Commit Graph

229 Commits

Author SHA1 Message Date
Fedor Sergeev 9c871764b9 [InlineCost] cleanup calculations of Cost and Threshold
Summary:
Doing better separation of Cost and Threshold.
Cost counts the abstract complexity of live instructions, while Threshold is an upper bound of complexity that inlining is comfortable to pay.
There are two parts:
     - huge 15K last-call-to-static bonus is no longer subtracted from Cost
       but rather is now added to Threshold.

       That makes much more sense, as the cost of inlining (Cost) is not changed by the fact
       that internal function is called once. It only changes the likelyhood of this inlining
       being profitable (Threshold).

     - bonus for calls proved-to-be-inlinable into callee is no longer subtracted from Cost
       but added to Threshold instead.

While calculations are somewhat different,  overall InlineResult should stay the same since Cost >= Threshold compares the same.

Reviewers: eraman, greened, chandlerc, yrouban, apilipenko
Reviewed By: apilipenko
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60740

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@364422 91177308-0d34-0410-b5e6-96231b3b80d8
2019-06-26 13:24:24 +00:00
Ben Dunbobbin c543215de3 [ThinLTO]LTO]Legacy] Fix dependent libraries support by adding querying of the IRSymtab
Dependent libraries support for the legacy api was committed in a
broken state (see: https://reviews.llvm.org/D60274). This was missed
due to the painful nature of having to integrate the changes into a
linker in order to test. This change implements support for dependent
libraries in the legacy LTO api:

- I have removed the current api function, which returns a single
string, and   added functions to access each dependent library
specifier individually.

- To reduce the testing pain, I have made the api functions as thin as
possible to   maximize coverage from llvm-lto.

- When doing ThinLTO the system linker will load the modules lazily
when scanning   the input files. Unfortunately, when modules are
lazily loaded there is no access   to module level named metadata. To
fix this I have added api functions that allow   querying the IRSymtab
for the dependent libraries. I hope to expand the api in the   future
so that, eventually, all the information needed by a client linker
during   scan can be retrieved from the IRSymtab.

Differential Revision: https://reviews.llvm.org/D62935

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@363140 91177308-0d34-0410-b5e6-96231b3b80d8
2019-06-12 11:07:56 +00:00
Ben Dunbobbin 7398f4a5f8 [ELF] Implement Dependent Libraries Feature
This patch implements a limited form of autolinking primarily designed to allow
either the --dependent-library compiler option, or "comment lib" pragmas (
https://docs.microsoft.com/en-us/cpp/preprocessor/comment-c-cpp?view=vs-2017) in
C/C++ e.g. #pragma comment(lib, "foo"), to cause an ELF linker to automatically
add the specified library to the link when processing the input file generated
by the compiler.

Currently this extension is unique to LLVM and LLD. However, care has been taken
to design this feature so that it could be supported by other ELF linkers.

The design goals were to provide:

- A simple linking model for developers to reason about.
- The ability to to override autolinking from the linker command line.
- Source code compatibility, where possible, with "comment lib" pragmas in other
  environments (MSVC in particular).

Dependent library support is implemented differently for ELF platforms than on
the other platforms. Primarily this difference is that on ELF we pass the
dependent library specifiers directly to the linker without manipulating them.
This is in contrast to other platforms where they are mapped to a specific
linker option by the compiler. This difference is a result of the greater
variety of ELF linkers and the fact that ELF linkers tend to handle libraries in
a more complicated fashion than on other platforms. This forces us to defer
handling the specifiers to the linker.

In order to achieve a level of source code compatibility with other platforms
we have restricted this feature to work with libraries that meet the following
"reasonable" requirements:

1. There are no competing defined symbols in a given set of libraries, or
   if they exist, the program owner doesn't care which is linked to their
   program.
2. There may be circular dependencies between libraries.

The binary representation is a mergeable string section (SHF_MERGE,
SHF_STRINGS), called .deplibs, with custom type SHT_LLVM_DEPENDENT_LIBRARIES
(0x6fff4c04). The compiler forms this section by concatenating the arguments of
the "comment lib" pragmas and --dependent-library options in the order they are
encountered. Partial (-r, -Ur) links are handled by concatenating .deplibs
sections with the normal mergeable string section rules. As an example, #pragma
comment(lib, "foo") would result in:

.section ".deplibs","MS",@llvm_dependent_libraries,1
         .asciz "foo"

For LTO, equivalent information to the contents of a the .deplibs section can be
retrieved by the LLD for bitcode input files.

