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>
This reverts commit e5dbe24e94.
Reason for revert: Makes the Tint-Dawn roll fails because of
MSL compilation errors on as_type<uint>(-2147483648):
as_type cast from 'long' to 'uint' (aka 'unsigned int') is not allowed
as_type<uint>(-2147483647) compiles fine, so this is most
likely because the MSL compiler types the literal as a long
(since without the - it is larger than the max int32).
Original change's description:
> MSL writer: make signed int overflow defined behaviour
>
> Bug: tint:124
> Change-Id: Icf545b633d6390ceb7f639e80111390005e311a1
> Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/60100
> Kokoro: Kokoro <noreply+kokoro@google.com>
> Commit-Queue: Antonio Maiorano <amaiorano@google.com>
> Reviewed-by: David Neto <dneto@google.com>
TBR=dneto@google.com,bclayton@google.com,jrprice@google.com,amaiorano@google.com,noreply+kokoro@google.com,tint-scoped@luci-project-accounts.iam.gserviceaccount.com
Change-Id: I3e3384a9185013bb141a1b7b9b22bad8571bbc50
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: tint:124
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/60345
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Ben Clayton <bclayton@google.com>
Auto-Submit: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Ben Clayton <bclayton@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>