Summary:
Instruments is a useful tool for finding performance issues in LLVM but it can
be difficult to identify regions of interest on the timeline that we can use
to filter the profiler or allocations instrument. Xcode 10 and the latest
macOS/iOS/etc. added support for the os_signpost() API which allows us to
annotate the timeline with information that's meaningful to LLVM.
This patch causes timer start and end events to emit signposts. When used with
-time-passes, this causes the passes to be annotated on the Instruments timeline.
In addition to visually showing the duration of passes on the timeline, it also
allows us to filter the profile and allocations instrument down to an individual
pass allowing us to find the issues within that pass without being drowned out
by the noise from other parts of the compiler.
Using this in conjunction with the Time Profiler (in high frequency mode) and
the Allocations instrument is how I found the SparseBitVector that should have
been a BitVector and the DenseMap that could be replaced by a sorted vector a
couple months ago. I added NamedRegionTimers to TableGen and used the resulting
annotations to identify the slow portions of the Register Info Emitter. Some of
these were placed according to educated guesses while others were placed
according to hot functions from a previous profile. From there I filtered the
profile to a slow portion and the aforementioned issues stood out in the
profile.
To use this feature enable LLVM_SUPPORT_XCODE_SIGNPOSTS in CMake and run the
compiler under Instruments with -time-passes like so:
instruments -t 'Time Profiler' bin/llc -time-passes -o - input.ll'
Then open the resulting trace in Instruments.
There was a talk at WWDC 2018 that explained the feature which can be found at
https://developer.apple.com/videos/play/wwdc2018/405/ if you'd like to know
more about it.
Reviewers: bogner
Reviewed By: bogner
Subscribers: jdoerfert, mgorny, kristina, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D52954
llvm-svn: 354365
The LLVM Support library implementation has resided in
//llvm/lib/Support for a significant amount of time now,
with documentation having been updated with all references
to the "System library" being replaced with "Support library".
Since this file mirrors already existing documentation available
for Support library, includes dead links to documentation and
still refers to it as "System library", having it there is
confusing and updating it has very little point as it duplicates
information in documentation, except documentation is a lot more
up to date while this file has not been maintained.
Up to date documentation concerning this can be found here:
http://llvm.org/docs/SupportLibrary.html
llvm-svn: 354209
This reverts commit r351091.
The original mac breakages are addressed by ensuring the root directory
we're working from is fully symlink-resolved before starting.
Differential Revision: https://reviews.llvm.org/D58169
llvm-svn: 354026
Moved the remove of the temporary file to after the close to avoid
remove failures caused by ETXTBSY errors.
This issue was seen when FileOutputBuffer falls back to an in memory
buffer due to the inability to mmap the on disk file. This occurred when
running LLD on an Ubuntu VM in VirtualBox on a Windows host attempting
to write the output to a VirtualBox shared folder.
Differential Revision: https://reviews.llvm.org/D57960
llvm-svn: 354017
We implicitly mark this feature as enabled when the target is 64-bits, but our detection code for -march=native didn't support it so you can't detect it on 32-bit targets.
llvm-svn: 353963
JMP32 instructions has been added to eBPF ISA. They are 32-bit variants of
existing BPF conditional jump instructions, but the comparison happens on
low 32-bit sub-register only, therefore some unnecessary extensions could
be saved.
JMP32 instructions will only be available for -mcpu=v3. Host probe hook has
been updated accordingly.
JMP32 instructions will only be enabled in code-gen when -mattr=+alu32
enabled, meaning compiling the program using sub-register mode.
For JMP32 encoding, it is a new instruction class, and is using the
reserved eBPF class number 0x6.
This patch has been tested by compiling and running kernel bpf selftests
with JMP32 enabled.
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
llvm-svn: 353384
As far as I can tell, malloc.h is only being used here to provide
a definition of mallinfo (malloc itself is declared in stdlib.h via
cstdlib). We already have a macro for whether mallinfo is available,
so switch to using that instead.
Differential Revision: https://reviews.llvm.org/D57807
llvm-svn: 353329
Summary:
Add support for options that always prefix their value, giving an error
if the value is in the next argument or if the option is given a value
assignment (ie. opt=val). This is the desired behavior for the -D option
of FileCheck for instance.
