[workstream] Semantics

[damyanp]

This covers parameter handling for entry points along with semantics and
inter-stage signature construction.

Milestones

Compile a runnable shader from clang (#7)

• Support SV_GroupIndex and SV_DispatchThreadID used with basic scalar/vector input types for target shader.

Compile particle_life.hlsl (#20)

Compile all DML shaders, and they pass the validator (#11)

• Support all compute semantics and lowering to DXIL ops
• Generalized Semantic and Signature Point implementation plan
• Capture Signature Element mapping on entry parameters in AST
• Type checking for semantics

Render Simple Triangle (#13)

Render Textured Triangle (#14)

• Prefix-stable Signature Element packing

Render Mesh (#15)

Pixel and Vertex Shaders (#16)

• Semantics on fields in structure arguments
• Structure flattening and semantic assignment for Signature Elements
• Generate input/output translation for entry wrapper

Mesh Shaders (#17)

• Specialized mesh shader parameter handling (vertices, primitives, indices)

Ray Tracing (#18)

• Payload Access Qualifiers

V1 Release (#19)

• Geometry Shaders
  • Specialized geometry shader input/output object handling (input prims, stream objects)
• Tesselation Shaders
  • Special shader input/output objects (patches, patch constant params)
  • Patch Constant Function parameter/signature handling

[damyanp]

Make sure that microsoft/hlsl-specs#309 is accounted for in the plan here.