ggml-org/llama.cpp b11292

on GitHub

cpu: accept BF16 in src1 of mul_mat (#28937)

• cpu: accept BF16 in src1 of mul_mat

ggml_conv_1d_dw builds its im2col in F32 when the kernel is BF16, then
calls ggml_mul_mat(im2col, kernel), which puts F32 in src0 and BF16 in
src1. The CPU backend refused that combination, so it was reported as
unsupported on every backend and never compared against anything.

Widen BF16 into the F32 work buffer, next to the existing packing of F32
into vec_dot_type. This is the arithmetic the Metal mat vec kernel
already uses, both operands promoted to float and accumulated in float,
so the two agree exactly rather than approximately.

Cover it with a conv_1d_dw test over F32, F16 and BF16 kernels, plus
three mul_mat cases with BF16 in src1.

• vulkan: reject BF16 in src1 of mul_mat unless src0 is BF16

supports_op only checked the src1 type for non contiguous tensors, so
a contiguous BF16 src1 was accepted and the pipeline lookup asserted.
The only BF16 src1 path is the BF16 x BF16 multiply, every other src0
type now reports the op as unsupported and the scheduler keeps it on
the CPU.

The BF16 kernel case of the conv_1d_dw test needs the f32 x bf16
mat vec variants of the Metal backend, which land separately.