Commit Graph

3566 Commits

Author SHA1 Message Date
Anna Thomas b555cc8cb6 NFC: [LoopUnroll] More meaningful message in tracing
llvm-svn: 294017
2017-02-03 17:12:43 +00:00
Peter Collingbourne 6d8f817f8b FunctionImport: Use IRMover directly.
The importer was previously using ModuleLinker in a sort of "IRMover mode". Use
IRMover directly instead in order to remove a level of indirection.

I will remove all importing support from ModuleLinker in a separate
change.

Differential Revision: https://reviews.llvm.org/D29468

llvm-svn: 294014
2017-02-03 16:56:27 +00:00
Michael Kuperstein 3c6b3ba258 Shut up another GCC warning about operator precedence. NFC.
llvm-svn: 293812
2017-02-01 21:06:33 +00:00
Florian Hahn a35b8a4852 [LoopUnroll] Use addClonedBlockToLoopInfo to add loop header to LI (NFC).
Summary:
I have a similar patch up for review already (D29173). If you prefer I
can squash them both together.

Also I think there more potential for code sharing between
LoopUnroll.cpp and LoopUnrollRuntime.cpp. Do you think patches for
that would be worthwhile? 

Reviewers: mkuper, mzolotukhin

Reviewed By: mkuper, mzolotukhin

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29311

llvm-svn: 293758
2017-02-01 10:39:35 +00:00
Florian Hahn 5364cf3b56 [LoopUnroll] Use addClonedBlockToLoopInfo to clone the top level loop (NFC)
Summary:
rL293124 added the necessary infrastructure to properly add the cloned
top level loop to LoopInfo, which means we do not have to do it manually
in CloneLoopBlocks.

@mkuper sorry for not pointing this out during my review of D29156, I just
realized that today.


Reviewers: mzolotukhin, chandlerc, mkuper

Reviewed By: mkuper

Subscribers: llvm-commits, mkuper

Differential Revision: https://reviews.llvm.org/D29173

llvm-svn: 293615
2017-01-31 11:13:44 +00:00
Daniel Berlin 9d8a335ce0 Revert "[MemorySSA] Revert r293361 and r293363, as the tests fail under asan."
This reverts commit r293471, reapplying r293361 and r293363 with a fix
for an out-of-bounds read.

llvm-svn: 293474
2017-01-30 11:35:39 +00:00
Sam McCall b9d6c10c2d [MemorySSA] Revert r293361 and r293363, as the tests fail under asan.
llvm-svn: 293471
2017-01-30 09:19:50 +00:00
Davide Italiano 6c77de0367 [MemorySSA] Correct an assertion surrounding with parentheses.
llvm-svn: 293453
2017-01-30 03:16:43 +00:00
Taewook Oh 505a25aec5 [InstCombine] Merge DebugLoc when speculatively hoisting store instruction
Summary: Along with https://reviews.llvm.org/D27804, debug locations need to be merged when hoisting store instructions as well. Not sure if just dropping debug locations would make more sense for this case, but as the branch instruction will have at least different discriminator with the hoisted store instruction, I think there will be no difference in practice.

Reviewers: aprantl, andreadb, danielcdh

Reviewed By: aprantl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29062

llvm-svn: 293372
2017-01-28 07:05:43 +00:00
Daniel Berlin ee6e3a598a MemorySSA: Allow movement to arbitrary places
Summary: Extend the MemorySSAUpdater API to allow movement to arbitrary places

Reviewers: davide, george.burgess.iv

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29239

llvm-svn: 293363
2017-01-28 02:26:39 +00:00
Daniel Berlin 2f1ab4ba79 MemorySSA: Fix block numbering invalidation and replacement bugs discovered by updater
llvm-svn: 293361
2017-01-28 02:22:52 +00:00
Matthias Braun 8c209aa877 Cleanup dump() functions.
We had various variants of defining dump() functions in LLVM. Normalize
them (this should just consistently implement the things discussed in
http://lists.llvm.org/pipermail/cfe-dev/2014-January/034323.html

