Commit Graph

20907 Commits

Author SHA1 Message Date
Sanjay Patel 35b1c2d19d [InstCombine] narrow width of rotate patterns, part 3
This is a longer variant for the pattern handled in
rL346713 
This one includes zexts. 

Eventually, we should canonicalize all rotate patterns 
to the funnel shift intrinsics, but we need a bit more
infrastructure to make sure the vectorizers handle those
intrinsics as well as the shift+logic ops.

https://rise4fun.com/Alive/FMn

Name: narrow rotateright
  %neg = sub i8 0, %shamt
  %rshamt = and i8 %shamt, 7
  %rshamtconv = zext i8 %rshamt to i32
  %lshamt = and i8 %neg, 7
  %lshamtconv = zext i8 %lshamt to i32
  %conv = zext i8 %x to i32
  %shr = lshr i32 %conv, %rshamtconv
  %shl = shl i32 %conv, %lshamtconv
  %or = or i32 %shl, %shr
  %r = trunc i32 %or to i8
  =>
  %maskedShAmt2 = and i8 %shamt, 7
  %negShAmt2 = sub i8 0, %shamt
  %maskedNegShAmt2 = and i8 %negShAmt2, 7
  %shl2 = lshr i8 %x, %maskedShAmt2
  %shr2 = shl i8 %x, %maskedNegShAmt2
  %r = or i8 %shl2, %shr2
llvm-svn: 346716
2018-11-12 22:52:25 +00:00
Sanjay Patel 98e427ccf2 [InstCombine] narrow width of rotate patterns, part 2 (PR39624)
The sub-pattern for the shift amount in a rotate can take on
several different forms, and there's apparently no way to
canonicalize those without seeing the entire rotate sequence.

This is the form noted in:
https://bugs.llvm.org/show_bug.cgi?id=39624

https://rise4fun.com/Alive/qnT

  %zx = zext i8 %x to i32
  %maskedShAmt = and i32 %shAmt, 7
  %shl = shl i32 %zx, %maskedShAmt
  %negShAmt = sub i32 0, %shAmt
  %maskedNegShAmt = and i32 %negShAmt, 7
  %shr = lshr i32 %zx, %maskedNegShAmt
  %rot = or i32 %shl, %shr
  %r = trunc i32 %rot to i8
  =>
  %truncShAmt = trunc i32 %shAmt to i8
  %maskedShAmt2 = and i8 %truncShAmt, 7
  %shl2 = shl i8 %x, %maskedShAmt2
  %negShAmt2 = sub i8 0, %truncShAmt
  %maskedNegShAmt2 = and i8 %negShAmt2, 7
  %shr2 = lshr i8 %x, %maskedNegShAmt2
  %r = or i8 %shl2, %shr2

llvm-svn: 346713
2018-11-12 22:11:09 +00:00
Sanjay Patel ceab2329b6 [InstCombine] refactor code for matching shift amount of a rotate; NFC
As shown in existing test cases and with:
https://bugs.llvm.org/show_bug.cgi?id=39624
...we're missing at least 2 more patterns for rotate narrowing.

llvm-svn: 346711
2018-11-12 22:00:00 +00:00
Philip Reames b8d8db30ea [GC][InstCombine] Fix a potential iteration issue
Noticed via inspection.  Appears to be largely innocious in practice, but slight code change could have resulted in either visit order dependent missed optimizations or infinite loops.  May be a minor compile time problem today.

llvm-svn: 346698
2018-11-12 20:00:53 +00:00
Simon Pilgrim 631f2bf51e [CostModel] Add more realistic SK_ExtractSubvector generic costs.
Instead of defaulting to a cost = 1, expand to element extract/insert like we do for other shuffles.

This exposes an issue in LoopVectorize which could call SK_ExtractSubvector with a scalar subvector type.

llvm-svn: 346656
2018-11-12 14:25:23 +00:00
Max Kazantsev 7d49a3a816 [LICM] Hoist guards from non-header blocks
This patch relaxes overconservative checks on whether or not we could write
memory before we execute an instruction. This allows us to hoist guards out of
loops even if they are not in the header block.

