Emit the "[loop]" attribute on "for" and "while" so that FXC does not
attempt to unroll them. This is to work around an FXC bug where it fails
to unroll loops with gradient operations.
FXC ostensibly unrolls such loops because gradient operations require
uniform control flow, and loops that have varying iterations may
possibly not be uniform. Tint will eventually validate that control flow
is indeed uniform, so forcing FXC to avoid unrolling in these cases
should be fine.
Bug: tint:1112
Change-Id: I10077f8b62fbbb230a0003f3864c75a8fe0e1d18
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/69880
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
Commit-Queue: Antonio Maiorano <amaiorano@google.com>
Add `transform::DecomposeStridedMatrix`, which replaces matrix members of storage or uniform buffer structures, that have a [[stride]] decoration, into an array
of N column vectors.
This is required to correctly handle `mat2x2` matrices in UBOs, as std140 rules will expect a default stride of 16 bytes, when in WGSL the default structure layout expects a stride of 8 bytes.
Bug: tint:1047
Change-Id: If5ca3c6ec087bbc1ac31a8d9a657b99bf34042a4
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/59840
Reviewed-by: David Neto <dneto@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Antonio Maiorano
Ben Clayton