vulkan: fix matmul pipeline selection for small n values

 Change mul_mat and mul_mat_id pipeline selection heuristic to prevent
 Intel Arc GPU hangs.

The previous logic would select the small pipeline (mul_mat_id_s) when
one dimension was small, causing hangs on Intel Arc when, e.g. m=512
and n=23 as it happens with IBM Granite 4.

Signed-off-by: Giuseppe Scrivano <[email protected]>

Author: giuseppe

ggml/src/ggml-vulkan/ggml-vulkan.cpp

@@ -5826,10 +5826,10 @@ static vk_pipeline ggml_vk_guess_matmul_pipeline(ggml_backend_vk_context * ctx,
         return aligned ? mmp->a_s : mmp->s;
     }
 
-    if ((ctx->device->mul_mat_s[src0_type] && (m <= 32 || n <= 32)) || (!ctx->device->mul_mat_m[src0_type] && !ctx->device->mul_mat_l[src0_type])) {
+    if ((ctx->device->mul_mat_s[src0_type] && (m * n <= 32 * 32)) || (!ctx->device->mul_mat_m[src0_type] && !ctx->device->mul_mat_l[src0_type])) {
         return aligned ? mmp->a_s : mmp->s;
     }
-    if ((ctx->device->mul_mat_m[src0_type] && (m <= 64 || n <= 64)) || !ctx->device->mul_mat_l[src0_type]) {
+    if ((ctx->device->mul_mat_m[src0_type] && (m * n <= 64 * 64)) || !ctx->device->mul_mat_l[src0_type]) {
         return aligned ? mmp->a_m : mmp->m;
     }
     return aligned ? mmp->a_l : mmp->l;
@@ -5892,10 +5892,10 @@ static vk_pipeline ggml_vk_guess_matmul_id_pipeline(ggml_backend_vk_context * ct
         return aligned ? mmp->a_s : mmp->s;
     }
 
-    if ((ctx->device->mul_mat_id_s[src0_type] && (m <= 32 || n <= 32)) || (!ctx->device->mul_mat_id_m[src0_type] && !ctx->device->mul_mat_id_l[src0_type])) {
+    if ((ctx->device->mul_mat_id_s[src0_type] && (m * n <= 32 * 32)) || (!ctx->device->mul_mat_id_m[src0_type] && !ctx->device->mul_mat_id_l[src0_type])) {
         return aligned ? mmp->a_s : mmp->s;
     }
-    if ((ctx->device->mul_mat_id_m[src0_type] && (m <= 64 || n <= 64)) || !ctx->device->mul_mat_id_l[src0_type]) {
+    if ((ctx->device->mul_mat_id_m[src0_type] && (m * n <= 64 * 64)) || !ctx->device->mul_mat_id_l[src0_type]) {
         return aligned ? mmp->a_m : mmp->m;
     }
     return aligned ? mmp->a_l : mmp->l;