Commit Graph

8210 Commits

Author SHA1 Message Date
Roman Lebedev fef0cf0810 [LangRef] Add integer min/max/abs intrinsics
Add LangRef specification for the llvm.abs, llvm.umin, llvm.umax,
llvm.smin, and llvm.smax integer intrinsics.

Link to RFC:
https://lists.llvm.org/pipermail/llvm-dev/2020-June/142257.html

Proposed alive2 implementation:
https://github.com/AliveToolkit/alive2/pull/353

Differential Revision: https://reviews.llvm.org/D81829
2020-07-23 20:56:18 +02:00
Craig Topper 68382d5852 [X86][docs] Add mention of removal of 'mpx' backend feature to the release notes.
I removed the feature from X86.td in ebe5f17f9c
2020-07-23 08:25:34 -07:00
Russell Gallop c798628fbd [docs] Fix TestSuiteGuide.md to mention scipy
This has been required since https://reviews.llvm.org/D57828.

Differential Revision: https://reviews.llvm.org/D82379
2020-07-23 14:21:59 +01:00
Louis Dionne afa1afd410 [CMake] Bump CMake minimum version to 3.13.4
This upgrade should be friction-less because we've already been ensuring
that CMake >= 3.13.4 is used.

This is part of the effort discussed on llvm-dev here:

  http://lists.llvm.org/pipermail/llvm-dev/2020-April/140578.html

Differential Revision: https://reviews.llvm.org/D78648
2020-07-22 14:25:07 -04:00
Sameer Arora 303a7f7a26 [llvm-libtool-darwin] Add support for -static option
Add support for creating static libraries when the input includes only
Mach-O binaries (and not libraries/archives themselves).

Reviewed by alexshap, Ktwu, smeenai, jhenderson, MaskRay, mtrent

Differential Revision: https://reviews.llvm.org/D83002
2020-07-21 13:08:49 -07:00
Chris Morin 28da5759bd Fix typo in tutorial 2020-07-21 17:28:24 +02:00
Yuanfang Chen 589c646a7e [llc] (almost) remove `--print-machineinstrs`
Its effect could be achieved by
`-stop-after`,`-print-after`,`-print-after-all`. But a few tests need to
print MIR after ISel which could not be done with
`-print-after`/`-stop-after` since isel pass does not have commandline name.
That's the reason `--print-machineinstrs` is downgraded to
`--print-after-isel` in this patch. `--print-after-isel` could be
removed after we switch to new pass manager since isel pass would have a
commandline text name to use `print-after` or equivalent switches.

The motivation of this patch is to reduce tests dependency on
would-be-deprecated feature.

Reviewed By: arsenm, dsanders

Differential Revision: https://reviews.llvm.org/D83275
2020-07-20 10:43:28 -07:00
Alok Kumar Sharma 2d10258a31 [DebugInfo] Support for DW_AT_associated and DW_AT_allocated.
Summary:
This support is needed for the Fortran array variables with pointer/allocatable
attribute. This support enables debugger to identify the status of variable
whether that is currently allocated/associated.

  for pointer array (before allocation/association)
  without DW_AT_associated

(gdb) pt ptr
type = integer (140737345375288:140737354129776)
(gdb) p ptr
value requires 35017956 bytes, which is more than max-value-size

  with DW_AT_associated

(gdb) pt ptr
type = integer (:)
(gdb) p ptr
$1 = <not associated>

  for allocatable array (before allocation)

  without DW_AT_allocated

(gdb) pt arr
type = integer (140737345375288:140737354129776)
(gdb) p arr
value requires 35017956 bytes, which is more than max-value-size

  with DW_AT_allocated

(gdb) pt arr
type = integer, allocatable (:)
(gdb) p arr
$1 = <not allocated>

    Testing
- unit test cases added
- check-llvm
- check-debuginfo

Reviewed By: aprantl

Differential Revision: https://reviews.llvm.org/D83544
2020-07-20 19:54:35 +05:30
Matt Arsenault 5e999cbe8d IR: Define byref parameter attribute
This allows tracking the in-memory type of a pointer argument to a
function for ABI purposes. This is essentially a stripped down version
of byval to remove some of the stack-copy implications in its
definition.

