Commit Graph

659 Commits

Author SHA1 Message Date
Bjorn Pettersson 472462c472 [NewPM] Consistently use 'simplifycfg' rather than 'simplify-cfg'
There was an alias between 'simplifycfg' and 'simplify-cfg' in the
PassRegistry. That was the original reason for this patch, which
effectively removes the alias.

This patch also replaces all occurrances of 'simplify-cfg'
by 'simplifycfg'. Reason for choosing that form for the name is
that it matches the DEBUG_TYPE for the pass, and the legacy PM name
and also how it is spelled out in other passes such as
'loop-simplifycfg', and in other options such as
'simplifycfg-merge-cond-stores'.

I for some reason the name should be changed to 'simplify-cfg' in
the future, then I think such a renaming should be more widely done
and not only impacting the PassRegistry.

Reviewed By: aeubanks

Differential Revision: https://reviews.llvm.org/D105627
2021-07-09 09:47:03 +02:00
Bjorn Pettersson e24bb698bb [NewPM] Handle passes with params in -print-before/-print-after
To support options like -print-before=<pass> and -print-after=<pass>
the PassBuilder will register PassInstrumentation callbacks as well
as a mapping between internal pass class names and the pass names
used in those options (and other cmd line interfaces). But for
some reason all the passes that takes options where missing in those
maps, so for example "-print-after=loop-vectorize" didn't work.

This patch will add the missing entries by also taking care of
function and loop passes with params when setting up the class to
pass name maps.

One might notice that even with this patch it might be tricky to
know what pass name to use in options such as -print-after. This
because there only is a single mapping from class name to pass name,
while the PassRegistry currently is a bit messy as it sometimes
reuses the same class for different pass names (without using the
"pass with params" scheme, or the pass-name<variant> syntax).

It gets extra messy in some situations. For example the
MemorySanitizerPass can run like this (with debug and print-after)
  opt -passes='kmsan' -print-after=msan-module -debug-only=msan
The 'kmsan' alias for 'msan<kernel>' is just confusing as one might
think that 'kmsan' is a separate pass (but the DEBUG_TYPE is still
just 'msan'). And since the module pass version of the pass adds
a mapping from 'MemorySanitizerPass' to 'msan-module' one need to
use 'msan-module' in the print-before and print-after options.

Reviewed By: ychen

Differential Revision: https://reviews.llvm.org/D105006
2021-07-09 09:27:37 +02:00
Yuanfang Chen 0eb2b13d60 Add AddDiscriminatorsPass to NPM default O0 pipeline
AddDiscriminatorsPass is in Legacy PM's O0 pipeline. This patch did the same
for NPM O0 pipeline.

Reviewed By: aeubanks, MaskRay

Differential Revision: https://reviews.llvm.org/D105650
2021-07-08 16:37:20 -07:00
Roman Lebedev 333d3a3cdf
[NFC][PassBuilder] addVectorPasses(): clarify that 'IsLTO' is actually 'IsFullLTO'
I.e. it will be `false` for thin lto.
2021-07-01 10:09:24 +03:00
Xun Li 822b92aae4 [Coroutines] Add the newly generated SCCs back to the CGSCC work queue after CoroSplit actually happened
Relevant discussion can be found at: https://lists.llvm.org/pipermail/llvm-dev/2021-January/148197.html
In the existing design, An SCC that contains a coroutine will go through the folloing passes:
Inliner -> CoroSplitPass (fake) -> FunctionSimplificationPipeline -> Inliner -> CoroSplitPass (real) -> FunctionSimplificationPipeline

The first CoroSplitPass doesn't do anything other than putting the SCC back to the queue so that the entire pipeline can repeat.
As you can see, we run Inliner twice on the SCC consecutively without doing any real split, which is unnecessary and likely unintended.
What we really wanted is this:
Inliner -> FunctionSimplificationPipeline -> CoroSplitPass -> FunctionSimplificationPipeline
(note that we don't really need to run Inliner again on the ramp function after split).

Hence the way we do it here is to move CoroSplitPass to the end of the CGSCC pipeline, make it once for real, insert the newly generated SCCs (the clones) back to the pipeline so that they can be optimized, and also add a function simplification pipeline after CoroSplit to optimize the post-split ramp function.

This approach also conforms to how the new pass manager works instead of relying on an adhoc post split cleanup, making it ready for full switch to new pass manager eventually.

By looking at some of the changes to the tests, we can already observe that this changes allows for more optimizations applied to coroutines.

Reviewed By: aeubanks, ChuanqiXu

Differential Revision: https://reviews.llvm.org/D95807
2021-06-30 11:38:14 -07:00
Xun Li 31eb696fc4 [Coroutines] Remove CoroElide from O0 pipeline
CoroElide pass works only when a post-split coroutine is inlined into another post-split coroutine.
In O0, there is no inlining after CoroSplit, and hence no CoroElide can happen.
It's useless to put CoroElide pass in the O0 pipeline and it will never be triggered (unless I miss anything).

Differential Revision: https://reviews.llvm.org/D105066
2021-06-28 19:28:27 -07:00
Joseph Huber aaad46e6f5 [OpenMP] Run the OpenMPOpt module pass at O1
Now that the OpenMPOpt module pass include important optimizations for removing
globalization from offloading regions it should be run at a lower optimization
level.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D105056
2021-06-28 18:47:41 -04:00
Bjorn Pettersson d919b73564 [NewPM] Print passes with params when using "opt -print-passes"
Make sure we also print passes with params when using "opt -print-passes".

Differential Revision: https://reviews.llvm.org/D104625
2021-06-22 09:01:38 +02:00
Roman Lebedev e52364532a
[NewPM] Remove SpeculateAroundPHIs pass
Addition of this pass has been botched.
There is no particular reason why it had to be sold as an inseparable part
of new-pm transition. It was added when old-pm was still the default,
and very *very* few users were actually tracking new-pm,
so it's effects weren't measured.

