Commit Graph

132 Commits

Author SHA1 Message Date
Arthur Eubanks 2df3426fd1 [NewPM] Invalidate AAManager after populating GlobalsAA
GlobalsAA is only created at the beginning of the inliner pipeline.  If
an AAManager is cached from previous passes, it won't get rebuilt to
include the newly created GlobalsAA.

Reviewed By: mtrofin

Differential Revision: https://reviews.llvm.org/D101379
2021-05-03 16:37:32 -07:00
Gulfem Savrun Yeniceri 4423a7a09b [NewPM] Disable RelLookupTableConverter pass in LTO
Relative look table converter pass caused an issue when full lto
is enabled (reported in https://reviews.llvm.org/D94355).
This patch disables that pass from full lto pre-link phase optimization
pipeline until the issue is fixed.

Differential Revision: https://reviews.llvm.org/D101664
2021-04-30 21:23:40 +00:00
Joseph Huber b2ad63d3cf [OpenMP] Add OpenMPOpt as a Module pass
Summary:
This patch registers OpenMPOpt as a Module pass in addition to a CGSCC
pass. This is so certain optimzations that are sensitive to intact
call-sites can happen before inlining. The old `openmpopt` pass name is
changed to `openmp-opt-cgscc` and `openmp-opt` calls the Module pass.
The current module pass only runs a single check but will be expanded in
the future.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D99202
2021-04-20 12:28:58 -04:00
Gulfem Savrun Yeniceri e96df3e531 [Passes] Add relative lookup table converter pass
Lookup tables generate non PIC-friendly code, which requires dynamic relocation as described in:
https://bugs.llvm.org/show_bug.cgi?id=45244

This patch adds a new pass that converts lookup tables to relative lookup tables to make them PIC-friendly.

Differential Revision: https://reviews.llvm.org/D94355
2021-04-13 01:29:41 +00:00
Sanjay Patel 661cc71a1c [PassManager][PhaseOrdering] lower expects before running simplifyCFG
Retry of 330619a3a6 that includes a clang test update.

Original commit message:

If we run passes before lowering llvm.expect intrinsics to metadata,
then those passes have no way to act on the hints provided by llvm.expect.
SimplifyCFG is the known offender, and we made it smarter about profile
metadata in D98898 <https://reviews.llvm.org/D98898>.

In the motivating example from https://llvm.org/PR49336 , this means we
were ignoring the recommended method for a programmer to tell the compiler
that a compare+branch is expensive. This change appears to solve that case -
the metadata survives to the backend, the compare order is as expected in IR,
and the backend does not do anything to reverse it.

We make the same change to the old pass manager to keep things synchronized.

Differential Revision: https://reviews.llvm.org/D100213
2021-04-12 15:07:53 -04:00
Sanjay Patel 23ac9d1e6e Revert "[PassManager][PhaseOrdering] lower expects before running simplifyCFG"
This reverts commit 330619a3a6.
There are clang tests that also need to be updated.
2021-04-12 13:58:54 -04:00
Sanjay Patel 330619a3a6 [PassManager][PhaseOrdering] lower expects before running simplifyCFG
If we run passes before lowering llvm.expect intrinsics to metadata,
then those passes have no way to act on the hints provided by llvm.expect.
SimplifyCFG is the known offender, and we made it smarter about profile
metadata in D98898.

In the motivating example from https://llvm.org/PR49336 , this means we
were ignoring the recommended method for a programmer to tell the compiler
that a compare+branch is expensive. This change appears to solve that case -
the metadata survives to the backend, the compare order is as expected in IR,
and the backend does not do anything to reverse it.

We make the same change to the old pass manager to keep things synchronized.

Differential Revision: https://reviews.llvm.org/D100213
2021-04-12 12:23:31 -04:00
Yevgeny Rouban 39e3e3aa51 [NewPM] Redesign of PreserveCFG Checker
The reason for the NewPM redesign is described in the commit
  cba3e783389a: [NewPM] Disable PreservedCFGChecker ...

The checker introduces an internal custom CFG analysis that tracks
current up-to date CFG snapshot. The analysis is invalidated along
any other CFG related analysis (the key is CFGAnalyses). If the CFG
analysis is not invalidated at a functional pass exit then the checker
asserts that the CFG snapshot taken from this analysis is equals to
a snapshot of the current CFG.

Along the way:
- the function CFG::printDiff() is simplified by removing function
  name calculation. The name is printed by the caller;
- fixed CFG invalidated condition (see CFG::invalidate());
- StandardInstrumentations::registerCallbacks() gets additional
  optional parameter of type FunctionAnalysisManager*, which is
  needed by the checker to get the custom CFG analysis;
- several PM related tests updated to explicitly set
  -verify-cfg-preserved=1 as they need.

This patch is safe to land as the CFGChecker is left switched off
(the options -verify-cfg-preserved is false by default). It will be
switched on by a separate patch to minimize possible reverts.

Reviewed By: skatkov, kuhar

Differential Revision: https://reviews.llvm.org/D91327
2021-04-06 12:35:49 +07:00
Roman Lebedev a26f1bf67e
[PassManager] Run additional LICM before LoopRotate
Loop rotation often has to perform code duplication
from header into preheader, which introduces PHI nodes.

>>! In D99204, @thopre wrote:
>
> With loop peeling, it is important that unnecessary PHIs be avoided or
> it will leads to spurious peeling. One source of such PHIs is loop
> rotation which creates PHIs for invariant loads. Those PHIs are
> particularly problematic since loop peeling is now run as part of simple
> loop unrolling before GVN is run, and are thus a source of spurious
> peeling.
>
> Note that while some of the load can be hoisted and eventually
> eliminated by instruction combine, this is not always possible due to
> alignment issue. In particular, the motivating example [1] was a load
> inside a class instance which cannot be hoisted because the `this'
> pointer has an alignment of 1.
>
> [1] http://lists.llvm.org/pipermail/llvm-dev/attachments/20210312/4ce73c47/attachment.cpp

Now, we could enhance LoopRotate to avoid duplicating code when not needed,
but instead hoist loop-invariant code, but isn't that a code duplication? (*sic*)
We have LICM, and in fact we already run it right after LoopRotation.

