1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
|
//===----------------------- CodeRegionGenerator.cpp ------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
/// \file
///
/// This file defines classes responsible for generating llvm-mca
/// CodeRegions from various types of input. llvm-mca only analyzes CodeRegions,
/// so the classes here provide the input-to-CodeRegions translation.
//
//===----------------------------------------------------------------------===//
#include "CodeRegionGenerator.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/MC/MCParser/MCTargetAsmParser.h"
#include "llvm/MC/MCTargetOptions.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/SMLoc.h"
#include <memory>
namespace llvm {
namespace mca {
// This virtual dtor serves as the anchor for the CodeRegionGenerator class.
CodeRegionGenerator::~CodeRegionGenerator() {}
Expected<const CodeRegions &> AsmCodeRegionGenerator::parseCodeRegions(
const std::unique_ptr<MCInstPrinter> &IP, bool SkipFailures) {
MCTargetOptions Opts;
Opts.PreserveAsmComments = false;
CodeRegions &Regions = getRegions();
MCStreamerWrapper *Str = getMCStreamer();
// Need to initialize an MCTargetStreamer otherwise
// certain asm directives will cause a segfault.
// Using nulls() so that anything emitted by the MCTargetStreamer
// doesn't show up in the llvm-mca output.
raw_ostream &OSRef = nulls();
formatted_raw_ostream FOSRef(OSRef);
TheTarget.createAsmTargetStreamer(*Str, FOSRef, IP.get());
// Create a MCAsmParser and setup the lexer to recognize llvm-mca ASM
// comments.
std::unique_ptr<MCAsmParser> Parser(
createMCAsmParser(Regions.getSourceMgr(), Ctx, *Str, MAI));
MCAsmLexer &Lexer = Parser->getLexer();
MCACommentConsumer *CCP = getCommentConsumer();
Lexer.setCommentConsumer(CCP);
// Enable support for MASM literal numbers (example: 05h, 101b).
Lexer.setLexMasmIntegers(true);
std::unique_ptr<MCTargetAsmParser> TAP(
TheTarget.createMCAsmParser(STI, *Parser, MCII, Opts));
if (!TAP)
return make_error<StringError>(
"This target does not support assembly parsing.",
inconvertibleErrorCode());
Parser->setTargetParser(*TAP);
// Parser->Run() confusingly returns true on errors, in which case the errors
// were already shown to the user. SkipFailures implies continuing in the
// presence of any kind of failure within the parser, in which case failing
// input lines are not represented, but the rest of the input remains.
if (Parser->Run(false) && !SkipFailures) {
const char *Message = "Assembly input parsing had errors, use "
"-skip-unsupported-instructions=parse-failure "
"to drop failing lines from the input.";
return make_error<StringError>(Message, inconvertibleErrorCode());
}
if (CCP->hadErr())
return make_error<StringError>("There was an error parsing comments.",
inconvertibleErrorCode());
// Set the assembler dialect from the input. llvm-mca will use this as the
// default dialect when printing reports.
AssemblerDialect = Parser->getAssemblerDialect();
return Regions;
}
void AnalysisRegionCommentConsumer::HandleComment(SMLoc Loc,
StringRef CommentText) {
// Skip empty comments.
StringRef Comment(CommentText);
if (Comment.empty())
return;
// Skip spaces and tabs.
unsigned Position = Comment.find_first_not_of(" \t");
if (Position >= Comment.size())
// We reached the end of the comment. Bail out.
return;
Comment = Comment.drop_front(Position);
if (Comment.consume_front("LLVM-MCA-END")) {
// Skip spaces and tabs.
Position = Comment.find_first_not_of(" \t");
if (Position < Comment.size())
Comment = Comment.drop_front(Position);
Regions.endRegion(Comment, Loc);
return;
}
// Try to parse the LLVM-MCA-BEGIN comment.
if (!Comment.consume_front("LLVM-MCA-BEGIN"))
return;
// Skip spaces and tabs.
Position = Comment.find_first_not_of(" \t");
if (Position < Comment.size())
Comment = Comment.drop_front(Position);
// Use the rest of the string as a descriptor for this code snippet.
Regions.beginRegion(Comment, Loc);
}
void InstrumentRegionCommentConsumer::HandleComment(SMLoc Loc,
StringRef CommentText) {
// Skip empty comments.
StringRef Comment(CommentText);
if (Comment.empty())
return;
// Skip spaces and tabs.
unsigned Position = Comment.find_first_not_of(" \t");
if (Position >= Comment.size())
// We reached the end of the comment. Bail out.
return;
Comment = Comment.drop_front(Position);
// Bail out if not an MCA style comment
if (!Comment.consume_front("LLVM-MCA-"))
return;
// Skip AnalysisRegion comments
if (Comment.consume_front("BEGIN") || Comment.consume_front("END"))
return;
if (IM.shouldIgnoreInstruments())
return;
auto [InstrumentKind, Data] = Comment.split(" ");
// An error if not of the form LLVM-MCA-TARGET-KIND
if (!IM.supportsInstrumentType(InstrumentKind)) {
if (InstrumentKind.empty())
SM.PrintMessage(
Loc, llvm::SourceMgr::DK_Error,
"No instrumentation kind was provided in LLVM-MCA comment");
else
SM.PrintMessage(Loc, llvm::SourceMgr::DK_Error,
"Unknown instrumentation type in LLVM-MCA comment: " +
InstrumentKind);
FoundError = true;
return;
}
UniqueInstrument I = IM.createInstrument(InstrumentKind, Data);
if (!I) {
if (Data.empty())
SM.PrintMessage(Loc, llvm::SourceMgr::DK_Error,
"Failed to create " + InstrumentKind +
" instrument with no data");
else
SM.PrintMessage(Loc, llvm::SourceMgr::DK_Error,
"Failed to create " + InstrumentKind +
" instrument with data: " + Data);
FoundError = true;
return;
}
// End InstrumentType region if one is open
if (Regions.isRegionActive(InstrumentKind))
Regions.endRegion(InstrumentKind, Loc);
// Start new instrumentation region
Regions.beginRegion(InstrumentKind, Loc, std::move(I));
}
} // namespace mca
} // namespace llvm
|
