forked from OSchip/llvm-project
11d3074267
Use the llvm flag `-pgo-function-entry-coverage` to create single byte "counters" to track functions coverage. This mode has significantly less size overhead in both code and data because * We mark a function as "covered" with a store instead of an increment which generally requires fewer assembly instructions * We use a single byte per function rather than 8 bytes per block The trade off of course is that this mode only tells you if a function has been covered. This is useful, for example, to detect dead code. When combined with debug info correlation [0] we are able to create an instrumented Clang binary that is only 150M (the vanilla Clang binary is 143M). That is an overhead of 7M (4.9%) compared to the default instrumentation (without value profiling) which has an overhead of 31M (21.7%). [0] https://groups.google.com/g/llvm-dev/c/r03Z6JoN7d4 Reviewed By: kyulee Differential Revision: https://reviews.llvm.org/D116180 |
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| .. | ||
| ContinuousSyncMode | ||
| Darwin | ||
| Inputs | ||
| Linux | ||
| Posix | ||
| Windows | ||
| CMakeLists.txt | ||
| coverage-inline.cpp | ||
| coverage_comments.cpp | ||
| coverage_emptylines.cpp | ||
| gcc-flag-compatibility.test | ||
| gcov-__gcov_flush-terminate.c | ||
| gcov-basic.c | ||
| gcov-complex-line.c | ||
| gcov-dump-and-remove.c | ||
| infinite_loop.c | ||
| instrprof-basic.c | ||
| instrprof-bufferio.c | ||
| instrprof-coverage.c | ||
| instrprof-darwin-dead-strip.c | ||
| instrprof-darwin-exports.c | ||
| instrprof-dump.c | ||
| instrprof-error.c | ||
| instrprof-gc-sections.c | ||
| instrprof-gcov-exceptions.test | ||
| instrprof-gcov-multiple-bbs-single-line.test | ||
| instrprof-gcov-multithread_fork.test | ||
| instrprof-gcov-one-line-function.test | ||
| instrprof-gcov-switch.test | ||
| instrprof-gcov-two-objects.test | ||
| instrprof-get-filename.c | ||
| instrprof-hostname.c | ||
| instrprof-icall-promo.test | ||
| instrprof-lto-pgogen.c | ||
| instrprof-merge-entry-cover.c | ||
| instrprof-merge-match.test | ||
| instrprof-merge.c | ||
| instrprof-merging.cpp | ||
| instrprof-order-file.test | ||
| instrprof-override-filename-then-reset-default.c | ||
| instrprof-override-filename-with-env.c | ||
| instrprof-override-filename.c | ||
| instrprof-path.c | ||
| instrprof-reset-counters.c | ||
| instrprof-set-dir-mode.c | ||
| instrprof-set-file-object-merging.c | ||
| instrprof-set-file-object.c | ||
| instrprof-set-filename-then-reset-default.c | ||
| instrprof-set-filename.c | ||
| instrprof-tmpdir.c | ||
| instrprof-value-prof-2.c | ||
| instrprof-value-prof-evict.test | ||
| instrprof-value-prof-reset.c | ||
| instrprof-value-prof.c | ||
| instrprof-value-prof.test | ||
| instrprof-version-mismatch.c | ||
| instrprof-without-libc.c | ||
| instrprof-write-buffer-internal.c | ||
| instrprof-write-file-atexit-explicitly.c | ||
| instrprof-write-file-only.c | ||
| instrprof-write-file.c | ||
| lit.cfg.py | ||
| lit.site.cfg.py.in | ||
| profile_test.h | ||
| runtime_infinite.c | ||