Which means, some of the turnoil of the new-pm transition
are actually likely regressions due to this pass.

Likewise, there has been a number of post-commit feedback
(post new-pm switch), namely
* https://reviews.llvm.org/D37467#2787157 (regresses HW-loops)
* https://reviews.llvm.org/D37467#2787259 (should not be in middle-end, should run after LSR, not before)
* https://reviews.llvm.org/D95789 (an attempt to fix bad loop backedge metadata)
and in the half year past, the pass authors (google) still haven't found time to respond to any of that.

Hereby it is proposed to backout the pass from the pipeline,
until someone who cares about it can address the issues reported,
and properly start the process of adding a new pass into the pipeline,
with proper performance evaluation.

Furthermore, neither google nor facebook reports any perf changes
from this change, so i'm dropping the pass completely.
It can always be re-reverted should/if anyone want to pick it up again.

Reviewed By: aeubanks

Differential Revision: https://reviews.llvm.org/D104099
2021-06-15 20:35:55 +03:00
Sjoerd Meijer c4a0969b9c Function Specialization Pass
This adds a function specialization pass to LLVM. Constant parameters
like function pointers and constant globals are propagated to the callee by
specializing the function.

This is a first version with a number of limitations:
- The pass is off by default, so needs to be enabled on the command line,
- It does not handle specialization of recursive functions,
- It does not yet handle constants and constant ranges,
- Only 1 argument per function is specialised,
- The cost-model could be further looked into, and perhaps related,
- We are not yet caching analysis results.

This is based on earlier work by Matthew Simpson (D36432) and Vinay Madhusudan.
More recently this was also discussed on the list, see:

https://lists.llvm.org/pipermail/llvm-dev/2021-March/149380.html.

The motivation for this work is that function specialisation often comes up as
a reason for performance differences of generated code between LLVM and GCC,
which has this enabled by default from optimisation level -O3 and up. And while
this certainly helps a few cpu benchmark cases, this also triggers in real
world codes and is thus a generally useful transformation to have in LLVM.

Function specialisation has great potential to increase compile-times and
code-size.  The summary from some investigations with this patch is:
- Compile-time increases for short compile jobs is high relatively, but the
  increase in absolute numbers still low.
- For longer compile-jobs, the extra compile time is around 1%, and very much
  in line with GCC.
- It is difficult to blame one thing for compile-time increases: it looks like
  everywhere a little bit more time is spent processing more functions and
  instructions.
- But the function specialisation pass itself is not very expensive; it doesn't
  show up very high in the profile of the optimisation passes.

The goal of this work is to reach parity with GCC which means that eventually
we would like to get this enabled by default. But first we would like to address
some of the limitations before that.

Differential Revision: https://reviews.llvm.org/D93838
2021-06-11 09:11:29 +01:00
maekawatoshiki 09e92c607c [LoopUnrollAndJam] Change LoopUnrollAndJamPass to LoopNest pass
This patch changes LoopUnrollAndJamPass from FunctionPass to LoopNest pass.
The next patch will utilize LoopNest to effectively handle loop nests.

Also, a crash problem on legacy pass manager is fixed.

Reviewed By: Whitney

Differential Revision: https://reviews.llvm.org/D99149
2021-06-08 20:30:02 +09:00
Jingu Kang a2a0ac42ab [SimpleLoopBoundSplit] Split Bound of Loop which has conditional branch with IV
This pass transforms loops that contain a conditional branch with induction
variable. For example, it transforms left code to right code:

                             newbound = min(n, c)
 while (iv < n) {            while(iv < newbound) {
   A                           A
   if (iv < c)                 B
     B                         C
   C                         }
 }                           if (iv != n) {
                               while (iv < n) {
                                 A
                                 C
                               }
                             }

Differential Revision: https://reviews.llvm.org/D102234
2021-06-07 10:55:25 +01:00
maekawatoshiki 0a9d079931 Revert "[LoopUnrollAndJam] Change LoopUnrollAndJamPass to LoopNest pass"
This reverts commit 2165360003.

To fix the crash problem in legacy pass manager
2021-06-07 01:26:47 +09:00
Sanjay Patel 403cfe5d70 [PassManager] unify late simplifycfg options between regular and LTO pipelines
This is split off from D102002, and I think it is clear that
the difference in behavior was not intended. Options were
added to SimplifyCFG over time, but different chunks of
the pass pipelines were not kept in sync.
2021-05-28 13:06:49 -04:00
eopXD fa488ea864 [LoopNest][LoopFlatten] Change LoopFlattenPass to LoopNest pass
This patch changes LoopFlattenPass from FunctionPass to LoopNestPass.

Utilize LoopNest and let function 'Flatten' generate information from it.

Reviewed By: Whitney

Differential Revision: https://reviews.llvm.org/D102904
2021-05-28 15:43:12 +00:00
eopXD e96d6f4821 Revert "[LoopNest][LoopFlatten] Change LoopFlattenPass to LoopNest pass"
This reverts commit 7952ddb21f.

Differential Revision: https://reviews.llvm.org/D103302
2021-05-28 07:58:06 +00:00
eopXD 7e06cf8f1b Revert "[LoopNest][LoopFlatten] Change LoopFlattenPass to LoopNest pass"
This reverts commit ffc4d3e068.
2021-05-28 07:48:04 +00:00
eopXD ffc4d3e068 [LoopNest][LoopFlatten] Change LoopFlattenPass to LoopNest pass
This patch changes LoopFlattenPass from FunctionPass to LoopNestPass.

Utilize LoopNest and let function 'Flatten' generate information from it.

Reviewed By: Whitney

Differential Revision: https://reviews.llvm.org/D102904
2021-05-28 07:25:53 +00:00
eopXD 7952ddb21f [LoopNest][LoopFlatten] Change LoopFlattenPass to LoopNest pass
This patch changes LoopFlattenPass from FunctionPass to LoopNestPass.

