Commit Graph

21060 Commits

Author SHA1 Message Date
Nikita Popov 14ca9a8355 Revert "[DemandedBits][BDCE] Support vectors of integers"
This reverts commit r348549. Causing assertion failures during
clang build.

llvm-svn: 348558
2018-12-07 00:42:03 +00:00
Nikita Popov cf65b9207b [DemandedBits][BDCE] Support vectors of integers
DemandedBits and BDCE currently only support scalar integers. This
patch extends them to also handle vector integer operations. In this
case bits are not tracked for individual vector elements, instead a
bit is demanded if it is demanded for any of the elements. This matches
the behavior of computeKnownBits in ValueTracking and
SimplifyDemandedBits in InstCombine.

The getDemandedBits() method can now only be called on instructions that
have integer or vector of integer type. Previously it could be called on
any sized instruction (even if it was not particularly useful). The size
of the return value is now always the scalar size in bits (while
previously it was the type size in bits).

Differential Revision: https://reviews.llvm.org/D55297

llvm-svn: 348549
2018-12-06 23:50:32 +00:00
Adrian Prantl fbeeac0e1e Reapply "Adapt gcov to changes in CFE."
This reverts commit r348203 and reapplies D55085 with an additional
GCOV bugfix to make the change NFC for relative file paths in .gcno files.

Thanks to Ilya Biryukov for additional testing!

Original commit message:

    Update Diagnostic handling for changes in CFE.

    The clang frontend no longer emits the current working directory for
    DIFiles containing an absolute path in the filename: and will move the
    common prefix between current working directory and the file into the
    directory: component.

    https://reviews.llvm.org/D55085

llvm-svn: 348512
2018-12-06 18:44:48 +00:00
Alexandros Lamprineas e4c91f5c4c [GVN] Don't perform scalar PRE on GEPs
Partial Redundancy Elimination of GEPs prevents CodeGenPrepare from
sinking the addressing mode computation of memory instructions back
to its uses. The problem comes from the insertion of PHIs, which
confuse CGP and make it bail.

I've autogenerated the check lines of an existing test and added a
store instruction to demonstrate the motivation behind this change.
The store is now using the gep instead of a phi.

Differential Revision: https://reviews.llvm.org/D55009

llvm-svn: 348496
2018-12-06 16:11:58 +00:00
Ilya Biryukov cb5331eb93 Revert "[LoopSimplifyCFG] Delete dead in-loop blocks"
This reverts commit r348457.
The original commit causes clang to crash when doing an instrumented
build with a new pass manager. Reverting to unbreak our integrate.

llvm-svn: 348484
2018-12-06 13:21:01 +00:00
Roman Lebedev 98cb1216a6 [InstCombine] foldICmpWithLowBitMaskedVal(): don't miscompile -1 vector elts
I was finally able to quantify what i thought was missing in the fix,
it was vector constants. If we have a scalar (and %x, -1),
it will be instsimplified before we reach this code,
but if it is a vector, we may still have a -1 element.

Thus, we want to avoid the fold if *at least one* element is -1.
Or in other words, ignoring the undef elements, no sign bits
should be set. Thus, m_NonNegative().

A follow-up for rL348181
https://bugs.llvm.org/show_bug.cgi?id=39861

llvm-svn: 348462
2018-12-06 08:14:24 +00:00
Max Kazantsev 0b1d069d64 [LoopSimplifyCFG] Delete dead in-loop blocks
This patch teaches LoopSimplifyCFG to delete loop blocks that have
become unreachable after terminator folding has been done.

Differential Revision: https://reviews.llvm.org/D54023
Reviewed By: anna

llvm-svn: 348457
2018-12-06 05:45:02 +00:00
Sanjay Patel 998ececef0 [InstCombine] remove dead code from visitExtractElement
Extracting from a splat constant is always handled by InstSimplify.
Move the test for this from InstCombine to InstSimplify to make
sure that stays true.

llvm-svn: 348423
2018-12-05 23:09:33 +00:00
Sanjay Patel 47b3b4b5aa [InstCombine] reduce duplication in visitExtractElementInst; NFC
llvm-svn: 348418
2018-12-05 21:57:51 +00:00
Vedant Kumar 09415a850e [CodeExtractor] Do not marked outlined calls which may resume EH as noreturn
Treat terminators which resume exception propagation as returning instructions
(at least, for the purposes of marking outlined functions `noreturn`). This is
to avoid inserting traps after calls to outlined functions which unwind.

rdar://46129950

llvm-svn: 348404
2018-12-05 19:35:37 +00:00
Christian Bruel 4ead99b3ac Allow norecurse attribute on functions that have debug infos.
Summary: debug intrinsics might be marked norecurse to enable the caller function to be norecurse and optimized if needed. This avoids code gen optimisation differences when -g is used, as in globalOpt.cpp:processInternalGlobal checks.

Reviewers: chandlerc, jmolloy, aprantl

Reviewed By: aprantl

Subscribers: aprantl, llvm-commits

Differential Revision: https://reviews.llvm.org/D55187

llvm-svn: 348381
2018-12-05 16:48:00 +00:00
Sanjay Patel baffae91b2 [InstCombine] simplify icmps with same operands based on dominating cmp
The tests here are based on the motivating cases from D54827.

More background:
1. We don't get these cases in general with SimplifyCFG because the root
   of the pattern match is an icmp, not a branch. I'm not sure how often
   we encounter this pattern vs. the seemingly more likely case with 
   branches, but I don't see evidence to leave the minimal pattern
   unoptimized.

2. This has a chance of increasing compile-time because we're using a
   ValueTracking call to handle the match. The motivating cases could be
   handled with a simpler pair of calls to isImpliedTrueByMatchingCmp/
   isImpliedFalseByMatchingCmp, but I saw that we have a more 
   comprehensive wrapper around those, so we might as well use it here
   unless there's evidence that it's significantly slower.

