Commit Graph

3580 Commits

Author SHA1 Message Date
James Molloy 171fdac7ce [SimplifyCFG] Add a workaround to fix PR30188
We're sinking stores, which is a good thing, but in the process creating selects for the store address operand, which SROA/Mem2Reg can't look through, which caused serious regressions.

The real fix is in SROA, which I'll be looking into.

llvm-svn: 280219
2016-08-31 10:46:45 +00:00
James Molloy 8e69b032e5 [SimplifyCFG] Improve FoldValueComparisonIntoPredecessors to handle more cases
A very important case is not handled here: multiple arcs to a single block with a PHI. Consider:

    a:
      %1 = icmp %b, 1
      br %1, label %c, label %e
    c:
      %2 = icmp %b, 2
      br %2, label %d, label %e
    d:
      br %e
    e:
      phi [0, %a], [1, %c], [2, %d]

FoldValueComparisonIntoPredecessors will refuse to fold this, as it doesn't know how to deal with two arcs to a common destination with different PHI values. The answer is obvious - just split all conflicting arcs.

llvm-svn: 280218
2016-08-31 10:46:39 +00:00
James Molloy c53b40b509 [SimplifyCFG] Handle tail-sinking of more than 2 incoming branches
This was a real restriction in the original version of SinkIfThenCodeToEnd. Now it's been rewritten, the restriction can be lifted.

As part of this, we handle a very common and useful case where one of the incoming branches is actually conditional. Consider:

   if (a)
     x(1);
   else if (b)
     x(2);

This produces the following CFG:

         [if]
        /    \
      [x(1)] [if]
        |     | \
        |     |  \
        |  [x(2)] |
         \    |  /
          [ end ]

[end] has two unconditional predecessor arcs and one conditional. The conditional refers to the implicit empty 'else' arc. This same pattern can also be caused by an empty default block in a switch.

We can't sink the call to x() down to end because no call to x() happens on the third incoming arc (assume that x() has sideeffects for the sake of argument; if something is safe to speculate we could indeed sink nevertheless but this cannot happen in the general case and causes many extra selects).

We are now able to detect this case and split off the unconditional arcs to a common successor:

         [if]
        /    \
      [x(1)] [if]
        |     | \
        |     |  \
        |  [x(2)] |
         \   /    |
     [sink.split] |
           \     /
           [ end ]

Now we can sink the call to x() into %sink.split. This can cause significant code simplification in many testcases.

llvm-svn: 280217
2016-08-31 10:46:33 +00:00
James Molloy 55bd04cd20 [SimplifyCFG] Change the algorithm in SinkThenElseCodeToEnd
r279460 rewrote this function to be able to handle more than two incoming edges and took pains to ensure this didn't regress anything.

This time we change the logic for determining if an instruction should be sunk. Previously we used a single pass greedy algorithm - sink instructions until one requires more than one PHI node or we run out of instructions to sink.

This had the problem that sinking instructions that had non-identical but trivially the same operands needed extra logic so we sunk them aggressively. For example:

    %a = load i32* %b          %d = load i32* %b
    %c = gep i32* %a, i32 0    %e = gep i32* %d, i32 1

Sinking %c and %e would naively require two PHI merges as %a != %d. But the loads are obviously equivalent (and maybe can't be hoisted because there is no common predecessor).

This is why we implemented the fairly complex function areValuesTriviallySame(), to look through trivial differences like this. However it's just not clever enough.

Instead, throw areValuesTriviallySame away, use pointer equality to check equivalence of operands and switch to a two-stage algorithm.

In the "scan" stage, we look at every sinkable instruction in isolation from end of block to front. If it's sinkable, we keep track of all operands that required PHI merging.

In the "sink" stage, we iteratively sink the last non-terminator in the source blocks. But when calculating how many PHIs are actually required to be inserted (to work out if we should stop or not) we remove any values that have already been sunk from the set of PHI-merges required, which allows us to be more aggressive.

This turns an algorithm with potentially recursive lookahead (looking through GEPs, casts, loads and any other instruction potentially not CSE'd) to two linear scans.

llvm-svn: 280216
2016-08-31 10:46:23 +00:00
James Molloy 923e98c232 [SimplifyCFG] Tail-merge calls with sideeffects
This was deliberately disabled during my rewrite of SinkIfThenToEnd to keep behaviour
at least vaguely consistent with the previous version and keep it as close to NFC as
I could.

There's no real reason not to merge sideeffect calls though, so let's do it! Small fixup
along the way to ensure we don't create indirect calls.

Should fix PR28964.

llvm-svn: 280215
2016-08-31 10:46:16 +00:00
James Molloy d13b1239e4 [SimplifyCFG] Properly CSE metadata in SinkThenElseCodeToEnd
This was missing, meaning the metadata in sunk instructions was potentially bogus and could cause miscompiles.

llvm-svn: 280072
2016-08-30 10:56:08 +00:00
Tim Northover c10c33444e ASan: remove variable only used in assertions build
llvm-svn: 279990
2016-08-29 19:12:20 +00:00
Vitaly Buka db331d8be7 [asan] Separate calculation of ShadowBytes from calculating ASanStackFrameLayout
Summary: No functional changes, just refactoring to make D23947 simpler.

Reviewers: eugenis

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D23954

llvm-svn: 279982
2016-08-29 17:41:29 +00:00
David Majnemer e8fd5f9ffd [SimplifyCFG] Hoisting invalidates metadata
We forgot to remove optimization metadata when performing hosting during
FoldTwoEntryPHINode.

This fixes PR29163.

llvm-svn: 279980
2016-08-29 17:14:08 +00:00
Adam Nemet 4f155b6e91 [LoopUnroll] Use OptimizationRemarkEmitter directly not via the analysis pass
We can't mark ORE (a function pass) preserved as required by the loop
passes because that is how we ensure that the required passes like
LazyBFI are all available any time ORE is used.  See the new comments in
the patch.

Instead we use it directly just like the inliner does in D22694.

As expected there is some additional overhead after removing the caching
provided by analysis passes.  The worst case, I measured was
LNT/CINT2006_ref/401.bzip2 which regresses by 12%.  As before, this only
affects -Rpass-with-hotness and not default compilation.

llvm-svn: 279829
2016-08-26 15:58:34 +00:00
Wei Mi 59ca96636d [UNROLL] Postpone ScalarEvolution::forgetLoop after TripCountSC is expanded
when unroll runtime iteration loop.

In llvm::UnrollRuntimeLoopRemainder, if the loop to be unrolled is the inner
loop inside a loop nest, the scalar evolution needs to be dropped for its
parent loop which is done by ScalarEvolution::forgetLoop. However, we can
postpone forgetLoop to the end of UnrollRuntimeLoopRemainder so TripCountSC
expansion can still reuse existing value.

Differential Revision: https://reviews.llvm.org/D23572

llvm-svn: 279748
2016-08-25 16:17:18 +00:00
George Burgess IV 7f414b90ab [MemorySSA] Remove unused field. NFC.
Given that we're not currently using blocker info, and whether or not we
will end up using it it is unclear, don't waste 8 (or 4) bytes of memory
per path node.

llvm-svn: 279493
2016-08-22 23:40:01 +00:00
Daniel Berlin 3d512a2dc2 MSSA: Factor out phi node placement
llvm-svn: 279462
2016-08-22 19:14:30 +00:00
Daniel Berlin 868381bff6 MSSA: Only rename accesses whose defining access is nullptr
llvm-svn: 279461
2016-08-22 19:14:16 +00:00
James Molloy 5bf2114265 [SimplifyCFG] Rewrite SinkThenElseCodeToEnd
[Recommitting now an unrelated assertion in SROA is sorted out]

The new version has several advantages:
  1) IMSHO it's more readable and neater
  2) It handles loads and stores properly
  3) It can handle any number of incoming blocks rather than just two. I'll be taking advantage of this in a followup patch.

With this change we can now finally sink load-modify-store idioms such as:

    if (a)
      return *b += 3;
    else
      return *b += 4;

    =>

    %z = load i32, i32* %y
    %.sink = select i1 %a, i32 5, i32 7
    %b = add i32 %z, %.sink
    store i32 %b, i32* %y
    ret i32 %b

When this works for switches it'll be even more powerful.

Round 4. This time we should handle all instructions correctly, and not replace any operands that need to be constant with variables.

This was really hard to determine safely, so the helper function should be put into the Instruction API. I'll do that as a followup.

llvm-svn: 279460
2016-08-22 19:07:15 +00:00
James Molloy 475f4a763f Revert "[SimplifyCFG] Rewrite SinkThenElseCodeToEnd"
This reverts commit r279443. It caused buildbot failures.

llvm-svn: 279447
2016-08-22 18:13:12 +00:00
James Molloy 353052698a [SimplifyCFG] Rewrite SinkThenElseCodeToEnd
The new version has several advantages:
  1) IMSHO it's more readable and neater
  2) It handles loads and stores properly
  3) It can handle any number of incoming blocks rather than just two. I'll be taking advantage of this in a followup patch.

With this change we can now finally sink load-modify-store idioms such as:

    if (a)
      return *b += 3;
    else
      return *b += 4;

    =>

    %z = load i32, i32* %y
    %.sink = select i1 %a, i32 5, i32 7
    %b = add i32 %z, %.sink
    store i32 %b, i32* %y
    ret i32 %b

When this works for switches it'll be even more powerful.

Round 4. This time we should handle all instructions correctly, and not replace any operands that need to be constant with variables.

This was really hard to determine safely, so the helper function should be put into the Instruction API. I'll do that as a followup.

llvm-svn: 279443
2016-08-22 17:40:23 +00:00
Vitaly Buka f9fd63ad39 [asan] Add support of lifetime poisoning into ComputeASanStackFrameLayout
Summary:
We are going to combine poisoning of red zones and scope poisoning.

PR27453

Reviewers: kcc, eugenis

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D23623

llvm-svn: 279373
2016-08-20 16:48:24 +00:00
Vitaly Buka e149b392a8 Revert "[asan] Add support of lifetime poisoning into ComputeASanStackFrameLayout"
This reverts commit r279020.

Speculative revert in hope to fix asan test on arm.

llvm-svn: 279332
2016-08-19 22:12:58 +00:00
Reid Kleckner 98a48afa5d Revert "[SimplifyCFG] Rewrite SinkThenElseCodeToEnd"
This reverts commit r279229. It breaks intrinsic function calls in
diamonds.

llvm-svn: 279313
2016-08-19 20:22:39 +00:00
David Majnemer 5554edabef [CloneFunction] Don't remove unrelated nodes from the CGSSC
CGSCC use a WeakVH to track call sites.  RAUW a call within a function
can result in that WeakVH getting confused about whether or not the call
site is still around.

llvm-svn: 279268
2016-08-19 16:37:40 +00:00
James Molloy 11a1936b70 [SimplifyCFG] Rewrite SinkThenElseCodeToEnd
The new version has several advantages:
  1) IMSHO it's more readable and neater
  2) It handles loads and stores properly
  3) It can handle any number of incoming blocks rather than just two. I'll be taking advantage of this in a followup patch.

With this change we can now finally sink load-modify-store idioms such as:

    if (a)
      return *b += 3;
    else
      return *b += 4;

    =>

    %z = load i32, i32* %y
    %.sink = select i1 %a, i32 5, i32 7
    %b = add i32 %z, %.sink
    store i32 %b, i32* %y
    ret i32 %b

When this works for switches it'll be even more powerful.

llvm-svn: 279229
2016-08-19 10:10:27 +00:00
Vitaly Buka d5ec14989d [asan] Add support of lifetime poisoning into ComputeASanStackFrameLayout
Summary:
We are going to combine poisoning of red zones and scope poisoning.

PR27453

Reviewers: kcc, eugenis

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D23623

llvm-svn: 279020
2016-08-18 00:56:58 +00:00
Chandler Carruth 67fc52f067 [PM] Port the always inliner to the new pass manager in a much more
minimal and boring form than the old pass manager's version.

