GLSL version-aware binding + UniformInfo reflection (BUG-GLES-005)

GLSL backend now provides full infrastructure for runtime binding fallback on GL < 4.2 drivers (e.g., WSL2 Mesa d3d12 with GL 4.1 / GLSL 410). Follows Rust wgpu-hal device.rs:438-461 pattern.

Added

• SupportsExplicitLocations() on Version — gates layout(binding=N) emission on GLSL >= 420 (desktop) or >= 310 (ES). Matches Rust naga mod.rs:213.
• UniformInfo struct — reflection data for uniform/storage blocks (block name, binding, storage flag). Populated during GLSL code generation.
• TranslationInfo.Uniforms — carries uniform block reflection to HAL for post-link glGetUniformBlockIndex/glUniformBlockBinding assignment.
• VersionES300 constant — safe minimum for OpenGL ES contexts.

Fixed

• CI: Codecov OIDC migration — replaced CODECOV_TOKEN secret with OIDC token exchange, fixing GPG signature verification failures.

Quality gates

• TestRustReference: ALL PASS (100%)
• SPIR-V validation: 172/172 (100%)
• golangci-lint: 0 issues
• CI: 10/10 checks pass (Linux, macOS, Windows)

Fixed (DXIL)

• PHI node ordering — Vello path_count.wgsl now passes IDxcValidator. mem2reg Phase B phi instructions grouped at top of basic blocks.

Added

• Coverage waves 3-4: hlsl 70.6%, wgsl/lower 65.3%, msl 64.2%, spirv 76.5%, dxil/emit 37.4%

Metrics (unchanged)

• gg production: 61/61 (100%)
• IDxcValidator: 161/170 (94.7%)
• DXC golden diff=0: 105 (55.1%)

Enterprise Architecture Refactoring (ARCH-001)

All backends restructured following DXIL internal package pattern.

Internal packages (DXIL pattern applied to all backends)

• glsl/, msl/, hlsl/, spirv/ → internal/codegen/
• wgsl/ → internal/parser/ + internal/lower/
• Shared: internal/textutil/ (IndentWriter DRY), internal/backend/ (namer, sig packing), internal/registry/ (type dedup)
• Public API: real types, not aliases. go doc shows full struct definitions.

Test coverage (12/18 packages ≥80%)

Error handling

• 13 panics → error returns across all backends
• 2 nilerr fixes (spirv silently swallowed errors)
• Unsupported stage validation (mesh/task → clear error)
• 11 dead functions removed (-929 LOC)

Metrics (unchanged)

• gg production: 61/61 (100%)
• DXC golden diff=0: 105 (55.1% parity)
• IDxcValidator: 161/170 (94.7%)
• golangci-lint: 0 issues

gg Production: 61/61 VALID (100%) 🏆

Zero DXIL validation failures across all gg production entry points.

Fixed

• Array-of-vector flattening (BUG-DXIL-041) — fine.wgsl "Invalid record" caused by 3 bugs in flattened array<vec4<f32>, N> locals: GEP index not scaled by vector width, single-scalar load instead of multi-scalar, garbage component IDs.

• All golangci-lint issues resolved — extracted goconst constants, removed unused nolint directives, excluded keyword maps and tmp/ from lint.

Metrics

DXIL Architecture Push

Architectural improvements

• Workgroup struct decomposition — per-member globals with MSVC-mangled names
• ViewID ExprAlias/ExprPhi — precise post-mem2reg dataflow
• StmtEmit range merging — cross-range reassociation
• Instruction scheduling infrastructure — eval-right-first, resource read detection

Optimizations

• Constant folding (int-to-float casts, bitcast float→i32)
• Alignment encoding fix (log2+1)
• Mul-to-shl in CBV/UAV paths
• TBAA normalizer

DXIL Parity Push: 104 golden diff=0, 54.5% line parity

Crossed 100 diff=0 and 50% parity milestones. +10 diff=0 shaders, +6.4pp parity.

New optimizations

Bug fixes

Metrics

Note: DXIL backend is experimental.

WGSL Validation Hardening — 8 spec-compliance fixes

All 8 fixes independently verified against Rust naga — identical rejection behavior.

Fixes

35+ new unit tests. Reported by @maxsupermanhd (#66).

Fixed

• Function call argument type validation (#66).
  WGSL lowerer now validates argument count and types against function
  parameters. Passing vec2<u32> where u32 is expected now produces a
  clear compile error instead of silently generating invalid shader code
  that crashes at pipeline creation. Reported by @maxsupermanhd.

9 test cases covering shape mismatches, count mismatches, and abstract type concretization.

DXIL Parity Push: 94 golden diff=0, 48.1% line parity

+22 diff=0 shaders compared to v0.17.4 baseline. Seven enterprise-level fixes.

New optimizations

• Single-store local promotion — eliminates alloca/store/load chains for vertex/fragment output staging, matching DXC's direct storeOutput pattern (+6 diff=0)
• Strength reduction — urem x, 2^N → and x, (2^N-1) at emit time

DXC parity fixes

• Sampler heap after input loads — DXC emit ordering for fragment shaders (+3 diff=0)
• HLSL namer suffix — trailing _ on resource names ending with digits/keywords (+2 diff=0)
• Input used mask sorted order — fix extended properties for multi-struct fragment inputs (+1 diff=0)
• Fragment input signature ordering — LOC semantics before SV_Position
• Raw buffer i32 overload — float loads via i32 + bitcast, matching DXC ByteAddressBuffer convention

Metrics

Note: DXIL backend is experimental. v0.18.0 will mark DXIL as stable.

DXIL Parity Push + ir.TypeSize for wgpu VAL-006

New: ir.TypeSize() for buffer size validation

Shared type size calculation matching Rust naga's TypeInner::try_size(gctx). Returns byte sizes for all IR types following WGSL/WebGPU alignment rules. Enables wgpu late buffer binding size validation (VAL-006). 23 unit tests.

DXIL parity improvements (+10 golden diff=0)

Metrics

Note: DXIL backend is experimental. v0.18.0 will mark DXIL as stable.