LLD processes the dependent library specifiers in the following way:

1. Dependent libraries which are found from the specifiers in .deplibs sections
   of relocatable object files are added when the linker decides to include that
   file (which could itself be in a library) in the link. Dependent libraries
   behave as if they were appended to the command line after all other options. As
   a consequence the set of dependent libraries are searched last to resolve
   symbols.
2. It is an error if a file cannot be found for a given specifier.
3. Any command line options in effect at the end of the command line parsing apply
   to the dependent libraries, e.g. --whole-archive.
4. The linker tries to add a library or relocatable object file from each of the
   strings in a .deplibs section by; first, handling the string as if it was
   specified on the command line; second, by looking for the string in each of the
   library search paths in turn; third, by looking for a lib<string>.a or
   lib<string>.so (depending on the current mode of the linker) in each of the
   library search paths.
5. A new command line option --no-dependent-libraries tells LLD to ignore the
   dependent libraries.

Rationale for the above points:

1. Adding the dependent libraries last makes the process simple to understand
   from a developers perspective. All linkers are able to implement this scheme.
2. Error-ing for libraries that are not found seems like better behavior than
   failing the link during symbol resolution.
3. It seems useful for the user to be able to apply command line options which
   will affect all of the dependent libraries. There is a potential problem of
   surprise for developers, who might not realize that these options would apply
   to these "invisible" input files; however, despite the potential for surprise,
   this is easy for developers to reason about and gives developers the control
   that they may require.
4. This algorithm takes into account all of the different ways that ELF linkers
   find input files. The different search methods are tried by the linker in most
   obvious to least obvious order.
5. I considered adding finer grained control over which dependent libraries were
   ignored (e.g. MSVC has /nodefaultlib:<library>); however, I concluded that this
   is not necessary: if finer control is required developers can fall back to using
   the command line directly.

RFC thread: http://lists.llvm.org/pipermail/llvm-dev/2019-March/131004.html.

Differential Revision: https://reviews.llvm.org/D60274

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@360984 91177308-0d34-0410-b5e6-96231b3b80d8
2019-05-17 03:44:15 +00:00
Fangrui Song fceaf762c0 [llvm-readobj] Change -t to --symbols in tests. NFC
-t is --symbols in llvm-readobj but --section-details (unimplemented) in readelf.
The confusing option should not be used since we aim for improving
compatibility.

Keep just one llvm-readobj -t use case in test/tools/llvm-readobj/symbols.test

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@359661 91177308-0d34-0410-b5e6-96231b3b80d8
2019-05-01 09:28:24 +00:00
Fangrui Song 89bcca25b4 [llvm-nm][llvm-readelf] Avoid single-dash -long-option in tests
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@359383 91177308-0d34-0410-b5e6-96231b3b80d8
2019-04-27 16:12:14 +00:00
Steven Wu 65881148e9 Revert [ThinLTO] Fix ThinLTOCodegenerator to export llvm.used symbols
This reverts r357931 (git commit 8b70a5c11e08116955a875b9085433f14737bcaf)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@357932 91177308-0d34-0410-b5e6-96231b3b80d8
2019-04-08 18:53:21 +00:00
Steven Wu 13456d67c9 [ThinLTO] Fix ThinLTOCodegenerator to export llvm.used symbols
Summary:
ThinLTOCodeGenerator currently does not preserve llvm.used symbols and
it can internalize them. In order to pass the necessary information to the
legacy ThinLTOCodeGenerator, the input to the code generator is
rewritten to be based on lto::InputFile.

This fixes: PR41236
rdar://problem/49293439

Reviewers: tejohnson, pcc, dexonsmith

Reviewed By: tejohnson

Subscribers: mehdi_amini, inglorion, eraman, hiraditya, jkorous, dang, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60226

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@357931 91177308-0d34-0410-b5e6-96231b3b80d8
2019-04-08 18:24:10 +00:00
Rafael Auler e43e4afb37 [Linker] Fix crash handling appending linkage
Summary:
When linking two llvm.used arrays, if the resulting merged
array ends up with duplicated elements (with the same name) but with
different types, the IRLinker was crashing. This was supposed to be
legal, as the IRLinker bitcasts elements to match types in these
situations.