We could try to move it to before LoopRotation,
that is basically free from compile-time perspective:
https://llvm-compile-time-tracker.com/compare.php?from=6c93eb4477d88af046b915bc955c03693b2cbb58&to=a4bee6d07732b1184c436da489040b912f0dc271&stat=instructions
But, looking at stats, i think it isn't great that we would no longer do LICM after LoopRotation, in particular:
| statistic name                                   | LoopRotate-LICM | LICM-LoopRotate |     Δ |       % | abs(%) |
| asm-printer.EmittedInsts                         | 9015930         | 9015799         |  -131 |   0.00% |  0.00% |
| indvars.NumElimCmp                               | 3536            | 3544            |     8 |   0.23% |  0.23% |
| indvars.NumElimExt                               | 36725           | 36580           |  -145 |  -0.39% |  0.39% |
| indvars.NumElimIV                                | 1197            | 1187            |   -10 |  -0.84% |  0.84% |
| indvars.NumElimIdentity                          | 143             | 136             |    -7 |  -4.90% |  4.90% |
| indvars.NumElimRem                               | 4               | 5               |     1 |  25.00% | 25.00% |
| indvars.NumLFTR                                  | 29842           | 29890           |    48 |   0.16% |  0.16% |
| indvars.NumReplaced                              | 2293            | 2227            |   -66 |  -2.88% |  2.88% |
| indvars.NumSimplifiedSDiv                        | 6               | 8               |     2 |  33.33% | 33.33% |
| indvars.NumWidened                               | 26438           | 26329           |  -109 |  -0.41% |  0.41% |
| instcount.TotalBlocks                            | 1178338         | 1173840         | -4498 |  -0.38% |  0.38% |
| instcount.TotalFuncs                             | 111825          | 111829          |     4 |   0.00% |  0.00% |
| instcount.TotalInsts                             | 9905442         | 9896139         | -9303 |  -0.09% |  0.09% |
| lcssa.NumLCSSA                                   | 425871          | 423961          | -1910 |  -0.45% |  0.45% |
| licm.NumHoisted                                  | 378357          | 378753          |   396 |   0.10% |  0.10% |
| licm.NumMovedCalls                               | 2193            | 2208            |    15 |   0.68% |  0.68% |
| licm.NumMovedLoads                               | 35899           | 31821           | -4078 | -11.36% | 11.36% |
| licm.NumPromoted                                 | 11178           | 11154           |   -24 |  -0.21% |  0.21% |
| licm.NumSunk                                     | 13359           | 13587           |   228 |   1.71% |  1.71% |
| loop-delete.NumDeleted                           | 8547            | 8402            |  -145 |  -1.70% |  1.70% |
| loop-instsimplify.NumSimplified                  | 12876           | 11890           |  -986 |  -7.66% |  7.66% |
| loop-peel.NumPeeled                              | 1008            | 925             |   -83 |  -8.23% |  8.23% |
| loop-rotate.NumNotRotatedDueToHeaderSize         | 368             | 365             |    -3 |  -0.82% |  0.82% |
| loop-rotate.NumRotated                           | 42015           | 42003           |   -12 |  -0.03% |  0.03% |
| loop-simplifycfg.NumLoopBlocksDeleted            | 240             | 242             |     2 |   0.83% |  0.83% |
| loop-simplifycfg.NumLoopExitsDeleted             | 497             | 20              |  -477 | -95.98% | 95.98% |
| loop-simplifycfg.NumTerminatorsFolded            | 618             | 336             |  -282 | -45.63% | 45.63% |
| loop-unroll.NumCompletelyUnrolled                | 11028           | 11032           |     4 |   0.04% |  0.04% |
| loop-unroll.NumUnrolled                          | 12608           | 12529           |   -79 |  -0.63% |  0.63% |
| mem2reg.NumDeadAlloca                            | 10222           | 10221           |    -1 |  -0.01% |  0.01% |
| mem2reg.NumPHIInsert                             | 192110          | 192106          |    -4 |   0.00% |  0.00% |
| mem2reg.NumSingleStore                           | 637650          | 637643          |    -7 |   0.00% |  0.00% |
| scalar-evolution.NumBruteForceTripCountsComputed | 814             | 812             |    -2 |  -0.25% |  0.25% |
| scalar-evolution.NumTripCountsComputed           | 283108          | 282934          |  -174 |  -0.06% |  0.06% |
| scalar-evolution.NumTripCountsNotComputed        | 106712          | 106718          |     6 |   0.01% |  0.01% |
| simple-loop-unswitch.NumBranches                 | 5178            | 4752            |  -426 |  -8.23% |  8.23% |
| simple-loop-unswitch.NumCostMultiplierSkipped    | 914             | 503             |  -411 | -44.97% | 44.97% |
| simple-loop-unswitch.NumSwitches                 | 20              | 18              |    -2 | -10.00% | 10.00% |
| simple-loop-unswitch.NumTrivial                  | 183             | 95              |   -88 | -48.09% | 48.09% |

... but that actually regresses LICM (-12% `licm.NumMovedLoads`),
loop-simplifycfg (`NumLoopExitsDeleted`, `NumTerminatorsFolded`),
simple-loop-unswitch (`NumTrivial`).

