23 Commits

Author SHA1 Message Date
Jessica Paquette
d38484aa0c [MachineOutliner] Recommit r312194, missed optimization remarks
Before, this commit caused a buildbot failure:

http://bb.pgr.jp/builders/test-llvm-i686-linux-RA/builds/6026/steps/test_llvm/logs/LLVM%20%3A%3A%20CodeGen__AArch64__machine-outliner-remarks.ll

This was caused by the Key value in DiagnosticInfoOptimizationBase being
deallocated before emitting the remarks defined in MachineOutliner.cpp. As of
r312277 this should no longer be an issue.
 

llvm-svn: 312280
2017-08-31 21:02:45 +00:00
Daniel Jasper
e14f6c502a Revert r312194: "[MachineOutliner] Add missed optimization remarks for the outliner."
Breaks on buildbot:
http://bb.pgr.jp/builders/test-llvm-i686-linux-RA/builds/6026/steps/test_llvm/logs/LLVM%20%3A%3A%20CodeGen__AArch64__machine-outliner-remarks.ll

llvm-svn: 312219
2017-08-31 06:22:35 +00:00
Jessica Paquette
87db9a2b5c [MachineOutliner] Add missed optimization remarks for the outliner.
This adds missed optimization remarks which report viable candidates that
were not outlined because they would increase code size.

Other remarks will come in separate commits.

This will help to diagnose code size regressions and changes in outliner
behaviour in projects using the outliner.

https://reviews.llvm.org/D37085

llvm-svn: 312194
2017-08-30 23:31:49 +00:00
Jessica Paquette
819dc522cd [MachineOutliner] Only outline candidates of length >= 2
Since we don't factor in instruction lengths into outlining calculations
right now, it's never the case that a candidate could have length < 2.

Thus, we should quit early when we see such candidates.

llvm-svn: 310894
2017-08-14 22:57:41 +00:00
Jessica Paquette
09730f1b79 [MachineOutliner] NFC: Change IsTailCall to a call class + frame class
This commit

- Removes IsTailCall and replaces it with a target-defined unsigned
- Refactors getOutliningCallOverhead and getOutliningFrameOverhead so that they don't use IsTailCall
- Adds a call class + frame class classification to OutlinedFunction and Candidate respectively

This accomplishes a couple things.

Firstly, we don't need the notion of *tail call* in the general outlining algorithm.

Secondly, we now can have different "outlining classes" for each candidate within a set of candidates.
This will make it easy to add new ways to outline sequences for certain targets and dynamically choose
an appropriate cost model for a sequence depending on the context that that sequence lives in.

Ultimately, this should get us closer to being able to do something like, say avoid saving the link
register when outlining AArch64 instructions.

llvm-svn: 309475
2017-07-29 02:55:46 +00:00
Jessica Paquette
38606d229d [MachineOutliner] NFC: Comment tidying
The comment on describing the suffix tree had some pruning
stuff that was out of date in it.

Also fixed some typos.

llvm-svn: 309365
2017-07-28 05:59:30 +00:00
Jessica Paquette
ffc8e4d730 [MachineOutliner] NFC: Split up getOutliningBenefit
This is some more cleanup in preparation for some actual
functional changes. This splits getOutliningBenefit into
two cost functions: getOutliningCallOverhead and
getOutliningFrameOverhead. These functions return the
number of instructions that would be required to call
a specific function and the number of instructions
that would be required to construct a frame for a
specific funtion. The actual outlining benefit logic
is moved into the outliner, which calls these functions.

The goal of refactoring getOutliningBenefit is to:

- Get us closer to getting rid of the IsTailCall flag

- Further split up "target-specific" things and
"general algorithm" things

llvm-svn: 309356
2017-07-28 03:21:58 +00:00
Jessica Paquette
45e73ea26c [MachineOutliner] Cleanup: move findCandidates out of suffix tree
Doing some cleanup in preparation for some functional changes.
This commit moves findCandidates out of the suffix tree and into the
MachineOutliner class. This is much easier to follow, and removes
the burden of candidate choice from the suffix tree.

It also adds a couple FIXMEs and simplifies building outlined function
names.

llvm-svn: 309334
2017-07-27 23:24:43 +00:00
Matthias Braun
17b01651c8 CodeGen: Refactor MIR parsing
When parsing .mir files immediately construct the MachineFunctions and
put them into MachineModuleInfo.

This allows us to get rid of the delayed construction (and delayed error
reporting) through the MachineFunctionInitialzier interface.

Differential Revision: https://reviews.llvm.org/D33809

llvm-svn: 304758
2017-06-06 00:44:35 +00:00
Matthias Braun
120c5b7053 CodeGen: Rename DEBUG_TYPE to match passnames
Rename the DEBUG_TYPE to match the names of corresponding passes where
it makes sense. Also establish the pattern of simply referencing
DEBUG_TYPE instead of repeating the passname where possible.

llvm-svn: 303921
2017-05-25 21:26:32 +00:00
Serge Guelton
6ca59da244 Module::getOrInsertFunction is using C-style vararg instead of variadic templates.
From a user prospective, it forces the use of an annoying nullptr to mark the end of the vararg, and there's not type checking on the arguments.
The variadic template is an obvious solution to both issues.