Differential Revision: https://reviews.llvm.org/D50891
Reviewed By: fedor.sergeev

llvm-svn: 346643
2018-11-12 09:29:58 +00:00
Calixte Denizet c6fabeac11 [GCOV] Add options to filter files which must be instrumented.
Summary:
When making code coverage, a lot of files (like the ones coming from /usr/include) are removed when post-processing gcno/gcda so finally they doen't need to be instrumented nor to appear in gcno/gcda.
The goal of the patch is to be able to filter the files we want to instrument, there are several advantages to do that:
- improve speed (no overhead due to instrumentation on files we don't care)
- reduce gcno/gcda size
- it gives the possibility to easily instrument only few files (e.g. ones modified in a patch) without changing the build system
- need to accept this patch to be enabled in clang: https://reviews.llvm.org/D52034

Reviewers: marco-c, vsk

Reviewed By: marco-c

Subscribers: llvm-commits, sylvestre.ledru

Differential Revision: https://reviews.llvm.org/D52033

llvm-svn: 346641
2018-11-12 09:01:43 +00:00
Florian Hahn 9026d4ee9b [IPSCCP,PM] Preserve PDT in the new pass manager.
Reviewers: kuhar, chandlerc, NutshellySima, brzycki

Reviewed By: NutshellySima, brzycki

Differential Revision: https://reviews.llvm.org/D54317

llvm-svn: 346618
2018-11-11 20:22:45 +00:00
Sanjay Patel 4a12aa9791 [InstCombine] simplify code for merging stores; NFCI
llvm-svn: 346596
2018-11-10 20:29:25 +00:00
Eugene Leviant be8d19967a [ThinLTO] Internalize readonly globals
This patch allows internalising globals if all accesses to them
(from live functions) are from non-volatile load instructions

Differential revision: https://reviews.llvm.org/D49362

llvm-svn: 346584
2018-11-10 08:31:21 +00:00
Eli Friedman 15930bf352 [JumpThreading] Fix exponential time algorithm computing known values.
ComputeValueKnownInPredecessors has a "visited" set to prevent infinite
loops, since a value can be visited more than once.  However, the
implementation didn't prevent the algorithm from taking exponential
time. Instead of removing elements from the RecursionSet one at a time,
we should keep around the whole set until
ComputeValueKnownInPredecessors finishes, then discard it.

The testcase is synthetic because I was having trouble effectively
reducing the original.  But it's basically the same idea.

Instead of failing, we could theoretically cache the result instead.
But I don't think it would help substantially in practice.

Differential Revision: https://reviews.llvm.org/D54239

llvm-svn: 346562
2018-11-09 22:35:26 +00:00
Florian Hahn 9f878e9bae Revert r346483: [CallSiteSplitting] Only record conditions up to the IDom(call site).
This cause a failure with EXPENSIVE_CHECKS

llvm-svn: 346492
2018-11-09 13:28:58 +00:00
Florian Hahn a1062f4b68 [IPSCCP,PM] Preserve DT in the new pass manager.
After D45330, Dominators are required for IPSCCP and can be preserved.

This patch preserves DominatorTreeAnalysis in the new pass manager. AFAIK the legacy pass manager cannot preserve function analysis required by a module analysis.

Reviewers: davide, dberlin, chandlerc, efriedma, kuhar, NutshellySima

Reviewed By: chandlerc, kuhar, NutshellySima

Differential Revision: https://reviews.llvm.org/D47259

llvm-svn: 346486
2018-11-09 11:52:27 +00:00
Florian Hahn 52578f95c9 [CallSiteSplitting] Only record conditions up to the IDom(call site).
We can stop recording conditions once we reached the immediate dominator
for the block containing the call site. Conditions in predecessors of the
that node will be the same for all paths to the call site and splitting
is not beneficial.

This patch makes CallSiteSplitting dependent on the DT anlysis. because
the immediate dominators seem to be the easiest way of finding the node
to stop at.

I had to update some exiting tests, because they were checking for
conditions that were true/false on all paths to the call site. Those
should now be handled by instcombine/ipsccp.

