Commit Graph

487 Commits

Author SHA1 Message Date
Johannes Doerfert 5d03f84cf5 Early exit for addInvariantLoads
llvm-svn: 267143
2016-04-22 11:38:44 +00:00
Johannes Doerfert 6296d95420 Bail for complex alias checks
llvm-svn: 267142
2016-04-22 11:38:19 +00:00
Johannes Doerfert 171b92f1e1 Relate domains to statements during construction [NFC]
Instead of the Scop::getPwAff() function we now use the ScopStmt::getPwAff()
  function during the statements domain construction.

llvm-svn: 266741
2016-04-19 14:53:13 +00:00
Johannes Doerfert ff68f46458 Add user assumptions after domain generation [NFC]
llvm-svn: 266740
2016-04-19 14:49:42 +00:00
Johannes Doerfert 535de03571 Do not build domains for out of SCoP blocks [NFC]
llvm-svn: 266739
2016-04-19 14:49:05 +00:00
Johannes Doerfert fff283df7a Mark Scop::getDomainConditions as const [NFC]
llvm-svn: 266738
2016-04-19 14:48:22 +00:00
Johannes Doerfert fb72187fdd [FIX] Check the invalid context agains the context to rule out SCoPs
llvm-svn: 266096
2016-04-12 17:54:29 +00:00
Johannes Doerfert 2f70584ae6 Do not by default minimize remarks
We used checks to minimize the number of remarks we present to a user
  but these checks can become expensive, especially since all wrapping
  assumptions are emitted separately. Because there is not benefit for a
  "headless" run we put these checks under a command line flag. Thus, if
  the flag is not given we will emit "non-effective" remarks, e.g.,
  duplicates and revert to the old behaviour if it is given. As this
  also changes the internal representation of some sets we set the flag
  by default for our unit tests.

llvm-svn: 266087
2016-04-12 16:09:44 +00:00
Johannes Doerfert 615e0b85f8 Record wrapping assumptions early
Utilizing the record option for assumptions we can simplify the wrapping
  assumption generation a lot. Additionally, we can now report locations
  together with wrapping assumptions, though they might not be accurate yet.

llvm-svn: 266069
2016-04-12 13:28:39 +00:00
Johannes Doerfert 3bf6e4129f Record assumptions first and add them later
There are three reasons why we want to record assumptions first before we
add them to the assumed/invalid context:

  1) If the SCoP is not profitable or otherwise invalid without the
     assumed/invalid context we do not have to compute it.
  2) Information about the context are gathered rather late in the SCoP
     construction (basically after we know all parameters), thus the user
     might see overly complicated assumptions to be taken while they would
     have been simplified later on.
  3) Currently we cannot take assumptions at any point but have to wait,
     e.g., for the domain generation to finish. This makes wrapping
     assumptions much more complicated as they need to be and it will
     have a similar effect on "signed-unsigned" assumptions later.

llvm-svn: 266068
2016-04-12 13:27:35 +00:00
Johannes Doerfert 97f0dcdea8 Introduce and use MemoryAccess::getPwAff() [NFC]
llvm-svn: 266066
2016-04-12 13:26:45 +00:00
Johannes Doerfert 127abd77a3 Do not assume switch modeling optimizes a SCoP
llvm-svn: 266065
2016-04-12 13:25:43 +00:00
Johannes Doerfert 7c01357cef Introduce an invalid context for each statement
Collect the error domain contexts (formerly in the ErrorDomainCtxMap)
  for each statement in the new InvalidContext member variable. While
  this commit is basically a [NFC] it is a first step to make hoisting
  sound by allowing a more fine grained record of invalid contexts,
  e.g., here on statement level.

llvm-svn: 266053
2016-04-12 09:57:34 +00:00
Michael Kruse 3b425ff232 Allow overflow of indices with constant dim-sizes.
Allow overflow of indices into the next higher dimension if it has
constant size. E.g.

    float A[32][2];
    ((float*)A)[5];

is effectively the same as

    A[2][1];

This can happen since r265379 as a side effect if ScopDetection
recognizes an access as affine, but ScopInfo rejects the GetElementPtr.

