Commit Graph

13824 Commits

Author SHA1 Message Date
Adhemerval Zanella
98e40b8ddf [sanitizer] Use same shadow offset for ASAN on aarch64
This patch makes ASAN for aarch64 use the same shadow offset for all
currently supported VMAs (39 and 42 bits).  The shadow offset is the
same for 39-bit (36).  Similar to ppc64 port, aarch64 transformation
also requires to use an add instead of 'or' for 42-bit VMA.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252495 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-09 18:03:48 +00:00
Dehao Chen
b16171eac2 Add discriminators for call instructions that are from the same line and same basic block.
Summary: Call instructions that are from the same line and same basic block needs to have separate discriminators to distinguish between different callsites.

Reviewers: davidxl, dnovillo, dblaikie

Subscribers: dblaikie, probinson, llvm-commits

Differential Revision: http://reviews.llvm.org/D14464

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252492 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-09 17:30:38 +00:00
Chad Rosier
01eac64506 Simplify. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252491 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-09 16:56:06 +00:00
Oliver Stannard
1cff5e8007 GlobalOpt should maintain externally_initialized when splitting aggregates
When GlobalOpt splits an internal, global variable with an aggregate type, it
should propagate the externally_initialized flag to the newly created globals.

This makes the pass safe for our downstream use of this flag, while still
allowing some useful optimisations (such as removing dead parts of the split
aggregate) to be performed.

Differential Revision: http://reviews.llvm.org/D13382



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252490 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-09 16:47:16 +00:00
James Molloy
ae263d48b0 [LoopVectorize] Address post-commit feedback on r250032
Implemented as many of Michael's suggestions as were possible:
  * clang-format the added code while it is still fresh.
  * tried to change Value* to Instruction* in many places in computeMinimumValueSizes - unfortunately there are several places where Constants need to be handled so this wasn't possible.
  * Reduce the pass list on loop-vectorization-factors.ll.
  * Fix a bug where we were querying MinBWs for I->getOperand(0) but using MinBWs[I].

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252469 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-09 14:32:05 +00:00
Silviu Baranga
9517cbd9fb Allow LLE/LD and the loop versioning infrastructure to use SCEV predicates
Summary:
LAA currently generates a set of SCEV predicates that must be checked by users.
In the case of Loop Distribute/Loop Load Elimination, no such predicates could have
been emitted, since we don't allow stride versioning. However, in the future there
could be SCEV predicates that will need to be checked.

This change adds support for SCEV predicate versioning in the Loop Distribute, Loop
Load Eliminate and the loop versioning infrastructure.

Reviewers: anemet

Subscribers: mssimpso, sanjoy, llvm-commits

Differential Revision: http://reviews.llvm.org/D14240

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252467 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-09 13:26:09 +00:00
David Majnemer
08a70b0f2b [LoopStrengthReduce] Don't bother fixing up PHIs from EH Pad preds
We cannot really insert fixup code into a PHI's predecessor.

This fixes PR25445.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252416 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-08 05:04:07 +00:00
Sanjoy Das
226fd8ff51 Unbreak the build
My code clashed with some ilist iterator changes upstream.  Fix by
adding an explicit "&*" coercion.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252392 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-07 02:26:53 +00:00
Sanjoy Das
934f075e35 [FunctionAttrs] Add comment and clarify assertion message; NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252389 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-07 01:56:07 +00:00
Sanjoy Das
e70403f197 [FunctionAttrs] Add handling for operand bundles
Summary:
Teach the FunctionAttrs to do the right thing for IR with operand
bundles.

Reviewers: reames, chandlerc

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D14408

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252387 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-07 01:56:00 +00:00
Sanjoy Das
d044355f2d [FunctionAttrs] Fix an iterator wraparound bug
Summary:
This change fixes an iterator wraparound bug in
`determinePointerReadAttrs`.

Ideally, ++'ing off the `end()` of an iplist should result in a failed
assert, but currently iplist seems to silently wrap to the head of the
list on `end()++`.  This is why the bad behavior is difficult to
demonstrate.