Reviewers: davide, junbuml

Reviewed By: junbuml

Differential Revision: https://reviews.llvm.org/D44627

llvm-svn: 346483
2018-11-09 10:23:46 +00:00
Carlos Alberto Enciso fa9cf89734 [DebugInfo][Dexter] Unreachable line stepped onto after SimplifyCFG.
In SimplifyCFG when given a conditional branch that goes to BB1 and BB2, the hoisted common terminator instruction in the two blocks, caused debug line records associated with subsequent select instructions to become ambiguous. It causes the debugger to display unreachable source lines.

Differential Revision: https://reviews.llvm.org/D53390

llvm-svn: 346481
2018-11-09 09:42:10 +00:00
Max Kazantsev 9883d1e1a7 [NFC] Add utility function for SafetyInfo updates for moveBefore
llvm-svn: 346472
2018-11-09 05:39:04 +00:00
Florian Hahn a684a99441 [LoopInterchange] Support reductions across inner and outer loop.
This patch adds logic to detect reductions across the inner and outer
loop by following the incoming values of PHI nodes in the outer loop. If
the incoming values take part in a reduction in the inner loop or come
from outside the outer loop, we found a reduction spanning across inner
and outer loop.

With this change, ~10% more loops are interchanged in the LLVM
test-suite + SPEC2006.

Fixes https://bugs.llvm.org/show_bug.cgi?id=30472

Reviewers: mcrosier, efriedma, karthikthecool, davide, hfinkel, dmgreen

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D43245

llvm-svn: 346438
2018-11-08 20:44:19 +00:00
Pirama Arumuga Nainar e61652a384 [LTO] Drop non-prevailing definitions only if linkage is not local or appending
Summary:
This fixes PR 37422

In ELF, non-weak symbols can also be non-prevailing.  In this particular
PR, the __llvm_profile_* symbols are non-prevailing but weren't getting
dropped - causing multiply-defined errors with lld.

Also add a test, strong_non_prevailing.ll, to ensure that multiple
copies of a strong symbol are dropped.

To fix the test regressions exposed by this fix,
- do not mark prevailing copies for symbols with 'appending' linkage.
There's no one prevailing copy for such symbols.
- fix the prevailing version in dead-strip-fulllto.ll
- explicitly pass exported symbols to llvm-lto in fumcimport.ll and
funcimport_var.ll

Reviewers: tejohnson, pcc

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

Differential Revision: https://reviews.llvm.org/D54125

llvm-svn: 346436
2018-11-08 20:10:07 +00:00
Tom Stellard 28d662164d InstCombine: Avoid introducing poison values when lowering llvm.amdgcn.[us]bfe
Summary:
When the 3rd argument to these intrinsics is zero, lowering them
to shift instructions produces poison values, since we end up with
shift amounts equal to the number of bits in the shifted value.  This
means we can only lower these intrinsics if we can prove that the
3rd argument is not zero.

Reviewers: arsenm

Reviewed By: arsenm

Subscribers: bnieuwenhuizen, jvesely, wdng, nhaehnle, llvm-commits

Differential Revision: https://reviews.llvm.org/D53739

llvm-svn: 346422
2018-11-08 17:57:57 +00:00
Vedant Kumar d6699423f1 [CodeExtractor] Mark functions noreturn when applicable
This eliminates the outlining penalty for llvm.trap/unreachable, because
callers no longer have to emit cleanup/ret instructions after calling an
outlined `noreturn` function.

rdar://45523626

llvm-svn: 346421
2018-11-08 17:57:09 +00:00
Max Kazantsev 266c087b9d Return "[IndVars] Smart hard uses detection"
The patch has been reverted because it ended up prohibiting propagation
of a constant to exit value. For such values, we should skip all checks
related to hard uses because propagating a constant is always profitable.

Differential Revision: https://reviews.llvm.org/D53691

llvm-svn: 346397
2018-11-08 11:54:35 +00:00
Gil Rapaport 7b88bab386 [LSR] Combine unfolded offset into invariant register
LSR reassociates constants as unfolded offsets when the constants fit as
immediate add operands, which currently prevents such constants from being
combined later with loop invariant registers.
This patch modifies GenerateCombinations() to generate a second formula which
includes the unfolded offset in the combined loop-invariant register.

This commit fixes a bug in the original patch (committed at r345114, reverted
at r345123).