This includes the base IR changes, and some tests for places where it
should be treated similarly to byval. Codegen support will be in a
future patch.

My original attempt at solving some of these problems was to repurpose
byval with a different address space from the stack. However, it is
technically permitted for the callee to introduce a write to the
argument, although nothing does this in reality. There is also talk of
removing and replacing the byval attribute, so a new attribute would
need to take its place anyway.

This is intended avoid some optimization issues with the current
handling of aggregate arguments, as well as fixes inflexibilty in how
frontends can specify the kernel ABI. The most honest representation
of the amdgpu_kernel convention is to expose all kernel arguments as
loads from constant memory. Today, these are raw, SSA Argument values
and codegen is responsible for turning these into loads.

Background:

There currently isn't a satisfactory way to represent how arguments
for the amdgpu_kernel calling convention are passed. In reality,
arguments are passed in a single, flat, constant memory buffer
implicitly passed to the function. It is also illegal to call this
function in the IR, and this is only ever invoked by a driver of some
kind.

It does not make sense to have a stack passed parameter in this
context as is implied by byval. It is never valid to write to the
kernel arguments, as this would corrupt the inputs seen by other
dispatches of the kernel. These argumets are also not in the same
address space as the stack, so a copy is needed to an alloca. From a
source C-like language, the kernel parameters are invisible.
Semantically, a copy is always required from the constant argument
memory to a mutable variable.

The current clang calling convention lowering emits raw values,
including aggregates into the function argument list, since using
byval would not make sense. This has some unfortunate consequences for
the optimizer. In the aggregate case, we end up with an aggregate
store to alloca, which both SROA and instcombine turn into a store of
each aggregate field. The optimizer never pieces this back together to
see that this is really just a copy from constant memory, so we end up
stuck with expensive stack usage.

This also means the backend dictates the alignment of arguments, and
arbitrarily picks the LLVM IR ABI type alignment. By allowing an
explicit alignment, frontends can make better decisions. For example,
there's real no advantage to an aligment higher than 4, so a frontend
could choose to compact the argument layout. Similarly, there is a
high penalty to using an alignment lower than 4, so a frontend could
opt into more padding for small arguments.

Another design consideration is when it is appropriate to expose the
fact that these arguments are all really passed in adjacent
memory. Currently we have a late IR optimization pass in codegen to
rewrite the kernel argument values into explicit loads to enable
vectorization. In most programs, unrelated argument loads can be
merged together. However, exposing this property directly from the
frontend has some disadvantages. We still need a way to track the
original argument sizes and alignments to report to the driver. I find
using some side-channel, metadata mechanism to track this
unappealing. If the kernel arguments were exposed as a single buffer
to begin with, alias analysis would be unaware that the padding bits
betewen arguments are meaningless. Another family of problems is there
are still some gaps in replacing all of the available parameter
attributes with metadata equivalents once lowered to loads.

The immediate plan is to start using this new attribute to handle all
aggregate argumets for kernels. Long term, it makes sense to migrate
all kernel arguments, including scalars, to be passed indirectly in
the same manner.

Additional context is in D79744.
2020-07-20 10:23:09 -04:00
Elvina Yakubova df952cb914 [llvm-readobj] Print error when executed with no input files
This patch changes llvm-readelf (and llvm-readobj for consistency)
behavior to print an error when executed with no input files.

Reading from stdin can be achieved via a '-' for the input
object.

Fixes https://bugs.llvm.org/show_bug.cgi?id=46400

Differential Revision: https://reviews.llvm.org/D83704

Reviewed by: jhenderson, MaskRay, sbc, jyknight
2020-07-20 10:39:05 +01:00
Sameer Arora 6c43ed608d Introducing llvm-libtool-darwin
This diff starts the implementation of llvm-libtool-darwin
(an llvm based replacement of cctool's libtool).
Libtool is used for creating static and dynamic libraries
from a bunch of object files given as input.