Copyright:
- Linaro (changes in version 2 of revision D55940)
- GraphCore (changes in later versions and introduced when creating
D56549)
Reviewers: jdenny
Subscribers: llvm-commits, probinson, kristina, hiraditya,
JonChesterfield
Differential Revision: https://reviews.llvm.org/D56549
llvm-svn: 353172
In order to make an option value truly optional, both the ValueOptional
attribute and an empty-named value are required. Prior to this change,
this empty-named value appears in the command-line help text:
-some-option - some help text
=v1 - description 1
=v2 - description 2
= -
This change improves the help text for these sort of options in a number
of ways:
1) ValueOptional options with an empty-named value now print their help
text twice: both without and then with '=<value>' after the name. The
latter version then lists the allowed values after it.
2) Empty-named values with no help text in ValueOptional options are not
listed in the permitted values.
-some-option - some help text
-some-option=<value> - some help text
=v1 - description 1
=v2 - description 2
3) Otherwise empty-named options are printed as =<empty> rather than
simply '='.
4) Option values without help text do not have the '-' separator
printed.
-some-option=<value> - some help text
=v1 - description 1
=v2
=<empty> - description
It also tweaks the llvm-symbolizer -functions help text to not print a
trailing ':' as that looks bad combined with 1) above.
This is mostly a reland of r353048 which in turn was a reland of
r352750.
Reviewed by: ruiu, thopre, mstorsjo
Differential Revision: https://reviews.llvm.org/D57030
llvm-svn: 353053
In order to make an option value truly optional, both the ValueOptional
attribute and an empty-named value are required. Prior to this change,
this empty-named value appears in the command-line help text:
-some-option - some help text
=v1 - description 1
=v2 - description 2
= -
This change improves the help text for these sort of options in a number
of ways:
1) ValueOptional options with an empty-named value now print their help
text twice: both without and then with '=<value>' after the name. The
latter version then lists the allowed values after it.
2) Empty-named values with no help text in ValueOptional options are not
listed in the permitted values.
-some-option - some help text
-some-option=<value> - some help text
=v1 - description 1
=v2 - description 2
3) Otherwise empty-named options are printed as =<empty> rather than
simply '='.
4) Option values without help text do not have the '-' separator
printed.
-some-option=<value> - some help text
=v1 - description 1
=v2
=<empty> - description
It also tweaks the llvm-symbolizer -functions help text to not print a
trailing ':' as that looks bad combined with 1) above.
This is mostly a reland of r352750.
Reviewed by: ruiu, thopre, mstorsjo
Differential Revision: https://reviews.llvm.org/D57030
llvm-svn: 353048
In order to make an option value truly optional, both the ValueOptional
and an empty-named value are required. This empty-named value appears in
the command-line help text, which is not ideal.
This change improves the help text for these sort of options in a number
of ways:
1) ValueOptional options with an empty-named value now print their help
text twice: both without and then with '=<value>' after the name. The
latter version then lists the allowed values after it.
2) Empty-named values with no help text in ValueOptional options are not
listed in the permitted values.
3) Otherwise empty-named options are printed as =<empty> rather than
simply '='.
4) Option values without help text do not have the '-' separator
printed.
It also tweaks the llvm-symbolizer -functions help text to not print a
trailing ':' as that looks bad combined with 1) above.
Reviewed by: thopre, ruiu
Differential Revision: https://reviews.llvm.org/D57030
llvm-svn: 352750
Previously, MemoryBlock automatically extends a requested buffer size to a
multiple of page size because (I believe) doing it was thought to be harmless
and with that you could get more memory (on average 2KiB on 4KiB-page systems)
"for free".
That programming interface turned out to be error-prone. If you request N
bytes, you usually expect that a resulting object returns N for `size()`.
That's not the case for MemoryBlock.
Looks like there is only one place where we take the advantage of
allocating more memory than the requested size. So, with this patch, I
simply removed the automatic size expansion feature from MemoryBlock
and do it on the caller side when needed. MemoryBlock now always
returns a buffer whose size is equal to the requested size.