Differential Revision: https://reviews.llvm.org/D51861

llvm-svn: 346390
2018-11-08 09:01:19 +00:00
whitequark 73cb978495 [MergeFuncs] Improve ordering of equal functions
Summary:
MergeFunctions currently tries to process strong functions before
weak functions, because weak functions can simply call strong
functions, while a strong/weak function cannot call a weak function
(a backing strong function is needed).

This patch additionally tries to process external functions before
local functions, because we definitely have to keep the external
function, but may be able to drop the local one (and definitely
can if it is also unnamed_addr).

Unfortunately, this exposes an existing bug in the implementation:
The FnTree and FNodesInTree structures can currently go out of
sync in the case where two weak functions are merged, because the
function in FnTree/FNodesInTree is RAUWed. This leaves it behind in
FnTree (this is intended, as it is the strong backing function which
should be used for further merges), while it is replaced in
FNodesInTree (this is not intended).

This is fixed by switching FNodesInTree from using a ValueMap to
using a DenseMap of AssertingVH.

This exposes another minor issue: Currently FNodesInTree is not
cleared after MergeFunctions finishes running. Currently, this is
potentially dangerous (e.g. if something else wants to RAUW a function
with a non-function), but at the very least it is unnecessary/inefficient.
After the change to use AssertingVH it becomes more problematic,
because there are certainly passes that remove functions.

This issue is fixed by clearing FNodesInTree at the end of the pass.

Reviewers: jfb, whitequark

Reviewed By: whitequark

Subscribers: rkruppe, llvm-commits

Differential Revision: https://reviews.llvm.org/D53271

llvm-svn: 346386
2018-11-08 03:58:01 +00:00
whitequark 3580ac6125 [MergeFuncs] Call removeUsers() prior to unnamed_addr RAUW
Summary:
For unnamed_addr functions we RAUW instead of only replacing direct callers. However, functions in which replacements were performed currently are not added back to the worklist, resulting in missed merging opportunities.

Fix this by calling removeUsers() prior to RAUW.

Reviewers: jfb, whitequark

Reviewed By: whitequark

Subscribers: rkruppe, llvm-commits

Differential Revision: https://reviews.llvm.org/D53262

llvm-svn: 346385
2018-11-08 03:57:55 +00:00
Reid Kleckner b41b372171 [sancov] Put .SCOV* sections into the right comdat groups on COFF
Avoids linker errors about relocations against discarded sections.

This was uncovered during the Chromium clang roll here:
https://chromium-review.googlesource.com/c/chromium/src/+/1321863#message-717516acfcf829176f6a2f50980f7a4bdd66469a

After this change, Chromium's libGLESv2 links successfully for me.

Reviewers: metzman, hans, morehouse

Differential Revision: https://reviews.llvm.org/D54232

llvm-svn: 346381
2018-11-08 00:57:33 +00:00
Rong Xu fb4bcc452c [PGO] Exit early if all count values are zero
If all the edge counts for a function are zero, skip count population and
annotation, as nothing will happen. This can save some compile time.

Differential Revision: https://reviews.llvm.org/D54212

llvm-svn: 346370
2018-11-07 23:51:20 +00:00
Fedor Sergeev f9a02a7006 [SimpleLoopUnswitch] partial unswitch needs to be careful when replacing invariants with constants
When partial unswitch operates on multiple conditions at once, .e.g:
   if (Cond1 || Cond2 || NonInv) ...

it should infer (and replace) values for individual conditions only on one
side of unswitch and not another.

More precisely only these derivations hold true:
   (Cond1 || Cond2) == false  =>  Cond1 == Cond2 == false
   (Cond1 && Cond2) == true   =>  Cond1 == Cond2 == true

By the way we organize unswitching it means only replacing on "continue" blocks
and never on "unswitched" ones. Since trivial unswitch does not have "unswitched"
blocks it does not have this problem.

Fixes PR 39568.

Reviewers: chandlerc, asbirlea
Differential Revision: https://reviews.llvm.org/D54211

llvm-svn: 346350
2018-11-07 20:05:11 +00:00
Mandeep Singh Grang d47d188b6f [LoopSink] Do not sink instructions into non-cold blocks
Summary: This fixes PR39570.