3. Ideally, we'd handle the fold to constants in InstSimplify, but as
   with the existing code here, we could extend this to handle cases
   where the result is not a constant, but a new combined predicate.
   That would mean splitting the logic across the 2 passes and possibly
   duplicating the pattern-matching cost.

4. As mentioned in D54827, this seems like the kind of thing that should
   be handled in Correlated Value Propagation, but that pass is currently
   limited to dealing with instructions with constant operands, so extending
   this bit of InstCombine is the smallest/easiest way to get these patterns 
   optimized.

llvm-svn: 348367
2018-12-05 15:04:00 +00:00
Alina Sbirlea 0e216854f9 [LICM] *Actually* disable ControlFlowHoisting.
Summary:
The remaining code paths that ControlFlowHoisting introduced that were
not disabled, increased compile time by 3x for some benchmarks.
The time is spent in DominatorTree updates.

Reviewers: john.brawn, mkazantsev

Subscribers: sanjoy, jlebar, llvm-commits

Differential Revision: https://reviews.llvm.org/D55313

llvm-svn: 348345
2018-12-05 10:16:21 +00:00
Vitaly Buka 8076c57fd2 [asan] Add clang flag -fsanitize-address-use-odr-indicator
Reviewers: eugenis, m.ostapenko, ygribov

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D55157

llvm-svn: 348327
2018-12-05 01:44:31 +00:00
Vitaly Buka d6bab09b4b [asan] Split -asan-use-private-alias to -asan-use-odr-indicator
Reviewers: eugenis, m.ostapenko, ygribov

Subscribers: mehdi_amini, kubamracek, hiraditya, steven_wu, dexonsmith, llvm-commits

Differential Revision: https://reviews.llvm.org/D55156

llvm-svn: 348316
2018-12-04 23:17:41 +00:00
Sanjay Patel 3d5bb15a1d [CmpInstAnalysis] fix function signature for ICmp code to predicate; NFC
The old function underspecified the return type, took an unused parameter,
and had a misleading name.

llvm-svn: 348292
2018-12-04 18:53:27 +00:00
Sanjay Patel d23b5ed857 [InstCombine] rearrange foldICmpWithDominatingICmp; NFC
Move it out from under the constant check, reorder
predicates, add comments. This makes it easier to
extend to handle the non-constant case.

llvm-svn: 348284
2018-12-04 17:44:24 +00:00
Ilya Biryukov 449a7f0dbb Revert "Adapt gcov to changes in CFE."
This reverts commit r348203.
Reason: this produces absolute paths in .gcno files, breaking us
internally as we rely on them being consistent with the filenames passed
in the command line.

Also reverts r348157 and r348155 to account for revert of r348154 in
clang repository.

llvm-svn: 348279
2018-12-04 16:30:31 +00:00
Sanjay Patel a40bf9fff7 [InstCombine] add helper for icmp with dominator; NFC
There's a potential small enhancement to this code that could
solve the cases currently under proposal in D54827 via SimplifyCFG.

Whether instcombine should be doing this kind of semi-non-local
analysis in the first place is an open question, but separating
the logic out can only help if/when we decide to move it to a
different pass. 

AFAICT, any proposal to do this in SimplifyCFG could also be seen 
as an overreach + it would be incomplete to start the fold from a 
branch rather than an icmp.

There's another question here about the code for processUGT_ADDCST_ADD().
That part may be completely dead after rL234638 ?

llvm-svn: 348273
2018-12-04 15:35:17 +00:00
Alina Sbirlea 797935f4f1 [SimpleLoopUnswitch] Remove debug dump.
llvm-svn: 348267
2018-12-04 14:43:24 +00:00
Alina Sbirlea a2eebb828e Update MemorySSA in SimpleLoopUnswitch.
Summary:
Teach SimpleLoopUnswitch to preserve MemorySSA.

Subscribers: sanjoy, jlebar, Prazek, george.burgess.iv, llvm-commits

Differential Revision: https://reviews.llvm.org/D47022

llvm-svn: 348263
2018-12-04 14:23:37 +00:00
Vitaly Buka 537cfc0352 [asan] Reduce binary size by using unnamed private aliases
Summary:
--asan-use-private-alias increases binary sizes by 10% or more.
Most of this space was long names of aliases and new symbols.
These symbols are not needed for the ODC check at all.

Reviewers: eugenis

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D55146

llvm-svn: 348221
2018-12-04 00:36:14 +00:00
Vedant Kumar d129569e34 [CodeExtractor] Split PHI nodes with incoming values from outlined region (PR39433)
If a PHI node out of extracted region has multiple incoming values from it,
split this PHI on two parts. First PHI has incomings only from region and
extracts with it (they are placed to the separate basic block that added to the
list of outlined), and incoming values in original PHI are replaced by first
PHI. Similar solution is already used in CodeExtractor for PHIs in entry block
(severSplitPHINodes method). It covers PR39433 bug.

Patch by Sergei Kachkov!

Differential Revision: https://reviews.llvm.org/D55018

llvm-svn: 348205
2018-12-03 22:40:21 +00:00
Adrian Prantl 40eb622325 Adapt gcov to changes in CFE.
The clang frontend no longer emits the current working directory for
DIFiles containing an absolute path in the filename: and will move the
common prefix between current working directory and the file into the
directory: component.

This fixes the GCOV tests in compiler-rt that were broken by the Clang
change.

llvm-svn: 348203
2018-12-03 22:37:48 +00:00
Sanjay Patel 8c65515082 [InstCombine] fix undef propagation bug with shuffle+binop
When we have a shuffle that extends a source vector with undefs
and then do some binop on that, we must make sure that the extra
elements remain undef with that binop if we reverse the order of
the binop and shuffle.