This pass does the very minimal amount of work necessary to inline
functions declared as always-inline. It doesn't support a wide array of
things that the legacy pass manager did support, but is alse ... about
20 lines of code. So it has that going for it. Notably things this
doesn't support:

- Array alloca merging
  - To support the above, bottom-up inlining with careful history
    tracking and call graph updates
- DCE of the functions that become dead after this inlining.
- Inlining through call instructions with the always_inline attribute.
  Instead, it focuses on inlining functions with that attribute.

The first I've omitted because I'm hoping to just turn it off for the
primary pass manager. If that doesn't pan out, I can add it here but it
will be reasonably expensive to do so.

The second should really be handled by running global-dce after the
inliner. I don't want to re-implement the non-trivial logic necessary to
do comdat-correct DCE of functions. This means the -O0 pipeline will
have to be at least 'always-inline,global-dce', but that seems
reasonable to me. If others are seriously worried about this I'd like to
hear about it and understand why. Again, this is all solveable by
factoring that logic into a utility and calling it here, but I'd like to
wait to do that until there is a clear reason why the existing
pass-based factoring won't work.

The final point is a serious one. I can fairly easily add support for
this, but it seems both costly and a confusing construct for the use
case of the always inliner running at -O0. This attribute can of course
still impact the normal inliner easily (although I find that
a questionable re-use of the same attribute). I've started a discussion
to sort out what semantics we want here and based on that can figure out
if it makes sense ta have this complexity at O0 or not.

One other advantage of this design is that it should be quite a bit
faster due to checking for whether the function is a viable candidate
for inlining exactly once per function instead of doing it for each call
site.

Anyways, hopefully a reasonable starting point for this pass.

Differential Revision: https://reviews.llvm.org/D23299

llvm-svn: 278896
2016-08-17 02:56:20 +00:00
Duncan P. N. Exon Smith 0a12729f99 SimplifyCFG: Avoid dereferencing end()
When comparing a User* to a BasicBlock::iterator in
passingValueIsAlwaysUndefined, don't dereference the iterator in case it
is end().

llvm-svn: 278872
2016-08-16 23:57:56 +00:00
David Majnemer 744a8753db Preserve the assumption cache more often
We were clearing it out in LoopUnswitch and InlineFunction instead of
attempting to preserve it.

llvm-svn: 278860
2016-08-16 22:07:32 +00:00
David Majnemer 110522bc0f [LoopUnroll] Don't clear out the AssumptionCache on each loop
Clearing out the AssumptionCache can cause us to rescan the entire
function for assumes.  If there are many loops, then we are scanning
over the entire function many times.

Instead of clearing out the AssumptionCache, register all cloned
assumes.

llvm-svn: 278854
2016-08-16 21:09:46 +00:00
Reid Kleckner 70a600b8bb Revert "[SimplifyCFG] Rewrite SinkThenElseCodeToEnd"
This reverts commit r278660.

It causes downstream assertion failure in InstCombine on shuffle
instructions. Comes up in __mm_swizzle_epi32.

llvm-svn: 278672
2016-08-15 15:42:31 +00:00
James Molloy 9a3c82f5cf [SimplifyCFG] Rewrite SinkThenElseCodeToEnd
The new version has several advantages:
  1) IMSHO it's more readable and neater
  2) It handles loads and stores properly
  3) It can handle any number of incoming blocks rather than just two. I'll be taking advantage of this in a followup patch.

With this change we can now finally sink load-modify-store idioms such as:

    if (a)
      return *b += 3;
    else
      return *b += 4;

    =>

    %z = load i32, i32* %y
    %.sink = select i1 %a, i32 5, i32 7
    %b = add i32 %z, %.sink
    store i32 %b, i32* %y
    ret i32 %b

When this works for switches it'll be even more powerful.

llvm-svn: 278660
2016-08-15 08:04:56 +00:00
Reid Kleckner 6ee00a2602 [Inliner] Don't treat inalloca allocas as static
They aren't static, and moving them to the entry block across something
else will only result in tears.

Root cause of http://crbug.com/636558.

llvm-svn: 278571
2016-08-12 22:23:04 +00:00
David L Kreitzer 9667417a1a Fixed typo.
llvm-svn: 278565
2016-08-12 21:06:53 +00:00
Michael Kuperstein 31b8399beb [PM] Port LowerInvoke to the new pass manager
llvm-svn: 278531
2016-08-12 17:28:27 +00:00
Teresa Johnson 4223dd8559 [PM] Port NameAnonFunction pass to new pass manager
Summary:
Port the NameAnonFunction pass and add a test.

Depends on D23439.

Reviewers: mehdi_amini

Subscribers: llvm-commits, mehdi_amini

Differential Revision: https://reviews.llvm.org/D23440

llvm-svn: 278509
2016-08-12 14:03:36 +00:00
David Majnemer c700490f48 Use the range variant of remove_if instead of unpacking begin/end
No functionality change is intended.

llvm-svn: 278475
2016-08-12 04:32:37 +00:00
David Majnemer 42531260b3 Use the range variant of find/find_if 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: 278469
2016-08-12 03:55:06 +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
Daniel Berlin da2f38e0f4 [MSSA] Use is_contained
llvm-svn: 278418
2016-08-11 21:26:50 +00:00
David Majnemer 0a16c22846 Use range algorithms instead of unpacking begin/end
No functionality change is intended.

llvm-svn: 278417
2016-08-11 21:15:00 +00:00
Rong Xu 63f970ee24 Fix LCSSA increased compile time
We are seeing r276077 drastically increasing compiler time for our larger
benchmarks in PGO profile generation build (both clang based and IR based
mode) -- it can be 20x slower than without the patch (like from 30 secs to
780 secs)

The increased time are all in pass LCSSA. The problematic code is about
PostProcessPHIs after use-rewrite. Note that the InsertedPhis from ssa_updater
is accumulating (never been cleared). Since the inserted PHIs are added to the
candidate for each rewrite, The earlier ones will be repeatedly added. Later
when adding the new PHIs to the work-list, we don't check the duplication
either. This can result in extremely long work-list that containing tons of
duplicated PHIs.

This patch fixes the issue by hoisting the code out of the loop.

Differential Revision: http://reviews.llvm.org/D23344

llvm-svn: 278250
2016-08-10 17:49:11 +00:00
Davide Italiano 873219c406 [SimplifyLibCalls] Restore the old behaviour, emit a libcall.
Hal pointed out that the semantic of our intrinsic and the libc
call are slightly different. Add a comment while I'm here to
explain why we can't emit an intrinsic. Thanks Hal!

llvm-svn: 278200
2016-08-10 06:33:32 +00:00
Michael Zolotukhin aae168f993 [LoopSimplify] Rebuild LCSSA for the inner loop after separating nested loops.
Summary:
This hopefully fixes PR28825. The problem now was that a value from the
original loop was used in a subloop, which became a sibling after separation.
While a subloop doesn't need an lcssa phi node, a sibling does, and that's
where we broke LCSSA. The most natural way to fix this now is to simply call
formLCSSA on the original loop: it'll do what we've been doing before plus
it'll cover situations described above.

I think we don't need to run formLCSSARecursively here, and we have an assert
to verify this (I've tried testing it on LLVM testsuite + SPECs). I'd be happy
to be corrected here though.

I also changed a run line in the test from '-lcssa -loop-unroll' to
'-lcssa -loop-simplify -indvars', because it exercises LCSSA
preservation to the same extent, but also makes less unrelated
transformation on the CFG, which makes it easier to verify.

Reviewers: chandlerc, sanjoy, silvas

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D23288

llvm-svn: 278173
2016-08-09 22:44:56 +00:00
Sean Silva 36e0d01e13 Consistently use FunctionAnalysisManager
Besides a general consistently benefit, the extra layer of indirection
allows the mechanical part of https://reviews.llvm.org/D23256 that
requires touching every transformation and analysis to be factored out
cleanly.

Thanks to David for the suggestion.

llvm-svn: 278077
2016-08-09 00:28:15 +00:00
Michael Zolotukhin 2f50725dbd [LoopUnroll] Simplify loops created by unrolling.
Summary:
Currently loop-unrolling doesn't preserve loop-simplified form. This patch
fixes it by resimplifying affected loops.

Reviewers: chandlerc, sanjoy, hfinkel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D23148

llvm-svn: 278038
2016-08-08 19:02:15 +00:00
Geoff Berry 290a13e7c7 [MemorySSA] Fix windows build breakage caused by r278028
r278028: [MemorySSA] Ensure address stability of MemorySSA object.
llvm-svn: 278035
2016-08-08 18:27:22 +00:00
Geoff Berry cdf5333f6f [MemorySSA] Ensure address stability of MemorySSA object.
Summary:
Ensure that the MemorySSA object never changes address when using the
new pass manager since the walkers contained by MemorySSA cache pointers
to it at construction time.  This is achieved by wrapping the
MemorySSAAnalysis result in a unique_ptr.  Also add some asserts that
check for this bug.

Reviewers: george.burgess.iv, dberlin

Subscribers: mcrosier, hfinkel, chandlerc, silvas, llvm-commits

Differential Revision: https://reviews.llvm.org/D23171

llvm-svn: 278028
2016-08-08 17:52:01 +00:00
Sean Silva 0873e7d218 Add some comments linking back to PR28400.
Thanks to Mehdi for the suggestion!

llvm-svn: 277984
2016-08-08 07:03:49 +00:00
Sean Silva 7f21f4b264 [PM] More workaround for PR28400
llvm-svn: 277982
2016-08-08 05:38:06 +00:00
Daniel Berlin 4b4c722e79 [MSSA] Fix PR28880 by fixing use optimizer's lower bound tracking behavior.
Summary:
In the use optimizer, we need to keep of whether the lower bound still
dominates us or else we may decide a lower bound is still valid when it
is not due to intervening pushes/pops.  Fixes PR28880 (and probably a
bunch of other things).

Reviewers: george.burgess.iv

Subscribers: MatzeB, llvm-commits, sebpop

Differential Revision: https://reviews.llvm.org/D23237

llvm-svn: 277978
2016-08-08 04:44:53 +00:00
Eli Friedman 02419a9849 [JumpThreading] Fix handling of aliasing metadata.
Summary:
The correctness fix here is that when we CSE a load with another load,
we need to combine the metadata on the two loads. This matches the
behavior of other passes, like instcombine and GVN.

There's also a minor optimization improvement here: for load PRE, the
aliasing metadata on the inserted load should be the same as the
metadata on the original load. Not sure why the old code was throwing
it away.

Issue found by inspection.

Differential Revision: http://reviews.llvm.org/D21460

llvm-svn: 277977
2016-08-08 04:10:22 +00:00
Davide Italiano e3b916d164 [SimplifyLibCalls] Emit sqrt intrinsic instead of a libcall.
llvm-svn: 277972
2016-08-08 03:23:01 +00:00
Davide Italiano 27da131f32 [SLC] Emit an intrinsic instead of a libcall for pow.
Differential Revision:  https://reviews.llvm.org/D22104

llvm-svn: 277963
2016-08-07 20:27:03 +00:00
Michael Zolotukhin 442b82f0eb Revert "Revert "[LoopSimplify] Fix updating LCSSA after separating nested loops.""
This reverts commit r277901. Reaaply the commit as it looks like it has
nothing to do with the bots failures.

llvm-svn: 277946
2016-08-07 01:56:54 +00:00
Benjamin Kramer b7d3311c77 Move helpers into anonymous namespaces. NFC.
llvm-svn: 277916
2016-08-06 11:13:10 +00:00
Michael Zolotukhin 09cf304ebc Revert "[LoopSimplify] Fix updating LCSSA after separating nested loops."
This reverts commit r277877.
Try to appease clang-x64-ninja-win7 buildbot.

llvm-svn: 277901
2016-08-06 01:48:51 +00:00
Daniel Berlin 7ac3d74017 [MSSA] Use depth first iterator instead of custom version.
Summary:
Originally the plan was to use the custom worklist to do some block popping,
and because we don't actually need a visited set. The custom one we have
here is slightly broken, and it's not worth fixing vs using depth_first_iterator since we aren't going to go the route we originally
were.

