Commit Graph

396 Commits

Author SHA1 Message Date
David Blaikie 2be3922807 Fix a couple of layering violations in Transforms
Remove #include of Transforms/Scalar.h from Transform/Utils to fix layering.

Transforms depends on Transforms/Utils, not the other way around. So
remove the header and the "createStripGCRelocatesPass" function
declaration (& definition) that is unused and motivated this dependency.

Move Transforms/Utils/Local.h into Analysis because it's used by
Analysis/MemoryBuiltins.cpp.

llvm-svn: 328165
2018-03-21 22:34:23 +00:00
Daniel Neilson a894201313 [InlineFunction] Update deprecated use of IRBuilder CreateMemCpy (NFC)
Summary:
This change is part of step five in the series of changes to remove alignment argument from
memcpy/memmove/memset in favour of alignment attributes. In particular, this changes the
InlineFunction pass to ceause using the old IRBuilder CreateMemCpy single-alignment API
in favour of the new API that allows setting source and destination alignments independently.

Steps:
Step 1) Remove alignment parameter and create alignment parameter attributes for
memcpy/memmove/memset. ( rL322965, rC322964, rL322963 )
Step 2) Expand the IRBuilder API to allow creation of memcpy/memmove with differing
source and dest alignments. ( rL323597 )
Step 3) Update Clang to use the new IRBuilder API. ( rC323617 )
Step 4) Update Polly to use the new IRBuilder API. ( rL323618 )
Step 5) Update LLVM passes that create memcpy/memmove calls to use the new IRBuilder API,
and those that use use MemIntrinsicInst::[get|set]Alignment() to use [get|set]DestAlignment()
and [get|set]SourceAlignment() instead. ( rL323886, rL323891, rL324148, rL324273, rL324278 )
Step 6) Remove the single-alignment IRBuilder API for memcpy/memmove, and the
MemIntrinsicInst::[get|set]Alignment() methods.

Reference
   http://lists.llvm.org/pipermail/llvm-dev/2015-August/089384.html
   http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20151109/312083.html

llvm-svn: 324384
2018-02-06 19:14:31 +00:00
Florian Hahn 8f804fc07d [InlineFunction] Set arg attrs even if there only are VarArg attrs.
When using the partial inliner, we might have attributes for forwarded
varargs, but the CodeExtractor does not create an empty argument
attribute set for regular arguments in that case, because it does not know
of the additional arguments. So in case we have attributes for VarArgs, we
also have to make sure we create (empty) attributes for all regular arguments.

This fixes PR36210.

llvm-svn: 324197
2018-02-04 18:27:47 +00:00
Easwaran Raman e5b8de2f1f Add a ProfileCount class to represent entry counts.
Summary:
The class wraps a uint64_t and an enum to represent the type of profile
count (real and synthetic) with some helper methods.

Reviewers: davidxl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D41883

llvm-svn: 322771
2018-01-17 22:24:23 +00:00
Florian Hahn a82eef2363 [InlineFunction] Preserve calling convention when forwarding VarArgs.
Reviewers: efriedma, rnk, davide

Reviewed By: rnk, davide

Differential Revision: https://reviews.llvm.org/D41556

llvm-svn: 321943
2018-01-06 20:56:27 +00:00
Florian Hahn de10e6e064 [InlineFunction] Preserve attributes when forwarding VarArgs.
Reviewers: rnk, efriedma

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D41555

llvm-svn: 321942
2018-01-06 20:46:00 +00:00
Florian Hahn 80788d8088 [InlineFunction] Inline vararg functions that do not access varargs.
If the varargs are not accessed by a function, we can inline the
function.

