Commit Graph

111 Commits

Author SHA1 Message Date
Duncan P. N. Exon Smith 7c41451bc9 PGO: Don't define instrumentation data available_externally
Variables with available_externally linkage can be dropped at will.
This causes link errors, since there are still references to the
instrumentation!  linkonce_odr is almost equivalent, so use that
instead.

As a drive-by fix (I don't have an Elf system, so I'm not sure how to
write a testcase), use linkonce linkage for the instrumentation of
extern_weak functions.

<rdar://problem/15943240>

llvm-svn: 204408
2014-03-20 22:50:08 +00:00
Duncan P. N. Exon Smith a7807637bf PGO: Change runtime prefix from pgo to profile
These functions are in the profile runtime.  PGO comes later.

Unfortunately, there's only room for 16 characters in a Darwin section,
so use __llvm_prf_ instead of __llvm_profile_ for section names.

<rdar://problem/15943240>

llvm-svn: 204390
2014-03-20 20:00:41 +00:00
Justin Bogner b4416f58d5 CodeGen: Include a function hash in instrumentation based profiling
The hash itself is still the number of counters, which isn't all that
useful, but this separates the API changes from the actual
implementation of the hash and will make it easier to transition to
the ProfileData library once it's implemented.

llvm-svn: 204186
2014-03-18 21:58:06 +00:00
Duncan P. N. Exon Smith 2fe531cb07 PGO: Statically generate data structures
In instrumentation-based profiling, we need a set of data structures to
represent the counters.  Previously, these were built up during static
initialization.  Now, they're shoved into a specially-named section so
that they show up as an array.

As a consequence of the reorganizing symbols, instrumentation data
structures for linkonce functions are now correctly coalesced.

This is the first step in a larger project to minimize runtime overhead
and dependencies in instrumentation-based profilng.  The larger picture
includes removing all initialization overhead and making the dependency
on libc optional.

<rdar://problem/15943240>

llvm-svn: 204080
2014-03-17 21:18:30 +00:00
Justin Bogner d66a17d0a3 Revert "CodeGen: Use a binary format for instrumentation based profiling"
I've clearly done something wrong with how to get this to link
correctly. Reverting for now.

This reverts commit r203711.

llvm-svn: 203712
2014-03-12 21:06:31 +00:00
Justin Bogner ff9a058267 CodeGen: Use a binary format for instrumentation based profiling
This updates CodeGenPGO to use the ProfileDataReader introduced to
llvm in r203703 and the new API for writing out the profile introduced
to compiler-rt in r203710.

llvm-svn: 203711
2014-03-12 20:53:16 +00:00
Duncan P. N. Exon Smith 5c17f8a7e0 PGO: appease the bots after r203592
llvm-svn: 203618
2014-03-11 23:12:31 +00:00
Duncan P. N. Exon Smith 0bc22877a2 PGO: Clarify the testing README
<rdar://problem/16276448>

llvm-svn: 203593
2014-03-11 18:18:12 +00:00
Duncan P. N. Exon Smith 38402dc917 PGO: Scale large counters down to 32-bits
PGO counters are 64-bit and branch weights are 32-bit.  Scale them down
when necessary, instead of just taking the lower 32 bits.

<rdar://problem/16276448>

llvm-svn: 203592
2014-03-11 18:18:10 +00:00
Justin Bogner ffaa2330b9 test: Regenerate profile data for PGO tests
Some of this data had gotten out of date, so we weren't quite testing
what we thought we were. This also moves the outdated data test to its
own file to simplify regenerating the test data.

llvm-svn: 203546
2014-03-11 06:49:34 +00:00
Justin Bogner 52a6a97d70 test: Give instrumentation based profiling tests their own directory
These tests are logically related, but they're spread about several
different CodeGen directories. Consolidate them in one place to make
them easier to manage.

llvm-svn: 203541
2014-03-11 04:37:49 +00:00