mtmd: fix Gemma 4 unified FPE (#24088)

diff --git a/tools/mtmd/clip.cpp b/tools/mtmd/clip.cpp
index 1abde5fb5f3789c5cf1075fc8ffba5f98e6b2c50..2008198150dd9abd1e49c339dd82f6c40ddfc8c7 100644 (file)
--- a/tools/mtmd/clip.cpp
+++ b/tools/mtmd/clip.cpp
@@ -247,11 +247,11 @@ clip_graph::clip_graph(clip_ctx * ctx, const clip_image_f32 & img) :
         n_embd(hparams.n_embd),
         n_head(hparams.n_head),
         n_head_kv(hparams.n_head_kv),
-        d_head(n_embd / n_head),
+        d_head(n_head > 0 ? n_embd / n_head : 0),
         n_layer(hparams.n_layer),
         n_mmproj_embd(clip_n_mmproj_embd(ctx)),
         eps(hparams.eps),
-        kq_scale(1.0f / sqrtf((float)d_head)),
+        kq_scale(d_head > 0 ? 1.0f / sqrtf((float)d_head) : 0.0f),
         flash_attn_type(ctx->flash_attn_type) {
     struct ggml_init_params params = {
         /*.mem_size   =*/ ctx->buf_compute_meta.size(),