Ping. Teresa On Wed, May 14, 2014 at 4:39 PM, Teresa Johnson <tejohn...@google.com> wrote: > This patch applies profile fixups to COMDATs on the dyn ipa callgraph > at the end of LIPO module grouping (either in the profile gen run or > in gcov-tool). This is to address issues with missing profiles in the > out-of-line COMDAT copies not selected by the linker, and indirect > call profiles that target a module not included in the module group. > By default, both fixups are enabled, but can be controlled by a > profile-gen parameter, an environment variable, and a gcov-tool > option. > > The fixups assume that functions with the same lineno and cfg checksum > are copies of the same COMDAT. This is made more likely by ensuring > that in LIPO mode we include the full mangled name in the > lineno_checksum. > > For the counter fixup, we merge all non-zero profiles with matching > checksums and copy the merged profile into copies with all-zero > profiles. > > For the indirect counter fixup, if an indirect call profile target is > not in the module group, we look for a matching checksum copy in the > primary module and if exactly one is found we change the target to > that. > > If any fixups are applied, the gcda files are rewritten after module grouping. > > This also required a couple of other changes to the optimizer. During > cgraph node resolution, we were arbitrarily selecting a copy that had > non-zero profiles. Now there are many more to choose from, so we will > prefer the primary module copy if it is non-zero. Also, during cloning > for inlining, we only want to update the profile on the callee node if > we are inlining into the resolved node caller node. We were already > doing this for AutoFDO, and need to do this here now that many node > copies have the same profile. > > Patch attached. Tested with regression tests and internal benchmarks. > Ok for google branches? > > Thanks, > Teresa > > > > -- > Teresa Johnson | Software Engineer | tejohn...@google.com | 408-460-2413
-- Teresa Johnson | Software Engineer | tejohn...@google.com | 408-460-2413