Utilize LoopNest and let function 'Flatten' generate information from it.

Reviewed By: Whitney

Differential Revision: https://reviews.llvm.org/D102904
2021-05-28 07:11:26 +00:00
maekawatoshiki 2165360003 [LoopUnrollAndJam] Change LoopUnrollAndJamPass to LoopNest pass
This patch changes LoopUnrollAndJamPass from FunctionPass to LoopNest pass.
The next patch will utilize LoopNest to effectively handle loop nests.

Reviewed By: Whitney

Differential Revision: https://reviews.llvm.org/D99149
2021-05-28 01:17:23 +09:00
maekawatoshiki e77d24f70a Revert "[LoopUnrollAndJam] Change LoopUnrollAndJamPass to LoopNest pass"
This reverts commit d65c32fb41.
2021-05-25 11:39:49 +09:00
maekawatoshiki d65c32fb41 [LoopUnrollAndJam] Change LoopUnrollAndJamPass to LoopNest pass
This patch changes LoopUnrollAndJamPass from FunctionPass to LoopNest pass.
The next patch will utilize LoopNest to effectively handle loop nests.

Reviewed By: Whitney

Differential Revision: https://reviews.llvm.org/D99149
2021-05-23 22:32:01 +09:00
Arthur Eubanks a52530dd6a Revert "[NPM] Do not run function simplification pipeline unnecessarily"
This reverts commit 97ab068034.

Depends on D100917, which is to be reverted.
2021-05-21 16:38:02 -07:00
maekawatoshiki fd53cb4148 Revert "[LoopUnrollAndJam] Change LoopUnrollAndJamPass to LoopNest pass"
This reverts commit cea7a3fe3d.
To investigate sanitizer-x86_64-linux-fast failure.
2021-05-22 01:40:43 +09:00
maekawatoshiki cea7a3fe3d [LoopUnrollAndJam] Change LoopUnrollAndJamPass to LoopNest pass
This patch changes LoopUnrollAndJamPass from FunctionPass to LoopNest pass.
The next patch will utilize LoopNest to effectively handle loop nests.

Reviewed By: Whitney

Differential Revision: https://reviews.llvm.org/D99149
2021-05-21 23:57:39 +09:00
Florian Hahn 860b37526a [Passes] Run GlobalsAA before LICM during LTO in new PM.
This patch adjusts the LTO pipeline in the new PM to run GlobalsAA
before LICM to match the legacy PM.

This fixes a regression where the new PM failed to vectorize loops that
require hoisting/sinking by LICM depending on GlobalsAA info.

Reviewed By: aeubanks

Differential Revision: https://reviews.llvm.org/D102345
2021-05-13 13:11:18 +01:00
Florian Hahn 3eaf235855 [Passes] Use MemorySSA for LICM during LTO.
Split off from D102345 to commit this separately from other changes in
the patch. This aligns the behavior of the new PM with the legacy PM
for LTO, with respect to running LICM.

Together with the remaining changes in D102345, this fixes new PM
regressions where we fail to vectorize loops that are vectorized with
the legacy PM.
2021-05-13 12:16:41 +01:00
Sanjay Patel 88d8f10baf [PassManager] add helper function to hold set of vector passes (2nd try)
This is better no-functional-change-intended than the 1st attempt.
As noted in D102002, there were at least 2 diffs that went
unchecked in pass manager regressions tests: different pass
parameters (SimplifyCFG) and an extension point/callback.
Those should be lifted from the original code blocks correctly
now.
2021-05-10 14:43:00 -04:00
Sanjay Patel 822be4bec8 Revert "[PassManager] add helper function to hold set of vector passes"
This reverts commit fefcb1f878.
It was supposed to be NFC, but as noted in the post-commit
comments in D102002, that was not true: SimplifyCFG uses
different parameters and there's a difference in an
extension point / callback.
2021-05-10 10:59:30 -04:00
Arthur Eubanks 34a8a437bf [NewPM] Hide pass manager debug logging behind -debug-pass-manager-verbose
Printing pass manager invocations is fairly verbose and not super
useful.

This allows us to remove DebugLogging from pass managers and PassBuilder
since all logging (aside from analysis managers) goes through
instrumentation now.

This has the downside of never being able to print the top level pass
manager via instrumentation, but that seems like a minor downside.

Reviewed By: ychen

Differential Revision: https://reviews.llvm.org/D101797
2021-05-07 21:51:47 -07:00
Fangrui Song d8aba75a76 Internalize some cl::opt global variables or move them under namespace llvm 2021-05-07 11:15:43 -07:00
Sanjay Patel fefcb1f878 [PassManager] add helper function to hold set of vector passes
This is no-functional-change-intended (NFC) and split off from
D102002 (which proposes to eliminate the LTO-based differences).
2021-05-06 15:36:15 -04:00
Mircea Trofin 97ab068034 [NPM] Do not run function simplification pipeline unnecessarily
The CGSCC pass manager interplay with the FunctionAnalysisManagerCGSCCProxy is 'special' in the sense that the former will rerun the latter if there are changes to a SCC structure; that being said, some of the functions in the SCC may be unchanged. In that case, the function simplification pipeline will be re-run, which impacts compile time[1].

This patch allows the function simplification pipeline be skipped if it was already run and the function was not modified since.

The behavior is currently disabled by default. This is because, currently, the rerunning of the function simplification pipeline on an unchanged function may still result in changes. The patch simplifies investigating and fixing those cases where repeated function pass runs do actually positively impact code quality, while offering an easy workaround for those impacted negatively by compile time regressions, and not impacting mainline scenarios.

[1] A [[ http://llvm-compile-time-tracker.com/compare.php?from=eb37d3546cd0c6e67798496634c45e501f7806f1&to=ac722d1190dc7bbdd17e977ef7ec95e69eefc91e&stat=instructions | compile time tracker ]] run with the option enabled.