What if we instead have LICM both before and after LoopRotate?
| statistic name                                | LoopRotate-LICM | LICM-LoopRotate-LICM |     Δ |       % | abs(%) |
| asm-printer.EmittedInsts                      | 9015930         | 9014474              | -1456 |  -0.02% |  0.02% |
| indvars.NumElimCmp                            | 3536            | 3546                 |    10 |   0.28% |  0.28% |
| indvars.NumElimExt                            | 36725           | 36681                |   -44 |  -0.12% |  0.12% |
| indvars.NumElimIV                             | 1197            | 1185                 |   -12 |  -1.00% |  1.00% |
| indvars.NumElimIdentity                       | 143             | 146                  |     3 |   2.10% |  2.10% |
| indvars.NumElimRem                            | 4               | 5                    |     1 |  25.00% | 25.00% |
| indvars.NumLFTR                               | 29842           | 29899                |    57 |   0.19% |  0.19% |
| indvars.NumReplaced                           | 2293            | 2299                 |     6 |   0.26% |  0.26% |
| indvars.NumSimplifiedSDiv                     | 6               | 8                    |     2 |  33.33% | 33.33% |
| indvars.NumWidened                            | 26438           | 26404                |   -34 |  -0.13% |  0.13% |
| instcount.TotalBlocks                         | 1178338         | 1173652              | -4686 |  -0.40% |  0.40% |
| instcount.TotalFuncs                          | 111825          | 111829               |     4 |   0.00% |  0.00% |
| instcount.TotalInsts                          | 9905442         | 9895452              | -9990 |  -0.10% |  0.10% |
| lcssa.NumLCSSA                                | 425871          | 425373               |  -498 |  -0.12% |  0.12% |
| licm.NumHoisted                               | 378357          | 383352               |  4995 |   1.32% |  1.32% |
| licm.NumMovedCalls                            | 2193            | 2204                 |    11 |   0.50% |  0.50% |
| licm.NumMovedLoads                            | 35899           | 35755                |  -144 |  -0.40% |  0.40% |
| licm.NumPromoted                              | 11178           | 11163                |   -15 |  -0.13% |  0.13% |
| licm.NumSunk                                  | 13359           | 14321                |   962 |   7.20% |  7.20% |
| loop-delete.NumDeleted                        | 8547            | 8538                 |    -9 |  -0.11% |  0.11% |
| loop-instsimplify.NumSimplified               | 12876           | 12041                |  -835 |  -6.48% |  6.48% |
| loop-peel.NumPeeled                           | 1008            | 924                  |   -84 |  -8.33% |  8.33% |
| loop-rotate.NumNotRotatedDueToHeaderSize      | 368             | 365                  |    -3 |  -0.82% |  0.82% |
| loop-rotate.NumRotated                        | 42015           | 42005                |   -10 |  -0.02% |  0.02% |
| loop-simplifycfg.NumLoopBlocksDeleted         | 240             | 241                  |     1 |   0.42% |  0.42% |
| loop-simplifycfg.NumTerminatorsFolded         | 618             | 619                  |     1 |   0.16% |  0.16% |
| loop-unroll.NumCompletelyUnrolled             | 11028           | 11029                |     1 |   0.01% |  0.01% |
| loop-unroll.NumUnrolled                       | 12608           | 12525                |   -83 |  -0.66% |  0.66% |
| mem2reg.NumPHIInsert                          | 192110          | 192073               |   -37 |  -0.02% |  0.02% |
| mem2reg.NumSingleStore                        | 637650          | 637652               |     2 |   0.00% |  0.00% |
| scalar-evolution.NumTripCountsComputed        | 283108          | 282998               |  -110 |  -0.04% |  0.04% |
| scalar-evolution.NumTripCountsNotComputed     | 106712          | 106691               |   -21 |  -0.02% |  0.02% |
| simple-loop-unswitch.NumBranches              | 5178            | 5185                 |     7 |   0.14% |  0.14% |
| simple-loop-unswitch.NumCostMultiplierSkipped | 914             | 925                  |    11 |   1.20% |  1.20% |
| simple-loop-unswitch.NumTrivial               | 183             | 179                  |    -4 |  -2.19% |  2.19% |
| simple-loop-unswitch.NumBranches              | 5178            | 4752                 |  -426 |  -8.23% |  8.23% |
| simple-loop-unswitch.NumCostMultiplierSkipped | 914             | 503                  |  -411 | -44.97% | 44.97% |
| simple-loop-unswitch.NumSwitches              | 20              | 18                   |    -2 | -10.00% | 10.00% |
| simple-loop-unswitch.NumTrivial               | 183             | 95                   |   -88 | -48.09% | 48.09% |

I.e. we end up with less instructions, less peeling, more LICM activity,
also note how none of those 4 regressions are here. Namely:

| statistic name                                   | LICM-LoopRotate | LICM-LoopRotate-LICM |     Δ |        % |   abs(%) |
| asm-printer.EmittedInsts                         | 9015799         | 9014474              | -1325 |   -0.01% |    0.01% |
| indvars.NumElimCmp                               | 3544            | 3546                 |     2 |    0.06% |    0.06% |
| indvars.NumElimExt                               | 36580           | 36681                |   101 |    0.28% |    0.28% |
| indvars.NumElimIV                                | 1187            | 1185                 |    -2 |   -0.17% |    0.17% |
| indvars.NumElimIdentity                          | 136             | 146                  |    10 |    7.35% |    7.35% |
| indvars.NumLFTR                                  | 29890           | 29899                |     9 |    0.03% |    0.03% |
| indvars.NumReplaced                              | 2227            | 2299                 |    72 |    3.23% |    3.23% |
| indvars.NumWidened                               | 26329           | 26404                |    75 |    0.28% |    0.28% |
| instcount.TotalBlocks                            | 1173840         | 1173652              |  -188 |   -0.02% |    0.02% |
| instcount.TotalInsts                             | 9896139         | 9895452              |  -687 |   -0.01% |    0.01% |
| lcssa.NumLCSSA                                   | 423961          | 425373               |  1412 |    0.33% |    0.33% |
| licm.NumHoisted                                  | 378753          | 383352               |  4599 |    1.21% |    1.21% |
| licm.NumMovedCalls                               | 2208            | 2204                 |    -4 |   -0.18% |    0.18% |
| licm.NumMovedLoads                               | 31821           | 35755                |  3934 |   12.36% |   12.36% |
| licm.NumPromoted                                 | 11154           | 11163                |     9 |    0.08% |    0.08% |
| licm.NumSunk                                     | 13587           | 14321                |   734 |    5.40% |    5.40% |
| loop-delete.NumDeleted                           | 8402            | 8538                 |   136 |    1.62% |    1.62% |
| loop-instsimplify.NumSimplified                  | 11890           | 12041                |   151 |    1.27% |    1.27% |
| loop-peel.NumPeeled                              | 925             | 924                  |    -1 |   -0.11% |    0.11% |
| loop-rotate.NumRotated                           | 42003           | 42005                |     2 |    0.00% |    0.00% |
| loop-simplifycfg.NumLoopBlocksDeleted            | 242             | 241                  |    -1 |   -0.41% |    0.41% |
| loop-simplifycfg.NumLoopExitsDeleted             | 20              | 497                  |   477 | 2385.00% | 2385.00% |
| loop-simplifycfg.NumTerminatorsFolded            | 336             | 619                  |   283 |   84.23% |   84.23% |
| loop-unroll.NumCompletelyUnrolled                | 11032           | 11029                |    -3 |   -0.03% |    0.03% |
| loop-unroll.NumUnrolled                          | 12529           | 12525                |    -4 |   -0.03% |    0.03% |
| mem2reg.NumDeadAlloca                            | 10221           | 10222                |     1 |    0.01% |    0.01% |
| mem2reg.NumPHIInsert                             | 192106          | 192073               |   -33 |   -0.02% |    0.02% |
| mem2reg.NumSingleStore                           | 637643          | 637652               |     9 |    0.00% |    0.00% |
| scalar-evolution.NumBruteForceTripCountsComputed | 812             | 814                  |     2 |    0.25% |    0.25% |
| scalar-evolution.NumTripCountsComputed           | 282934          | 282998               |    64 |    0.02% |    0.02% |
| scalar-evolution.NumTripCountsNotComputed        | 106718          | 106691               |   -27 |   -0.03% |    0.03% |
| simple-loop-unswitch.NumBranches                 | 4752            | 5185                 |   433 |    9.11% |    9.11% |
| simple-loop-unswitch.NumCostMultiplierSkipped    | 503             | 925                  |   422 |   83.90% |   83.90% |
| simple-loop-unswitch.NumSwitches                 | 18              | 20                   |     2 |   11.11% |   11.11% |
| simple-loop-unswitch.NumTrivial                  | 95              | 179                  |    84 |   88.42% |   88.42% |

