Commit Graph

53 Commits

Author SHA1 Message Date
Diego Novillo 7f8af8bf91 Add support for missed and analysis optimization remarks.
Summary:
This adds two new diagnostics: -pass-remarks-missed and
-pass-remarks-analysis. They take the same values as -pass-remarks but
are intended to be triggered in different contexts.

-pass-remarks-missed is used by LLVMContext::emitOptimizationRemarkMissed,
which passes call when they tried to apply a transformation but
couldn't.

-pass-remarks-analysis is used by LLVMContext::emitOptimizationRemarkAnalysis,
which passes call when they want to inform the user about analysis
results.

The patch also:

1- Adds support in the inliner for the two new remarks and a
   test case.

2- Moves emitOptimizationRemark* functions to the llvm namespace.

3- Adds an LLVMContext argument instead of making them member functions
   of LLVMContext.

Reviewers: qcolombet

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D3682

llvm-svn: 209442
2014-05-22 14:19:46 +00:00
Diego Novillo 34fc8a7c4c Add optimization remarks to the loop unroller and vectorizer.
Summary:
This calls emitOptimizationRemark from the loop unroller and vectorizer
at the point where they make a positive transformation. For the
vectorizer, it reports vectorization and interleave factors. For the
loop unroller, it reports all the different supported types of
unrolling.

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D3456

llvm-svn: 207528
2014-04-29 14:27:31 +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 d84f776e8a [LPM] Fix PR18616 where the shifts to the loop pass manager to extract
LCSSA from it caused a crasher with the LoopUnroll pass.

This crasher is really nasty. We destroy LCSSA form in a suprising way.
When unrolling a loop into an outer loop, we not only need to restore
LCSSA form for the outer loop, but for all children of the outer loop.
This is somewhat obvious in retrospect, but hey!

While this seems pretty heavy-handed, it's not that bad. Fundamentally,
we only do this when we unroll a loop, which is already a heavyweight
operation. We're unrolling all of these hypothetical inner loops as
well, so their size and complexity is already on the critical path. This
is just adding another pass over them to re-canonicalize.

I have a test case from PR18616 that is great for reproducing this, but
pretty useless to check in as it relies on many 10s of nested empty
loops that get unrolled and deleted in just the right order. =/ What's
worse is that investigating this has exposed another source of failure
that is likely to be even harder to test. I'll try to come up with test
cases for these fixes, but I want to get the fixes into the tree first
as they're causing crashes in the wild.

llvm-svn: 200273
2014-01-28 01:25:38 +00:00
Chandler Carruth aa7fa5e4b2 [LPM] Make LoopSimplify no longer a LoopPass and instead both a utility
function and a FunctionPass.

This has many benefits. The motivating use case was to be able to
compute function analysis passes *after* running LoopSimplify (to avoid
invalidating them) and then to run other passes which require
LoopSimplify. Specifically passes like unrolling and vectorization are
critical to wire up to BranchProbabilityInfo and BlockFrequencyInfo so
that they can be profile aware. For the LoopVectorize pass the only
things in the way are LoopSimplify and LCSSA. This fixes LoopSimplify
and LCSSA is next on my list.

There are also a bunch of other benefits of doing this:
- It is now very feasible to make more passes *preserve* LoopSimplify
  because they can simply run it after changing a loop. Because
  subsequence passes can assume LoopSimplify is preserved we can reduce
  the runs of this pass to the times when we actually mutate a loop
  structure.
- The new pass manager should be able to more easily support loop passes
  factored in this way.
- We can at long, long last observe that LoopSimplify is preserved
  across SCEV. This *halves* the number of times we run LoopSimplify!!!

Now, getting here wasn't trivial. First off, the interfaces used by
LoopSimplify are all over the map regarding how analysis are updated. We
end up with weird "pass" parameters as a consequence. I'll try to clean
at least some of this up later -- I'll have to have it all clean for the
new pass manager.

Next up I discovered a really frustrating bug. LoopUnroll *claims* to
preserve LoopSimplify. That's actually a lie. But the way the
LoopPassManager ends up running the passes, it always ran LoopSimplify
on the unrolled-into loop, rectifying this oversight before any
verification could kick in and point out that in fact nothing was
preserved. So I've added code to the unroller to *actually* simplify the
surrounding loop when it succeeds at unrolling.

The only functional change in the test suite is that we now catch a case
that was previously missed because SCEV and other loop transforms see
their containing loops as simplified and thus don't miss some
opportunities. One test case has been converted to check that we catch
this case rather than checking that we miss it but at least don't get
the wrong answer.