This bug was exposed by D56928 in clang to support attribute used
in member functions of class templates. Crash happened when self-hosting
with LTO. Since LLVM depends on attribute used to generate code
for the dump() method, ubiquitous in the code base, many input bc
had a definition of this method referenced in their llvm.used array.
Some of these classes got optimized, changing the type of the first
parameter (this) in the dump method, leading to a scenario with a
pool of valid definitions but some with a different type, triggering
this bug.

This is a memory bug: ValueMapper depends on (calls) the materializer
provided by IRLinker, and this materializer was freely calling RAUW
methods whenever a global definition was updated in the temporary merged
output file. However, replaceAllUsesWith may or may not destroy
constants that use this global. If the linked definition has a type
mismatch regarding the new def and the old def, the materializer would
bitcast the old type to the new type and the elements of the llvm.used
array, which already uses bitcast to i8*, would end up with elements
cascading two bitcasts. RAUW would then indirectly call the
constantfolder to update the constant to the new ref, which would,
instead of updating the constant, destroy it to be able to create
a new constant that folds the two bitcasts into one. The problem is that
ValueMapper works with pointers to the same constants that may be
getting destroyed by RAUW. Obviously, RAUW can update references in the
Module to do not use the old destroyed constant, but it can't update
ValueMapper's internal pointers to these constants, which are now
invalid.

The approach here is to move the task of RAUWing old definitions
outside of the materializer.

Test Plan:
Added LIT test case, tested clang self-hosting with D56928 and
verified it works

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D59552

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356597 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-20 19:20:07 +00:00
Robert Lougher d1ec87fb2f Resubmit r356511 "[TailCallElim] Add tailcall elimination pass to LTO pipelines"
Failing LLD tests have been fixed in r356593.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356594 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-20 19:08:18 +00:00
Robert Lougher 6364ead02b Revert r356511 "[TailCallElim] Add tailcall elimination pass to LTO pipelines"
Due to buildbot failures (LLD tests).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356516 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-19 20:54:20 +00:00
Robert Lougher e9a0d4ae07 [TailCallElim] Add tailcall elimination pass to LTO pipelines
LTO provides additional opportunities for tailcall elimination due to
link-time inlining and visibility of nocapture attribute. Testing showed
negligible impact on compilation times.

Differential Revision: https://reviews.llvm.org/D58391



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356511 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-19 20:24:28 +00:00
Francis Visoiu Mistrih 1e252811d6 Reland "[Remarks] Add -foptimization-record-passes to filter remark emission"
Currently we have -Rpass for filtering the remarks that are displayed as
diagnostics, but when using -fsave-optimization-record, there is no way
to filter the remarks while generating them.

This adds support for filtering remarks by passes using a regex.
Ex: `clang -fsave-optimization-record -foptimization-record-passes=inline`

will only emit the remarks coming from the pass `inline`.

This adds:

* `-fsave-optimization-record` to the driver
* `-opt-record-passes` to cc1
* `-lto-pass-remarks-filter` to the LTOCodeGenerator
* `--opt-remarks-passes` to lld
* `-pass-remarks-filter` to llc, opt, llvm-lto, llvm-lto2
* `-opt-remarks-passes` to gold-plugin

Differential Revision: https://reviews.llvm.org/D59268

Original llvm-svn: 355964

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@355984 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-12 21:22:27 +00:00
Matt Arsenault 6e8fb99b69 IR: Add immarg attribute
This indicates an intrinsic parameter is required to be a constant,
and should not be replaced with a non-constant value.

Add the attribute to all AMDGPU and generic intrinsics that comments
indicate it should apply to. I scanned other target intrinsics, but I
don't see any obvious comments indicating which arguments are intended
to be only immediates.

This breaks one questionable testcase for the autoupgrade. I'm unclear
on whether the autoupgrade is supposed to really handle declarations
which were never valid. The verifier fails because the attributes now
refer to a parameter past the end of the argument list.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@355981 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-12 21:02:54 +00:00
Francis Visoiu Mistrih a826459b5e Revert "[Remarks] Add -foptimization-record-passes to filter remark emission"
This reverts commit 20fff32b7d1f1a1bd417b22aa9f26ededd97a3e5.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@355976 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-12 20:54:18 +00:00
Francis Visoiu Mistrih 1bd774409d [Remarks] Add -foptimization-record-passes to filter remark emission
Currently we have -Rpass for filtering the remarks that are displayed as
diagnostics, but when using -fsave-optimization-record, there is no way
to filter the remarks while generating them.

