Commit Graph

611 Commits

Author SHA1 Message Date
Quentin Colombet c88baa5c10 [LSR] Canonicalize reg1 + ... + regN into reg1 + ... + 1*regN.
This commit introduces a canonical representation for the formulae.
Basically, as soon as a formula has more that one base register, the scaled
register field is used for one of them. The register put into the scaled
register is preferably a loop variant.
The commit refactors how the formulae are built in order to produce such
representation.
This yields a more accurate, but still perfectible, cost model.

<rdar://problem/16731508>

llvm-svn: 209230
2014-05-20 19:25:04 +00:00
Adam Nemet deab6f945c Reapply r207271 without the testcase
PR19608 was filed to find a suitable testcase.

llvm-svn: 207569
2014-04-29 18:25:28 +00:00
Chandler Carruth c71b2c3c7f Revert r207271 for now. This commit introduced a test case that ran
clang directly from the LLVM test suite! That doesn't work. I've
followed up on the review thread to try and get a viable solution sorted
out, but trying to get the tree clean here.

llvm-svn: 207462
2014-04-28 23:07:49 +00:00
Adam Nemet 03d91c51e4 [LoopStrengthReduce] Don't trim formula that uses a subset of required registers
Consider this use from the new testcase:

  LSR Use: Kind=ICmpZero, Offsets={0}, widest fixup type: i32
    reg({1000,+,-1}<nw><%for.body>)
    -3003 + reg({3,+,3}<nw><%for.body>)
    -1001 + reg({1,+,1}<nuw><nsw><%for.body>)
    -1000 + reg({0,+,1}<nw><%for.body>)
    -3000 + reg({0,+,3}<nuw><%for.body>)
    reg({-1000,+,1}<nw><%for.body>)
    reg({-3000,+,3}<nsw><%for.body>)

This is the last use we consider for a solution in SolveRecurse, so CurRegs is
a large set.  (CurRegs is the set of registers that are needed by the
previously visited uses in the in-progress solution.)

ReqRegs is {
  {3,+,3}<nw><%for.body>,
  {1,+,1}<nuw><nsw><%for.body>
}

This is the intersection of the regs used by any of the formulas for the
current use and CurRegs.

Now, the code requires a formula to contain *all* these regs (the comment is
simply wrong), otherwise the formula is immediately disqualified.  Obviously,
no formula for this use contains two regs so they will all get disqualified.

The fix modifies the check to allow the formula in this case.  The idea is
that neither of these formulae is introducing any new registers which is the
point of this early pruning as far as I understand.

In terms of set arithmetic, we now allow formulas whose used regs are a subset
of the required regs not just the other way around.

There are few more loops in the test-suite that are now successfully LSRed.  I
have benchmarked those and found very minimal change.

Fixes <rdar://problem/13965777>

llvm-svn: 207271
2014-04-25 21:02:21 +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
Arnaud A. de Grandmaison 75c9e6dedf Remove some dead assignements found by scan-build
llvm-svn: 204013
2014-03-15 22:13:15 +00:00
Benjamin Kramer 62fb0cfb97 LSR: Compress a pair (and get rid of the DenseMapInfo for it).
Also convert a horrible hash function to use our hashing infrastructure.
No functionality change.

llvm-svn: 204008
2014-03-15 17:17:48 +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
Craig Topper 3e4c697ca1 [C++11] Add 'override' keyword to virtual methods that override their base class.
llvm-svn: 202953
2014-03-05 09:10:37 +00:00
Chandler Carruth 4220e9c154 [Modules] Move ValueHandle into the IR library where Value itself lives.
Move the test for this class into the IR unittests as well.

This uncovers that ValueMap too is in the IR library. Ironically, the
unittest for ValueMap is useless in the Support library (honestly, so
was the ValueHandle test) and so it already lives in the IR unittests.
Mmmm, tasty layering.

llvm-svn: 202821
2014-03-04 11:17:44 +00:00
Benjamin Kramer b2f034b85e [C++11] Use std::tie to simplify compare operators.
No functionality change.

llvm-svn: 202751
2014-03-03 19:58:30 +00:00
Benjamin Kramer b6d0bd48bd [C++11] Replace llvm::next and llvm::prior with std::next and std::prev.
Remove the old functions.

llvm-svn: 202636
2014-03-02 12:27:27 +00:00
Andrew Trick 429e9edd08 Fix PR18165: LSR must avoid scaling factors that exceed the limit on truncated use.
Patch by Michael Zolotukhin!

llvm-svn: 202273
2014-02-26 16:31:56 +00:00
Paul Robinson af4e64d095 Disable most IR-level transform passes on functions marked 'optnone'.
Ideally only those transform passes that run at -O0 remain enabled,
in reality we get as close as we reasonably can.
Passes are responsible for disabling themselves, it's not the job of
the pass manager to do it for them.

llvm-svn: 200892
2014-02-06 00:07:05 +00:00
Tim Northover bc6659c4e9 Loop strength reduce: fix function name.
llvm-svn: 199801
2014-01-22 13:27:00 +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
Chandler Carruth d48cdbf0c3 Put the functionality for printing a value to a raw_ostream as an
operand into the Value interface just like the core print method is.
That gives a more conistent organization to the IR printing interfaces
-- they are all attached to the IR objects themselves. Also, update all
the users.