For reference:
- Public headers should just declare the dump() method but not use
  LLVM_DUMP_METHOD or #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
- The definition of a dump method should look like this:
  #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
  LLVM_DUMP_METHOD void MyClass::dump() {
    // print stuff to dbgs()...
  }
  #endif

llvm-svn: 293359
2017-01-28 02:02:38 +00:00
Daniel Berlin ae6b8b6933 MemorySSA: Move updater to its own file
llvm-svn: 293357
2017-01-28 01:35:02 +00:00
Daniel Berlin 60ead05f80 Introduce a basic MemorySSA updater, that supports insertDef,
insertUse, moveBefore and moveAfter operations.

Summary:
This creates a basic MemorySSA updater that handles arbitrary
insertion of uses and defs into MemorySSA, as well as arbitrary
movement around the CFG. It replaces the current splice API.

It can be made to handle arbitrary control flow changes.
Currently, it uses the same updater algorithm from D28934.

The main difference is because MemorySSA is single variable, we have
the complete def and use list, and don't need anyone to give it to us
as part of the API.  We also have to rename stores below us in some
cases.

If we go that direction in that patch, i will merge all the updater
implementations (using an updater_traits or something to provide the
get* functions we use, called read*/write* in that patch).

Sadly, the current SSAUpdater algorithm is way too slow to use for
what we are doing here.

I have updated the tests we have to basically build memoryssa
incrementally using the updater api, and make sure it still comes out
the same.

Reviewers: george.burgess.iv

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29047

llvm-svn: 293356
2017-01-28 01:23:13 +00:00
Anna Thomas e7d865e34e NFC: Add debug tracing for more cases where loop unrolling fails.
llvm-svn: 293313
2017-01-27 17:57:05 +00:00
Justin Lebar cb9b41dd76 [LangRef] Make @llvm.sqrt(x) return undef, rather than have UB, for negative x.
Summary:
Some frontends emit a speculate-and-select idiom for sqrt, wherein they compute
sqrt(x), check if x is negative, and select NaN if it is:

  %cmp = fcmp olt double %a, -0.000000e+00
  %sqrt = call double @llvm.sqrt.f64(double %a)
  %ret = select i1 %cmp, double 0x7FF8000000000000, double %sqrt

This is technically UB as the LangRef is written today if %a is ever less than
-0.  But emitting code that's compliant with the current definition of sqrt
would require a branch, which would then prevent us from matching this idiom in
SelectionDAG (which we do today -- ISD::FSQRT has defined behavior on negative
inputs), because SelectionDAG looks at one BB at a time.

Nothing in LLVM takes advantage of this undefined behavior, as far as we can
tell, and the fact that llvm.sqrt has UB dates from its initial addition to the
LangRef.

Reviewers: arsenm, mehdi_amini, hfinkel

Subscribers: wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D28797

llvm-svn: 293242
2017-01-27 00:58:03 +00:00
Michael Kuperstein 5dd55e8405 [LoopUnroll] Properly update loopinfo for runtime unrolling by 2
Even when we don't create a remainder loop (that is, when we unroll by 2), we
may duplicate nested loops into the remainder. This is complicated by the fact
the remainder may itself be either inserted into an outer loop, or at the top
level. In the latter case, we may need to create new top-level loops.

Differential Revision: https://reviews.llvm.org/D29156

llvm-svn: 293124
2017-01-26 01:04:11 +00:00
Daniel Berlin d602e04c9e MemorySSA: Link all defs together into an intrusive defslist, to make updater easier
Summary:
This is the first in a series of patches to add a simple, generalized updater to MemorySSA.

For MemorySSA, every def is may-def, instead of the normal must-def.
(the best way to think of memoryssa is "everything is really one variable, with different versions of that variable at different points in the program).
This means when updating, we end up having to do a bunch of work to touch defs below and above us.

