In order to preserve padding properly for MSL, we need to use its
packed_vec type for all vec3 types in storage buffers, not just struct
members. This commit includes a complete rewrite of the PackedVec3
transform to achieve this. The key details are:
* An internal `__packed_vec3<>` type was added, which corresponds to a
`type::Vector` with an additional flag to indicate that it will be
emitted as packed vector.
* The `PackedVec3` transform replaces all vec3 types used in
host-shareable address spaces with the internal `__packed_vec3`
type. This includes vec3 types that appear as the store type of a
pointer.
* When used as an array element, these `__packed_vec3` types are
wrapped in a struct that contains a single `__packed_vec3`
member. This allows us to add an `@align()` attribute that ensures
that `array<vec3<T>>` still has the correct array element stride.
* When the `vec3<T>` appears as a struct member in the input program,
we apply the `@align()` to that member to ensure that we do not
change its offset.
* Matrix types with three rows that are used in memory are replaced
with an array of columns, where each column uses a `__packed_vec3`
inside an aligned wrapper structure as above.
* Accesses to host-shareable memory that involve any of these types
invoke a "pack" or "unpack" helper function to convert them to the
equivalent type that uses `__packed_vec3` or a regular `vec3` as
required.
* The `chromium_internal_relaxed_uniform_layout` extension is used to
avoid issues where modifying a type in the uniform address space
triggers stricter layout validation rules.
Bug: tint:1571
Fixed: tint:1837
Change-Id: Idaf2da2f5bcb2be00c85ec657edfb614186476bb
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/121200
Reviewed-by: Ben Clayton <bclayton@google.com>
Commit-Queue: James Price <jrprice@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
These have been warnings for multiple months.
Time to properly turn this on.
Bug: tint:880
Change-Id: I3b38f672309b5acd48c12a38dc5a1675f3c62470
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/103480
Commit-Queue: Ben Clayton <bclayton@google.com>
Reviewed-by: Dan Sinclair <dsinclair@chromium.org>
Add additional nodes to capture places where control flow is changed
(if, switch, for, short-circuiting op, function call), and use these
to show the actual point at which control flow became non-uniform as a
result of a non-uniform value.
Do this recursively, to capture cases where control flow becomes
non-uniform after a function call statement.
Bug: tint:880
Change-Id: Ied92d690f98a5c11a1892eef500a50d0f123943d
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/89862
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
Show the original source of non-uniformity when producing errors from
the uniformity analysis.
Bug: tint:880
Change-Id: Id386ae8fa5ff1b1443d54c0b5ef12ab76b3b3f13
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/89723
Reviewed-by: Ben Clayton <bclayton@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
This implements the uniformity analysis as currently described in the
WGSL specification. Uniformity issues are presented as warnings, and
will be switched to errors in a future release.
A follow-up patch will improve the error messages, which currently
just show the point at which a uniformity was detected.
In a future release, once we have obtained initial feedback from
users, uniformity issues will become errors.
Bug: tint:880
Change-Id: I7d0b3080932c786c5d50b55720fec6d19f00d356
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/88368
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Alan Baker <alanbaker@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>