This removes the 'Writer.h' header which contained only a single function
declaration.

llvm-svn: 198836
2014-01-09 02:29:41 +00:00
Chandler Carruth 9aca918df9 Move the LLVM IR asm writer header files into the IR directory, as they
are part of the core IR library in order to support dumping and other
basic functionality.

Rename the 'Assembly' include directory to 'AsmParser' to match the
library name and the only functionality left their -- printing has been
in the core IR library for quite some time.

Update all of the #includes to match.

All of this started because I wanted to have the layering in good shape
before I started adding support for printing LLVM IR using the new pass
infrastructure, and commandline support for the new pass infrastructure.

llvm-svn: 198688
2014-01-07 12:34:26 +00:00
Chandler Carruth 8a8cd2bab9 Re-sort all of the includes with ./utils/sort_includes.py so that
subsequent changes are easier to review. About to fix some layering
issues, and wanted to separate out the necessary churn.

Also comment and sink the include of "Windows.h" in three .inc files to
match the usage in Memory.inc.

llvm-svn: 198685
2014-01-07 11:48:04 +00:00
Andrew Trick 57243da70f Fix SCEVExpander: don't try to expand quadratic recurrences outside a loop.
Partial fix for PR17459: wrong code at -O3 on x86_64-linux-gnu
(affecting trunk and 3.3)

When SCEV expands a recurrence outside of a loop it attempts to scale
by the stride of the recurrence. Chained recurrences don't work that
way. We could compute binomial coefficients, but would hve to
guarantee that the chained AddRec's are in a perfectly reduced form.

llvm-svn: 193438
2013-10-25 21:35:56 +00:00
Quentin Colombet 145eb97d3a LSR: Fix the parameters used to compute the scaling factor cost.
Prior to this change, the considered addressing modes may be invalid since the
maximum and minimum offsets were not taking into account.
This was causing an assertion failure.

The added test case exercices that behavior.

<rdar://problem/14199725> Assertion failed: (CurScaleCost >= 0 && "Legal
addressing mode has an illegal cost!")

llvm-svn: 184341
2013-06-19 19:59:41 +00:00
Jakub Staszak 4898e62ac0 Use 0 instead of NULL.
llvm-svn: 184044
2013-06-15 12:20:44 +00:00
Quentin Colombet bf490d4a32 Loop Strength Reduce: Scaling factor cost.
Account for the cost of scaling factor in Loop Strength Reduce when rating the
formulae. This uses a target hook.

The default implementation of the hook is: if the addressing mode is legal, the
scaling factor is free.

<rdar://problem/13806271>

llvm-svn: 183045
2013-05-31 21:29:03 +00:00
Quentin Colombet 8aa7abe2ae Modify how the formulae are rated in Loop Strength Reduce.
Namely, check if the target allows to fold more that one register in the
addressing mode and if yes, adjust the cost accordingly.

Prior to this commit, reg1 + scale * reg2 accesses were artificially preferred
to reg1 + reg2 accesses. Indeed, the cost model wrongly assumed that reg1 + reg2
needs a temporary register for the computation, whereas it was correctly
estimated for reg1 + scale * reg2.

<rdar://problem/13973908>

llvm-svn: 183021
2013-05-31 17:20:29 +00:00
Michael J. Spencer df1ecbd734 Replace Count{Leading,Trailing}Zeros_{32,64} with count{Leading,Trailing}Zeros.
llvm-svn: 182680
2013-05-24 22:23:49 +00:00
Jakub Staszak f6df1e3def Use dyn_cast instead of isa && cast.
No functionality change.

llvm-svn: 177836
2013-03-24 09:25:47 +00:00
Andrew Trick f3a2544dba Revert "Cleanup some SCEV logic a bit."
This reverts commit 82cd8f7382322bee7a71cdc31f7a923c44d37d32.

Just add a comment instead!

llvm-svn: 177377
2013-03-19 05:10:27 +00:00
Andrew Trick de78866594 Cleanup some SCEV logic a bit.
Make the code more obvious to scan-build and humans.

llvm-svn: 177375
2013-03-19 04:14:59 +00:00
Andrew Trick a1c01ba8c7 Tighten up an internal LSR API that should check for NULL.
No test case, but should fix a scan_build warning.

llvm-svn: 177374
2013-03-19 04:14:57 +00:00
Jakub Staszak 11bd83551c Reduce indents in LSRInstance::NarrowSearchSpaceByCollapsingUnrolledCode method.
No functionality change.

llvm-svn: 175364
2013-02-16 16:08:15 +00:00
Andrew Trick bc7059032b LSR IVChain improvement.
Handle chains in which the same offset is used for both loads and
stores to the same array.

