Commit Graph

60 Commits

Author SHA1 Message Date
Adrian Prantl 4dfcc4a788 Remove @brief commands from doxygen comments, too.
This is a follow-up to r331272.

We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.

Patch produced by
  for i in $(git grep -l '\@brief'); do perl -pi -e 's/\@brief //g' $i & done

https://reviews.llvm.org/D46290

llvm-svn: 331275
2018-05-01 16:10:38 +00:00
Adrian Prantl 5f8f34e459 Remove \brief commands from doxygen comments.
We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.

Patch produced by

  for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done

Differential Revision: https://reviews.llvm.org/D46290

llvm-svn: 331272
2018-05-01 15:54:18 +00:00
Nicolai Haehnle eb7311ffb1 StructurizeCFG: Test for branch divergence correctly
Fixes cases like the new test @nonuniform. In that test, %cc itself
is a uniform value; however, when reading it after the end of the loop in
basic block %if, its value is effectively non-uniform, so the branch is
non-uniform.

This problem was encountered in
https://bugs.freedesktop.org/show_bug.cgi?id=103743; however, this change
in itself is not sufficient to fix that bug, as there is another issue
in the AMDGPU backend.

As discovered after committing an earlier version of this change, this
exposes a subtle interaction between this pass and DivergenceAnalysis:
since we remove and re-create branch instructions, we can no longer rely
on DivergenceAnalysis for branches in subregions that were already
processed by the pass.

Explicitly remove branch instructions from DivergenceAnalysis to
avoid dangling pointers as a matter of defensive programming, and
change how we detect non-uniform subregions.

Change-Id: I32bbffece4a32f686fab54964dae1a5dd72949d4

Differential Revision: https://reviews.llvm.org/D43743

llvm-svn: 329165
2018-04-04 10:58:15 +00:00
David Blaikie a373d18eb7 Transforms: Introduce Transforms/Utils.h rather than spreading the declarations amongst Scalar.h and IPO.h
Fixes layering - Transforms/Utils shouldn't depend on including a Scalar
or IPO header, because Scalar and IPO depend on Utils.

llvm-svn: 328717
2018-03-28 17:44:36 +00:00
Adam Nemet e4e1de60aa Revert "StructurizeCFG: Test for branch divergence correctly"
This reverts commit r325881.

Breaks many bots

llvm-svn: 326037
2018-02-24 17:29:09 +00:00
Nicolai Haehnle 43c1115cd4 StructurizeCFG: Test for branch divergence correctly
Summary:
This fixes cases like the new test @nonuniform. In that test, %cc itself
is a uniform value; however, when reading it after the end of the loop in
basic block %if, its value is effectively non-uniform.

This problem was encountered in
https://bugs.freedesktop.org/show_bug.cgi?id=103743; however, this change
in itself is not sufficient to fix that bug, as there is another issue
in the AMDGPU backend.

Change-Id: I32bbffece4a32f686fab54964dae1a5dd72949d4

Reviewers: arsenm, rampitec, jlebar

Subscribers: wdng, tpr, llvm-commits

Differential Revision: https://reviews.llvm.org/D40546

llvm-svn: 325881
2018-02-23 10:45:46 +00:00
Nicolai Haehnle 4afb64e4c6 Revert r321751, "StructurizeCFG: Fix broken backedge detection"
It causes regressions in various OpenGL test suites.

Keep the test cases introduced by r321751 as XFAIL, and add a test case
for the regression.

Change-Id: I90b4cc354f68cebe5fcef1f2422dc8fe1c6d3514
Bugzilla: https://bugs.llvm.org/show_bug.cgi?id=36015
llvm-svn: 323355
2018-01-24 18:02:05 +00:00
Matt Arsenault 8070882b4e StructurizeCFG: Fix broken backedge detection
The work order was changed in r228186 from SCC order
to RPO with an arbitrary sorting function. The sorting
function attempted to move inner loop nodes earlier. This
was was apparently relying on an assumption that every block
in a given loop / the same loop depth would be seen before
visiting another loop. In the broken testcase, a block
outside of the loop was encountered before moving onto
another block in the same loop. The testcase would then
structurize such that one blocks unconditional successor
could never be reached.

