metal : optimize Metal Tensor API usage for GGML_OP_MUL_MAT (#20962)

* Optimize Metal Tensor API usage for matmul2d

Separates the Metal Tensor API (matmul2d) path in kernel_mul_mm into its own standalone kernel, gated by GGML_METAL_HAS_TENSOR.

The legacy simdgroup_matrix kernel is preserved under #else.

Previously both paths were interleaved via #ifdef blocks within a single kernel, forcing the tensor path to share the legacy kernel's data layout and threadgroup memory scheme. Splitting the kernel enabled memory and dispatch optimizations that weren't possible when the two paths shared code structure.

* cont : cleanup

* cont : cleanup

* cont : cleanup

---------

Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>
This commit is contained in:
Developer-Ecosystem-Engineering
2026-04-25 15:14:28 +03:00
committed by GitHub
co-authored by Georgi Gerganov
parent 9d34231bb8
commit d1649047a3
6 changed files with 189 additions and 109 deletions
+23 -3
View File
@@ -677,7 +677,15 @@ ggml_metal_pipeline_with_params ggml_metal_library_get_pipeline_mul_mm(ggml_meta
const ggml_type tsrc1 = op->src[1]->type;
const bool bc_inp = op->src[0]->ne[0] % 32 != 0;
const bool bc_out = op->ne[0] % 64 != 0 || op->ne[1] % 32 != 0;
constexpr int NRA = SZ_SIMDGROUP * N_MM_BLOCK_Y * N_MM_SIMD_GROUP_Y;
constexpr int NRB = SZ_SIMDGROUP * N_MM_BLOCK_X * N_MM_SIMD_GROUP_X;
const bool has_tensor = ggml_metal_device_get_props(ggml_metal_library_get_device(lib))->has_tensor;
const bool bc_out = has_tensor
? (op->ne[0] % NRA != 0 || op->ne[1] % NRB != 0)
: (op->ne[0] % 64 != 0 || op->ne[1] % 32 != 0);
snprintf(base, 256, "kernel_mul_mm_%s_%s", ggml_type_name(tsrc0), ggml_type_name(tsrc1));
snprintf(name, 256, "%s_bci=%d_bco=%d", base, bc_inp, bc_out);
@@ -694,8 +702,20 @@ ggml_metal_pipeline_with_params ggml_metal_library_get_pipeline_mul_mm(ggml_meta
ggml_metal_cv_free(cv);
}
// when the output size is not multiple of 64x32, we need extra smem to prevent out-of-bounds writes
res.smem = bc_out ? 8192 : 4096 + 2048;
if (has_tensor) {
res.nr0 = NRA;
res.nr1 = NRB;
const size_t smem_a = NRA * N_MM_NK_TOTAL * sizeof(ggml_fp16_t);
res.smem = smem_a;
} else {
res.nr0 = 64;
res.nr1 = 32;
res.smem = bc_out ? 8192 : (4096 + 2048);
}
res.nsg = N_MM_SIMD_GROUP_X * N_MM_SIMD_GROUP_Y;
return res;
}