Reviewers: chandlerc, reames

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D14350

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252386 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-07 01:55:53 +00:00
David Majnemer
38bab16081 [InstCombine] Teach FoldPHIArgZextsIntoPHI about EHPads
FoldPHIArgZextsIntoPHI cannot insert an instruction after the PHI if
there is an EHPad in the BB.  Doing so would result in an instruction
inserted after a terminator.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252377 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-07 00:52:53 +00:00
Duncan P. N. Exon Smith
5013c51dfc ADT: Remove last implicit ilist iterator conversions, NFC
Some implicit ilist iterator conversions have crept back into Analysis,
Transforms, Hexagon, and llvm-stress.  This removes them.

I'll commit a patch immediately after this to disallow them (in a
separate patch so that it's easy to revert if necessary).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252371 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-07 00:01:16 +00:00
David Majnemer
780c417861 [InstCombine] Don't insert an instruction after a terminator
We tried to insert a cast of a phi in a block whose terminator is an
EHPad.  This is invalid.  Do not attempt the transform in these
circumstances.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252370 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-06 23:59:23 +00:00
Akira Hatanaka
c35973bfb0 Add 'notail' marker for call instructions.
This marker prevents optimization passes from adding 'tail' or
'musttail' markers to a call. Is is used to prevent tail call
optimization from being performed on the call.

rdar://problem/22667622

Differential Revision: http://reviews.llvm.org/D12923


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252368 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-06 23:55:38 +00:00
David Majnemer
16261dd30c [InstCombine] Don't RAUW tokens with undef
Let SimplifyCFG remove unreachable BBs which define token instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252343 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-06 21:26:32 +00:00
Davide Italiano
b418909313 [SimplifyLibCalls] Don't hardcode the function name.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252342 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-06 21:05:07 +00:00
Mehdi Amini
7d84928143 Fix SLPVectorizer commutativity reordering
The SLPVectorizer had a very crude way of trying to benefit
from associativity: it tried to optimize for splat/broadcast
or in order to have the same operator on the same side.
This is benefitial to the cost model and allows more vectorization
to occur.
This patch improve the logic and make the detection optimal (locally,
we don't look at the full tree but only at the immediate children).

Should fix https://llvm.org/bugs/show_bug.cgi?id=25247

Reviewers: mzolotukhin

Differential Revision: http://reviews.llvm.org/D13996

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252337 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-06 20:17:51 +00:00
Sanjoy Das
e2b013ff76 [ValueTracking] Add parameters to isImpliedCondition; NFC
Summary:
This change makes the `isImpliedCondition` interface similar to the rest
of the functions in ValueTracking (in that it takes a DataLayout,
AssumptionCache etc.).  This is an NFC, intended to make a later diff
less noisy.

Depends on D14369

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D14391

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252333 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-06 19:01:08 +00:00
Chad Rosier
8be4aacc6e [LIR] Simplify code by making DataLayout globally accessible. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252317 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-06 16:33:57 +00:00
Peter Collingbourne
5f220beefc DI: Reverse direction of subprogram -> function edge.
Previously, subprograms contained a metadata reference to the function they
described. Because most clients need to get or set a subprogram for a given
function rather than the other way around, this created unneeded inefficiency.

For example, many passes needed to call the function llvm::makeSubprogramMap()
to build a mapping from functions to subprograms, and the IR linker needed to
fix up function references in a way that caused quadratic complexity in the IR
linking phase of LTO.

This change reverses the direction of the edge by storing the subprogram as
function-level metadata and removing DISubprogram's function field.

Since this is an IR change, a bitcode upgrade has been provided.

Fixes PR23367. An upgrade script for textual IR for out-of-tree clients is
attached to the PR.

Differential Revision: http://reviews.llvm.org/D14265

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252219 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-05 22:03:56 +00:00
Alexey Samsonov
f17835b5ce [ASan] Disable instrumentation for inalloca variables.
inalloca variables were not treated as static allocas, therefore didn't
participate in regular stack instrumentation. We don't want them to
participate in dynamic alloca instrumentation as well.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252213 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-05 21:18:41 +00:00
Davide Italiano
c18c3b8a30 [SimplifyLibCalls] Use hasFloatVersion(). NFCI.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252186 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-05 19:18:23 +00:00
James Molloy
a3bdb086c7 [SimplifyCFG] Tweak heuristic for merging conditional stores
We were correctly skipping dbginfo intrinsics and terminators, but the initial bailout wasn't, causing it to bail out on almost any block.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252152 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-05 08:40:19 +00:00
Sanjoy Das
8e56fac5c1 [FunctionAttrs] Remove a loop, NFC refactor
Summary:
Remove the loop over the uses of the CallSite in ArgumentUsesTracker.
Since we have the `Use *` for actual argument operand, we can just use
pointer subtraction.

