Author :
Shahbaz Youssefi
Date :
2021-07-13 14:10:41
Hash :9c6fb52c Message :Vulkan: SPIR-V Gen: Assignment between mismatching SPIR-V types
In general, GLSL qualifiers translate to SPIR-V decorations on SPIR-V
variables. In the case of blocks (struct or interface block),
OpMemberDecorate is used, which due to its specification in SPIR-V, can
only apply decorations to direct members of a block. This makes it
impossible for example to decorate a nested member of a block through
its variable id.
As such, some decorations such as RowMajor and Invariant apply to
members of a block given its _type_ id. Unfortunately SPIR-V requires
ArrayStride to also be applied to a type directly, rather than a member
of a block. This implies that some types, such as structs used in
uniform/buffer interface block, or decorated with invariant or
row_major, as well as arrays (of any type) used inside and outside
interface blocks to produce different SPIR-V types from the same GLSL
type. The SpirvTypeSpec data previously introduced specialize these
types.
It's necessary to "cast" between these types when needed. The
translator handles casts at load/store boundary:
- Upon load, the value is cast to the type with the default
SpirvTypeSpec.
- Upon store, the value is cast from the default to the store target
SpirvTypeSpec.
- All intermediate results use the default SpirvTypeSpec.
Bug: angleproject:4889
Change-Id: I6fa28e518ec6b517ff163f44b6892859eb4b10fd
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3026145
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>
Reviewed-by: Tim Van Patten <timvp@google.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>