Differential Revision: https://reviews.llvm.org/D98103
2021-05-06 12:24:33 -07:00
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
Florian Hahn ed9df5bd2f
[Passes] Run sinking/hoisting in SimplifyCFG earlier.
Hoisting and sinking instructions out of conditional blocks enables
additional vectorization by:

1. Executing memory accesses unconditionally.
2. Reducing the number of instructions that need predication.

After disabling early hoisting / sinking, we miss out on a few
vectorization opportunities. One of those is causing a ~10% performance
regression in one of the Geekbench benchmarks on AArch64.

This patch tires to recover the regression by running hoisting/sinking
as part of a SimplifyCFG run after LoopRotate and before LoopVectorize.

Note that in the legacy pass-manager, we run LoopRotate just before
vectorization again and there's no SimplifyCFG run in between, so the
sinking/hoisting may impact the later run on LoopRotate. But the impact
should be limited and the benefit of hosting/sinking at this stage
should outweigh the risk of not rotating.

Compile-time impact looks slightly positive for most cases.
http://llvm-compile-time-tracker.com/compare.php?from=2ea7fb7b1c045a7d60fcccf3df3ebb26aa3699e5&to=e58b4a763c691da651f25996aad619cb3d946faf&stat=instructions

NewPM-O3: geomean -0.19%
NewPM-ReleaseThinLTO: geoman -0.54%
NewPM-ReleaseLTO-g: geomean -0.03%

With a few benchmarks seeing a notable increase, but also some
improvements.

Alternative to D101290.

Reviewed By: lebedev.ri

Differential Revision: https://reviews.llvm.org/D101468
2021-04-30 12:23:57 +01:00
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
Jingu Kang 798b0fd36b [NPM] Fix typo inisLTOPreLink for loop rotate
Differential Revision: https://reviews.llvm.org/D100033
2021-04-07 15:08:37 +01:00
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
Jamie Schmeiser 64336d3421 Revert "A new option -print-on-crash that prints the IR as it was upon entering the last pass when there is a crash."
This reverts commit 9544a32287.
2021-03-23 10:09:27 -04:00
Jamie Schmeiser 9544a32287 A new option -print-on-crash that prints the IR as it was upon entering the last pass when there is a crash.
Summary:
The IR is saved in its print form before each pass is started and a
signal handler is registered.  If the compilation crashes, the signal
handler will print the saved IR to dbgs().  This option
can be modified using -print-module-scope to get the IR for the complete
module.  Note that this option only works with the new pass manager.

Author: Jamie Schmeiser <schmeise@ca.ibm.com>
Reviewed By: aeubanks (Arthur Eubanks) yrouban (Yevgeny Rouban)
Differential Revision: https://reviews.llvm.org/D86657
2021-03-23 09:29:17 -04:00
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
Sriraman Tallam 0ba1ebcbb7 Remove original implementation of UniqueInternalLinkageNames pass.
D96109 was recently submitted which contains the refactored implementation of
-funique-internal-linakge-names by adding the unique suffixes in clang rather
than as an LLVM pass. Deleting the former implementation in this change.

Differential Revision: https://reviews.llvm.org/D98234
2021-03-10 11:57:40 -08:00
Ta-Wei Tu 8a003861a3 [NPM] Add -enable-loopinterchange option to NPM
We have the `enable-loopinterchange` option in legacy pass manager but not in NPM.
Add `LoopInterchange` pass to the optimization pipeline (at the same position as before)
when `enable-loopinterchange` is turned on.

Reviewed By: aeubanks, fhahn

Differential Revision: https://reviews.llvm.org/D98116
2021-03-07 02:39:28 +08:00
Arthur Eubanks a9b33ffb8f [ThinLTO][NewPM] Clean up dead code under -O0
We're running into undefined references using ThinLTO with -O0 on
Windows/Chrome. This fixes that.

This matches the legacy PM.

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D97414
2021-02-24 17:08:57 -08:00
Vitaly Buka 8560c2d426 [ThinLTO, NewPM] Run OptimizerLastEPCallbacks from buildThinLTOPreLinkDefaultPipeline
-O1 and above do dont call real optimizer pipeline in ThinLTO PreLink.
Also clang can't add PostLink OptimizerLastEPCallbacks for in-process ThinLTO.
This results in missing sanitizer passes with ThinLTO.

Simple working solution is just call OptimizerLastEPCallbacks
at the end of buildThinLTOPreLinkDefaultPipeline.

Differential Revision: https://reviews.llvm.org/D96320
2021-02-23 22:14:41 -08:00
Wenlei He a952d7291e [SampleFDO] Skip PreLink ICP for better profile quality of MonoLTO PostLink
For ThinLTO, PreLink ICP is skipped to favor better profile annotation during LTO PostLink. This change applies the same tweak for MonoLTO. Note that PreLink ICP not only makes PostLink profile annotation harder, it is also uncoordinated with PostLink ICP so duplicated ICP could happen.

Differential Revision: https://reviews.llvm.org/D97028
2021-02-19 19:35:23 -08:00
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
David Green c141c6551b [NPM][LTO] Do not enable MemorySSA with LoopFullUnrollPass
As with the standard opt pipeline, we disable the MemorySSA dependency
in the LTO LPM pipeline as not all passes preserve MemorySSA.
2021-02-19 08:35:11 +00:00
David Green 908ac47ef4 [NPM][LTO] Update buildLTODefaultPipeline to be more in-line with the old pass manager
The NPM LTO pipeline has a lot of fixme's and missing passes, causing a
lot of regressions after the switch in c70737b. Notably unrolling and
vectorization were both disabled, but many other passes are missing
compared to the old pass manager. This attempt to enable the most
obvious missing passes like the unroller, vectorization and other loop
passes, fixing the existing FIXME comments.

Differential Revision: https://reviews.llvm.org/D96780
2021-02-17 16:56:28 +00:00
Sanne Wouda 93d9a4c95a Use LoopRotate PrepareForLTO stage in NPM
The PrepareForLTO stage of LoopRotate tries to avoid unrolling loops
with calls that might be inlined later.  See D94232 where this was
introduced.

