Summary:
This updates the Inliner to only add a single Optimization
Remark when Inlining, rather than an Analysis Remark and an
Optimization Remark.

Fixes https://bugs.llvm.org/show_bug.cgi?id=33786

Reviewers: anemet, davidxl, chandlerc

Reviewed By: anemet

Subscribers: haicheng, fhahn, mehdi_amini, dblaikie, llvm-commits, eraman

Differential Revision: https://reviews.llvm.org/D36054

llvm-svn: 311273

Summary:
Follow up to fix in r311023, which fixed the case where the combined
index is written to disk. The same samplePGO logic exists for the
in-memory index when computing imports, so we need to filter out
GlobalVariable summaries there too.

Reviewers: davidxl

Subscribers: inglorion, llvm-commits

Differential Revision: https://reviews.llvm.org/D36919

llvm-svn: 311254

Differential Revision: https://reviews.llvm.org/D34163

llvm-svn: 310885

Updating remark API to newer OptimizationDiagnosticInfo API. This
allows remarks to show up in diagnostic yaml file, and enables use
of opt-viewer tool.

Hotness information for remarks (L505 and L751) do not display hotness
information, most likely due to profile information not being
propagated yet. Unsure if this is the desired outcome.

Patch by Tarun Rajendran.

Differential Revision: https://reviews.llvm.org/D36127

llvm-svn: 310763

llvm-svn: 310737

llvm-svn: 310453

The frontend may have requested a higher alignment for any reason, and
downstream optimizations may already have taken advantage of it.  We
should keep the same alignment when moving the allocation from the
parameter area to the local variable area.

Fixes PR34038

llvm-svn: 310071

llvm-svn: 310021

llvm-svn: 310020

This is similar to what we are doing in "regular" SROA and creates
DW_OP_LLVM_fragment operations to describe the resulting variables.

rdar://problem/33654891

llvm-svn: 310014

infinite-inlining across multiple runs of the inliner by keeping a tiny
history of internal-to-SCC inlining decisions.

This is still a bit gross, but I don't yet have any fundamentally better
ideas and numerous people are blocked on this to use new PM and ThinLTO
together.

The core of the idea is to detect when we are about to do an inline that
has a chance of re-splitting an SCC which we have split before with
a similar inlining step. That is a critical component in the inlining
forming a cycle and so far detects all of the various cyclic patterns
I can come up with as well as the original real-world test case (which
comes from a ThinLTO build of libunwind).

I've added some tests that I think really demonstrate what is going on
here. They are essentially state machines that march the inliner through
various steps of a cycle and check that we stop when the cycle is closed
and that we actually did do inlining to form that cycle.

A lot of thanks go to Eric Christopher and Sanjoy Das for the help
understanding this issue and improving the test cases.

The biggest "yuck" here is the layering issue -- the CGSCC pass manager
is providing somewhat magical state to the inliner for it to use to make
itself converge. This isn't great, but I don't honestly have a lot of
better ideas yet and at least seems nicely isolated.

I have tested this patch, and it doesn't block *any* inlining on the
entire LLVM test suite and SPEC, so it seems sufficiently narrowly
targeted to the issue at hand.

We have come up with hypothetical issues that this patch doesn't cover,
but so far none of them are practical and we don't have a viable
solution yet that covers the hypothetical stuff, so proceeding here in
the interim. Definitely an area that we will be back and revisiting in
the future.

Differential Revision: https://reviews.llvm.org/D36188

llvm-svn: 309784

D33925 added a control flow simplification for -O2 --lto-O0 builds that
manually splits blocks and reassigns conditional branches but does not
correctly update phi nodes. If the else case being branched to had
incoming phi nodes the control-flow simplification would leave phi nodes
in that BB with an unhandled predecessor.

Patch by Vlad Tsyrklevich!

Differential Revision: https://reviews.llvm.org/D36012

llvm-svn: 309621

Summary:
Since  r293359, most dump() function are only defined when
`!defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)` holds. print() functions
only used by dump() functions are now unused in release builds,
generating lots of warnings. This patch only defines some print()
functions if they are used.

Reviewers: MatzeB

Reviewed By: MatzeB

Subscribers: arsenm, mzolotukhin, nhaehnle, llvm-commits

Differential Revision: https://reviews.llvm.org/D35949

llvm-svn: 309553

Summary: The original 3.0 hot mupltiplier is too small, and would prevent hot callsites from being inline. This patch increases the hot multilier to 10.0

Reviewers: davidxl, tejohnson

Reviewed By: tejohnson

Subscribers: llvm-commits, sanjoy

Differential Revision: https://reviews.llvm.org/D35969

llvm-svn: 309344

The alias support was dead code since 2011. It was last touched
in r124182, where it was reintroduced after being removed
in r110434, and since then it was gated behind a HasGlobalAliases
flag that was permanently stuck as `false`.

