Commit Graph

28 Commits

Author SHA1 Message Date
Benjamin Kramer 5b2a7348b7 [IRTests] With opaque ptrs we can test that there is no bitcast inserted 2022-06-02 09:56:11 +02:00
Nikita Popov 41d5033eb1 [IR] Enable opaque pointers by default
This enabled opaque pointers by default in LLVM. The effect of this
is twofold:

* If IR that contains *neither* explicit ptr nor %T* types is passed
  to tools, we will now use opaque pointer mode, unless
  -opaque-pointers=0 has been explicitly passed.
* Users of LLVM as a library will now default to opaque pointers.
  It is possible to opt-out by calling setOpaquePointers(false) on
  LLVMContext.

A cmake option to toggle this default will not be provided. Frontends
or other tools that want to (temporarily) keep using typed pointers
should disable opaque pointers via LLVMContext.

Differential Revision: https://reviews.llvm.org/D126689
2022-06-02 09:40:56 +02:00
Arthur Eubanks 05392466f0 Reland [IR] Increase max alignment to 4GB
Currently the max alignment representable is 1GB, see D108661.
Setting the align of an object to 4GB is desirable in some cases to make sure the lower 32 bits are clear which can be used for some optimizations, e.g. https://crbug.com/1016945.

This uses an extra bit in instructions that carry an alignment. We can store 15 bits of "free" information, and with this change some instructions (e.g. AtomicCmpXchgInst) use 14 bits.
We can increase the max alignment representable above 4GB (up to 2^62) since we're only using 33 of the 64 values, but I've just limited it to 4GB for now.

The one place we have to update the bitcode format is for the alloca instruction. It stores its alignment into 5 bits of a 32 bit bitfield. I've added another field which is 8 bits and should be future proof for a while. For backward compatibility, we check if the old field has a value and use that, otherwise use the new field.

Updating clang's max allowed alignment will come in a future patch.

Reviewed By: hans

Differential Revision: https://reviews.llvm.org/D110451
2021-10-06 13:29:23 -07:00
Arthur Eubanks 569346f274 Revert "Reland [IR] Increase max alignment to 4GB"
This reverts commit 8d64314ffe.
2021-10-06 11:38:11 -07:00
Arthur Eubanks 8d64314ffe Reland [IR] Increase max alignment to 4GB
Currently the max alignment representable is 1GB, see D108661.
Setting the align of an object to 4GB is desirable in some cases to make sure the lower 32 bits are clear which can be used for some optimizations, e.g. https://crbug.com/1016945.

This uses an extra bit in instructions that carry an alignment. We can store 15 bits of "free" information, and with this change some instructions (e.g. AtomicCmpXchgInst) use 14 bits.
We can increase the max alignment representable above 4GB (up to 2^62) since we're only using 33 of the 64 values, but I've just limited it to 4GB for now.

The one place we have to update the bitcode format is for the alloca instruction. It stores its alignment into 5 bits of a 32 bit bitfield. I've added another field which is 8 bits and should be future proof for a while. For backward compatibility, we check if the old field has a value and use that, otherwise use the new field.

Updating clang's max allowed alignment will come in a future patch.

Reviewed By: hans

Differential Revision: https://reviews.llvm.org/D110451
2021-10-06 11:03:51 -07:00
Arthur Eubanks 72cf8b6044 Revert "[IR] Increase max alignment to 4GB"
This reverts commit df84c1fe78.

Breaks some bots
2021-10-06 10:21:35 -07:00
Arthur Eubanks df84c1fe78 [IR] Increase max alignment to 4GB
Currently the max alignment representable is 1GB, see D108661.
Setting the align of an object to 4GB is desirable in some cases to make sure the lower 32 bits are clear which can be used for some optimizations, e.g. https://crbug.com/1016945.

This uses an extra bit in instructions that carry an alignment. We can store 15 bits of "free" information, and with this change some instructions (e.g. AtomicCmpXchgInst) use 14 bits.
We can increase the max alignment representable above 4GB (up to 2^62) since we're only using 33 of the 64 values, but I've just limited it to 4GB for now.

The one place we have to update the bitcode format is for the alloca instruction. It stores its alignment into 5 bits of a 32 bit bitfield. I've added another field which is 8 bits and should be future proof for a while. For backward compatibility, we check if the old field has a value and use that, otherwise use the new field.

Updating clang's max allowed alignment will come in a future patch.

Reviewed By: hans

Differential Revision: https://reviews.llvm.org/D110451
2021-10-06 09:54:14 -07:00
Roman Lebedev 564d85e090
The maximal representable alignment in LLVM IR is 1GiB, not 512MiB
In LLVM IR, `AlignmentBitfieldElementT` is 5-bit wide
But that means that the maximal alignment exponent is `(1<<5)-2`,
which is `30`, not `29`. And indeed, alignment of `1073741824`
roundtrips IR serialization-deserialization.

