WGSL states that `f32` is a IEEE-754 binary32. mediump precision guarantees are much smaller than highp, and using mediump can break code generated by tint.
Change-Id: I8a129c4c8ac078c785e0d5d7d21f19ed6b3620b5
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/123400
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>
Reviewed-by: Stephen White <senorblanco@chromium.org>
Discard statements no longer affect the behavior or uniformity
analysis. Update the resolver, validator, and several tests to reflect
this.
Some E2E tests were removed as they had loops that are now considered
to be infinite.
Use the DemoteToHelper transform to emulate the correct semantics on
platforms where discard is (or may) terminate the invocation in a
manner that would affect derivative operations.
We no longer need the UnwindDiscardFunctions transform for HLSL, which
already implements the correct semantics. However, we still run the
DemoteToHelper transform for the HLSL backend due to issues with FXC's
handling of discard statements (see crbug.com/tint/1118).
Fixed: tint:1723
Change-Id: Ib49ff187919ae81c4af8675e1b66acd57e2ff7d2
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/109003
Reviewed-by: Ben Clayton <bclayton@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: James Price <jrprice@google.com>
Ben Clayton
James Price