1 | //===- llvm/CodeGen/PseudoProbePrinter.cpp - Pseudo Probe Emission -------===// |
2 | // |
3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
4 | // See https://llvm.org/LICENSE.txt for license information. |
5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
6 | // |
7 | //===----------------------------------------------------------------------===// |
8 | // |
9 | // This file contains support for writing pseudo probe info into asm files. |
10 | // |
11 | //===----------------------------------------------------------------------===// |
12 | |
13 | #include "PseudoProbePrinter.h" |
14 | #include "llvm/CodeGen/AsmPrinter.h" |
15 | #include "llvm/IR/DebugInfoMetadata.h" |
16 | #include "llvm/IR/Function.h" |
17 | #include "llvm/IR/PseudoProbe.h" |
18 | #include "llvm/MC/MCPseudoProbe.h" |
19 | #include "llvm/MC/MCStreamer.h" |
20 | |
21 | using namespace llvm; |
22 | |
23 | PseudoProbeHandler::~PseudoProbeHandler() = default; |
24 | |
25 | void PseudoProbeHandler::emitPseudoProbe(uint64_t Guid, uint64_t Index, |
26 | uint64_t Type, uint64_t Attr, |
27 | const DILocation *DebugLoc) { |
28 | // Gather all the inlined-at nodes. |
29 | // When it's done ReversedInlineStack looks like ([66, B], [88, A]) |
30 | // which means, Function A inlines function B at calliste with a probe id 88, |
31 | // and B inlines C at probe 66 where C is represented by Guid. |
32 | SmallVector<InlineSite, 8> ReversedInlineStack; |
33 | auto *InlinedAt = DebugLoc ? DebugLoc->getInlinedAt() : nullptr; |
34 | while (InlinedAt) { |
35 | auto Name = InlinedAt->getSubprogramLinkageName(); |
36 | // Use caching to avoid redundant md5 computation for build speed. |
37 | uint64_t &CallerGuid = NameGuidMap[Name]; |
38 | if (!CallerGuid) |
39 | CallerGuid = Function::getGUID(GlobalName: Name); |
40 | uint64_t CallerProbeId = PseudoProbeDwarfDiscriminator::extractProbeIndex( |
41 | Value: InlinedAt->getDiscriminator()); |
42 | ReversedInlineStack.emplace_back(Args&: CallerGuid, Args&: CallerProbeId); |
43 | InlinedAt = InlinedAt->getInlinedAt(); |
44 | } |
45 | uint64_t Discriminator = 0; |
46 | // For now only block probes have FS discriminators. See |
47 | // MIRFSDiscriminator.cpp for more details. |
48 | if (EnableFSDiscriminator && DebugLoc && |
49 | (Type == (uint64_t)PseudoProbeType::Block)) |
50 | Discriminator = DebugLoc->getDiscriminator(); |
51 | assert((EnableFSDiscriminator || Discriminator == 0) && |
52 | "Discriminator should not be set in non-FSAFDO mode" ); |
53 | SmallVector<InlineSite, 8> InlineStack(llvm::reverse(C&: ReversedInlineStack)); |
54 | Asm->OutStreamer->emitPseudoProbe(Guid, Index, Type, Attr, Discriminator, |
55 | InlineStack, FnSym: Asm->CurrentFnSym); |
56 | } |
57 | |