (!AAState.isAtFixpoint())
|
|
rememberDependences();
|
|
|
|
// Verify the stack was used properly, that is we pop the dependence vector we
|
|
// put there earlier.
|
|
DependenceVector *PoppedDV = DependenceStack.pop_back_val();
|
|
(void)PoppedDV;
|
|
assert(PoppedDV == &DV && "Inconsistent usage of the dependence stack!");
|
|
|
|
return CS;
|
|
}
|
|
|
|
void Attributor::createShallowWrapper(Function &F) {
|
|
assert(!F.isDeclaration() && "Cannot create a wrapper around a declaration!");
|
|
|
|
Module &M = *F.getParent();
|
|
LLVMContext &Ctx = M.getContext();
|
|
FunctionType *FnTy = F.getFunctionType();
|
|
|
|
Function *Wrapper =
|
|
Function::Create(FnTy, F.getLinkage(), F.getAddressSpace(), F.getName());
|
|
F.setName(""); // set the inside function anonymous
|
|
M.getFunctionList().insert(F.getIterator(), Wrapper);
|
|
|
|
F.setLinkage(GlobalValue::InternalLinkage);
|
|
|
|
F.replaceAllUsesWith(Wrapper);
|
|
assert(F.use_empty() && "Uses remained after wrapper was created!");
|
|
|
|
// Move the COMDAT section to the wrapper.
|
|
// TODO: Check if we need to keep it for F as well.
|
|
Wrapper->setComdat(F.getComdat());
|
|
F.setComdat(nullptr);
|
|
|
|
// Copy all metadata and attributes but keep them on F as well.
|
|
SmallVector<std::pair<unsigned, MDNode *>, 1> MDs;
|
|
F.getAllMetadata(MDs);
|
|
for (auto MDIt : MDs)
|
|
Wrapper->addMetadata(MDIt.first, *MDIt.second);
|
|
Wrapper->setAttributes(F.getAttributes());
|
|
|
|
// Create the call in the wrapper.
|
|
BasicBlock *EntryBB = BasicBlock::Create(Ctx, "entry", Wrapper);
|
|
|
|
SmallVector<Value *, 8> Args;
|
|
Argument *FArgIt = F.arg_begin();
|
|
for (Argument &Arg : Wrapper->args()) {
|
|
Args.push_back(&Arg);
|
|
Arg.setName((FArgIt++)->getName());
|
|
}
|
|
|
|
CallInst *CI = CallInst::Create(&F, Args, "", EntryBB);
|
|
CI->setTailCall(true);
|
|
CI->addAttribute(AttributeList::FunctionIndex, Attribute::NoInline);
|
|
ReturnInst::Create(Ctx, CI->getType()->isVoidTy() ? nullptr : CI, EntryBB);
|
|
|
|
NumFnShallowWrappersCreated++;
|
|
}
|
|
|
|
/// Make another copy of the function \p F such that the copied version has
|
|
/// internal linkage afterwards and can be analysed. Then we replace all uses
|
|
/// of the original function to the copied one
|
|
///
|
|
/// Only non-exactly defined functions that have `linkonce_odr` or `weak_odr`
|
|
/// linkage can be internalized because these linkages guarantee that other
|
|
/// definitions with the same name have the same semantics as this one
|
|
///
|
|
static Function *internalizeFunction(Function &F) {
|
|
assert(AllowDeepWrapper && "Cannot create a copy if not allowed.");
|
|
assert(!F.isDeclaration() && !F.hasExactDefinition() &&
|
|
!GlobalValue::isInterposableLinkage(F.getLinkage()) &&
|
|
"Trying to internalize function which cannot be internalized.");
|
|
|
|
Module &M = *F.getParent();
|
|
FunctionType *FnTy = F.getFunctionType();
|
|
|
|
// create a copy of the current function
|
|
Function *Copied = Function::Create(FnTy, F.getLinkage(), F.getAddressSpace(),
|
|
F.getName() + ".internalized");
|
|
ValueToValueMapTy VMap;
|
|
auto *NewFArgIt = Copied->arg_begin();
|
|
for (auto &Arg : F.args()) {
|
|
auto ArgName = Arg.getName();
|
|
NewFArgIt->setName(ArgName);
|
|
VMap[&Arg] = &(*NewFArgIt++);
|
|
}
|
|
SmallVector<ReturnInst *, 8> Returns;
|
|
|
|
// Copy the body of the original function to the new one
|
|
CloneFunctionInto(Copied, &F, VMap, /* ModuleLevelChanges */ false, Returns);
|
|
|
|
// Set the linakage and visibility late as CloneFunctionInto has some implicit
|
|
// requirements.
|
|
Copied->setVisibility(GlobalValue::DefaultVisibility);
|
|
Copied->setLinkage(GlobalValue::PrivateLinkage);
|
|
|
|
// Copy metadata
|
|
SmallVector<std::pair<unsigned, MDNode *>, 1> MDs;
|
|
F.getAllMetadata(MDs);
|
|
for (auto MDIt : MDs)
|
|
Copied->addMetadata(MDIt.first, *MDIt.second);
|
|
|
|
M.getFunctionList().insert(F.getIterator(), Copied);
|
|
F.replaceAllUsesWith(Copied);
|
|
Copied->setDSOLocal(true);
|
|
|
|
return Copied;
|
|
}
|
|
|
|
bool Attributor::isValidFunctionSignatureRewrite(
|
|
Argument &Arg, ArrayRef<Type *> ReplacementTypes) {
|
|
|
|
auto CallSiteCanBeChanged = [](AbstractCallSite ACS) {
|
|
// Forbid the call site to cast the function return type. If we need to
|
|
// rewrite these functions we need to re-create a cast for the new call site
|
|
// (if the old had uses).
|
|
if (!ACS.getCalledFunction() ||
|
|
ACS.getInstruction()->getType() !=
|
|
ACS.getCalledFunction()->getReturnType())
|
|
return false;
|
|
// Forbid must-tail calls for now.
|
|
return !ACS.isCallbackCall() && !ACS.getInstruction()->isMustTailCall();
|
|
};
|
|
|
|
Function *Fn = Arg.getParent();
|
|
// Avoid var-arg functions for now.
|
|
if (Fn->isVarArg()) {
|
|
LLVM_DEBUG(dbgs() << "[Attributor] Cannot rewrite var-args functions\n");
|
|
return false;
|
|
}
|
|
|
|
// Avoid functions with complicated argument passing semantics.