Differential Revision: https://reviews.llvm.org/D56941
llvm-svn: 351916
If the underlying filesystem does not support mmap system call,
FileOutputBuffer may fail when it attempts to mmap an output temporary
file. This patch handles such situation.
Unfortunately, it looks like it is very hard to test this functionality
without a filesystem that doesn't support mmap using llvm-lit. I tested
this locally by passing an invalid parameter to mmap so that it fails and
falls back to the in-memory buffer. Maybe that's all what we can do.
I believe it is reasonable to submit this without a test.
Differential Revision: https://reviews.llvm.org/D56949
llvm-svn: 351883
The old diagnostic form of the trace produced by -v and -vv looks
like:
```
check1:1:8: remark: CHECK: expected string found in input
CHECK: abc
^
<stdin>:1:3: note: found here
; abc def
^~~
```
When dumping annotated input is requested (via -dump-input), I find
that this old trace is not useful and is sometimes harmful:
1. The old trace is mostly redundant because the same basic
information also appears in the input dump's annotations.
2. The old trace buries any error diagnostic between it and the input
dump, but I find it useful to see any error diagnostic up front.
3. FILECHECK_OPTS=-dump-input=fail requests annotated input dumps only
for failed FileCheck calls. However, I have to also add -v or -vv
to get a full set of annotations, and that can produce massive
output from all FileCheck calls in all tests. That's a real
problem when I run this in the IDE I use, which grinds to a halt as
it tries to capture all that output.
When -dump-input=fail|always, this patch suppresses the old trace from
-v or -vv. Error diagnostics still print as usual. If you want the
old trace, perhaps to see variable expansions, you can set
-dump-input=none (the default).
Reviewed By: probinson
Differential Revision: https://reviews.llvm.org/D55825
llvm-svn: 351881
I was honestly a bit surprised that we didn't do this before. This
patch is to handle "-" as the stdout so that if you pass `-o -` to
lld, for example, it writes an output to stdout instead of file `-`.
I thought that we might want to handle this at a higher level than
FileOutputBuffer, because if we land this patch, we can no longer
create a file whose name is `-` (there's a workaround though; you can
pass `./-` instead of `-`). However, because raw_fd_ostream already
handles `-` as a special file name, I think it's okay and actually
consistent to handle `-` as a special name in FileOutputBuffer.
Differential Revision: https://reviews.llvm.org/D56940
llvm-svn: 351852
to reflect the new license. These used slightly different spellings that
defeated my regular expressions.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351648
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
Summary:
The operators simply print the underlying value or "None".
The trickier part of this patch is making sure the streaming operators
work even in unit tests (which was my primary motivation, though I can
also see them being useful elsewhere). Since the stream operator was a
template, implicit conversions did not kick in, and our gtest glue code
was explicitly introducing an implicit conversion to make sure other
implicit conversions do not kick in :P. I resolve that by specializing
llvm_gtest::StreamSwitch for llvm:Optional<T>.
Reviewers: sammccall, dblaikie
Reviewed By: sammccall
Subscribers: mgorny, dexonsmith, kristina, llvm-commits
Differential Revision: https://reviews.llvm.org/D56795
llvm-svn: 351548
With this patch, the copies of the files ItaniumDemangle.h,
StringView.h, and Utility.h are kept byte-for-byte in sync between
libcxxabi and llvm. All differences (namespaces, fallthrough, and
unreachable macros) are defined in each copies' DemanglerConfig.h.
This patch also adds a script to copy changes from libcxxabi
(cp-to-llvm.sh), and a README.txt explaining the situation.
Differential revision: https://reviews.llvm.org/D53538
llvm-svn: 351474
Summary:
The version of make_absolute which accepted a specific directory to use
as the "base" for the computation could never fail, even though it
returned a std::error_code. The reason for that seems to be historical
-- the CWD flavour (which can fail due to failure to retrieve CWD) was
there first, and the new version was implemented by extending that.
This removes the error return value from the non-CWD overload and
reimplements the CWD version on top of that. This enables us to remove
some dead code where people were pessimistically trying to handle the
errors returned from this function.
Reviewers: zturner, sammccall
Subscribers: hiraditya, kristina, llvm-commits
Differential Revision: https://reviews.llvm.org/D56599
llvm-svn: 351317
This adds support for multilib paths for wasm32 targets, following
[Debian's Multiarch conventions], and also adds an experimental OS name in
order to test it.