Reviewed by alexshap, smeenai, jhenderson, MaskRay

Differential Revision: https://reviews.llvm.org/D82923
2020-07-17 08:07:02 -07:00
Clement Courbet 6bddd099ac Revert "[llvm-exegesis] Add benchmark latency option on X86 that uses LBR for more precise measurements."
From @erichkeane:
```
This patch doesn't seem to build for me:
/iusers/ekeane1/workspaces/llvm-project/llvm/tools/llvm-exegesis/lib/X86/X86Counter.cpp: In function ‘llvm::Error llvm::exegesis::parseDataBuffer(const char*, size_t, const void*, const void*, llvm::SmallVector<long int, 4>*)’:
/iusers/ekeane1/workspaces/llvm-project/llvm/tools/llvm-exegesis/lib/X86/X86Counter.cpp:99:37: error: ‘struct perf_branch_entry’ has no member named ‘cycles’

CycleArray->push_back(Entry.cycles);
I'm on RHEL7, so I have kernel 3.10, so it doesn't have 'cycles'.

According ot this: https://elixir.bootlin.com/linux/v4.3/source/include/uapi/linux/perf_event.h#L963 kernel 4.3 is the first time that 'cycles' appeared in this structure.
```
2020-07-17 16:55:17 +02:00
Juneyoung Lee fd1f8072a8 [LangRef] Mention that freeze does not consider aggregate's paddings
Make explicit that freeze does not touch paddings of an aggregate.
(Relevant comment: https://reviews.llvm.org/D83752#2152550)

This implies that `v = freeze(load p); store v, q` may still leave undef bits
or poison in memory if `v` is an aggregate, but it still happens for
non-byte integers such as i1.

Differential Revision: https://reviews.llvm.org/D83927
2020-07-17 11:53:26 +09:00
Matt Arsenault a2a3adcc66 Fix incorrect file path in documentation 2020-07-16 15:53:11 -04:00
Jinsong Ji 32d36d9edc [docs] fix ident in llvm-exegesis.rst 2020-07-16 17:30:09 +00:00
Jinsong Ji 971dd3f150 [docs][lldb] Fix lldb item in releasenotes
Reviewed By: JDevlieghere

Differential Revision: https://reviews.llvm.org/D83962
2020-07-16 17:07:53 +00:00
Vy Nguyen 1360e140cc [llvm-exegesis] Add benchmark latency option on X86 that uses LBR for more precise measurements.
Starting with Skylake, the LBR contains the precise number of cycles between the two
    consecutive branches.
    Making use of this will hopefully make the measurements more precise than the
    existing methods of using RDTSC.

            Differential Revision: https://reviews.llvm.org/D77422
2020-07-16 12:12:46 -04:00
Sjoerd Meijer 15d058f16e Follow up of 2b3c505d0f6e: fixed a typo, and added some more formatting. NFC. 2020-07-16 11:16:48 +01:00
Mehdi Amini 221979b691 Document the testing of Analyses in the LLVM testing guide (NFC)
This came up in a recent review, someone was wondering were was
this all documented and I couldn't find a reference to provide.

Differential Revision: https://reviews.llvm.org/D83816
2020-07-15 21:11:49 +00:00
Mehdi Amini 140c296ef5 Clarify a bit the guideline on omitting braces, including more examples (NFC)
Like most readability rules, it isn't absolute and there is a matter of taste
to it. I think more recent part of the project may be more consistent in the
current application of the guideline. I suspect sources like
mlir/lib/Dialect/StandardOps/IR/Ops.cpp may be examples of this at the moment.