The time complexity remains the same though (except for a vararg
argument) -- `std::advance` is O(UseIndex) for the ArgumentList
iterator.

The real motivation is to make a later change adding support for operand
bundles simpler.

Reviewers: reames, chandlerc, nlewycky

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D14363

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252141 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-05 03:04:40 +00:00
Xinliang David Li
0bf62648ad [PGO] Use template file to define runtime structures
With this change, instrumentation code and reader/write
code related to profile data structs are kept strictly
in-sync. THis will be extended to cfe and compile-rt 
references as well.

Differential Revision: http://reviews.llvm.org/D13843


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252113 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-05 00:47:26 +00:00
Davide Italiano
9496ef1fef [SimplifyLibCalls] New transformation: tan(atan(x)) -> x
This is enabled only under -ffast-math.
So, instead of emitting:
  4007b0:       50                      push   %rax
  4007b1:       e8 8a fd ff ff          callq  400540 <atanf@plt>
  4007b6:       58                      pop    %rax
  4007b7:       e9 94 fd ff ff          jmpq   400550 <tanf@plt>
  4007bc:       0f 1f 40 00             nopl   0x0(%rax)

for:
float mytan(float x) {
  return tanf(atanf(x));
}
we emit a single retq.

Differential Revision:	 http://reviews.llvm.org/D14302


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252098 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-04 23:36:56 +00:00
Eugene Zelenko
4e036ff575 Fix some Clang-tidy modernize warnings, other minor fixes.
Fixed warnings are: modernize-use-override, modernize-use-nullptr and modernize-redundant-void-arg.

Differential revision: http://reviews.llvm.org/D14312


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252087 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-04 22:32:32 +00:00
James Molloy
21ea6085dc [SimplifyCFG] Merge conditional stores
We can often end up with conditional stores that cannot be speculated. They can come from fairly simple, idiomatic code:

  if (c & flag1)
    *a = x;
  if (c & flag2)
    *a = y;
  ...

There is no dominating or post-dominating store to a, so it is not legal to move the store unconditionally to the end of the sequence and cache the intermediate result in a register, as we would like to.

It is, however, legal to merge the stores together and do the store once:

  tmp = undef;
  if (c & flag1)
    tmp = x;
  if (c & flag2)
    tmp = y;
  if (c & flag1 || c & flag2)
    *a = tmp;

The real power in this optimization is that it allows arbitrary length ladders such as these to be completely and trivially if-converted. The typical code I'd expect this to trigger on often uses binary-AND with constants as the condition (as in the above example), which means the ending condition can simply be truncated into a single binary-AND too: 'if (c & (flag1|flag2))'. As in the general case there are bitwise operators here, the ladder can often be optimized further too.

This optimization involves potentially increasing register pressure. Even in the simplest case, the lifetime of the first predicate is extended. This can be elided in some cases such as using binary-AND on constants, but not in the general case. Threading 'tmp' through all branches can also increase register pressure.

The optimization as in this patch is enabled by default but kept in a very conservative mode. It will only optimize if it thinks the resultant code should be if-convertable, and additionally if it can thread 'tmp' through at least one existing PHI, so it will only ever in the worst case create one more PHI and extend the lifetime of a predicate.

This doesn't trigger much in LNT, unfortunately, but it does trigger in a big way in a third party test suite.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252051 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-04 15:28:04 +00:00
Philip Reames
e93434193f [CVP] Fold return values if possible
In my previous change to CVP (251606), I made CVP much more aggressive about trying to constant fold comparisons. This patch is a reversal in direction. Rather than being agressive about every compare, we restore the non-block local restriction for most, and then try hard for compares feeding returns.