This adds support for filtering remarks by passes using a regex.
Ex: `clang -fsave-optimization-record -foptimization-record-passes=inline`

will only emit the remarks coming from the pass `inline`.

This adds:

* `-fsave-optimization-record` to the driver
* `-opt-record-passes` to cc1
* `-lto-pass-remarks-filter` to the LTOCodeGenerator
* `--opt-remarks-passes` to lld
* `-pass-remarks-filter` to llc, opt, llvm-lto, llvm-lto2
* `-opt-remarks-passes` to gold-plugin

Differential Revision: https://reviews.llvm.org/D59268

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@355964 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-12 20:28:50 +00:00
Teresa Johnson e39377580b [LTO] Record whether LTOUnit splitting is enabled in index
Summary:
Records in the module summary index whether the bitcode was compiled
with the option necessary to enable splitting the LTO unit
(e.g. -fsanitize=cfi, -fwhole-program-vtables, or -fsplit-lto-unit).

The information is passed down to the ModuleSummaryIndex builder via a
new module flag "EnableSplitLTOUnit", which is propagated onto a flag
on the summary index.

This is then used during the LTO link to check whether all linked
summaries were built with the same value of this flag. If not, an error
is issued when we detect a situation requiring whole program visibility
of the class hierarchy. This is the case when both of the following
conditions are met:
1) We are performing LowerTypeTests or Whole Program Devirtualization.
2) There are type tests or type checked loads in the code.

Note I have also changed the ThinLTOBitcodeWriter to also gate the
module splitting on the value of this flag.

Reviewers: pcc

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

Differential Revision: https://reviews.llvm.org/D53890

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@350948 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-11 18:31:57 +00:00
Matthew Voss dc8dd58c4c [ThinLTO] Remove dllimport attribute from locally defined symbols
Summary:
The LTO/ThinLTO driver currently creates invalid bitcode by setting 
symbols marked dllimport as dso_local. The compiler often has access 
to the definition (often dllexport) and the declaration (often 
dllimport) of an object at link-time, leading to a conflicting 
declaration. This patch resolves the inconsistency by removing the
dllimport attribute.

Reviewers: tejohnson, pcc, rnk, echristo

Reviewed By: rnk

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

Differential Revision: https://reviews.llvm.org/D55627

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@349667 91177308-0d34-0410-b5e6-96231b3b80d8
2018-12-19 19:07:45 +00:00
Peter Collingbourne 2e4508a5ad LTO: Don't internalize available_externally globals.
This breaks C and C++ semantics because it can cause the address
of the global inside the module to differ from the address outside
of the module.

Differential Revision: https://reviews.llvm.org/D55237

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@348321 91177308-0d34-0410-b5e6-96231b3b80d8
2018-12-05 00:09:36 +00:00
Xin Tong eb1caa79c6 [LTO] Load sample profile in LTO link step.
Summary:
Load sample profile in LTO link step.
ThinLTO calls populateModulePassManager to load the profile

Reviewers: tejohnson, davidxl, danielcdh

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

Differential Revision: https://reviews.llvm.org/D54564

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@346971 91177308-0d34-0410-b5e6-96231b3b80d8
2018-11-15 18:06:42 +00:00
Pirama Arumuga Nainar 32530669f1 [LTO] Drop non-prevailing definitions only if linkage is not local or appending
Summary:
This fixes PR 37422

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

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

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

Reviewers: tejohnson, pcc

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

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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@346436 91177308-0d34-0410-b5e6-96231b3b80d8
2018-11-08 20:10:07 +00:00
Xin Tong fbe10782a9 [ThinLTO] Add an option to disable (thin)lto internalization.
Summary:
LTO and ThinLTO optimizes the IR differently.

One source of differences is the amount of internalizations that
can happen.

Add an option to enable/disable internalization so that other
differences can be studied in isolation. e.g. inlining.

There are other things lto and thinlto do differently, I will add
flags to enable/disable them as needed.

Reviewers: tejohnson, pcc, steven_wu

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

Differential Revision: https://reviews.llvm.org/D53294

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@346140 91177308-0d34-0410-b5e6-96231b3b80d8
2018-11-05 15:49:46 +00:00
Warren Ristow 43adb6744a Update test of r344198 to work with release builds.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@344286 91177308-0d34-0410-b5e6-96231b3b80d8
2018-10-11 20:19:25 +00:00
Warren Ristow 7f7ab9f57f [LTO] Account for overriding lib calls via the alias attribute
Given a library call that is represented as an llvm intrinsic call, but
later transformed to an actual call, if an overriding definition of that
library routine is provided indirectly via an alias, prevent LTO from
eliminating the definition.