Differential Revision: https://reviews.llvm.org/D82594
2020-07-15 21:11:30 +00:00
Hans Wennborg 7ab7b979d2 Bump the trunk major version to 12
and clear the release notes.
2020-07-15 12:05:05 +02:00
Tim Northover 5165b2b5fd AArch64+ARM: make LLVM consider system registers volatile.
Some of the system registers readable on AArch64 and ARM platforms
return different values with each read (for example a timer counter),
these shouldn't be hoisted outside loops or otherwise interfered with,
but the normal @llvm.read_register intrinsic is only considered to read
memory.

This introduces a separate @llvm.read_volatile_register intrinsic and
maps all system-registers on ARM platforms to use it for the
__builtin_arm_rsr calls. Registers declared with asm("r9") or similar
are unaffected.
2020-07-15 09:47:36 +01:00
Sjoerd Meijer 2b3c505d0f [Matrix] Intrinsic descriptions
This changes the matrix load/store intrinsic definitions to load/store from/to
a pointer, and not from/to a pointer to a vector, as discussed in D83477.

This also includes the recommit of "[Matrix] Tighten LangRef definitions and
Verifier checks" which adds improved language reference descriptions of the
matrix intrinsics and verifier checks.

Differential Revision: https://reviews.llvm.org/D83785
2020-07-14 19:58:16 +01:00
Michael Kruse 322e7cfab5 [docs] Update llvm.loop metadata documentation.
Loop metadata nodes do not adhere to the documented property:

(a) LoopIDs are not unique: Any pass that duplicates IR will do it
    including its metadata (e.g. LoopVersioning) such that multiple
    loops are linked with the same LoopID. There is even a test case
    (Transforms/LoopUnroll/unroll-pragmas-disabled.ll) for multiple
    loops with the same LoopID.

(b) LoopIDs are not persistent: Adding or removing an item from a LoopID
    can only be done by creating a new MDNode and assigning it to the
    loop's branch(es). Passes such as LoopUnroll (llvm.loop.unroll.disable)
    and LoopVectorize (llvm.loop.isvectorized) use this to mark loops to
    not be transformed multiple times or to avoid that a LoopVersioned
    original loop is transformed.

Update the documentation according to how llvm.loop is used in practice.

Differential Revision: https://reviews.llvm.org/D55290
2020-07-14 11:03:57 -05:00
Sjoerd Meijer 4ff7ed3310 Revert "[Matrix] Tighten LangRef definitions and Verifier checks."
This reverts commit f4d29d6e8c.

Hm, some build bot failures, reverting it while I investigate that.
2020-07-12 19:19:25 +01:00
Sjoerd Meijer f4d29d6e8c [Matrix] Tighten LangRef definitions and Verifier checks.
This tightens the matrix intrinsic definitions in LLVM LangRef and adds
correspondings checks to the IR Verifier.

Differential Revision: https://reviews.llvm.org/D83477
2020-07-12 19:07:22 +01:00
Sanjay Patel 39009a8245 [DAGCombiner] tighten fast-math constraints for fma fold
fadd (fma A, B, (fmul C, D)), E --> fma A, B, (fma C, D, E)

This is only allowed when "reassoc" is present on the fadd.

As discussed in D80801, this transform goes beyond
what is allowed by "contract" FMF (-ffp-contract=fast).
That is because we are fusing the trailing add of 'E' with a
multiply, but without "reassoc", the code mandates that the
products A*B and C*D are added together before adding in 'E'.

I've added this example to the LangRef to try to clarify the
meaning of "contract". If that seems reasonable, we should
probably do something similar for the clang docs because
there does not appear to be any formal spec for the behavior
of -ffp-contract=fast.

Differential Revision: https://reviews.llvm.org/D82499
2020-07-12 08:51:49 -04:00
JF Bastien 7bf73bcf6d [docs] LLVM Security Group and Process
Summary:
See the corresponding RFC on llvm-dev for a discussion of this proposal.
  http://lists.llvm.org/pipermail/llvm-dev/2019-November/136839.html

Subscribers: jkorous, dexonsmith, arphaman, ributzka, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70326
2020-07-10 15:24:02 -07:00
Matt Arsenault 31f4e43f3f AMDGPU: Remove .value_type from kernel metadata
This doesn't appear used for anything, and is emitted incorrectly
based on the description. This also depends on the IR type, and
pointee element type.
2020-07-10 18:16:31 -04:00
Joel E. Denny 6dda6ff0e0 [FileCheck] Fix up -dump-input* docs
In FileCheck.rst, add `-dump-input-context` and `-dump-input-filter`,
and fix some `-dump-input` documentation.