Differential Revision: https://reviews.llvm.org/D31070

llvm-svn: 299949
2017-04-11 15:01:18 +00:00
Diana Picus
14168afb62 Revert "Turn some C-style vararg into variadic templates"
This reverts commit r299925 because it broke the buildbots. See e.g.
http://lab.llvm.org:8011/builders/clang-cmake-armv7-a15/builds/6008

llvm-svn: 299928
2017-04-11 10:07:12 +00:00
Serge Guelton
0c5a821318 Turn some C-style vararg into variadic templates
Module::getOrInsertFunction is using C-style vararg instead of
variadic templates.

From a user prospective, it forces the use of an annoying nullptr
to mark the end of the vararg, and there's not type checking on the
arguments. The variadic template is an obvious solution to both
issues.

llvm-svn: 299925
2017-04-11 08:36:52 +00:00
Mehdi Amini
176fa1e694 Revert "Turn some C-style vararg into variadic templates"
This reverts commit r299699, the examples needs to be updated.

llvm-svn: 299702
2017-04-06 20:23:57 +00:00
Mehdi Amini
fc06818ec6 Turn some C-style vararg into variadic templates
Module::getOrInsertFunction is using C-style vararg instead of
variadic templates.

From a user prospective, it forces the use of an annoying nullptr
to mark the end of the vararg, and there's not type checking on the
arguments. The variadic template is an obvious solution to both
issues.

Patch by: Serge Guelton <serge.guelton@telecom-bretagne.eu>

Differential Revision: https://reviews.llvm.org/D31070

llvm-svn: 299699
2017-04-06 20:09:31 +00:00
Jessica Paquette
aa9133539b [Outliner] Remove unused lambda capture.
Remove an unused lambda capture that made some bots unhappy.

llvm-svn: 298651
2017-03-23 22:17:20 +00:00
Jessica Paquette
567943a73f [Outliner] Fix compile-time overhead for candidate choice
The old candidate collection method in the outliner caused some very large
regressions in compile time on large tests. For MultiSource/Benchmarks/7zip it
caused a 284.07 s or 1156% increase in compile time. On average, using the
SingleSource/MultiSource tests, it caused an average increase of 8 seconds in
compile time (something like 1000%).

This commit replaces that candidate collection method with a new one which
only visits each node in the tree once. This reduces the worst compile time
increase (still 7zip) to a 0.542 s overhead (22%) and the average compile time
increase on SingleSource and MultiSource to 0.018 s (4%).

llvm-svn: 298648
2017-03-23 21:27:38 +00:00
Jessica Paquette
ad5647725b [Outliner] Add tail call support
This commit adds tail call support to the MachineOutliner pass. This allows
the outliner to insert jumps rather than calls in areas where tail calling is
possible. Outlined tail calls include the return or terminator of the basic
block being outlined from.

Tail call support allows the outliner to take returns and terminators into
consideration while finding candidates to outline. It also allows the outliner
to save more instructions. For example, in the X86-64 outliner, a tail called
outlined function saves one instruction since no return has to be inserted.

llvm-svn: 297653
2017-03-13 18:39:33 +00:00
Simon Pilgrim
070cebbdde Fix -Wsentinel warning
llvm-svn: 297560
2017-03-11 12:56:02 +00:00
Jessica Paquette
a6024d5e77 [Outliner] Fix memory leak in suffix tree.
This commit changes the BumpPtrAllocator for suffix tree nodes to a SpecificBumpPtrAllocator.
Before, node construction was leaking memory because of the DenseMap in SuffixTreeNodes.
Changing this to a SpecificBumpPtrAllocator allows this memory to properly be released.

llvm-svn: 297319
2017-03-08 23:55:33 +00:00
Jessica Paquette
f1e9ef68dc [Outliner] Fixed Asan bot failure in r296418
Fixed the asan bot failure which led to the last commit of the outliner being reverted.
The change is in lib/CodeGen/MachineOutliner.cpp in the SuffixTree's constructor. LeafVector
is no longer initialized using reserve but just a standard constructor.

llvm-svn: 297081
2017-03-06 21:31:18 +00:00
Matthias Braun
174ca3760f Revert "Add MIR-level outlining pass"
Revert Machine Outliner for now, as it breaks the asan bot.

This reverts commit r296418.

llvm-svn: 296426
2017-02-28 02:24:30 +00:00
Matthias Braun
00b30110fb Add MIR-level outlining pass
This is a patch for the outliner described in the RFC at:
http://lists.llvm.org/pipermail/llvm-dev/2016-August/104170.html

The outliner is a code-size reduction pass which works by finding
repeated sequences of instructions in a program, and replacing them with
calls to functions. This is useful to people working in low-memory
environments, where sacrificing performance for space is acceptable.

This adds an interprocedural outliner directly before printing assembly.
For reference on how this would work, this patch also includes X86
target hooks and an X86 test.

The outliner is run like so:

clang -mno-red-zone -mllvm -enable-machine-outliner file.c

Patch by Jessica Paquette<jpaquette@apple.com>!

rdar://29166825

Differential Revision: https://reviews.llvm.org/D26872

llvm-svn: 296418
2017-02-28 00:33:32 +00:00