{F15983613} {F15983615} {F15983616}
(this is vanilla llvm testsuite + rawspeed + darktable)

As an example of the code where early LICM only is bad, see:
https://godbolt.org/z/GzEbacs4K

This does have an observable compile-time regression of +~0.5% geomean
https://llvm-compile-time-tracker.com/compare.php?from=7c5222e4d1a3a14f029e5f614c9aefd0fa505f1e&to=5d81826c3411982ca26e46b9d0aff34c80577664&stat=instructions
but i think that's basically nothing, and there's potential that it might
be avoidable in the future by fixing clang to produce alignment information
on function arguments, thus making the second run unneeded.

Differential Revision: https://reviews.llvm.org/D99249
2021-04-02 11:11:42 +03:00
Krasimir Georgiev c51e91e046 Revert "[Passes] Add relative lookup table converter pass"
This reverts commit 5178ffc7cf.

Compiling `llvm-profdata` with a compiler build from this produces a
crashing binary.
2021-03-30 14:13:37 +02:00
Gulfem Savrun Yeniceri 5178ffc7cf [Passes] Add relative lookup table converter pass
Lookup tables generate non PIC-friendly code, which requires dynamic relocation as described in:
https://bugs.llvm.org/show_bug.cgi?id=45244

This patch adds a new pass that converts lookup tables to relative lookup tables to make them PIC-friendly.

Differential Revision: https://reviews.llvm.org/D94355
2021-03-29 21:53:32 +00:00
Gulfem Savrun Yeniceri 5fbe1fdf17 Revert "[Passes] Add relative lookup table converter pass"
This reverts commit 5fd001a5ff
because it broke clang-with-thin-lto-ubuntu bot.
2021-03-24 18:59:33 +00:00
Gulfem Savrun Yeniceri 5fd001a5ff [Passes] Add relative lookup table converter pass
Lookup tables generate non PIC-friendly code, which requires dynamic relocation as described in:
https://bugs.llvm.org/show_bug.cgi?id=45244

This patch adds a new pass that converts lookup tables to relative lookup tables to make them PIC-friendly.

Differential Revision: https://reviews.llvm.org/D94355
2021-03-24 17:31:18 +00:00
Gulfem Savrun Yeniceri e3a6d70c68 Revert "[Passes] Add relative lookup table converter pass"
This reverts commit 78a65cd945 which
caused buildbot failures.
2021-03-23 00:43:16 +00:00
Gulfem Savrun Yeniceri 78a65cd945 [Passes] Add relative lookup table converter pass
Lookup tables generate non PIC-friendly code, which requires dynamic relocation as described in:
https://bugs.llvm.org/show_bug.cgi?id=45244

This patch adds a new pass that converts lookup tables to relative lookup tables to make them PIC-friendly.

Differential Revision: https://reviews.llvm.org/D94355
2021-03-22 22:09:02 +00:00
Nikita Popov 71a8e4e7d6 [MemCopyOpt] Enable MemorySSA by default
This enables use of MemorySSA instead of MemDep in MemCpyOpt. To
allow this without significant compile-time impact, the MemCpyOpt
pass is moved directly before DSE (in the cases where this was not
already the case), which allows us to reuse the existing MemorySSA
analysis.

Unlike the MemDep-based implementation, the MemorySSA-based MemCpyOpt
can also perform simple optimizations across basic blocks.

Differential Revision: https://reviews.llvm.org/D94376
2021-02-19 18:06:25 +01:00
Arthur Eubanks 6699029b67 [NewPM][opt] Run the "default" AA pipeline by default
We tend to assume that the AA pipeline is by default the default AA
pipeline and it's confusing when it's empty instead.

PR48779

Initially reverted due to BasicAA running analyses in an unspecified
order (multiple function calls as parameters), fixed by fetching
analyses before the call to construct BasicAA.

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D95117
2021-01-21 21:08:54 -08:00
Arthur Eubanks ba9b4ea4ee Revert "[NewPM][opt] Run the "default" AA pipeline by default"
This reverts commit be611431cd.

Other/new-pm-lto-defaults.ll failing
2021-01-21 20:16:34 -08:00
Arthur Eubanks be611431cd [NewPM][opt] Run the "default" AA pipeline by default
We tend to assume that the AA pipeline is by default the default AA
pipeline and it's confusing when it's empty instead.