In order to support this quickly, i have ilist'd all the defs for each block.  ilist supports tags, so this is quite easy. the only slightly messy part is that you can't have two iplists for the same type that differ only whether they have the ownership part enabled or not, because the traits are for the value type.

The verifiers have been updated to test that the def order is correct.

Reviewers: george.burgess.iv

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29046

llvm-svn: 293085
2017-01-25 20:56:19 +00:00
Akira Hatanaka 4ec7b20ef6 [SimplifyCFG] Do not sink and merge inline-asm instructions.
Conservatively disable sinking and merging inline-asm instructions as doing so
can potentially create arguments that cannot satisfy the inline-asm constraints.

For example, SimplifyCFG used to do the following transformation:

(before)
if.then:
  %0 = call i32 asm "rorl $2, $0", "=&r,0,n"(i32 %r6, i32 8)
  br label %if.end
if.else:
  %1 = call i32 asm "rorl $2, $0", "=&r,0,n"(i32 %r6, i32 6)
  br label %if.end

(after)
  %.sink = select i1 %tobool, i32 6, i32 8
  %0 = call i32 asm "rorl $2, $0", "=&r,0,n"(i32 %r6, i32 %.sink)

This would result in a crash in the backend since only immediate integer operands
are permitted for constraint "n".

rdar://problem/30110806

Differential Revision: https://reviews.llvm.org/D29111

llvm-svn: 293025
2017-01-25 06:21:51 +00:00
Chandler Carruth 6acdca78a0 [PH] Replace uses of AssertingVH from members of analysis results with
a lazy-asserting PoisoningVH.

AssertVH is fundamentally incompatible with cache-invalidation of
analysis results. The invaliadtion happens after the AssertingVH has
already fired. Instead, use a PoisoningVH that will assert if the
dangling handle is ever used rather than merely be assigned or
destroyed.

This patch also removes all of the (numerous) doomed attempts to work
around this fundamental incompatibility. It is a pretty significant
simplification IMO.

The most interesting change is in the Inliner where we still do some
clearing because we don't want to rely on the coarse grained
invalidation strategy of the containing pass manager. However, I prefer
the approach that contains this logic to the cleanup phase of the
Inliner, and I think we could enhance the CGSCC analysis management
layer to make this even better in the future if desired.

The rest is straight cleanup.

I've also added a test for one of the harder cases to work around: when
a *module analysis* contains many AssertingVHes pointing at functions.

Differential Revision: https://reviews.llvm.org/D29006

llvm-svn: 292928
2017-01-24 12:55:57 +00:00
Serge Pavlov 098ee2fe02 Update domtree incrementally in loop peeling.
With this change dominator tree remains in sync after each step of loop
peeling.

Differential Revision: https://reviews.llvm.org/D29029

llvm-svn: 292895
2017-01-24 06:58:39 +00:00
Matt Arsenault 954a624fb9 SimplifyLibCalls: Replace more unary libcalls with intrinsics
llvm-svn: 292855
2017-01-23 23:55:08 +00:00
Michael Kuperstein 461aa57ad3 [LoopUnroll] First form LCSSA, then loop-simplify
Running non-LCSSA-preserving LoopSimplify followed by LCSSA on (roughly) the
same loop is incorrect, since LoopSimplify may break LCSSA arbitrarily higher
in the loop nest. Instead, run LCSSA first, and then run LCSSA-preserving
LoopSimplify on the result.

This fixes PR31718.

Differential Revision: https://reviews.llvm.org/D29055

llvm-svn: 292854
2017-01-23 23:45:42 +00:00
David L. Jones d21529fa0d [Analysis] Add LibFunc_ prefix to enums in TargetLibraryInfo. (NFC)
Summary:
The LibFunc::Func enum holds enumerators named for libc functions.
Unfortunately, there are real situations, including libc implementations, where
function names are actually macros (musl uses "#define fopen64 fopen", for
example; any other transitively visible macro would have similar effects).