Revert to plain RPO for the analysis phase. This fixes
detecting edges as backedges that aren't really.

The processing phase does use another visited set, and
I'm unclear on whether the order there is as important.
An arbitrary order doesn't work, and triggers some infinite
loops. The reversed RPO list seems to work and is closer
to the order that was used before, minus the arbitary
custom sorting.

A few of the changed tests now produce smaller code,
and a few are slightly worse looking.

llvm-svn: 321751
2018-01-03 18:45:37 +00:00
Matt Arsenault 8dcfa137f3 StructurizeCFG: Use phi iterator range
llvm-svn: 321568
2017-12-29 19:25:57 +00:00
Eugene Zelenko 99241d75c1 [Transforms] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).
llvm-svn: 316241
2017-10-20 21:47:29 +00:00
Hiroshi Inoue 713b5ba2de fix trivial typos; NFC
sucessor -> successor 

llvm-svn: 307488
2017-07-09 05:54:44 +00:00
Chandler Carruth 6bda14b313 Sort the remaining #include lines in include/... and lib/....
I did this a long time ago with a janky python script, but now
clang-format has built-in support for this. I fed clang-format every
line with a #include and let it re-sort things according to the precise
LLVM rules for include ordering baked into clang-format these days.

I've reverted a number of files where the results of sorting includes
isn't healthy. Either places where we have legacy code relying on
particular include ordering (where possible, I'll fix these separately)
or where we have particular formatting around #include lines that
I didn't want to disturb in this patch.

This patch is *entirely* mechanical. If you get merge conflicts or
anything, just ignore the changes in this patch and run clang-format
over your #include lines in the files.

Sorry for any noise here, but it is important to keep these things
stable. I was seeing an increasing number of patches with irrelevant
re-ordering of #include lines because clang-format was used. This patch
at least isolates that churn, makes it easy to skip when resolving
conflicts, and gets us to a clean baseline (again).

llvm-svn: 304787
2017-06-06 11:49:48 +00:00
Matt Arsenault 4474652c95 Revert "StructurizeCFG: Directly invert cmp instructions"
This reverts commit r300732. This breaks a few tests.
I think the problem is related to adding more uses of
the condition that don't yet exist at this point.

llvm-svn: 301242
2017-04-24 20:25:01 +00:00
Matt Arsenault d3406bc45c StructurizeCFG: Directly invert cmp instructions
The most common case for a branch condition is
a single use compare. Directly invert the branch
predicate rather than adding a lot of xor i1 true
which the DAG will have to fold later.

This produces nicer to read structurizer output.

This produces some random changes in codegen
due to the DAG swapping branch conditions itself,
and then does a poor job of dealing with those
inverts.

llvm-svn: 300732
2017-04-19 18:29:07 +00:00
Serge Pavlov 0668cd2c95 [StructurizeCfg] Update dominator info.
In some cases StructurizeCfg updates root node, but dominator info
remains unchanges, it causes crash when expensive checks are enabled.
To cope with this problem a new method was added to DominatorTreeBase
that allows adding new root nodes, it is called in StructurizeCfg to
put dominator tree in sync.

This change fixes PR27488.

Differential Revision: https://reviews.llvm.org/D28114

llvm-svn: 291530
2017-01-10 02:50:47 +00:00
Justin Lebar 96e2915574 [StructurizeCFG] Fix infinite loop in rebuildSSA.
Michel Dänzer reported that r288051, "[StructurizeCFG] Use range-based
for loops", introduced a bug into rebuildSSA, wherein we were iterating
over an instruction's use list while modifying it, without taking care
to do this correctly.

llvm-svn: 288200
2016-11-29 21:49:02 +00:00
Justin Lebar 3aec10ca7e [StructurizeCFG] Use range-based for loops.
Reviewers: arsenm

Subscribers: wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D27000

llvm-svn: 288051
2016-11-28 18:50:03 +00:00
Justin Lebar 62c20d8b3b [StructurizeCFG] Refactor NearestCommonDominator.
Summary:
As far as I can tell, doing our own computations in
NearestCommonDominator is a false optimization -- DomTree will build up
what appears to be exactly this data when it decides it's worthwhile.
Moreover, by building the cache ourselves, we cannot take advantage of
the cache that the domtree might have available.