This is a fix for PR38547.

Differential Revision: https://reviews.llvm.org/D52836


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@344198 91177308-0d34-0410-b5e6-96231b3b80d8
2018-10-10 22:54:31 +00:00
Xin Tong 773ad8be84 [ThinLTO] Keep non-prevailing (linkonce|weak)_odr symbols live
Summary:
If we have a symbol with (linkonce|weak)_odr linkage, we do not want
to dead strip it even it is not prevailing.

IR level (linkonce|weak)_odr symbol can become non-prevailing when we mix
ELF objects and IR objects where the (linkonce|weak)_odr symbol in the ELF
object is prevailing and the ones in the IR objects are not. Stripping
them will prevent us from doing optimizations with them.

By not dead stripping them, We will convert these symbols to
available_externally linkage as a result of non-prevailing and eventually
dropping them after inlining.

I modified cache-prevailing.ll to use linkonce linkage as it is
testing whether cache prevailing bit is effective or not, not
we should treat linkonce_odr alive or not

Reviewers: tejohnson, pcc

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

Differential Revision: https://reviews.llvm.org/D52893

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@343970 91177308-0d34-0410-b5e6-96231b3b80d8
2018-10-08 15:12:48 +00:00
Caroline Tice a53c520ec5 Pass code-model through Module IR to LTO which will use it.
Currently the code-model does not get saved in the module IR,
so if a code model is specified when compiling with LTO,
it gets lost and is not propagated properly to LTO. This patch,
along with one for the front end, fixes that.

Differential Revision: https://reviews.llvm.org/D52322



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@342760 91177308-0d34-0410-b5e6-96231b3b80d8
2018-09-21 18:41:31 +00:00
David Bolvansky 88ab670557 Enrich inline messages
Summary:
This patch improves Inliner to provide causes/reasons for negative inline decisions.
1. It adds one new message field to InlineCost to report causes for Always and Never instances. All Never and Always instantiations must provide a simple message.
2. Several functions that used to return the inlining results as boolean are changed to return InlineResult which carries the cause for negative decision.
3. Changed remark priniting and debug output messages to provide the additional messages and related inline cost.
4. Adjusted tests for changed printing.

Patch by: yrouban (Yevgeny Rouban)


Reviewers: craig.topper, sammccall, sgraenitz, NutshellySima, shchenz, chandlerc, apilipenko, javed.absar, tejohnson, dblaikie, sanjoy, eraman, xbolva00

Reviewed By: tejohnson, xbolva00

Subscribers: xbolva00, llvm-commits, arsenm, mehdi_amini, eraman, haicheng, steven_wu, dexonsmith

Differential Revision: https://reviews.llvm.org/D49412

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@338969 91177308-0d34-0410-b5e6-96231b3b80d8
2018-08-05 14:53:08 +00:00
David Bolvansky 8e70a95cbc Revert "Enrich inline messages", tests fail
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@338496 91177308-0d34-0410-b5e6-96231b3b80d8
2018-08-01 08:02:40 +00:00
David Bolvansky 788bdbbd5c Enrich inline messages
Summary:
This patch improves Inliner to provide causes/reasons for negative inline decisions.
1. It adds one new message field to InlineCost to report causes for Always and Never instances. All Never and Always instantiations must provide a simple message.
2. Several functions that used to return the inlining results as boolean are changed to return InlineResult which carries the cause for negative decision.
3. Changed remark priniting and debug output messages to provide the additional messages and related inline cost.
4. Adjusted tests for changed printing.

Patch by: yrouban (Yevgeny Rouban)


Reviewers: craig.topper, sammccall, sgraenitz, NutshellySima, shchenz, chandlerc, apilipenko, javed.absar, tejohnson, dblaikie, sanjoy, eraman, xbolva00

Reviewed By: tejohnson, xbolva00

Subscribers: xbolva00, llvm-commits, arsenm, mehdi_amini, eraman, haicheng, steven_wu, dexonsmith

Differential Revision: https://reviews.llvm.org/D49412

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@338494 91177308-0d34-0410-b5e6-96231b3b80d8
2018-08-01 07:37:16 +00:00
David Bolvansky 757fc2f38e Revert Enrich inline messages
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@338389 91177308-0d34-0410-b5e6-96231b3b80d8
2018-07-31 14:47:22 +00:00
David Bolvansky 99862d39d7 Enrich inline messages
Summary:
This patch improves Inliner to provide causes/reasons for negative inline decisions.
1. It adds one new message field to InlineCost to report causes for Always and Never instances. All Never and Always instantiations must provide a simple message.
2. Several functions that used to return the inlining results as boolean are changed to return InlineResult which carries the cause for negative decision.
3. Changed remark priniting and debug output messages to provide the additional messages and related inline cost.
4. Adjusted tests for changed printing.

