ggml-org/llama.cpp b11408

on GitHub

ggml-cpu : add Q8_0 IME1 matrix kernel for SpacemiT X60 (#28479)

• ggml-cpu : add Q8_0 IME1 matrix kernel for SpacemiT X60

On the SpacemiT X60, IME matrix acceleration only covered Q4_0/Q4_1/Q4_K.
Q8_0 had no IME1 kernel, and since the SpacemiT build sets
GGML_CPU_REPACK=OFF there was no repack path compiled in either, so Q8_0
had no accelerated path at all and ran roughly ten times slower than
Q4_0 for prefill on the same board.

• add make_block_q8_0x16 and the Q8_0 repack entry: interleave the
  weights into the 16-column layout the IME1 vmadot sequence expects
• add ime1::gemm_kernel_i8i8, an int8 x int8 IME1 kernel with a
  single-row and a 4-row A path; the 4-row path loads each B panel once
  and reuses it across 4 rows of A
• add quantize_a_4row_i8 for the 4-row activation quantization
• wire both into forward_mul_mat and the repack factory for Q8_0
• docs: mark Q8_0 as supported on X60

Correctness was checked against a quant-exact integer reference for
K = 32 up to 4096, with a max relative error of about 1e-6, and by
checking that generation stays coherent across several prompts.

Tested on Milk-V Jupiter (SpacemiT X60), Bianbu 2.1.1, gcc 14.2, with
Qwen2.5-0.5B-Instruct Q8_0. llama-bench -t 4 under taskset -c 0-3, 5
repetitions on an idle board: pp128 goes from 10.70 to 93.87 t/s. Q4_0
is unchanged at 106.40 -> 107.51 t/s, as expected since this does not
touch that path.

• ggml-cpu : move q8_0_16x32 decl to IME1 section

• ggml-cpu : align q8_0 IME1 kernel assignments