PR48779

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D95117
2021-01-21 19:46:38 -08:00
Mircea Trofin e8049dc3c8 [NewPM][Inliner] Move the 'always inliner' case in the same CGSCC pass as 'regular' inliner
Expanding from D94808 - we ensure the same InlineAdvisor is used by both
InlinerPass instances. The notion of mandatory inlining is moved into
the core InlineAdvisor: advisors anyway have to handle that case, so
this change also factors out that a bit better.

Differential Revision: https://reviews.llvm.org/D94825
2021-01-15 17:59:38 -08:00
Arthur Eubanks 6c36286a2e [NewPM] Fix CGSCCOptimizerLateEPCallbacks place in pipeline
CGSCCOptimizerLateEPCallbacks are supposed to be run before the function
simplification pipeline, like in the legacy PM and as specified in the
comments for registerCGSCCOptimizerLateEPCallback().

Reviewed By: ychen

Differential Revision: https://reviews.llvm.org/D93871
2020-12-28 14:03:10 -08:00
Mircea Trofin 5fe10263ab [llvm][inliner] Reuse the inliner pass to implement 'always inliner'
Enable performing mandatory inlinings upfront, by reusing the same logic
as the full inliner, instead of the AlwaysInliner. This has the
following benefits:
- reduce code duplication - one inliner codebase
- open the opportunity to help the full inliner by performing additional
function passes after the mandatory inlinings, but before th full
inliner. Performing the mandatory inlinings first simplifies the problem
the full inliner needs to solve: less call sites, more contextualization, and,
depending on the additional function optimization passes run between the
2 inliners, higher accuracy of cost models / decision policies.

Note that this patch does not yet enable much in terms of post-always
inline function optimization.

Differential Revision: https://reviews.llvm.org/D91567
2020-11-30 12:03:39 -08:00
Roman Lebedev a8d74517dc
[PassManager] Run Induction Variable Simplification pass *after* Recognize loop idioms pass, not before
Currently, `-indvars` runs first, and then immediately after `-loop-idiom` does.
I'm not really sure if `-loop-idiom` requires `-indvars` to run beforehand,
but i'm *very* sure that `-indvars` requires `-loop-idiom` to run afterwards,
as it can be seen in the phase-ordering test.

LoopIdiom runs on two types of loops: countable ones, and uncountable ones.
For uncountable ones, IndVars obviously didn't make any change to them,
since they are uncountable, so for them the order should be irrelevant.
For countable ones, well, they should have been countable before IndVars
for IndVars to make any change to them, and since SCEV is used on them,
it shouldn't matter if IndVars have already canonicalized them.
So i don't really see why we'd want the current ordering.

Should this cause issues, it will give us a reproducer test case
that shows flaws in this logic, and we then could adjust accordingly.

While this is quite likely beneficial in-the-wild already,
it's a required part for the full motivational pattern
behind `left-shift-until-bittest` loop idiom (D91038).

Reviewed By: dmgreen

Differential Revision: https://reviews.llvm.org/D91800
2020-11-25 19:20:07 +03:00
Arthur Eubanks 2c7870dcca [NewPM] Add pipeline EP callback after initial frontend cleanup
This matches the legacy PM's EP_ModuleOptimizerEarly. Some backends use
this extension point and adding the pass somewhere else like
PipelineStartEPCallback doesn't work.

Reviewed By: ychen

Differential Revision: https://reviews.llvm.org/D91804
2020-11-24 21:14:36 -08:00
Arthur Eubanks 72badbcdcc [NPM] Move more O0 pass building into PassBuilder
This moves handling of alwaysinline, coroutines, matrix lowering, PGO,
and LTO-required passes into PassBuilder. Much of this is replicated
between Clang and opt. Other out-of-tree users also replicate some of
this, such as Rust [1] replicating the alwaysinline, LTO, and PGO
passes.

The LTO passes are also now run in
build(Thin)LTOPreLinkDefaultPipeline() since they are semantically
required for (Thin)LTO.

[1]: f5230fbf76/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp (L896)

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D91585
2020-11-19 11:22:23 -08:00
Florian Hahn 8dbe44cb29 Add pass to add !annotate metadata from @llvm.global.annotations.
This patch adds a new pass to add !annotation metadata for entries in
@llvm.global.anotations, which is generated  using
__attribute__((annotate("_name"))) on functions in Clang.

This has been discussed on llvm-dev as part of
    RFC: Combining Annotation Metadata and Remarks
    http://lists.llvm.org/pipermail/llvm-dev/2020-November/146393.html

Reviewed By: thegameg

Differential Revision: https://reviews.llvm.org/D91195
2020-11-16 14:57:11 +00:00
Florian Hahn 8bb6347939
Add !annotation metadata and remarks pass.
This patch adds a new !annotation metadata kind which can be used to
attach annotation strings to instructions.

It also adds a new pass that emits summary remarks per function with the
counts for each annotation kind.

The intended uses cases for this new metadata is annotating
'interesting' instructions and the remarks should provide additional
insight into transformations applied to a program.

To motivate this, consider these specific questions we would like to get answered:

* How many stores added for automatic variable initialization remain after optimizations? Where are they?
* How many runtime checks inserted by a frontend could be eliminated? Where are the ones that did not get eliminated?

Discussed on llvm-dev as part of 'RFC: Combining Annotation Metadata and Remarks'
(http://lists.llvm.org/pipermail/llvm-dev/2020-November/146393.html)

Reviewed By: thegameg, jdoerfert

Differential Revision: https://reviews.llvm.org/D91188
2020-11-13 13:24:10 +00:00
Fangrui Song 19dc6ec957 [test] Fix unused check prefixes in test/Linker/ and test/Other/ 2020-10-29 21:54:56 -07:00
Arthur Eubanks 0291e2c933 [Inliner] Run always-inliner in inliner-wrapper
An alwaysinline function may not get inlined in inliner-wrapper due to
the inlining order.