Fixes PR28874
Reviewers: george.burgess.iv

Subscribers: llvm-commits, gberry

Differential Revision: https://reviews.llvm.org/D23187

llvm-svn: 277880
2016-08-05 22:09:14 +00:00
Michael Zolotukhin 4c65c3596a [LoopSimplify] Fix updating LCSSA after separating nested loops.
This fixes PR28825. The problem was that we only checked if a value from
a created inner loop is used in the outer loop, and fixed LCSSA for
them. But we missed to fixup LCSSA for values used in exits of the outer
loop.

llvm-svn: 277877
2016-08-05 21:52:58 +00:00
Daniel Berlin 7af95876cf [MSSA] Match assert vs llvm_unreachable style in verification functions.
llvm-svn: 277873
2016-08-05 21:47:20 +00:00
Daniel Berlin 2919b1c41b Rewrite domination verifier to handle local domination as well.
Summary:
Rewrite domination verifier to handle local domination as well.
This catches a bug Geoff Berry noticed.

Reviewers: george.burgess.iv

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D23184

llvm-svn: 277872
2016-08-05 21:46:52 +00:00
Davide Italiano 500929df9c [FlattenCFG] Simplify + remove unused variable. NFCI.
llvm-svn: 277864
2016-08-05 20:53:35 +00:00
Dehao Chen 17c6afc35b Do not assign new discriminator for all intrinsics.
Summary: We do not care about intrinsic calls when assigning discriminators.

Reviewers: davidxl, dnovillo

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D23212

llvm-svn: 277843
2016-08-05 17:56:49 +00:00
Benjamin Kramer aa160c22f7 [SimplifyCFG] Make range reduction code deterministic.
This generated IR based on the order of evaluation, which is different
between GCC and Clang. With that in mind you get bootstrap miscompares
if you compare a Clang built with GCC-built Clang vs. Clang built with
Clang-built Clang. Diagnosing that made my head hurt.

This also reverts commit r277337, which "fixed" the test case.

llvm-svn: 277820
2016-08-05 14:55:02 +00:00
David Majnemer 4eefd6bca4 Forgot the dyn_cast_or_null intended for r277691.
llvm-svn: 277693
2016-08-04 04:47:18 +00:00
David Majnemer 909793fa63 Reinstate "[CloneFunction] Don't remove side effecting calls"
This reinstates r277611 + r277614 and reverts r277642.  A cast_or_null
should have been a dyn_cast_or_null.

llvm-svn: 277691
2016-08-04 04:24:02 +00:00
George Burgess IV 363da6f589 [MSSA] Fix a bug in MemorySSA's move ctor.
Not a correctness issue, but it would be nice if we didn't have to
recompute our block numbering (worst-case) every time we move MSSA.

llvm-svn: 277652
2016-08-03 21:07:52 +00:00
Reid Kleckner a6be60871f Revert "[CloneFunction] Don't remove side effecting calls"
This reverts commit r277611 and the followup r277614.

Bootstrap builds and chromium builds are crashing during inlining after
this change.

llvm-svn: 277642
2016-08-03 20:01:01 +00:00
George Burgess IV f7672854f0 [MSSA] clang-format. NFC.
Didn't want to fold this in with r277640, since it touches bits that
aren't entirely related to r277640.

llvm-svn: 277641
2016-08-03 19:59:11 +00:00
George Burgess IV 024f3d2683 [MSSA] Add special handling for invariant/constant loads.
This is a follow-up to r277637. It teaches MemorySSA that invariant
loads (and loads of provably constant memory) are always liveOnEntry.

llvm-svn: 277640
2016-08-03 19:57:02 +00:00
George Burgess IV 82e355ce48 [MSSA] Add logic for special handling of atomics/volatiles.
This patch makes MemorySSA recognize atomic/volatile loads, and makes
MSSA treat said loads specially. This allows us to be a bit more
aggressive in some cases.

Administrative note: Revision was LGTM'ed by reames in person.
Additionally, this doesn't include the `invariant.load` recognition in
the differential revision, because I feel it's better to commit that
separately. Will commit soon.

Differential Revision: https://reviews.llvm.org/D16875

llvm-svn: 277637
2016-08-03 19:39:54 +00:00
David Majnemer fa8ef91748 [CloneFunction] Don't crash if the value map doesn't hold something
It is possible for the value map to not have an entry for some value
that has already been removed.

I don't have a testcase, this is fall-out from a buildbot.

llvm-svn: 277614
2016-08-03 17:37:10 +00:00
David Majnemer fad0490869 [CloneFunction] Don't remove side effecting calls
We were able to figure out that the result of a call is some constant.
While propagating that fact, we added the constant to the value map.
This is problematic because it results in us losing the call site when
processing the value map.

This fixes PR28802.

llvm-svn: 277611
2016-08-03 17:12:47 +00:00
George Burgess IV 14633b5cd3 [MSSA] Fix a caching bug.
This fixes a bug where we'd sometimes cache overly-conservative results
with our walker. This bug was made more obvious by r277480, which makes
our cache far more spotty than it was. Test case is llvm-unit, because
we're likely going to use CachingWalker only for def optimization in the
future.

The bug stems from that there was a place where the walker assumed that
`DefNode.Last` was a valid target to cache to when failing to optimize
phis. This is sometimes incorrect if we have a cache hit. The fix is to
use the thing we *can* assume is a valid target to cache to. :)

llvm-svn: 277559
2016-08-03 01:22:19 +00:00
Daniel Berlin df10119e4e Support for lifetime begin/end markers in the MemorySSA use optimizer
Summary: Depends on D23072

Reviewers: george.burgess.iv

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D23076

llvm-svn: 277553
2016-08-03 00:01:46 +00:00
Piotr Padlewski 47509f6185 Imported statistics types changes
Reviewers: tejohnson, eraman

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D22980

llvm-svn: 277534
2016-08-02 22:18:47 +00:00
Daniel Berlin dff31deb1e Move to having a single real instructionClobbersQuery
Summary: We really want to move towards MemoryLocOrCall (or fix AA) everywhere, but for now, this lets us have a single instructionClobbersQuery.

Reviewers: george.burgess.iv

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D23072

llvm-svn: 277530
2016-08-02 21:57:52 +00:00
Michael Zolotukhin b2738e41bf [LoopUnroll] Switch the default value of -unroll-runtime-epilog back to its original value.
As agreed in post-commit review of r265388, I'm switching the flag to
its original value until the 90% runtime performance regression on
SingleSource/Benchmarks/Stanford/Bubblesort is addressed.

llvm-svn: 277524
2016-08-02 21:24:14 +00:00
Daniel Berlin 26fcea91f6 Fixes for post-commit review comments on r277480
llvm-svn: 277510
2016-08-02 20:02:21 +00:00
Michael Zolotukhin d9b6ad3c01 [LoopUnroll] Ensure we create prolog loops in simplified form.
llvm-svn: 277502
2016-08-02 19:19:31 +00:00
Daniel Berlin de4be65313 MSVC 2013 does not implement C++11 unions properly, so remove the anoymous union for now,
and leave a FIXME.

llvm-svn: 277485
2016-08-02 16:59:51 +00:00
Daniel Berlin c43aa5a5b6 Rewrite the use optimizer to be less memory intensive and 50% faster.
Fixes PR28670

Summary:
Rewrite the use optimizer to be less memory intensive and 50% faster.
Fixes PR28670

The new use optimizer works like a standard SSA renaming pass, storing
all possible versions a MemorySSA use could get in a stack, and just
tracking indexes into the stack.
This uses much less memory than caching N^2 alias query results.
It's also a lot faster.

The current version defers phi node walking to the normal walker.

Reviewers: george.burgess.iv

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D23032

llvm-svn: 277480
2016-08-02 16:24:03 +00:00
Junmo Park db8f6eebee Minor code cleanups. NFC.
llvm-svn: 277415
2016-08-02 04:38:27 +00:00
Sean Silva f801575fd0 CodeExtractor : Add ability to preserve profile data.
Added ability to estimate the entry count of the extracted function and
the branch probabilities of the exit branches.

Patch by River Riddle!

Differential Revision: https://reviews.llvm.org/D22744

llvm-svn: 277411
2016-08-02 02:15:45 +00:00
James Molloy bade86cedc [SimplifyCFG] Fix nasty RAUW bug from r277325
Using RAUW was wrong here; if we have a switch transform such as:
  18 -> 6 then
  6 -> 0

If we use RAUW, while performing the second transform the  *transformed* 6
from the first will be also replaced, so we end up with:
  18 -> 0
  6 -> 0

Found by clang stage2 bootstrap; testcase added.

llvm-svn: 277332
2016-08-01 09:34:48 +00:00
James Molloy b2e436de42 [SimplifyCFG] Range reduce switches
If a switch is sparse and all the cases (once sorted) are in arithmetic progression, we can extract the common factor out of the switch and create a dense switch. For example:

    switch (i) {
    case 5: ...
    case 9: ...
    case 13: ...
    case 17: ...
    }

can become:

    if ( (i - 5) % 4 ) goto default;
    switch ((i - 5) / 4) {
    case 0: ...
    case 1: ...
    case 2: ...
    case 3: ...
    }

or even better:

   switch ( ROTR(i - 5, 2) {
   case 0: ...
   case 1: ...
   case 2: ...
   case 3: ...
   }

The division and remainder operations could be costly so we only do this if the factor is a power of two, and emit a right-rotate instead of a divide/remainder sequence. Dense switches can be lowered significantly better than sparse switches and can even be transformed into lookup tables.

llvm-svn: 277325
2016-08-01 07:45:11 +00:00
Sean Silva 423c7149dc Revert r277313 and r277314.
They seem to trigger an LSan failure:
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/15140/steps/check-llvm%20asan/logs/stdio

Revert "Add the tests for r277313"

This reverts commit r277314.

Revert "CodeExtractor : Add ability to preserve profile data."

This reverts commit r277313.

llvm-svn: 277317
2016-08-01 04:16:09 +00:00
Sean Silva a0a802abe3 Fix - CodeExtractor : Inherit Target Dependent Attributes from the parent function.
When extracting a set of blocks make sure to inherit all of the target
dependent attributes to make sure that the function will be valid for
lowering. One example is the "target-features" attribute for x86, if the
extracted region has functionality that relies on a specific feature it
will fail to be lowered.
This also allows for extracted functions to be valid for inlining, at
least back into the parent function, as the target attributes are tested
when inlining for compatibility.

Patch by River Riddle!

Differential Revision: https://reviews.llvm.org/D22713

llvm-svn: 277315
2016-08-01 03:15:32 +00:00
Sean Silva 6208924323 CodeExtractor : Add ability to preserve profile data.
Added ability to estimate the entry count of the extracted function and
the branch probabilities of the exit branches.

Patch by River Riddle!

Differential Revision: https://reviews.llvm.org/D22744

llvm-svn: 277313
2016-08-01 02:59:26 +00:00
Daniel Berlin 5130cc831a Fix the MemorySSA updating API to enable people to create memory accesses before removing old ones
llvm-svn: 277309
2016-07-31 21:08:20 +00:00
Adam Nemet 12937c361f [LoopUnroll] Include hotness of region in opt remark
LoopUnroll is a loop pass, so the analysis of OptimizationRemarkEmitter
is added to the common function analysis passes that loop passes
depend on.

The BFI and indirectly BPI used in this pass is computed lazily so no
overhead should be observed unless -pass-remarks-with-hotness is used.

This is how the patch affects the O3 pipeline:

         Dominator Tree Construction
         Natural Loop Information
         Canonicalize natural loops
         Loop-Closed SSA Form Pass
         Basic Alias Analysis (stateless AA impl)
         Function Alias Analysis Results
         Scalar Evolution Analysis
+        Lazy Branch Probability Analysis
+        Lazy Block Frequency Analysis
+        Optimization Remark Emitter
         Loop Pass Manager
           Rotate Loops
           Loop Invariant Code Motion
           Unswitch loops
         Simplify the CFG
         Dominator Tree Construction
         Basic Alias Analysis (stateless AA impl)
         Function Alias Analysis Results
         Combine redundant instructions
         Natural Loop Information
         Canonicalize natural loops
         Loop-Closed SSA Form Pass
         Scalar Evolution Analysis
+        Lazy Branch Probability Analysis
+        Lazy Block Frequency Analysis
+        Optimization Remark Emitter
         Loop Pass Manager
           Induction Variable Simplification
           Recognize loop idioms
           Delete dead loops
           Unroll loops
...

llvm-svn: 277203
2016-07-29 19:29:47 +00:00
Andrew Kaylor b99d1cc7ed Recommitting r275284: add support to inline __builtin_mempcpy
Patch by Sunita Marathe

Third try, now following fixes to MSan to handle mempcy in such a way that this commit won't break the MSan buildbots. (Thanks, Evegenii!)

llvm-svn: 277189
2016-07-29 18:23:18 +00:00
David Majnemer d536f2328e [ConstnatFolding] Teach the folder how to fold ConstantVector
A ConstantVector can have ConstantExpr operands and vice versa.
However, the folder had no ability to fold ConstantVectors which, in
some cases, was an optimization barrier.