In addition, I am not convinced of the correctness of the original code.
In particular, setting ResultIndex = 1 on the first addBlock instead of
setting it to 0 is quite fishy.  Similarly, it's not clear to me that
setting IndexMap[Node] = 0 for every node as we walk up the tree finding
a common parent is correct.  But rather than ponder over these
questions, I'd rather just make the code do the obviously-correct thing.

This patch also changes the NearestCommonDominator API a bit, improving
the names and getting rid of the boolean parameter in addBlock -- see
http://jlebar.com/2011/12/16/Boolean_parameters_to_API_functions_considered_harmful..html

Reviewers: arsenm

Subscribers: aemerson, wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D26998

llvm-svn: 288050
2016-11-28 18:49:59 +00:00
Justin Lebar 6c0f25aec6 [StructurizeCFG] Refactor OrderNodes.
Summary:
No need to copy the RPOT vector before using it.  Switch from std::map
to SmallDenseMap.  Get rid of an unused variable (TempVisited).  Get rid
of a typedef, RNVector, which is now used only once.

Differential Revision: https://reviews.llvm.org/D26997

llvm-svn: 287721
2016-11-22 23:14:11 +00:00
Justin Lebar 23aaf60277 [StructurizeCFG] Add whitespace in getAnalysisUsage.
Summary:
"addRequired" and "addPreserved" look very similar when squished up next
to each other -- without the newline this code looked to me like it was
addRequired'ing DominatorTreeWrapperPass twice.

Reviewers: arsenm

Subscribers: wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D26996

llvm-svn: 287720
2016-11-22 23:14:07 +00:00
Justin Lebar 820db74c1e [StructurizeCFG] Remove unnecessary "using" in class.
Reviewers: arsenm

Subscribers: wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D26995

llvm-svn: 287719
2016-11-22 23:13:49 +00:00
Justin Lebar 73c4baf3a3 [StructurizeCFG] Merge the two constructors into one.
Reviewers: arsenm

Subscribers: wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D26994

llvm-svn: 287718
2016-11-22 23:13:44 +00:00
Justin Lebar 1b60d70025 [StructurizeCFG] Use a for-each loop instead of iterators in runOnRegion.
Summary:

Reviewers: arsenm

Subscribers: wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D26993

llvm-svn: 287717
2016-11-22 23:13:37 +00:00
Justin Lebar c7445d5731 [StructurizeCFG] Make hasOnlyUniformBranches a non-member function.
Summary: Lets us get rid of one member variable too.

Reviewers: arsenm

Subscribers: wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D26992

llvm-svn: 287716
2016-11-22 23:13:33 +00:00
Simon Pilgrim 7d18a70dac Fix spelling mistakes in Transforms comments. NFC.
Identified by Pedro Giffuni in PR27636.

llvm-svn: 287488
2016-11-20 13:19:49 +00:00
Mehdi Amini 117296c0a0 Use StringRef in Pass/PassManager APIs (NFC)
llvm-svn: 283004
2016-10-01 02:56:57 +00:00
David Majnemer 0d955d0bf5 Use the range variant of find instead of unpacking begin/end
If the result of the find is only used to compare against end(), just
use is_contained instead.

No functionality change is intended.

llvm-svn: 278433
2016-08-11 22:21:41 +00:00
Matt Arsenault 93be6e8c0a StructurizeCFG: Fix inverting constantexpr conditions
llvm-svn: 275626
2016-07-15 22:13:16 +00:00
Benjamin Kramer 135f735af1 Apply clang-tidy's modernize-loop-convert to most of lib/Transforms.
Only minor manual fixes. No functionality change intended.

llvm-svn: 273808
2016-06-26 12:28:59 +00:00
David Majnemer d770877328 Switch more loops to be range-based
This makes the code a little more concise, no functional change is
intended.

llvm-svn: 273644
2016-06-24 04:05:21 +00:00
Benjamin Kramer 4dea8f542b Avoid duplicated map lookups. No functionality change intended.
llvm-svn: 273030
2016-06-17 18:59:41 +00:00
Nicolai Haehnle 05b127da06 [StructurizeCFG] Annotate branches that were treated as uniform
Summary:
This fully solves the problem where the StructurizeCFG pass does not
consider the same branches as uniform as the SIAnnotateControlFlow pass.
The patch in D19013 helps with this problem, but is not sufficient
(and, interestingly, causes a "regression" with one of the existing
test cases).