'or' is probably the easiest example to show the bug because
'or C, undef --> -1' (not undef). But there are other 
opcode/constant combinations where this is true as shown by 
the 'shl' test.

llvm-svn: 348191
2018-12-03 21:15:17 +00:00
Roman Lebedev 7bf2fed167 [InstCombine] foldICmpWithLowBitMaskedVal(): disable 2 faulty folds.
These two folds are invalid for this non-constant pattern
when the mask ends up being all-ones:
https://rise4fun.com/Alive/9au
https://rise4fun.com/Alive/UcQM

Fixes https://bugs.llvm.org/show_bug.cgi?id=39861

llvm-svn: 348181
2018-12-03 20:07:58 +00:00
Sanjay Patel f2bda5e43f [InstCombine] rearrange shuffle+binop fold; NFC
This code has a bug dealing with undefs, so we need
to add another escape hatch, so doing some cleanup
ahead of that.

llvm-svn: 348175
2018-12-03 19:53:04 +00:00
Sanjay Patel 472652ef68 [CmpInstAnalysis] fix formatting; NFC
There are potential improvements to the structure of this API
raised by D54994, but remove some cosmetic blemishes before
making any functional changes.

llvm-svn: 348149
2018-12-03 15:48:30 +00:00
Alexander Potapenko 7502e5fc56 [KMSAN] Enable -msan-handle-asm-conservative by default
This change enables conservative assembly instrumentation in KMSAN builds
by default.
It's still possible to disable it with -msan-handle-asm-conservative=0
if something breaks. It's now impossible to enable conservative
instrumentation for userspace builds, but it's not used anyway.

llvm-svn: 348112
2018-12-03 10:15:43 +00:00
Sanjay Patel 7d82d37854 [ValueTracking] add helper function for testing implied condition; NFCI
We were duplicating code around the existing isImpliedCondition() that
checks for a predecessor block/dominating condition, so make that a
wrapper call.

llvm-svn: 348088
2018-12-02 13:26:03 +00:00
Nikita Popov 0c5d6ccbfc [InstCombine] Support ssub.sat canonicalization for non-splats
Extend ssub.sat(X, C) -> sadd.sat(X, -C) canonicalization to also
support non-splat vector constants. This is done by generalizing
the implementation of the isNotMinSignedValue() helper to return
true for constants that are non-splat, but don't contain any
signed min elements.

Differential Revision: https://reviews.llvm.org/D55011

llvm-svn: 348072
2018-12-01 10:58:34 +00:00
Joseph Tremoulet 27b1e3bd4f [Mem2Reg] Fix nondeterministic corner case
Summary:
When mem2reg inserts phi nodes in blocks with unreachable predecessors,
it adds undef operands for those incoming edges.  When there are
multiple such predecessors, the order is currently based on the address
of the BasicBlocks.  This change fixes that by using the BBNumbers in
the sort/search predicates, as is done elsewhere in mem2reg to ensure
determinism.

Also adds a testcase with a bunch of unreachable preds, which
(nodeterministically) fails without the fix.


Reviewers: majnemer

Reviewed By: majnemer

Subscribers: mgrang, llvm-commits

Differential Revision: https://reviews.llvm.org/D55077

llvm-svn: 348024
2018-11-30 19:20:02 +00:00
Alexey Bataev 3689747619 [SLP]PR39774: Update references of the replaced external instructions.
Summary:
An additional fix for PR39774. Need to update the references for the
RedcutionRoot instruction when it is replaced during the vectorization
phase to avoid compiler crash on reduction vectorization.

Reviewers: RKSimon, spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D55017

llvm-svn: 347997
2018-11-30 15:14:20 +00:00
Max Kazantsev 9cf417db78 [LoopSimplifyCFG] Update MemorySSA in terminator folding. PR39783
Terminator folding transform lacks MemorySSA update for memory Phis,
while they exist within MemorySSA analysis. They need exactly the same
type of updates as regular Phis. Failing to update them properly ends up
with inconsistent MemorySSA and manifests in various assertion failures.

This patch adds Memory Phi updates to this transform.

Thanks to @jonpa for finding this!

Differential Revision: https://reviews.llvm.org/D55050
Reviewed By: asbirlea

llvm-svn: 347979
2018-11-30 10:06:23 +00:00
David Stuttard c6603861d8 Revert r347871 "Fix: Add support for TFE/LWE in image intrinsic"
Also revert fix r347876

One of the buildbots was reporting a failure in some relevant tests that I can't
repro or explain at present, so reverting until I can isolate.

llvm-svn: 347911
2018-11-29 20:14:17 +00:00
Sanjay Patel d802270808 [InstSimplify] fold select with implied condition
This is an almost direct move of the functionality from InstCombine to 
InstSimplify. There's no reason not to do this in InstSimplify because 
we never create a new value with this transform.

(There's a question of whether any dominance-based transform belongs in
either of these passes, but that's a separate issue.)

I've changed 1 of the conditions for the fold (1 of the blocks for the 
branch must be the block we started with) into an assert because I'm not 
sure how that could ever be false.

We need 1 extra check to make sure that the instruction itself is in a
basic block because passes other than InstCombine may be using InstSimplify
as an analysis on values that are not wired up yet.

The 3-way compare changes show that InstCombine has some kind of 
phase-ordering hole. Otherwise, we would have already gotten the intended
final result that we now show here.

llvm-svn: 347896
2018-11-29 18:44:39 +00:00
John Brawn a7eb2c863f [LICM] Reapply r347776 "Make LICM able to hoist phis" with fix
This commit caused a large compile-time slowdown in some cases when NDEBUG is
off due to the dominator tree verification it added. Fix this by only doing
dominator tree and loop info verification when something has been hoisted.

Differential Revision: https://reviews.llvm.org/D52827

llvm-svn: 347889
2018-11-29 17:10:00 +00:00
Teresa Johnson 93f9996278 [ThinLTO] Import local variables from the same module as caller
Summary:
We can sometimes end up with multiple copies of a local variable that
have the same GUID in the index. This happens when there are local
variables with the same name that are in different source files having the
same name/path at compile time (but compiled into different bitcode objects).

In this case make sure we import the copy in the caller's module.
This enables importing both of the variables having the same GUID
(but which will have different promoted names since the module paths,
and therefore the module hashes, will be distinct).

Importing the wrong copy is particularly problematic for read only
variables, since we must import them as a local copy whenever
referenced. Otherwise we get undefs at link time.