Instead, rephrase the folder in terms of Constants instead of
ConstantExprs and teach callers how to deal with failure.

llvm-svn: 277099
2016-07-29 03:27:26 +00:00
Piotr Padlewski 84abc74f2c Added ThinLTO inlining statistics
Summary:
copypasta doc of ImportedFunctionsInliningStatistics class
 \brief Calculate and dump ThinLTO specific inliner stats.
 The main statistics are:
 (1) Number of inlined imported functions,
 (2) Number of imported functions inlined into importing module (indirect),
 (3) Number of non imported functions inlined into importing module
 (indirect).
 The difference between first and the second is that first stat counts
 all performed inlines on imported functions, but the second one only the
 functions that have been eventually inlined to a function in the importing
 module (by a chain of inlines). Because llvm uses bottom-up inliner, it is
 possible to e.g. import function `A`, `B` and then inline `B` to `A`,
 and after this `A` might be too big to be inlined into some other function
 that calls it. It calculates this statistic by building graph, where
 the nodes are functions, and edges are performed inlines and then by marking
 the edges starting from not imported function.

 If `Verbose` is set to true, then it also dumps statistics
 per each inlined function, sorted by the greatest inlines count like
 - number of performed inlines
 - number of performed inlines to importing module

Reviewers: eraman, tejohnson, mehdi_amini

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D22491

llvm-svn: 277089
2016-07-29 00:27:16 +00:00
Evgeniy Stepanov d240a889ad [sanitizer] Simplify and future-proof maybeMarkSanitizerLibraryCallNoBuiltin().
Sanitizers set nobuiltin attribute on certain library functions to
avoid a situation where such function is neither instrumented nor
intercepted.

At the moment the list of interesting functions is hardcoded. This
change replaces it with logic based on
TargetLibraryInfo::hasOptimizedCodegen and the presense of readnone
function attribute (sanitizers are generally interested in memory
behavior of library functions).

This is expected to be a no-op change: the new logic matches exactly
the same set of functions.

r276771 (currently reverted) added mempcpy() to the list, breaking
MSan tests. With this change, r276771 can be safely re-landed.

llvm-svn: 277086
2016-07-28 23:45:15 +00:00
Michael Zolotukhin ff5ce639de Add verifyAnalysis for LCSSA.
Summary:
LCSSAWrapperPass currently doesn't override verifyAnalysis method, so pass
manager doesn't verify LCSSA. This patch adds the method so that we start
verifying LCSSA between loop passes.

Reviewers: chandlerc, sanjoy, hfinkel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D22888

llvm-svn: 276941
2016-07-27 23:35:53 +00:00
Sean Silva 285e0974f0 Refactor - CodeExtractor : Move check for valid block to static utility
This lets you actually check to see if a block is valid before trying to
extract.

Patch by River Riddle!

Differential Revision: https://reviews.llvm.org/D22699

llvm-svn: 276846
2016-07-27 08:02:46 +00:00
Andrew Kaylor f990fa5f7b Reverting r276771 due to MSan failures.
llvm-svn: 276824
2016-07-27 01:19:24 +00:00
Adam Nemet 2f2bd8caf4 [LoopUtils] Sort headers
llvm-svn: 276776
2016-07-26 17:52:02 +00:00
Andrew Kaylor 3104a6bad0 Re-committing r275284: add support to inline __builtin_mempcpy
Patch by Sunita Marathe

Differential Revision: http://reviews.llvm.org/D21920

llvm-svn: 276771
2016-07-26 17:23:13 +00:00
Michael Kuperstein 39feb6290c [PM] Port SymbolRewriter to the new PM
Differential Revision: https://reviews.llvm.org/D22703

llvm-svn: 276687
2016-07-25 20:52:00 +00:00
Michael Kuperstein 9a89b15aa2 Attempt to pacify windows bots.
llvm-svn: 276672
2016-07-25 18:39:08 +00:00
Michael Kuperstein 8f8e1d1bf6 Don't use iplist in SymbolRewriter. NFC.
There didn't appear to be a good reason to use iplist in this case, a regular
list of unique_ptr works just as well.
Change made in preparation to a new PM port (since iplist is not moveable).

llvm-svn: 276668
2016-07-25 18:10:54 +00:00
David Majnemer 6f014d37d5 [Utils] Simplify combineMetadata
Use a range-based for loop, no functional change is intended.

llvm-svn: 276600
2016-07-25 02:21:19 +00:00
Elena Demikhovsky 376a18bd92 [Loop Vectorizer] Handling loops FP induction variables.
Allowed loop vectorization with secondary FP IVs. Like this:
float *A;
float x = init;
for (int i=0; i < N; ++i) {
  A[i] = x;
  x -= fp_inc;
}

The auto-vectorization is possible when the induction binary operator is "fast" or the function has "unsafe" attribute.

Differential Revision: https://reviews.llvm.org/D21330

llvm-svn: 276554
2016-07-24 07:24:54 +00:00
George Burgess IV 93ea19b9a6 [MSSA] Make EXPENSIVE_CHECKS check more.
checkClobberSanity will now be run for all results of `ClobberWalk`,
instead of just the crazy phi-optimized ones. This can help us catch
cases where our cache is being wonky.

llvm-svn: 276553
2016-07-24 07:03:49 +00:00
George Burgess IV f23eb70e03 [MSSA] Remove useless assert. NFC.
liveOnEntry is always a MemoryDef; asserting that a MemoryPhi isn't
liveOnEntry, while correct, isn't very helpful. :)

llvm-svn: 276542
2016-07-24 01:50:07 +00:00
Sean Silva ab6a683765 Avoid using a raw AssumptionCacheTracker in various inliner functions.
This unblocks the new PM part of River's patch in
https://reviews.llvm.org/D22706

Conveniently, this same change was needed for D21921 and so these
changes are just spun out from there.

llvm-svn: 276515
2016-07-23 04:22:50 +00:00
Wei Mi e04d0eff29 [PM] Port BreakCriticalEdges to the new PM.
Differential Revision: https://reviews.llvm.org/D22688

llvm-svn: 276449
2016-07-22 18:04:25 +00:00
George Burgess IV 400ae40348 [MSSA] Add an overload for getClobberingMemoryAccess.
A seemingly common use for the walker's getClobberingMemoryAccess
function is:

```
MemoryAccess *getClobber(MemorySSAWalker *W, MemoryUseOrDef *MUD) {
  const Instruction *I = MUD->getMemoryInst();
  return W->getClobberingMemoryAccess(I);
}
```

Which is kind of redundant, since walkers will ultimately query MSSA to
find out which MemoryAccess `I` maps to (...which is always `MUD`).

So, this patch adds an overload of getClobberingMemoryAccess that
accepts MemoryAccesses directly. As a result, the Instruction overload
of getClobberingMemoryAccess becomes a lightweight wrapper around our
new overload.

Additionally, this patch un`virtual`izes the Instruction overload of
getClobberingMemoryAccess, since there doesn't seem to be a walker that
benefits from that being virtual, and I can't think of how else one
would implement it. Happy to make it virtual again if we would benefit
from doing so.

llvm-svn: 276169
2016-07-20 19:51:34 +00:00
Sanjay Patel 683170bf56 move decomposeBitTestICmp() to Transforms/Utils; NFC
As noted in https://reviews.llvm.org/D22537 , we can use this functionality in 
visitSelectInstWithICmp() and InstSimplify, but currently we have duplicated
code.

llvm-svn: 276140
2016-07-20 17:18:45 +00:00
Sanjay Patel be53c65fab fix documentation comments; NFC
llvm-svn: 276135
2016-07-20 16:30:55 +00:00
Michael Zolotukhin 6bc56d552a Revert "Revert r275883 and r275891. They seem to cause PR28608."
This reverts commit r276064, and thus reapplies r275891 and r275883 with
a fix for PR28608.

llvm-svn: 276077
2016-07-20 01:55:27 +00:00
Sean Silva 554efb28d2 Revert r275883 and r275891. They seem to cause PR28608.
Revert "[LoopSimplify] Update LCSSA after separating nested loops."

This reverts commit r275891.

Revert "[LCSSA] Post-process PHI-nodes created by SSAUpdate when constructing LCSSA form."

This reverts commit r275883.

llvm-svn: 276064
2016-07-19 23:54:29 +00:00
Daniel Berlin 1986030b62 Fix unused variable
llvm-svn: 276050
2016-07-19 23:08:08 +00:00
Daniel Berlin 5c46b943db Make MemorySSA::dominates/locallydominates constant time
Summary: Make MemorySSA::dominates/locallydominates constant time

Reviewers: george.burgess.iv, gberry

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D22527

llvm-svn: 276046
2016-07-19 22:49:43 +00:00
George Burgess IV 5f30897b7b [MemorySSA] Update to the new shiny walker.
This patch updates MemorySSA's use-optimizing walker to be more
accurate and, in some cases, faster.

Essentially, this changed our core walking algorithm from a
cache-as-you-go DFS to an iteratively expanded DFS, with all of the
caching happening at the end. Said expansion happens when we hit a Phi,
P; we'll try to do the smallest amount of work possible to see if
optimizing above that Phi is legal in the first place. If so, we'll
expand the search to see if we can optimize to the next phi, etc.

An iteratively expanded DFS lets us potentially quit earlier (because we
don't assume that we can optimize above all phis) than our old walker.
Additionally, because we don't cache as we go, we can now optimize above
loops.

As an added bonus, this patch adds a ton of verification (if
EXPENSIVE_CHECKS are enabled), so finding bugs is easier.

Differential Revision: https://reviews.llvm.org/D21777

llvm-svn: 275940
2016-07-19 01:29:15 +00:00
Michael Zolotukhin ea5b72825b [LoopSimplify] Update LCSSA after separating nested loops.
Summary:
Usually LCSSA survives this transformation, but in some cases (see
attached test) it doesn't: values from the original loop after
separating might be used from the outer loop. Before the transformation
it was the same loop, so LCSSA phis were not required.

This fixes PR28272.

Reviewers: sanjoy, hfinkel, chandlerc

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D21665

llvm-svn: 275891
2016-07-18 19:44:19 +00:00
Michael Zolotukhin 7a3040dc83 [LCSSA] Post-process PHI-nodes created by SSAUpdate when constructing LCSSA form.
Summary:
SSAUpdate might insert PHI-nodes inside loops, which can break LCSSA
form unless we fix it up.

This fixes PR28424.

Reviewers: sanjoy, chandlerc, hfinkel

Subscribers: uabelho, llvm-commits

Differential Revision: http://reviews.llvm.org/D21997

llvm-svn: 275883
2016-07-18 19:05:08 +00:00
Michael Zolotukhin a78937afb2 Make processInstruction from LCSSA.cpp externally available.
Summary:
When a pass tries to keep LCSSA form it's often convenient to be able to update
LCSSA for a set of instructions rather than for the entire loop. This patch makes the
processInstruction from LCSSA externally available under a name
formLCSSAForInstruction.

Reviewers: chandlerc, sanjoy, hfinkel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D22378

llvm-svn: 275613
2016-07-15 21:08:41 +00:00
David Majnemer a940f360cb [AliasAnalysis] Give back AA results for fence instructions
Calling getModRefInfo with a fence resulted in crashes because fences
don't have a memory location.  Add a new predicate to Instruction
called isFenceLike which indicates that the instruction mutates memory
but not any single memory location in particular. In practice, it is a
proxy for the set of instructions which "mayWriteToMemory" but cannot be
used with MemoryLocation::get.