[Debian's Multiarch conventions]: https://wiki.debian.org/Multiarch/
Differential Revision: https://reviews.llvm.org/D56553
llvm-svn: 351163
Summary:
Previously only one RealFileSystem instance was available, and its working
directory is shared with the process. This doesn't work well for multithreaded
programs that want to work with relative paths - the vfs::FileSystem is assumed
to provide the working directory, but a thread cannot control this exclusively.
The new vfs::createPhysicalFileSystem() factory copies the process's working
directory initially, and then allows it to be independently modified.
This implementation records the working directory path, and glues it to relative
paths to provide the correct absolute path to the sys::fs:: functions.
This will give different results in unusual situations (e.g. the CWD is moved).
The main alternative is the use of openat(), fstatat(), etc to ask the OS to
resolve paths relative to a directory handle which can be kept open. This is
more robust. There are two reasons not to do this initially:
1. these functions are not available on all supported Unixes, and are somewhere
between difficult and unavailable on Windows. So we need a path-based
fallback anyway.
2. this would mean also adding support at the llvm::sys::fs level, which is a
larger project. My clearest idea is an OS-specific `BaseDirectory` object
that can be optionally passed to functions there. Eventually this could be
backed by either paths or a fd where openat() is supported.
This is a large project, and demonstrating here that a path-based fallback
works is a useful prerequisite.
There is some subtlety to the path-manipulation mechanism:
- when setting the working directory, both Specified=makeAbsolute(path) and
Resolved=realpath(path) are recorded. These may differ in the presence of
symlinks.
- getCurrentWorkingDirectory() and makeAbsolute() use Specified - this is
similar to the behavior of $PWD and sys::path::current_path
- IO operations like openFileForRead use Resolved. This is similar to the
behavior of an openat() based implementation, that doesn't see changes
in symlinks.
There may still be combinations of operations and FS states that yield unhelpful
behavior. This is hard to avoid with symlinks and FS abstractions :(
The caching behavior of the current working directory is removed in this patch.
getRealFileSystem() is now specified to link to the process CWD, so the caching
is incorrect.
The user who needed this so far is clangd, which will immediately switch to
createPhysicalFileSystem().
Reviewers: ilya-biryukov, bkramer, labath
Subscribers: ioeric, kadircet, kristina, llvm-commits
Differential Revision: https://reviews.llvm.org/D56545
llvm-svn: 351050
Summary:
Add support for options that always prefix their value, giving an error
if the value is in the next argument or if the option is given a value
assignment (ie. opt=val). This is the desired behavior for the -D option
of FileCheck for instance.
Copyright:
- Linaro (changes in version 2 of revision D55940)
- GraphCore (changes in later versions and introduced when creating
D56549)
Reviewers: jdenny
Subscribers: llvm-commits, probinson, kristina, hiraditya,
JonChesterfield
Differential Revision: https://reviews.llvm.org/D56549
llvm-svn: 351038
Apply final suggestions from probinson for this patch series plus a
few more tweaks:
* Improve various docs, for MatchType in particular.
* Rename some members of MatchType. The main problem was that the
term "final match" became a misnomer when CHECK-COUNT-<N> was
created.
* Split InputStartLine, etc. declarations into multiple lines.
Differential Revision: https://reviews.llvm.org/D55738
Reviewed By: probinson
llvm-svn: 349425
This patch implements annotations for diagnostics reporting CHECK-NOT
failed matches. These diagnostics are enabled by -vv. As for
diagnostics reporting failed matches for other directives, these
annotations mark the search ranges using `X~~`. The difference here
is that failed matches for CHECK-NOT are successes not errors, so they
are green not red when colors are enabled.