While this doesn't seem all that important, this doubles
the maximal supported alignment from 512MiB to 1GiB,
and there's actually one noticeable use-case for that;
On X86, the huge pages can have sizes of 2MiB and 1GiB (!).

So while this doesn't add support for truly huge alignments,
which i think we can easily-ish do if wanted, i think this adds
zero-cost support for a not-trivially-dismissable case.

I don't believe we need any upgrade infrastructure,
and since we don't explicitly record the IR version,
we don't need to bump one either.

As @craig.topper speculates in D108661#2963519,
this might be an artificial limit imposed by the original implementation
of the `getAlignment()` functions.

Differential Revision: https://reviews.llvm.org/D108661
2021-08-26 12:53:39 +03:00
OCHyams bbccdf6f81 [DebugInfo] Replace debug uses in replaceUsesOutsideBlock
Value::replaceUsesOutsideBlock doesn't replace debug uses which leads to an
unnecessary reduction in variable location coverage. Fix this, add a unittest for
it, and add a regression test demonstrating the change through instcombine's
replacedSelectWithOperand.

Reviewed By: djtodoro

Differential Revision: https://reviews.llvm.org/D99169
2021-04-19 11:06:53 +01:00
OCHyams 17cec07184 Revert "[DebugInfo] Replace debug uses in replaceUsesOutsideBlock"
This reverts commit 96a1e6b7cf.

Failing build bots e.g. https://lab.llvm.org/buildbot/#/builders/161/builds/163
2021-04-15 16:35:45 +01:00
OCHyams 96a1e6b7cf [DebugInfo] Replace debug uses in replaceUsesOutsideBlock
Value::replaceUsesOutsideBlock doesn't replace debug uses which leads to an
unnecessary reduction in variable location coverage. Fix this, add a unittest for
it, and add a regression test demonstrating the change through instcombine's
replacedSelectWithOperand.

Reviewed By: djtodoro

Differential Revision: https://reviews.llvm.org/D99169
2021-04-15 16:19:36 +01:00
Guillaume Chatelet 0e62011df8 [Alignment][NFC] Remove dependency on GlobalObject::setAlignment(unsigned)
Summary:
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

Reviewers: courbet

Subscribers: arsenm, mehdi_amini, jvesely, nhaehnle, hiraditya, steven_wu, dexonsmith, dang, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D68944

llvm-svn: 374880
2019-10-15 11:24:36 +00:00
Guillaume Chatelet 396521378f [LLVM][Alignment] Introduce Alignment In GlobalObject
Summary:
This is patch is part of a serie to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

Reviewers: jfb

Subscribers: hiraditya, dexonsmith, llvm-commits, courbet

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65748

Address comments

llvm-svn: 368000
2019-08-06 09:03:21 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Roman Tereshin d96de6f6ae [MIR] Making MIR Printing, opt -dot-cfg, and -debug printing faster
Value::printAsOperand has been scanning the entire module just to
print a single value as an operand, regardless being asked to print a
type or not at all, and regardless really needing to scan the module
to print a type.

It made some of the users of the method exceptionally slow on large
IR-modules (or large MIR-files with large IR-modules embedded).

This patch defers scanning a module looking for struct types, mostly
numbered struct types, as much as possible, speeding up those users
w/o changing any APIs at all.

See speedup examples below:

Release Build:

# 83 seconds -> 5.5 seconds
time ./bin/llc -start-before=irtranslator -stop-after=irtranslator \
  -global-isel -global-isel-abort=2 -simplify-mir sqlite3.O0.ll -o \
  sqlite3.O0.ll.regbankselected.mir

# 133 seconds -> 6.2 seconds
time ./bin/opt sqlite3.O0.ll -dot-cfg -disable-output

Release + Asserts Build:

# 95 seconds -> 5.5 seconds
time ./bin/llc -start-before=irtranslator -stop-after=irtranslator \
  -global-isel -global-isel-abort=2 -simplify-mir sqlite3.O0.ll -o \
  sqlite3.O0.ll.regbankselected.mir

# 146 seconds -> 6.2 seconds
time ./bin/opt sqlite3.O0.ll -dot-cfg -disable-output

# 1096 seconds -> 553 seconds
time ./bin/llc -debug-only=isel -fast-isel=false -stop-after=isel \
  sqlite3.O0.ll -o /dev/null 2> err

where sqlite3.O0.ll is non-optimized IR produced from
sqlite-amalgamation (http://sqlite.org/download.html), which is entire
SQLite3 implementation in a single C-file.

