9849291dcc
Encoding FS discriminators for block probes. Decoding them correspondingly. The encoding/decoding of FS discriminators are conditional, only for probes with a non-zero discriminator. This saves encoding size, also ensures downwards-compatiblity. Reviewed By: wenlei Differential Revision: https://reviews.llvm.org/D147651
55 lines
2.4 KiB
C++
55 lines
2.4 KiB
C++
//===- llvm/CodeGen/PseudoProbePrinter.cpp - Pseudo Probe Emission -------===//
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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 contains support for writing pseudo probe info into asm files.
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//
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//===----------------------------------------------------------------------===//
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#include "PseudoProbePrinter.h"
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#include "llvm/CodeGen/AsmPrinter.h"
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#include "llvm/IR/DebugInfoMetadata.h"
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#include "llvm/IR/Function.h"
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#include "llvm/IR/PseudoProbe.h"
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#include "llvm/MC/MCPseudoProbe.h"
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#include "llvm/MC/MCStreamer.h"
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using namespace llvm;
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PseudoProbeHandler::~PseudoProbeHandler() = default;
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void PseudoProbeHandler::emitPseudoProbe(uint64_t Guid, uint64_t Index,
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uint64_t Type, uint64_t Attr,
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const DILocation *DebugLoc) {
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// Gather all the inlined-at nodes.
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// When it's done ReversedInlineStack looks like ([66, B], [88, A])
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// which means, Function A inlines function B at calliste with a probe id 88,
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// and B inlines C at probe 66 where C is represented by Guid.
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SmallVector<InlineSite, 8> ReversedInlineStack;
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auto *InlinedAt = DebugLoc ? DebugLoc->getInlinedAt() : nullptr;
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while (InlinedAt) {
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auto Name = InlinedAt->getSubprogramLinkageName();
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// Use caching to avoid redundant md5 computation for build speed.
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uint64_t &CallerGuid = NameGuidMap[Name];
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if (!CallerGuid)
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CallerGuid = Function::getGUID(Name);
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uint64_t CallerProbeId = PseudoProbeDwarfDiscriminator::extractProbeIndex(
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InlinedAt->getDiscriminator());
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ReversedInlineStack.emplace_back(CallerGuid, CallerProbeId);
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InlinedAt = InlinedAt->getInlinedAt();
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}
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uint64_t Discriminator = 0;
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// For now only block probes have FS discriminators. See
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// MIRFSDiscriminator.cpp for more details.
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if (DebugLoc &&
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!DILocation::isPseudoProbeDiscriminator(DebugLoc->getDiscriminator()))
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Discriminator = DebugLoc->getDiscriminator();
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SmallVector<InlineSite, 8> InlineStack(llvm::reverse(ReversedInlineStack));
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Asm->OutStreamer->emitPseudoProbe(Guid, Index, Type, Attr, Discriminator,
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InlineStack, Asm->CurrentFnSym);
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}
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