This fixes PR28570.

llvm-svn: 275581
2016-07-15 17:19:24 +00:00
Andrew Kaylor 346dd7f1bd Reverting r275284 due to platform-specific test failures
llvm-svn: 275304
2016-07-13 19:09:16 +00:00
Andrew Kaylor 12cccdd731 Fix for Bug 26903, adds support to inline __builtin_mempcpy
Patch by Sunita Marathe

Differential Revision: http://reviews.llvm.org/D21920

llvm-svn: 275284
2016-07-13 17:25:11 +00:00
Davide Italiano 081fd139b3 [LoopSimplify] Remove a comment which is unlikely to age well.
Chandler pointed out in his review but I forgot to remove before
committing, my bad.

llvm-svn: 274963
2016-07-09 03:27:24 +00:00
Davide Italiano cd96cfd8df [PM] Port LoopSimplify to the new pass manager.
While here move simplifyLoop() function to the new header, as
suggested by Chandler in the review.

Differential Revision:  http://reviews.llvm.org/D21404

llvm-svn: 274959
2016-07-09 03:03:01 +00:00
Xinliang David Li 7853c1dd73 Rename LoopAccessAnalysis to LoopAccessLegacyAnalysis /NFC
llvm-svn: 274927
2016-07-08 20:55:26 +00:00
Davide Italiano 16284df8ec [PM] Port InstSimplify to the new pass manager.
llvm-svn: 274796
2016-07-07 21:14:36 +00:00
Sjoerd Meijer 7435a910b5 Addressing post-commit comments for not rewriting fputs:
moved the optimise for size check inside function optimizeFPuts.

llvm-svn: 274758
2016-07-07 14:31:19 +00:00
Sjoerd Meijer 17c08dc701 Code size optimisation: don't rewrite fputs to fwrite when optimising for size
because fwrite requires more arguments and thus extra MOVs are required.

llvm-svn: 274753
2016-07-07 13:56:23 +00:00
Chad Rosier 232e29ebea [MemorySSA] Reinstate the legacy printer and verifier.
Differential Revision: http://reviews.llvm.org/D22058

llvm-svn: 274679
2016-07-06 21:20:47 +00:00
Daniel Berlin fc7e651bfd Fix handling of forward unreachable but reverse-reachable blocks in MemorySSA construction
llvm-svn: 274606
2016-07-06 05:32:05 +00:00
George Burgess IV a362b09a81 [MSSA] Fix typo. NFC.
llvm-svn: 274590
2016-07-06 00:28:43 +00:00
Xinliang David Li 94734eef33 [PM] refactor LoopAccessInfo code part-2
Differential Revision: http://reviews.llvm.org/D21636

llvm-svn: 274334
2016-07-01 05:59:55 +00:00
Michael Kuperstein 835facd863 [PM] Normalize FIXMEs for missing PreserveCFG to have the same wording.
llvm-svn: 273974
2016-06-28 00:54:12 +00:00
Daniel Berlin 16ed57c86b Factor out buildMemorySSA from getWalker.
NFC.

llvm-svn: 273901
2016-06-27 18:22:27 +00:00
Benjamin Kramer 706e48839d [CodeExtractor] Merge DEBUG statements in an attempt to fix the msvc
build.

There's a known bug in msvc 2013 that fails to compile do-while loops
inside of ranged for loops.

llvm-svn: 273811
2016-06-26 13:39:33 +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 9f506259c8 Just a small cleanup
No functional change is intended

llvm-svn: 273780
2016-06-25 08:34:38 +00:00
David Majnemer e14e7bc4b8 Revert "[SimplifyCFG] Stop inserting calls to llvm.trap for UB"
This reverts commit r273778, it seems to break UBSan :/

llvm-svn: 273779
2016-06-25 08:19:55 +00:00
David Majnemer d346a37737 [SimplifyCFG] Stop inserting calls to llvm.trap for UB
SimplifyCFG had logic to insert calls to llvm.trap for two very
particular IR patterns: stores and invokes of undef/null.

While InstCombine canonicalizes certain undefined behavior IR patterns
to stores of undef, phase ordering means that this cannot be relied upon
in general.

There are much better tools than llvm.trap: UBSan and ASan.

N.B. I could be argued into reverting this change if a clear argument as
to why it is important that we synthesize llvm.trap for stores, I'd be
hard pressed to see why it'd be useful for invokes...

llvm-svn: 273778
2016-06-25 08:04:19 +00:00
David Majnemer 1fea77c6fc [SimplifyCFG] Replace calls to null/undef with unreachable
Calling null is undefined behavior, a call to undef can be trivially
treated as a call to null.

llvm-svn: 273776
2016-06-25 07:37:27 +00:00
Michael Kuperstein f4c56e97df It isn't meaningful for a transform to preserve another transform. NFC.
llvm-svn: 273761
2016-06-25 00:47:21 +00:00
David Majnemer b8da3a2bb2 Reinstate r273711
r273711 was reverted by r273743.  The inliner needs to know about any
call sites in the inlined function.  These were obscured if we replaced
a call to undef with an undef but kept the call around.

This fixes PR28298.

llvm-svn: 273753
2016-06-25 00:04:10 +00:00
David Majnemer 580e754348 Silence a -Wsign-compare warning
llvm-svn: 273752
2016-06-25 00:04:06 +00:00
Nico Weber ae2ef4ccd4 Revert r273711, it caused PR28298.
llvm-svn: 273743
2016-06-24 22:52:39 +00:00
George Burgess IV fd1f2f8561 [MemorySSA] Move code around a bit. NFC.
This patch moves MSSA's caching walker into MemorySSA, and moves the
actual definition of MSSA's caching walker out of MemorySSA.h. This is
done in preparation for the new walker, which should be out for review
soonish.

Also, this patch removes a field from UpwardsMemoryQuery and has a few
lines of diff from clang-format'ing MemorySSA.cpp.

llvm-svn: 273723
2016-06-24 21:02:12 +00:00
David Majnemer 3b3e954ea2 SimplifyInstruction does not imply DCE
We cannot remove an instruction with no uses just because
SimplifyInstruction succeeds.  It may have side effects.

llvm-svn: 273711
2016-06-24 19:34:46 +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
Chuang-Yu Cheng 68f7f1cf00 Teaching SimplifyCFG to recognize the Or-Mask trick that InstCombine uses to
reduce the number of comparisons.

Specifically, InstCombine can turn:
  (i == 5334 || i == 5335)
into:
  ((i | 1) == 5335)

SimplifyCFG was already able to detect the pattern:
  (i == 5334 || i == 5335)
to:
  ((i & -2) == 5334)

This patch supersedes D21315 and resolves PR27555
(https://llvm.org/bugs/show_bug.cgi?id=27555).

Thanks to David and Chandler for the suggestions!

Author: Thomas Jablin (tjablin)
Reviewers: majnemer chandlerc halfdan cycheng

http://reviews.llvm.org/D21397

llvm-svn: 273639
2016-06-24 01:59:00 +00:00
Rafael Espindola 2b7fef681f Delete more dead code.
Found by gcc 6.

llvm-svn: 273402
2016-06-22 12:44:16 +00:00
Daniel Berlin 1430026142 Add MemoryAccess creation and PHI creation APIs to MemorySSA
Reviewers: george.burgess.iv, gberry, hfinkel

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D21463

llvm-svn: 273295
2016-06-21 18:39:20 +00:00
Daniel Berlin ada263dcd0 Rename to be consistent with other type names. NFC
llvm-svn: 273194
2016-06-20 20:21:33 +00:00
Marcin Koscielnicki 3feda222c6 [sanitizers] Disable target-specific lowering of string functions.
CodeGen has hooks that allow targets to emit specialized code instead
of calls to memcmp, memchr, strcpy, stpcpy, strcmp, strlen, strnlen.
When ASan/MSan/TSan/ESan is in use, this sidesteps its interceptors, resulting
in uninstrumented memory accesses.  To avoid that, make these sanitizers
mark the calls as nobuiltin.

Differential Revision: http://reviews.llvm.org/D19781

llvm-svn: 273083
2016-06-18 10:10:37 +00:00
Chuang-Yu Cheng 5078f94690 Use m_APInt in SimplifyCFG
Switch from m_Constant to m_APInt per David's request. NFC.

Author: Thomas Jablin (tjablin)
Reviewers: majnemer cycheng

http://reviews.llvm.org/D21440

llvm-svn: 272977
2016-06-17 00:04:39 +00:00
Evgeniy Stepanov 72d961a1da [safestack] Fixup llvm.dbg.value when rewriting unsafe allocas.
When moving unsafe allocas to the unsafe stack, dbg.declare intrinsics are
updated to refer to the new location.

This change does the same to dbg.value intrinsics.

llvm-svn: 272968
2016-06-16 22:34:00 +00:00
Igor Laevsky 87f0d0e185 Revert r272891 "[JumpThreading] Prevent dangling pointer problems in BranchProbabilityInfo"
It was causing failures in Profile-i386 and Profile-x86_64 tests.

llvm-svn: 272912
2016-06-16 16:25:53 +00:00
Igor Laevsky c9179fd2c2 [JumpThreading] Prevent dangling pointer problems in BranchProbabilityInfo
We should update results of the BranchProbabilityInfo after removing block in JumpThreading. Otherwise 
we will get dangling pointer inside BranchProbabilityInfo cache.

Differential Revision: http://reviews.llvm.org/D20957

llvm-svn: 272891
2016-06-16 13:28:25 +00:00
Adam Nemet bdbc5227ce [LAA] Default getInfo to not speculate symbolic strides. NFC
Soon we won't be passing Strides to getInfo and then we'll have fewer
call sites to update.

llvm-svn: 272878
2016-06-16 08:26:56 +00:00
Chuang-Yu Cheng dbe00d51b4 SimplifyCFG is able to detect the pattern:
(i == 5334 || i == 5335)
to:
    ((i & -2) == 5334)

This transformation has some incorrect side conditions. Specifically, the
transformation is only applied when the right-hand side constant (5334 in
the example) is a power of two not equal and not equal to the negated mask.
These side conditions were added in r258904 to fix PR26323. The correct side
condition is that: ((Constant & Mask) == Constant)[(5334 & -2) == 5334].

It's a little bit hard to see why these transformations are correct and what
the side conditions ought to be. Here is a CVC3 program to verify them for
64-bit values:
    ONE  : BITVECTOR(64) = BVZEROEXTEND(0bin1, 63);
    x    : BITVECTOR(64);
    y    : BITVECTOR(64);
    z    : BITVECTOR(64);
    mask : BITVECTOR(64) = BVSHL(ONE, z);
    QUERY( (y & ~mask = y) =>
           ((x & ~mask = y) <=> (x = y OR x = (y |  mask)))
    );

Please note that each pattern must be a dual implication (<--> or iff). One
directional implication can create spurious matches. If the implication is
only one-way, an unsatisfiable condition on the left side can imply a
satisfiable condition on the right side. Dual implication ensures that
satisfiable conditions are transformed to other satisfiable conditions and
unsatisfiable conditions are transformed to other unsatisfiable conditions.

Here is a concrete example of a unsatisfiable condition on the left
implying a satisfiable condition on the right:
    mask = (1 << z)
    (x & ~mask) == y --> (x == y || x == (y | mask))

Substituting y = 3, z = 0 yields:
    (x & -2) == 3 --> (x == 3 || x == 2)

The version of this code before r258904 had no side-conditions and
incorrectly justified itself in comments through one-directional
implication.

Thanks to Chandler for the suggestion!