Benchmarked on 4-cores / 8 threads PCI-E SSD iMac running macOS

Reviewers: dexonsmith, bkramer, void, chandlerc, aditya_nandakumar, dsanders, qcolombet, 

Reviewed By: bogner

Subscribers: thegameg, llvm-commits

Differential Revision: https://reviews.llvm.org/D44132

llvm-svn: 328246
2018-03-22 21:29:07 +00:00
Chandler Carruth 9a67b07398 Re-sort #include lines for unittests. This uses a slightly modified
clang-format (https://reviews.llvm.org/D33932) to keep primary headers
at the top and handle new utility headers like 'gmock' consistently with
other utility headers.

No other change was made. I did no manual edits, all of this is
clang-format.

This should allow other changes to have more clear and focused diffs,
and is especially motivated by moving some headers into more focused
libraries.

llvm-svn: 304786
2017-06-06 11:06:56 +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
Mehdi Amini 03b42e41bf Remove every uses of getGlobalContext() in LLVM (but the C API)
At the same time, fixes InstructionsTest::CastInst unittest: yes
you can leave the IR in an invalid state and exit when you don't
destroy the context (like the global one), no longer now.

This is the first part of http://reviews.llvm.org/D19094

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266379
2016-04-14 21:59:01 +00:00
Duncan P. N. Exon Smith c8925b1871 unittests: Remove implicit ilist iterator conversions, NFC
llvm-svn: 250843
2015-10-20 18:30:20 +00:00
Alex Lorenz 991a6241d3 IR: Expose the method 'getLocalSlot' in the module slot tracker.
This commit publicly exposes the method 'getLocalSlot' in the
'ModuleSlotTracker' class.

This change is useful for MIR serialization, to serialize the unnamed basic
block and unnamed alloca references.

Reviewers: Duncan P. N. Exon Smith
llvm-svn: 243336
2015-07-27 22:31:04 +00:00
Duncan P. N. Exon Smith 1f8a99a9ae IR: Expose ModuleSlotTracker in Value::print()
Allow callers of `Value::print()` and `Metadata::print()` to pass in a
`ModuleSlotTracker`.  This allows them to pay only once for calculating
module-level slots (such as Metadata).

This is related to PR23865, where there was a huge cost for
`MachineFunction::print()`.  Although I don't have a *particular* user
in mind for this new code, I have hit big slowdowns before when running
`opt -debug`, and I think this will be useful.  Going forward, if
someone hits a big slowdown with `print()` statements, they can create a
`ModuleSlotTracker` and send it through.  Similarly, adding support to
`Value::dump()` and `Metadata::dump()` should be trivial.

I added unit tests to be sure the `print()` functions actually behave
the same way with and without the slot tracker.

llvm-svn: 240867
2015-06-27 00:38:26 +00:00
Rafael Espindola a492fe972d Add unittest for extreme alignments.
llvm-svn: 220483
2014-10-23 14:45:19 +00:00
Rafael Espindola 11c07d7eec Modernize the .ll parsing interface.
* Use StringRef instead of std::string&
* Return a std::unique_ptr<Module> instead of taking an optional module to write
  to (was not really used).
* Use current comment style.
* Use current naming convention.

llvm-svn: 215989
2014-08-19 16:58:54 +00:00
Craig Topper 66f09ad041 [C++11] Use 'nullptr'.
llvm-svn: 210442
2014-06-08 22:29:17 +00:00
Ahmed Charles 56440fd820 Replace OwningPtr<T> with std::unique_ptr<T>.
This compiles with no changes to clang/lld/lldb with MSVC and includes
overloads to various functions which are used by those projects and llvm
which have OwningPtr's as parameters. This should allow out of tree
projects some time to move. There are also no changes to libs/Target,
which should help out of tree targets have time to move, if necessary.

llvm-svn: 203083
2014-03-06 05:51:42 +00:00
Chandler Carruth 9aca918df9 Move the LLVM IR asm writer header files into the IR directory, as they
are part of the core IR library in order to support dumping and other
basic functionality.

Rename the 'Assembly' include directory to 'AsmParser' to match the
library name and the only functionality left their -- printing has been
in the core IR library for quite some time.

Update all of the #includes to match.

All of this started because I wanted to have the layering in good shape
before I started adding support for printing LLVM IR using the new pass
infrastructure, and commandline support for the new pass infrastructure.

llvm-svn: 198688
2014-01-07 12:34:26 +00:00
Matt Arsenault 27e783e90d Fix getOrInsertGlobal dropping the address space.
Currently it will insert an illegal bitcast.
Arguably, the address space argument should be
added for the creation case.

llvm-svn: 191702
2013-09-30 21:23:03 +00:00
Benjamin Kramer eee73f5fcf Fix a disconcerting bug in Value::isUsedInBasicBlock, which gave wrong answers for blocks larger than 3 instrs.
Also add a unit test. PR15727.

llvm-svn: 179370
2013-04-12 08:33:11 +00:00