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8235 Commits

Author SHA1 Message Date
Florian Hahn
3ac0102ef0 [docs] Mention LLVM_ENABLE_MODULES. 2020-08-04 16:59:39 +01:00
Fangrui Song
f6b39f50d1 [llvm-symbolizer] Switch command line parsing from llvm::cl to OptTable
for the advantage outlined by D83639 ([OptTable] Support grouped short options)

Some behavior changes:

* -i={0,false} is removed. Use --no-inlines instead.
* --demangle={0,false} is removed. Use --no-demangle instead
* -untag-addresses={0,false} is removed. Use --no-untag-addresses instead

Added a higher level API OptTable::parseArgs which handles optional
initial options populated from an environment variable, expands response
files recursively, and parses options.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D83530
2020-08-04 08:53:15 -07:00
Simon Pilgrim
1832d64356 Fix sphinx "Title underline too short" warning 2020-08-04 16:36:00 +01:00
Simon Pilgrim
0fc57afbbe Fix sphinx indentation warning to stop newline in byref section html output. 2020-08-04 16:12:50 +01:00
Simon Pilgrim
5f8db00af1 Fix sphinx indentation warning.
Don't double indent and make it clear we're referting to the latency mode.
2020-08-04 15:57:46 +01:00
Fangrui Song
5554745259 Add test utility 'split-file'
See https://lists.llvm.org/pipermail/llvm-dev/2020-July/143373.html
"[llvm-dev] Multiple documents in one test file" for some discussions.

This patch has explored several alternatives. The current semantics are similar to
what @dblaikie proposed.
`split-file filename output` splits the input file into multiple parts separated by
regex `^(.|//)--- filename` and write each part to the file `output/filename`
(`filename` can include path separators).

Use case A (organizing input of different formats (e.g. linker
script+assembly) in one file).

```
# RUN: split-file %s %t
# RUN: llvm-mc %t/asm -o %t.o
# RUN: ld.lld -T %t/lds %t.o -o %t
This is sometimes better than the %S/Inputs/ approach because the user
can see the auxiliary files immediately and don't have to open another file.

# asm
...
# lds
...
```

Use case B (for utilities which don't have built-in input splitting
feature):

```
// RUN: split-file %s %t
// RUN: llc < %t/1.ll | FileCheck %s --check-prefix=CASE1
// RUN: llc < %t/2.ll | FileCheck %s --check-prefix=CASE2
Combing tests prudently can improve readability.
For example, when testing parsing errors if the recovery mechanism isn't possible,
grouping the tests in one file can more readily see test coverage/strategy.

//--- 1.ll
...
//--- 2.ll
...
```

Since this is a new utility, there is no git history concerns for
UpperCase variable names. I use lowerCase variable names like mlir/lld.

Reviewed By: jhenderson, lattner

Differential Revision: https://reviews.llvm.org/D83834
2020-08-03 20:42:09 -07:00
Florian Hahn
5eea1c2f70 Recommit "[IPConstProp] Remove and move tests to SCCP."
This reverts commit 59d6e814ce0e7b40b7cc3ab136b9af2ffab9c6f8.

The cause for the revert (3 clang tests running opt -ipconstprop) was
fixed by removing those lines.
2020-08-02 22:23:54 +01:00
Fangrui Song
bf5334b827 [Support][CommandLine] Delete unused llvm:🆑:ParseEnvrironmentOptions
The function was added in 2003. It is not used and can be emulated with ParseCommandLineOptions.
2020-07-31 10:48:09 -07:00
Mircea Trofin
629123ee54 [doc] Describe the header guard style
clang-tidy's llvm-header-guard rule references the LLVM style - where it's
missing.

Differential Revision: https://reviews.llvm.org/D84989
2020-07-30 16:08:07 -07:00
Florian Hahn
1316430704 Revert "[IPConstProp] Remove and move tests to SCCP."
This reverts commit e77624a3be942c7abba48942b3a8da3462070a3f.

Looks like some clang tests manually invoke -ipconstprop via opt.....
2020-07-30 13:06:54 +01:00
Florian Hahn
ce3655671a [IPConstProp] Remove and move tests to SCCP.
As far as I know, ipconstprop has not been used in years and ipsccp has
been used instead. This has the potential for confusion and sometimes
leads people to spend time finding & reporting bugs as well as
updating it to work with the latest API changes.

