Commit Graph

13 Commits

Author SHA1 Message Date
Vedant Kumar 9a041a7522 [InstrProfiling] Emit the runtime hook when no counters are lowered
The API verification tool tapi has difficulty processing frameworks
which enable code coverage, but which have no code. The profile lowering
pass does not emit the runtime hook in this case because no counters are
lowered.

While the hook is not needed for program correctness (the profile
runtime doesn't have to be linked in), it's needed to allow tapi to
validate the exported symbol set of instrumented binaries.

It was not possible to add a workaround in tapi for empty binaries due
to an architectural issue: tapi generates its expected symbol set before
it inspects a binary. Changing that model has a higher cost than simply
forcing llvm to always emit the runtime hook.

rdar://36076904

Differential Revision: https://reviews.llvm.org/D43794

llvm-svn: 326350
2018-02-28 19:00:08 +00:00
Vedant Kumar 55891fc71e Re-apply "[profiling] Remove dead profile name vars after emitting name data"
This reverts 295092 (re-applies 295084), with a fix for dangling
references from the array of coverage names passed down from frontends.

I missed this in my initial testing because I only checked test/Profile,
and not test/CoverageMapping as well.

Original commit message:

The profile name variables passed to counter increment intrinsics are dead
after we emit the finalized name data in __llvm_prf_nm. However, we neglect to
erase these name variables. This causes huge size increases in the
__TEXT,__const section as well as slowdowns when linker dead stripping is
disabled. Some affected projects are so massive that they fail to link on
Darwin, because only the small code model is supported.

Fix the issue by throwing away the name constants as soon as we're done with
them.

Differential Revision: https://reviews.llvm.org/D29921

llvm-svn: 295099
2017-02-14 20:03:48 +00:00
Vedant Kumar 27ebdf4bcb Revert "[profiling] Remove dead profile name vars after emitting name data"
This reverts commit r295084. There is a test failure on:

http://lab.llvm.org:8011/builders/clang-atom-d525-fedora-rel/builds/2620/

llvm-svn: 295092
2017-02-14 19:08:39 +00:00
Vedant Kumar bb10484662 [profiling] Remove dead profile name vars after emitting name data
The profile name variables passed to counter increment intrinsics are
dead after we emit the finalized name data in __llvm_prf_nm. However, we
neglect to erase these name variables. This causes huge size increases
in the __TEXT,__const section as well as slowdowns when linker dead
stripping is disabled. Some affected projects are so massive that they
fail to link on Darwin, because only the small code model is supported.

Fix the issue by throwing away the name constants as soon as we're done
with them.

Differential Revision: https://reviews.llvm.org/D29921

llvm-svn: 295084
2017-02-14 18:48:48 +00:00
Vedant Kumar de2ae96710 [InstrProf] Add support for dead_strip+live_support functionality
On Darwin, marking a section as "regular,live_support" means that a
symbol in the section should only be kept live if it has a reference to
something that is live. Otherwise, the linker is free to dead-strip it.

Turn this functionality on for the __llvm_prf_data section.

This means that counters and data associated with dead functions will be
removed from dead-stripped binaries. This will result in smaller
profiles and binaries, and should speed up profile collection.

Tested with check-profile, llvm-lit test/tools/llvm-{cov,profdata}, and
check-llvm.

Differential Revision: https://reviews.llvm.org/D25456

llvm-svn: 283947
2016-10-11 21:48:16 +00:00
Xinliang David Li e6b892940f Port InstrProfiling pass to the new pass manager
Differential Revision: http://reviews.llvm.org/D18126

llvm-svn: 266637
2016-04-18 17:47:38 +00:00
Xinliang David Li a82d6c0a4b [PGO] Enable compression in pgo instrumentation
This reduces sizes of instrumented object files, final binaries,
process images, and raw profile data.

The format of the indexed profile data remain the same.

Differential Revision: http://reviews.llvm.org/D16388 
 

llvm-svn: 260117
2016-02-08 18:13:49 +00:00
Xinliang David Li c7018a25c6 [PGO] make profile prefix even shorter and more readable
llvm-svn: 255586
2015-12-15 00:32:56 +00:00
Xinliang David Li 0812747979 [PGO] Shorten profile symbol prefixes
Profile symbols have long prefixes which waste space and creating pressure for linker.
This patch shortens the prefixes to minimal length without losing verbosity.

Differential Revision: http://reviews.llvm.org/D15503

llvm-svn: 255575
2015-12-14 23:26:27 +00:00
Xinliang David Li d1bab96045 [PGO] Stop using invalid char in instr variable names.
Before the patch, -fprofile-instr-generate compile will fail
if no integrated-as is specified when the file contains
any static functions (the -S output is also invalid).

This is the second try. The fix in this patch is very localized.
Only profile symbol names of profile symbols with internal 
linkage are fixed up while initializer of name syms are not 
changes. This means there is no format change nor version bump.

llvm-svn: 255434
2015-12-12 17:28:03 +00:00
Betul Buyukkurt 6fac1741c9 [PGO] Value profiling support
This change introduces an instrumentation intrinsic instruction for
value profiling purposes, the lowering of the instrumentation intrinsic
and raw reader updates. The raw profile data files for llvm-profdata
testing are updated.

llvm-svn: 253484
2015-11-18 18:14:55 +00:00
David Blaikie f72d05bc7b [opaque pointer type] Add textual IR support for explicit type parameter to gep operator
Similar to gep (r230786) and load (r230794) changes.

Similar migration script can be used to update test cases, which
successfully migrated all of LLVM and Polly, but about 4 test cases
needed manually changes in Clang.

(this script will read the contents of stdin and massage it into stdout
- wrap it in the 'apply.sh' script shown in previous commits + xargs to
apply it over a large set of test cases)

import fileinput
import sys
import re

rep = re.compile(r"(getelementptr(?:\s+inbounds)?\s*\()((<\d*\s+x\s+)?([^@]*?)(|\s*addrspace\(\d+\))\s*\*(?(3)>)\s*)(?=$|%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|zeroinitializer|<|\[\[[a-zA-Z]|\{\{)", re.MULTILINE | re.DOTALL)

def conv(match):
  line = match.group(1)
  line += match.group(4)
  line += ", "
  line += match.group(2)
  return line

line = sys.stdin.read()
off = 0
for match in re.finditer(rep, line):
  sys.stdout.write(line[off:match.start()])
  sys.stdout.write(conv(match))
  off = match.end()
sys.stdout.write(line[off:])

llvm-svn: 232184
2015-03-13 18:20:45 +00:00
Justin Bogner 61ba2e3996 InstrProf: An intrinsic and lowering for instrumentation based profiling
Introduce the ``llvm.instrprof_increment`` intrinsic and the
``-instrprof`` pass. These provide the infrastructure for writing
counters for profiling, as in clang's ``-fprofile-instr-generate``.

The implementation of the instrprof pass is ported directly out of the
CodeGenPGO classes in clang, and with the followup in clang that rips
that code out to use these new intrinsics this ends up being NFC.

Doing the instrumentation this way opens some doors in terms of
improving the counter performance. For example, this will make it
simple to experiment with alternate lowering strategies, and allows us
to try handling profiling specially in some optimizations if we want
to.

Finally, this drastically simplifies the frontend and puts all of the
lowering logic in one place.

llvm-svn: 223672
2014-12-08 18:02:35 +00:00