|
|
AttributeList FnAttributeList = Fn->getAttributes();
|
|
if (FnAttributeList.hasAttrSomewhere(Attribute::Nest) ||
|
|
FnAttributeList.hasAttrSomewhere(Attribute::StructRet) ||
|
|
FnAttributeList.hasAttrSomewhere(Attribute::InAlloca) ||
|
|
FnAttributeList.hasAttrSomewhere(Attribute::Preallocated)) {
|
|
LLVM_DEBUG(
|
|
dbgs() << "[Attributor] Cannot rewrite due to complex attribute\n");
|
|
return false;
|
|
}
|
|
|
|
// Avoid callbacks for now.
|
|
bool AllCallSitesKnown;
|
|
if (!checkForAllCallSites(CallSiteCanBeChanged, *Fn, true, nullptr,
|
|
AllCallSitesKnown)) {
|
|
LLVM_DEBUG(dbgs() << "[Attributor] Cannot rewrite all call sites\n");
|
|
return false;
|
|
}
|
|
|
|
auto InstPred = [](Instruction &I) {
|
|
if (auto *CI = dyn_cast<CallInst>(&I))
|
|
return !CI->isMustTailCall();
|
|
return true;
|
|
};
|
|
|
|
// Forbid must-tail calls for now.
|
|
// TODO:
|
|
auto &OpcodeInstMap = InfoCache.getOpcodeInstMapForFunction(*Fn);
|
|
if (!checkForAllInstructionsImpl(nullptr, OpcodeInstMap, InstPred, nullptr,
|
|
nullptr, {Instruction::Call})) {
|
|
LLVM_DEBUG(dbgs() << "[Attributor] Cannot rewrite due to instructions\n");
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
bool Attributor::registerFunctionSignatureRewrite(
|
|
Argument &Arg, ArrayRef<Type *> ReplacementTypes,
|
|
ArgumentReplacementInfo::CalleeRepairCBTy &&CalleeRepairCB,
|
|
ArgumentReplacementInfo::ACSRepairCBTy &&ACSRepairCB) {
|
|
LLVM_DEBUG(dbgs() << "[Attributor] Register new rewrite of " << Arg << " in "
|
|
<< Arg.getParent()->getName() << " with "
|
|
<< ReplacementTypes.size() << " replacements\n");
|
|
assert(isValidFunctionSignatureRewrite(Arg, ReplacementTypes) &&
|
|
"Cannot register an invalid rewrite");
|
|
|
|
Function *Fn = Arg.getParent();
|
|
SmallVectorImpl<std::unique_ptr<ArgumentReplacementInfo>> &ARIs =
|
|
ArgumentReplacementMap[Fn];
|
|
if (ARIs.empty())
|
|
ARIs.resize(Fn->arg_size());
|
|
|
|
// If we have a replacement already with less than or equal new arguments,
|
|
// ignore this request.
|
|
std::unique_ptr<ArgumentReplacementInfo> &ARI = ARIs[Arg.getArgNo()];
|
|
if (ARI && ARI->getNumReplacementArgs() <= ReplacementTypes.size()) {
|
|
LLVM_DEBUG(dbgs() << "[Attributor] Existing rewrite is preferred\n");
|
|
return false;
|
|
}
|
|
|
|
// If we have a replacement already but we like the new one better, delete
|
|
// the old.
|
|
ARI.reset();
|
|
|
|
LLVM_DEBUG(dbgs() << "[Attributor] Register new rewrite of " << Arg << " in "
|
|
<< Arg.getParent()->getName() << " with "
|
|
<< ReplacementTypes.size() << " replacements\n");
|
|
|
|
// Remember the replacement.
|
|
ARI.reset(new ArgumentReplacementInfo(*this, Arg, ReplacementTypes,
|
|
std::move(CalleeRepairCB),
|
|
std::move(ACSRepairCB)));
|
|
|
|
return true;
|
|
}
|
|
|
|
bool Attributor::shouldSeedAttribute(AbstractAttribute &AA) {
|
|
bool Result = true;
|
|
#ifndef NDEBUG
|
|
if (SeedAllowList.size() != 0)
|
|
Result =
|
|
std::count(SeedAllowList.begin(), SeedAllowList.end(), AA.getName());
|
|
Function *Fn = AA.getAnchorScope();
|
|
if (FunctionSeedAllowList.size() != 0 && Fn)
|
|
Result &= std::count(FunctionSeedAllowList.begin(),
|
|
FunctionSeedAllowList.end(), Fn->getName());
|
|
#endif
|
|
return Result;
|
|
}
|
|
|
|
ChangeStatus Attributor::rewriteFunctionSignatures(
|
|
SmallPtrSetImpl<Function *> &ModifiedFns) {
|
|
ChangeStatus Changed = ChangeStatus::UNCHANGED;
|
|
|
|
for (auto &It : ArgumentReplacementMap) {
|
|
Function *OldFn = It.getFirst();
|
|
|
|
// Deleted functions do not require rewrites.
|
|
if (!Functions.count(OldFn) || ToBeDeletedFunctions.count(OldFn))
|
|
continue;
|
|
|
|
const SmallVectorImpl<std::unique_ptr<ArgumentReplacementInfo>> &ARIs =
|
|
It.getSecond();
|
|
assert(ARIs.size() == OldFn->arg_size() && "Inconsistent state!");
|
|
|
|
SmallVector<Type *, 16> NewArgumentTypes;
|
|
SmallVector<AttributeSet, 16> NewArgumentAttributes;
|
|
|
|
// Collect replacement argument types and copy over existing attributes.
|
|
AttributeList OldFnAttributeList = OldFn->getAttributes();
|
|
for (Argument &Arg : OldFn->args()) {
|
|
if (const std::unique_ptr<ArgumentReplacementInfo> &ARI =
|
|
ARIs[Arg.getArgNo()]) {
|
|
NewArgumentTypes.append(ARI->ReplacementTypes.begin(),
|
|
ARI->ReplacementTypes.end());
|
|
NewArgumentAttributes.append(ARI->getNumReplacementArgs(),
|
|
AttributeSet());
|
|
} else {
|
|
NewArgumentTypes.push_back(Arg.getType());
|
|
NewArgumentAttributes.push_back(
|
|
OldFnAttributeList.getParamAttributes(Arg.getArgNo()));
|
|
}
|
|
}
|
|
|
|
FunctionType *OldFnTy = OldFn->getFunctionType();
|
|
Type *RetTy = OldFnTy->getReturnType();
|
|
|
|
// Construct the new function type using the new arguments types.
|
|
FunctionType *NewFnTy =
|
|
FunctionType::get(RetTy, NewArgumentTypes, OldFnTy->isVarArg());
|
|
|
|
LLVM_DEBUG(dbgs() << "[Attributor] Function rewrite '" << OldFn->getName()
|
|
<< "' from " << *OldFn->getFunctionType() << " to "
|
|
<< *NewFnTy << "\n");
|
|
|
|
// Create the new function body and insert it into the module.