The motivation for this is two fold:
 * The more I thought about it, the less comfortable I got with the possible compile time impact of the other approach. There have been no reported issues, but after talking to a couple of folks, I've come to the conclusion the time probably isn't justified.
 * It turns out we need to know the context to leverage the full power of LVI. In particular, asking about something at the end of it's block (the use of a compare in a return) will frequently get more precise results than something in the middle of a block. This is an implementation detail, but it's also hard to get around since mid-block queries have to reason about possible throwing instructions and don't get to use most of LVI's block focused infrastructure. This will become particular important when combined with http://reviews.llvm.org/D14263.

Differential Revision: http://reviews.llvm.org/D14271



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252032 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-04 01:43:54 +00:00
Adam Nemet
d660541aa0 Fix unused variable warning from r252017
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252019 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-04 00:10:33 +00:00
Adam Nemet
bd67564ff2 LLE 6/6: Add LoopLoadElimination pass
Summary:
The goal of this pass is to perform store-to-load forwarding across the
backedge of a loop.  E.g.:

  for (i)
     A[i + 1] = A[i] + B[i]

  =>

  T = A[0]
  for (i)
     T = T + B[i]
     A[i + 1] = T

The pass relies on loop dependence analysis via LoopAccessAnalisys to
find opportunities of loop-carried dependences with a distance of one
between a store and a load.  Since it's using LoopAccessAnalysis, it was
easy to also add support for versioning away may-aliasing intervening
stores that would otherwise prevent this transformation.

This optimization is also performed by Load-PRE in GVN without the
option of multi-versioning.  As was discussed with Daniel Berlin in
http://reviews.llvm.org/D9548, this is inferior to a more loop-aware
solution applied here.  Hopefully, we will be able to remove some
complexity from GVN/MemorySSA as a consequence.

In the long run, we may want to extend this pass (or create a new one if
there is little overlap) to also eliminate loop-indepedent redundant
loads and store that *require* versioning due to may-aliasing
intervening stores/loads.  I have some motivating cases for store
elimination. My plan right now is to wait for MemorySSA to come online
first rather than using memdep for this.

The main motiviation for this pass is the 456.hmmer loop in SPECint2006
where after distributing the original loop and vectorizing the top part,
we are left with the critical path exposed in the bottom loop.  Being
able to promote the memory dependence into a register depedence (even
though the HW does perform store-to-load fowarding as well) results in a
major gain (~20%).  This gain also transfers over to x86: it's
around 8-10%.

Right now the pass is off by default and can be enabled
with -enable-loop-load-elim.  On the LNT testsuite, there are two
performance changes (negative number -> improvement):

  1. -28% in Polybench/linear-algebra/solvers/dynprog: the length of the
     critical paths is reduced
  2. +2% in Polybench/stencils/adi: Unfortunately, I couldn't reproduce this
     outside of LNT

The pass is scheduled after the loop vectorizer (which is after loop
distribution).  The rational is to try to reuse LAA state, rather than
recomputing it.  The order between LV and LLE is not critical because
normally LV does not touch scalar st->ld forwarding cases where
vectorizing would inhibit the CPU's st->ld forwarding to kick in.

LoopLoadElimination requires LAA to provide the full set of dependences
(including forward dependences).  LAA is known to omit loop-independent
dependences in certain situations.  The big comment before
removeDependencesFromMultipleStores explains why this should not occur
for the cases that we're interested in.

Reviewers: dberlin, hfinkel

Subscribers: junbuml, dberlin, mssimpso, rengolin, sanjoy, llvm-commits

Differential Revision: http://reviews.llvm.org/D13259

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252017 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-03 23:50:08 +00:00
Fiona Glaser
0b7ecee988 InstCombine: fix sinking of convergent calls
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251991 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-03 22:23:39 +00:00
Adam Nemet
7d1e09e79f [LAA] LLE 3/6: Rename InterestingDependence to Dependences, NFC
Summary:
We now collect all types of dependences including lexically forward
deps not just "interesting" ones.

Reviewers: hfinkel

Subscribers: rengolin, llvm-commits

Differential Revision: http://reviews.llvm.org/D13256

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251985 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-03 21:39:52 +00:00
Davide Italiano
1b506d8aa4 [SimplifyLibCalls] Add a new transformation: pow(exp(x), y) -> exp(x*y)
This one is enabled only under -ffast-math (due to rounding/overflows)
but allows us to emit shorter code.