Previously for the following, the inliner would first inline @a() into @b(),

```
define void @a() {
entry:
  call void @b()
  ret void
}

define void @b() alwaysinline {
entry:
  br label %for.cond

for.cond:
  call void @a()
  br label %for.cond
}
```

making @b() recursive and unable to be inlined into @a(), ending at

```
define void @a() {
entry:
  call void @b()
  ret void
}

define void @b() alwaysinline {
entry:
  br label %for.cond

for.cond:
  call void @b()
  br label %for.cond
}
```

Running always-inliner first makes sure that we respect alwaysinline in more cases.

Fixes https://bugs.llvm.org/show_bug.cgi?id=46945.

Reviewed By: davidxl, rnk

Differential Revision: https://reviews.llvm.org/D86988
2020-10-22 19:16:25 -07:00
Florian Hahn 88241ffb56 [Passes] Move ADCE before DSE & LICM.
The adjustment seems to have very little impact on optimizations.
The only binary change with -O3 MultiSource/SPEC2000/SPEC2006 on X86 is
in consumer-typeset and the size there actually decreases by -0.1%, with
not significant changes in the stats.

On its own, it is mildly positive in terms of compile-time, most likely
due to LICM & DSE having to process slightly less instructions. It
should also be unlikely that DSE/LICM make much new code dead.

http://llvm-compile-time-tracker.com/compare.php?from=df63eedef64d715ce1f31843f7de9c11fe1e597f&to=e3bdfcf94a9eeae6e006d010464f0c1b3550577d&stat=instructions

With DSE & MemorySSA, it gives some nice compile-time improvements, due
to the fact that DSE can re-use the PDT from ADCE, if it does not make
any changes:

http://llvm-compile-time-tracker.com/compare.php?from=15fdd6cd7c24c745df1bb419e72ff66fd138aa7e&to=481f494515fc89cb7caea8d862e40f2c910dc994&stat=instructions

Reviewed By: xbolva00

Differential Revision: https://reviews.llvm.org/D87322
2020-10-21 10:30:56 +01:00
Hans Wennborg 0628bea513 Revert "[PM/CC1] Add -f[no-]split-cold-code CC1 option to toggle splitting"
This broke Chromium's PGO build, it seems because hot-cold-splitting got turned
on unintentionally. See comment on the code review for repro etc.

> This patch adds -f[no-]split-cold-code CC1 options to clang. This allows
> the splitting pass to be toggled on/off. The current method of passing
> `-mllvm -hot-cold-split=true` to clang isn't ideal as it may not compose
> correctly (say, with `-O0` or `-Oz`).
>
> To implement the -fsplit-cold-code option, an attribute is applied to
> functions to indicate that they may be considered for splitting. This
> removes some complexity from the old/new PM pipeline builders, and
> behaves as expected when LTO is enabled.
>
> Co-authored by: Saleem Abdulrasool <compnerd@compnerd.org>
> Differential Revision: https://reviews.llvm.org/D57265
> Reviewed By: Aditya Kumar, Vedant Kumar
> Reviewers: Teresa Johnson, Aditya Kumar, Fedor Sergeev, Philip Pfaffe, Vedant Kumar

This reverts commit 273c299d5d.
2020-10-19 12:31:14 +02:00
Florian Hahn 51ff04567b Recommit "[DSE] Switch to MemorySSA-backed DSE by default."
After investigation by @asbirlea, the issue that caused the
revert appears to be an issue in the original source, rather
than a problem with the compiler.

This patch enables MemorySSA DSE again.

This reverts commit 915310bf14.
2020-10-16 09:02:53 +01:00
Vedant Kumar 273c299d5d [PM/CC1] Add -f[no-]split-cold-code CC1 option to toggle splitting
This patch adds -f[no-]split-cold-code CC1 options to clang. This allows
the splitting pass to be toggled on/off. The current method of passing
`-mllvm -hot-cold-split=true` to clang isn't ideal as it may not compose
correctly (say, with `-O0` or `-Oz`).

To implement the -fsplit-cold-code option, an attribute is applied to
functions to indicate that they may be considered for splitting. This
removes some complexity from the old/new PM pipeline builders, and
behaves as expected when LTO is enabled.

Co-authored by: Saleem Abdulrasool <compnerd@compnerd.org>
Differential Revision: https://reviews.llvm.org/D57265
Reviewed By: Aditya Kumar, Vedant Kumar
Reviewers: Teresa Johnson, Aditya Kumar, Fedor Sergeev, Philip Pfaffe, Vedant Kumar
2020-10-15 23:13:33 +00:00
Yuanfang Chen 2c94d88e07 [NewPM] collapsing nested pass mangers of the same type
This is one of the reason for extra invalidations in D84959. In
practice, I don't think we have use cases needing this. This simplifies
the pipeline a bit and prune corner cases when considering
invalidations.

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D85676
2020-10-04 15:57:13 -07:00
Florian Hahn 915310bf14 Revert "[DSE] Switch to MemorySSA-backed DSE by default."
There appears to be a mis-compile with MemorySSA-backed DSE in
combination with llvm.lifetime.end. It currently appears like
DSE is doing the right thing and the llvm.lifetime.end markers
are incorrect. The reverted patch uncovers the mis-compile.

This patch temporarily switches back to the legacy DSE
implementation, while we investigate.

This reverts commit 9d172c8e9c.
2020-09-26 18:35:27 +01:00
Florian Hahn 9d172c8e9c Recommit "[DSE] Switch to MemorySSA-backed DSE by default."
This switches to using DSE + MemorySSA by default again, after
fixing the issues reported after the first commit.

Notable fixes fc82006331, a0017c2bc2.

This reverts commit 3a59628f3c.
2020-09-18 11:05:00 +01:00
Florian Hahn 3a59628f3c Revert "[DSE] Switch to MemorySSA-backed DSE by default."
This reverts commit fb109c42d9.

Temporarily revert due to a mis-compile pointed out at D87163.
2020-09-15 18:07:56 +01:00
Florian Hahn fb109c42d9 [DSE] Switch to MemorySSA-backed DSE by default.
The tests have been updated and I plan to move them from the MSSA
directory up.