Reviewers: dblaikie, chandlerc, davide, efriedma, rnk, hfinkel

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D41335

llvm-svn: 321940
2018-01-06 19:45:40 +00:00
Florian Hahn c5bebffe4f [InlineFunction] Set debug loc for call to forward varargs.
Reviewers: aprantl, dblaikie, rnk

Reviewed By: rnk

Subscribers: eraman, llvm-commits, JDevlieghere

Differential Revision: https://reviews.llvm.org/D40432

llvm-svn: 320252
2017-12-09 14:25:33 +00:00
Adrian Prantl d13170174c Generalize llvm::replaceDbgDeclare and actually support the use-case that
is mentioned in the documentation (inserting a deref before the plus_uconst).

llvm-svn: 320203
2017-12-08 21:58:18 +00:00
Florian Hahn 115d99162c [InlineFunction] Only replace call if there are VarArgs to forward.
Summary:
There is no need to replace the original call instruction if no
 VarArgs need to be forwarded. 

Reviewers: davide, rnk, majnemer, efriedma

Reviewed By: efriedma

Subscribers: eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D40412

llvm-svn: 319947
2017-12-06 19:47:24 +00:00
Arnold Schwaighofer d9e710984d Inliner: Don't mark notail calls with the 'tail' attribute
enum TailCallKind { TCK_None = 0, TCK_Tail = 1, TCK_MustTail = 2,
                    TCK_NoTail = 3 };

TCK_NoTail is greater than TCK_Tail so taking the min does not do the
correct thing.

rdar://35639547

llvm-svn: 319075
2017-11-27 19:03:40 +00:00
Florian Hahn 0e9dec672d [PartialInliner] Inline vararg functions that forward varargs.
Summary:
This patch extends the partial inliner to support inlining parts of
vararg functions, if the vararg handling is done in the outlined part.

It adds a `ForwardVarArgsTo` argument to InlineFunction. If it is
non-null, all varargs passed to the inlined function will be added to
all calls to `ForwardVarArgsTo`.

The partial inliner takes care to only pass `ForwardVarArgsTo` if the
varargs handing is done in the outlined function. It checks that vastart
is not part of the function to be inlined.

`test/Transforms/CodeExtractor/PartialInlineNoInline.ll` (already part
of the repo) checks we do not do partial inlining if vastart is used in
a basic block that will be inlined.

Reviewers: davide, davidxl, grosser

Reviewed By: davide, davidxl, grosser

Subscribers: gyiu, grosser, eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D39607

llvm-svn: 318028
2017-11-13 10:35:52 +00:00
Eugene Zelenko 6cadde7f40 [Transforms] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).
llvm-svn: 316034
2017-10-17 21:27:42 +00:00
Chandler Carruth 6bda14b313 Sort the remaining #include lines in include/... and lib/....
I did this a long time ago with a janky python script, but now
clang-format has built-in support for this. I fed clang-format every
line with a #include and let it re-sort things according to the precise
LLVM rules for include ordering baked into clang-format these days.

I've reverted a number of files where the results of sorting includes
isn't healthy. Either places where we have legacy code relying on
particular include ordering (where possible, I'll fix these separately)
or where we have particular formatting around #include lines that
I didn't want to disturb in this patch.

This patch is *entirely* mechanical. If you get merge conflicts or
anything, just ignore the changes in this patch and run clang-format
over your #include lines in the files.

Sorry for any noise here, but it is important to keep these things
stable. I was seeing an increasing number of patches with irrelevant
re-ordering of #include lines because clang-format was used. This patch
at least isolates that churn, makes it easy to skip when resolving
conflicts, and gets us to a clean baseline (again).

llvm-svn: 304787
2017-06-06 11:49:48 +00:00
Teresa Johnson 525dcb617b Fix update VP metadata after inlining for instrumentation PGO
Summary:
With instrumentation profiling, when updating the VP metadata after
an inline, VP metadata on the inlined copy was inadvertantly having
all counts zeroed out. This was causing indirect calls from code inlined
during the call step to be marked as cold in the ThinLTO summaries and
not imported.

The CallerBFI needs to be passed down so that the CallSiteCount can be
computed from the profile summary info. With Sample PGO this was working
since the count is extracted from the branch weight metadata on the
call being inlined (even before we stopped looking at metadata for
non-sample PGO in r302844 this largely wasn't working for instrumentation
PGO since only promoted indirect calls would be getting inlined and have
the metadata).