Strictly speaking, a conforming C++ Standard Library should provide any such
macros as functions instead (via <cstdio>). However, there are some "library"
functions which are not part of the standard, and thus not subject to this
rule (fopen64, for example). So, in order to be both portable and consistent,
the enum should not use the bare function names.

The old enum naming used a namespace LibFunc and an enum Func, with bare
enumerators. This patch changes LibFunc to be an enum with enumerators prefixed
with "LibFFunc_". (Unfortunately, a scoped enum is not sufficient to override
macros.)

There are additional changes required in clang.

Reviewers: rsmith

Subscribers: mehdi_amini, mzolotukhin, nemanjai, llvm-commits

Differential Revision: https://reviews.llvm.org/D28476

llvm-svn: 292848
2017-01-23 23:16:46 +00:00
Amaury Sechet 2fec7e4f44 Tweak ASCII art in Simplify CFG. NFC
llvm-svn: 292792
2017-01-23 15:13:01 +00:00
Chandler Carruth 7fd29cef42 [PM] Sink an LCSSA preservation assert from the LoopSimplify pass into
the library routine shared with the new PM and other code.

This assert checks that when LCSSA preservation is requested we start in
LCSSA form. Without this early assert, given *very* complex test cases
we can hit an assert or crash much later on when trying to preserve
LCSSA.

The new PM's loop simplify doesn't need to (and indeed can't) preserve
LCSSA as the new PM doesn't deal in transforms in the dependency graph.
But we asked the library to and shockingly, this didn't work very well!
Stop doing that. Now the assert will tell us immediately with existing
test cases. Before this, it took a pretty convoluted input to trigger
this.

However, sinking the assert also found a bug in LoopUnroll where we
asked simplifyLoop to preserve LCSSA *right before we reform it*. That's
kinda silly and unsurprising that it wasn't available. =D Stop doing
that too.

We also would assert that the unrolled loop was in LCSSA even if
preserving LCSSA was never requested! I don't have a test case or
anything here. I spotted it by inspection and it seems quite obvious. No
logic change anyways, that's just avoiding a spurrious assert.

llvm-svn: 292710
2017-01-21 04:16:53 +00:00
Easwaran Raman 12585b0148 Improve PGO support for the new inliner
This adds the following to the new PM based inliner in PGO mode:

* Use block frequency analysis to derive callsite's profile count and use
that to adjust thresholds of hot and cold callsites.

* Incrementally update the BFI of the caller after a callee gets inlined
into it. This incremental update is only within an invocation of the run
method - BFI is not preserved across calls to run.
Update the function entry count of the callee after inlining it into a
caller.

* I've tuned the thresholds for the hot and cold callsites using a hacked
up version of the old inliner that explicitly computes BFI on a set of
internal benchmarks and spec. Once the new PM based pipeline stabilizes
(IIRC Chandler mentioned there are known issues) I'll benchmark this
again and adjust the thresholds if required.
Inliner PGO support.

Differential revision: https://reviews.llvm.org/D28331

llvm-svn: 292666
2017-01-20 22:44:04 +00:00
Eli Friedman 0a2174533e Preserve domtree and loop-simplify for runtime unrolling.
Mostly straightforward changes; we just didn't do the computation before.
One sort of interesting change in LoopUnroll.cpp: we weren't handling
dominance for children of the loop latch correctly, but
foldBlockIntoPredecessor hid the problem for complete unrolling.

Currently punting on loop peeling; made some minor changes to isolate
that problem to LoopUnrollPeel.cpp.

Adds a flag -unroll-verify-domtree; it verifies the domtree immediately
after we finish updating it. This is on by default for +Asserts builds.

Differential Revision: https://reviews.llvm.org/D28073

llvm-svn: 292447
2017-01-18 23:26:37 +00:00
Peter Collingbourne 10e3b12c7a Cloning: Copy comdats when cloning globals.
Differential Revision: https://reviews.llvm.org/D28838

llvm-svn: 292430
2017-01-18 20:02:31 +00:00
Michael Kuperstein 0de990da16 Fix up a comment. NFC.
llvm-svn: 292425
2017-01-18 19:05:48 +00:00
Michael Kuperstein 7cefb409b0 [LV] Allow reductions that have several uses outside the loop
We currently check whether a reduction has a single outside user. We don't
really need to require that - we just need to make sure a single value is
used externally. The number of external users of that value shouldn't actually
matter.