Some end-to-end tests needed small adjustments. One difference to the
legacy DSE is that legacy DSE also deletes trivially dead instructions
that are unrelated to memory operations. Because MemorySSA-backed DSE
just walks the MemorySSA, we only visit/check memory instructions. But
removing unrelated dead instructions is not really DSE's job and other
passes will clean up.

One noteworthy change is in llvm/test/Transforms/Coroutines/ArgAddr.ll,
but I think this comes down to legacy DSE not handling instructions that
may throw correctly in that case. To cover this with MemorySSA-backed
DSE, we need an update to llvm.coro.begin to treat it's return value to
belong to the same underlying object as the passed pointer.

There are some minor cases MemorySSA-backed DSE currently misses, e.g. related
to atomic operations, but I think those can be implemented after the switch.

This has been discussed on llvm-dev:
http://lists.llvm.org/pipermail/llvm-dev/2020-August/144417.html

For the MultiSource/SPEC2000/SPEC2006 the number of eliminated stores
goes from ~17500 (legayc DSE) to ~26300 (MemorySSA-backed). More numbers
and details in the thread on llvm-dev.

Impact on CTMark:
```
                                     Legacy Pass Manager
                        exec instrs    size-text
O3                       + 0.60%        - 0.27%
ReleaseThinLTO           + 1.00%        - 0.42%
ReleaseLTO-g.            + 0.77%        - 0.33%
RelThinLTO (link only)   + 0.87%        - 0.42%
RelLO-g (link only)      + 0.78%        - 0.33%
```
http://llvm-compile-time-tracker.com/compare.php?from=3f22e96d95c71ded906c67067d75278efb0a2525&to=ae8be4642533ff03803967ee9d7017c0d73b0ee0&stat=instructions
```
                                     New Pass Manager
                       exec instrs.   size-text
O3                       + 0.95%       - 0.25%
ReleaseThinLTO           + 1.34%       - 0.41%
ReleaseLTO-g.            + 1.71%       - 0.35%
RelThinLTO (link only)   + 0.96%       - 0.41%
RelLO-g (link only)      + 2.21%       - 0.35%
```
http://195.201.131.214:8000/compare.php?from=3f22e96d95c71ded906c67067d75278efb0a2525&to=ae8be4642533ff03803967ee9d7017c0d73b0ee0&stat=instructions

Reviewed By: asbirlea, xbolva00, nikic

Differential Revision: https://reviews.llvm.org/D87163
2020-09-10 22:24:32 +01:00
Nikita Popov 25af353b0e [NewPM][LVI] Abandon LVI after CVP
As mentioned on D70376, LVI can currently cause performance issues
when running under NewPM. The problem is that, unlike the legacy
pass manager, NewPM will not immediately discard the LVI analysis
if the following pass does not need it. This is a problem, because
LVI has a high memory requirement, and mass invalidation of LVI
values is very inefficient. LVI should only be alive during passes
that actively interact with it.

This patch addresses the issue by explicitly abandoning LVI after CVP,
which gets us back to the LegacyPM behavior.

Differential Revision: https://reviews.llvm.org/D84959
2020-08-01 23:47:46 +02:00
Yuanfang Chen 555cf42f38 [NewPM][PassInstrument] Add PrintPass callback to StandardInstrumentations
Problem:
Right now, our "Running pass" is not accurate when passes are wrapped in adaptor because adaptor is never skipped and a pass could be skipped. The other problem is that "Running pass" for a adaptor is before any "Running pass" of passes/analyses it depends on. (for example, FunctionToLoopPassAdaptor). So the order of printing is not the actual order.

Solution:
Doing things like PassManager::Debuglogging is very intrusive because we need to specify Debuglogging whenever adaptor is created. (Actually, right now we're not specifying Debuglogging for some sub-PassManagers. Check PassBuilder)

This patch move debug logging for pass as a PassInstrument callback. We could be sure that all running passes are logged and in the correct order.

This could also be used to implement hierarchy pass logging in legacy PM. We could also move logging of pass manager to this if we want.

The test fixes looks messy. It includes changes:
- Remove PassInstrumentationAnalysis
- Remove PassAdaptor
- If a PassAdaptor is for a real pass, the pass is added
- Pass reorder (to the correct order), related to PassAdaptor
- Add missing passes (due to Debuglogging not passed down)

Reviewed By: asbirlea, aeubanks

Differential Revision: https://reviews.llvm.org/D84774
2020-07-30 10:07:57 -07:00
Sanjay Patel 57bb4787d7 [Pass Manager] remove EarlyCSE as clean-up for VectorCombine
EarlyCSE was added with D75145, but the motivating test is
not regressed by removing the extra pass now. That might be
because VectorCombine altered the way it processes instructions,
or it might be from (re)moving VectorCombine in the pipeline.

The extra round of EarlyCSE appears to cost approximately
0.26% in compile-time as discussed in D80236, so we need some
evidence to justify its inclusion here, but we do not have
that (yet).

I suspect that between SLP and VectorCombine, we are creating
patterns that InstCombine and/or codegen are not prepared for,
but we will need to reduce those examples and include them as
PhaseOrdering and/or test-suite benchmarks.
2020-05-24 12:36:21 -04:00
Sanjay Patel 6438ea45e0 [VectorCombine] position pass after SLP in the optimization pipeline rather than before
There are 2 known problem patterns shown in the test diffs here:
vector horizontal ops (an x86 specialization) and vector reductions.

SLP has greater ability to match and fold those than vector-combine,
so let SLP have first chance at that.

This is a quick fix while we continue to improve vector-combine and
possibly canonicalize to reduction intrinsics.

In the longer term, we should improve matching of these patterns
because if they were created in the "bad" forms shown here, then we
would miss optimizing them.

I'm not sure what is happening with alias analysis on the addsub test.
The old pass manager now shows an extra line for that, and we see an
improvement that comes from SLP vectorizing a store. I don't know
what's missing with the new pass manager to make that happen.
Strangely, I can't reproduce the behavior if I compile from C++ with
clang and invoke the new PM with "-fexperimental-new-pass-manager".