Note that the llvm-lto.cpp and ThinLTOCodeGenerator changes are needed
for testing the distributed index case via clang, which will be sent as
a separate clang-side patch shortly. We were previously not doing the
dead code/read only computation before computing imports when testing
distributed index generation (like it was for testing importing and
other ThinLTO mechanisms alone).

Reviewers: evgeny777

Subscribers: mehdi_amini, inglorion, eraman, steven_wu, dexonsmith, dang, llvm-commits

Differential Revision: https://reviews.llvm.org/D55047

llvm-svn: 347886
2018-11-29 17:02:42 +00:00
Joseph Tremoulet 926ee459c4 [CallSiteSplitting] Report edge deletion to DomTreeUpdater
Summary:
When splitting musttail calls, the split blocks' original terminators
get removed; inform the DTU when this happens.

Also add a testcase that fails an assertion in the DTU without this fix.


Reviewers: fhahn, junbuml

Reviewed By: fhahn

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D55027

llvm-svn: 347872
2018-11-29 15:27:04 +00:00
David Stuttard de02e4b1cc Add support for TFE/LWE in image intrinsics
TFE and LWE support requires extra result registers that are written in the
event of a failure in order to detect that failure case.
The specific use-case that initiated these changes is sparse texture support.

This means that if image intrinsics are used with either option turned on, the
programmer must ensure that the return type can contain all of the expected
results. This can result in redundant registers since the vector size must be a
power-of-2.

This change takes roughly 6 parts:
1. Modify the instruction defs in tablegen to add new instruction variants that
can accomodate the extra return values.
2. Updates to lowerImage in SIISelLowering.cpp to accomodate setting TFE or LWE
(where the bulk of the work for these instruction types is now done)
3. Extra verification code to catch cases where intrinsics have been used but
insufficient return registers are used.
4. Modification to the adjustWritemask optimisation to account for TFE/LWE being
enabled (requires extra registers to be maintained for error return value).
5. An extra pass to zero initialize the error value return - this is because if
the error does not occur, the register is not written and thus must be zeroed
before use. Also added a new (on by default) option to ensure ALL return values
are zero-initialized that is required for sparse texture support.
6. Disable the inst_combine optimization in the presence of tfe/lwe (later TODO
for this to re-enable and handle correctly).

There's an additional fix now to avoid a dmask=0

For an image intrinsic with tfe where all result channels except tfe
were unused, I was getting an image instruction with dmask=0 and only a
single vgpr result for tfe. That is incorrect because the hardware
assumes there is at least one vgpr result, plus the one for tfe.

Fixed by forcing dmask to 1, which gives the desired two vgpr result
with tfe in the second one.

The TFE or LWE result is returned from the intrinsics using an aggregate
type. Look in the test code provided to see how this works, but in essence IR
code to invoke the intrinsic looks as follows:

%v = call {<4 x float>,i32} @llvm.amdgcn.image.load.1d.v4f32i32.i32(i32 15,
                                      i32 %s, <8 x i32> %rsrc, i32 1, i32 0)
%v.vec = extractvalue {<4 x float>, i32} %v, 0
%v.err = extractvalue {<4 x float>, i32} %v, 1

Differential revision: https://reviews.llvm.org/D48826

Change-Id: If222bc03642e76cf98059a6bef5d5bffeda38dda
llvm-svn: 347871
2018-11-29 15:21:13 +00:00
Sanjay Patel 8242c82de4 [CVP] tidy processCmp(); NFC
1. The variables were confusing: 'C' typically refers to a constant, but here it was the Cmp.
2. Formatting violations.
3. Simplify code to return true/false constant.

llvm-svn: 347868
2018-11-29 14:41:21 +00:00
Martin Storsjo bfd1d27585 Revert "[LICM] Enable control flow hoisting by default" and "[LICM] Reapply r347190 "Make LICM able to hoist phis" with fix"
This reverts commits r347776 and r347778.

The first one, r347776, caused significant compile time regressions
for certain input files, see PR39836 for details.

llvm-svn: 347867
2018-11-29 14:39:39 +00:00
Max Kazantsev 24c186ff00 Disable TermFolding in LoopSimplifyCFG until PR39783 is fixed
llvm-svn: 347844
2018-11-29 09:00:19 +00:00
Sam Parker d6ebf0108e [LoopStrengthReduce] ComplexityLimit as an option
Convert ComplexityLimit into a command line value.

Differential Revision: https://reviews.llvm.org/D54899

llvm-svn: 347843
2018-11-29 08:34:22 +00:00
Jeremy Morse 9b4cfa55b1 [DebugInfo] Give inlinable calls DILocs (PR39807)
In PR39807 we incorrectly handle circumstances where calls are common'd
from conditional blocks into the parent BB. Calls that can be inlined
must always have DebugLocs, however we strip them during commoning, which
the IR verifier asserts on.

Fix this by using applyMergedLocation: it will perform the same DebugLoc
stripping of conditional Locs, but will also generate an unknown location
DebugLoc that satisfies the requirement for inlinable calls to always have
locations.

Some of the prior logic for selecting a DebugLoc is now likely redundant;
I'll generate a follow-up to remove it (involves editing more regression
tests).

Differential Revision: https://reviews.llvm.org/D54997

llvm-svn: 347782
2018-11-28 17:58:45 +00:00
John Brawn 4557ffeb63 [LICM] Enable control flow hoisting by default
Differential Revision: https://reviews.llvm.org/D54949

llvm-svn: 347778
2018-11-28 17:23:03 +00:00
John Brawn 31c9769580 [LICM] Reapply r347190 "Make LICM able to hoist phis" with fix
This commit caused failures because it failed to correctly handle cases where
we hoist a phi, then hoist a use of that phi, then have to rehoist that use. We
need to make sure that we rehoist the use to _after_ the hoisted phi, which we
do by always rehoisting to the immediate dominator instead of just rehoisting
everything to the original preheader.

An option is also added to control whether control flow is hoisted, which is
off in this commit but will be turned on in a subsequent commit.