Added an instrumentation PGO test and renamed the sample PGO test.

Reviewers: danielcdh, eraman

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D33389

llvm-svn: 303574
2017-05-22 20:28:18 +00:00
Easwaran Raman f5f9160072 [ProfileSummary] Make getProfileCount a non-static member function.
This change is required because the notion of count is different for
sample profiling and getProfileCount will need to determine the
underlying profile type.

Differential revision: https://reviews.llvm.org/D33012

llvm-svn: 302597
2017-05-09 23:21:10 +00:00
Adrian Prantl c10d0e5ccd Make it illegal for two Functions to point to the same DISubprogram
As recently discussed on llvm-dev [1], this patch makes it illegal for
two Functions to point to the same DISubprogram and updates
FunctionCloner to also clone the debug info of a function to conform
to the new requirement. To simplify the implementation it also factors
out the creation of inlineAt locations from the Inliner into a
general-purpose utility in DILocation.

[1] http://lists.llvm.org/pipermail/llvm-dev/2017-May/112661.html
<rdar://problem/31926379>

Differential Revision: https://reviews.llvm.org/D32975

This reapplies r302469 with a fix for a bot failure (reparentDebugInfo
now checks for the case the orig and new function are identical).

llvm-svn: 302576
2017-05-09 19:47:37 +00:00
Hans Wennborg 66fb0d9768 Revert r302469 "Make it illegal for two Functions to point to the same DISubprogram"
This caused PR32977.

Original commit message:

> Make it illegal for two Functions to point to the same DISubprogram
>
> As recently discussed on llvm-dev [1], this patch makes it illegal for
> two Functions to point to the same DISubprogram and updates
> FunctionCloner to also clone the debug info of a function to conform
> to the new requirement. To simplify the implementation it also factors
> out the creation of inlineAt locations from the Inliner into a
> general-purpose utility in DILocation.
>
> [1] http://lists.llvm.org/pipermail/llvm-dev/2017-May/112661.html
> <rdar://problem/31926379>
>
> Differential Revision: https://reviews.llvm.org/D32975

llvm-svn: 302533
2017-05-09 14:44:15 +00:00
Adrian Prantl 200a5ef526 Make it illegal for two Functions to point to the same DISubprogram
As recently discussed on llvm-dev [1], this patch makes it illegal for
two Functions to point to the same DISubprogram and updates
FunctionCloner to also clone the debug info of a function to conform
to the new requirement. To simplify the implementation it also factors
out the creation of inlineAt locations from the Inliner into a
general-purpose utility in DILocation.

[1] http://lists.llvm.org/pipermail/llvm-dev/2017-May/112661.html
<rdar://problem/31926379>

Differential Revision: https://reviews.llvm.org/D32975

llvm-svn: 302469
2017-05-08 21:17:08 +00:00
Reid Kleckner 859f8b544a Make getParamAlignment use argument numbers
The method is called "get *Param* Alignment", and is only used for
return values exactly once, so it should take argument indices, not
attribute indices.

Avoids confusing code like:
  IsSwiftError = CS->paramHasAttr(ArgIdx, Attribute::SwiftError);
  Alignment  = CS->getParamAlignment(ArgIdx + 1);

Add getRetAlignment to handle the one case in Value.cpp that wants the
return value alignment.

This is a potentially breaking change for out-of-tree backends that do
their own call lowering.

llvm-svn: 301682
2017-04-28 20:34:27 +00:00
Daniel Berlin 4d0fe64ae3 Kill off the old SimplifyInstruction API by converting remaining users.
llvm-svn: 301673
2017-04-28 19:55:38 +00:00
Matt Arsenault 3c1fc768ed Allow DataLayout to specify addrspace for allocas.
LLVM makes several assumptions about address space 0. However,
alloca is presently constrained to always return this address space.
There's no real way to avoid using alloca, so without this
there is no way to opt out of these assumptions.

