333 Commits

Author SHA1 Message Date
Nico Weber
b995314143 Revert "[InstrProfiling] Use !associated metadata for counters, data and values"
This reverts commit 97ba5cde52664200819446c1a18de28faf2ed1c6.
Still breaks tests: https://reviews.llvm.org/D76802#2540647
2021-02-03 19:14:34 -05:00
Petr Hosek
97ba5cde52 [InstrProfiling] Use !associated metadata for counters, data and values
C identifier name input sections such as __llvm_prf_* are GC roots so
they cannot be discarded. In LLD, the SHF_LINK_ORDER flag overrides the
C identifier name semantics.

The !associated metadata may be attached to a global object declaration
with a single argument that references another global object, and it
gets lowered to SHF_LINK_ORDER flag. When a function symbol is discarded
by the linker, setting up !associated metadata allows linker to discard
counters, data and values associated with that function symbol.

Note that !associated metadata is only supported by ELF, it does not have
any effect on non-ELF targets.

Differential Revision: https://reviews.llvm.org/D76802
2021-02-02 23:19:51 -08:00
Tom Weaver
4f1320b77d Revert "[InstrProfiling] Use !associated metadata for counters, data and values"
This reverts commit df3e39f60b356ca9dbfc11e96e5fdda30afa7acb.

introduced failing test instrprof-gc-sections.c
causing build bot to fail:
http://lab.llvm.org:8011/#/builders/53/builds/1184
2021-02-02 14:19:31 +00:00
Fangrui Song
327196d688 [test] Fix unused FileCheck prefixes in compiler-rt/test 2021-02-01 21:24:58 -08:00
Petr Hosek
df3e39f60b [InstrProfiling] Use !associated metadata for counters, data and values
C identifier name input sections such as __llvm_prf_* are GC roots so
they cannot be discarded. In LLD, the SHF_LINK_ORDER flag overrides the
C identifier name semantics.

The !associated metadata may be attached to a global object declaration
with a single argument that references another global object, and it
gets lowered to SHF_LINK_ORDER flag. When a function symbol is discarded
by the linker, setting up !associated metadata allows linker to discard
counters, data and values associated with that function symbol.

Note that !associated metadata is only supported by ELF, it does not have
any effect on non-ELF targets.

Differential Revision: https://reviews.llvm.org/D76802
2021-02-01 15:01:43 -08:00
Fangrui Song
f23fae29eb [test] Fix compiler-rt/test/profile/coverage_emptylines.cpp if the build directory is under /tmp
llvm-cov -path-equivalence=/tmp,... is used by some checked-in coverage mapping
files where the original filename is under /tmp. If the test itself produces the
coverage mapping file, there is no need for /tmp.

For coverage_emptylines.cpp: the source filename is under the build directory.
If the build directory is under /tmp, the path mapping will make
llvm-cov fail to find the file.
2020-12-10 16:57:10 -08:00
Xinhao Yuan
97260ab478 [llvm-cov][gcov] Optimize the cycle counting algorithm by skipping zero count cycles
This change is similar to http://gcc.gnu.org/PR90380

This reduces the complexity from exponential to polynomial of the arcs.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D93036
2020-12-10 15:22:29 -08:00
Arthur Eubanks
5c31b8b94f Revert "Use uint64_t for branch weights instead of uint32_t"
This reverts commit 10f2a0d662d8d72eaac48d3e9b31ca8dc90df5a4.

More uint64_t overflows.
2020-10-31 00:25:32 -07:00
Arthur Eubanks
10f2a0d662 Use uint64_t for branch weights instead of uint32_t
CallInst::updateProfWeight() creates branch_weights with i64 instead of i32.
To be more consistent everywhere and remove lots of casts from uint64_t
to uint32_t, use i64 for branch_weights.

Reviewed By: davidxl

Differential Revision: https://reviews.llvm.org/D88609
2020-10-30 10:03:46 -07:00
Nico Weber
2a4e704c92 Revert "Use uint64_t for branch weights instead of uint32_t"
This reverts commit e5766f25c62c185632e3a75bf45b313eadab774b.
Makes clang assert when building Chromium, see https://crbug.com/1142813
for a repro.
2020-10-27 09:26:21 -04:00
Arthur Eubanks
e5766f25c6 Use uint64_t for branch weights instead of uint32_t
CallInst::updateProfWeight() creates branch_weights with i64 instead of i32.
To be more consistent everywhere and remove lots of casts from uint64_t
to uint32_t, use i64 for branch_weights.