Differential Revision: https://reviews.llvm.org/D52827

llvm-svn: 347776
2018-11-28 17:21:49 +00:00
Nikita Popov 8d63aed459 [InstCombine] Combine saturating add/sub with constant operands
Combine
  sat(sat(X + C1) + C2) -> sat(X + (C1+C2))
and
  sat(sat(X - C1) - C2) -> sat(X - (C1+C2))
if the sign of C1 and C2 matches.

In the unsigned case we can compute C1+C2 with saturating arithmetic,
and InstSimplify will reduce this just to the saturation value. For
the signed case, we cannot perform the simplification if the result
of the addition overflows.

This change is part of https://reviews.llvm.org/D54534.

llvm-svn: 347773
2018-11-28 16:37:15 +00:00
Nikita Popov 42f89989a1 [InstCombine] Canonicalize ssub.sat to sadd.sat
Canonicalize ssub.sat(X, C) to ssub.sat(X, -C) if C is constant and
not signed minimum. This will help further optimizations to apply.

This change is part of https://reviews.llvm.org/D54534.

llvm-svn: 347772
2018-11-28 16:37:09 +00:00
Nikita Popov 78a9295e15 [InstCombine] Use known overflow information for saturating add/sub
If ValueTracking can determine that the add/sub can newer overflow,
replace it with the corresponding nuw/nsw add/sub.

Additionally, for the unsigned case, if ValueTracking determines
that the add/sub always overflows, replace the result with the
saturation value.

This change is part of https://reviews.llvm.org/D54534.

llvm-svn: 347770
2018-11-28 16:36:59 +00:00
Nikita Popov 085d24a8b3 [InstCombine] Canonicalize const arg for saturating adds
If a saturating add intrinsic has one constant argument, make sure
it is on the RHS. This will simplify further transformations.

This change is part of https://reviews.llvm.org/D54534.

llvm-svn: 347769
2018-11-28 16:36:52 +00:00
Xin Tong 53e52e47e8 [ThinLTO] Correct linkonce_any function import linkage. NFC.
Summary:
This is a NFC as we do not import non-odr vague linkage when computing
for import list for a module.

Reviewers: tejohnson, pcc

Subscribers: inglorion, dexonsmith, llvm-commits

Differential Revision: https://reviews.llvm.org/D54928

llvm-svn: 347763
2018-11-28 15:16:35 +00:00
Alexey Bataev 579c2d9d64 [SLP]Fix PR39774: Set ReductionRoot if the original instruction is vectorized.
Summary:
If the original reduction root instruction was vectorized, it might be
removed from the tree. It means that the insertion point may become
invalidated and the whole vectorization of the reduction leads to the
incorrect output result.
The ReductionRoot instruction must be marked as externally used so it
could not be removed. Otherwise it might cause inconsistency with the
cost model and we may end up with too optimistic optimization.

Reviewers: RKSimon, spatel, hfinkel, mkuper

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D54955

llvm-svn: 347759
2018-11-28 14:34:11 +00:00
Florian Hahn fd6ea134f4 [PartialInliner] Make PHIs free in cost computation.
InlineCost also treats them as free and the current implementation
can cause assertion failures if PHI nodes are moved outside the region
from entry BBs to the region.

It also updates the code to use the instructionsWithoutDebug iterator.

Reviewers: davidxl, davide, vsk, graham-yiu-huawei

Reviewed By: davidxl

Differential Revision: https://reviews.llvm.org/D54748

llvm-svn: 347683
2018-11-27 18:17:27 +00:00
Tim Northover 81bff5e6ea InstCombine: add comment explaining malloc deletion. NFC.
I tried to change this, not quite realising the logic behind what we
were doing. Hopefully this comment will help the next person to come
along.

llvm-svn: 347653
2018-11-27 11:08:14 +00:00
Max Kazantsev 70b11c6d31 [LoopSimplifyCFG] Turn on term folding after underlying bug fixed
llvm-svn: 347641
2018-11-27 06:19:42 +00:00
Max Kazantsev c4e4d6449a [LoopSimplifyCFG] Fix corner case with duplicating successors
It fixes a bug that doesn't update Phi inputs of the only live successor that
is in the list of block's successors more than once.

Thanks @uabelho for finding this.

Differential Revision: https://reviews.llvm.org/D54849
Reviewed By: anna

llvm-svn: 347640
2018-11-27 06:17:21 +00:00
Xin Tong 04d49779a1 [ICP] Remove incompatible attributes at indirect-call promoted callsites.
Summary:
Removing ncompatible attributes at indirect-call promoted callsites, not removing it results in
at least a IR verification error.

Reviewers: davidxl, xur, mssimpso

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D54913

llvm-svn: 347605
2018-11-26 22:03:52 +00:00
Sanjay Patel 790af91803 [InstCombine] add helper function to reduce code duplication; NFC
llvm-svn: 347604
2018-11-26 22:00:41 +00:00
Florian Hahn 6615a7132a [IPSCCP] Use input operand instead of OriginalOp for ssa_copy.
OriginalOp of a Predicate refers to the original IR value,
before renaming. While solving in IPSCCP, we have to use
the operand of the ssa_copy instead, to avoid missing
updates for nested conditions on the same IR value.

Fixes PR39772.

llvm-svn: 347524
2018-11-25 16:32:02 +00:00
Nikita Popov 2c779c0e34 [InstCombine] Determine demanded and known bits for funnel shifts
Support funnel shifts in InstCombine demanded bits simplification.
If the shift amount is constant, we can determine both the demanded
bits of the operands, as well as the known bits of the result.

If one of the operands has no demanded bits, it will be replaced
by undef and the funnel shift will be simplified into a simple shift
due to the simplifications added in D54778.