For example:
```
$ FileCheck -dump-input=help
The following description was requested by -dump-input=help to
explain the input annotations printed by -dump-input=always and
-dump-input=fail:
- L: labels line number L of the input file
- T:L labels the only match result for a pattern of type T from line L of
the check file
- T:L'N labels the Nth match result for a pattern of type T from line L of
the check file
- ^~~ marks good match (reported if -v)
- !~~ marks bad match, such as:
- CHECK-NEXT on same line as previous match (error)
- CHECK-NOT found (error)
- CHECK-DAG overlapping match (discarded, reported if -vv)
- X~~ marks search range when no match is found, such as:
- CHECK-NEXT not found (error)
- CHECK-NOT not found (success, reported if -vv)
- CHECK-DAG not found after discarded matches (error)
- ? marks fuzzy match when no match is found
- colors success, error, fuzzy match, discarded match, unmatched input
If you are not seeing color above or in input dumps, try: -color
$ FileCheck -vv -dump-input=always check5 < input5 |& sed -n '/^<<<</,$p'
<<<<<<
1: abcdef
check:1 ^~~
not:2 X~~
2: ghijkl
not:2 ~~~
check:3 ^~~
3: mnopqr
not:4 X~~~~~
4: stuvwx
not:4 ~~~~~~
5:
eof:4 ^
>>>>>>
$ cat check5
CHECK: abc
CHECK-NOT: foobar
CHECK: jkl
CHECK-NOT: foobar
$ cat input5
abcdef
ghijkl
mnopqr
stuvwx
```
Reviewed By: george.karpenkov, probinson
Differential Revision: https://reviews.llvm.org/D53899
llvm-svn: 349424
This patch implements input annotations for diagnostics reporting
CHECK-DAG discarded matches. These diagnostics are enabled by -vv.
These annotations mark discarded match ranges using `!~~` because they
are bad matches even though they are not errors.
CHECK-DAG discarded matches create another case where there can be
multiple match results for the same directive.
For example:
```
$ FileCheck -dump-input=help
The following description was requested by -dump-input=help to
explain the input annotations printed by -dump-input=always and
-dump-input=fail:
- L: labels line number L of the input file
- T:L labels the only match result for a pattern of type T from line L of
the check file
- T:L'N labels the Nth match result for a pattern of type T from line L of
the check file
- ^~~ marks good match (reported if -v)
- !~~ marks bad match, such as:
- CHECK-NEXT on same line as previous match (error)
- CHECK-NOT found (error)
- CHECK-DAG overlapping match (discarded, reported if -vv)
- X~~ marks search range when no match is found, such as:
- CHECK-NEXT not found (error)
- CHECK-DAG not found after discarded matches (error)
- ? marks fuzzy match when no match is found
- colors success, error, fuzzy match, discarded match, unmatched input
If you are not seeing color above or in input dumps, try: -color
$ FileCheck -vv -dump-input=always check4 < input4 |& sed -n '/^<<<</,$p'
<<<<<<
1: abcdef
dag:1 ^~~~
dag:2'0 !~~~ discard: overlaps earlier match
2: cdefgh
dag:2'1 ^~~~
check:3 X~ error: no match found
>>>>>>
$ cat check4
CHECK-DAG: abcd
CHECK-DAG: cdef
CHECK: efgh
$ cat input4
abcdef
cdefgh
```
This shows that the line 3 CHECK fails to match even though its
pattern appears in the input because its search range starts after the
line 2 CHECK-DAG's match range. The trouble might be that the line 2
CHECK-DAG's match range is later than expected because its first match
range overlaps with the line 1 CHECK-DAG match range and thus is
discarded.
Because `!~~` for CHECK-DAG does not indicate an error, it is not
colored red. Instead, when colors are enabled, it is colored cyan,
which suggests a match that went cold.
Reviewed By: george.karpenkov, probinson
Differential Revision: https://reviews.llvm.org/D53898
llvm-svn: 349423
This patch implements input annotations for diagnostics enabled by -v,
which report good matches for directives. These annotations mark
match ranges using `^~~`.
