Commit Graph

11 Commits

Author SHA1 Message Date
Rafael Espindola e4b0231c63 Make internal/private GVs implicitly dso_local.
While updating clang tests for having clang set dso_local I noticed
that:

- There are *a lot* of tests to update.
- Many of the updates are redundant.

They are redundant because a GV is "obviously dso_local". This patch
starts formalizing that a bit by requiring that internal and private
GVs be dso_local too. Since they all are, we don't have to print
dso_local to the textual representation, making it a bit more compact
and easier to read.

llvm-svn: 322317
2018-01-11 22:15:05 +00:00
Charles Saternos 75da10d1b2 [ThinLTO] Add FunctionAttrs to ThinLTO index
Adds function attributes to index: ReadNone, ReadOnly, NoRecurse, NoAlias. This attributes will be used for future ThinLTO optimizations that will propagate function attributes across modules.

llvm-svn: 310061
2017-08-04 16:00:58 +00:00
Peter Collingbourne 92648c25a4 Bitcode: Write the irsymtab to disk.
Differential Revision: https://reviews.llvm.org/D33973

llvm-svn: 306487
2017-06-27 23:50:11 +00:00
Peter Collingbourne a0f371a106 Bitcode: Add a string table to the bitcode format.
Add a top-level STRTAB block containing a string table blob, and start storing
strings for module codes FUNCTION, GLOBALVAR, ALIAS, IFUNC and COMDAT in
the string table.

This change allows us to share names between globals and comdats as well
as between modules, and improves the efficiency of loading bitcode files by
no longer using a bit encoding for symbol names. Once we start writing the
irsymtab to the bitcode file we will also be able to share strings between
it and the module.

On my machine, link time for Chromium for Linux with ThinLTO decreases by
about 7% for no-op incremental builds or about 1% for full builds. Total
bitcode file size decreases by about 3%.

As discussed on llvm-dev:
http://lists.llvm.org/pipermail/llvm-dev/2017-April/111732.html

Differential Revision: https://reviews.llvm.org/D31838

llvm-svn: 300464
2017-04-17 17:51:36 +00:00
Piotr Padlewski d9830eb79f [thinlto] Basic thinlto fdo heuristic
Summary:
This patch improves thinlto importer
by importing 3x larger functions that are called from hot block.

I compared performance with the trunk on spec, and there
were about 2% on povray and 3.33% on milc. These results seems
to be consistant and match the results Teresa got with her simple
heuristic. Some benchmarks got slower but I think they are just
noisy (mcf, xalancbmki, omnetpp)- running the benchmarks again with
more iterations to confirm. Geomean of all benchmarks including the noisy ones
were about +0.02%.

I see much better improvement on google branch with Easwaran patch
for pgo callsite inlining (the inliner actually inline those big functions)
Over all I see +0.5% improvement, and I get +8.65% on povray.
So I guess we will see much bigger change when Easwaran patch will land
(it depends on new pass manager), but it is still worth putting this to trunk
before it.

Implementation details changes:
- Removed CallsiteCount.
- ProfileCount got replaced by Hotness
- hot-import-multiplier is set to 3.0 for now,
didn't have time to tune it up, but I see that we get most of the interesting
functions with 3, so there is no much performance difference with higher, and
binary size doesn't grow as much as with 10.0.

Reviewers: eraman, mehdi_amini, tejohnson

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D24638

llvm-svn: 282437
2016-09-26 20:37:32 +00:00
Mehdi Amini c3ed48c1bd Reorganize GlobalValueSummary with a "Flags" bitfield.
Right now it only contains the LinkageType, but will be extended
with "hasSection", "isOptSize", "hasInlineAssembly", etc.

Differential Revision: http://reviews.llvm.org/D19404

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267319
2016-04-24 03:18:18 +00:00
Mehdi Amini 68da426eea Move summary creation out of llvm-as into opt
Summary:
Let keep llvm-as "dumb": it converts textual IR to bitcode. This
commit removes the dependency from llvm-as to libLLVMAnalysis.
We'll add back summary in llvm-as if we get to a textual
representation for it at some point. In the meantime, opt seems
like a better place for that.

Reviewers: tejohnson

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D19032

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266131
2016-04-12 21:35:18 +00:00
Teresa Johnson 26ab5772b0 [ThinLTO] Renaming of function index to module summary index (NFC)
(Resubmitting after fixing missing file issue)

With the changes in r263275, there are now more than just functions in
the summary. Completed the renaming of data structures (started in
r263275) to reflect the wider scope. In particular, changed the
FunctionIndex* data structures to ModuleIndex*, and renamed related
variables and comments. Also renamed the files to reflect the changes.

A companion clang patch will immediately succeed this patch to reflect
this renaming.

llvm-svn: 263513
2016-03-15 00:04:37 +00:00
Teresa Johnson cec0cae313 Revert "[ThinLTO] Renaming of function index to module summary index (NFC)"
This reverts commit r263490. Missed a file.

llvm-svn: 263493
2016-03-14 21:18:10 +00:00
Teresa Johnson 892920b358 [ThinLTO] Renaming of function index to module summary index (NFC)
With the changes in r263275, there are now more than just functions in
the summary. Completed the renaming of data structures (started in
r263275) to reflect the wider scope. In particular, changed the
FunctionIndex* data structures to ModuleIndex*, and renamed related
variables and comments. Also renamed the files to reflect the changes.

A companion clang patch will immediately succeed this patch to reflect
this renaming.

llvm-svn: 263490
2016-03-14 21:05:56 +00:00
Teresa Johnson 76a1c1d0ba [ThinLTO] Support for reference graph in per-module and combined summary.
Summary:
This patch adds support for including a full reference graph including
call graph edges and other GV references in the summary.

The reference graph edges can be used to make importing decisions
without materializing any source modules, can be used in the plugin
to make file staging decisions for distributed build systems, and is
expected to have other uses.

The call graph edges are recorded in each function summary in the
bitcode via a list of <CalleeValueIds, StaticCount> tuples when no PGO
data exists, or <CalleeValueId, StaticCount, ProfileCount> pairs when
there is PGO, where the ValueId can be mapped to the function GUID via
the ValueSymbolTable. In the function index in memory, the call graph
edges reference the target via the CalleeGUID instead of the
CalleeValueId.

The reference graph edges are recorded in each summary record with a
list of referenced value IDs, which can be mapped to value GUID via the
ValueSymbolTable.

Addtionally, a new summary record type is added to record references
from global variable initializers. A number of bitcode records and data
structures have been renamed to reflect the newly expanded scope of the
summary beyond functions. More cleanup will follow.

Reviewers: joker.eph, davidxl

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D17212

llvm-svn: 263275
2016-03-11 18:52:24 +00:00