Note that I have #if-ed out all of the verification logic in
LoopSimplify! This is a temporary workaround while extracting these bits
from the LoopPassManager. Currently, there is no way to have a pass in
the LoopPassManager which preserves LoopSimplify along with one which
does not. The LPM will try to verify on each loop in the nest that
LoopSimplify holds but the now-Function-pass cannot distinguish what
loop is being verified and so must try to verify all of them. The inner
most loop is clearly no longer simplified as there is a pass which
didn't even *attempt* to preserve it. =/ Once I get LCSSA out (and maybe
LoopVectorize and some other fixes) I'll be able to re-enable this check
and catch any places where we are still failing to preserve
LoopSimplify. If this causes problems I can back this out and try to
commit *all* of this at once, but so far this seems to work and allow
much more incremental progress.

llvm-svn: 199884
2014-01-23 11:23:19 +00:00
Chandler Carruth 73523021d0 [PM] Split DominatorTree into a concrete analysis result object which
can be used by both the new pass manager and the old.

This removes it from any of the virtual mess of the pass interfaces and
lets it derive cleanly from the DominatorTreeBase<> template. In turn,
tons of boilerplate interface can be nuked and it turns into a very
straightforward extension of the base DominatorTree interface.

The old analysis pass is now a simple wrapper. The names and style of
this split should match the split between CallGraph and
CallGraphWrapperPass. All of the users of DominatorTree have been
updated to match using many of the same tricks as with CallGraph. The
goal is that the common type remains the resulting DominatorTree rather
than the pass. This will make subsequent work toward the new pass
manager significantly easier.

Also in numerous places things became cleaner because I switched from
re-running the pass (!!! mid way through some other passes run!!!) to
directly recomputing the domtree.

llvm-svn: 199104
2014-01-13 13:07:17 +00:00
Chandler Carruth 5ad5f15cff [cleanup] Move the Dominators.h and Verifier.h headers into the IR
directory. These passes are already defined in the IR library, and it
doesn't make any sense to have the headers in Analysis.

Long term, I think there is going to be a much better way to divide
these matters. The dominators code should be fully separated into the
abstract graph algorithm and have that put in Support where it becomes
obvious that evn Clang's CFGBlock's can use it. Then the verifier can
manually construct dominance information from the Support-driven
interface while the Analysis library can provide a pass which both
caches, reconstructs, and supports a nice update API.

But those are very long term, and so I don't want to leave the really
confusing structure until that day arrives.

llvm-svn: 199082
2014-01-13 09:26:24 +00:00
Jakub Staszak 3ab283c157 Don't #include heavy Dominators.h file in LoopInfo.h. This change reduces
overall time of LLVM compilation by ~1%.

llvm-svn: 196667
2013-12-07 21:20:17 +00:00
NAKAMURA Takumi f9c8339a4e Utils/LoopUnroll.cpp: Tweak (StringRef)OldName to be valid until it is used, since r194601.
eraseFromParent() invalidates OldName.

llvm-svn: 194970
2013-11-17 18:05:34 +00:00
Jakub Staszak 86a7492f0d Use StringRef instead of std::string
llvm-svn: 194601
2013-11-13 20:09:11 +00:00
Benjamin Kramer 7d6052687e Replace some unnecessary vector copies with references.
llvm-svn: 190770
2013-09-15 22:04:42 +00:00
Chandler Carruth 9fb823bbd4 Move all of the header files which are involved in modelling the LLVM IR
into their new header subdirectory: include/llvm/IR. This matches the
directory structure of lib, and begins to correct a long standing point
of file layout clutter in LLVM.

There are still more header files to move here, but I wanted to handle
them in separate commits to make tracking what files make sense at each
layer easier.

The only really questionable files here are the target intrinsic
tablegen files. But that's a battle I'd rather not fight today.

I've updated both CMake and Makefile build systems (I think, and my
tests think, but I may have missed something).

I've also re-sorted the includes throughout the project. I'll be
committing updates to Clang, DragonEgg, and Polly momentarily.

llvm-svn: 171366
2013-01-02 11:36:10 +00:00
Chandler Carruth ed0881b2a6 Use the new script to sort the includes of every file under lib.
Sooooo many of these had incorrect or strange main module includes.
I have manually inspected all of these, and fixed the main module
include to be the nearest plausible thing I could find. If you own or
care about any of these source files, I encourage you to take some time
and check that these edits were sensible. I can't have broken anything
(I strictly added headers, and reordered them, never removed), but they
may not be the headers you'd really like to identify as containing the
API being implemented.