In `FileCheck -help`, `cl::value_desc("kind")` is being ignored for
`-dump-input-filter`, so just drop it.

Extend `-dump-input=help` to mention FILECHECK_OPTS.
2020-07-10 17:21:01 -04:00
Roman Lebedev 29a9dd5bfe
[Docs] CodingStandards: for_each is discouraged
Summary:
As per disscussion in D83351, using `for_each` is potentially confusing,
at least in regards to inconsistent style (there's less than 100 `for_each`
usages in LLVM, but ~100.000 `for` range-based loops

Therefore, it should be avoided.

Reviewers: dblaikie, nickdesaulniers

Reviewed By: dblaikie, nickdesaulniers

Subscribers: hubert.reinterpretcast, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D83431
2020-07-09 23:10:42 +03:00
Oliver Stannard dc4a6f5db4 [llvm-objdump] Display locations of variables alongside disassembly
This adds the --debug-vars option to llvm-objdump, which prints
locations (registers/memory) of source-level variables alongside the
disassembly based on DWARF info. A vertical line is printed for each
live-range, with a label at the top giving the variable name and
location, and the position and length of the line indicating the program
counter range in which it is valid.

Differential revision: https://reviews.llvm.org/D70720
2020-07-09 09:58:00 +01:00
Vitaly Buka e38727a0bb [StackSafety,NFC] Update documentation
It's follow up for D80908

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D82941
2020-07-08 23:57:13 -07:00
Mitch Phillips 5a98581d19 [NFC] Fix some docs warnings
Summary:
Fixes two minor issues in the docs present under `ninja docs-llvm-html`:

1 - A header is too small:
```
Warning, treated as error:
llvm/llvm/docs/Passes.rst:70:Title underline too short.

``-basic-aa``: Basic Alias Analysis (stateless AA impl)
------------------------------------------------------
```

2 - Multiple definitions on a non-anonymous target (llvm-dev mailing list):
```
Warning, treated as error:
llvm/llvm/docs/DeveloperPolicy.rst:3:Duplicate explicit target name: "llvm-dev mailing list".
```

Reviewers: lattner

Reviewed By: lattner

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D83416
2020-07-08 16:30:12 -07:00
Gui Andrade 89f1ad88b3 [LangRef] Introduce `noundef` attribute for fully defined function params
LLVM currently does not require function parameters or return values
to be fully initialized, and does not care if they are poison. This can
be useful if the frontend ABI makes no such demands, but may prevent
helpful backend transformations in case they do. Specifically, the C
and C++ languages require all scalar function operands to be fully
determined.

Introducing this attribute is of particular use to MemorySanitizer
today, although other transformations may benefit from it as well.
We can modify MemorySanitizer instrumentation to provide modest (17%)
space savings where `frozen` is present.

This commit only adds the attribute to the Language Reference, and
the actual implementation of the attribute will follow in a separate
commit.

Differential Revision: https://reviews.llvm.org/D82316
2020-07-08 19:02:04 +00:00
Arthur Eubanks 470bf7b5a2 [Preallocated] Add @llvm.call.preallocated.teardown
This cleans up the stack allocated by a @llvm.call.preallocated.setup.
Should either call the teardown or the preallocated call to clean up the
stack. Calling both is UB.

Add LangRef.

Add verifier check that the token argument is a @llvm.call.preallocated.setup.

