ggml : guard against sumq2 being 0 in IQ4_NL (#20460)

diff --git a/ggml/src/ggml-quants.c b/ggml/src/ggml-quants.c
index cdaded865b16a5949f13fefe0587668e15afc730..48695a61ea3360bec9b0a1de74c80c3c305494b0 100644 (file)
--- a/ggml/src/ggml-quants.c
+++ b/ggml/src/ggml-quants.c
@@ -4767,7 +4767,7 @@ static void quantize_row_iq4_nl_impl(const int super_block_size, const int block
             sumqx += w*q*xb[j];
             sumq2 += w*q*q;
         }
-        d = sumqx/sumq2;
+        d = sumq2 > 0 ? sumqx/sumq2 : 0.f;
         float best = d*sumqx;
         for (int itry = -ntry; itry <= ntry; ++itry) {
             id = (itry + values[0])/max;