This adds WebAssembly support for the new [Lime1 CPU].
First, this defines some new target features. These are subsets of
existing
features that reflect implementation concerns:
- "call-indirect-overlong" - implied by "reference-types"; just the
overlong
encoding for the `call_indirect` immediate, and not the actual reference
types.
- "bulk-memory-opt" - implied by "bulk-memory": just `memory.copy` and
`memory.fill`, and not the other instructions in the bulk-memory
proposal.
Next, this defines a new target CPU, "lime1", which enables
mutable-globals,
bulk-memory-opt, multivalue, sign-ext, nontrapping-fptoint,
extended-const,
and call-indirect-overlong. Unlike the default "generic" CPU, "lime1" is
meant
to be frozen, and followed up by "lime2" and so on when new features are
desired.
[Lime1 CPU]:
https://github.com/WebAssembly/tool-conventions/blob/main/Lime.md#lime1
---------
Co-authored-by: Heejin Ahn <aheejin@gmail.com>
This defines some new target features. These are subsets of existing
features that reflect implementation concerns:
- "call-indirect-overlong" - implied by "reference-types"; just the
overlong encoding for the `call_indirect` immediate, and not the actual
reference types.
- "bulk-memory-opt" - implied by "bulk-memory": just `memory.copy` and
`memory.fill`, and not the other instructions in the bulk-memory
proposal.
This is split out from https://github.com/llvm/llvm-project/pull/112035.
---------
Co-authored-by: Heejin Ahn <aheejin@gmail.com>
This commit implements the [wide-arithmetic] proposal which has recently
reached phase 2 in the WebAssembly proposals process. The goal here is
to implement support in LLVM for emitting these instructions which are
gated behind a new feature flag by default. A new `wide-arithmetic`
feature flag is introduced which gates these four new instructions from
being emitted.
Emission of each instruction itself is relatively simple given LLVM's
preexisting lowering rules and infrastructure. The main gotcha is that
due to the multi-result nature of all of these instructions it needed
the lowerings to be implemented in C++ rather than in TableGen.
[wide-arithmetic]: https://github.com/WebAssembly/wide-arithmetic
I'm not entirely sure what the criteria for 'bleeding-edge' used to be,
but at this point it seems to be the set of all added features in LLVM.
This adds remaining features to bleeding-edge config.
#80923 newly enabled multivalue and reference-types in the generic CPU.
But enabling reference-types ended up breaking up Wasm's Chromium CI
(https://chromium-review.googlesource.com/c/emscripten-releases/+/5500231)
because the way the table index is encoded is different from MVP (u32)
vs. reference-types (LEB), which caused different encodings for
`call_indirect`.
And Chromium CI's and Emscripten's minimum required node version is v16,
which does not yet support reference-types, which does not recognize
that table index encoding. reference-types is first supported in node
v17.2.
We knew the current minimum required node for Emscripten (v16) did not
support reference-types, but thought it was fine because unless you
explicitly use `__funcref` or `__externref` things would be fine, and if
you want to use them explicitly, you would have a newer node. But it
turned out it also affected the encoding of `call_indirect`.
While we are discussing the potential solutions, I will disable
reference-types to unblock the rolls.
This currently only defines a constant, but in the future will be used
to gate builtins for experimenting and prototyping half-precision
proposal (https://github.com/WebAssembly/half-precision).
Adding to allow users to get this flag into the target features section for
future use cases.
Reviewed By: tlively, aheejin
Differential Revision: https://reviews.llvm.org/D158409
This commit implements support for WebAssembly table types and
respective builtins. Table tables are WebAssembly objects to store
reference types. They have a large amount of semantic restrictions
including, but not limited to, only being allowed to be declared
at the top-level as static arrays of zero-length. Not being arguments
or result of functions, not being stored ot memory, etc.
This commit introduces the __attribute__((wasm_table)) to attach to
arrays of WebAssembly reference types. And the following builtins to
manage tables:
* ref __builtin_wasm_table_get(table, idx)
* void __builtin_wasm_table_set(table, idx, ref)
* uint __builtin_wasm_table_size(table)
* uint __builtin_wasm_table_grow(table, ref, uint)
* void __builtin_wasm_table_fill(table, idx, ref, uint)
* void __builtin_wasm_table_copy(table, table, uint, uint, uint)
This commit also enables reference-types feature at bleeding-edge.
This is joint work with Alex Bradbury (@asb).
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D139010
Reorganize clang::Builtin::Info to have them naturally align on 4 bytes
boundaries.
Instead of storing builtin headers as a straight char pointer, enumerate
them and store the enum. It allows to use a small enum instead of a
pointer to reference them.
On a 64 bit machine, this brings sizeof(clang::Builtin::Info) from 56
down to 48 bytes.
On a release build on my Linux 64 bit machine, it shrinks the size of
libclang-cpp.so by 193kB.