Differential Revision: https://reviews.llvm.org/D54869

llvm-svn: 347515
2018-11-24 19:00:45 +00:00
Nikita Popov 6e81d421e1 [InstCombine] Simplify funnel shift with zero/undef operand to shift
The following simplifications are implemented:

 * `fshl(X, 0, C) -> shl X, C%BW`
 * `fshl(X, undef, C) -> shl X, C%BW` (assuming undef = 0)
 * `fshl(0, X, C) -> lshr X, BW-C%BW`
 * `fshl(undef, X, C) -> lshr X, BW-C%BW` (assuming undef = 0)
 * `fshr(X, 0, C) -> shl X, (BW-C%BW)`
 * `fshr(X, undef, C) -> shl X, BW-C%BW` (assuming undef = 0)
 * `fshr(0, X, C) -> lshr X, C%BW`
 * `fshr(undef, X, C) -> lshr, X, C%BW` (assuming undef = 0)

The simplification is only performed if the shift amount C is constant,
because we can explicitly compute C%BW and BW-C%BW in this case.

Differential Revision: https://reviews.llvm.org/D54778

llvm-svn: 347505
2018-11-23 22:45:08 +00:00
Max Kazantsev e1c2dc27d3 Disable LoopSimplifyCFG terminator folding by default
llvm-svn: 347486
2018-11-23 09:14:53 +00:00
Max Kazantsev cb8e240334 [LoopSimplifyCFG] Don't delete LCSSA Phis
When removing edges, we also update Phi inputs and may end up removing
a Phi if it has only one input. We should not do it for edges that leave the current
loop because these Phis are LCSSA Phis and need to be preserved.

Thanks @dmgreen	for finding this!

Differential Revision: https://reviews.llvm.org/D54841

llvm-svn: 347484
2018-11-23 07:56:47 +00:00
Max Kazantsev b565e6093b [NFC] Assert that all blocks staying in loop are live
llvm-svn: 347458
2018-11-22 12:43:27 +00:00
Max Kazantsev 56a2443024 [NFC] Ensure deterministic order of dead exit blocks
llvm-svn: 347457
2018-11-22 12:33:41 +00:00
Max Kazantsev d9f59f8c80 [NFC] Simplify code by using standard exit blocks collection
llvm-svn: 347454
2018-11-22 10:48:30 +00:00
Fedor Sergeev 59246b6bfe [PM] correcting return value for new-pass-manager version of Scalarizer
Obvious mistake missed during D54695 review.

llvm-svn: 347432
2018-11-21 22:01:19 +00:00
Nikita Popov 6f54fb0052 [MergeFuncs] Generate alias instead of thunk if possible
The MergeFunctions pass was originally intended to emit aliases
instead of thunks where possible (unnamed_addr). However, for a
long time this functionality was behind a flag hardcoded to false,
bitrotted and was eventually removed in r309313.

Originally the functionality was first disabled in r108417 due to
lack of support for aliases in Mach-O. I believe that this is no
longer the case nowadays, but not really familiar with this area.

In the interest of being conservative, this patch reintroduces the
aliasing functionality behind a default disabled -mergefunc-use-aliases
flag.

Differential Revision: https://reviews.llvm.org/D53285

llvm-svn: 347407
2018-11-21 19:37:19 +00:00
Mikael Holmen b6f76002d9 [PM] Port Scalarizer to the new pass manager.
Patch by: markus (Markus Lavin)

Reviewers: chandlerc, fedor.sergeev

Reviewed By: fedor.sergeev

Subscribers: llvm-commits, Ka-Ka, bjope

Differential Revision: https://reviews.llvm.org/D54695

llvm-svn: 347392
2018-11-21 14:00:17 +00:00
Guozhi Wei c21fba1bab [LoopSink] Add preheader to alias set
This patch fixes PR39695.

The original LoopSink only considers memory alias in loop body. But PR39695 shows that instructions following sink candidate in preheader should also be checked. This is a conservative patch, it simply adds whole preheader block to alias set. It may lose some optimization opportunity, but I think that is very rare because: 1 in the most common case st/ld to the same address, the load should already be optimized away. 2 usually preheader is not very large. 

Differential Revision: https://reviews.llvm.org/D54659

llvm-svn: 347325
2018-11-20 16:49:07 +00:00
Max Kazantsev c04b5307d1 Recommit "[LoopSimplifyCFG] Teach LoopSimplifyCFG to constant-fold branches and switches"
The initial version of patch lacked Phi nodes updates in destinations of removed
edges. This version contains this update and tests on this situation.

Differential Revision: https://reviews.llvm.org/D54021

llvm-svn: 347289
2018-11-20 05:43:32 +00:00
Reid Kleckner 994a8451ba [Transforms] Prefer static and avoid namespaces, NFC
Put 'static' on three functions in an anonymous namespace as per our
coding style.

Remove the 'namespace llvm {}' around the .cpp file and explicitly
declare the free function 'llvm::optimizeGlobalCtorsList' in 'llvm::'.
I prefer this style for free functions because the compiler will error
out if the .h and .cpp files don't agree on the function name or
prototype.

llvm-svn: 347269
2018-11-19 22:19:05 +00:00
Benjamin Kramer fdd9b4fc8f Revert "[LoopSimplifyCFG] Teach LoopSimplifyCFG to constant-fold branches and switches"
This reverts commits r347183 & r347184. Crashes while building libxml.

llvm-svn: 347260
2018-11-19 20:01:20 +00:00
Vedant Kumar 238533ec2e [InstCombine] Set debug loc on `mergeStoreIntoSuccessor` phi
Assigning a merged debug location to the `mergeStoreIntoSuccessor` phi
improves backtrace quality.

Fixes llvm.org/PR38083.

llvm-svn: 347257
2018-11-19 19:55:02 +00:00
Vedant Kumar 4de31bba51 [IR] Add hasNPredecessors, hasNPredecessorsOrMore to BasicBlock
Add methods to BasicBlock which make it easier to efficiently check
whether a block has N (or more) predecessors.

This can be more efficient than using pred_size(), which is a linear
time operation.

We might consider adding similar methods for successors. I haven't done
so in this patch because succ_size() is already O(1).