Differential Revision: http://reviews.llvm.org/D18878

llvm-svn: 265942
2016-04-11 14:34:08 +00:00
Michael Kruse 7071e8b355 Do not bind a non-const reference to a rvalue. NFC.
MSVC warns with:
warning C4239: nonstandard extension used: 'initializing': conversion from 'llvm::DebugLoc' to 'llvm::DebugLoc &'
note: A non-const reference may only be bound to an lvalue

Change the reference to a const reference.

llvm-svn: 265937
2016-04-11 13:24:29 +00:00
Johannes Doerfert 3c6a99b818 Add __isl_give annotations to return types [NFC]
llvm-svn: 265882
2016-04-09 21:55:23 +00:00
Johannes Doerfert 41725a1e7a [FIX] Do not crash on opaque (unsized) types.
llvm-svn: 265834
2016-04-08 19:20:03 +00:00
Michael Kruse 436c90619c [ScopInfo] Fix check for element size mismatch.
The way to get the elements size with getPrimitiveSizeInBits() is not
the same as used in other parts of Polly which should use
DataLayout::getTypeAllocSize(). Its use only queries the size of the
pointer and getPrimitiveSizeInBits returns 0 for types that require a
DataLayout object such as pointers.

Together with r265379, this should fix PR27195.

llvm-svn: 265795
2016-04-08 16:20:08 +00:00
Michael Kruse 1fdc2fff1a [ScopInfo] Rename variable to AccType. NFC.
This avoids a name clash with the type llvm::Type.

llvm-svn: 265788
2016-04-08 14:35:59 +00:00
Johannes Doerfert 41cda15940 [FIX] Allow to lookup domains for non-affine subregion blocks
llvm-svn: 265779
2016-04-08 10:32:26 +00:00
Johannes Doerfert 3ef78d6d38 [FIX] Adjust execution context of hoisted loads wrt. error domains
If we build the domains for error blocks and later remove them we lose
  the information that they are not executed. Thus, in the SCoP it looks
  like the control will always reach the statement S:

            for (i = 0 ... N)
                if (*valid == 0)
                  doSth(&ptr);
          S:    A[i] = *ptr;

  Consequently, we would have assumed "ptr" to be always accessed and
  preloaded it unconditionally. However, only if "*valid != 0" we would
  execute the optimized version of the SCoP. Nevertheless, we would have
  hoisted and accessed "ptr"regardless of "*valid". This changes the
  semantic of the program as the value of "*valid" can cause a change of
  "ptr" and control if it is executed or not.

  To fix this problem we adjust the execution context of hoisted loads
  wrt. error domains. To this end we introduce an ErrorDomainCtxMap that
  maps each basic block to the error context under which it might be
  executed. Thus, to the context under which it is executed but an error
  block would have been executed to. To fill this map one traversal of
  the blocks in the SCoP suffices. During this traversal we do also
  "remove" error statements and those that are only reachable via error
  statements. This was previously done by the removeErrorBlockDomains
  function which is therefor not needed anymore.

  This fixes bug PR26683 and thereby several SPEC miscompiles.

Differential Revision: http://reviews.llvm.org/D18822

llvm-svn: 265778
2016-04-08 10:30:09 +00:00
Johannes Doerfert 7b81103589 [FIX] Look through div & srem instructions in SCEVs
The findValues() function did not look through div & srem instructions
  that were part of the argument SCEV. However, in different other
  places we already look through it. This mismatch caused us to preload
  values in the wrong order.

llvm-svn: 265775
2016-04-08 10:25:58 +00:00
Johannes Doerfert a49c557f70 Remove dead code and comment [NFC]
llvm-svn: 265413
2016-04-05 16:18:53 +00:00
Johannes Doerfert 57c5f0b1c4 [FIX] Ensure SAI objects for exit PHIs
If all exiting blocks of a SCoP are error blocks and therefor not
  represented we will not generate accesses and consequently no SAI
  objects for exit PHIs. However, they are needed in the code generation
  to generate the merge PHIs between the original and optimized region.
  With this patch we enusre that the SAI objects for exit PHIs exist
  even if all exiting blocks turn out to be eror blocks.

