Commit 0f701c882 for llama.cpp

commit 0f701c88298606b41a13268a027e97c877ff63ca
Author: Alex Morgan <36094800+amitmi704@users.noreply.github.com>
Date:   Mon Oct 12 09:19:20 2026 -0500

    vulkan: pack FMA for f16 accumulation, no dot product op (#29877)

    * vulkan: pack FMA for f16 accumulation, no dot product op

    * vulkan: dot_product packs two rows per f16 FMA

    * vulkan: rename dot_product to dot_product_v2

diff --git a/ggml/src/ggml-vulkan/vulkan-shaders/dot_product_funcs.glsl b/ggml/src/ggml-vulkan/vulkan-shaders/dot_product_funcs.glsl
index c474bfe09..d7a9804ba 100644
--- a/ggml/src/ggml-vulkan/vulkan-shaders/dot_product_funcs.glsl
+++ b/ggml/src/ggml-vulkan/vulkan-shaders/dot_product_funcs.glsl
@@ -13,6 +13,14 @@ ACC_TYPE dot_product(f16vec2 a, f16vec2 b, ACC_TYPE acc) {
     return ACC_TYPE(v_dot2_f32_f16(a, b, float(acc)));
 }

+ACC_TYPEV2 dot_product_v2(f16vec4 a0, f16vec4 a1, f16vec4 b, ACC_TYPEV2 acc) {
+    return ACC_TYPEV2(dot_product(a0, b, acc.x), dot_product(a1, b, acc.y));
+}
+
+ACC_TYPEV2 dot_product_v2(f16vec2 a0, f16vec2 a1, f16vec2 b, ACC_TYPEV2 acc) {
+    return ACC_TYPEV2(dot_product(a0, b, acc.x), dot_product(a1, b, acc.y));
+}
+
 #else

 ACC_TYPE dot_product(FLOAT_TYPEV4 a, FLOAT_TYPEV4 b, ACC_TYPE acc) {
@@ -24,4 +32,27 @@ ACC_TYPE dot_product(FLOAT_TYPEV2 a, FLOAT_TYPEV2 b, ACC_TYPE acc) {
     return fma(ACC_TYPE(a.x), ACC_TYPE(b.x), fma(ACC_TYPE(a.y), ACC_TYPE(b.y), acc));
 }

+#if defined(ACC_F16)
+// two rows at once, so f16 accumulation can use packed fma
+ACC_TYPEV2 dot_product_v2(FLOAT_TYPEV4 a0, FLOAT_TYPEV4 a1, FLOAT_TYPEV4 b, ACC_TYPEV2 acc) {
+    acc = fma(ACC_TYPEV2(a0.w, a1.w), ACC_TYPEV2(b.w), acc);
+    acc = fma(ACC_TYPEV2(a0.z, a1.z), ACC_TYPEV2(b.z), acc);
+    acc = fma(ACC_TYPEV2(a0.y, a1.y), ACC_TYPEV2(b.y), acc);
+    return fma(ACC_TYPEV2(a0.x, a1.x), ACC_TYPEV2(b.x), acc);
+}
+
+ACC_TYPEV2 dot_product_v2(FLOAT_TYPEV2 a0, FLOAT_TYPEV2 a1, FLOAT_TYPEV2 b, ACC_TYPEV2 acc) {
+    acc = fma(ACC_TYPEV2(a0.y, a1.y), ACC_TYPEV2(b.y), acc);
+    return fma(ACC_TYPEV2(a0.x, a1.x), ACC_TYPEV2(b.x), acc);
+}
+#else
+ACC_TYPEV2 dot_product_v2(FLOAT_TYPEV4 a0, FLOAT_TYPEV4 a1, FLOAT_TYPEV4 b, ACC_TYPEV2 acc) {
+    return ACC_TYPEV2(dot_product(a0, b, acc.x), dot_product(a1, b, acc.y));
+}
+
+ACC_TYPEV2 dot_product_v2(FLOAT_TYPEV2 a0, FLOAT_TYPEV2 a1, FLOAT_TYPEV2 b, ACC_TYPEV2 acc) {
+    return ACC_TYPEV2(dot_product(a0, b, acc.x), dot_product(a1, b, acc.y));
+}
+#endif
+
 #endif
diff --git a/ggml/src/ggml-vulkan/vulkan-shaders/mul_mm.comp b/ggml/src/ggml-vulkan/vulkan-shaders/mul_mm.comp
index 9f31ef126..19d37870b 100644
--- a/ggml/src/ggml-vulkan/vulkan-shaders/mul_mm.comp
+++ b/ggml/src/ggml-vulkan/vulkan-shaders/mul_mm.comp
@@ -407,8 +407,7 @@ void main() {
                         [[unroll]] for (uint cr = 0; cr < TM / 2; cr++) {
                             // [WNITER][TN][WMITER][TM / 2] -> [wsic][cc][wsir][cr]
                             const uint sums_idx = (wsic * TN + cc) * WMITER * (TM / 2) + wsir * (TM / 2) + cr;
-                            sums[sums_idx].x = dot_product(cache_a[wsir * TM + 2 * cr    ], cache_b, sums[sums_idx].x);
-                            sums[sums_idx].y = dot_product(cache_a[wsir * TM + 2 * cr + 1], cache_b, sums[sums_idx].y);
+                            sums[sums_idx] = dot_product_v2(cache_a[wsir * TM + 2 * cr], cache_a[wsir * TM + 2 * cr + 1], cache_b, sums[sums_idx]);
                         }
                     }
                 }
diff --git a/ggml/src/ggml-vulkan/vulkan-shaders/vulkan-shaders-gen.cpp b/ggml/src/ggml-vulkan/vulkan-shaders/vulkan-shaders-gen.cpp
index 7597b3d33..94417f62b 100644
--- a/ggml/src/ggml-vulkan/vulkan-shaders/vulkan-shaders-gen.cpp
+++ b/ggml/src/ggml-vulkan/vulkan-shaders/vulkan-shaders-gen.cpp
@@ -485,6 +485,7 @@ void matmul_shaders(bool fp16, MatMulIdType matmul_id_type, bool coopmat, bool c
     base_dict["ACC_TYPE_VEC4"] = f16acc ? "f16vec4"   : "vec4";
     if (f16acc) {
         base_dict["ACC_TYPE_MAX"] = "float16_t(65504.0)";
+        base_dict["ACC_F16"] = "1";
     }

     if (coopmat) {