The problematic assumptions include:
- That the pointer size used for the stack is the same size as
  the code size pointer, which is also the maximum sized pointer.

- That 0 is an invalid, non-dereferencable pointer value.

These are problems for AMDGPU because alloca is used to
implement the private address space, which uses a 32-bit
index as the pointer value. Other pointers are 64-bit
and behave more like LLVM's notion of generic address
space. By changing the address space used for allocas,
we can change our generic pointer type to be LLVM's generic
pointer type which does have similar properties.

llvm-svn: 299888
2017-04-10 22:27:50 +00:00
David Blaikie 795dc94614 Fix UB found by -Wtautological-undefined-compare
llvm-svn: 298279
2017-03-20 18:01:07 +00:00
Dehao Chen e593049fb0 Updates branch_weights annotation for call instructions during inlining.
Summary: Inliner should update the branch_weights annotation to scale it to proper value.

Reviewers: davidxl, eraman

Reviewed By: eraman

Subscribers: zzheng, llvm-commits

Differential Revision: https://reviews.llvm.org/D30767

llvm-svn: 298270
2017-03-20 16:40:44 +00:00
Reid Kleckner 45707d4d5a Remove getArgumentList() in favor of arg_begin(), args(), etc
Users often call getArgumentList().size(), which is a linear way to get
the number of function arguments. arg_size(), on the other hand, is
constant time.

In general, the fact that arguments are stored in an iplist is an
implementation detail, so I've removed it from the Function interface
and moved all other users to the argument container APIs (arg_begin(),
arg_end(), args(), arg_size()).

Reviewed By: chandlerc

Differential Revision: https://reviews.llvm.org/D31052

llvm-svn: 298010
2017-03-16 22:59:15 +00:00
Adrian Prantl d4056501fb Revert "Strip debug info when inlining into a nodebug function."
This reverts commit r296488.

As noted by David Blaikie on llvm-commits, I overlooked the case of a
debug function being inlined into a nodebug function being inlined
into a debug function.

llvm-svn: 297163
2017-03-07 17:28:57 +00:00
Adrian Prantl 80d0c93436 Strip debug info when inlining into a nodebug function.
The LLVM backend cannot produce any debug info for an llvm::Function
without a DISubprogram attachment. When inlining a debug-info-carrying
function into a nodebug function, there is therefore no reason to keep
any debug info intrinsic calls or debug locations on the instructions.

This fixes a problem discovered in PR32042.

rdar://problem/30679307

llvm-svn: 296488
2017-02-28 16:58:13 +00:00
Hans Wennborg 2d5841fa73 Revert r296366 "[InlineFunction] add nonnull assumptions based on argument attributes"
It causes miscompiles e.g. during self-host of Clang (PR32082).

llvm-svn: 296398
2017-02-27 22:33:02 +00:00
Sanjay Patel 40975e05eb [InlineFunction] add nonnull assumptions based on argument attributes
This was suggested in D27855: have the inliner add assumptions, so we don't 
lose nonnull info provided by argument attributes.

This still doesn't solve PR28430 (dyn_cast), but this gets us closer.

https://reviews.llvm.org/D29999

llvm-svn: 296366
2017-02-27 18:13:48 +00:00
Sanjay Patel 288f075f8e [InlineFunction] use getFunction(); NFC
llvm-svn: 295185
2017-02-15 15:22:18 +00:00
Sanjay Patel 32d753cae3 [InlineFunction] use getCaller(); NFCI
llvm-svn: 295181
2017-02-15 15:08:38 +00:00
Sanjay Patel ada717e25b [InlineFunction] use range-for loop; NFCI
llvm-svn: 295179
2017-02-15 14:56:11 +00:00
Easwaran Raman 5a12f236c6 Fix a bug in caller's BFI update code after inlining.
Multiple blocks in the callee can be mapped to a single cloned block
since we prune the callee as we clone it. The existing code
iterates over the value map and clones the block frequency (and
eventually scales the frequencies of the cloned blocks). Value map's
iteration is not deterministic and so the cloned block might get the
frequency of any of the original blocks. The fix is to set the max of
the original frequencies to the cloned block. The first block in the
sequence must have this max frequency and, in the call context,
subsequent blocks must have its frequency.