Patch by: yrouban (Yevgeny Rouban)


Reviewers: craig.topper, sammccall, sgraenitz, NutshellySima, shchenz, chandlerc, apilipenko, javed.absar, tejohnson, dblaikie, sanjoy, eraman, xbolva00

Reviewed By: tejohnson, xbolva00

Subscribers: xbolva00, llvm-commits, arsenm, mehdi_amini, eraman, haicheng, steven_wu, dexonsmith

Differential Revision: https://reviews.llvm.org/D49412

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@338387 91177308-0d34-0410-b5e6-96231b3b80d8
2018-07-31 14:25:24 +00:00
Bob Haarman 10a832fe97 [LTO] Don't internalize declarations
Summary:
Some links were failing with "Global is external, but doesn't have
external or weak linkage!" in ThinLTO builds with debug
information. This happened when we elide the body of a global that is
referenced by debug info. This results in a declaration, which we
would then internalize - but declarations cannot be internal. This
change avoids the problem by not internalizing these declarations.

Fixes PR38046.

Reviewers: pcc, tejohnson

Subscribers: mehdi_amini, aprantl, hiraditya, JDevlieghere, steven_wu, dexonsmith, llvm-commits

Differential Revision: https://reviews.llvm.org/D49777

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@338100 91177308-0d34-0410-b5e6-96231b3b80d8
2018-07-27 05:40:29 +00:00
Teresa Johnson 073f01b8db [LTO] Handle __imp_ (dllimport) symbols consistently with lld
Summary:
Similar to what lld already does for dllimport symbols which are
prefaced with __imp_ (see lld patch r240620), strip off the __imp_
prefix in LTO. Otherwise we can get 2 separate GlobalResolution for
a single symbol, the dllimport declaration, and the definition, which
leads to incorrect LTO handling.

Fixes PR38105.

Reviewers: pcc

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

Differential Revision: https://reviews.llvm.org/D49138

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@337762 91177308-0d34-0410-b5e6-96231b3b80d8
2018-07-23 22:33:57 +00:00
Teresa Johnson 2f14f1125a [ThinLTO] Ensure the TargetLibraryInfo is constructed early enough
Summary:
Without this change, the WholeProgramDevirt pass, which requires the
TargetLibraryInfo, will construct one from the default triple.

Fixes PR38139.

Reviewers: pcc

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

Differential Revision: https://reviews.llvm.org/D49278

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@337750 91177308-0d34-0410-b5e6-96231b3b80d8
2018-07-23 21:58:19 +00:00
Eli Friedman 5119a48bec [LTO] Fix linking with an alias defined using another alias.
When we're linking an alias which will be defined later, we neeed to
build a GlobalAlias, or else we'll crash later in
IRLinker::linkGlobalValueBody.

clang sometimes constructs aliases like this for C++ destructors.

Differential Revision: https://reviews.llvm.org/D49316



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@337053 91177308-0d34-0410-b5e6-96231b3b80d8
2018-07-13 21:58:55 +00:00
Vlad Tsyrklevich 7dc602e516 [LowerTypeTests] Limit when icall jumptable entries are emitted
Summary:
Currently LowerTypeTests emits jumptable entries for all live external
and address-taken functions; however, we could limit the number of
functions that we emit entries for significantly.

For Cross-DSO CFI, we continue to emit jumptable entries for all
exported definitions.  In the non-Cross-DSO CFI case, we only need to
emit jumptable entries for live functions that are address-taken in live
functions. This ignores exported functions and functions that are only
address taken in dead functions. This change uses ThinLTO summary data
(now emitted for all modules during ThinLTO builds) to determine
address-taken and liveness info.

The logic for emitting jumptable entries is more conservative in the
regular LTO case because we don't have summary data in the case of
monolithic LTO builds; however, once summaries are emitted for all LTO
builds we can unify the Thin/monolithic LTO logic to only use summaries
to determine the liveness of address taking functions.

