glslang-16.4.0

[Bruce Dubbs]

New minor version.

[Joe Locash]

## 16.4.0 2026-07-14

### Descriptor Heap

* Implement `GLSL_EXT_structured_descriptor_heap` with SPIR-V layout generation, heap offset access, buffer references, matrix layout decorations, and correct `readonly`/`writeonly` qualifier propagation for buffer and image descriptors
* Fix descriptor heap-bound buffer access to use typed pointers
* Omit `NonUniform` decoration when using descriptor heaps, as the SPIR-V spec does not require it
* Add `--relax-set-binding-limits` option to allow large `layout(set)` and `layout(binding)` values for descriptor heap-style workflows with sparse set spaces
* Reject combined image samplers with `descriptor_heap`

### Compute Shader Derivatives

* Fix `GL_KHR_compute_shader_derivatives` regressions on shaders using the `GL_NV` variant
* Update compute shader derivative rules to allow texture operations with implicit derivatives without extensions, falling back to LoD 0

### New Extensions

* Implement `GL_EXT_ocp_microscaling_types`
* Implement `GL_NV_cooperative_matrix_decode_vector`
* Add basic support for `GL_NV_desktop_lowp_mediump`
* Implement `GL_EXT_opacity_micromap_ray_query_mode`

### Bug Fixes

* Fix generated decoration string from `UTF8EncodingKHR` to `UTFEncodingKHR`
* Fix missing SPIR-V extension emission for `float16` derivative functions with `SPV_AMD_gpu_shader_half_float`
* Apply `NoContraction` decoration to `dot()` when `noContraction` is set
* Fix `OpStore` of buffer device address pointer to use 8-byte alignment, consistent with loads
* Fix `RayTracingOpacityMicromapKHR` capability emission to only occur when `gl_RayFlagsForceOpacityMicromap2StateEXT` is actually used, fixing SPIR-V validation failures in ray query shaders outside ray-tracing pipeline stages
* Fix `setInvertY()` to apply Y-inversion to GLSL vertex, geometry, and tessellation-evaluation shaders (previously only affected HLSL)
* Fix `.length()` on arrays of long/cooperative vectors to use `OpArrayLength` instead of a constant component count
* Fix unnecessary cooperative matrix conversions when creating arrays of KHR cooperative matrices
* Add error for cooperative matrix `*=` with bf16/fp8 scalar operands
* Fix out-of-bounds access in `elseSeen` at maximum `#if`/`#ifdef` nesting depth
* Fix out-of-bounds read on empty struct texture template types
* Fix crash in `layoutObjectCheck` when accessing members of an empty block
* Emit an error when HLSL [numthreads] is given more than three arguments instead of crashing the compiler.
* Emit error when attempting to convert a literal string to an incompatible type
* Fix `abortKHR` to preserve the original user-defined string without modification
* Fix out-of-bounds indexing in `TDefaultIoResolverBase::addStage` when a negative `EShLanguage` value is passed

### Other

* Add `--discard-is-terminate` option to emit `OpTerminateInvocation` instead of `OpDemoteToHelperInvocation` for GLSL `discard` when targeting SPIR-V 1.6+
* Add REUSE license compliance infrastructure

Fixed at e6ee5e64b2.