Differential Revision: https://reviews.llvm.org/D28830

llvm-svn: 292424
2017-01-18 19:02:52 +00:00
Eugene Zelenko 34c23279c2 [Target, Transforms] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).
llvm-svn: 292320
2017-01-18 00:57:48 +00:00
Matt Arsenault b948b4d8df SimplifyLibCalls: Remove checks for fabs
Use the intrinsic instead of emitting the libcall which
will be replaced by the intrinsic.

llvm-svn: 292176
2017-01-17 00:30:31 +00:00
Matt Arsenault 7233344c28 SimplifyLibCalls: Replace fabs libcalls with intrinsics
Add missing fabs(fpext) optimzation that worked with the call,
and also fixes it creating a second fpext when there were multiple
uses.

llvm-svn: 292172
2017-01-17 00:10:40 +00:00
Chandler Carruth ca68a3ec47 [PM] Introduce an analysis set used to preserve all analyses over
a function's CFG when that CFG is unchanged.

This allows transformation passes to simply claim they preserve the CFG
and analysis passes to check for the CFG being preserved to remove the
fanout of all analyses being listed in all passes.

I've gone through and removed or cleaned up as many of the comments
reminding us to do this as I could.

Differential Revision: https://reviews.llvm.org/D28627

llvm-svn: 292054
2017-01-15 06:32:49 +00:00
Eugene Zelenko 5fa43960f3 [Transforms/Utils] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).
llvm-svn: 291983
2017-01-14 00:32:38 +00:00
David L. Jones 41cecba8e9 "Use" lambda captures which are otherwise only used in asserts. NFC
Summary:
The LLVM coding standards recommend "using" values that are only
needed by asserts:
http://llvm.org/docs/CodingStandards.html#assert-liberally

Without this change, LLVM cannot bootstrap with -Werror as the second
stage fails with this new warning:
https://reviews.llvm.org/rL291905

See also the previous fixes:
https://reviews.llvm.org/rL291916
https://reviews.llvm.org/rL291939
https://reviews.llvm.org/rL291940
https://reviews.llvm.org/rL291941

Reviewers: rsmith

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D28695

llvm-svn: 291957
2017-01-13 21:02:41 +00:00
Robert Lougher b0124c1eb8 [DebugInfo] Remove redundant check in SimplifyCFG; NFC.
llvm-svn: 291813
2017-01-12 21:11:09 +00:00
Robert Lougher 6717a6fe54 [DebugInfo] DILocation variable declaration should be const; NFC.
llvm-svn: 291787
2017-01-12 18:33:49 +00:00
Florian Hahn 4f9d6d56c0 [loop-unroll] Properly populate LoopInfo for loops cloned in LoopUnrollRuntime.
Summary:
This fixes Transforms/LoopUnroll/runtime-loop3.ll which failed with
EXTENSIVE_DEBUG, because the cloned basic blocks were not added to the
correct sub-loops in LoopUnrollRuntime.cpp.


Reviewers: dexonsmith, mzolotukhin

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D28482

llvm-svn: 291619
2017-01-10 23:43:35 +00:00
Florian Hahn fdea2e420c [loop-unroll] Factor out code to update LoopInfo (NFC).
Move the code to update LoopInfo for cloned basic blocks to
addClonedBlockToLoopInfo, as suggested in 
https://reviews.llvm.org/D28482.

llvm-svn: 291614
2017-01-10 23:24:54 +00:00
Michael Kuperstein ee31cbe35f [LV] Don't panic when encountering the IV of an outer loop.
Bail out instead of asserting when we encounter this situation,
which can actually happen.