Reviewed By: davidxl

Differential Revision: https://reviews.llvm.org/D88609
2020-10-26 20:24:04 -07:00
Vedant Kumar
a77a739abc [profile] Suppress spurious 'expected profile to require unlock' warning
In %c (continuous sync) mode, avoid attempting to unlock an
already-unlocked profile.

The profile is only locked when profile merging is enabled.
2020-10-26 16:25:08 -07:00
Vedant Kumar
62c372770d [profile] Add %t LLVM_PROFILE_FILE option to substitute $TMPDIR
Add support for expanding the %t filename specifier in LLVM_PROFILE_FILE
to the TMPDIR environment variable. This is supported on all platforms.

On Darwin, TMPDIR is used to specify a temporary application-specific
scratch directory. When testing apps on remote devices, it can be
challenging for the host device to determine the correct TMPDIR, so it's
helpful to have the runtime do this work.

rdar://68524185

Differential Revision: https://reviews.llvm.org/D87332
2020-09-25 09:39:40 -07:00
Zequan Wu
9caa3fbe03 [Coverage] Add empty line regions to SkippedRegions
Differential Revision: https://reviews.llvm.org/D84988
2020-09-21 12:42:53 -07:00
Fangrui Song
63182c2ac0 [gcov] Add spanning tree optimization
gcov is an "Edge Profiling with Edge Counters" application according to
Optimally Profiling and Tracing Programs (1994).

The minimum number of counters necessary is |E|-(|V|-1). The unmeasured edges
form a spanning tree. Both GCC --coverage and clang -fprofile-generate leverage
this optimization. This patch implements the optimization for clang --coverage.
The produced .gcda files are much smaller now.
2020-09-13 00:07:31 -07:00
Fangrui Song
8cf1ac97ce [llvm-cov gcov] Improve accuracy when some edges are not measured
Also guard against infinite recursion if GCOV_ARC_ON_TREE edges contain a cycle.
2020-09-12 22:33:41 -07:00
Rainer Orth
76e85ae268 [clang][Sparc] Default to -mcpu=v9 for Sparc V8 on Solaris
As reported in Bug 42535, `clang` doesn't inline atomic ops on 32-bit
Sparc, unlike `gcc` on Solaris.  In a 1-stage build with `gcc`, only two
testcases are affected (currently `XFAIL`ed), while in a 2-stage build more
than 100 tests `FAIL` due to this issue.

The reason for this `gcc`/`clang` difference is that `gcc` on 32-bit
Solaris/SPARC defaults to `-mpcu=v9` where atomic ops are supported, unlike
with `clang`'s default of `-mcpu=v8`.  This patch changes `clang` to use
`-mcpu=v9` on 32-bit Solaris/SPARC, too.

Doing so uncovered two bugs:

`clang -m32 -mcpu=v9` chokes with any Solaris system headers included:

  /usr/include/sys/isa_defs.h:461:2: error: "Both _ILP32 and _LP64 are defined"
  #error "Both _ILP32 and _LP64 are defined"

While `clang` currently defines `__sparcv9` in a 32-bit `-mcpu=v9`
compilation, neither `gcc` nor Studio `cc` do.  In fact, the Studio 12.6
`cc(1)` man page clearly states:

            These predefinitions are valid in all modes:
  [...]
               __sparcv8 (SPARC)
               __sparcv9 (SPARC -m64)

At the same time, the patch defines `__GCC_HAVE_SYNC_COMPARE_AND_SWAP_[1248]`
for a 32-bit Sparc compilation with any V9 cpu.  I've also changed
`MaxAtomicInlineWidth` for V9, matching what `gcc` does and the Oracle
Developer Studio 12.6: C User's Guide documents (Ch. 3, Support for Atomic
Types, 3.1 Size and Alignment of Atomic C Types).

The two testcases that had been `XFAIL`ed for Bug 42535 are un-`XFAIL`ed
again.

Tested on `sparcv9-sun-solaris2.11` and `amd64-pc-solaris2.11`.