We didn't catch all occurances of the LoopRotatePass in the New Pass
Manager, so the original regression in astar returned with the pass
manager switch.
2021-02-17 14:06:57 +00:00
Sameer Sahasrabuddhe 11bf7da64a [NewPM] Introduce (GPU)DivergenceAnalysis in the new pass manager
The GPUDivergenceAnalysis is now renamed to just "DivergenceAnalysis"
since there is no conflict with LegacyDivergenceAnalysis. In the
legacy PM, this analysis can only be used through the legacy DA
serving as a wrapper. It is now made available as a pass in the new
PM, and has no relation with the legacy DA.

The new DA currently cannot handle irreducible control flow; its
presence can cause the analysis to run indefinitely. The analysis is
now modified to detect this and report all instructions in the
function as divergent. This is super conservative, but allows the
analysis to be used without hanging the compiler.

Reviewed By: aeubanks

Differential Revision: https://reviews.llvm.org/D96615
2021-02-16 10:26:45 +05:30
Arthur Eubanks 5d960cba34 [opt][NewPM] Add a --print-passes flag to print all available passes
It seems nicer to list passes given a flag rather than displaying all
passes in opt --help.

This is awkwardly structured because a PassBuilder is required, but
reusing the PassBuilder in runPassPipeline() doesn't work because we
read the input IR before getting to runPassPipeline(). So printing the
list of passes needs to happen before reading the input IR. If we remove
the legacy PM code in main() and move everything from NewPMDriver.cpp
into opt.cpp, we can create the PassBuilder before reading IR and check
if we should print the list of passes and exit. But until then this hack
seems fine.

Compared to the legacy PM, the new PM passes are lacking descriptions.
We'll need to figure out a way to add descriptions if we think this is
important.

Also, this only works for passes specified in PassRegistry.def. If we
want to print other custom registered passes, we'll need a different
mechanism.

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D96101
2021-02-10 11:22:12 -08:00
Arthur Eubanks f020544601 [NewPM][HelloWorld] Move HelloWorld to Utils
To prevent creating a new component, which creates a new library.

Reviewed By: ychen

Differential Revision: https://reviews.llvm.org/D95907
2021-02-03 12:59:40 -08:00
Hongtao Yu 3d89b3cbec [CSSPGO] Introducing distribution factor for pseudo probe.
Sample re-annotation is required in LTO time to achieve a reasonable post-inline profile quality. However, we have seen that such LTO-time re-annotation degrades profile quality. This is mainly caused by preLTO code duplication that is done by passes such as loop unrolling, jump threading, indirect call promotion etc, where samples corresponding to a source location are aggregated multiple times due to the duplicates. In this change we are introducing a concept of distribution factor for pseudo probes so that samples can be distributed for duplicated probes scaled by a factor. We hope that optimizations duplicating code well-maintain the branch frequency information (BFI) based on which probe distribution factors are calculated. Distribution factors are updated at the end of preLTO pipeline to reflect an estimated portion of the real execution count.

This change also introduces a pseudo probe verifier that can be run after each IR passes to detect duplicated pseudo probes.

A saturated distribution factor stands for 1.0. A pesudo probe will carry a factor with the value ranged from 0.0 to 1.0. A 64-bit integral distribution factor field that represents [0.0, 1.0] is associated to each block probe. Unfortunately this cannot be done for callsite probes due to the size limitation of a 32-bit Dwarf discriminator. A 7-bit distribution factor is used instead.

Changes are also needed to the sample profile inliner to deal with prorated callsite counts. Call sites duplicated by PreLTO passes, when later on inlined in LTO time, should have the callees’s probe prorated based on the Prelink-computed distribution factors. The distribution factors should also be taken into account when computing hotness for inline candidates. Also, Indirect call promotion results in multiple callisites. The original samples should be distributed across them. This is fixed by adjusting the callisites' distribution factors.

Reviewed By: wmi

Differential Revision: https://reviews.llvm.org/D93264
2021-02-02 11:55:01 -08:00
Arthur Eubanks 7739f9ff97 [NewPM][Unswitch] Add option to disable -O3 non-trivial unswitching
Some benchmarks regress with non-trivial unswitching, so add an option
to opt-out of performing non-trivial unswitching while investigating.

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D95796
2021-02-01 11:11:59 -08:00
Bjorn Pettersson a9bd3d37bd [NewPM] Add ExtraVectorizerPasses support
As it looks like NewPM generally is using SimpleLoopUnswitch
instead of LoopUnswitch, this patch also use SimpleLoopUnswitch
in the ExtraVectorizerPasses sequence (compared with LegacyPM
which use the LoopUnswitch pass).

Reviewed By: aeubanks

Differential Revision: https://reviews.llvm.org/D95457
2021-01-26 22:59:10 +01:00
Florian Hahn 83daa49758
[LoopRotate] Add PrepareForLTO stage, avoid rotating with inline cands.
D84108 exposed a bad interaction between inlining and loop-rotation
during regular LTO, which is causing notable regressions in at least
CINT2006/473.astar.

The problem boils down to: we now rotate a loop just before the vectorizer
which requires duplicating a function call in the preheader when compiling
the individual files ('prepare for LTO'). But this then prevents further
inlining of the function during LTO.

This patch tries to resolve this issue by making LoopRotate more
conservative with respect to rotating loops that have inline-able calls
during the 'prepare for LTO' stage.

I think this change intuitively improves the current situation in
general. Loop-rotate tries hard to avoid creating headers that are 'too
big'. At the moment, it assumes all inlining already happened and the
cost of duplicating a call is equal to just doing the call. But with LTO,
inlining also happens during full LTO and it is possible that a previously
duplicated call is actually a huge function which gets inlined
during LTO.