It is also broken. I'm not sure if it bitrotted or was just broken
in the first place because it appears to have never been tested,
but the following IR results in a crash:

    define internal i32 @a(i32 %a, i32 %b) unnamed_addr {
      %c = add i32 %a, %b
      %d = xor i32 %a, %c
      ret i32 %c
    }

    define internal i32 @b(i32 %a, i32 %b) unnamed_addr {
      %c = add i32 %a, %b
      %d = xor i32 %a, %c
      ret i32 %c
    }

It seems safe to remove buggy untested code that no one cared about
for seven years.

Differential Revision: https://reviews.llvm.org/D34802

llvm-svn: 309313

This change makes GCC7 happy again.

llvm-svn: 309305

Summary:
Until a more advanced version of importing can be implemented for
aliases (one that imports an alias as an available_externally definition
of the aliasee), skip the narrow subset of cases that was possible but
came at a cost: aliases of linkonce_odr functions could be imported
because the linkonce_odr function could be safely duplicated from the
source module. This came/comes at the cost of not being able to 'home'
imported linkonce functions (they had to be emitted linkonce_odr in all
the destination modules (even if they weren't used by an alias) rather
than as available_externally - causing extra object size).

Tangentially, this also was the only reason ThinLTO would emit multiple
CUs in to the resulting DWARF - which happens to be a problem for
Fission (there's a fix for this in GDB but not released yet, etc).
(actually it's not the only reason - but I'm sending a patch to fix the
other reason shortly)

There's no reason to believe this particularly narrow alias importing
was especially/meaningfully important, only that it was /possible/ to
implement in this way. When a more general solution is done, it should
still satisfy the DWARF concerns above, since the import will still be
available_externally, and thus not create extra CUs.

Since now all aliases are treated the same, I removed/simplified some
test cases since they were testing corner cases where there are no
longer any corners.

Reviewers: tejohnson, mehdi_amini

Differential Revision: https://reviews.llvm.org/D35875

llvm-svn: 309278

Summary: Currently the ThinLTO minimized bitcode file only strip the debug info, but there is still a lot of information in the minimized bit code file that will be not used for thin linker. In this patch, most of the extra information is striped to reduce the minimized bitcode file. Now only ModuleVersion, ModuleInfo, ModuleGlobalValueSummary, ModuleHash, Symtab and Strtab are left. Now the minimized bitcode file size is reduced to 15%-30% of the debug info stripped bitcode file size.

Reviewers: danielcdh, tejohnson, pcc

Reviewed By: pcc

Subscribers: mehdi_amini, aprantl, inglorion, eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D35334

llvm-svn: 308760

Previously we were (mis)handling jump table members with a prevailing
definition in a full LTO module and a non-prevailing definition in a
ThinLTO module by dropping type metadata on those functions entirely,
which would cause type tests involving such functions to fail.

This patch causes us to drop metadata only if we are about to replace
it with metadata from cfi.functions.

We also want to replace metadata for available_externally functions,
which can arise in the opposite scenario (prevailing ThinLTO
definition, non-prevailing full LTO definition). The simplest way
to handle that is to remove the definition; there's little value in
keeping it around at this point (i.e. after most optimization passes
have already run) and later code will try to use the function's linkage
to create an alias, which would result in invalid IR if the function
is available_externally.

Fixes PR33832.

Differential Revision: https://reviews.llvm.org/D35604

llvm-svn: 308642

Changing the type of an intrinsic may invalidate the IR.

Differential Revision: https://reviews.llvm.org/D35593

llvm-svn: 308500

functions.

In the prior commit, we provide ordering to the LCG between functions
and library function definitions that they might begin to call through
transformations. But we still would delete these library functions from
the call graph if they became dead during inlining.

While this immediately crashed, it also exposed a loss of information.
We shouldn't remove definitions of library functions that can still
usefully participate in the LCG-powered CGSCC optimization process. If
new call edges are formed, we want to have definitions to be called.

We can still remove these functions if truly dead using global-dce, etc,
but removing them during the CGSCC walk is premature.

This fixes a crash in the new PM when optimizing some unusual libraries
that end up with "internal" lib functions such as the code in the "R"
language's libraries.

llvm-svn: 308417

This reverts commit r308114 (and follow on fixes to test).