Differential Revision: https://reviews.llvm.org/D80236
2020-05-22 12:22:44 -04:00
Mircea Trofin d6695e1876 [llvm] Add interface to drive inlining decision using ML model
Summary:

This change introduces InliningAdvisor (and related APIs), the interface
that abstracts decision making away from the inlining pass. We will use
this interface to delegate decision making to a trained ML model,
subsequently (see referenced RFC).

RFC: http://lists.llvm.org/pipermail/llvm-dev/2020-April/140763.html

Reviewers: davidxl, eraman, dblaikie

Subscribers: mgorny, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D79042
2020-05-13 13:27:29 -07:00
Whitney Tsang 5c10c6e012 [PassBuilder] Moved ProfileSummaryAnalysis in buildInlinerPipeline.
Summary:
As commented in the code, ProfileSummaryAnalysis is required for inliner
pass to query, so this patch moved
RequireAnalysisPass<ProfileSummaryAnalysis> in the recently created
buildInlinerPipeline.
Reviewer: mtrofin, davidxl, tejohnson, dblaikie, jdoerfert, sstefan1
Reviewed By: mtrofin, davidxl, jdoerfert
Subscribers: hiraditya, steven_wu, dexonsmith, wuzish, llvm-commits,
jsji
Tag: LLVM
Differential Revision: https://reviews.llvm.org/D79696
2020-05-12 16:00:40 +00:00
Mircea Trofin c3770c5d6d [llvm][NFC] Factor out inlining pipeline as a module pipeline.
Summary:
This simplifies testing in scenarios where we want to set up module-wide
analyses for inlining. The patch enables treating inlining and its
function cleanups, as a module pass. The alternative would be for tests
to describe the pipeline, which is tedious and adds maintenance
overhead.

Reviewers: davidxl, dblaikie, jdoerfert, sstefan1

Subscribers: hiraditya, steven_wu, dexonsmith, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D78512
2020-04-24 09:24:12 -07:00
Masoud Ataei jaliseh 9ed0612cca Add InjectTLIMappings pass to new pass manager
This pass is created in d6de5f12d4 and tested
for new and legacy pass manager but never added to new pass manager pipeline.
I am adding it to new pass manager pipeline.

This pass is get used in Vector Function Database (VFDatabase) and without
this pass in new pass manager pipeline, none of the vector libraries are work
ing with new pass manager.

Related passes:
66c120f025
https://reviews.llvm.org/D74944

Differential revision: https://reviews.llvm.org/D75354
2020-04-06 13:16:48 -05:00
Tarindu Jayatilaka b43b59fcc0 Expose `attributor-disable` to the new and old pass managers
The new and old pass managers (PassManagerBuilder.cpp and
PassBuilder.cpp) are exposed to an `extern` declaration of
`attributor-disable` option which will guard the addition of the
attributor passes to the pass pipelines.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D76871
2020-04-05 22:29:34 -05:00
Sanjay Patel 71a316883d [PassManager] adjust VectorCombine placement
The initial placement of vector-combine in the opt pipeline revealed phase ordering bugs:
https://bugs.llvm.org/show_bug.cgi?id=45015
https://bugs.llvm.org/show_bug.cgi?id=42022

This patch contains a few independent changes:

1. Move the pass up in the pipeline, so it happens just after loop-vectorization.
   This is only to keep vectorization passes together in the pipeline at the moment.
   I don't have evidence of interaction between these yet.
2. Add an -early-cse pass after -vector-combine to clean up redundant ops. This was
   partly proposed as far back as rL219644 (which is why it's effectively being moved
   in the old PM code). This is important because the subsequent -instcombine doesn't
   work as well without EarlyCSE. With the CSE, -instcombine is able to squash
   shuffles together in 1 of the tests (because those are simple "select" shuffles).
3. Remove the -vector-combine pass that was running after SLP. We may want to do that
   eventually, but I don't have a test case to support it yet.

Differential Revision: https://reviews.llvm.org/D75145
2020-03-04 11:10:49 -05:00
Alina Sbirlea 4f33a68973 Compute ORE, BPI, BFI in Loop passes.
Summary:
Passes ORE, BPI, BFI are not being preserved by Loop passes, hence it
is incorrect to retrieve these passes as cached.
This patch makes the loop passes in question compute a new instance.

In some of these cases, however, it may be beneficial to change the Loop pass to
a Function pass instead, similar to the change for LoopUnrollAndJam.

Reviewers: chandlerc, dmgreen, jdoerfert, reames

Subscribers: mehdi_amini, hiraditya, zzheng, steven_wu, dexonsmith, Whitney, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72891
2020-02-12 09:15:18 -08:00
Sanjay Patel a17f03bd93 [VectorCombine] new IR transform pass for partial vector ops
We have several bug reports that could be characterized as "reducing scalarization",
and this topic was also raised on llvm-dev recently:
http://lists.llvm.org/pipermail/llvm-dev/2020-January/138157.html
...so I'm proposing that we deal with these patterns in a new, lightweight IR vector
pass that runs before/after other vectorization passes.

There are 4 alternate options that I can think of to deal with this kind of problem
(and we've seen various attempts at all of these), but they all have flaws:

    InstCombine - can't happen without TTI, but we don't want target-specific
                  folds there.
    SDAG - too late to assist other vectorization passes; TLI is not equipped
           for these kind of cost queries; limited to a single basic block.
    CGP - too late to assist other vectorization passes; would need to re-implement
          basic cleanups like CSE/instcombine.
    SLP - doesn't fit with existing transforms; limited to a single basic block.

This initial patch/transform is based on existing code in AggressiveInstCombine:
we walk backwards through the function looking for a pattern match. But we diverge
from that cost-independent IR canonicalization pass by using TTI to decide if the
vector alternative is profitable.

We probably have at least 10 similar bug reports/patterns (binops, constants,
inserts, cheap shuffles, etc) that would fit in this pass as follow-up enhancements.
It's possible that we could iterate on a worklist to fix-point like InstCombine does,
but it's safer to start with a most basic case and evolve from there, so I didn't
try to do anything fancy with this initial implementation.

Differential Revision: https://reviews.llvm.org/D73480
2020-02-09 10:04:41 -05:00