Commit Graph

29 Commits

Author SHA1 Message Date
Duncan P. N. Exon Smith b3a66691f8 IR: Make metadata typeless in assembly, clang side
Match LLVM changes from r224257.

llvm-svn: 224259
2014-12-15 19:10:08 +00:00
Justin Bogner 970ac60573 InstrProf: Use LLVM's -instrprof pass for profiling
The logic for lowering profiling counters has been moved to an LLVM
pass. Emit the intrinsics rather than duplicating the whole pass in
clang.

llvm-svn: 223683
2014-12-08 19:04:51 +00:00
Justin Bogner 111c6533c2 InstrProf: Use the same names for variables as we use in the profile
There's no need to use different names for the local variables than we
use in the profile itself, and it's a bit simpler and easier to debug
if we're consistent.

llvm-svn: 223173
2014-12-02 23:15:30 +00:00
Justin Bogner 9c6818ef00 InstrProf: Update for LLVM API change
We've added support for a multiple functions with the same name in
LLVM's profile data, so the lookup returning the function hash it
found doesn't make sense anymore. Update to pass in the hash we
expect.

This also adds a test that the version 1 format is still readable,
since the new API is expected to handle that.

llvm-svn: 214586
2014-08-01 22:50:16 +00:00
Justin Bogner 40b8ba1496 CodeGen: Improve warnings about uninstrumented files when profiling
Improve the warning when building with -fprofile-instr-use and a file
appears not to have been profiled at all. This keys on whether a
function is defined in the main file or not to avoid false negatives
when one includes a header with functions that have been profiled.

llvm-svn: 211760
2014-06-26 01:45:07 +00:00
Duncan P. N. Exon Smith 9121220804 InstrProf: Set profile data to visibility hidden
Shared objects are fairly broken for InstrProf right now -- a follow-up
commit in compiler-rt will fix the rest of this.

The main problem here is that at link time, profile data symbols in the
shared object might get used instead of symbols from the main
executable, creating invalid profile data sections.

<rdar://problem/16918688>

llvm-svn: 208939
2014-05-16 01:24:00 +00:00
Justin Bogner 3212b18bbf CodeGen: Avoid instrumenting implicit Decls more effectively
We don't assign counters for implicit Decls, but we were emitting code
to increment the (non-existent) counters and adding empty counter
lists in the output. This fixes the checks in assignRegionCounters and
emitInstrumentationData to do the right thing, and adds an assert for
the pathological case of emitting zero counters.

llvm-svn: 207203
2014-04-25 07:20:05 +00:00
Justin Bogner 534f14abe7 test: Use llvm-profdata merge in Profile tests
In preparation for using a binary format for instrumentation based
profiling, explicitly treat the test inputs as text and transform them
before running. This will allow us to leave the checked in files in
human readable format once the instrumentation format is binary.

No functional change.

llvm-svn: 206509
2014-04-17 22:49:06 +00:00
Keith Walker 8ff56f6080 Fix Profile:cxx-lambda.cpp test for targets that do not generate zeroext
Change an expected match to allow for the fact that some targets
may not generated the zeroext operation.

llvm-svn: 206467
2014-04-17 13:04:53 +00:00
Duncan P. N. Exon Smith 4bc7731a29 InstrProf: Calculate a better function hash
The function hash should change when control flow changes.  This patch
hashes the type of each AST node that affects counters, rather than just
counting how many there are.  These types are combined into a small
enumerator that currently has 16 values.

The new hash algorithm packs the enums for consecutively visited types
into a `uint64_t`.  In order to save space for new types, the types are
assumed to be 6-bit values (instead of 4-bit).  In order to minimize
overhead for functions with little control flow, the `uint64_t` is used
directly as a hash if it never fills up; if it does, it's passed through
an MD5 context.

<rdar://problem/16435801>

llvm-svn: 206397
2014-04-16 16:03:27 +00:00
Justin Bogner e2ef2a09ef CodeGen: Emit warnings for out of date profile data during PGO
This adds a warning that triggers when profile data doesn't match for
the source that's being compiled with -fprofile-instr-use=. This fires
only once per translation unit, as warning on every mismatched
function would be quite noisy.

llvm-svn: 206322
2014-04-15 21:22:35 +00:00
Justin Bogner 81ab90f7ed CodeGen: Handle CapturedStmt in instrumentation based profiling
CapturedStmt was being ignored by instrumentation based profiling, and
its counters attributed to the containing function. Instead, we need
to treat this as a top level entity, like we do with blocks.

llvm-svn: 206231
2014-04-15 00:50:54 +00:00
Justin Bogner b1966291de CodeGen: Test instrumentation based profiling of templates
Make sure that templates are handled correctly by profile
instrumentation.

llvm-svn: 206091
2014-04-12 00:54:06 +00:00
Justin Bogner 191ec63b71 CodeGen: Fix handling of C++11 lambdas in profiling
Until now we were generating duplicate counters for lambdas: one set
in the function where the lambda was declared and another for the
lambda itself. Instead, we should skip over the bodies of lambdas in
their containing contexts.

llvm-svn: 206081
2014-04-11 23:06:35 +00:00
Justin Bogner 53c55d993f CodeGen: Handle binary conditional operators in PGO instrumentation
This treats binary conditional operators in the same way as ternary
conditional operators for instrumentation based profiling.

llvm-svn: 206021
2014-04-11 06:10:10 +00:00
Justin Bogner f3aefca7c1 CodeGen: Don't create branch weight metadata from empty profiles
If all of our weights are zero when calculating branch weights, it
means we haven't profiled the code in question. Avoid creating a
metadata node that says all branches are equally likely in this case.

The test also checks constructs that hit the other createBranchWeights
overload. These were already working.

llvm-svn: 205606
2014-04-04 02:48:51 +00:00
Duncan P. N. Exon Smith d971cd1b18 InstrProf: Emit runtime hook directly in IRGen
-u behaviour is apparently not portable between linkers (see cfe-commits
discussions for r204379 and r205012).  I've moved the logic to IRGen,
where it should have been in the first place.

I don't have a Linux system to test this on, so it's possible this logic
*still* doesn't pull in the instrumented profiling runtime on Linux.

I'm in the process of getting tests going on the compiler-rt side
(llvm-commits "[PATCH] InstrProf: Add initial compiler-rt test").  Once
we have tests for the full flow there, the runtime logic should get a
whole lot less brittle.

<rdar://problem/16458307>

llvm-svn: 205023
2014-03-28 17:53:22 +00:00
Bob Wilson 0ed74d9634 [PGO] Add simplified branch weights for Objective-C for-collection loops.
Conceptually one of these loops is just a while-loop, but the actual code-gen
is more complicated. We don't instrument all the different control flow edges
to get accurate counts for each conditional branch, nor do I think it makes
sense to do so. Instead, make the simplifying assumption that the loop behaves
like a while-loop. Use the same branch weights for the first check for an
empty collection as would be used for the back-edge of a while loop, and use
that same weighting for the innermost loop, ignoring the possibility that there
may be some extra code to go fetch more elements.

llvm-svn: 204767
2014-03-25 23:26:31 +00:00
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