Differential Revision: https://reviews.llvm.org/D29696

llvm-svn: 295115
2017-02-14 22:49:28 +00:00
Easwaran Raman 12585b0148 Improve PGO support for the new inliner
This adds the following to the new PM based inliner in PGO mode:

* Use block frequency analysis to derive callsite's profile count and use
that to adjust thresholds of hot and cold callsites.

* Incrementally update the BFI of the caller after a callee gets inlined
into it. This incremental update is only within an invocation of the run
method - BFI is not preserved across calls to run.
Update the function entry count of the callee after inlining it into a
caller.

* I've tuned the thresholds for the hot and cold callsites using a hacked
up version of the old inliner that explicitly computes BFI on a set of
internal benchmarks and spec. Once the new PM based pipeline stabilizes
(IIRC Chandler mentioned there are known issues) I'll benchmark this
again and adjust the thresholds if required.
Inliner PGO support.

Differential revision: https://reviews.llvm.org/D28331

llvm-svn: 292666
2017-01-20 22:44:04 +00:00
Sanjay Patel 65d533ca42 fix typo; NFC
llvm-svn: 290827
2017-01-02 19:05:11 +00:00
Sanjay Patel aea60846c4 [Inliner] remove unnecessary null checks from AddAlignmentAssumptions(); NFCI
We bail out on the 1st line if the assumption cache is not set, so there's
no need to check it after that.

llvm-svn: 290787
2016-12-31 17:54:05 +00:00
Chandler Carruth 0ee8bb11c3 [PM] Move the collection of call sites to a more appropriate place
inside of `InlineFunction`. Prior to this, call instructions are
specifically being rewritten and replaced within the inlined region,
invalidating some of the call sites.

Several of these regions are using the same technique to walk the
inlined region so this seems clearly safe up to this point.

I've also added a short circuit to the scan for call sites based on what
other code is doing.

With this, the most common crash I've found in the new inliner code is
fixed. I've turned it on for another test case that covers this
scenario.

I'll make my way through most of the other inliner test cases
just to get some easy coverage next.

llvm-svn: 290562
2016-12-27 01:24:50 +00:00
Chandler Carruth 1d96311447 [PM] Provide an initial, minimal port of the inliner to the new pass manager.
This doesn't implement *every* feature of the existing inliner, but
tries to implement the most important ones for building a functional
optimization pipeline and beginning to sort out bugs, regressions, and
other problems.

Notable, but intentional omissions:
- No alloca merging support. Why? Because it isn't clear we want to do
  this at all. Active discussion and investigation is going on to remove
  it, so for simplicity I omitted it.
- No support for trying to iterate on "internally" devirtualized calls.
  Why? Because it adds what I suspect is inappropriate coupling for
  little or no benefit. We will have an outer iteration system that
  tracks devirtualization including that from function passes and
  iterates already. We should improve that rather than approximate it
  here.
- Optimization remarks. Why? Purely to make the patch smaller, no other
  reason at all.

The last one I'll probably work on almost immediately. But I wanted to
skip it in the initial patch to try to focus the change as much as
possible as there is already a lot of code moving around and both of
these *could* be skipped without really disrupting the core logic.

A summary of the different things happening here:

1) Adding the usual new PM class and rigging.

2) Fixing minor underlying assumptions in the inline cost analysis or
   inline logic that don't generally hold in the new PM world.

3) Adding the core pass logic which is in essence a loop over the calls
   in the nodes in the call graph. This is a bit duplicated from the old
   inliner, but only a handful of lines could realistically be shared.
   (I tried at first, and it really didn't help anything.) All told,
   this is only about 100 lines of code, and most of that is the
   mechanics of wiring up analyses from the new PM world.