Before (on FreeBSD x86-64):
4007f0:       50                      push   %rax
4007f1:       f2 0f 11 0c 24          movsd  %xmm1,(%rsp)
4007f6:       e8 75 fd ff ff          callq  400570 <exp2@plt>
4007fb:       f2 0f 10 0c 24          movsd  (%rsp),%xmm1
400800:       58                      pop    %rax
400801:       e9 7a fd ff ff          jmpq   400580 <pow@plt>
400806:       66 2e 0f 1f 84 00 00    nopw   %cs:0x0(%rax,%rax,1)
40080d:       00 00 00

After:
4007b0:       f2 0f 59 c1             mulsd  %xmm1,%xmm0
4007b4:       e9 87 fd ff ff          jmpq   400540 <exp2@plt>
4007b9:       0f 1f 80 00 00 00 00    nopl   0x0(%rax)

Differential Revision:	http://reviews.llvm.org/D14045


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251976 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-03 20:32:23 +00:00
Elena Demikhovsky
2c4a333422 LoopVectorizer - skip 'bitcast' between GEP and load.
Skipping 'bitcast' in this case allows to vectorize load:

  %arrayidx = getelementptr inbounds double*, double** %in, i64 %indvars.iv
  %tmp53 = bitcast double** %arrayidx to i64*
  %tmp54 = load i64, i64* %tmp53, align 8

Differential Revision http://reviews.llvm.org/D14112



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251907 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-03 10:29:34 +00:00
Tobias Grosser
0efe7b620e Revert "[IndVarSimplify] Rewrite loop exit values with their initial values from loop preheader"
Commit 251839 triggers miscompiles on some bots:

http://lab.llvm.org:8011/builders/perf-x86_64-penryn-O3-polly-fast/builds/13723

(The commit is listed in 13722, but due to an existing failure introduced in
13721 and reverted in 13723 the failure is only visible in 13723)

To verify r251839 is indeed the only change that triggered the buildbot failures
and to ensure the buildbots remain green while investigating I temporarily
revert this commit. At the current state it is unclear if this commit introduced
some miscompile or if it only exposed code to Polly that is subsequently
miscompiled by Polly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251901 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-03 07:14:39 +00:00
Teresa Johnson
0292f065c1 Restore "Support for ThinLTO function importing and symbol linking."
This restores commit r251837, with the new library dependence added to
llvm-link/Makefile to address bot failures.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251866 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-03 00:14:15 +00:00
Davide Italiano
e8e35e60d8 [SimplifyLibCalls] Remove variables that are not used. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251852 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-02 23:07:14 +00:00
Cong Hou
c895fd0d67 Add a flag vectorizer-maximize-bandwidth in loop vectorizer to enable using larger vectorization factor.
To be able to maximize the bandwidth during vectorization, this patch provides a new flag vectorizer-maximize-bandwidth. When it is turned on, the vectorizer will determine the vectorization factor (VF) using the smallest instead of widest type in the loop. To avoid increasing register pressure too much, estimates of the register usage for different VFs are calculated so that we only choose a VF when its register usage doesn't exceed the number of available registers.

This is the second attempt to submit this patch. The first attempt got a test failure on ARM. This patch is updated to try to fix the failure (more specifically, by handling the case when VF=1).

Differential revision: http://reviews.llvm.org/D8943



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251850 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-02 22:53:48 +00:00
Sanjay Patel
9e9408f07b don't repeat function names in comments; NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251846 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-02 22:34:55 +00:00
Davide Italiano
256403a9af [SimplifyLibCalls] Merge two if statements. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251845 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-02 22:33:26 +00:00
Teresa Johnson
3d95431a33 Revert "Support for ThinLTO function importing and symbol linking."
This reverts commit r251837, due to a number of bot failures of the form:

/home/grosser/buildslave/perf-x86_64-penryn-O3-polly-fast/llvm.obj/tools/llvm-link/Release+Asserts/llvm-link.o:llvm-link.cpp:function
loadIndex(llvm::LLVMContext&, llvm::Module const*): error: undefined
reference to
'llvm::object::FunctionIndexObjectFile::create(llvm::MemoryBufferRef,
llvm::LLVMContext&, llvm::Module const*, bool)'
/home/grosser/buildslave/perf-x86_64-penryn-O3-polly-fast/llvm.obj/tools/llvm-link/Release+Asserts/llvm-link.o:llvm-link.cpp:function
loadIndex(llvm::LLVMContext&, llvm::Module const*): error: undefined
reference to 'llvm::object::FunctionIndexObjectFile::takeIndex()'

I'm not sure why these are happening - I added Object to the requred
libraries in tools/llvm-link/LLVMBuild.txt and the LLVM_LINK_COMPONENTS
in tools/llvm-link/CMakeLists.txt. Confirmed for my build that these
symbols come out of libLLVMObject.a. What am I missing?

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251841 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-02 22:17:32 +00:00
Chen Li
fb81c7b828 [IndVarSimplify] Rewrite loop exit values with their initial values from loop preheader
Summary:
This patch adds support to check if a loop has loop invariant conditions which lead to loop exits. If so, we know that if the exit path is taken, it is at the first loop iteration. If there is an induction variable used in that exit path whose value has not been updated, it will keep its initial value passing from loop preheader. We can therefore rewrite the exit value with
its initial value. This will help remove phis created by LCSSA and enable other optimizations like loop unswitch.


Reviewers: sanjoy

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D13974

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251839 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-02 22:00:15 +00:00
Teresa Johnson
5aa157fab6 Support for ThinLTO function importing and symbol linking.
Summary:
Support for necessary linkage changes and symbol renaming during
ThinLTO function importing.

Also includes llvm-link support for manually importing functions
and associated llvm-link based tests.

Note that this does not include support for intelligently importing
metadata, which is currently imported duplicate times. That support will
be in the follow-on patch, and currently is ignored by the tests.

Reviewers: dexonsmith, joker.eph, davidxl

Subscribers: tobiasvk, tejohnson, llvm-commits

Differential Revision: http://reviews.llvm.org/D13515

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251837 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-02 21:39:10 +00:00
David Blaikie
5c6a6f6ad5 StringRef-ify DiagnosticInfoSampleProfile::Filename
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251823 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-02 20:01:13 +00:00
Teresa Johnson
9dd98c0eab Clang format a few prior patches (NFC)
I had clang formatted my earlier patches using the wrong style.
Reformatted with the LLVM style.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251812 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-02 18:02:11 +00:00
Artur Pilipenko
bf7f89f132 Preserve load alignment and dereferenceable metadata during some transformations
Reviewed By: hfinkel

Differential Revision: http://reviews.llvm.org/D13953


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251809 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-02 17:53:51 +00:00
Silviu Baranga
a0b73c263e [SCEV][LV] Add SCEV Predicates and use them to re-implement stride versioning
Summary:
SCEV Predicates represent conditions that typically cannot be derived from
static analysis, but can be used to reduce SCEV expressions to forms which are
usable for different optimizers.

ScalarEvolution now has the rewriteUsingPredicate method which can simplify a
SCEV expression using a SCEVPredicateSet. The normal workflow of a pass using
SCEVPredicates would be to hold a SCEVPredicateSet and every time assumptions
need to be made a new SCEV Predicate would be created and added to the set.
Each time after calling getSCEV, the user will call the rewriteUsingPredicate
method.

We add two types of predicates
SCEVPredicateSet - implements a set of predicates
SCEVEqualPredicate - tests for equality between two SCEV expressions

We use the SCEVEqualPredicate to re-implement stride versioning. Every time we
version a stride, we will add a SCEVEqualPredicate to the context.
Instead of adding specific stride checks, LoopVectorize now adds a more
generic SCEV check.

We only need to add support for this in the LoopVectorizer since this is the
only pass that will do stride versioning.

Reviewers: mzolotukhin, anemet, hfinkel, sanjoy

Subscribers: sanjoy, hfinkel, rengolin, jmolloy, llvm-commits

Differential Revision: http://reviews.llvm.org/D13595

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251800 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-02 14:41:02 +00:00
Davide Italiano
4784e1362f Simplify a check. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251757 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-01 00:09:16 +00:00