No tests included here, because tests in D19013 already cover this.

Reviewers: arsenm, tstellarAMD

Subscribers: arsenm, llvm-commits

Differential Revision: http://reviews.llvm.org/D19018

llvm-svn: 266346
2016-04-14 17:42:35 +00:00
Tom Stellard 6fa4e290d7 StructurizeCFG: Initialize SkipUniformRegions in the default constructor
This should fix some random bot failures caused by r260336.

llvm-svn: 260342
2016-02-10 01:10:09 +00:00
Tom Stellard 755a4e6b57 StructurizeCFG: Add an option for skipping regions with only uniform branches
Summary:
Tests for this will be added once the AMDGPU backend enables this
option.

Reviewers: arsenm

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D16602

llvm-svn: 260336
2016-02-10 00:39:37 +00:00
Duncan P. N. Exon Smith be4d8cba1c Scalar: Remove remaining ilist iterator implicit conversions
Remove remaining `ilist_iterator` implicit conversions from
LLVMScalarOpts.

This change exposed some scary behaviour in
lib/Transforms/Scalar/SCCP.cpp around line 1770.  This patch changes a
call from `Function::begin()` to `&Function::front()`, since the return
was immediately being passed into another function that takes a
`Function*`.  `Function::front()` started to assert, since the function
was empty.  Note that `Function::end()` does not point at a legal
`Function*` -- it points at an `ilist_half_node` -- so the other
function was getting garbage before.  (I added the missing check for
`Function::isDeclaration()`.)

Otherwise, no functionality change intended.

llvm-svn: 250211
2015-10-13 19:26:58 +00:00
Pete Cooper ebcd748927 Convert a bunch of loops to foreach. NFC.
After r244074, we now have a successors() method to iterate over
all the successors of a TerminatorInst.  This commit changes a bunch
of eligible loops to use it.

llvm-svn: 244260
2015-08-06 20:22:46 +00:00
Richard Trieu 6b1aa5f5e1 Change range-based for-loops to be -Wrange-loop-analysis clean.
No functionality change.

llvm-svn: 234963
2015-04-15 01:21:15 +00:00
Benjamin Kramer 799003bf8c Re-sort includes with sort-includes.py and insert raw_ostream.h where it's used.
llvm-svn: 232998
2015-03-23 19:32:43 +00:00
Tom Stellard 080209d573 StructurizeCFG: Remove obsolete fix for loop backedge detection
This is no longer needed now that we are using a reverse post-order
traversal.

llvm-svn: 228187
2015-02-04 20:49:47 +00:00
Tom Stellard 071ec90b68 StructurizeCFG: Use a reverse post-order traversal
We were previously doing a post-order traversal and operating on the
list in reverse, however this would occasionaly cause backedges for
loops to be visited before some of the other blocks in the loop.

We know use a reverse post-order traversal, which avoids this issue.

The reverse post-order traversal is not completely ideal, so we need
to manually fixup the list to ensure that inner loop backedges are
visited before outer loop backedges.

llvm-svn: 228186
2015-02-04 20:49:44 +00:00
Chandler Carruth 4f8f307c77 [PM] Split the LoopInfo object apart from the legacy pass, creating
a LoopInfoWrapperPass to wire the object up to the legacy pass manager.