From the perspective of LV, not much should change overall. Most loops
calling user-provided functions won't get vectorized to start with
(unless we can infer that the function does not touch memory, has no
other side effects). If we do not inline the 'inline-able' call during
the LTO stage, we merely delayed loop-rotation & vectorization. If we
inline during LTO, chances should be very high that the inlined code is
itself vectorizable or the user call was not vectorizable to start with.

There could of course be scenarios where we inline a sufficiently large
function with code not profitable to vectorize, which would have be
vectorized earlier (by scalarzing the call). But even in that case,
there probably is no big performance impact, because it should be mostly
down to the cost-model to reject vectorization in that case. And then
the version with scalarized calls should also not be beneficial. In a way,
LV should have strictly more information after inlining and make more
accurate decisions (barring cost-model issues).

There is of course plenty of room for things to go wrong unexpectedly,
so we need to keep a close look at actual performance and address any
follow-up issues.

I took a look at the impact on statistics for
MultiSource/SPEC2000/SPEC2006. There are a few benchmarks with fewer
loops rotated, but no change to the number of loops vectorized.

Reviewed By: sanwou01

Differential Revision: https://reviews.llvm.org/D94232
2021-01-19 10:15:29 +00:00
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 a03ffa9850 [NewPM] Fix placement of LoopFlatten
https://reviews.llvm.org/D90402 was inconsistent with where it put
LoopFlatten between the two pass managers. It also missed adding it to
the non-O1 function simplification pipeline.

PR48738

Reviewed By: SjoerdMeijer

Differential Revision: https://reviews.llvm.org/D94650
2021-01-14 09:49:31 -08:00
Wei Mi 86341247c4 [NFC] Rename ThinLTOPhase to ThinOrFullLTOPhase and move it from PassBuilder.h
to Pass.h.

In some compiler passes like SampleProfileLoaderPass, we want to know which
LTO/ThinLTO phase the pass is in. Currently the phase is represented in enum
class PassBuilder::ThinLTOPhase, so it is only available in PassBuilder and
it also cannot represent phase in full LTO. The patch extends it to include
full LTO phases and move it from PassBuilder.h to Pass.h, then it is much
easier for PassBuilder to communiate with each pass about current LTO phase.

Differential Revision: https://reviews.llvm.org/D94613
2021-01-13 15:55:40 -08:00
Arthur Eubanks 39e6d24237 [NewPM] Only non-trivially loop unswitch at -O3 and for non-optsize functions
This matches the legacy pipeline/pass.

Reviewed By: asbirlea, SjoerdMeijer

Differential Revision: https://reviews.llvm.org/D94559
2021-01-13 14:54:49 -08:00
Arthur Eubanks f748e92295 [NewPM] Run non-trivial loop unswitching under -O2/3/s/z
Fixes https://bugs.llvm.org/show_bug.cgi?id=48715.

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D94448
2021-01-12 11:04:40 -08:00
Arthur Eubanks 69cf735062 [NewPM] Don't error when there's an unrecognized pass name
This currently blocks --print-before/after with a legacy PM pass, for
example when we use the new PM for the optimization pipeline but the
legacy PM for the codegen pipeline. Also in the future when the codegen
pipeline works with the new PM there will be multiple places to specify
passes, so even when everything is using the new PM, there will still be
multiple places that can accept different pass names.

Reviewed By: hoy, ychen

Differential Revision: https://reviews.llvm.org/D94283
2021-01-07 22:33:32 -08:00
Arthur Eubanks 28a326eba0 [NFC] Rename registerAliasAnalyses -> registerDefaultAliasAnalyses
To clarify that this only affects the "default" AA.

Reviewed By: ychen

Differential Revision: https://reviews.llvm.org/D93980
2021-01-05 11:07:58 -08:00
Kazu Hirata eb198f4c3c [llvm] Use llvm::any_of (NFC) 2021-01-04 11:42:47 -08:00
Florian Hahn c367258b5c
[SimplifyCFG] Enabled hoisting late in LTO pipeline.
bb7d3af113 disabled hoisting in SimplifyCFG by default, but enabled it
late in the pipeline. But it appears as if the LTO pipelines got missed.

This patch adjusts the LTO pipelines to also enable hoisting in the
later stages.

Unfortunately there's no easy way to add a test for the change I think.

Reviewed By: lebedev.ri

Differential Revision: https://reviews.llvm.org/D93684
2021-01-04 16:26:58 +00:00
Hongtao Yu 01f0d162d6 Moving UniqueInternalLinkageNamesPass to the start of IR pipelines.
`UniqueInternalLinkageNamesPass` is useful to CSSPGO, especially when pseudo probe is used. It solves naming conflict for static functions which otherwise will share a merged profile and likely have a profile quality issue with mismatched CFG checksums. Since the pseudo probe instrumentation happens very early in the pipeline, I'm moving `UniqueInternalLinkageNamesPass` right before it. This is being done only to the new pass manager.

Reviewed By: dblaikie, aeubanks

Differential Revision: https://reviews.llvm.org/D93656
2021-01-02 14:26:21 -08:00
Arthur Eubanks c2ef06d3dd [NewPM] Port infer-address-spaces
And add it to the AMDGPU opt pipeline.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D93880
2020-12-28 19:58:12 -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
Arthur Eubanks 76f4f42eba [NewPM] Add TargetMachine method to add alias analyses
AMDGPUTargetMachine::adjustPassManager() adds some alias analyses to the
legacy PM. We need a way to do the same for the new PM in order to port
AMDGPUTargetMachine::adjustPassManager() to the new PM.

Currently the new PM adds alias analyses by creating an AAManager via
PassBuilder and overriding the AAManager a PassManager uses via
FunctionAnalysisManager::registerPass().

We will continue to respect a custom AA pipeline that specifies an exact
AA pipeline to use, but for "default" we will now add alias analyses
that backends specify. Most uses of PassManager use the "default"
AAManager created by PassBuilder::buildDefaultAAPipeline(). Backends can
override the newly added TargetMachine::registerAliasAnalyses() to add custom
alias analyses.