Differential Revision: https://reviews.llvm.org/D86621
2020-09-11 09:53:19 +02:00
Fangrui Song
b9d086693b [llvm-cov gcov] Compute unmeasured arc counts by Kirchhoff's circuit law
For a CFG G=(V,E), Knuth describes that by Kirchoff's circuit law, the minimum
number of counters necessary is |E|-(|V|-1). The emitted edges form a spanning
tree. libgcov emitted .gcda files leverages this optimization while clang
--coverage's doesn't.

Propagate counts by Kirchhoff's circuit law so that llvm-cov gcov can
correctly print line counts of gcc --coverage emitted files and enable
the future improvement of clang --coverage.
2020-09-08 18:45:11 -07:00
Rainer Orth
13080ca1f0 [compiler-rt][test] XFAIL two tests on 32-bit sparc
Two tests `FAIL` on 32-bit sparc:

  Profile-sparc :: Posix/instrprof-gcov-parallel.test
  UBSan-Standalone-sparc :: TestCases/Float/cast-overflow.cpp

The failure mode is similar:

  Undefined                       first referenced
   symbol                             in file
  __atomic_store_4                    /var/tmp/instrprof-gcov-parallel-6afe8d.o
  __atomic_load_4                     /var/tmp/instrprof-gcov-parallel-6afe8d.o

  Undefined                       first referenced
   symbol                             in file
  __atomic_load_1                     /var/tmp/cast-overflow-72a808.o

This is a known bug: `clang` doesn't inline atomics on 32-bit sparc, unlike
`gcc`.

The patch therefore `XFAIL`s the tests.

Tested on `sparcv9-sun-solaris2.11` and `amd64-pc-solaris2.11`.

Differential Revision: https://reviews.llvm.org/D85346
2020-08-18 11:32:51 +02:00
Dávid Bolvanský
0f14b2e6cb Revert "[BPI] Improve static heuristics for integer comparisons"
This reverts commit 50c743fa713002fe4e0c76d23043e6c1f9e9fe6f. Patch will be split to smaller ones.
2020-08-17 20:44:33 +02:00
Dávid Bolvanský
3944d3df4f [Tests] Removed debug copy command 2020-08-13 20:21:19 +02:00
Dávid Bolvanský
50c743fa71 [BPI] Improve static heuristics for integer comparisons
Similarly as for pointers, even for integers a == b is usually false.

GCC also uses this heuristic.

Reviewed By: ebrevnov

Differential Revision: https://reviews.llvm.org/D85781
2020-08-13 19:54:27 +02:00
Vedant Kumar
896f797b8b [profile] Remove dependence on getpagesize from InstrProfilingBuffer.c.o
InstrProfilingBuffer.c.o is generic code that must support compilation
into freestanding projects. This gets rid of its dependence on the
_getpagesize symbol from libc, shifting it to InstrProfilingFile.c.o.

This fixes a build failure seen in a firmware project.

rdar://66249701
2020-07-30 16:22:40 -07:00
Hiroshi Yamauchi
3d6f53018f [PGO] Include the mem ops into the function hash.
To avoid hash collisions when the only difference is in mem ops.
2020-07-30 09:26:20 -07:00
Hiroshi Yamauchi
ae7589e1f1 Revert "[PGO] Include the mem ops into the function hash."
This reverts commit 120e66b3418b37b95fc1dbbb23e296a602a24fa8.

Due to a buildbot failure.
2020-07-29 15:04:57 -07:00
Hiroshi Yamauchi
120e66b341 [PGO] Include the mem ops into the function hash.
To avoid hash collisions when the only difference is in mem ops.

Differential Revision: https://reviews.llvm.org/D84782
2020-07-29 13:59:40 -07:00
Zequan Wu
b46176bbb0 Reland [Coverage] Add comment to skipped regions
Bug filled here: https://bugs.llvm.org/show_bug.cgi?id=45757.
Add comment to skipped regions so we don't track execution count for lines containing only comments.

Differential Revision: https://reviews.llvm.org/D83592
2020-07-28 13:20:57 -07:00
Fangrui Song
746b5fad5b [profile][test] Add -fuse-ld=bfd to make instrprof-lto-pgogen.c robust
Otherwise if 'ld' is an older system LLD (FreeBSD; or if someone adds 'ld' to
point to an LLD from a different installation) which does not support the
current ModuleSummaryIndex::BitCodeSummaryVersion, the test will fail.

Add lit feature 'binutils_lto'. GNU ld is more common than GNU gold, so
we can just require 'is_binutils_lto_supported' to additionally support GNU ld.