This change is a partial fix for PR37474. It reduces the build size for
nacl_helper by ~2-3%, the reduction is due to nacl_helper compiling in
lots of unused code and unused functions that are address taken in dead
functions no longer being being considered live due to emitted jumptable
references. The reduction for chromium is ~0.1-0.2%.

Reviewers: pcc, eugenis, javed.absar

Reviewed By: pcc

Subscribers: aheejin, dexonsmith, dschuff, mehdi_amini, eraman, steven_wu, llvm-commits, kcc

Differential Revision: https://reviews.llvm.org/D47652

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@337038 91177308-0d34-0410-b5e6-96231b3b80d8
2018-07-13 19:57:39 +00:00
Teresa Johnson 633b851c9a [ThinLTO] Add per-module indexes to combined index consistently
Summary:
Without this change we only add module paths to the combined index when
there is a module hash or at least one global value. Make this more
consistent by adding the module to the index whenever there is a summary
section, and it is a per-module summary (had a MODULE_CODE_SOURCE_FILENAME
record).

Since we will no longer add module paths lazily, add a new interface to get
the module info from the index that asserts it is already added.

Fixes PR37899.

Reviewers: Vlad, pcc

Subscribers: mehdi_amini, inglorion, steven_wu, llvm-commits

Differential Revision: https://reviews.llvm.org/D48511

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335567 91177308-0d34-0410-b5e6-96231b3b80d8
2018-06-26 01:32:58 +00:00
Vlad Tsyrklevich 444617b4b3 IRMover: Account for matching types present across modules
Summary:
Due to uniqueing of DICompositeTypes, it's possible for a type from one
module to be loaded into another earlier module without being renamed.
Then when the defining module is being IRMoved, the type can be used as
a Mapping destination before being loaded, such that when it's requested
using TypeMapTy::get() it will fail with an assertion that the type is a
source type when it's actually a type in both the source and
destination modules. Correctly handle that case by allowing a non-opaque
non-literal struct type be present in both modules.

Fix for PR37684.

Reviewers: pcc, tejohnson

Reviewed By: pcc, tejohnson

Subscribers: tobiasvk, mehdi_amini, steven_wu, llvm-commits, kcc

Differential Revision: https://reviews.llvm.org/D47898

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335145 91177308-0d34-0410-b5e6-96231b3b80d8
2018-06-20 16:50:56 +00:00
Shiva Chen a8a13bc662 [DebugInfo] Add DILabel metadata and intrinsic llvm.dbg.label.
In order to set breakpoints on labels and list source code around
labels, we need collect debug information for labels, i.e., label
name, the function label belong, line number in the file, and the
address label located. In order to keep these information in LLVM
IR and to allow backend to generate debug information correctly.
We create a new kind of metadata for labels, DILabel. The format
of DILabel is

!DILabel(scope: !1, name: "foo", file: !2, line: 3)

We hope to keep debug information as much as possible even the
code is optimized. So, we create a new kind of intrinsic for label
metadata to avoid the metadata is eliminated with basic block.
The intrinsic will keep existing if we keep it from optimized out.
The format of the intrinsic is

llvm.dbg.label(metadata !1)

It has only one argument, that is the DILabel metadata. The
intrinsic will follow the label immediately. Backend could get the
label metadata through the intrinsic's parameter.

We also create DIBuilder API for labels to be used by Frontend.
Frontend could use createLabel() to allocate DILabel objects, and use
insertLabel() to insert llvm.dbg.label intrinsic in LLVM IR.

Differential Revision: https://reviews.llvm.org/D45024

Patch by Hsiangkai Wang.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@331841 91177308-0d34-0410-b5e6-96231b3b80d8
2018-05-09 02:40:45 +00:00
Teresa Johnson 61d9a69a18 [LTO] Allow pass remarks with hotness to be set when emitting to stderr
Summary:
Set setDiagnosticsHotnessRequested before the early exit check for a
diagnostic output file, so that pass remarks with hotness works when
emitting pass remarks to stderr (e.g. via -pass-remarks=.).

Also fix the llvm-lto2 diagnistic handler so that it only calls exit(1)
when the diagnistic is an error type. Otherwise the new test invocation
of llvm-lto2 with -pass-remarks causes it to fail. The new code is
consistent with the diagnostic handler elsewhere (e.g. on the
LLVMContext).