|
|
Function *NewFn = Function::Create(NewFnTy, OldFn->getLinkage(),
|
|
OldFn->getAddressSpace(), "");
|
|
OldFn->getParent()->getFunctionList().insert(OldFn->getIterator(), NewFn);
|
|
NewFn->takeName(OldFn);
|
|
NewFn->copyAttributesFrom(OldFn);
|
|
|
|
// Patch the pointer to LLVM function in debug info descriptor.
|
|
NewFn->setSubprogram(OldFn->getSubprogram());
|
|
OldFn->setSubprogram(nullptr);
|
|
|
|
// Recompute the parameter attributes list based on the new arguments for
|
|
// the function.
|
|
LLVMContext &Ctx = OldFn->getContext();
|
|
NewFn->setAttributes(AttributeList::get(
|
|
Ctx, OldFnAttributeList.getFnAttributes(),
|
|
OldFnAttributeList.getRetAttributes(), NewArgumentAttributes));
|
|
|
|
// Since we have now created the new function, splice the body of the old
|
|
// function right into the new function, leaving the old rotting hulk of the
|
|
// function empty.
|
|
NewFn->getBasicBlockList().splice(NewFn->begin(),
|
|
OldFn->getBasicBlockList());
|
|
|
|
// Fixup block addresses to reference new function.
|
|
SmallVector<BlockAddress *, 8u> BlockAddresses;
|
|
for (User *U : OldFn->users())
|
|
if (auto *BA = dyn_cast<BlockAddress>(U))
|
|
BlockAddresses.push_back(BA);
|
|
for (auto *BA : BlockAddresses)
|
|
BA->replaceAllUsesWith(BlockAddress::get(NewFn, BA->getBasicBlock()));
|
|
|
|
// Set of all "call-like" instructions that invoke the old function mapped
|
|
// to their new replacements.
|
|
SmallVector<std::pair<CallBase *, CallBase *>, 8> CallSitePairs;
|
|
|
|
// Callback to create a new "call-like" instruction for a given one.
|
|
auto CallSiteReplacementCreator = [&](AbstractCallSite ACS) {
|
|
CallBase *OldCB = cast<CallBase>(ACS.getInstruction());
|
|
const AttributeList &OldCallAttributeList = OldCB->getAttributes();
|
|
|
|
// Collect the new argument operands for the replacement call site.
|
|
SmallVector<Value *, 16> NewArgOperands;
|
|
SmallVector<AttributeSet, 16> NewArgOperandAttributes;
|
|
for (unsigned OldArgNum = 0; OldArgNum < ARIs.size(); ++OldArgNum) {
|
|
unsigned NewFirstArgNum = NewArgOperands.size();
|
|
(void)NewFirstArgNum; // only used inside assert.
|
|
if (const std::unique_ptr<ArgumentReplacementInfo> &ARI =
|
|
ARIs[OldArgNum]) {
|
|
if (ARI->ACSRepairCB)
|
|
ARI->ACSRepairCB(*ARI, ACS, NewArgOperands);
|
|
assert(ARI->getNumReplacementArgs() + NewFirstArgNum ==
|
|
NewArgOperands.size() &&
|
|
"ACS repair callback did not provide as many operand as new "
|
|
"types were registered!");
|
|
// TODO: Exose the attribute set to the ACS repair callback
|
|
NewArgOperandAttributes.append(ARI->ReplacementTypes.size(),
|
|
AttributeSet());
|
|
} else {
|
|
NewArgOperands.push_back(ACS.getCallArgOperand(OldArgNum));
|
|
NewArgOperandAttributes.push_back(
|
|
OldCallAttributeList.getParamAttributes(OldArgNum));
|
|
}
|
|
}
|
|
|
|
assert(NewArgOperands.size() == NewArgOperandAttributes.size() &&
|
|
"Mismatch # argument operands vs. # argument operand attributes!");
|
|
assert(NewArgOperands.size() == NewFn->arg_size() &&
|
|
"Mismatch # argument operands vs. # function arguments!");
|
|
|
|
SmallVector<OperandBundleDef, 4> OperandBundleDefs;
|
|
OldCB->getOperandBundlesAsDefs(OperandBundleDefs);
|
|
|
|
// Create a new call or invoke instruction to replace the old one.
|
|
CallBase *NewCB;
|
|
if (InvokeInst *II = dyn_cast<InvokeInst>(OldCB)) {
|
|
NewCB =
|
|
InvokeInst::Create(NewFn, II->getNormalDest(), II->getUnwindDest(),
|
|
NewArgOperands, OperandBundleDefs, "", OldCB);
|
|
} else {
|
|
auto *NewCI = CallInst::Create(NewFn, NewArgOperands, OperandBundleDefs,
|
|
"", OldCB);
|
|
NewCI->setTailCallKind(cast<CallInst>(OldCB)->getTailCallKind());
|
|
NewCB = NewCI;
|
|
}
|
|
|
|
// Copy over various properties and the new attributes.
|
|
NewCB->copyMetadata(*OldCB, {LLVMContext::MD_prof, LLVMContext::MD_dbg});
|
|
NewCB->setCallingConv(OldCB->getCallingConv());
|
|
NewCB->takeName(OldCB);
|
|
NewCB->setAttributes(AttributeList::get(
|
|
Ctx, OldCallAttributeList.getFnAttributes(),
|
|
OldCallAttributeList.getRetAttributes(), NewArgOperandAttributes));
|
|
|
|
CallSitePairs.push_back({OldCB, NewCB});
|
|
return true;
|
|
};
|
|
|
|
// Use the CallSiteReplacementCreator to create replacement call sites.
|
|
bool AllCallSitesKnown;
|
|
bool Success = checkForAllCallSites(CallSiteReplacementCreator, *OldFn,
|
|
true, nullptr, AllCallSitesKnown);
|
|
(void)Success;
|
|
assert(Success && "Assumed call site replacement to succeed!");
|
|
|
|
// Rewire the arguments.
|
|
Argument *OldFnArgIt = OldFn->arg_begin();
|
|
Argument *NewFnArgIt = NewFn->arg_begin();
|
|
for (unsigned OldArgNum = 0; OldArgNum < ARIs.size();
|
|
++OldArgNum, ++OldFnArgIt) {
|
|
if (const std::unique_ptr<ArgumentReplacementInfo> &ARI =
|
|
ARIs[OldArgNum]) {
|
|
if (ARI->CalleeRepairCB)
|
|
ARI->CalleeRepairCB(*ARI, *NewFn, NewFnArgIt);
|
|
NewFnArgIt += ARI->ReplacementTypes.size();
|
|
} else {
|
|
NewFnArgIt->takeName(&*OldFnArgIt);
|
|
OldFnArgIt->replaceAllUsesWith(&*NewFnArgIt);
|
|
++NewFnArgIt;
|
|
}
|
|
}
|
|
|
|
// Eliminate the instructions *after* we visited all of them.