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D83354
2020-07-08 08:48:44 -07:00
Michał Górny 446e3df254 [llvm] [docs] Do not require recommonmark for manpage build
Do not enforce recommonmark dependency if sphinx is called to build
manpages.  In order to do this, try to import recommonmark first
and do not configure it if it's not available.  Additionally, declare
a custom tags for the selected builder via CMake, and ignore
recommonmark import failure when 'man' target is used.

This will permit us to avoid the problematic recommonmark dependency
for the majority of Gentoo users that do not need to locally build
the complete documentation but want to have tool manpages.

Differential Revision: https://reviews.llvm.org/D83161
2020-07-07 20:59:02 +02:00
Chris Lattner 79b30af0ec Expand the LLVM Developer Policy to include new sections on adding
a project to the LLVM Monorepo, and a second about the LLVM
Incubator projects.

Differential Revision: https://reviews.llvm.org/D83182
2020-07-07 10:30:24 -07:00
Nico Weber 003ea14220 fix typos to cycle bots 2020-07-06 20:37:11 -04:00
jasonliu 572dde55ee [XCOFF][AIX] Use 'L..' instead of '.L' for getPrivateGlobalPrefix in DataLayout
Summary:
D80831 changed part of the prefix usage for AIX.
But there are other places getting prefix from DataLayout.
This patch intends to make prefix usage consistent on AIX.

Reviewed by: hubert.reinterpretcast, daltenty

Differential Revision: https://reviews.llvm.org/D81270
2020-07-03 18:25:14 +00:00
Dmitry Preobrazhensky 1c9d681092 [AMDGPU][CODEGEN] Added support of new inline assembler constraints
Added support for constraints 'I', 'J', 'B', 'C', 'DA', 'DB'.

See https://gcc.gnu.org/onlinedocs/gcc/Machine-Constraints.html#Machine-Constraints.

Reviewers: arsenm, rampitec

Differential Revision: https://reviews.llvm.org/D81651
2020-07-02 17:20:15 +03:00
Tony 31fdcf64d2 [AMDGPU] Update DWARF proposal
- Add reference to implicit conversion description.
2020-07-01 20:35:15 +00:00
Tony 76b2d9cbeb [AMDGPU] Correct AMDGPUUsage.rst DW_AT_LLVM_lane_pc example
- Correct typo of DW_OP_xaddr to DW_OP_addrx in AMDGPUUsage.rst for
  DW_AT_LLVM_lane_pc example.

Change-Id: I1b0ee2b24362a0240388e4c2f044c1d4883509b9
2020-07-01 08:23:15 +00:00
Arthur Eubanks f9348f70c2 [Docs][BasicAA] Rename some more basicaa -> basic-aa
Follow up to https://reviews.llvm.org/D82607.
2020-06-30 17:03:45 -07:00
Arthur Eubanks 8b6f675f44 Fix wrong title underline length 2020-06-30 16:02:45 -07:00
Arthur Eubanks 3dfe1440ae [Docs][BasicAA] Rename -basicaa to -basic-aa in docs
Follow up to https://reviews.llvm.org/D82607.
2020-06-30 15:54:28 -07:00
Eric Christopher 8164f69e4c Update the phabricator docs to reflect the monorepo change.
Patch by Nathan Froyd!

Differential Revision: https://reviews.llvm.org/D82389
2020-06-30 10:53:38 -07:00
Jonas Devlieghere 29ea1b4baa [Sphinx] Support older recommonmark versions.
The "new way" of enabling recommonmark is only supported in recommonmark
0.5 and later. Use the deprecated approach with versions of Sphinx that
still support it.

If I understand correctly there's no way to use older versions of
recommonmark (<0.5) with newer versions of Sphinx (>3.0) because the old
approach got removed.

Differential revision: https://reviews.llvm.org/D75284
2020-06-29 09:48:34 -07:00
Mike Edwards 8cd117c24f [LIT] Correcting max-failures option in lit documentation. 2020-06-27 14:57:04 -07:00
Gui Andrade 9aa9855a9c [Docs] BitCodeFormat.rst: List missing attribute codes 2020-06-27 06:34:36 +00:00