Reviewers: pcc, davide

Subscribers: fhahn, mehdi_amini, llvm-commits, inglorion

Differential Revision: https://reviews.llvm.org/D46387

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@331569 91177308-0d34-0410-b5e6-96231b3b80d8
2018-05-04 23:59:34 +00:00
Teresa Johnson 3a0c276585 [ThinLTO] Add support for optimization remarks to thinBackend
Summary:
Support was added to the regular LTO backend, but not thinBackend.
This patch adds that support.

Reviewers: pcc, davide

Subscribers: mehdi_amini, inglorion, llvm-commits

Differential Revision: https://reviews.llvm.org/D46376

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@331481 91177308-0d34-0410-b5e6-96231b3b80d8
2018-05-03 20:24:12 +00:00
Vitaly Buka b6a38e0857 Object: Don't mark alias unconditionally defined
Summary:
Can't remove EmitAssignment override as llvm/test/Object/X86/nm-bitcodeweak.test
expects this behavior.

Reviewers: pcc, espindola

Subscribers: mehdi_amini, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D44596

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@329651 91177308-0d34-0410-b5e6-96231b3b80d8
2018-04-10 00:53:16 +00:00
Vitaly Buka 488250e1ef Object: Fix handling of @@@ in .symver directive
Summary:
name@@@nodename is going to be replaced with name@@nodename if symbols is
defined in the assembled file, or name@nodename if undefined.
https://sourceware.org/binutils/docs/as/Symver.html

Fixes PR36623

Reviewers: pcc, espindola

Subscribers: mehdi_amini, hiraditya

Differential Revision: https://reviews.llvm.org/D44274

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@327930 91177308-0d34-0410-b5e6-96231b3b80d8
2018-03-20 00:45:03 +00:00
Bob Haarman 17f0b88177 Revert "[LTO] Support filtering by hotness threshold"
This reverts commit 1f3bd185c53beb6aa68446974b7e80837abd6ef0 (r326107)
because it fails
ThinLTO/X86/diagnostic-handler-remarks-with-hotness.ll.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@326975 91177308-0d34-0410-b5e6-96231b3b80d8
2018-03-08 01:13:10 +00:00
Adam Nemet cc03b6aaf8 [LTO] Support filtering by hotness threshold
This wires up -pass-remarks-hotness-threshold to LTO and ThinLTO.

Next is to change the clang driver to pass this
with -fdiagnostics-hotness-threshold.

Differential Revision: https://reviews.llvm.org/D41465

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@326107 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-26 18:37:45 +00:00
Peter Collingbourne 3940160b8f LTO: Include live bit in ThinLTO cache key.
As of r323633, this bit started controlling whether symbol definitions
appear in object files, and it also became sensitive to the prevailing
bit, so it needs to be included in the key.

Differential Revision: https://reviews.llvm.org/D43109

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@324711 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-09 05:58:55 +00:00
Peter Collingbourne 36db710926 LTO: Also include dso-local bit for calls in ThinLTO cache key.
Differential Revision: https://reviews.llvm.org/D42934

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@324291 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-05 23:46:32 +00:00
Peter Collingbourne 2e9c44b034 LTO: Include dso-local bit in ThinLTO cache key.
Differential Revision: https://reviews.llvm.org/D42713

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@324253 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-05 17:17:51 +00:00
Teresa Johnson b46c3d9efb [ThinLTO] Convert dead alias to declarations
Summary:
This complements the fixes in r323633 and r324075 which drop the
definitions of dead functions and variables, respectively.

Fixes PR36208.

Reviewers: grimar, rafael

Subscribers: mehdi_amini, llvm-commits, inglorion

Differential Revision: https://reviews.llvm.org/D42856

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@324242 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-05 15:44:27 +00:00
George Rimar 89df749abf [ThinLTO] - Fix for "ThinLTO inlines variables that should be discarded".
This fixes PR36187.

Patch teaches ThinLTO to drop non-prevailing variables, 
just like we recently did for functions (in r323633).

Differential revision: https://reviews.llvm.org/D42798

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@324075 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-02 12:17:33 +00:00
Peter Collingbourne b359cf72b9 LTO: Drop comdats when converting definitions to declarations.
Differential Revision: https://reviews.llvm.org/D42715

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@323844 91177308-0d34-0410-b5e6-96231b3b80d8
2018-01-31 02:51:03 +00:00