There is a linking failure in a ThinLTO bot:
http://green.lab.llvm.org/green/job/clang-stage2-configure-Rthinlto_build/3663/

(and undefined reference). It seems like it must be a second order
effect of the heuristic change I made, and may take some time to try
to reproduce locally and track down. Therefore, reverting for now.

llvm-svn: 308206

This restores r308078/r308079 with a fix for bot non-determinisim (make
sure we run llvm-lto in single threaded mode so the debug output doesn't get
interleaved).

llvm-svn: 308114

that appears to exhibit non-determinism and is flaking on the bots
pretty consistently.

r308078: [ThinLTO] Ensure we always select the same function copy to import
r308079: Require asserts in new test that uses debug flag
llvm-svn: 308095

Summary:
Check if the first eligible callee is under the instruction threshold.
Checking this on the first eligible callee ensures that we don't end
up selecting different callees to import when we invoke this routine
with different thresholds due to reaching the callee via paths that
are shallower or hotter (when there are multiple copies, i.e. with
weak or linkonce linkage). We don't want to leave the decision of which
copy to import up to the backend.

Reviewers: mehdi_amini

Subscribers: inglorion, fhahn, llvm-commits

Differential Revision: https://reviews.llvm.org/D35436

llvm-svn: 308078

Summary:
DominatorTreeBase used to have IsPostDominators (bool) member to indicate if the tree is a dominator or a postdominator tree. This made it possible to switch between the two 'modes' at runtime, but it isn't used in practice anywhere.

This patch makes IsPostDominator a template argument. This way, it is easier to switch between different algorithms at compile-time based on this argument and design external utilities around it. It also makes it impossible to incidentally assign a postdominator tree to a dominator tree (and vice versa), and to further simplify template code in GenericDominatorTreeConstruction.

Reviewers: dberlin, sanjoy, davide, grosser

Reviewed By: dberlin

Subscribers: mzolotukhin, llvm-commits

Differential Revision: https://reviews.llvm.org/D35315

llvm-svn: 308040

This commit reapplies r307215 now that we found out and fixed
the cause of the cfi test failure (in r307871).

llvm-svn: 307920

This normally indicates mixed CFI + non-CFI compilation, and will
result in us treating the function in the same way as a function
defined outside of the LTO unit.

Part of PR33752.

Differential Revision: https://reviews.llvm.org/D35281

llvm-svn: 307744

[GlobalOpt] Remove unreachable blocks before optimizing a function.
While the change is presumably correct, it exposes a latent bug
in DI which breaks on of the CFI checks. I'll analyze it further
and try to understand what's going on.

llvm-svn: 307729

  OpenCL 2.0 introduces the notion of memory scopes in atomic operations to
  global and local memory. These scopes restrict how synchronization is
  achieved, which can result in improved performance.

  This change extends existing notion of synchronization scopes in LLVM to
  support arbitrary scopes expressed as target-specific strings, in addition to
  the already defined scopes (single thread, system).

  The LLVM IR and MIR syntax for expressing synchronization scopes has changed
  to use *syncscope("<scope>")*, where <scope> can be "singlethread" (this
  replaces *singlethread* keyword), or a target-specific name. As before, if
  the scope is not specified, it defaults to CrossThread/System scope.

  Implementation details:
    - Mapping from synchronization scope name/string to synchronization scope id
      is stored in LLVM context;
    - CrossThread/System and SingleThread scopes are pre-defined to efficiently
      check for known scopes without comparing strings;
    - Synchronization scope names are stored in SYNC_SCOPE_NAMES_BLOCK in
      the bitcode.

Differential Revision: https://reviews.llvm.org/D21723

llvm-svn: 307722

querying for analysis results on a function declaration rather than
a definition.

The only reason this worked previously is by chance -- because the way
we got alias analysis results with the legacy PM, we happened to not
compute a dominator tree and so we happened to not hit an assert even
though it didn't make any real sense. Now we bail out before trying to
compute alias analysis so that we don't hit these asserts.

llvm-svn: 307625

Summary:
This solves PR33641.

When removing a dead argument we must also handle possibly existing calls
to llvm.dbg.value that use the removed argument. Now we change the use
of the otherwise dead argument to an undef for some other pass to cleanup
later.

If the calls are left untouched, they will later on cause errors:
 "function-local metadata used in wrong function"
since the ArgumentPromotion rewrites the code by creating a new function
with the wanted signature, but the metadata is not recreated so the new
function may then erroneously use metadata from the old function.

Reviewers: mstorsjo, rnk, arsenm

Reviewed By: rnk

Subscribers: wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D34874

llvm-svn: 307521

the invalidation propagation logic from an SCC to a Function.