Reviewers: danielcdh, rnk, bkramer

Reviewed By: rnk

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D54181

llvm-svn: 346337
2018-11-07 18:26:24 +00:00
Florian Hahn ac86038b40 [NewGVN] Make sure we do not add a user to itself.
If we simplify an instruction to itself, we do not need to add a user to
itself. For congruence classes with a defining expression, we already
use a similar logic.

Fixes PR38259.

Reviewers: davide, efriedma, mcrosier

Reviewed By: davide

Differential Revision: https://reviews.llvm.org/D51168

llvm-svn: 346335
2018-11-07 17:20:07 +00:00
Sanjay Patel 57a08b3343 [InstCombine] propagate FMF for fcmp+fabs folds
By morphing the instruction rather than deleting and creating a new one,
we retain fast-math-flags and potentially other metadata (profile info?).

llvm-svn: 346331
2018-11-07 16:15:01 +00:00
Sanjay Patel bb521e63af [InstCombine] peek through fabs() when checking isnan()
That should be the end of the missing cases for this fold.
See earlier patches in this series:
rL346321
rL346324

llvm-svn: 346327
2018-11-07 15:44:26 +00:00
Sanjay Patel fa5f146872 [InstCombine] add folds for fcmp Pred fabs(X), 0.0
Similar to rL346321, we had folds for the ordered
versions of these compares already, so add the
unordered siblings for completeness.

llvm-svn: 346324
2018-11-07 15:33:03 +00:00
James Y Knight 72f76bf230 Add support for llvm.is.constant intrinsic (PR4898)
This adds the llvm-side support for post-inlining evaluation of the
__builtin_constant_p GCC intrinsic.

Also fixed SCCPSolver::visitCallSite to not blow up when seeing a call
to a function where canConstantFoldTo returns true, and one of the
arguments is a struct.

Updated from patch initially by Janusz Sobczak.

Differential Revision: https://reviews.llvm.org/D4276

llvm-svn: 346322
2018-11-07 15:24:12 +00:00
Sanjay Patel 76faf5145d [InstCombine] add fold for fabs(X) u< 0.0
The sibling fold for 'oge' --> 'ord' was already here,
but this half was missing. 

The result of fabs() must be positive or nan, so asking 
if the result is negative or nan is the same as asking 
if the result is nan.

This is another step towards fixing:
https://bugs.llvm.org/show_bug.cgi?id=39475

llvm-svn: 346321
2018-11-07 15:11:32 +00:00
Sanjay Patel de58e93666 fix typos aggressively; NFC
llvm-svn: 346316
2018-11-07 14:35:36 +00:00
Sanjay Patel 7552d0d2e6 [InstCombine] do not shrink switch conditions to illegal types (PR29009)
This patch makes shrinking switch conditions less aggressive which was introduced by:
rL274233

Note that we have 2 new bugs to track potential follow-ups that might have solved PR29009
in different ways:
https://bugs.llvm.org/show_bug.cgi?id=39569
https://bugs.llvm.org/show_bug.cgi?id=39578

Patch by:
@dendibakh (Denis Bakhvalov)

Differential Revision: https://reviews.llvm.org/D54115

llvm-svn: 346315
2018-11-07 14:12:41 +00:00
Calixte Denizet c3bed1e8e6 [GCOV] Flush counters before to avoid counting the execution before fork twice and for exec** functions we must flush before the call
Summary:
This is replacement for patch in https://reviews.llvm.org/D49460.
When we fork, the counters are duplicate as they're and so the values are finally wrong when writing gcda for parent and child.
So just before to fork, we flush the counters and so the parent and the child have new counters set to zero.
For exec** functions, we need to flush before the call to have some data.

