[profile] Fix value profile runtime merging issues
This patch fixes the following issues:
(1) The strong definition of the merge hook function was not working which
breaks the online value profile merging. This patch removes the weak
attribute of VPMergeHook and assigns the value dynamically.
(2) Truncate the proifle file so that we don't have garbage data at the end of
the file.
(3) Add new __llvm_profile_instrument_target_value() interface to do the value
profile update in batch. This is needed as the original incremental by 1
in __llvm_profile_instrument_target() is too slow for online merge.
Differential Revision: https://reviews.llvm.org/D44847
llvm-svn: 328987
diff --git a/compiler-rt/lib/profile/InstrProfilingFile.c b/compiler-rt/lib/profile/InstrProfilingFile.c
index d7c0abb..6e6b8fa 100644
--- a/compiler-rt/lib/profile/InstrProfilingFile.c
+++ b/compiler-rt/lib/profile/InstrProfilingFile.c
@@ -183,8 +183,12 @@
/* Now start merging */
__llvm_profile_merge_from_buffer(ProfileBuffer, ProfileFileSize);
- (void)munmap(ProfileBuffer, ProfileFileSize);
+ // Truncate the file in case merging of value profile did not happend to
+ // prevent from leaving garbage data at the end of the profile file.
+ ftruncate(fileno(ProfileFile), __llvm_profile_get_size_for_buffer());
+
+ (void)munmap(ProfileBuffer, ProfileFileSize);
*MergeDone = 1;
return 0;
@@ -234,6 +238,7 @@
FILE *OutputFile;
int MergeDone = 0;
+ VPMergeHook = &lprofMergeValueProfData;
if (!doMerging())
OutputFile = fopen(OutputName, "ab");
else