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* Revert "[Coverage] Revise format to reduce binary size"Vedant Kumar2019-12-041-59/+98
| | | | | | | | | | This reverts commit e18531595bba495946aa52c0a16b9f9238cff8bc. On Windows, there is an error: http://lab.llvm.org:8011/builders/sanitizer-windows/builds/54963/steps/stage%201%20check/logs/stdio error: C:\b\slave\sanitizer-windows\build\stage1\projects\compiler-rt\test\profile\Profile-x86_64\Output\instrprof-merging.cpp.tmp.v1.o: Failed to load coverage: Malformed coverage data
* [Coverage] Revise format to reduce binary sizeVedant Kumar2019-12-041-98/+59
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Revise the coverage mapping format to reduce binary size by: 1. Naming function records and marking them `linkonce_odr`, and 2. Compressing filenames. This shrinks the size of llc's coverage segment by 82% (334MB -> 62MB) and speeds up end-to-end single-threaded report generation by 10%. For reference the compressed name data in llc is 81MB (__llvm_prf_names). Rationale for changes to the format: - With the current format, most coverage function records are discarded. E.g., more than 97% of the records in llc are *duplicate* placeholders for functions visible-but-not-used in TUs. Placeholders *are* used to show under-covered functions, but duplicate placeholders waste space. - We reached general consensus about giving (1) a try at the 2017 code coverage BoF [1]. The thinking was that using `linkonce_odr` to merge duplicates is simpler than alternatives like teaching build systems about a coverage-aware database/module/etc on the side. - Revising the format is expensive due to the backwards compatibility requirement, so we might as well compress filenames while we're at it. This shrinks the encoded filenames in llc by 86% (12MB -> 1.6MB). See CoverageMappingFormat.rst for the details on what exactly has changed. Fixes PR34533 [2], hopefully. [1] http://lists.llvm.org/pipermail/llvm-dev/2017-October/118428.html [2] https://bugs.llvm.org/show_bug.cgi?id=34533 Differential Revision: https://reviews.llvm.org/D69471
* [Coverage] Use gap regions to select better line exec countsVedant Kumar2017-09-181-3/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | After clang started emitting deferred regions (r312818), llvm-cov has had a hard time picking reasonable line execuction counts. There have been one or two generic improvements in this area (e.g r310012), but line counts can still report coverage for whitespace instead of code (llvm.org/PR34612). To fix the problem: * Introduce a new region kind so that frontends can explicitly label gap areas. This is done by changing the encoding of the columnEnd field of MappingRegion. This doesn't substantially increase binary size, and makes it easy to maintain backwards-compatibility. * Don't set the line count to a count from a gap area, unless the count comes from a wrapped segment. * Don't highlight gap areas as uncovered. Fixes llvm.org/PR34612. llvm-svn: 313597
* fix some typos in the docSylvestre Ledru2017-01-141-1/+1
| | | | llvm-svn: 292014
* Removes a warning about duplicate label named _strings from CommandLine.rst.Aaron Ballman2016-07-231-1/+1
| | | | llvm-svn: 276530
* [docs] Corrections w.r.t V2 of the coverage mapping formatVedant Kumar2016-03-281-3/+3
| | | | llvm-svn: 264679
* Fix some typos in the llvm docSylvestre Ledru2016-02-141-1/+1
| | | | llvm-svn: 260855
* [PGO] Enable compression in pgo instrumentationXinliang David Li2016-02-081-9/+19
| | | | | | | | | | | | 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
* [Coverage] Fix more bugs in covmap V1 documentationXinliang David Li2016-01-271-8/+11
| | | | llvm-svn: 258906
* More fix to coverage documentationXinliang David Li2016-01-061-7/+19
| | | | llvm-svn: 256895
* Update documantationXinliang David Li2016-01-041-5/+9
| | | | llvm-svn: 256774
* Fix Sphinx error about duplicate label in CommandLine.rst:1560 and ↵Hans Wennborg2015-07-141-1/+1
| | | | | | CoverageMappingFormat.rst llvm-svn: 242245
* Docs: add documentation for the coverage mapping format.Alex Lorenz2014-08-191-0/+576
Differential Revision: http://reviews.llvm.org/D4729 llvm-svn: 215990
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