Author: Thomas Jablin (tjablin)
Reviewers: chandlerc majnemer hfinkel cycheng

http://reviews.llvm.org/D21417

llvm-svn: 272873
2016-06-16 04:44:25 +00:00
Xinliang David Li 1e16d61f1f Address review feedbacks of AddDiscriminator change
llvm-svn: 272850
2016-06-15 22:20:56 +00:00
Xinliang David Li 1eaecefaf9 [PM] Port Add discriminator pass to new PM
llvm-svn: 272847
2016-06-15 21:51:30 +00:00
Davide Italiano 9d305d707e [LoopSimplify] Analyses do not need to be member variables.
In preparation for porting this pass to the new PM.

llvm-svn: 272818
2016-06-15 18:51:25 +00:00
Geoff Berry efb0dd176a [MemorySSA] Set CFGOnly correctly for MemorySSAWrapperPass
Subscribers: mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D21344

llvm-svn: 272712
2016-06-14 21:19:40 +00:00
Peter Collingbourne 96efdd6107 IR: Introduce local_unnamed_addr attribute.
If a local_unnamed_addr attribute is attached to a global, the address
is known to be insignificant within the module. It is distinct from the
existing unnamed_addr attribute in that it only describes a local property
of the module rather than a global property of the symbol.

This attribute is intended to be used by the code generator and LTO to allow
the linker to decide whether the global needs to be in the symbol table. It is
possible to exclude a global from the symbol table if three things are true:
- This attribute is present on every instance of the global (which means that
  the normal rule that the global must have a unique address can be broken without
  being observable by the program by performing comparisons against the global's
  address)
- The global has linkonce_odr linkage (which means that each linkage unit must have
  its own copy of the global if it requires one, and the copy in each linkage unit
  must be the same)
- It is a constant or a function (which means that the program cannot observe that
  the unique-address rule has been broken by writing to the global)

Although this attribute could in principle be computed from the module
contents, LTO clients (i.e. linkers) will normally need to be able to compute
this property as part of symbol resolution, and it would be inefficient to
materialize every module just to compute it.

See:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160509/356401.html
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160516/356738.html
for earlier discussion.

Part of the fix for PR27553.

Differential Revision: http://reviews.llvm.org/D20348

llvm-svn: 272709
2016-06-14 21:01:22 +00:00
Adam Nemet 57fb8989a5 [LoopVer] Remove an assert that's redundant now. NFC
Ensuring that the PHI are all single-operand is not performed in the
second pass added by the previous pass.  This removes the assert from
the first pass.

llvm-svn: 272650
2016-06-14 09:39:01 +00:00
Adam Nemet 73a26957fc [LoopVer] Update all existing PHIs in the exit block
We only used to add the edge from the cloned loop to PHIs that
corresponded to values defined by the loop.  We need to do this for all
PHIs obviously since we need a PHI operand for each incoming edge.

This includes things like PHIs with a constant value or with values
defined before the original loop (see the testcases).

After the patch the PHIs are added to the exit block in two passes.

In the first pass we ensure there is a single-operand (LCSSA) PHI for
each value defined by the loop.

In the second pass we loop through each (single-operand) PHI and add the
value for the edge from the cloned loop.  If the value is defined in the
loop we'll use the cloned instruction from the cloned loop.

Fixes PR28037

llvm-svn: 272649
2016-06-14 09:38:54 +00:00
Davide Italiano cccf4f01ad [PM] Port Mem2Reg to the new pass manager.
llvm-svn: 272630
2016-06-14 03:22:22 +00:00
Vikram TV 299abc10e7 Fix a typo in loop versioning.
Reviewers: ashutosh.nema

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D21281

llvm-svn: 272545
2016-06-13 10:49:28 +00:00
Benjamin Kramer 4ca41fd09e Run clang-tidy's performance-unnecessary-copy-initialization over LLVM.
No functionality change intended.

llvm-svn: 272516
2016-06-12 17:30:47 +00:00
Benjamin Kramer d3f4c05aea Move instances of std::function.
Or replace with llvm::function_ref if it's never stored. NFC intended.

llvm-svn: 272513
2016-06-12 16:13:55 +00:00
Benjamin Kramer bdc4956bac Pass DebugLoc and SDLoc by const ref.
This used to be free, copying and moving DebugLocs became expensive
after the metadata rewrite. Passing by reference eliminates a ton of
track/untrack operations. No functionality change intended.

llvm-svn: 272512
2016-06-12 15:39:02 +00:00
Eli Friedman f1da33e4d3 [LICM] Make isGuaranteedToExecute more accurate.
Summary:
Make isGuaranteedToExecute use the
isGuaranteedToTransferExecutionToSuccessor helper, and make that helper
a bit more accurate.

There's a potential performance impact here from assuming that arbitrary
calls might not return. This probably has little impact on loads and
stores to a pointer because most things alias analysis can reason about
are dereferenceable anyway. The other impacts, like less aggressive
hoisting of sdiv by a variable and less aggressive hoisting around
volatile memory operations, are unlikely to matter for real code.

This also impacts SCEV, which uses the same helper.  It's a minor
improvement there because we can tell that, for example, memcpy always
returns normally. Strictly speaking, it's also introducing
a bug, but it's not any worse than everywhere else we assume readonly
functions terminate.

Fixes http://llvm.org/PR27857.

Reviewers: hfinkel, reames, chandlerc, sanjoy

Subscribers: broune, llvm-commits

Differential Revision: http://reviews.llvm.org/D21167

llvm-svn: 272489
2016-06-11 21:48:25 +00:00
Vikram TV c702b8b3d7 Delay dominator updation while cloning loop.
Summary:
Dominator updation fails for a loop inserted with a new basicblock.

A block required by DT to set the IDom might not have been cloned yet. This is because there is no predefined ordering of loop blocks (except for the header block which should be the first block in the list).

The patch first creates DT nodes for the cloned blocks and then separately updates the DT in a follow-on loop.

Reviewers: anemet, dberlin

Subscribers: dberlin, llvm-commits

Differential Revision: http://reviews.llvm.org/D20899

llvm-svn: 272479
2016-06-11 16:41:10 +00:00
Sebastian Pop e1f60b1fb3 MemorySSA: fix memory access local dominance function for live on entry
A memory access defined on function entry cannot be locally dominated by another memory access.
The patch was split from http://reviews.llvm.org/D19338 which exposes the problem.

Differential Revision: http://reviews.llvm.org/D21039

llvm-svn: 272436
2016-06-10 21:36:41 +00:00
Evgeniy Stepanov 122f984a33 Move isGuaranteedToExecute out of LICM.
Also rename LICMSafetyInfo to LoopSafetyInfo.
Both will be used in LoopUnswitch in a separate change.

llvm-svn: 272420
2016-06-10 20:03:17 +00:00
Easwaran Raman e12c487b8c [PM] Port LCSSA to the new PM.
Differential Revision: http://reviews.llvm.org/D21090

llvm-svn: 272294
2016-06-09 19:44:46 +00:00
Xinliang David Li ecde1c7f3d Revert r272194 No need for it if loop Analysis Manager is used
llvm-svn: 272243
2016-06-09 03:22:39 +00:00
Michael Zolotukhin 8e7e76729d [LoopSimplify] Preserve LCSSA when merging exit blocks.
Summary:
This fixes PR26682. Also add LCSSA as a preserved pass to LoopSimplify,
that looks correct to me and allows to write a test for the issue.

Reviewers: chandlerc, bogner, sanjoy

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D21112

llvm-svn: 272224
2016-06-08 23:13:21 +00:00
Michael Zolotukhin aa547616d2 [LoopUnroll] Check that DT is available before trying to verify it.
llvm-svn: 272221
2016-06-08 22:49:59 +00:00
Xinliang David Li 572135f717 [PM] Refector LoopAccessInfo analysis code
This is the preparation patch to port the analysis to new PM

Differential Revision: http://reviews.llvm.org/D20560

llvm-svn: 272194
2016-06-08 20:15:37 +00:00
Davide Italiano 2d5ab0a56a [PM] LoopSimplify. Remove unneeded pass dependencies. NFCI.
llvm-svn: 272140
2016-06-08 13:56:59 +00:00
Sanjoy Das f90e28d6fd [IndVars] Remove -liv-reduce
It is an off-by-default option that no one seems to use[0], and given
that SCEV directly understands the overflow instrinsics there is no real
need for it anymore.

[0]: http://lists.llvm.org/pipermail/llvm-dev/2016-April/098181.html

llvm-svn: 271845
2016-06-05 18:01:12 +00:00
David Majnemer 2482e1c017 [SimplifyCFG] Don't kill empty cleanuppads with multiple uses
A basic block could contain:
  %cp = cleanuppad []
  cleanupret from %cp unwind to caller

This basic block is empty and is thus a candidate for removal.  However,
there can be other uses of %cp outside of this basic block.  This is
only possible in unreachable blocks.

Make our transform more correct by checking that the pad has a single
user before removing the BB.

This fixes PR28005.

llvm-svn: 271816
2016-06-04 23:50:03 +00:00
Geoff Berry b96d3b2dd8 [MemorySSA] Port to new pass manager
Add support for the new pass manager to MemorySSA pass.

Change MemorySSA to be computed eagerly upon construction.

Change MemorySSAWalker to be owned by the MemorySSA object that creates
it.

Reviewers: dberlin, george.burgess.iv

Subscribers: mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D19664

llvm-svn: 271432
2016-06-01 21:30:40 +00:00
Peter Collingbourne 382d81cacf IR: Allow multiple global metadata attachments with the same type.
This will be necessary to allow the global merge pass to attach
multiple debug info metadata nodes to global variables once we reverse
the edge from DIGlobalVariable to GlobalVariable.

Differential Revision: http://reviews.llvm.org/D20414

llvm-svn: 271358
2016-06-01 01:17:57 +00:00
Benjamin Kramer 728f4448a9 Remove some 'const' specifiers that do nothing but prevent moving the argument.
Found by clang-tidy's misc-move-const-arg. While there drop some
obsolete c_str() calls.

llvm-svn: 271181
2016-05-29 10:46:35 +00:00
Sanjoy Das ae09b3cd4c [IndVars] Eliminate op.with.overflow when possible (re-apply)
Summary:
If we can prove that an op.with.overflow intrinsic does not overflow, we
can get rid of the intrinsic, and replace it with non-wrapping
arithmetic.

This was first checked in at r265913 but reverted in r265950 because it
exposed some issues around how SCEV handled post-inc add recurrences.
Those issues have now been fixed.

Reviewers: atrick, regehr

Subscribers: sanjoy, mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D18685

llvm-svn: 271153
2016-05-29 00:36:25 +00:00
Mehdi Amini bcc47419d9 ValueMapper: fix assertion when null-mapping a constant for linking metadata
Summary:
When RF_NullMapMissingGlobalValues is set, mapValue can return null
for GlobalValue. When mapping the operands of a constant that is
referenced from metadata, we need to handle this case and actually
return null instead of mapping this constant.

Reviewers: dexonsmith, rafael

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D20713

llvm-svn: 271129
2016-05-28 17:26:03 +00:00
Evgeny Stupachenko ea2aef4a1d The patch refactors unroll pass.
Summary:
Unroll factor (Count) calculations moved to a new function.
Early exits on pragma and "-unroll-count" defined factor added.
New type of unrolling "Force" introduced (previously used implicitly).
New unroll preference "AllowRemainder" introduced and set "true" by default.
(should be set to false for architectures that suffers from it).

Reviewers: hfinkel, mzolotukhin, zzheng

Differential Revision: http://reviews.llvm.org/D19553

From: Evgeny Stupachenko <evstupac@gmail.com>
llvm-svn: 271071
2016-05-27 23:15:06 +00:00
Davide Italiano 88a7892a07 [LCSSA] Simplify. Suggested by Sanjoy.
llvm-svn: 271041
2016-05-27 20:25:31 +00:00
Tim Northover 10a1e8b1fe Vectorizer: track non-fast FP instructions through phis when finding reductions.
When we traced through a phi node looking for floating-point reductions, we
forgot whether we'd ever seen an instruction without fast-math flags (that
would block vectorization). This propagates it through to the end.

llvm-svn: 271015
2016-05-27 16:40:27 +00:00
Benjamin Kramer 4fed928f53 Avoid some copies by using const references.
clang-tidy's performance-unnecessary-copy-initialization with some manual
fixes. No functional changes intended.

llvm-svn: 270988
2016-05-27 12:30:51 +00:00
Mehdi Amini 9ee054aea8 ValueMapper: fix typo in minor optimization on constant mapping (NFC)
If every operands of a constant are mapping to themselves, and the
type does not change, we have an early exit as acknowledged in the
comment:

  // Otherwise, we have some other constant to remap.  Start by checking to see
  // if all operands have an identity remapping.