Reviewed By: ychen

Differential Revision: https://reviews.llvm.org/D93261
2020-12-21 13:46:07 -08:00
Andrew Litteken dae34463e3 [IRSim][IROutliner] Adding the extraction basics for the IROutliner.
Extracting the similar regions is the first step in the IROutliner.

Using the IRSimilarityIdentifier, we collect the SimilarityGroups and
sort them by how many instructions will be removed.  Each
IRSimilarityCandidate is used to define an OutlinableRegion.  Each
region is ordered by their occurrence in the Module and the regions that
are not compatible with previously outlined regions are discarded.

Each region is then extracted with the CodeExtractor into its own
function.

We test that correctly extract in:
test/Transforms/IROutliner/extraction.ll
test/Transforms/IROutliner/address-taken.ll
test/Transforms/IROutliner/outlining-same-globals.ll
test/Transforms/IROutliner/outlining-same-constants.ll
test/Transforms/IROutliner/outlining-different-structure.ll

Recommit of bf899e8913 fixing memory
leaks.

Reviewers: paquette, jroelofs, yroux

Differential Revision: https://reviews.llvm.org/D86975
2020-12-17 11:27:26 -06:00
dfukalov 9ed8e0caab [NFC] Reduce include files dependency and AA header cleanup (part 2).
Continuing work started in https://reviews.llvm.org/D92489:

Removed a bunch of includes from "AliasAnalysis.h" and "LoopPassManager.h".

Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D92852
2020-12-17 14:04:48 +03:00
Bardia Mahjour 6eff12788e [DDG] Data Dependence Graph - DOT printer - recommit
This is being recommitted to try and address the MSVC complaint.

This patch implements a DDG printer pass that generates a graph in
the DOT description language, providing a more visually appealing
representation of the DDG. Similar to the CFG DOT printer, this
functionality is provided under an option called -dot-ddg and can
be generated in a less verbose mode under -dot-ddg-only option.

Reviewed By: Meinersbur

Differential Revision: https://reviews.llvm.org/D90159
2020-12-16 12:37:36 -05:00
Bardia Mahjour a29ecca781 Revert "[DDG] Data Dependence Graph - DOT printer"
This reverts commit fd4a10732c, to
investigate the failure on windows: http://lab.llvm.org:8011/#/builders/127/builds/3274
2020-12-14 16:54:20 -05:00
Bardia Mahjour fd4a10732c [DDG] Data Dependence Graph - DOT printer
This patch implements a DDG printer pass that generates a graph in
the DOT description language, providing a more visually appealing
representation of the DDG. Similar to the CFG DOT printer, this
functionality is provided under an option called -dot-ddg and can
be generated in a less verbose mode under -dot-ddg-only option.

Differential Revision: https://reviews.llvm.org/D90159
2020-12-14 16:41:14 -05:00
Zequan Wu b5216b2950 [PGO] Enable preinline and cleanup when optimize for size
Differential Revision: https://reviews.llvm.org/D91673
2020-12-10 12:29:17 -08:00
Arthur Eubanks ff7e1da68f [NPM] Support -fmerge-functions
I tried to put it in the same place in the pipeline as the legacy PM.

Fixes PR48399.

Reviewed By: asbirlea, nikic

Differential Revision: https://reviews.llvm.org/D93002
2020-12-10 11:45:08 -08:00
Anna Thomas 29356e3279 [ScalarizeMaskedMemIntrin] Add new PM support
This patch adds new PM support for the pass and the pass can be now used
during middle-end transforms. The old pass is remamed to
ScalarizeMaskedMemIntrinLegacyPass.

Reviewed-By: skatkov, aeubanks
Differential Revision: https://reviews.llvm.org/D92743
2020-12-08 17:15:22 -05:00
Arthur Eubanks 2f0de58294 [NewPM] Support --print-before/after in NPM
This changes --print-before/after to be a list of strings rather than
legacy passes. (this also has the effect of not showing the entire list
of passes in --help-hidden after --print-before/after, which IMO is
great for making it less verbose).

Currently PrintIRInstrumentation passes the class name rather than pass
name to llvm::shouldPrintBeforePass(), meaning
llvm::shouldPrintBeforePass() never functions as intended in the NPM.
There is no easy way of converting class names to pass names outside of
within an instance of PassBuilder.

This adds a map of pass class names to their short names in
PassRegistry.def within PassInstrumentationCallbacks. It is populated
inside the constructor of PassBuilder, which takes a
PassInstrumentationCallbacks.

Add a pointer to PassInstrumentationCallbacks inside
PrintIRInstrumentation and use the newly created map.

This is a bit hacky, but I can't think of a better way since the short
id to class name only exists within PassRegistry.def. This also doesn't
handle passes not in PassRegistry.def but rather added via
PassBuilder::registerPipelineParsingCallback().

llvm/test/CodeGen/Generic/print-after.ll doesn't seem very useful now
with this change.

Reviewed By: ychen, jamieschmeiser

Differential Revision: https://reviews.llvm.org/D87216
2020-12-03 16:52:14 -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
Hongtao Yu c083fededf [CSSPGO] A Clang switch -fpseudo-probe-for-profiling for pseudo-probe instrumentation.
This change introduces a new clang switch `-fpseudo-probe-for-profiling` to enable AutoFDO with pseudo instrumentation. Please refer to https://reviews.llvm.org/D86193 for the whole story.

One implication from pseudo-probe instrumentation is that the profile is now sensitive to CFG changes. We perform the pseudo instrumentation very early in the pre-LTO pipeline, before any CFG transformation. This ensures that the CFG instrumented and annotated is stable and optimization-resilient.

The early instrumentation also allows the inliner to duplicate probes for inlined instances. When a probe along with the other instructions of a callee function are inlined into its caller function, the GUID of the callee function goes with the probe. This allows samples collected on inlined probes to be reported for the original callee function.