  This fixes the crash reported in PR27207.

llvm-svn: 265393
2016-04-05 13:44:21 +00:00
Tobias Grosser 535afd808d ScopInfo: Check for possibly nested GEP in fixed-size delin
We currently only consider the first GEP when delinearizing access functions,
which makes us loose information about additional index expression offsets,
which results in our SCoP model to be incorrect. With this patch we now
compare the base pointers used to ensure we do not miss any additional offsets.
This fixes llvm.org/PR27195.

We may consider supporting nested GEP in our delinearization heuristics in
the future.

llvm-svn: 265379
2016-04-05 06:23:45 +00:00
Johannes Doerfert 1519491eaf Do not allow to complex branch conditions
Even before we build the domain the branch condition can become very
  complex, especially if we have to build the complement of a lot of
  equality constraints. With this patch we bail if the branch condition
  has a lot of basic sets and parameters.

  After this patch we now successfully compile
    External/SPEC/CINT2000/186_crafty/186_crafty
  with "-polly-process-unprofitable -polly-position=before-vectorizer".

llvm-svn: 265286
2016-04-04 07:59:41 +00:00
Johannes Doerfert 642594ae87 Exploit graph properties during domain generation
As a CFG is often structured we can simplify the steps performed during
  domain generation. When we push domain information we can utilize the
  information from a block A to build the domain of a block B, if A dominates B
  and there is no loop backede on a path from A to B. When we pull domain
  information we can use information from a block A to build the domain of a
  block B if B post-dominates A. This patch implements both ideas and thereby
  simplifies domains that were not simplified by isl. For the FINAL basic block
  in test/ScopInfo/complex-successor-structure-3.ll we used to build a universe
  set with 81 basic sets. Now it actually is represented as universe set.

  While the initial idea to utilize the graph structure depended on the
  dominator and post-dominator tree we can use the available region
  information as a coarse grained replacement. To this end we push the
  region entry domain to the region exit and pull it from the region
  entry for the region exit if applicable.

  With this patch we now successfully compile
    External/SPEC/CINT2006/400_perlbench/400_perlbench
  and
    SingleSource/Benchmarks/Adobe-C++/loop_unroll.

Differential Revision: http://reviews.llvm.org/D18450

llvm-svn: 265285
2016-04-04 07:57:39 +00:00
Johannes Doerfert a07f0ac73f Factor out "adjustDomainDimensions" function [NFC]
llvm-svn: 265284
2016-04-04 07:50:40 +00:00
Johannes Doerfert d5edbd61a1 [FIX] Do not create a SCoP in the presence of infinite loops
If a loop has no exiting blocks the region covering we use during
  schedule genertion might not cover that loop properly. For now we bail
  out as we would not optimize these loops anyway.

llvm-svn: 265280
2016-04-03 23:09:06 +00:00
Tobias Grosser 151ae32dba Revert "[FIX] Do not create a SCoP in the presence of infinite loops"
This reverts commit r265260, as it caused the following 'make check-polly'
failures:

    Polly :: ScopDetect/index_from_unpredictable_loop.ll
    Polly :: ScopInfo/multiple_exiting_blocks.ll
    Polly :: ScopInfo/multiple_exiting_blocks_two_loop.ll
    Polly :: ScopInfo/schedule-const-post-dominator-walk-2.ll
    Polly :: ScopInfo/schedule-const-post-dominator-walk.ll
    Polly :: ScopInfo/switch-5.ll

llvm-svn: 265272
2016-04-03 19:36:52 +00:00
Johannes Doerfert 2075b5d2a1 [FIX] Do not create two SAI objects for exit PHIs
If an exit PHI is written and also read in the SCoP we should not create two
  SAI objects but only one. As the read is only modeled to ensure OpenMP code
  generation knows about it we can simply use the EXIT_PHI MemoryKind for both
  accesses.