The impact on performance is negligible in terms of instruction count,
but the wall time seems better, see
https://llvm-compile-time-tracker.com/compare.php?from=b3d8639f3536a4876b511aca9fb7948ff9266cee&to=a89b56423f98b550260a58c41e64aff9e56b76be&stat=task-clock
Differential Revision: https://reviews.llvm.org/D142024
This avoids recomputing string length that is already known at compile time.
It has a slight impact on preprocessing / compile time, see
https://llvm-compile-time-tracker.com/compare.php?from=3f36d2d579d8b0e8824d9dd99bfa79f456858f88&to=e49640c507ddc6615b5e503144301c8e41f8f434&stat=instructions:u
This a recommit of e953ae5bbc313fd0cc980ce021d487e5b5199ea4 and the subsequent fixes caa713559bd38f337d7d35de35686775e8fb5175 and 06b90e2e9c991e211fecc97948e533320a825470.
The above patchset caused some version of GCC to take eons to compile clang/lib/Basic/Targets/AArch64.cpp, as spotted in aa171833ab0017d9732e82b8682c9848ab25ff9e.
The fix is to make BuiltinInfo tables a compilation unit static variable, instead of a private static variable.
Differential Revision: https://reviews.llvm.org/D139881
We previously had logic to disable pthreads, set the ThreadModel to Single, and
disable thread-safe statics when the atomics target features is disabled, since
that means that the resulting program will not be used in a threaded context.
Similarly check for the presence of the bulk-memory feature, since that is also
necessary to produce multithreaded programs.
Differential Revision: https://reviews.llvm.org/D121014
The superclass method handles a bunch of useful things. For example
it applies flags such as `-fnew-alignment` which doesn't work without
this patch.
Differential Revision: https://reviews.llvm.org/D118573
When we don't enable atomics we completely disabled threading in
which case there is no point in generating thread safe code for
static initialization.
This should always be safe because, in WebAssembly, it is not
possible to link object compiled without the atomics feature into a
mutli-threaded program.
See https://github.com/emscripten-core/emscripten/pull/16152
Differential Revision: https://reviews.llvm.org/D118571
This change implements new DAG notes GLOBAL_GET/GLOBAL_SET, and
lowering methods for load and stores of reference types from IR
globals. Once the lowering creates the new nodes, tablegen pattern
matches those and converts them to Wasm global.get/set.
Reviewed By: tlively
Differential Revision: https://reviews.llvm.org/D95425
Now that the WebAssembly SIMD specification is finalized and engines are
generally up-to-date, there is no need for a separate target feature for gating
SIMD instructions that engines have not implemented. With this change,
v128.const is now enabled by default with the simd128 target feature.
Differential Revision: https://reviews.llvm.org/D98457
When the -matomics feature is not enabled, disable POSIXThreads
mode and set the thread model to Single, so that we don't predefine
macros like `__STDCPP_THREADS__`.
Differential Revision: https://reviews.llvm.org/D96091
Properly set "simd128" in the feature map when "unimplemented-simd128"
is requested.
initFeatureMap is used to create the feature vector used by
handleTargetFeatures. There are later calls to initFeatureMap in
CodeGen that were using these flags to recreate the map. But the
original feature vector should be passed to those calls. So that
should be enough to rebuild the map.
The only issue seemed to be that simd128 was not enabled in the
map by the first call to initFeatureMap. Using the SIMDLevel set
by handleTargetFeatures in the later calls allowed simd128 to be
set in the later versions of the map.
To fix this I've added an override of setFeatureEnabled that
will update the map the first time with the correct simd dependency.
Differential Revision: https://reviews.llvm.org/D85806
Summary:
For now, this ABI simply expands all possible aggregate arguments and
returns all possible aggregates directly. This ABI will change rapidly
as we prototype and benchmark a new ABI that takes advantage of
multivalue return and possibly other changes from the MVP ABI.
Reviewers: aheejin, dschuff
Subscribers: sbc100, jgravelle-google, sunfish, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D72972
Summary:
This adds the reference types target feature. This does not enable any
more functionality in LLVM/clang for now, but this is necessary to embed
the info in the target features section, which is used by Binaryen and
Emscripten. It turned out that after D69832 `-fwasm-exceptions` crashed
because we didn't have the reference types target feature.
Reviewers: tlively
Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, sunfish, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D73320
Summary:
These features will both be implemented soon, so I thought I would
save time by adding the boilerplate for both of them at the same time.
Reviewers: aheejin
Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, sunfish, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D62047
llvm-svn: 361516
Summary:
This feature is not actually used for anything in the WebAssembly
backend, but adding it allows users to get it into the target features
sections of their objects, which makes these objects
future-compatible.
Reviewers: aheejin, dschuff
Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, jdoerfert, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D60013
llvm-svn: 357321
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
