Xinliang David Li 859c330e8f [PGO] Improve Indexed Profile Reader efficiency ... With the support of value profiling added, the Indexed prof reader gets less efficient. The prof reader initialization used to be just reading the file header, but with VP support added, initialization needs to walk through all profile keys of ondisk hash table resulting in very poor locality and large memory increase (keys are stored together with the profile data in the mapped profile buffer). Even worse, when the reader is used by the compiler (not llvm-profdata too), the penalty becomes very high as compilation of each single module requires touching profile data buffer for the whole program. In this patch, the icall target values (MD5hash) are no longer eargerly converted back to name strings when the data is read into memory. New interface is added to to profile reader so that InstrProfSymtab can be lazily created for Indexed profile reader on-demand. Creating of the symtab is intended to be used by llvm-profdata tool for symbolic dumping of VP data. It can be used with compiler (for legacy out of tree uses) too but not recommended due to compile time and memory reasons mentioned above. Some other cleanups are also included: Function Addr to md5 map is now consolated into InstrProfSymtab. InstrProfStringtab is no longer used and eliminated. llvm-svn: 256114		2015-12-20 06:22:13 +00:00
..
CMakeLists.txt
llvm-profdata.cpp	[PGO] Improve Indexed Profile Reader efficiency	2015-12-20 06:22:13 +00:00
LLVMBuild.txt
Makefile