However instead of checking for identity the code was checking if the
operands were mapped to the constant itself, which is rarely true.

As a consequence, the coverage report showed that the early exit was
never taken.

llvm-svn: 270944
2016-05-27 00:32:12 +00:00
Chad Rosier e5819e2732 [InstCombine] Catch more bswap cases missed due to zext and truncs.
Fixes PR27824.
Differential Revision: http://reviews.llvm.org/D20591.

llvm-svn: 270853
2016-05-26 14:58:51 +00:00
Peter Collingbourne b9aa1f4a03 MemorySSA: Revert r269678 and r268068; replace with special casing in MemorySSA.
It turns out that too many passes are relying on alias analysis results
for control dependencies. Until we fix that by introducing a more accurate
modelling of control dependencies, special case assume in MemorySSA instead.

Also introduce tests to ensure we don't regress the FunctionAttrs or LICM
passes.

Differential Revision: http://reviews.llvm.org/D20658

llvm-svn: 270823
2016-05-26 04:58:46 +00:00
Peter Collingbourne ffecb1441b MemorySSA: Remove argument to createNewAccess function.
There is only one caller of MemorySSA::createNewAccess, and it passes true
as the IgnoreNonMemory argument. Remove that argument and fold its behavior
into createNewAccess.

llvm-svn: 270812
2016-05-26 01:19:17 +00:00
Mehdi Amini cc8c107e6a ValueMaterializer: rename materializeDeclFor() to materialize()
It may materialize a declaration, or a definition. The name could
be misleading. This is following a merge of materializeInitFor()
into materializeDeclFor().

Differential Revision: http://reviews.llvm.org/D20593

llvm-svn: 270759
2016-05-25 21:03:21 +00:00
Mehdi Amini 53a6672e21 ValueMaterializer: fuse materializeDeclFor and materializeInitFor (NFC)
They were originally separated to handle the co-recursion between
the ValueMapper and the ValueMaterializer. This recursion does not
exist anymore: the ValueMapper now uses a Worklist and the
ValueMaterializer is scheduling job on the Worklist.

Differential Revision: http://reviews.llvm.org/D20593

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 270758
2016-05-25 21:01:51 +00:00
Chad Rosier a00df49dc5 Clarify that we match BSwap in InstCombine and BitReverse in CGP. NFC.
Also, rename recognizeBitReverseOrBSwapIdiom to recognizeBSwapOrBitReverseIdiom,
so the ordering of the MatchBSwaps and MatchBitReversals arguments are
consistent with the function name.

llvm-svn: 270715
2016-05-25 16:22:14 +00:00
Chad Rosier 56def258e3 Fix 80-column violation.
llvm-svn: 270329
2016-05-21 21:12:06 +00:00
David Majnemer 9f92f4c497 [SimplifyCFG] Remove cleanuppads which are empty except for calls to lifetime.end
A cleanuppad is not cheap, they turn into many instructions and result
in additional spills and fills.  It is not worth keeping a cleanuppad
around if all it does is hold a lifetime.end instruction.

N.B.  We first try to merge the cleanuppad with another cleanuppad to
avoid dropping the lifetime and debug info markers.

llvm-svn: 270314
2016-05-21 05:12:32 +00:00
Sanjay Patel 75892a1543 [SimplifyCFG] eliminate switch cases based on known range of switch condition
This was noted in PR24766:
https://llvm.org/bugs/show_bug.cgi?id=24766#c2

We may not know whether the sign bit(s) are zero or one, but we can still
optimize based on knowing that the sign bit is repeated.

Differential Revision: http://reviews.llvm.org/D20275

llvm-svn: 270222
2016-05-20 14:53:09 +00:00
Dehao Chen f16376b505 Follow-up patch of http://reviews.llvm.org/D19948 to handle missing profiles when simplifying CFG.
Summary: Set default branch weight to 1:1 if one of the branch has profile missing when simplifying CFG.

Reviewers: spatel, davidxl

Subscribers: danielcdh, llvm-commits

Differential Revision: http://reviews.llvm.org/D20307

llvm-svn: 269995
2016-05-18 22:41:03 +00:00
Dehao Chen f6c0083b55 clang-format SimplifyCFG.cpp.
llvm-svn: 269974
2016-05-18 19:44:21 +00:00
Davide Italiano bfe3801d16 [LCSSA] Use llvm::any_of instead of std::size_of.
The API is simpler. Suggested by David Blaikie!

llvm-svn: 269800
2016-05-17 19:01:02 +00:00
Davide Italiano a0e0feea1d [PM/LCSSA] Fix dependency list. Some passes are preserved, not required.
llvm-svn: 269768
2016-05-17 14:32:12 +00:00
Davide Italiano b75b16e2ff [LCSSA] Use any_of() to simplify the code. NFCI.
llvm-svn: 269767
2016-05-17 14:24:41 +00:00
Sanjay Patel 5d5134f676 use range-loops; NFCI
llvm-svn: 269471
2016-05-13 20:24:53 +00:00
Chandler Carruth 49c22190d0 [PM] Port of the DepndenceAnalysis to the new PM.
Ported DA to the new PM by splitting the former DependenceAnalysis Pass
into a DependenceInfo result type and DependenceAnalysisWrapperPass type
and adding a new PM-style DependenceAnalysis analysis pass returning the
DependenceInfo.

Patch by Philip Pfaffe, most of the review by Justin.

Differential Revision: http://reviews.llvm.org/D18834

llvm-svn: 269370
2016-05-12 22:19:39 +00:00
Sanjoy Das e0aa414acf All llvm.deoptimize declarations must use the same calling convention
This new verifier rule lets us unambigously pick a calling convention
when creating a new declaration for
`@llvm.experimental.deoptimize.<ty>`.  It is also congruent with our
lowering strategy -- since all calls to `@llvm.experimental.deoptimize`
are lowered to calls to `__llvm_deoptimize`, it is reasonable to enforce
a unique calling convention.

Some of the tests that were breaking this verifier rule have had to be
split up into different .ll files.

The inliner was violating this rule as well, and has been fixed to avoid
producing invalid IR.

llvm-svn: 269261
2016-05-12 01:17:38 +00:00
Dehao Chen b76e5d948a Propagate branch metadata when some branch probability is missing.
Summary: In sample profile, some branches may have profile missing due to profile inaccuracy. We want existing branch probability still valid after propagation.

Reviewers: hfinkel, davidxl, spatel

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D19948

llvm-svn: 269137
2016-05-10 23:07:19 +00:00
Peter Collingbourne dba995601b Cloning: Clean up the interface to the CloneFunction function.
Remove the ModuleLevelChanges argument, and the ability to create new
subprograms for cloned functions. The latter was added without review in
r203662, but it has no in-tree clients (all non-test callers pass false
for ModuleLevelChanges [1], so it isn't reachable outside of tests). It
also isn't clear that adding a duplicate subprogram to the compile unit is
always the right thing to do when cloning a function within a module. If
this functionality comes back it should be accompanied with a more concrete
use case.

Furthermore, all in-tree clients add the returned function to the module.
Since that's pretty much the only sensible thing you can do with the function,
just do that in CloneFunction.

[1] http://llvm-cs.pcc.me.uk/lib/Transforms/Utils/CloneFunction.cpp/rCloneFunction

Differential Revision: http://reviews.llvm.org/D18628

llvm-svn: 269110
2016-05-10 20:23:24 +00:00
Elena Demikhovsky c434d091c5 [LoopVectorize] Handling induction variable with non-constant step.
Allow vectorization when the step is a loop-invariant variable.
This is the loop example that is getting vectorized after the patch:

 int int_inc;
 int bar(int init, int *restrict A, int N) {

  int x = init;
  for (int i=0;i<N;i++){
    A[i] = x;
    x += int_inc;
  }
  return x;
 }

"x" is an induction variable with *loop-invariant* step.
But it is not a primary induction. Primary induction variable with non-constant step is not handled yet.

Differential Revision: http://reviews.llvm.org/D19258

llvm-svn: 269023
2016-05-10 07:33:35 +00:00
Justin Lebar 50deb6d028 Minor formatting fixes in LoopUnroll.cpp.
llvm-svn: 268995
2016-05-10 00:31:23 +00:00
Joerg Sonnenberger 8ffe7ab7c2 Optimize a printf with a double procent to putchar.
llvm-svn: 268922
2016-05-09 14:36:16 +00:00
Junmo Park 955298746d Minor code cleanups. NFC.
llvm-svn: 268888
2016-05-08 23:22:58 +00:00
Sanjay Patel 1cb6241a89 [SimplifyCFG] propagate branch metadata when creating select (retry r268550 / r268751 with possible fix)
Retrying r268550/r268751 which were reverted at r268577/r268765 due a memory sanitizer failure.
I have not been able to reproduce that failure, but I've taken another guess at fixing
the problem in this version of the patch and will watch for another failure.

Original commit message:
Unlike earlier similar fixes, we need to recalculate the branch weights
in this case.

Differential Revision: http://reviews.llvm.org/D19674

llvm-svn: 268767
2016-05-06 18:07:46 +00:00
Sanjay Patel 84a0bf64a8 revert r268751 - caused same failures on msan bot
llvm-svn: 268765
2016-05-06 17:51:37 +00:00
Sanjay Patel 6609510c32 [SimplifyCFG] propagate branch metadata when creating select (retry r268550 with possible fix)
Retrying r268550 which was reverted at r268577 due a memory sanitizer failure.
I have not been able to reproduce that failure, but I've taken a guess at fixing
the problem in this version of the patch and will watch for another failure.

Original commit message:
Unlike earlier similar fixes, we need to recalculate the branch weights
in this case.

Differential Revision: http://reviews.llvm.org/D19674

llvm-svn: 268751
2016-05-06 17:07:47 +00:00
Chad Rosier 4ab37c0037 [SimplifyCFG] Prefer a simplification based on a dominating condition.
Rather than merge two branches with a common destination.
Differential Revision: http://reviews.llvm.org/D19743

llvm-svn: 268735
2016-05-06 14:25:14 +00:00
Mehdi Amini 3b132e34b0 ThinLTO: fix assertion and refactor check for hidden use from inline ASM in a helper function
This test was crashing, and currently it breaks bootstrapping clang with debuginfo

Differential Revision: http://reviews.llvm.org/D20008

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 268715
2016-05-06 08:25:33 +00:00
Dehao Chen f50c67ce7c Revert http://reviews.llvm.org/D19926 as it breaks tests.
llvm-svn: 268681
2016-05-05 20:47:53 +00:00
Dehao Chen e48b4ee98c Simplify CFG before assigning discriminator.
Summary: We need to clean up CFG before assigning discriminator to minimize the impact of optimization on debug info.

Reviewers: davidxl, dblaikie, dnovillo

Subscribers: dnovillo, danielcdh, llvm-commits

Differential Revision: http://reviews.llvm.org/D19926

llvm-svn: 268675
2016-05-05 20:18:49 +00:00
Silviu Baranga c05bab8a9c [LV] Identify more induction PHIs by coercing expressions to AddRecExprs
Summary:
Some PHIs can have expressions that are not AddRecExprs due to the presence
of sext/zext instructions. In order to prevent the Loop Vectorizer from
bailing out when encountering these PHIs, we now coerce the SCEV
expressions to AddRecExprs using SCEV predicates (when possible).

We only do this when the alternative would be to not vectorize.

