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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| .. | ||
| CMakeLists.txt | ||
| GCDAProfiling.c | ||
| InstrProfiling.c | ||
| InstrProfiling.h | ||
| InstrProfilingBuffer.c | ||
| InstrProfilingFile.c | ||
| InstrProfilingInternal.c | ||
| InstrProfilingInternal.h | ||
| InstrProfilingMerge.c | ||
| InstrProfilingMergeFile.c | ||
| InstrProfilingNameVar.c | ||
| InstrProfilingPlatformDarwin.c | ||
| InstrProfilingPlatformFuchsia.c | ||
| InstrProfilingPlatformLinux.c | ||
| InstrProfilingPlatformOther.c | ||
| InstrProfilingPlatformWindows.c | ||
| InstrProfilingPort.h | ||
| InstrProfilingRuntime.cpp | ||
| InstrProfilingUtil.c | ||
| InstrProfilingUtil.h | ||
| InstrProfilingValue.c | ||
| InstrProfilingVersionVar.c | ||
| InstrProfilingWriter.c | ||
| WindowsMMap.c | ||
| WindowsMMap.h | ||