Fixes rdar://11410078.

llvm-svn: 174789
2013-02-09 01:11:01 +00:00
Jakub Staszak f23980aba5 Remove #includes from the commonly used LoopInfo.h.
llvm-svn: 174786
2013-02-09 01:04:28 +00:00
Preston Gurd 25c3b6acc0 This patch aims to improve compile time performance by increasing
the SCEV vector size in LoopStrengthReduce. It is observed that
the BaseRegs vector size is 4 in most cases,
and elements are frequently copied when it is initialized as
SmallVector<const SCEV *, 2> BaseRegs.
Our benchmark results show that the compilation time performance
improved by ~0.5%.

Patch by Wan Xiaofei.

llvm-svn: 174219
2013-02-01 20:41:27 +00:00
Chandler Carruth 7e31c8f0ae Fix an editor goof in r171738 that Bill spotted. He may even have a test
case, but looking at the diff this was an obviously unintended change.

Thanks for the careful review Bill! =]

llvm-svn: 172336
2013-01-12 23:46:04 +00:00
Chandler Carruth 6e479322aa Remove LSR's use of the random AddrMode struct. These variables were
already in a class, just inline the four of them. I suspect that this
class could be simplified some to not always keep distinct variables for
these things, but it wasn't clear to me how given the usage so I opted
for a trivial and mechanical translation.

This removes one of the two remaining users of a header in include/llvm
which does nothing more than define a 4 member struct.

llvm-svn: 171738
2013-01-07 15:04:40 +00:00
Chandler Carruth 26c59fa870 Switch the SCEV expander and LoopStrengthReduce to use
TargetTransformInfo rather than TargetLowering, removing one of the
primary instances of the layering violation of Transforms depending
directly on Target.

This is a really big deal because LSR used to be a "special" pass that
could only be tested fully using llc and by looking at the full output
of it. It also couldn't run with any other loop passes because it had to
be created by the backend. No longer is this true. LSR is now just
a normal pass and we should probably lift the creation of LSR out of
lib/CodeGen/Passes.cpp and into the PassManagerBuilder. =] I've not done
this, or updated all of the tests to use opt and a triple, because
I suspect someone more familiar with LSR would do a better job. This
change should be essentially without functional impact for normal
compilations, and only change behvaior of targetless compilations.

The conversion required changing all of the LSR code to refer to the TTI
interfaces, which fortunately are very similar to TargetLowering's
interfaces. However, it also allowed us to *always* expect to have some
implementation around. I've pushed that simplification through the pass,
and leveraged it to simplify code somewhat. It required some test
updates for one of two things: either we used to skip some checks
altogether but now we get the default "no" answer for them, or we used
to have no information about the target and now we do have some.

I've also started the process of removing AddrMode, as the TTI interface
doesn't use it any longer. In some cases this simplifies code, and in
others it adds some complexity, but I think it's not a bad tradeoff even
there. Subsequent patches will try to clean this up even further and use
other (more appropriate) abstractions.

Yet again, almost all of the formatting changes brought to you by
clang-format. =]

llvm-svn: 171735
2013-01-07 14:41:08 +00:00
Andrew Trick f950ce8e38 Fix a crash in LSR replaceCongruentIVs.
Indirect branch in the preheader crashes replaceCongruentIVs.
Fixes rdar://12910141.

llvm-svn: 171653
2013-01-06 05:59:39 +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
Nadav Rotem 4dc976fbcb revert r166264 because the LTO build is still failing
llvm-svn: 166340
2012-10-19 21:28:43 +00:00
Nadav Rotem 4985ddc5e0 recommit the patch that makes LSR and LowerInvoke use the TargetTransform interface.
llvm-svn: 166264
2012-10-19 04:27:49 +00:00
Bob Wilson d6d9ccca38 Temporarily revert the TargetTransform changes.
The TargetTransform changes are breaking LTO bootstraps of clang.  I am
working with Nadav to figure out the problem, but I am reverting it for now
to get our buildbots working.

This reverts svn commits: 165665 165669 165670 165786 165787 165997
and I have also reverted clang svn 165741

llvm-svn: 166168
2012-10-18 05:43:52 +00:00
Nadav Rotem e10328737d Add a new interface to allow IR-level passes to access codegen-specific information.
llvm-svn: 165665
2012-10-10 22:04:55 +00:00
Nadav Rotem 35315fea70 Refactor the AddrMode class out of TLI to its own header file.
This class is used by LSR and a number of places in the codegen.
This is the first step in de-coupling LSR from TLI, and creating
a new interface in between them.

llvm-svn: 165455
2012-10-08 23:06:34 +00:00
Andrew Trick 402edbbe39 LSR critical edge splitting fix for PR13756.
llvm-svn: 164147
2012-09-18 17:51:33 +00:00
Manman Ren 49d684e1e2 Release build: guard dump functions with
"#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)"

No functional change. Update r163344.

llvm-svn: 163679
2012-09-12 05:06:18 +00:00
Manman Ren c3366ccecb Release build: guard dump functions with "ifndef NDEBUG"
No functional change.

llvm-svn: 163344
2012-09-06 19:55:56 +00:00
Richard Smith ad9c8e839e Don't bind a reference to a dereferenced null pointer (for return value of WeakVH::operator*).
llvm-svn: 162309
2012-08-21 20:35:14 +00:00