This patch moves the tests over to SCCP. There's one functional difference
I am aware of: ipconstprop propagates for each call-site individually, so
for functions that are called with different constant arguments it can sometimes
produce better results than ipsccp (at much higher compile-time cost).But
IPSCCP can be thought to do so as well for internal functions and as mentioned
earlier, the pass seems unused in practice (and there are no plans on working
towards enabling it anytime).

Also discussed on llvm-dev:
http://lists.llvm.org/pipermail/llvm-dev/2020-July/143773.html

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D84447
2020-07-30 12:36:27 +01:00
Tony
66a4f3eb09 [AMDGPU] Fix DWARF extensions User Guide table of contents 2020-07-30 05:10:21 +00:00
Tony
57dd67ea2c [AMDGPU] DWARF proposal changes
- Clarify that these are extensions to DWARF 5 and not as yet a
  proposal.

Reviewed By: scott.linder

Differential Revision: https://reviews.llvm.org/D70523
2020-07-30 05:07:09 +00:00
Tony
a3714ce03c [AMDGPU] DWARF proposal changes for expression context
- Clarify what context is used in DWARF expression evaluation.

- Define location descriptions to fully resolve the context and so
  include the context in their result.

- As a consequence of location descriptions being fully resoved,
  change address spaces so only a swizzled and unswizzled private
  address space is defined. The lane is now part of the location
  description context.

- Clarify how call frame information is used to fully resolve
  expressions that specify registers.

Reviewed By: scott.linder

Differential Revision: https://reviews.llvm.org/D70523
2020-07-30 01:59:22 +00:00
Varun Gandhi
830a8aba04 [docs] [lit] Add a more helpful description for lit.py's -s flag.
Reviewed By: yln

Differential Revision: https://reviews.llvm.org/D82808
2020-07-28 14:36:03 -07:00
Fangrui Song
8a55d3cc1c Revert D83834 "Add test utility 'extract'"
This reverts commit d054c7ee2e9f4f98af7f22a5b00a941eb919bd59.

There are discussions about the utility name, its functionality and user interface.
Revert before we reach consensus.
2020-07-28 13:26:33 -07:00
Arthur Eubanks
8a584da153 [FunctionAttrs] Rename functionattrs -> function-attrs
To match NewPM pass name, and also for readability.
Also rename rpo-functionattrs -> rpo-function-attrs while we're here.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D84694
2020-07-28 09:09:13 -07:00
Jinsong Ji
a3d207d6bc Re-land "[PowerPC] Remove QPX/A2Q BGQ/BGP CNK support"
This reverts commit bf544fa1c3cb80f24d85e84559fb11193846259f.

Fixed the typo in PPCInstrInfo.cpp.
2020-07-28 14:00:11 +00:00
Wei Mi
51d4708437 Supplement instr profile with sample profile.
PGO profile is usually more precise than sample profile. However, PGO profile
needs to be collected from loadtest and loadtest may not be representative
enough to the production workload. Sample profile collected from production
can be used as a supplement -- for functions cold in loadtest but warm/hot
in production, we can scale up the related function in PGO profile if the
function is warm or hot in sample profile.

The implementation contains changes in compiler side and llvm-profdata side.
Given an instr profile and a sample profile, for a function cold in PGO
profile but warm/hot in sample profile, llvm-profdata will either mark
all the counters in the profile to be -1 or scale up the max count in the
function to be above hot threshold, depending on the zero counter ratio in
the profile. The assumption is if there are too many counters being zero
in the function profile, the profile is more likely to cause harm than good,
then llvm-profdata will mark all the counters to be -1 indicating the
function is hot but the profile is unaccountable. In compiler side, if a
function profile with all -1 counters is seen, the function entry count will
be set to be above hot threshold but its internal profile will be dropped.

In the long run, it may be useful to let compiler support using PGO profile
and sample profile at the same time, but that requires more careful design
and more substantial changes to make two profiles work seamlessly. The patch
here serves as a simple intermediate solution.

Differential Revision: https://reviews.llvm.org/D81981
2020-07-27 20:17:40 -07:00
Jinsong Ji
89408b2ab3 Revert "[PowerPC] Remove QPX/A2Q BGQ/BGP CNK support"
This reverts commit adffce71538e219aab4eeb024819baa7687262ff.

This is breaking test-suite, revert while investigation.
2020-07-27 21:07:00 +00:00
Jinsong Ji
2d65e976a4 [PowerPC] Remove QPX/A2Q BGQ/BGP CNK support
Per RFC http://lists.llvm.org/pipermail/llvm-dev/2020-April/141295.html
no one is making use of QPX/A2Q/BGQ/BGP CNK anymore.