|
|
for (auto &CallSitePair : CallSitePairs) {
|
|
CallBase &OldCB = *CallSitePair.first;
|
|
CallBase &NewCB = *CallSitePair.second;
|
|
assert(OldCB.getType() == NewCB.getType() &&
|
|
"Cannot handle call sites with different types!");
|
|
ModifiedFns.insert(OldCB.getFunction());
|
|
CGUpdater.replaceCallSite(OldCB, NewCB);
|
|
OldCB.replaceAllUsesWith(&NewCB);
|
|
OldCB.eraseFromParent();
|
|
}
|
|
|
|
// Replace the function in the call graph (if any).
|
|
CGUpdater.replaceFunctionWith(*OldFn, *NewFn);
|
|
|
|
// If the old function was modified and needed to be reanalyzed, the new one
|
|
// does now.
|
|
if (ModifiedFns.erase(OldFn))
|
|
ModifiedFns.insert(NewFn);
|
|
|
|
Changed = ChangeStatus::CHANGED;
|
|
}
|
|
|
|
return Changed;
|
|
}
|
|
|
|
void InformationCache::initializeInformationCache(const Function &CF,
|
|
FunctionInfo &FI) {
|
|
// As we do not modify the function here we can remove the const
|
|
// withouth breaking implicit assumptions. At the end of the day, we could
|
|
// initialize the cache eagerly which would look the same to the users.
|
|
Function &F = const_cast<Function &>(CF);
|
|
|
|
// Walk all instructions to find interesting instructions that might be
|
|
// queried by abstract attributes during their initialization or update.
|
|
// This has to happen before we create attributes.
|
|
|
|
for (Instruction &I : instructions(&F)) {
|
|
bool IsInterestingOpcode = false;
|
|
|
|
// To allow easy access to all instructions in a function with a given
|
|
// opcode we store them in the InfoCache. As not all opcodes are interesting
|
|
// to concrete attributes we only cache the ones that are as identified in
|
|
// the following switch.
|
|
// Note: There are no concrete attributes now so this is initially empty.
|
|
switch (I.getOpcode()) {
|
|
default:
|
|
assert(!isa<CallBase>(&I) &&
|
|
"New call base instruction type needs to be known in the "
|
|
"Attributor.");
|
|
break;
|
|
case Instruction::Call:
|
|
// Calls are interesting on their own, additionally:
|
|
// For `llvm.assume` calls we also fill the KnowledgeMap as we find them.
|
|
// For `must-tail` calls we remember the caller and callee.
|
|
if (IntrinsicInst *Assume = dyn_cast<IntrinsicInst>(&I)) {
|
|
if (Assume->getIntrinsicID() == Intrinsic::assume)
|
|
fillMapFromAssume(*Assume, KnowledgeMap);
|
|
} else if (cast<CallInst>(I).isMustTailCall()) {
|
|
FI.ContainsMustTailCall = true;
|
|
if (const Function *Callee = cast<CallInst>(I).getCalledFunction())
|
|
getFunctionInfo(*Callee).CalledViaMustTail = true;
|
|
}
|
|
LLVM_FALLTHROUGH;
|
|
case Instruction::CallBr:
|
|
case Instruction::Invoke:
|
|
case Instruction::CleanupRet:
|
|
case Instruction::CatchSwitch:
|
|
case Instruction::AtomicRMW:
|
|
case Instruction::AtomicCmpXchg:
|
|
case Instruction::Br:
|
|
case Instruction::Resume:
|
|
case Instruction::Ret:
|
|
case Instruction::Load:
|
|
// The alignment of a pointer is interesting for loads.
|
|
case Instruction::Store:
|
|
// The alignment of a pointer is interesting for stores.
|
|
IsInterestingOpcode = true;
|
|
}
|
|
if (IsInterestingOpcode) {
|
|
auto *&Insts = FI.OpcodeInstMap[I.getOpcode()];
|
|
if (!Insts)
|
|
Insts = new (Allocator) InstructionVectorTy();
|
|
Insts->push_back(&I);
|
|
}
|
|
if (I.mayReadOrWriteMemory())
|
|
FI.RWInsts.push_back(&I);
|
|
}
|
|
|
|
if (F.hasFnAttribute(Attribute::AlwaysInline) &&
|
|
isInlineViable(F).isSuccess())
|
|
InlineableFunctions.insert(&F);
|
|
}
|
|
|
|
InformationCache::FunctionInfo::~FunctionInfo() {
|
|
// The instruction vectors are allocated using a BumpPtrAllocator, we need to
|
|
// manually destroy them.
|
|
for (auto &It : OpcodeInstMap)
|
|
It.getSecond()->~InstructionVectorTy();
|
|
}
|
|
|
|
void Attributor::recordDependence(const AbstractAttribute &FromAA,
|
|
const AbstractAttribute &ToAA,
|
|
DepClassTy DepClass) {
|
|
// If we are outside of an update, thus before the actual fixpoint iteration
|
|
// started (= when we create AAs), we do not track dependences because we will
|
|
// put all AAs into the initial worklist anyway.
|
|
if (DependenceStack.empty())
|
|
return;
|
|
if (FromAA.getState().isAtFixpoint())
|
|
return;
|
|
DependenceStack.back()->push_back({&FromAA, &ToAA, DepClass});
|
|
}
|
|
|
|
void Attributor::rememberDependences() {
|
|
assert(!DependenceStack.empty() && "No dependences to remember!");
|
|
|
|
for (DepInfo &DI : *DependenceStack.back()) {
|
|
auto &DepAAs = const_cast<AbstractAttribute &>(*DI.FromAA).Deps;
|
|
DepAAs.push_back(AbstractAttribute::DepTy(
|
|
const_cast<AbstractAttribute *>(DI.ToAA), unsigned(DI.DepClass)));
|
|
}
|
|
}
|
|
|
|
void Attributor::identifyDefaultAbstractAttributes(Function &F) {
|
|
if (!VisitedFunctions.insert(&F).second)
|
|
return;
|
|
if (F.isDeclaration())
|
|
return;
|
|
|
|
// In non-module runs we need to look at the call sites of a function to
|
|
// determine if it is part of a must-tail call edge. This will influence what
|
|
// attributes we can derive.
|
|
InformationCache::FunctionInfo &FI = InfoCache.getFunctionInfo(F);
|
|
if (!isModulePass() && !FI.CalledViaMustTail) {
|
|
for (const Use &U : F.uses())
|
|
if (const auto *CB = dyn_cast<CallBase>(U.getUser()))
|
|
if (CB->isCallee(&U) && CB->isMustTailCall())
|
|
FI.CalledViaMustTail = true;
|
|
}
|
|
|
|
IRPosition FPos = IRPosition::function(F);
|
|
|
|
// Check for dead BasicBlocks in every function.
