0044-sm69-required-features.md

title	0044 - SM69 Required Features
params	authors sponsors status damyanp Damyan Pepper damyanp Damyan Pepper Accepted

Instructions

• Planned Version: SM 6.9

Introduction

This proposal makes the following optional features required features for Shader Model 6.9:

• D3D12_FEATURE_DATA_D3D12_OPTIONS4.Native16BitShaderOpsSupported
• D3D12_FEATURE_DATA_D3D12_OPTIONS1.WaveOps
• D3D12_FEATURE_DATA_D3D12_OPTIONS1.Int64ShaderOps

Motivation

Shader Model 6.9 introduces vectorized DXIL (0030) which means that we need to add new conformance tests for all DXIL operations that now accept vectors. Some of these operations are optional, and so we'd need to test combinations of these features.

In practice every device that supports SM 6.9 is expected to support these operations, so we can simplify the testing matrix by assuming that these operations are supported.

Proposed solution

A new HLK test will be added that verifies that for SM 6.9 the optional features listed above are supported.

The other tests will be written assuming that these features are supported.

Alternatives Considered

Require double precision support

Across the broader ecosystem there are devices that do not support double precision, and since most GPU programmer models are "fast math" by default there doesn't seem to be a strong need for double precision as a required feature.