With this patch applied, I measured a 0.065% compile-time reduction in
user time for running `opt -O3` on the sqlite3 amalgamation (30 trials).
The change in mergeStoreIntoSuccessor alone saves 45 million linked list
iterations in a stage2 Release build of llc.

See llvm.org/PR39702 for a harder but more general way of achieving
similar results.

Differential Revision: https://reviews.llvm.org/D54686

llvm-svn: 347256
2018-11-19 19:54:27 +00:00
Benjamin Kramer 2cad359c91 Revert "[LICM] Make LICM able to hoist phis"
This reverts commit r347190.

llvm-svn: 347225
2018-11-19 16:51:57 +00:00
Anna Thomas 5e9215f02b [LV] Avoid vectorizing unsafe dependencies in uniform address
Summary:
Currently, when vectorizing stores to uniform addresses, the only
instance we prevent vectorization is if there are multiple stores to the
same uniform address causing an unsafe dependency.
This patch teaches LAA to avoid vectorizing loops that have an unsafe
cross-iteration dependency between a load and a store to the same uniform address.

Fixes PR39653.

Reviewers: Ayal, efriedma

Subscribers: rkruppe, llvm-commits

Differential Revision: https://reviews.llvm.org/D54538

llvm-svn: 347220
2018-11-19 15:39:59 +00:00
John Brawn 12c046fba0 [LICM] Make LICM able to hoist phis
The general approach taken is to make note of loop invariant branches, then when
we see something conditional on that branch, such as a phi, we create a copy of
the branch and (empty versions of) its successors and hoist using that.

This has no impact by itself that I've been able to see, as LICM typically
doesn't see such phis as they will have been converted into selects by the time
LICM is run, but once we start doing phi-to-select conversion later it will be
important.

Differential Revision: https://reviews.llvm.org/D52827

llvm-svn: 347190
2018-11-19 11:31:24 +00:00
Max Kazantsev 8e3e33d138 [LoopSimplifyCFG] Teach LoopSimplifyCFG to constant-fold branches and switches
This patch introduces infrastructure and the simplest case for constant-folding
of branch and switch instructions within loop into unconditional branches.
It is useful as a cleanup for such passes as loop unswitching that sometimes
produce such branches.

Only the simplest case supported in this patch: after the folding, no block
should become dead or stop being part of the loop. Support for more
sophisticated cases will go separately in follow-up patches.

Differential Revision: https://reviews.llvm.org/D54021
Reviewed By: anna

llvm-svn: 347183
2018-11-19 05:54:38 +00:00
Vedant Kumar e7b789b529 [ProfileSummary] Standardize methods and fix comment
Every Analysis pass has a get method that returns a reference of the Result of
the Analysis, for example, BlockFrequencyInfo
&BlockFrequencyInfoWrapperPass::getBFI().  I believe that
ProfileSummaryInfo::getPSI() is the only exception to that, as it was returning
a pointer.

Another change is renaming isHotBB and isColdBB to isHotBlock and isColdBlock,
respectively.  Most methods use BB as the argument of variable names while
methods usually refer to Basic Blocks as Blocks, instead of BB.  For example,
Function::getEntryBlock, Loop:getExitBlock, etc.

I also fixed one of the comments.

Patch by Rodrigo Caetano Rocha!

Differential Revision: https://reviews.llvm.org/D54669

llvm-svn: 347182
2018-11-19 05:23:16 +00:00
Vedant Kumar 35f504c113 [CorrelatedValuePropagation] Preserve debug locations (PR38178)
Fix all of the missing debug location errors in CVP found by debugify.

This includes the missing-location-after-udiv-truncation case described
in llvm.org/PR38178.

llvm-svn: 347147
2018-11-18 00:29:58 +00:00
Fangrui Song 7570932977 Use llvm::copy. NFC
llvm-svn: 347126
2018-11-17 01:44:25 +00:00
Fedor Sergeev 2e3e224e71 [SimpleLoopUnswitch] adding cost multiplier to cap exponential unswitch with
We need to control exponential behavior of loop-unswitch so we do not get
run-away compilation.

Suggested solution is to introduce a multiplier for an unswitch cost that
makes cost prohibitive as soon as there are too many candidates and too
many sibling loops (meaning we have already started duplicating loops
by unswitching).

It does solve the currently known problem with compile-time degradation
(PR 39544).

Tests are built on top of a recently implemented CHECK-COUNT-<num>
FileCheck directives.

Reviewed By: chandlerc, mkazantsev
Differential Revision: https://reviews.llvm.org/D54223

llvm-svn: 347097
2018-11-16 21:16:43 +00:00
Adrian Prantl 83d87520ed GlobalDCE: Teach isEmptyFunction() to ignore debug intrinsics.
This fixes PR39669.
https://bugs.llvm.org/show_bug.cgi?id=39669

llvm-svn: 347065
2018-11-16 17:47:21 +00:00
Eugene Leviant bf46e7410c [ThinLTO] Internalize readonly globals
An attempt to recommit r346584 after failure on OSX build bot.
Fixed cache key computation in ThinLTOCodeGenerator and added
test case

llvm-svn: 347033
2018-11-16 07:08:00 +00:00
Xin Tong 642c8d3575 [LTO] Load sample profile in LTO link step.
Summary:
Load sample profile in LTO link step.
ThinLTO calls populateModulePassManager to load the profile

Reviewers: tejohnson, davidxl, danielcdh

Subscribers: mehdi_amini, inglorion, steven_wu, dexonsmith, llvm-commits

Differential Revision: https://reviews.llvm.org/D54564

llvm-svn: 346971
2018-11-15 18:06:42 +00:00
Sanjay Patel bc56b2432d [InstCombine] fix rotate narrowing bug for non-pow-2 types
llvm-svn: 346968
2018-11-15 17:19:14 +00:00
Mandeep Singh Grang 0905fc77c1 [InstCombine] Remove a couple of asserts based on incorrect assumptions
Summary:
These asserts are based on the assumption that the order of true/false operands in a select and those in the compare would always be the same.
This fixes PR39595.