Reviewed By: myhsu

Differential Revision: https://reviews.llvm.org/D84133
2020-07-22 10:16:08 -07:00
Hans Wennborg
238bbd48c5 Revert abd45154b "[Coverage] Add comment to skipped regions"
This casued assertions during Chromium builds. See comment on the code review

> Bug filled here: https://bugs.llvm.org/show_bug.cgi?id=45757.
> Add comment to skipped regions so we don't track execution count for lines containing only comments.
>
> Differential Revision: https://reviews.llvm.org/D84208

This reverts commit abd45154bdb6b76c5b480455eacc8c75b08242aa and the
follow-up 87d725473380652bbe845fd2fbd9c0507a55172f.
2020-07-22 17:09:20 +02:00
Zequan Wu
87d7254733 [Coverage] Fix coverage test cases. 2020-07-21 18:01:29 -07:00
Zequan Wu
abd45154bd [Coverage] Add comment to skipped regions
Bug filled here: https://bugs.llvm.org/show_bug.cgi?id=45757.
Add comment to skipped regions so we don't track execution count for lines containing only comments.

Differential Revision: https://reviews.llvm.org/D84208
2020-07-21 17:34:18 -07:00
Jon Roelofs
b9fc20ebe7 [compiler-rt][test][profile] Fix missing include
... on systems where wait() isn't one of the declarations transitively included
via unistd.h (i.e. Darwin).

Differential Revision: https://reviews.llvm.org/D84207
2020-07-21 11:59:27 -06:00
Fangrui Song
5809a32e7c [gcov] Add __gcov_dump/__gcov_reset and delete __gcov_flush
GCC r187297 (2012-05) introduced `__gcov_dump` and `__gcov_reset`.
  `__gcov_flush = __gcov_dump + __gcov_reset`

The resolution to https://gcc.gnu.org/PR93623 ("No need to dump gcdas when forking" target GCC 11.0) removed the unuseful and undocumented __gcov_flush.

Close PR38064.

Reviewed By: calixte, serge-sans-paille

Differential Revision: https://reviews.llvm.org/D83149
2020-07-18 15:07:46 -07:00
Fangrui Song
6a25838be6 [gcov][test] Simplify instrprof-dlopen-dlclose-gcov.test 2020-07-18 15:04:48 -07:00
Fangrui Song
ca1cc5c4e0 [gcov][test] Call wait() to make gcov-fork.c reliable
If the parent exit before the child, the line counts might be 1.

next:18'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
          26:  1: 21: if (fork() == -1) return 1; // CHECK-NEXT: 1: [[#@LINE]]:
next:18'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
          27:  1: 22: func2(); // CHECK-NEXT: 2: [[#@LINE]]:
next:18'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
          28:  1: 23: return 0; // CHECK-NEXT: 2: [[#@LINE]]:
next:18'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
2020-07-18 11:10:47 -07:00
Vitaly Buka
1cb8cc1fd1 [profile] Enabled test on windows
Works with D34797
2020-07-17 00:05:46 -07:00
Vitaly Buka
b128f719a4 [profile] Disable new failing test from D83967 2020-07-16 19:47:36 -07:00
Min-Yih Hsu
0f6220ddd6 [profile] Move __llvm_profile_raw_version into a separate file
Similar to the reason behind moving __llvm_profile_filename into a
separate file[1]. When users try to use Full LTO with BFD linker to
generate IR level PGO profile, the __llvm_profile_raw_version variable,
which is used for marking instrumentation level, generated by frontend
would somehow conflict with the weak symbol provided by profiling
runtime.

In most of the cases, BFD linkers will pick profiling runtime's weak symbol
as the real definition and thus generate the incorrect instrumentation
level metadata in the final executables.

Moving __llvm_profile_raw_version into a separate file would make
linkers not seeing the weak symbol in the archive unless the frontend
doesn't generate one.