Reviewed By: wmi

Differential Revision: https://reviews.llvm.org/D86502
2020-11-30 10:16:54 -08:00
Hongtao Yu 64fa8cce22 [CSSPGO] Pseudo probe instrumentation pass
This change introduces a pseudo probe instrumentation pass for block instrumentation. Please refer to https://reviews.llvm.org/D86193 for the whole story.

Given the following LLVM IR:

```
define internal void @foo2(i32 %x, void (i32)* %f) !dbg !4 {
bb0:
  %cmp = icmp eq i32 %x, 0
   br i1 %cmp, label %bb1, label %bb2
bb1:
   br label %bb3
bb2:
   br label %bb3
bb3:
   ret void
}
```

The instrumented IR will look like below. Note that each llvm.pseudoprobe intrinsic call represents a pseudo probe at a block, of which the first parameter is the GUID of the probe’s owner function and the second parameter is the probe’s ID.

```
define internal void @foo2(i32 %x, void (i32)* %f) !dbg !4 {
bb0:
   %cmp = icmp eq i32 %x, 0
   call void @llvm.pseudoprobe(i64 837061429793323041, i64 1)
   br i1 %cmp, label %bb1, label %bb2
bb1:
   call void @llvm.pseudoprobe(i64 837061429793323041, i64 2)
   br label %bb3
bb2:
   call void @llvm.pseudoprobe(i64 837061429793323041, i64 3)
   br label %bb3
bb3:
   call void @llvm.pseudoprobe(i64 837061429793323041, i64 4)
   ret void
}
```

Reviewed By: wmi

Differential Revision: https://reviews.llvm.org/D86499
2020-11-30 10:16:54 -08:00
Andrew Litteken a8a43b6338 Revert "[IRSim][IROutliner] Adding the extraction basics for the IROutliner."
Reverting commit due to address sanitizer errors.

> Extracting the similar regions is the first step in the IROutliner.
> 
> Using the IRSimilarityIdentifier, we collect the SimilarityGroups and
> sort them by how many instructions will be removed.  Each
> IRSimilarityCandidate is used to define an OutlinableRegion.  Each
> region is ordered by their occurrence in the Module and the regions that
> are not compatible with previously outlined regions are discarded.
> 
> Each region is then extracted with the CodeExtractor into its own
> function.
> 
> We test that correctly extract in:
> test/Transforms/IROutliner/extraction.ll
> test/Transforms/IROutliner/address-taken.ll
> test/Transforms/IROutliner/outlining-same-globals.ll
> test/Transforms/IROutliner/outlining-same-constants.ll
> test/Transforms/IROutliner/outlining-different-structure.ll
> 
> Reviewers: paquette, jroelofs, yroux
> 
> Differential Revision: https://reviews.llvm.org/D86975

This reverts commit bf899e8913.
2020-11-27 19:55:57 -06:00
Andrew Litteken bf899e8913 [IRSim][IROutliner] Adding the extraction basics for the IROutliner.
Extracting the similar regions is the first step in the IROutliner.

Using the IRSimilarityIdentifier, we collect the SimilarityGroups and
sort them by how many instructions will be removed.  Each
IRSimilarityCandidate is used to define an OutlinableRegion.  Each
region is ordered by their occurrence in the Module and the regions that
are not compatible with previously outlined regions are discarded.

Each region is then extracted with the CodeExtractor into its own
function.

We test that correctly extract in:
test/Transforms/IROutliner/extraction.ll
test/Transforms/IROutliner/address-taken.ll
test/Transforms/IROutliner/outlining-same-globals.ll
test/Transforms/IROutliner/outlining-same-constants.ll
test/Transforms/IROutliner/outlining-different-structure.ll

Reviewers: paquette, jroelofs, yroux

Differential Revision: https://reviews.llvm.org/D86975
2020-11-27 19:08:29 -06:00
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 aff058b1a9 Reland [CGSCC] Detect devirtualization in more cases
The devirtualization wrapper misses cases where if it wraps a pass
manager, an individual pass may devirtualize an indirect call created by
a previous pass. For example, inlining may create a new indirect call
which is devirtualized by instcombine. Currently the devirtualization
wrapper will not see that because it only checks cgscc edges at the very
beginning and end of the pass (manager) it wraps.

This fixes some tests testing this exact behavior in the legacy PM.

Instead of checking WeakTrackingVHs for CallBases at the very beginning
and end of the pass it wraps, check every time
updateCGAndAnalysisManagerForPass() is called.

check-llvm and check-clang with -abort-on-max-devirt-iterations-reached
on by default doesn't show any failures outside of tests specifically
testing it so it doesn't needlessly rerun passes more than necessary.
(The NPM -O2/3 pipeline run the inliner/function simplification pipeline
under a devirtualization repeater pass up to 4 times by default).

http://llvm-compile-time-tracker.com/?config=O3&stat=instructions&remote=aeubanks
shows that 7zip has ~1% compile time regression. I looked at it and saw
that there indeed was devirtualization happening that was not previously
caught, so now it reruns the CGSCC pipeline on some SCCs, which is WAI.

The initial land assumed CallBase WeakTrackingVHs would always be
CallBases, but they can be RAUW'd with undef.

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D89587
2020-11-23 21:28:59 -08:00
Arthur Eubanks 6a2799cf8e Revert "[CGSCC] Detect devirtualization in more cases"
This reverts commit 14a68b4aa9.

Causes building self hosted clang to crash when using NPM.
2020-11-23 13:21:05 -08:00
Arthur Eubanks 3c811ce4f3 [NPM] Share pass building options with legacy PM
We should share options when possible.

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D91741
2020-11-23 13:04:05 -08:00
Arthur Eubanks 7167e5203a Port -print-memderefs to NPM
There is lots of code duplication, but hopefully it won't matter soon.

Reviewed By: ychen

Differential Revision: https://reviews.llvm.org/D91683
2020-11-23 11:56:22 -08:00