This patch remove the support of QPX/A2Q in llvm, BGQ/BGP in clang,
CNK support in openmp/polly.

Reviewed By: hfinkel

Differential Revision: https://reviews.llvm.org/D83915
2020-07-27 19:24:39 +00:00
Matt Morehouse
964edac32c Replace fuzzer::FuzzerDriver's INTERFACE marking with new LLVMRunFuzzerDriver.
This adds a new extern "C" function that serves the same purpose. This removes the need for external users to depend on internal headers in order to use this feature. It also standardizes the interface in a way that other fuzzing engines will be able to match.

Patch By: IanPudney

Reviewed By: kcc

Differential Revision: https://reviews.llvm.org/D84561
2020-07-27 18:38:04 +00:00
Vy Nguyen
0724050861 Reland [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

New change: check for existence of field `cycles` in perf_branch_entry before enabling this mode.
This should prevent compilation errors when building for older kernel whose headers don't support it.
2020-07-27 12:38:05 -04:00
Afanasyev Ivan
2f03196312 [Docs] remove unused arguments in documentation examples on vectorization passes
Reviewers: nadav, tyler.nowicki

Reviewed By: nadav

Differential Revision: https://reviews.llvm.org/D83851
2020-07-27 10:20:26 +01:00
Fangrui Song
4f0382f382 Add test utility 'extract'
See https://lists.llvm.org/pipermail/llvm-dev/2020-July/143373.html
"[llvm-dev] Multiple documents in one test file" for some discussions.

`extract part filename` splits the input file into multiple parts separated by
regex `^(.|//)--- ` and extract the specified part to stdout or the
output file (if specified).

Use case A (organizing input of different formats (e.g. linker
script+assembly) in one file).

```
// RUN: extract lds %s -o %t.lds
// RUN: extract asm %s -o %t.s
// RUN: llvm-mc %t.s -o %t.o
// RUN: ld.lld -T %t.lds %t.o -o %t
This is sometimes better than the %S/Inputs/ approach because the user
can see the auxiliary files immediately and don't have to open another file.
```

Use case B (for utilities which don't have built-in input splitting
feature):

```
// RUN: extract case1 %s | llc | FileCheck %s --check-prefix=CASE1
// RUN: extract case2 %s | llc | FileCheck %s --check-prefix=CASE2
Combing tests prudently can improve readability.
This is sometimes better than having multiple test files.
```

Since this is a new utility, there is no git history concerns for
UpperCase variable names. I use lowerCase variable names like mlir/lld.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D83834
2020-07-23 19:15:35 -07:00
Roman Lebedev
39bcc4be1d [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
7434f60b1b [X86][docs] Add mention of removal of 'mpx' backend feature to the release notes.
I removed the feature from X86.td in ebe5f17f9c396f14742a7c747951b65eaada158e
2020-07-23 08:25:34 -07:00
Russell Gallop
74bcbfec76 [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
1f1171c0d4 [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
6e98d8a897 [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
3196db98ad Fix typo in tutorial 2020-07-21 17:28:24 +02:00
Yuanfang Chen
bf8086d1c1 [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
0a592fd282 [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
ea505ad2f6 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
9d37b40f76 [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
4336e89619 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
17ad6e2f24 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
a4af7cf1e9 [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
6bfa8ac3f9 Fix incorrect file path in documentation 2020-07-16 15:53:11 -04:00
Jinsong Ji
f958fcb9e1 [docs] fix ident in llvm-exegesis.rst 2020-07-16 17:30:09 +00:00
Jinsong Ji
eacbb3ef70 [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
86e9087897 [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
e1b03eb222 Follow up of 2b3c505d0f6e: fixed a typo, and added some more formatting. NFC. 2020-07-16 11:16:48 +01:00
Mehdi Amini
6f679f30fe 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
0080e83362 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
7ddc914b02 Bump the trunk major version to 12
and clear the release notes.
2020-07-15 12:05:05 +02:00
Tim Northover
80a21440b3 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
1a682582ae [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
186e2229e8 [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
ab1d7d92a0 Revert "[Matrix] Tighten LangRef definitions and Verifier checks."
This reverts commit f4d29d6e8c43cfd924d9d7cc1ac0c269b2788e75.

Hm, some build bot failures, reverting it while I investigate that.
2020-07-12 19:19:25 +01:00