|
|
// We need dead instruction detection because we do not want to deal with
|
|
// broken IR in which SSA rules do not apply.
|
|
getOrCreateAAFor<AAIsDead>(FPos);
|
|
|
|
// Every function might be "will-return".
|
|
getOrCreateAAFor<AAWillReturn>(FPos);
|
|
|
|
// Every function might contain instructions that cause "undefined behavior".
|
|
getOrCreateAAFor<AAUndefinedBehavior>(FPos);
|
|
|
|
// Every function can be nounwind.
|
|
getOrCreateAAFor<AANoUnwind>(FPos);
|
|
|
|
// Every function might be marked "nosync"
|
|
getOrCreateAAFor<AANoSync>(FPos);
|
|
|
|
// Every function might be "no-free".
|
|
getOrCreateAAFor<AANoFree>(FPos);
|
|
|
|
// Every function might be "no-return".
|
|
getOrCreateAAFor<AANoReturn>(FPos);
|
|
|
|
// Every function might be "no-recurse".
|
|
getOrCreateAAFor<AANoRecurse>(FPos);
|
|
|
|
// Every function might be "readnone/readonly/writeonly/...".
|
|
getOrCreateAAFor<AAMemoryBehavior>(FPos);
|
|
|
|
// Every function can be "readnone/argmemonly/inaccessiblememonly/...".
|
|
getOrCreateAAFor<AAMemoryLocation>(FPos);
|
|
|
|
// Every function might be applicable for Heap-To-Stack conversion.
|
|
if (EnableHeapToStack)
|
|
getOrCreateAAFor<AAHeapToStack>(FPos);
|
|
|
|
// Return attributes are only appropriate if the return type is non void.
|
|
Type *ReturnType = F.getReturnType();
|
|
if (!ReturnType->isVoidTy()) {
|
|
// Argument attribute "returned" --- Create only one per function even
|
|
// though it is an argument attribute.
|
|
getOrCreateAAFor<AAReturnedValues>(FPos);
|
|
|
|
IRPosition RetPos = IRPosition::returned(F);
|
|
|
|
// Every returned value might be dead.
|
|
getOrCreateAAFor<AAIsDead>(RetPos);
|
|
|
|
// Every function might be simplified.
|
|
getOrCreateAAFor<AAValueSimplify>(RetPos);
|
|
|
|
// Every returned value might be marked noundef.
|
|
getOrCreateAAFor<AANoUndef>(RetPos);
|
|
|
|
if (ReturnType->isPointerTy()) {
|
|
|
|
// Every function with pointer return type might be marked align.
|
|
getOrCreateAAFor<AAAlign>(RetPos);
|
|
|
|
// Every function with pointer return type might be marked nonnull.
|
|
getOrCreateAAFor<AANonNull>(RetPos);
|
|
|
|
// Every function with pointer return type might be marked noalias.
|
|
getOrCreateAAFor<AANoAlias>(RetPos);
|
|
|
|
// Every function with pointer return type might be marked
|
|
// dereferenceable.
|
|
getOrCreateAAFor<AADereferenceable>(RetPos);
|
|
}
|
|
}
|
|
|
|
for (Argument &Arg : F.args()) {
|
|
IRPosition ArgPos = IRPosition::argument(Arg);
|
|
|
|
// Every argument might be simplified.
|
|
getOrCreateAAFor<AAValueSimplify>(ArgPos);
|
|
|
|
// Every argument might be dead.
|
|
getOrCreateAAFor<AAIsDead>(ArgPos);
|
|
|
|
// Every argument might be marked noundef.
|
|
getOrCreateAAFor<AANoUndef>(ArgPos);
|
|
|
|
if (Arg.getType()->isPointerTy()) {
|
|
// Every argument with pointer type might be marked nonnull.
|
|
getOrCreateAAFor<AANonNull>(ArgPos);
|
|
|
|
// Every argument with pointer type might be marked noalias.
|
|
getOrCreateAAFor<AANoAlias>(ArgPos);
|
|
|
|
// Every argument with pointer type might be marked dereferenceable.
|
|
getOrCreateAAFor<AADereferenceable>(ArgPos);
|
|
|
|
// Every argument with pointer type might be marked align.
|
|
getOrCreateAAFor<AAAlign>(ArgPos);
|
|
|
|
// Every argument with pointer type might be marked nocapture.
|
|
getOrCreateAAFor<AANoCapture>(ArgPos);
|
|
|
|
// Every argument with pointer type might be marked
|
|
// "readnone/readonly/writeonly/..."
|
|
getOrCreateAAFor<AAMemoryBehavior>(ArgPos);
|
|
|
|
// Every argument with pointer type might be marked nofree.
|
|
getOrCreateAAFor<AANoFree>(ArgPos);
|
|
|
|
// Every argument with pointer type might be privatizable (or promotable)
|
|
getOrCreateAAFor<AAPrivatizablePtr>(ArgPos);
|
|
}
|
|
}
|
|
|
|
auto CallSitePred = [&](Instruction &I) -> bool {
|
|
auto &CB = cast<CallBase>(I);
|
|
IRPosition CBRetPos = IRPosition::callsite_returned(CB);
|
|
|
|
// Call sites might be dead if they do not have side effects and no live
|
|
// users. The return value might be dead if there are no live users.
|
|
getOrCreateAAFor<AAIsDead>(CBRetPos);
|
|
|
|
Function *Callee = CB.getCalledFunction();
|
|
// TODO: Even if the callee is not known now we might be able to simplify
|
|
// the call/callee.
|
|
if (!Callee)
|
|
return true;
|
|
|
|
// Skip declarations except if annotations on their call sites were
|
|
// explicitly requested.
|
|
if (!AnnotateDeclarationCallSites && Callee->isDeclaration() &&
|
|
!Callee->hasMetadata(LLVMContext::MD_callback))
|
|
return true;
|
|
|
|
if (!Callee->getReturnType()->isVoidTy() && !CB.use_empty()) {
|
|
|
|
IRPosition CBRetPos = IRPosition::callsite_returned(CB);
|
|
|
|
// Call site return integer values might be limited by a constant range.
|
|
if (Callee->getReturnType()->isIntegerTy())
|
|
getOrCreateAAFor<AAValueConstantRange>(CBRetPos);
|
|
}
|
|
|
|
for (int I = 0, E = CB.getNumArgOperands(); I < E; ++I) {
|
|
|
|
IRPosition CBArgPos = IRPosition::callsite_argument(CB, I);
|
|
|
|
// Every call site argument might be dead.