4) Updating the LazyCallGraph (in the new PM) based on the *newly
   inlined* calls and references. This is very minimal because we cannot
   form cycles.

5) When inlining removes the last use of a function, eagerly nuking the
   body of the function so that any "one use remaining" inline cost
   heuristics are immediately refined, and queuing these functions to be
   completely deleted once inlining is complete and the call graph
   updated to reflect that they have become dead.

6) After all the inlining for a particular function, updating the
   LazyCallGraph and the CGSCC pass manager to reflect the
   function-local simplifications that are done immediately and
   internally by the inline utilties. These are the exact same
   fundamental set of CG updates done by arbitrary function passes.

7) Adding a bunch of test cases to specifically target CGSCC and other
   subtle aspects in the new PM world.

Many thanks to the careful review from Easwaran and Sanjoy and others!

Differential Revision: https://reviews.llvm.org/D24226

llvm-svn: 290161
2016-12-20 03:15:32 +00:00
Daniel Jasper aec2fa352f Revert @llvm.assume with operator bundles (r289755-r289757)
This creates non-linear behavior in the inliner (see more details in
r289755's commit thread).

llvm-svn: 290086
2016-12-19 08:22:17 +00:00
Hal Finkel 3ca4a6bcf1 Remove the AssumptionCache
After r289755, the AssumptionCache is no longer needed. Variables affected by
assumptions are now found by using the new operand-bundle-based scheme. This
new scheme is more computationally efficient, and also we need much less
code...

llvm-svn: 289756
2016-12-15 03:02:15 +00:00
Andrea Di Biagio eff22832c0 [InlineFunction] Refactor code in function `fixupLineNumbers' as suggested by David in D27462. NFC
llvm-svn: 288901
2016-12-07 12:01:45 +00:00
Andrea Di Biagio 32d5aedd5b [InlineFunction] Do not propagate the callsite debug location to instructions inlined from functions with debug info.
When a function F is inlined, InlineFunction extends the debug location of every
instruction inlined from F by adding an InlinedAt.

However, if an instruction has a 'null' debug location, InlineFunction would
propagate the callsite debug location to it. This behavior existed since
revision 210459.

Revision 210459 was originally committed specifically to workaround the lack of
debug information for instructions inlined from intrinsic functions (which are
usually declared with attributes `__always_inline__, __nodebug__`).

The problem with revision 210459 is that it doesn't make any sort of distinction
between instructions inlined from a 'nodebug' function and instructions which
are inlined from a function built with debug info. This issue may lead to
incorrect stepping in the debugger.

This patch works under the assumption that a nodebug function does not have a
DISubprogram. When a function F is inlined into another function G,
InlineFunction checks if F has debug info associated with it.

For nodebug functions, the InlineFunction logic is unchanged (i.e. it would
still propagate the callsite debugloc to the inlined instructions). Otherwise,
InlineFunction no longer propagates the callsite debug location.

Differential Revision: https://reviews.llvm.org/D27462

llvm-svn: 288895
2016-12-07 10:37:26 +00:00
Kuba Brecka ddfdba3b01 [tsan] Add support for C++ exceptions into TSan (call __tsan_func_exit during unwinding), LLVM part
This adds support for TSan C++ exception handling, where we need to add extra calls to __tsan_func_exit when a function is exitted via exception mechanisms. Otherwise the shadow stack gets corrupted (leaked). This patch moves and enhances the existing implementation of EscapeEnumerator that finds all possible function exit points, and adds extra EH cleanup blocks where needed.