llvm-svn: 265261
2016-04-03 11:16:00 +00:00
Johannes Doerfert 7dcceb82e9 [FIX] Do not create a SCoP in the presence of infinite loops
If a loop has no exiting blocks the region covering we use during
  schedule genertion might not cover that loop properly. For now we bail
  out as we would not optimize these loops anyway.

llvm-svn: 265260
2016-04-03 11:12:39 +00:00
Tobias Grosser 6deba4ea03 Revert 264782 and 264789
These caused LNT failures due to new assertions when running with
-polly-position=before-vectorizer -polly-process-unprofitable for:

FAIL: clamscan.compile_time
FAIL: cjpeg.compile_time
FAIL: consumer-jpeg.compile_time
FAIL: shapes.compile_time
FAIL: clamscan.execution_time
FAIL: cjpeg.execution_time
FAIL: consumer-jpeg.execution_time
FAIL: shapes.execution_time

The failures have been introduced by r264782, but r264789 had to be reverted
as it depended on the earlier patch.

llvm-svn: 264885
2016-03-30 18:18:31 +00:00
Johannes Doerfert a144fb148b Exploit graph properties during domain generation
As a CFG is often structured we can simplify the steps performed
  during domain generation. When we push domain information we can
  utilize the information from a block A to build the domain of a
  block B, if A dominates B. When we pull domain information we can
  use information from a block A to build the domain of a block B
  if B post-dominates A. This patch implements both ideas and thereby
  simplifies domains that were not simplified by isl. For the FINAL
  basic block in
    test/ScopInfo/complex-successor-structure-3.ll .
  we used to build a universe set with 81 basic sets. Now it actually is
  represented as universe set.

  While the initial idea to utilize the graph structure depended on the
  dominator and post-dominator tree we can use the available region
  information as a coarse grained replacement. To this end we push the
  region entry domain to the region exit and pull it from the region
  entry for the region exit.

Differential Revision: http://reviews.llvm.org/D18450

llvm-svn: 264789
2016-03-29 21:31:05 +00:00
Johannes Doerfert e11e08bd1f Factor out "adjustDomainDimensions" function [NFC]
llvm-svn: 264782
2016-03-29 20:41:24 +00:00
Johannes Doerfert 29cb067000 Factor out "getFirstNonBoxedLoopFor" function [NFC]
llvm-svn: 264781
2016-03-29 20:32:43 +00:00
Johannes Doerfert 5fb9b21c24 Bail as early as possible
Instead of waiting for the domain construction to finish we will now
  bail as early as possible in case a complexity problem is encountered.
  This might save compile time but more importantly it makes the "abort"
  explicit. While we can always check if we invalidated the assumed
  context we can simply propagate the result of the construction back.
  This also removes the HasComplexCFG flag that was used for the very
  same reason.

Differential Revision: http://reviews.llvm.org/D18504

llvm-svn: 264775
2016-03-29 20:02:05 +00:00
Michael Kruse 88a2256a34 Revert "[ScopInfo] Fix domains after loops."
This reverts commit r264118. The approach is still under discussion.

llvm-svn: 264705
2016-03-29 07:50:52 +00:00
Johannes Doerfert 6462d8c1d9 Generalize the domain complexity restrictions
This patch applies the restrictions on the number of domain conjuncts
  also to the domain parts of piecewise affine expressions we generate.
  To this end the wording is change slightly. It was needed to support
  complex additions featuring zext-instructions but it also fixes PR27045.