|
|
getOrCreateAAFor<AAIsDead>(CBArgPos);
|
|
|
|
// Call site argument might be simplified.
|
|
getOrCreateAAFor<AAValueSimplify>(CBArgPos);
|
|
|
|
// Every call site argument might be marked "noundef".
|
|
getOrCreateAAFor<AANoUndef>(CBArgPos);
|
|
|
|
if (!CB.getArgOperand(I)->getType()->isPointerTy())
|
|
continue;
|
|
|
|
// Call site argument attribute "non-null".
|
|
getOrCreateAAFor<AANonNull>(CBArgPos);
|
|
|
|
// Call site argument attribute "nocapture".
|
|
getOrCreateAAFor<AANoCapture>(CBArgPos);
|
|
|
|
// Call site argument attribute "no-alias".
|
|
getOrCreateAAFor<AANoAlias>(CBArgPos);
|
|
|
|
// Call site argument attribute "dereferenceable".
|
|
getOrCreateAAFor<AADereferenceable>(CBArgPos);
|
|
|
|
// Call site argument attribute "align".
|
|
getOrCreateAAFor<AAAlign>(CBArgPos);
|
|
|
|
// Call site argument attribute
|
|
// "readnone/readonly/writeonly/..."
|
|
getOrCreateAAFor<AAMemoryBehavior>(CBArgPos);
|
|
|
|
// Call site argument attribute "nofree".
|
|
getOrCreateAAFor<AANoFree>(CBArgPos);
|
|
}
|
|
return true;
|
|
};
|
|
|
|
auto &OpcodeInstMap = InfoCache.getOpcodeInstMapForFunction(F);
|
|
bool Success;
|
|
Success = checkForAllInstructionsImpl(
|
|
nullptr, OpcodeInstMap, CallSitePred, nullptr, nullptr,
|
|
{(unsigned)Instruction::Invoke, (unsigned)Instruction::CallBr,
|
|
(unsigned)Instruction::Call});
|
|
(void)Success;
|
|
assert(Success && "Expected the check call to be successful!");
|
|
|
|
auto LoadStorePred = [&](Instruction &I) -> bool {
|
|
if (isa<LoadInst>(I))
|
|
getOrCreateAAFor<AAAlign>(
|
|
IRPosition::value(*cast<LoadInst>(I).getPointerOperand()));
|
|
else
|
|
getOrCreateAAFor<AAAlign>(
|
|
IRPosition::value(*cast<StoreInst>(I).getPointerOperand()));
|
|
return true;
|
|
};
|
|
Success = checkForAllInstructionsImpl(
|
|
nullptr, OpcodeInstMap, LoadStorePred, nullptr, nullptr,
|
|
{(unsigned)Instruction::Load, (unsigned)Instruction::Store});
|
|
(void)Success;
|
|
assert(Success && "Expected the check call to be successful!");
|
|
}
|
|
|
|
/// Helpers to ease debugging through output streams and print calls.
|
|
///
|
|
///{
|
|
raw_ostream &llvm::operator<<(raw_ostream &OS, ChangeStatus S) {
|
|
return OS << (S == ChangeStatus::CHANGED ? "changed" : "unchanged");
|
|
}
|
|
|
|
raw_ostream &llvm::operator<<(raw_ostream &OS, IRPosition::Kind AP) {
|
|
switch (AP) {
|
|
case IRPosition::IRP_INVALID:
|
|
return OS << "inv";
|
|
case IRPosition::IRP_FLOAT:
|
|
return OS << "flt";
|
|
case IRPosition::IRP_RETURNED:
|
|
return OS << "fn_ret";
|
|
case IRPosition::IRP_CALL_SITE_RETURNED:
|
|
return OS << "cs_ret";
|
|
case IRPosition::IRP_FUNCTION:
|
|
return OS << "fn";
|
|
case IRPosition::IRP_CALL_SITE:
|
|
return OS << "cs";
|
|
case IRPosition::IRP_ARGUMENT:
|
|
return OS << "arg";
|
|
case IRPosition::IRP_CALL_SITE_ARGUMENT:
|
|
return OS << "cs_arg";
|
|
}
|
|
llvm_unreachable("Unknown attribute position!");
|
|
}
|
|
|
|
raw_ostream &llvm::operator<<(raw_ostream &OS, const IRPosition &Pos) {
|
|
const Value &AV = Pos.getAssociatedValue();
|
|
return OS << "{" << Pos.getPositionKind() << ":" << AV.getName() << " ["
|
|
<< Pos.getAnchorValue().getName() << "@" << Pos.getCallSiteArgNo()
|
|
<< "]}";
|
|
}
|
|
|
|
raw_ostream &llvm::operator<<(raw_ostream &OS, const IntegerRangeState &S) {
|
|
OS << "range-state(" << S.getBitWidth() << ")<";
|
|
S.getKnown().print(OS);
|
|
OS << " / ";
|
|
S.getAssumed().print(OS);
|
|
OS << ">";
|
|
|
|
return OS << static_cast<const AbstractState &>(S);
|
|
}
|
|
|
|
raw_ostream &llvm::operator<<(raw_ostream &OS, const AbstractState &S) {
|
|
return OS << (!S.isValidState() ? "top" : (S.isAtFixpoint() ? "fix" : ""));
|
|
}
|
|
|
|
raw_ostream &llvm::operator<<(raw_ostream &OS, const AbstractAttribute &AA) {
|
|
AA.print(OS);
|
|
return OS;
|
|
}
|
|
|
|
raw_ostream &llvm::operator<<(raw_ostream &OS,
|
|
const PotentialConstantIntValuesState &S) {
|
|
OS << "set-state(< {";
|
|
if (!S.isValidState())
|
|
OS << "full-set";
|
|
else {
|
|
for (auto &it : S.getAssumedSet())
|
|
OS << it << ", ";
|
|
if (S.undefIsContained())
|
|
OS << "undef ";
|
|
}
|
|
OS << "} >)";
|
|
|
|
return OS;
|
|
}
|
|
|
|
void AbstractAttribute::print(raw_ostream &OS) const {
|
|
OS << "[";
|
|
OS << getName();
|
|
OS << "] for CtxI ";
|
|
|
|
if (auto *I = getCtxI()) {
|
|
OS << "'";
|
|
I->print(OS);
|
|
OS << "'";
|
|
} else
|
|
OS << "<<null inst>>";
|
|
|
|
OS << " at position " << getIRPosition() << " with state " << getAsStr()
|
|
<< '\n';
|
|
}
|
|
|
|
void AbstractAttribute::printWithDeps(raw_ostream &OS) const {
|
|
print(OS);
|
|
|
|
for (const auto &DepAA : Deps) {
|
|
auto *AA = DepAA.getPointer();
|
|
OS << " updates ";
|
|
AA->print(OS);
|
|
}
|
|
|
|
OS << '\n';
|
|
}
|
|
///}
|
|
|
|
/// ----------------------------------------------------------------------------
|
|
/// Pass (Manager) Boilerplate
|
|
/// ----------------------------------------------------------------------------
|
|
|
|
static bool runAttributorOnFunctions(InformationCache &InfoCache,
|
|
SetVector<Function *> &Functions,
|
|
AnalysisGetter &AG,
|
|
CallGraphUpdater &CGUpdater) {
|
|
if (Functions.empty())
|
|
return false;
|
|
|
|
LLVM_DEBUG(dbgs() << "[Attributor] Run on module with " << Functions.size()
|
|
<< " functions.\n");
|
|
|
|
// Create an Attributor and initially empty information cache that is filled
|
|
// while we identify default attribute opportunities.