Differential Revision: https://reviews.llvm.org/D26177

llvm-svn: 286893
2016-11-14 21:41:13 +00:00
Arnold Schwaighofer c9277f40fd Inliner: Don't mark swifterror allocas with lifetime markers
This would create a bitcast use which fails the verifier: swifterror values may
only be used by loads, stores, and as function arguments.

rdar://28233244

llvm-svn: 281114
2016-09-09 22:40:27 +00:00
Joseph Tremoulet e92e0a9042 Fix inliner funclet unwind memoization
Summary:
The inliner may need to determine where a given funclet unwinds to,
and this determination may depend on other funclets throughout the
funclet tree.  The code that performs this walk in getUnwindDestToken
memoizes results to avoid redundant computations.  In the case that
a funclet's unwind destination is derived from its ancestor, there's
code to walk back down the tree from the ancestor updating the memo
map of its descendants to record the unwind destination.  This change
fixes that code to account for the case that some descendant has a
different unwind destination, which can happen if that unwind dest
is a descendant of the EHPad being queried and thus didn't determine
its unwind destination.

Also update test inline-funclets.ll, which is supposed to cover such
scenarios, to include a case that fails an assertion without this fix
but passes with it.

Fixes PR29151.


Reviewers: majnemer

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D24117

llvm-svn: 280610
2016-09-04 01:23:20 +00:00
Chandler Carruth 67fc52f067 [PM] Port the always inliner to the new pass manager in a much more
minimal and boring form than the old pass manager's version.

This pass does the very minimal amount of work necessary to inline
functions declared as always-inline. It doesn't support a wide array of
things that the legacy pass manager did support, but is alse ... about
20 lines of code. So it has that going for it. Notably things this
doesn't support:

- Array alloca merging
  - To support the above, bottom-up inlining with careful history
    tracking and call graph updates
- DCE of the functions that become dead after this inlining.
- Inlining through call instructions with the always_inline attribute.
  Instead, it focuses on inlining functions with that attribute.

The first I've omitted because I'm hoping to just turn it off for the
primary pass manager. If that doesn't pan out, I can add it here but it
will be reasonably expensive to do so.

The second should really be handled by running global-dce after the
inliner. I don't want to re-implement the non-trivial logic necessary to
do comdat-correct DCE of functions. This means the -O0 pipeline will
have to be at least 'always-inline,global-dce', but that seems
reasonable to me. If others are seriously worried about this I'd like to
hear about it and understand why. Again, this is all solveable by
factoring that logic into a utility and calling it here, but I'd like to
wait to do that until there is a clear reason why the existing
pass-based factoring won't work.

The final point is a serious one. I can fairly easily add support for
this, but it seems both costly and a confusing construct for the use
case of the always inliner running at -O0. This attribute can of course
still impact the normal inliner easily (although I find that
a questionable re-use of the same attribute). I've started a discussion
to sort out what semantics we want here and based on that can figure out
if it makes sense ta have this complexity at O0 or not.

One other advantage of this design is that it should be quite a bit
faster due to checking for whether the function is a viable candidate
for inlining exactly once per function instead of doing it for each call
site.

Anyways, hopefully a reasonable starting point for this pass.

Differential Revision: https://reviews.llvm.org/D23299

llvm-svn: 278896
2016-08-17 02:56:20 +00:00
David Majnemer 744a8753db Preserve the assumption cache more often
We were clearing it out in LoopUnswitch and InlineFunction instead of
attempting to preserve it.

llvm-svn: 278860
2016-08-16 22:07:32 +00:00
Reid Kleckner 6ee00a2602 [Inliner] Don't treat inalloca allocas as static
They aren't static, and moving them to the entry block across something
else will only result in tears.

Root cause of http://crbug.com/636558.

llvm-svn: 278571
2016-08-12 22:23:04 +00:00
Sean Silva ab6a683765 Avoid using a raw AssumptionCacheTracker in various inliner functions.
This unblocks the new PM part of River's patch in
https://reviews.llvm.org/D22706

Conveniently, this same change was needed for D21921 and so these
changes are just spun out from there.

llvm-svn: 276515
2016-07-23 04:22:50 +00:00
Benjamin Kramer 135f735af1 Apply clang-tidy's modernize-loop-convert to most of lib/Transforms.
Only minor manual fixes. No functionality change intended.

llvm-svn: 273808
2016-06-26 12:28:59 +00:00