Direct V73 W4A8 contraction and INT32 readback
Date: 2026-09-24 Target: Samsung Galaxy S23, SM8550, Hexagon V73 Execution boundary: unsigned CDSP user process domain
Artifact
- Producer: PowerShell named-instruction emitter
- Library:
libkokoro_hmx_matrix_skel.so - SHA-256:
A5A2C178247236DC5EFE50179586C631F9392636A9E53DD8932BD8A059629577 - File size: 8,384 bytes
- Code size: 2,556 bytes
- Dynamic imports: 0
- Relocations: 0
The integer path performs the HMX contraction, four biased accumulator-plane extracts, and a sixteen-block HVX byte-plane interleave directly in the emitted library. Qualcomm HexKL is used by the diagnostic helper only to produce an independent expected output in the same process.
Encoder gate
The pinned Qualcomm LLVM 19.0.04 assembler was the independent byte oracle for 2,713 legal instruction and packet cases. All 19,852 emitted code bytes matched. Eighteen invalid operand cases were rejected.
Device gate
Dense integer inputs have an expected result of 32 in every INT32 lane.
| Mode | Direct output SHA-256 | Qualcomm oracle SHA-256 | Result |
|---|---|---|---|
| W8A8 | E649DCF992752D6621F670C1ED2574E5A7262637F6AEC668ACE146CE9531DB4D |
same | exact |
| W4A8 | E649DCF992752D6621F670C1ED2574E5A7262637F6AEC668ACE146CE9531DB4D |
same | exact |
The W4A8 path reached its final stage marker, returned 2,048 nonzero bytes in the 8,192-byte INT32 result, and passed the exact semantic gate.
Thirty-one additional warm invocations reused the resident operands:
| Mode | Compute ticks min / median / p95 / max | Median compute | Median host invoke |
|---|---|---|---|
| FP16 | 3 / 4 / 4 / 23 | 0.208 microseconds | 0.237 ms |
| W8A8 | 47 / 48 / 50 / 69 | 2.50 microseconds | 0.245 ms |
| W4A8 | 48 / 48 / 50 / 65 | 2.50 microseconds | 0.247 ms |
The integer measurement includes the contraction, all four accumulator-plane extracts, and the HVX interleave. W8A8 and W4A8 share the same integer readback cost. These numbers characterize this emitted kernel; the LLVM comparison remains a separate gate.
The complete probe passed and restored the application startup files. The raw device result is outside the repository at:
a local build directory
Remaining performance gate
Run repeated resident W4A8 tiles in one invocation against an LLVM-compiled implementation with identical inputs, output layout, lock scope, and timing boundaries. FastRPC setup and transport are reported separately.