Reviewers: craig.topper, spatel, dmgreen

Reviewed By: craig.topper

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D54359

llvm-svn: 346874
2018-11-14 17:55:07 +00:00
Sanjay Patel 6072842770 [InstCombine] fix formatting for matchBSwap(); NFC
We should have a similar function for matching rotate and/or 
funnel shift, so tidy up the related existing call.

llvm-svn: 346871
2018-11-14 16:03:36 +00:00
Florian Hahn 6df11868b5 [VPlan, SLP] Use SmallPtrSet for Candidates.
This slightly improves the candidate handling in getBest().

llvm-svn: 346870
2018-11-14 15:58:40 +00:00
Florian Hahn 02cb67deb9 [VPlan] Remove LLVM_DEBUG from VPlanSlp::dumpBundle.
The caller should take care of only calling it with debug enabled.

llvm-svn: 346860
2018-11-14 13:33:44 +00:00
Florian Hahn 2eca3728ee [VPlan] Update ifdef.
llvm-svn: 346858
2018-11-14 13:21:26 +00:00
Florian Hahn 09e516c54b [VPlan, SLP] Add simple SLP analysis on top of VPlan.
This patch adds an initial implementation of the look-ahead SLP tree
construction described in 'Look-Ahead SLP: Auto-vectorization in the Presence
of Commutative Operations, CGO 2018 by Vasileios Porpodas, Rodrigo C. O. Rocha,
Luís F. W. Góes'.

It returns an SLP tree represented as VPInstructions, with combined
instructions represented as a single, wider VPInstruction.

This initial version does not support instructions with multiple
different users (either inside or outside the SLP tree) or
non-instruction operands; it won't generate any shuffles or
insertelement instructions.

It also just adds the analysis that builds an SLP tree rooted in a set
of stores. It does not include any cost modeling or memory legality
checks. The plan is to integrate it with VPlan based cost modeling, once
available and to only apply it to operations that can be widened.

A follow-up patch will add a support for replacing instructions in a
VPlan with their SLP counter parts.

Reviewers: Ayal, mssimpso, rengolin, mkuper, hfinkel, hsaito, dcaballe, vporpo, RKSimon, ABataev

Reviewed By: rengolin

Differential Revision: https://reviews.llvm.org/D4949

llvm-svn: 346857
2018-11-14 13:11:49 +00:00
Florian Hahn 505091a8f2 Recommit r346483: [CallSiteSplitting] Only record conditions up to the IDom(call site).
The underlying problem causing the expensive-check failure was fixed in
rL346769.

llvm-svn: 346843
2018-11-14 10:04:30 +00:00
Reid Kleckner 41390b47de Revert r346810 "Preserve loop metadata when splitting exit blocks"
It broke the Windows self-host:
http://lab.llvm.org:8011/builders/clang-x64-windows-msvc/builds/1457

llvm-svn: 346823
2018-11-14 01:47:32 +00:00
Sanjay Patel a139564896 [InstCombine] fold funnel shift amount based on demanded bits
The shift amount of a funnel shift is modulo the scalar bitwidth:
http://llvm.org/docs/LangRef.html#llvm-fshl-intrinsic
...so we can use demanded bits analysis on that operand to simplify it
when we have a power-of-2 bitwidth.

This is another step towards canonicalizing {shift/shift/or} to the 
intrinsics in IR.

Differential Revision: https://reviews.llvm.org/D54478

llvm-svn: 346814
2018-11-13 23:27:23 +00:00
Craig Topper 3c87c2a3c5 Preserve loop metadata when splitting exit blocks
LoopUtils.cpp contains a utility that splits an loop exit block, so that the new block contains only edges coming from the loop. In the case of nested loops, the exit path for the inner loop might also be the back-edge of the outer loop. The new block which is inserted on this path, is now a latch for the outer loop, and it needs to hold the loop metadata for the outer loop. (The test case gives a more concrete view of the situation.)

Patch by Chang Lin (clin1)

Differential Revision: https://reviews.llvm.org/D53876

llvm-svn: 346810
2018-11-13 23:06:49 +00:00
Sanjay Patel f8f12272e8 [InstCombine] canonicalize rotate patterns with cmp/select
The cmp+branch variant of this pattern is shown in:
https://bugs.llvm.org/show_bug.cgi?id=34924
...and as discussed there, we probably can't transform
that without a rotate intrinsic. We do have that now
via funnel shift, but we're not quite ready to 
canonicalize IR to that form yet. The case with 'select'
should already be transformed though, so that's this patch.

The sequence with negation followed by masking is what we
use in the backend and partly in clang (though that part 
should be updated).

https://rise4fun.com/Alive/TplC
  %cmp = icmp eq i32 %shamt, 0
  %sub = sub i32 32, %shamt
  %shr = lshr i32 %x, %shamt
  %shl = shl i32 %x, %sub
  %or = or i32 %shr, %shl
  %r = select i1 %cmp, i32 %x, i32 %or
  =>
  %neg = sub i32 0, %shamt
  %masked = and i32 %shamt, 31
  %maskedneg = and i32 %neg, 31
  %shl2 = lshr i32 %x, %masked
  %shr2 = shl i32 %x, %maskedneg
  %r = or i32 %shl2, %shr2

llvm-svn: 346807
2018-11-13 22:47:24 +00:00
Florian Hahn 107d0a8756 [CSP, Cloning] Update DuplicateInstructionsInSplitBetween to use DomTreeUpdater.
This patch updates DuplicateInstructionsInSplitBetween to update a DTU
instead of applying updates to the DT directly.

Given that there only are 2 users, also updated them in this patch to
avoid churn.

I slightly moved the code in CallSiteSplitting around to reduce the
places where we have to pass in DTU. If necessary, I could split those
changes in a separate patch.

This fixes missing DT updates when dealing with musttail calls in
CallSiteSplitting, by using DTU->deleteBB.

Reviewers: junbuml, kuhar, NutshellySima, indutny, brzycki

Reviewed By: NutshellySima

llvm-svn: 346769
2018-11-13 17:54:43 +00:00