I wrote the infrastructure to test this but didn't actually use it in
the unit test where it was designed to be used. =[ My bad. Once
I actually added it to the test case I discovered that it also hadn't
been properly implemented, so I've implemented it. The logic in the FAM
proxy for an SCC pass to propagate invalidation follows the same ideas
as the FAM proxy for a Module pass, but the implementation is a bit
different to reflect the fact that it is forwarding just for an SCC.

However, implementing this correctly uncovered a surprising "bug" (it
was conservatively correct but relatively very expensive) in how we
handle invalidation when splitting one SCC into multiple SCCs. We did an
eager invalidation when in reality we should be deferring invaliadtion
for the *current* SCC to the CGSCC pass manager and just invaliating the
newly constructed SCCs. Otherwise we end up invalidating too much too
soon. This was exposed by the inliner test case that I've updated. Now,
we invalidate *just* the split off '(test1_f)' SCC when doing the CG
update, and then the inliner finishes and invalidates the '(test1_g,
test1_h)' SCC's analyses. The first few attempts at fixing this hit
still more bugs, but all of those are covered by existing tests. For
example, the inliner should also preserve the FAM proxy to avoid
unnecesasry invalidation, and this is safe because the CG update
routines it uses handle any necessary adjustments to the FAM proxy.

Finally, the unittests for the CGSCC pass manager needed a bunch of
updates where we weren't correctly preserving the FAM proxy because it
hadn't been fully implemented and failing to preserve it didn't matter.

Note that this doesn't yet fix the current crasher due to MemSSA finding
a stale dominator tree, but without this the fix to that crasher doesn't
really make any sense when testing because it relies on the proxy
behavior.

llvm-svn: 307487

Summary: For interative sample-pgo, if a hot call site is inlined in the profiling binary, we should inline it in before profile annotation in the backend. Before that, the compile phase first collects all GUIDs that needs to be imported and creates virtual "hot" call edge in the summary. However, "hot" is not good enough to guarantee the callsites get inlined. This patch introduces "critical" call edge, and assign much higher importing threshold for those edges.

Reviewers: tejohnson

Reviewed By: tejohnson

Subscribers: sanjoy, mehdi_amini, llvm-commits, eraman

Differential Revision: https://reviews.llvm.org/D35096

llvm-svn: 307439

Pointed out by Teresa!

llvm-svn: 307305

This is the same as r304719 but for ThinLTO.
The substantial difference is that in this case we don't have
whole visibility, just the summary.
In the LTO case, when we got the resolution for the input file we
could just see if the linker told us whether a symbol was linker
redefined (using --wrap or --defsym) and switch the linkage directly
for the GV.

Here, we have the summary. So, we record that the linkage changed
from <whatever it was> to $weakany to prevent IPOs across this symbol
boundaries and actually just switch the linkage at FunctionImport time.

This patch should also fixes the lld bits (as all the scaffolding for
communicating if a symbol is linker redefined should be there & should
be the same), but I'll make sure to add some tests there as well.

Fixes PR33192.

Differential Revision:  https://reviews.llvm.org/D35064

llvm-svn: 307303

Summary:
GlobalExtensions is dereferenced twice, once for iteration and then a check if it is empty.
As a ManagedStatic this dereference forces it's construction which is unnecessary.

Reviewers: efriedma, davide, mehdi_amini

Reviewed By: mehdi_amini

Subscribers: chapuni, llvm-commits, mehdi_amini

Differential Revision: https://reviews.llvm.org/D33381

llvm-svn: 307229

LLVM's definition of dominance allows instructions that are cyclic
in unreachable blocks, e.g.:

  %pat = select i1 %condition, @global, i16* %pat

because any instruction dominates an instruction in a block that's
not reachable from entry.
So, remove unreachable blocks from the function, because a) there's
no point in analyzing them and b) GlobalOpt should otherwise grow
some more complicated logic to break these cycles.

Differential Revision:  https://reviews.llvm.org/D35028

llvm-svn: 307215

It served us well, helped kick-start much of the vectorization efforts
in LLVM, etc. Its time has come and past. Back in 2014:
http://lists.llvm.org/pipermail/llvm-dev/2014-November/079091.html

Time to actually let go and move forward. =]

I've updated the release notes both about the removal and the
deprecation of the corresponding C API.

llvm-svn: 306797

Summary: This patch hooks up SampleProfileLoaderPass with the new PM.

Reviewers: chandlerc, davidxl, davide, tejohnson

Reviewed By: chandlerc, tejohnson

Subscribers: tejohnson, llvm-commits, sanjoy

Differential Revision: https://reviews.llvm.org/D34720

llvm-svn: 306763