wai-quantum 0.6.1: the CUDA tensor-core kernel and the Metal member #275

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dcharlot merged 3 commits from wai/quantum-tensor-cores into main 2026-10-16 09:45:04 -04:00

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2026-10-16

Transaction Science

Merge remote-tracking branch 'origin/main' into wai/quantum-metal ...

# Conflicts:
#	wai/CHANGELOG.md

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2026-10-16 09:44:28 -04:00

Transaction Science

wai-quantum: the Metal member, with a SIMD-group matrix kernel ...

quantum_fabric_metal (opt-in, macOS): the gate on the platform's GPU
through its own interface, kernels compiled at run time by the operating
system's compiler, the state in a buffer the GPU and the host share, one
serial dispatch per gate in one command buffer.

- lanes64.metal (metal-lanes64/...): the CUDA kernel's exact 64-bit
  integer arithmetic in the Metal shading language.
- matrix_limbs.metal (metal-matrix-limbs8/..., MetalMember::matrix):
  every product formed by the SIMD-group matrix multiply from 8-bit limbs
  in bf16 accumulated in f32; one SIMD group takes eight pairs in fourteen
  8x8 column blocks, each thread joins four products and forms one row.
  GPU family 1007 or later, else MetalError::Unsupported.

Keyed by GPU family number (gpu-msl-<family>). Off macOS the member
builds, finds nothing and says why (uninhabited platform types).

Measured on the M3 Ultra runner's GPU (family 1009): metal_member and
metal_matrix 9/9 each, 66020 probe pairs, all four pinned certificates,
22 qubits, 6 of 6 and 7 of 7 mutants (nine-bit limbs break 297 of 484
edge pairs). On Linux both suites pass over no device. CI:
wai-quantum-metal (macos and linux legs).

Co-Authored-By: Claude Opus 5.5 <[email protected]>

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2026-10-16 04:59:05 -04:00

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wai-quantum 0.6.1: the CUDA member's tensor-core kernel ...

A second CUDA kernel for the same gate (tensor_limbs.cu), for devices of
compute capability 8.0 or later, whose every product is formed on the
tensor cores: each 32-bit value as four 8-bit limbs in bf16, one warp
multiplying sixteen pairs' limbs by the gate's limb weights in fourteen
m16n8k16 steps, accumulated in f32. Every coefficient is an integer below
2^18, so f32 holds every partial sum exactly in any order; the kernel adds
the coefficients, shifted into place, in 64-bit integers and does the rest
of the gate as lanes64.cu does.

CudaMember::tensor gives the same device under the kernel's own
implementation id (cuda-tensor-limbs8/...), probed before it is returned;
a device below 8.0 is CudaError::Unsupported. Seven mutants, one of them
nine-bit limbs, which bf16 does not hold.

Measured on the discrete GPU (sm_89): tests/cuda_tensor.rs 9/9, 66020
probe pairs, all four pinned certificates, circuits to 22 qubits, 7 of 7
mutants; cuda_member 9/9 and cuda_sv 3/3 unchanged. With no CUDA, both
suites pass over no device. CI: a step of wai-quantum-cuda and the absent
leg.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

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2026-10-16 04:21:11 -04:00