Reviewers: mzolotukhin, anemet

Subscribers: mssimpso, sanjoy, mzolotukhin, llvm-commits

Differential Revision: http://reviews.llvm.org/D17153

llvm-svn: 268633
2016-05-05 15:20:39 +00:00
Vitaly Buka fdcea9d78a Revert "[SimplifyCFG] propagate branch metadata when creating select"
MemorySanitizer: use-of-uninitialized-value
0x4910e47 in count /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/include/llvm/Support/MathExtras.h:159:12
0x4910e47 in countLeadingZeros<unsigned long> /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/include/llvm/Support/MathExtras.h:183
0x4910e47 in FitWeights /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/Transforms/Utils/SimplifyCFG.cpp:855
0x4910e47 in SimplifyCondBranchToCondBranch /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/Transforms/Utils/SimplifyCFG.cpp:2895

This reverts commit 609f4dd4bf3bc735c8c047a4d4b0a8e9e4d202e2.

llvm-svn: 268577
2016-05-04 23:59:33 +00:00
Sanjay Patel 7e8c285814 [SimplifyCFG] propagate branch metadata when creating select
Unlike earlier similar fixes, we need to recalculate the branch weights
in this case.

Differential Revision: http://reviews.llvm.org/D19674

llvm-svn: 268550
2016-05-04 20:48:24 +00:00
Hans Wennborg 0c3518e84b [SimplifyCFG] isSafeToSpeculateStore now ignores debug info
This patch fixes PR27615.

@llvm.dbg.value instructions no longer count towards the maximum number of
instructions to look back at in the instruction list when searching for a
store instruction. This should make the output consistent between debug and
non-debug build.

Patch by Henric Karlsson <henric.karlsson@ericsson.com>!

Differential Revision: http://reviews.llvm.org/D19912

llvm-svn: 268512
2016-05-04 15:40:57 +00:00
David Majnemer 95549497ec [GlobalDCE, Misc] Don't remove functions referenced by ifuncs
We forgot to consider the target of ifuncs when considering if a
function was alive or dead.

N.B. Also update a few auxiliary tools like bugpoint and
verify-uselistorder.

This fixes PR27593.

llvm-svn: 268468
2016-05-04 00:20:48 +00:00
Andrew Kaylor 50271f787e Add opt-bisect support to additional passes that can be skipped
Differential Revision: http://reviews.llvm.org/D19882

llvm-svn: 268457
2016-05-03 22:32:30 +00:00
Reid Kleckner bca59d2a43 Revert "[SimplifyCFG] Extend TryToSimplifyUncondBranchFromEmptyBlock for empty block including lifetime intrinsics"
This reverts commit r268254.

This change causes assertion failures while building Chromium. Reduced
test case coming soon.

llvm-svn: 268288
2016-05-02 19:43:22 +00:00
Hans Wennborg b7599329fc [SimplifyCFG] Extend TryToSimplifyUncondBranchFromEmptyBlock for empty block including lifetime intrinsics
Make it possible that TryToSimplifyUncondBranchFromEmptyBlock merges empty
basic block including lifetime intrinsics as well as phi nodes and
unconditional branch into its successor or predecessor(s).

If successor of empty block has single predecessor, all contents including
lifetime intrinsics are sinked into the successor. Otherwise, they are
hoisted into its predecessor(s) and then merged into the predecessor(s).

Patch by Josh Yoon <josh.yoon@samsung.com>!

Differential Revision: http://reviews.llvm.org/D19257

llvm-svn: 268254
2016-05-02 17:22:54 +00:00
Sanjoy Das 107aefc2fc Mark guards on true as "trivially dead"
This moves some logic added to EarlyCSE in rL268120 into
`llvm::isInstructionTriviallyDead`.  Adds a test case for DCE to
demonstrate that passes other than EarlyCSE can now pick up on the new
information.

llvm-svn: 268126
2016-04-29 22:23:16 +00:00
George Burgess IV 1b1fef30d0 [MemorySSA] Fix bugs in walker; refactor unittests a bit.
This patch fixes two somewhat related bugs in MemorySSA's caching
walker. These bugs were found because D19695 brought up the problem
that we'd have defs cached to themselves, which is incorrect.

The bugs this fixes are:

- We would sometimes skip the nearest clobber of a MemoryAccess, because
  we would query our cache for a given potential clobber before
  checking if the potential clobber is the clobber we're looking for.
  The cache entry for the potential clobber would point to the nearest
  clobber *of the potential clobber*, so if that was a cache hit, we'd
  ignore the potential clobber entirely.

- There are times (sometimes in DFS, sometimes in the getClobbering...
  functions) where we would insert cache entries that say a def
  clobbers itself.

There's a bit of common code between the fixes for the bugs, so they
aren't split out into multiple commits.

This patch also adds a few unit tests, and refactors existing tests a
bit to reduce the duplication of setup code.

llvm-svn: 268087
2016-04-29 18:42:55 +00:00
Filipe Cabecinhas 0da9937517 Unify XDEBUG and EXPENSIVE_CHECKS (into the latter), and add an option to the cmake build to enable them.
Summary:
Historically, we had a switch in the Makefiles for turning on "expensive
checks". This has never been ported to the cmake build, but the
(dead-ish) code is still around.

This will also make it easier to turn it on in buildbots.

Reviewers: chandlerc

Subscribers: jyknight, mzolotukhin, RKSimon, gberry, llvm-commits

Differential Revision: http://reviews.llvm.org/D19723

llvm-svn: 268050
2016-04-29 15:22:48 +00:00
Hal Finkel 50316d95a9 [Inliner] Preserve llvm.mem.parallel_loop_access metadata
When inlining a call site with llvm.mem.parallel_loop_access metadata, this
metadata needs to be propagated to all cloned memory-accessing instructions.
Otherwise, inlining parts of the loop body will invalidate the annotation.

With this functionality, we now vectorize the following as expected:

  void Body(int *res, int *c, int *d, int *p, int i) {
    res[i] = (p[i] == 0) ? res[i] : res[i] + d[i];
  }

  void Test(int *res, int *c, int *d, int *p, int n) {
    int i;

  #pragma clang loop vectorize(assume_safety)
    for (i = 0; i < 1600; i++) {
      Body(res, c, d, p, i);
    }
  }

llvm-svn: 267949
2016-04-28 23:00:04 +00:00
Sanjay Patel facf45a82f [SimplifyCFG] propagate branch metadata when creating select
There's no existing test for this path, and I don't know how to expose
it in a regression test, but I'm assuming there's some reason this
path exists. 

llvm-svn: 267813
2016-04-27 23:14:12 +00:00
Ahmed Bougacha 44c19876c7 [InferAttrs] Mark memset_pattern16 params nocapture.
Differential Revision: http://reviews.llvm.org/D19471

llvm-svn: 267760
2016-04-27 19:04:43 +00:00
Ahmed Bougacha b0624a2cb4 [TLI] Unify LibFunc attribute inference. NFCI.
Now the pass is just a tiny wrapper around the util. This lets us reuse
the logic elsewhere (done here for BuildLibCalls) instead of duplicating
it.

The next step is to have something like getOrInsertLibFunc that also
sets the attributes.

Differential Revision: http://reviews.llvm.org/D19470

llvm-svn: 267759
2016-04-27 19:04:40 +00:00
Ahmed Bougacha d765a82b54 [TLI] Unify LibFunc signature checking. NFCI.
I tried to be as close as possible to the strongest check that
existed before; cleaning these up properly is left for future work.

Differential Revision: http://reviews.llvm.org/D19469

llvm-svn: 267758
2016-04-27 19:04:35 +00:00
Teresa Johnson df5ef8711f [ThinLTO] Refine fix to avoid renaming of uses in inline assembly.
Summary:
Refine the workaround from r266877 that attempts to prevent
renaming of locals in inline assembly, so that in addition to looking
for a llvm.used local value, that there is at least one inline assembly
call in the module. Otherwise, debug functions added to the llvm.used
can block importing/exporting unnecessarily.

Reviewers: joker.eph

Subscribers: llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D19573

llvm-svn: 267717
2016-04-27 14:19:38 +00:00
Vaivaswatha Nagaraj 08efb0efcd [Cloning] cloneLoopWithPreheader(): add assert to ensure no sub-loops
Summary:
cloneLoopWithPreheader() does not update LoopInfo for sub-loop of
the original loop being cloned. Add assert to ensure no sub-loops for loop being cloned.

Reviewers: anemet, ashutosh.nema, hfinkel

Subscribers: mzolotukhin, llvm-commits

Differential Revision: http://reviews.llvm.org/D15922

llvm-svn: 267671
2016-04-27 05:25:09 +00:00
Evgeny Stupachenko 23ce61b663 The patch fixes PR27392.
Summary:
 It is incorrect to compare TripCount (which is BECount + 1)
  with extraiters (or Count) to check if we should enter unrolled
  loop or not, because TripCount can potentially overflow
  (when BECount is max unsigned integer).
 While comparing BECount with (Count - 1) is overflow safe and
  therefore correct.

Reviewer: hfinkel

Differential Revision: http://reviews.llvm.org/D19256

From: Evgeny Stupachenko <evstupac@gmail.com>
llvm-svn: 267662
2016-04-27 03:04:54 +00:00
Mehdi Amini b4e1e8297b ThinLTO: do not promote GlobalVariable that have a specific section.
Differential Revision: http://reviews.llvm.org/D18298

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267646
2016-04-27 00:32:13 +00:00
Sanjay Patel 29dea0d230 [SimplifyCFG] propagate branch metadata when creating select
llvm-svn: 267624
2016-04-26 23:15:48 +00:00
David Majnemer abb9f55c80 Revert "[SimplifyLibCalls] sprintf doesn't copy null bytes"
The destination buffer that sprintf uses is restrict qualified, we do
not need to worry about derived pointers referenced via format
specifiers.

This reverts commit r267580.

llvm-svn: 267605
2016-04-26 21:04:47 +00:00
David Majnemer 8cd77baebc [SimplifyLibCalls] sprintf doesn't copy null bytes
sprintf doesn't read or copy the terminating null byte from it's string
operands.  sprintf will append it's own after processing all of the
format specifiers.

This fixes PR27526.

llvm-svn: 267580
2016-04-26 18:16:49 +00:00
Hal Finkel e4c0c1679b [SimplifyCFG] Preserve !llvm.mem.parallel_loop_access when merging
When SimplifyCFG merges identical instructions from both sides of a diamond, it
can preserve !llvm.mem.parallel_loop_access (as it does with most of the other
metadata). There's no real data or control dependency change in this case.

llvm-svn: 267515
2016-04-26 02:06:06 +00:00
Chad Rosier e2cbd13e56 [ValueTracking] Improve isImpliedCondition when the dominating cond is false.
llvm-svn: 267430
2016-04-25 17:23:36 +00:00
Sanjay Patel dc88bd6e1f replace duplicated static functions for profile metadata access with BranchInst member function; NFCI
llvm-svn: 267295
2016-04-23 20:01:22 +00:00
Sanjay Patel 85ce0f1f1f improve documentation comments; NFC
llvm-svn: 267292
2016-04-23 16:31:48 +00:00
Andrew Kaylor aa641a5171 Re-commit optimization bisect support (r267022) without new pass manager support.
The original commit was reverted because of a buildbot problem with LazyCallGraph::SCC handling (not related to the OptBisect handling).

Differential Revision: http://reviews.llvm.org/D19172

llvm-svn: 267231
2016-04-22 22:06:11 +00:00
Adam Nemet fe3def7c2a [LoopUtils] Extend findStringMetadataForLoop to return the value for metadata
E.g. for:

  !1 = {"llvm.distribute", i32 1}

it now returns the MDOperand for 1.

I will use this in LoopDistribution to check the value of the metadata.

Note that the change is backward-compatible with its current use in
LoopVersioningLICM.  An Optional implicitly converts to a bool depending
whether it contains a value or not.

llvm-svn: 267190
2016-04-22 19:10:05 +00:00
Geoff Berry 9fe26e6dc9 [MemorySSA] Fix bug in CachingMemorySSAWalker::invalidateInfo
Summary:
CachingMemorySSAWalker::invalidateInfo was using IsCall to determine
which cache map needed to be cleared of entries referring to the invalidated
MemoryAccess, but there could also be entries referring to it in the
other cache map (value entries, not key entries).  This change just
clears both tables to be conservatively correct.

Also add a verifyRemoved() function, called when expensive
checks (i.e. XDEBUG) are enabled to verify that the invalidated
MemoryAccess object is not referenced in any of the caches.

Reviewers: dberlin, george.burgess.iv

Subscribers: mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D19388

llvm-svn: 267157
2016-04-22 14:44:10 +00:00