2 Commits

Author	SHA1	Message	Date
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	b5ef137c11	[gcov] Increment counters with atomicrmw if -fsanitize=thread ... Without this patch, `clang --coverage -fsanitize=thread` may fail spuriously because non-atomic counter increments can be detected as data races.	2020-08-28 16:32:35 -07:00