This switches all the clients of LoopInfo over and paves the way to port
LoopInfo to the new pass manager. No functionality change is intended
with this iteration.

llvm-svn: 226373
2015-01-17 14:16:18 +00:00
Tom Stellard 1f0dded057 StructurizeCFG: Use LoopInfo analysis for better loop detection
We were assuming that each back-edge in a region represented a unique
loop, which is not always the case.  We need to use LoopInfo to
correctly determine which back-edges are loops.

llvm-svn: 223199
2014-12-03 04:28:32 +00:00
Duncan P. N. Exon Smith 6c99015fe2 Revert "[C++11] Add predecessors(BasicBlock *) / successors(BasicBlock *) iterator ranges."
This reverts commit r213474 (and r213475), which causes a miscompile on
a stage2 LTO build.  I'll reply on the list in a moment.

llvm-svn: 213562
2014-07-21 17:06:51 +00:00
Manuel Jacob d11beffef4 [C++11] Add predecessors(BasicBlock *) / successors(BasicBlock *) iterator ranges.
Summary: This patch introduces two new iterator ranges and updates existing code to use it.  No functional change intended.

Test Plan: All tests (make check-all) still pass.

Reviewers: dblaikie

Reviewed By: dblaikie

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D4481

llvm-svn: 213474
2014-07-20 09:10:11 +00:00
Matt Arsenault 1b8d83796d Templatify RegionInfo so it works on MachineBasicBlocks
llvm-svn: 213456
2014-07-19 18:29:29 +00:00
Matt Arsenault 04b67ceeeb Use range for
llvm-svn: 209147
2014-05-19 17:52:48 +00:00
Duncan P. N. Exon Smith d2b2facb07 SCC: Change clients to use const, NFC
It's fishy to be changing the `std::vector<>` owned by the iterator, and
no one actual does it, so I'm going to remove the ability in a
subsequent commit.  First, update the users.

<rdar://problem/14292693>

llvm-svn: 207252
2014-04-25 18:24:50 +00:00
Craig Topper f40110f4d8 [C++] Use 'nullptr'. Transforms edition.
llvm-svn: 207196
2014-04-25 05:29:35 +00:00
Chandler Carruth 964daaaf19 [Modules] Fix potential ODR violations by sinking the DEBUG_TYPE
definition below all of the header #include lines, lib/Transforms/...
edition.

This one is tricky for two reasons. We again have a couple of passes
that define something else before the includes as well. I've sunk their
name macros with the DEBUG_TYPE.

Also, InstCombine contains headers that need DEBUG_TYPE, so now those
headers #define and #undef DEBUG_TYPE around their code, leaving them
well formed modular headers. Fixing these headers was a large motivation
for all of these changes, as "leaky" macros of this form are hard on the
modules implementation.

llvm-svn: 206844
2014-04-22 02:55:47 +00:00
Chandler Carruth cdf4788401 [C++11] Add range based accessors for the Use-Def chain of a Value.
This requires a number of steps.
1) Move value_use_iterator into the Value class as an implementation
   detail
2) Change it to actually be a *Use* iterator rather than a *User*
   iterator.
3) Add an adaptor which is a User iterator that always looks through the
   Use to the User.
4) Wrap these in Value::use_iterator and Value::user_iterator typedefs.
5) Add the range adaptors as Value::uses() and Value::users().
6) Update *all* of the callers to correctly distinguish between whether
   they wanted a use_iterator (and to explicitly dig out the User when
   needed), or a user_iterator which makes the Use itself totally
   opaque.

Because #6 requires churning essentially everything that walked the
Use-Def chains, I went ahead and added all of the range adaptors and
switched them to range-based loops where appropriate. Also because the
renaming requires at least churning every line of code, it didn't make
any sense to split these up into multiple commits -- all of which would
touch all of the same lies of code.

The result is still not quite optimal. The Value::use_iterator is a nice
regular iterator, but Value::user_iterator is an iterator over User*s
rather than over the User objects themselves. As a consequence, it fits
a bit awkwardly into the range-based world and it has the weird
extra-dereferencing 'operator->' that so many of our iterators have.
I think this could be fixed by providing something which transforms
a range of T&s into a range of T*s, but that *can* be separated into
another patch, and it isn't yet 100% clear whether this is the right
move.

However, this change gets us most of the benefit and cleans up
a substantial amount of code around Use and User. =]

llvm-svn: 203364
2014-03-09 03:16:01 +00:00