The reason the test uses the new PM is that the "bad" phi, incidentally, gets
cleaned up by LoopSimplify. But LICM can create this kind of phi and preserve
loop simplify form, so the cleanup has no chance to run.

This fixes PR31190.
We may want to solve this in a less conservative manner, since this phi is
actually uniform within the inner loop (or we may want LICM to output a cleaner
promotion to begin with).

Differential Revision: https://reviews.llvm.org/D28490

llvm-svn: 291589
2017-01-10 19:32:30 +00:00
Davide Italiano f8711f093e [SimplifyLibCalls] Propagate fast math flags while optimizing pow().
llvm-svn: 291577
2017-01-10 18:02:05 +00:00
Davide Italiano 472684eaf5 [SimplifyLibCalls] pow(x, -0.5) -> 1.0 / sqrt(x).
Differential Revision:  https://reviews.llvm.org/D28479

llvm-svn: 291486
2017-01-09 21:55:23 +00:00
Matt Arsenault a7d2194168 SimplifyLibCalls: Remove incorrect optimization of fabs
fabs(x * x) is not generally safe to assume x is positive if x is a NaN.
This is also less general than it could be, so this will be replaced
with a transformation on the intrinsic.

llvm-svn: 291359
2017-01-07 19:55:12 +00:00
Teresa Johnson 9006d52651 [ThinLTO] Handle conflicting local names gracefully
Summary:
r285871 introduced an assert that was overly aggressive in the case
of a same-named local in different same-named files (in different
directories), where the source name and therefore the GUID ended up
the same because the files were compiled in their own directory without
any leading path. Change the handling in the promotion logic to get
the summary for the version in that module.

This also exposed an issue where we are not always importing the
right copy, which is a performance not correctness issue (because
the renaming is based on the module hash which must be different,
see the bug report for details). I will fix that as a follow-on.

Fixes PR31561.

Reviewers: mehdi_amini

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D28411

llvm-svn: 291304
2017-01-06 23:38:41 +00:00
Teresa Johnson 2b60384581 [ThinLTO] Add parenthesis as per build warning
Fixes a warning about "||" and "&&" due to r291108.

llvm-svn: 291119
2017-01-05 15:10:10 +00:00
Teresa Johnson 519465b993 [ThinLTO] Subsume all importing checks into a single flag
Summary:
This adds a new summary flag NotEligibleToImport that subsumes
several existing flags (NoRename, HasInlineAsmMaybeReferencingInternal
and IsNotViableToInline). It also subsumes the checking of references
on the summary that was being done during the thin link by
eligibleForImport() for each candidate. It is much more efficient to
do that checking once during the per-module summary build and record
it in the summary.

Reviewers: mehdi_amini

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D28169

llvm-svn: 291108
2017-01-05 14:32:16 +00:00
Robert Lougher 5bf0416f45 Reapply "[SimplifyCFG] In sinkLastInstruction correctly set debugloc of common inst"
This reapplies r289828 (reverted in r289833 as it broke the address sanitizer).  The
debugloc is now only set when the instruction is not a call, as this causes the
verifier to assert (the inliner requires an inlinable callsite to have a debug loc
if the caller and callee have debug info).

Original commit message:

Simplify CFG will try to sink the last instruction in a series of basic blocks,
creating a "common" instruction in the successor block (sinkLastInstruction).
When it does this, the debug location of the single instruction should be the
merged debug locations of the commoned instructions.

Original review: https://reviews.llvm.org/D27590

llvm-svn: 290973
2017-01-04 17:40:32 +00:00
Xin Tong 2940231ff0 Make sure total loop body weight is preserved in loop peeling
Summary:
Regardless how the loop body weight is distributed, we should preserve
total loop body weight. i.e. we should have same weight reaching the body of the loop
or its duplicates in peeled and unpeeled case.

Reviewers: mkuper, davidxl, anemet

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D28179

llvm-svn: 290833
2017-01-02 20:27:23 +00:00