|
|
Attributor A(Functions, InfoCache, CGUpdater);
|
|
|
|
// Create shallow wrappers for all functions that are not IPO amendable
|
|
if (AllowShallowWrappers)
|
|
for (Function *F : Functions)
|
|
if (!A.isFunctionIPOAmendable(*F))
|
|
Attributor::createShallowWrapper(*F);
|
|
|
|
// Internalize non-exact functions
|
|
// TODO: for now we eagerly internalize functions without calculating the
|
|
// cost, we need a cost interface to determine whether internalizing
|
|
// a function is "benefitial"
|
|
if (AllowDeepWrapper) {
|
|
unsigned FunSize = Functions.size();
|
|
for (unsigned u = 0; u < FunSize; u++) {
|
|
Function *F = Functions[u];
|
|
if (!F->isDeclaration() && !F->isDefinitionExact() && F->getNumUses() &&
|
|
!GlobalValue::isInterposableLinkage(F->getLinkage())) {
|
|
Function *NewF = internalizeFunction(*F);
|
|
Functions.insert(NewF);
|
|
|
|
// Update call graph
|
|
CGUpdater.replaceFunctionWith(*F, *NewF);
|
|
for (const Use &U : NewF->uses())
|
|
if (CallBase *CB = dyn_cast<CallBase>(U.getUser())) {
|
|
auto *CallerF = CB->getCaller();
|
|
CGUpdater.reanalyzeFunction(*CallerF);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
for (Function *F : Functions) {
|
|
if (F->hasExactDefinition())
|
|
NumFnWithExactDefinition++;
|
|
else
|
|
NumFnWithoutExactDefinition++;
|
|
|
|
// We look at internal functions only on-demand but if any use is not a
|
|
// direct call or outside the current set of analyzed functions, we have
|
|
// to do it eagerly.
|
|
if (F->hasLocalLinkage()) {
|
|
if (llvm::all_of(F->uses(), [&Functions](const Use &U) {
|
|
const auto *CB = dyn_cast<CallBase>(U.getUser());
|
|
return CB && CB->isCallee(&U) &&
|
|
Functions.count(const_cast<Function *>(CB->getCaller()));
|
|
}))
|
|
continue;
|
|
}
|
|
|
|
// Populate the Attributor with abstract attribute opportunities in the
|
|
// function and the information cache with IR information.
|
|
A.identifyDefaultAbstractAttributes(*F);
|
|
}
|
|
|
|
ChangeStatus Changed = A.run();
|
|
|
|
LLVM_DEBUG(dbgs() << "[Attributor] Done with " << Functions.size()
|
|
<< " functions, result: " << Changed << ".\n");
|
|
return Changed == ChangeStatus::CHANGED;
|
|
}
|
|
|
|
void AADepGraph::viewGraph() { llvm::ViewGraph(this, "Dependency Graph"); }
|
|
|
|
void AADepGraph::dumpGraph() {
|
|
static std::atomic<int> CallTimes;
|
|
std::string Prefix;
|
|
|
|
if (!DepGraphDotFileNamePrefix.empty())
|
|
Prefix = DepGraphDotFileNamePrefix;
|
|
else
|
|
Prefix = "dep_graph";
|
|
std::string Filename =
|
|
Prefix + "_" + std::to_string(CallTimes.load()) + ".dot";
|
|
|
|
outs() << "Dependency graph dump to " << Filename << ".\n";
|
|
|
|
std::error_code EC;
|
|
|
|
raw_fd_ostream File(Filename, EC, sys::fs::OF_Text);
|
|
if (!EC)
|
|
llvm::WriteGraph(File, this);
|
|
|
|
CallTimes++;
|
|
}
|
|
|
|
void AADepGraph::print() {
|
|
for (auto DepAA : SyntheticRoot.Deps)
|
|
cast<AbstractAttribute>(DepAA.getPointer())->printWithDeps(outs());
|
|
}
|
|
|
|
PreservedAnalyses AttributorPass::run(Module &M, ModuleAnalysisManager &AM) {
|
|
FunctionAnalysisManager &FAM =
|
|
AM.getResult<FunctionAnalysisManagerModuleProxy>(M).getManager();
|
|
AnalysisGetter AG(FAM);
|
|
|
|
SetVector<Function *> Functions;
|
|
for (Function &F : M)
|
|
Functions.insert(&F);
|
|
|
|
CallGraphUpdater CGUpdater;
|
|
BumpPtrAllocator Allocator;
|
|
InformationCache InfoCache(M, AG, Allocator, /* CGSCC */ nullptr);
|
|
if (runAttributorOnFunctions(InfoCache, Functions, AG, CGUpdater)) {
|
|
// FIXME: Think about passes we will preserve and add them here.
|
|
return PreservedAnalyses::none();
|
|
}
|
|
return PreservedAnalyses::all();
|
|
}
|
|
|
|
PreservedAnalyses AttributorCGSCCPass::run(LazyCallGraph::SCC &C,
|
|
CGSCCAnalysisManager &AM,
|
|
LazyCallGraph &CG,
|
|
CGSCCUpdateResult &UR) {
|
|
FunctionAnalysisManager &FAM =
|
|
AM.getResult<FunctionAnalysisManagerCGSCCProxy>(C, CG).getManager();
|
|
AnalysisGetter AG(FAM);
|
|
|
|
SetVector<Function *> Functions;
|
|
for (LazyCallGraph::Node &N : C)
|
|
Functions.insert(&N.getFunction());
|
|
|
|
if (Functions.empty())
|
|
return PreservedAnalyses::all();
|
|
|
|
Module &M = *Functions.back()->getParent();
|
|
CallGraphUpdater CGUpdater;
|
|
CGUpdater.initialize(CG, C, AM, UR);
|
|
BumpPtrAllocator Allocator;
|
|
InformationCache InfoCache(M, AG, Allocator, /* CGSCC */ &Functions);
|
|
if (runAttributorOnFunctions(InfoCache, Functions, AG, CGUpdater)) {
|
|
// FIXME: Think about passes we will preserve and add them here.