[1] https://reviews.llvm.org/D34797

Differential Revision: https://reviews.llvm.org/D83967
2020-07-16 16:02:04 -07:00
Amara Emerson
85e144329c [profile] Mark gcov test as unsupported on Darwin. 2020-07-04 10:41:27 -07:00
Fangrui Song
1c6e2eceeb [gcov][test] Add UNSUPPORTED: host-byteorder-big-endian to gcov-fork.c
This test strangely failed on ppc64be
http://lab.llvm.org:8011/builders/clang-ppc64be-linux/builds/50913
2020-07-03 17:06:54 -07:00
Fangrui Song
fba8523fb5 [gcov][test] Reorganize some compiler-rt/test/profile tests 2020-07-03 16:17:16 -07:00
Vedant Kumar
47481cbffb [test] Deflake test/profile/ContinuousSyncMode/online-merging.c
This test spawns 32 child processes which race to update counters on
shared memory pages. On some Apple-internal machines, two processes race
to perform an update in approximately 0.5% of the test runs, leading to
dropped counter updates. Deflake the test by using atomic increments.

Tested with:

```
$ for I in $(seq 1 1000); do echo ":: Test run $I..."; ./bin/llvm-lit projects/compiler-rt/test/profile/Profile-x86_64h/ContinuousSyncMode/online-merging.c -av || break; done
```

rdar://64956774
2020-07-02 13:31:56 -07:00
Fangrui Song
48c196f5c8 [gcov] Move llvm_writeout_files from atexit to a static destructor
atexit registered functions run earlier so `__attribute__((destructor))`
annotated functions cannot be tracked.

Set a priority of 100 (compatible with GCC 7 onwards) to track
destructors and destructors whose priorities are greater than 100.

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=7970

Reviewed By: calixte, marco-c

Differential Revision: https://reviews.llvm.org/D82253
2020-07-01 16:41:55 -07:00
Fangrui Song
70f9cfc857 [builtins][test] Delete unneeded file headers
We don't add file headers to tests. The comments are useless as well -
their purpose can be easily inferred from the filenames.
2020-06-16 17:46:22 -07:00
Vitaly Buka
5a3b380f49 Revert "[InstrProfiling] Use !associated metadata for counters, data and values"
This reverts commit 69c5ff4668cd4d1bfb6b45d71e15c12e3a23ae05.
This reverts commit 603d58b5e49c76e4a2e5bf1450b71b100a3396ba.
This reverts commit ba10bedf5631eda3a17df428c88451c754633d23.
This reverts commit 39b3c41b65302a969fa5507402976a255a07c158.
2020-06-10 02:32:50 -07:00
Petr Hosek
69c5ff4668 [InstrProfiling] Use -fuse-ld=lld in instrprof-gc-sections test
This was accidentally omitted in 603d58b leading to a test failure
on some of the bots that don't use lld as the default linker.
2020-06-08 16:36:14 -07:00
Petr Hosek
603d58b5e4 [InstrProfiling] Use !associated metadata for counters, data and values
The !associated metadata may be attached to a global object declaration
with a single argument that references another global object. This
metadata prevents discarding of the global object in linker GC unless
the referenced object is also discarded.

Furthermore, when a function symbol is discarded by the linker, setting
up !associated metadata allows linker to discard counters, data and
values associated with that function symbol. This is not possible today
because there's metadata to guide the linker. This approach is also used
by other instrumentations like sanitizers.

Note that !associated metadata is only supported by ELF, it does not have
any effect on non-ELF targets.

Differential Revision: https://reviews.llvm.org/D76802
2020-06-08 15:07:43 -07:00
Petr Hosek
ba10bedf56 Revert "[InstrProfiling] Use !associated metadata for counters, data and values"
This reverts commit 39b3c41b65302a969fa5507402976a255a07c158 due to
a failing associated.ll test.
2020-06-08 14:38:15 -07:00
Petr Hosek
39b3c41b65 [InstrProfiling] Use !associated metadata for counters, data and values
The !associated metadata may be attached to a global object declaration
with a single argument that references another global object. This
metadata prevents discarding of the global object in linker GC unless
the referenced object is also discarded.

Furthermore, when a function symbol is discarded by the linker, setting
up !associated metadata allows linker to discard counters, data and
values associated with that function symbol. This is not possible today
because there's metadata to guide the linker. This approach is also used
by other instrumentations like sanitizers.

Note that !associated metadata is only supported by ELF, it does not have
any effect on non-ELF targets.

Differential Revision: https://reviews.llvm.org/D76802
2020-06-08 13:35:56 -07:00
Fangrui Song
e3200dab60 [gcov] Support .gcno/.gcda in gcov 8, 9 or 10 compatible formats 2020-06-07 11:27:49 -07:00