Many forward declarations and missing includes were added to a header
files to allow them to parse cleanly when included first. The main
module rule does in fact have its merits. =]

llvm-svn: 169131
2012-12-03 16:50:05 +00:00
Andrew Trick a6fb910fad LoopUnroll: always check for NULL LoopPassManager
llvm-svn: 158007
2012-06-05 17:51:05 +00:00
Andrew Trick d29cd732d4 Allow NULL LoopPassManager argument in UnrollLoop. PR12734.
llvm-svn: 156358
2012-05-08 02:52:09 +00:00
Andrew Trick 4442bfe559 Fix 12513: Loop unrolling breaks with indirect branches.
Take this opportunity to generalize the indirectbr bailout logic for
loop transformations. CFG transformations will never get indirectbr
right, and there's no point trying.

llvm-svn: 154386
2012-04-10 05:14:42 +00:00
Andrew Trick ca3417e932 Avoid a confusing assert for silly options: -unroll-runtime -unroll-count=1.
No need for an explicit test case for an unsupported combination of options.

llvm-svn: 146721
2011-12-16 02:03:48 +00:00
Andrew Trick d04d152998 Add -unroll-runtime for unrolling loops with run-time trip counts.
Patch by Brendon Cahoon!

This extends the existing LoopUnroll and LoopUnrollPass. Brendon
measured no regressions in the llvm test suite with -unroll-runtime
enabled. This implementation works by using the existing loop
unrolling code to unroll the loop by a power-of-two (default 8). It
generates an if-then-else sequence of code prior to the loop to
execute the extra iterations before entering the unrolled loop.

llvm-svn: 146245
2011-12-09 06:19:40 +00:00
Andrew Trick 6dbb060778 Comments. Thanks for the spell check Nick!
Also, my apologies for spoiling the autocomplete on SimplifyInstructions.cpp. I couldn't think of a better filename.

llvm-svn: 137229
2011-08-10 18:07:05 +00:00
Andrew Trick 4d0040baf8 Invoke SimplifyIndVar when we partially unroll a loop. Fixes PR10534.
llvm-svn: 137203
2011-08-10 04:29:49 +00:00
Andrew Trick 78b40c3f3a Cleanup. Added LoopBlocksDFS::perform for simple clients.
llvm-svn: 137195
2011-08-10 01:59:05 +00:00
Andrew Trick b72bbe2a92 Fix the LoopUnroller to handle nontrivial loops and partial unrolling.
These are not individual bug fixes. I had to rewrite a good chunk of
the unroller to make it sane. I think it was getting lucky on trivial
completely unrolled loops with no early exits. I included some fairly
simple unit tests for partial unrolling. I didn't do much stress
testing, so it may not be perfect, but should be usable now.

llvm-svn: 137190
2011-08-10 00:28:10 +00:00
Andrew Trick 5e0ee1c7f2 LoopUnroll looks like it has some stale code. Remove it to prove my sanity and avoid further confusion.
llvm-svn: 137106
2011-08-09 03:11:29 +00:00
Andrew Trick bf69d03382 SCEV: Use AssertingVH to catch dangling BasicBlock* when passes forget
to notify SCEV of a change. Add forgetLoop in a couple of those places.

llvm-svn: 136797
2011-08-03 18:32:11 +00:00
Andrew Trick 990f771a9a Add clarifying comments for the new arguments to UnrollLoop.
llvm-svn: 135988
2011-07-25 22:17:47 +00:00
Andrew Trick 1cabe54fab Move trip count discovery outside of the generic LoopUnroll helper. This
removes its dependence on canonical induction variables.

llvm-svn: 135829
2011-07-23 00:33:05 +00:00
Andrew Trick 279e7a6c83 whitespace
llvm-svn: 135828
2011-07-23 00:29:16 +00:00
Jay Foad 61ea0e4692 Reinstate r133513 (reverted in r133700) with an additional fix for a
-Wshorten-64-to-32 warning in Instructions.h.

llvm-svn: 133708
2011-06-23 09:09:15 +00:00
Eric Christopher 96513120b7 Revert r133513:
"Reinstate r133435 and r133449 (reverted in r133499) now that the clang
self-hosted build failure has been fixed (r133512)."