For example:
```
$ FileCheck -dump-input=help
The following description was requested by -dump-input=help to
explain the input annotations printed by -dump-input=always and
-dump-input=fail:
- L: labels line number L of the input file
- T:L labels the only match result for a pattern of type T from line L of
the check file
- T:L'N labels the Nth match result for a pattern of type T from line L of
the check file
- ^~~ marks good match (reported if -v)
- !~~ marks bad match, such as:
- CHECK-NEXT on same line as previous match (error)
- CHECK-NOT found (error)
- X~~ marks search range when no match is found, such as:
- CHECK-NEXT not found (error)
- ? marks fuzzy match when no match is found
- colors success, error, fuzzy match, unmatched input
If you are not seeing color above or in input dumps, try: -color
$ FileCheck -v -dump-input=always check3 < input3 |& sed -n '/^<<<</,$p'
<<<<<<
1: abc foobar def
check:1 ^~~
not:2 !~~~~~ error: no match expected
check:3 ^~~
>>>>>>
$ cat check3
CHECK: abc
CHECK-NOT: foobar
CHECK: def
$ cat input3
abc foobar def
```
-vv enables these annotations for FileCheck's implicit EOF patterns as
well. For an example where EOF patterns become relevant, see patch 7
in this series.
If colors are enabled, `^~~` is green to suggest success.
-v plus color enables highlighting of input text that has no final
match for any expected pattern. The highlight uses a cyan background
to suggest a cold section. This highlighting can make it easier to
spot text that was intended to be matched but that failed to be
matched in a long series of good matches.
CHECK-COUNT-<num> good matches are another case where there can be
multiple match results for the same directive.
Reviewed By: george.karpenkov, probinson
Differential Revision: https://reviews.llvm.org/D53897
llvm-svn: 349422
This patch implements input annotations for diagnostics that report
unexpected matches for CHECK-NOT. Like wrong-line matches for
CHECK-NEXT, CHECK-SAME, and CHECK-EMPTY, these annotations mark match
ranges using red `!~~` to indicate bad matches that are errors.
For example:
```
$ FileCheck -dump-input=help
The following description was requested by -dump-input=help to
explain the input annotations printed by -dump-input=always and
-dump-input=fail:
- L: labels line number L of the input file
- T:L labels the only match result for a pattern of type T from line L of
the check file
- T:L'N labels the Nth match result for a pattern of type T from line L of
the check file
- !~~ marks bad match, such as:
- CHECK-NEXT on same line as previous match (error)
- CHECK-NOT found (error)
- X~~ marks search range when no match is found, such as:
- CHECK-NEXT not found (error)
- ? marks fuzzy match when no match is found
- colors error, fuzzy match
If you are not seeing color above or in input dumps, try: -color
$ FileCheck -v -dump-input=always check3 < input3 |& sed -n '/^<<<</,$p'
<<<<<<
1: abc foobar def
not:2 !~~~~~ error: no match expected
>>>>>>
$ cat check3
CHECK: abc
CHECK-NOT: foobar
CHECK: def
$ cat input3
abc foobar def
```
Reviewed By: george.karpenkov, probinson
Differential Revision: https://reviews.llvm.org/D53896
llvm-svn: 349421
This patch implements input annotations for diagnostics that report
wrong-line matches for the directives CHECK-NEXT, CHECK-SAME, and
CHECK-EMPTY. Instead of the usual `^~~`, which is used by later
patches for good matches, these annotations use `!~~` to mark the bad
match ranges so that this category of errors is visually distinct.
Because such matches are errors, these annotates are red when colors
are enabled.
For example:
```
$ FileCheck -dump-input=help
The following description was requested by -dump-input=help to
explain the input annotations printed by -dump-input=always and
-dump-input=fail:
- L: labels line number L of the input file
- T:L labels the only match result for a pattern of type T from line L of
the check file
- T:L'N labels the Nth match result for a pattern of type T from line L of
the check file
- !~~ marks bad match, such as:
- CHECK-NEXT on same line as previous match (error)
- X~~ marks search range when no match is found, such as:
- CHECK-NEXT not found (error)
- ? marks fuzzy match when no match is found
- colors error, fuzzy match
If you are not seeing color above or in input dumps, try: -color
$ FileCheck -v -dump-input=always check2 < input2 |& sed -n '/^<<<</,$p'
<<<<<<
1: foo bar
next:2 !~~ error: match on wrong line
>>>>>>
$ cat check2
CHECK: foo
CHECK-NEXT: bar
$ cat input2
foo bar
```
Reviewed By: george.karpenkov, probinson
Differential Revision: https://reviews.llvm.org/D53894
llvm-svn: 349420