Reviewers: vsk, davidxl, marco-c

Reviewed By: marco-c

Subscribers: llvm-commits, sylvestre.ledru, marco-c

Differential Revision: https://reviews.llvm.org/D53593

llvm-svn: 346313
2018-11-07 13:49:17 +00:00
Sanjay Patel d1172a0c20 [IR] add optional parameter for copying IR flags to compare instructions
As shown, this is used to eliminate redundant code in InstCombine,
and there are more cases where we should be using this pattern, but
we're currently unintentionally dropping flags. 

llvm-svn: 346282
2018-11-07 00:00:42 +00:00
Teresa Johnson cb397461e1 [ThinLTO] Split NotEligibleToImport into legality and inlinability flags
Summary:
The NotEligibleToImport flag on the GlobalValueSummary was set if it
isn't legal to import (e.g. because it references unpromotable locals)
and when it can't be inlined (in which case importing is pointless).

I split out the inlinable piece into a separate flag on the
FunctionSummary (doesn't make sense for aliases or global variables),
because in the future we may want to import for reasons other than
inlining.

Reviewers: davidxl

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

Differential Revision: https://reviews.llvm.org/D53345

llvm-svn: 346261
2018-11-06 19:41:35 +00:00
Vedant Kumar 1e209e284f [CodeExtractor] Do not extract calls to eh_typeid_for (PR39545)
The lowering for a call to eh_typeid_for changes when it's moved from
one function to another.

There are several proposals for fixing this issue in llvm.org/PR39545.
Until some solution is in place, do not allow CodeExtractor to extract
calls to eh_typeid_for, as that results in serious miscompilations.

llvm-svn: 346256
2018-11-06 19:06:08 +00:00
Vedant Kumar 09b7aa443d [CodeExtractor] Erase use-without-def debug intrinsics in parent func
When CodeExtractor moves instructions to a new function, debug
intrinsics referring to those instructions within the parent function
become invalid.

This results in the same verifier failure which motivated r344545, about
function-local metadata being used in the wrong function.

llvm-svn: 346255
2018-11-06 19:05:53 +00:00
Sanjay Patel 724014adde [InstCombine] allow vector types for fcmp+fpext fold
llvm-svn: 346245
2018-11-06 17:20:20 +00:00
Sanjay Patel 46bf3922c1 [InstCombine] propagate fast-math-flags when folding fcmp+fpext, part 2
llvm-svn: 346242
2018-11-06 16:45:27 +00:00
Sanjay Patel 7c3ee4da42 [InstCombine] rearrange code for fcmp+fpext; NFCI
llvm-svn: 346241
2018-11-06 16:37:35 +00:00
Sanjay Patel 1b85f00201 [InstCombine] propagate fast-math-flags when folding fcmp+fpext
llvm-svn: 346240
2018-11-06 16:23:03 +00:00
Sanjay Patel 2fd5b0ebfb [InstCombine] propagate fast-math-flags when folding fcmp+fneg, part 2
llvm-svn: 346238
2018-11-06 15:58:57 +00:00
Sanjay Patel 05e70fb978 [InstCombine] reduce code; NFC
llvm-svn: 346235
2018-11-06 15:53:58 +00:00
Sanjay Patel 70282a0501 [InstCombine] propagate fast-math-flags when folding fcmp+fneg
This is another part of solving PR39475:
https://bugs.llvm.org/show_bug.cgi?id=39475

This might be enough to fix that particular issue, but as noted
with the FIXME, we're still dropping FMF on other folds around here.

llvm-svn: 346234
2018-11-06 15:49:45 +00:00
Simon Pilgrim c1da5f757e [InstCombine] Ensure nested shifts are in range (OSS-Fuzz #9880)
llvm-svn: 346225
2018-11-06 11:28:22 +00:00
Max Kazantsev 0042c06e8b [LICM] Remove too conservative IsMustExecute variable
LICM relies on variable `MustExecute` which is conservatively set to `false`
in all non-headers. It is used when we decide whether or not we want to hoist
an instruction or a guard.

For the guards, it might be too conservative to use this variable, we can
instead use a more precise logic from LoopSafetyInfo. Currently it is only NFC
because `IsMemoryNotModified` is also conservatively set to `false` for all
non-headers, and we cannot hoist guards from non-header blocks. However once we
give up using `IsMemoryNotModified` and use a smarter check instead, this will
allow us to hoist guards from all mustexecute non-header blocks.

Differential Revision: https://reviews.llvm.org/D50888
Reveiwed By: fedor.sergeev

llvm-svn: 346204
2018-11-06 04:17:40 +00:00