Due to some additional warnings.

llvm-svn: 133700
2011-06-23 06:24:52 +00:00
Benjamin Kramer ccbb77f239 Remove unused variables.
llvm-svn: 133514
2011-06-21 14:58:30 +00:00
Jay Foad a97a2c998e Reinstate r133435 and r133449 (reverted in r133499) now that the clang
self-hosted build failure has been fixed (r133512).

llvm-svn: 133513
2011-06-21 10:33:19 +00:00
Chad Rosier 184f3b37e2 Revert r133435 and r133449 to appease buildbots.
llvm-svn: 133499
2011-06-21 02:09:03 +00:00
Jay Foad e03c05c35a Change how PHINodes store their operands.
Change PHINodes to store simple pointers to their incoming basic blocks,
instead of full-blown Uses.

Note that this loses an optimization in SplitCriticalEdge(), because we
can no longer walk the use list of a BasicBlock to find phi nodes. See
the comment I removed starting "However, the foreach loop is slow for
blocks with lots of predecessors".

Extend replaceAllUsesWith() on a BasicBlock to also update any phi
nodes in the block's successors. This mimics what would have happened
when PHINodes were proper Users of their incoming blocks. (Note that
this only works if OldBB->replaceAllUsesWith(NewBB) is called when
OldBB still has a terminator instruction, so it still has some
successors.)

llvm-svn: 133435
2011-06-20 14:38:01 +00:00
Chris Lattner 4a14fbc50c Don't unroll loops whose header block's address is taken.
This is part of a futile attempt to not "break" bizzaro
code like this:

 l1:
  printf("l1: %p\n", &&l1);
  ++x;

  if( x < 3 ) goto l1;


Previously we'd fold &&l1 to 1, which is fine per our semantics
but not helpful to the user.

llvm-svn: 125827
2011-02-18 04:25:21 +00:00
Chris Lattner dfcfcb49fa random cleanups
llvm-svn: 123221
2011-01-11 08:00:40 +00:00
Jay Foad 89afb43b1e Remove all uses of the "ugly" method BranchInst::setUnconditionalDest().
llvm-svn: 123025
2011-01-07 20:25:56 +00:00
Duncan Sands 433c1679cf Replace calls to ConstantFoldInstruction with calls to SimplifyInstruction
in two places that are really interested in simplified instructions, not
constants.

llvm-svn: 120044
2010-11-23 20:26:33 +00:00
Rafael Espindola 229e38f0fe Be more consistent in using ValueToValueMapTy.
llvm-svn: 116387
2010-10-13 01:36:30 +00:00
Dan Gohman a7908ae369 Preserve ScalarEvolution in the loop unroller.
llvm-svn: 109412
2010-07-26 18:02:06 +00:00
Devang Patel 0dc3c2d37e Use ValueMap instead of DenseMap.
The ValueMapper used by various cloning utility maps MDNodes also.

llvm-svn: 106706
2010-06-24 00:33:28 +00:00
Devang Patel b8f11de105 Cosmetic change.
Do not use "ValueMap" as a name for a local variable or an argument.

llvm-svn: 106698
2010-06-23 23:55:51 +00:00
Devang Patel 2176643241 Rename ValueMapTy as ValueToValueMapTy to clearly indicate that this has no replationship with ADT/ValueMap.
llvm-svn: 101950
2010-04-20 22:24:18 +00:00
Dan Gohman 2734ebd37f Add a DominatorTree argument to isLCSSA so that it doesn't have to
compute a set of reachable blocks for itself each time it is called, which
is fairly frequently.

llvm-svn: 98179
2010-03-10 19:38:49 +00:00
Benjamin Kramer 1266d46d32 Don't bother with sprintf, just pass the Twine through.
llvm-svn: 94684
2010-01-27 19:58:47 +00:00
David Greene 627f40a9f2 Change errs() to dbgs().
llvm-svn: 92600
2010-01-05 01:26:41 +00:00
Dan Gohman 18fa5686f6 Add Loop contains utility methods for testing whether a loop
contains another loop, or an instruction. The loop form is
substantially more efficient on large loops than the typical
code it replaces.

llvm-svn: 91654
2009-12-18 01:24:09 +00:00
Chris Lattner 46b5c642b9 remove a bunch of extraneous LLVMContext arguments
from various APIs, addressing PR5325.

llvm-svn: 86231
2009-11-06 04:27:31 +00:00
Dan Gohman 415c64ea3f Teach LoopUnroll how to bail if LoopSimplify can't give it what it needs.
llvm-svn: 86164
2009-11-05 19:44:06 +00:00
Dan Gohman 2d02ff8cbb Revert r85667. LoopUnroll currently can't call utility functions which
auto-update the DominatorTree because it doesn't keep the DominatorTree
current while it works.

llvm-svn: 85670
2009-10-31 17:33:01 +00:00