  lnt profitable runs reports only little changes that might be noise:
  Compile Time:
    Polybench/[...]/2mm                     +4.34%
    SingleSource/[...]/stepanov_container   -2.43%
  Execution Time:
    External/[...]/186_crafty               -2.32%
    External/[...]/188_ammp                 -1.89%
    External/[...]/473_astar                -1.87%

llvm-svn: 264514
2016-03-26 16:17:00 +00:00
Johannes Doerfert 733ea34f38 [FIX] Handle accesses to "null" in MemIntrinsics
This fixes PR27035. While we now exclude MemIntrinsics from the
  polyhedral model if they would access "null" we could exploit this
  even more, e.g., remove all parameter combinations that would lead to
  the execution of this statement from the context.

llvm-svn: 264284
2016-03-24 13:50:04 +00:00
Johannes Doerfert 549768c01a [FIX] Verify the alias group before returning it
Similar to r262612 we need to check not only the pointer SCEV and the
type of an alias group but also the actual access instruction. The
reason is again the same: The pointer SCEV is not flow sensitive but the
access function is. In r262612 we avoided consolidating alias groups
even though the pointer SCEV and the type were the same but the access
function was not. Here it is simpler as we can simply check all members
of an alias group against the given access instruction.

llvm-svn: 264274
2016-03-24 13:22:16 +00:00
Johannes Doerfert 01b723ba43 Remove obsolete CMD option [NFC]
llvm-svn: 264270
2016-03-24 13:19:51 +00:00
Johannes Doerfert 2b470e8e61 Remove obsolete code
Since r261226 we should not see this situation any more, if so it is probably
  a bug that would only be hidden.

llvm-svn: 264269
2016-03-24 13:19:16 +00:00
Michael Kruse 49a59ca093 [ScopInfo] Fix domains after loops.
ISL can conclude additional conditions on parameters from restrictions
on loop variables. Such conditions persist when leaving the loop and the
loop variable is projected out. This results in a narrower domain for
exiting the loop than entering it and is logically impossible for
non-infinite loops.

We fix this by not adding a lower bound i>=0 when constructing BB
domains, but defer it to when also the upper bound it computed, which
was done redundantly even before this patch.

This reduces the number of LNT fails with -polly-process-unprofitable
-polly-position=before-vectorizer from 8 to 6.

llvm-svn: 264118
2016-03-22 23:27:42 +00:00
Tobias Grosser 5a8c052baf Invalidate scop on encountering a complex control flow
We bail out if current scop has a complex control flow as this could lead to
building of large domain conditions. This is to reduce compile time.  This
addresses r26382.

Contributed-by: Chris Jenneisch <chrisj@codeaurora.org>

Differential Revision: http://reviews.llvm.org/D18362

llvm-svn: 264105
2016-03-22 22:05:32 +00:00
Tobias Grosser 0904c69110 ScopInfo: Do not generate dependences for i1 values used in affine branches
Affine branches are fully modeled and regenerated from the polyhedral domain and
consequently do not require any input conditions to be propagated.

llvm-svn: 263678
2016-03-16 23:33:54 +00:00
Michael Kruse 09eb4451d2 Pass scope and LoopInfo to SCEVValidator. NFC.
The scope will be required in the following fix. This commit separates
the large changes that do not change behaviour from the small, but
functional change.

llvm-svn: 262664
2016-03-03 22:10:47 +00:00
Johannes Doerfert ac37c565b5 Fix typo [NFC]
llvm-svn: 262613
2016-03-03 12:30:19 +00:00
Johannes Doerfert df88023d2b [FIX] Consolidation of loads with same pointer but different access relation
This should fix PR19422.

  Thanks to Jeremy Huddleston Sequoia for reporting this.
  Thanks to Roman Gareev for his investigation and the reduced test case.

llvm-svn: 262612
2016-03-03 12:26:58 +00:00
Michael Kruse c7e0d9c216 Fix non-synthesizable loop exit values.
Polly recognizes affine loops that ScalarEvolution does not, in
particular those with loop conditions that depend on hoisted invariant
loads. Check for SCEVAddRec dependencies on such loops and do not
consider their exit values as synthesizable because SCEVExpander would
generate them as expressions that depend on the original induction
variables. These are not available in generated code.

llvm-svn: 262404
2016-03-01 21:44:06 +00:00