|
|
PreservedAnalyses PA;
|
|
PA.preserve<FunctionAnalysisManagerCGSCCProxy>();
|
|
return PA;
|
|
}
|
|
return PreservedAnalyses::all();
|
|
}
|
|
|
|
namespace llvm {
|
|
|
|
template <> struct GraphTraits<AADepGraphNode *> {
|
|
using NodeRef = AADepGraphNode *;
|
|
using DepTy = PointerIntPair<AADepGraphNode *, 1>;
|
|
using EdgeRef = PointerIntPair<AADepGraphNode *, 1>;
|
|
|
|
static NodeRef getEntryNode(AADepGraphNode *DGN) { return DGN; }
|
|
static NodeRef DepGetVal(DepTy &DT) { return DT.getPointer(); }
|
|
|
|
using ChildIteratorType =
|
|
mapped_iterator<TinyPtrVector<DepTy>::iterator, decltype(&DepGetVal)>;
|
|
using ChildEdgeIteratorType = TinyPtrVector<DepTy>::iterator;
|
|
|
|
static ChildIteratorType child_begin(NodeRef N) { return N->child_begin(); }
|
|
|
|
static ChildIteratorType child_end(NodeRef N) { return N->child_end(); }
|
|
};
|
|
|
|
template <>
|
|
struct GraphTraits<AADepGraph *> : public GraphTraits<AADepGraphNode *> {
|
|
static NodeRef getEntryNode(AADepGraph *DG) { return DG->GetEntryNode(); }
|
|
|
|
using nodes_iterator =
|
|
mapped_iterator<TinyPtrVector<DepTy>::iterator, decltype(&DepGetVal)>;
|
|
|
|
static nodes_iterator nodes_begin(AADepGraph *DG) { return DG->begin(); }
|
|
|
|
static nodes_iterator nodes_end(AADepGraph *DG) { return DG->end(); }
|
|
};
|
|
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template <> struct DOTGraphTraits<AADepGraph *> : public DefaultDOTGraphTraits {
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DOTGraphTraits(bool isSimple = false) : DefaultDOTGraphTraits(isSimple) {}
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static std::string getNodeLabel(const AADepGraphNode *Node,
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const AADepGraph *DG) {
|
|
std::string AAString = "";
|
|
raw_string_ostream O(AAString);
|
|
Node->print(O);
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|
return AAString;
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}
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};
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|
|
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} // end namespace llvm
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|
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namespace {
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|
|
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struct AttributorLegacyPass : public ModulePass {
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static char ID;
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|
|
|
AttributorLegacyPass() : ModulePass(ID) {
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initializeAttributorLegacyPassPass(*PassRegistry::getPassRegistry());
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|
}
|
|
|
|
bool runOnModule(Module &M) override {
|
|
if (skipModule(M))
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|
return false;
|
|
|
|
AnalysisGetter AG;
|
|
SetVector<Function *> Functions;
|
|
for (Function &F : M)
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|
Functions.insert(&F);
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|
|
|
CallGraphUpdater CGUpdater;
|
|
BumpPtrAllocator Allocator;
|
|
InformationCache InfoCache(M, AG, Allocator, /* CGSCC */ nullptr);
|
|
return runAttributorOnFunctions(InfoCache, Functions, AG, CGUpdater);
|
|
}
|
|
|
|
void getAnalysisUsage(AnalysisUsage &AU) const override {
|
|
// FIXME: Think about passes we will preserve and add them here.
|
|
AU.addRequired<TargetLibraryInfoWrapperPass>();
|
|
}
|
|
};
|
|
|
|
struct AttributorCGSCCLegacyPass : public CallGraphSCCPass {
|
|
CallGraphUpdater CGUpdater;
|
|
static char ID;
|
|
|
|
AttributorCGSCCLegacyPass() : CallGraphSCCPass(ID) {
|
|
initializeAttributorCGSCCLegacyPassPass(*PassRegistry::getPassRegistry());
|
|
}
|
|
|
|
bool runOnSCC(CallGraphSCC &SCC) override {
|
|
if (skipSCC(SCC))
|
|
return false;
|
|
|
|
SetVector<Function *> Functions;
|
|
for (CallGraphNode *CGN : SCC)
|
|
if (Function *Fn = CGN->getFunction())
|
|
if (!Fn->isDeclaration())
|
|
Functions.insert(Fn);
|
|
|
|
if (Functions.empty())
|
|
return false;
|
|
|
|
AnalysisGetter AG;
|
|
CallGraph &CG = const_cast<CallGraph &>(SCC.getCallGraph());
|
|
CGUpdater.initialize(CG, SCC);
|
|
Module &M = *Functions.back()->getParent();
|
|
BumpPtrAllocator Allocator;
|
|
InformationCache InfoCache(M, AG, Allocator, /* CGSCC */ &Functions);
|
|
return runAttributorOnFunctions(InfoCache, Functions, AG, CGUpdater);
|
|
}
|
|
|
|
bool doFinalization(CallGraph &CG) override { return CGUpdater.finalize(); }
|
|
|
|
void getAnalysisUsage(AnalysisUsage &AU) const override {
|
|
// FIXME: Think about passes we will preserve and add them here.
|
|
AU.addRequired<TargetLibraryInfoWrapperPass>();
|
|
CallGraphSCCPass::getAnalysisUsage(AU);
|
|
}
|
|
};
|
|
|
|
} // end anonymous namespace
|
|
|
|
Pass *llvm::createAttributorLegacyPass() { return new AttributorLegacyPass(); }
|
|
Pass *llvm::createAttributorCGSCCLegacyPass() {
|
|
return new AttributorCGSCCLegacyPass();
|
|
}
|
|
|
|
char AttributorLegacyPass::ID = 0;
|
|
char AttributorCGSCCLegacyPass::ID = 0;
|
|
|
|
INITIALIZE_PASS_BEGIN(AttributorLegacyPass, "attributor",
|
|
"Deduce and propagate attributes", false, false)
|
|
INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
|
|
INITIALIZE_PASS_END(AttributorLegacyPass, "attributor",
|
|
"Deduce and propagate attributes", false, false)
|
|
INITIALIZE_PASS_BEGIN(AttributorCGSCCLegacyPass, "attributor-cgscc",
|
|
"Deduce and propagate attributes (CGSCC pass)", false,
|
|
false)
|
|
INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
|
|
INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)
|
|
INITIALIZE_PASS_END(AttributorCGSCCLegacyPass, "attributor-cgscc",
|
|
"Deduce and propagate attributes (CGSCC pass)", false,
|
|
false)
|