llama.cpp

dd4c286f - ggml-cpu : fix soft_max_back wrong output when dst aliases src1 (#27096)

ggml-cpu : fix soft_max_back wrong output when dst aliases src1 (#27096) * ggml-cpu : fix soft_max_back wrong output when dst aliases src1 GGML_OP_SOFT_MAX_BACK is listed in ggml_op_can_inplace, so the graph allocator may assign dst to alias either src0 (dy) or src1 (y). The result was built in several steps: ggml_vec_cpy_f32 (nc, dx, dy); ggml_vec_acc1_f32 (nc, dx, -dot_y_dy); ggml_vec_mul_f32 (nc, dx, dx, y); ggml_vec_scale_f32(nc, dx, scale); When dst aliases src1, the first step overwrites y and the third step then reads the overwritten values, so the output is silently wrong. Aliasing dst with src0 is unaffected. The CUDA kernel completes its reduction before writing and is already safe. Replace the sequence with a single fused loop that reads both sources before writing, which is correct under either aliasing. Add a regression test that marks dy as a graph output so the allocator is forced to alias dst with y, asserts that the alias actually happened, and compares against values computed on the host. * cont : remove comment --------- Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>