From 724ea71cf97e4887809093c7fc75b7bfe34506f4 Mon Sep 17 00:00:00 2001
From: Ruben Ortlam <rortlam@redhat.com>
Date: Mon, 16 Mar 2026 10:45:49 +0100
Subject: [PATCH] vulkan: fix flash attention dot product precision
 (llama/20589)

---
 ggml/src/ggml-vulkan/vulkan-shaders/flash_attn.comp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/ggml/src/ggml-vulkan/vulkan-shaders/flash_attn.comp b/ggml/src/ggml-vulkan/vulkan-shaders/flash_attn.comp
index ec48f5b1..11b7dce8 100644
--- a/ggml/src/ggml-vulkan/vulkan-shaders/flash_attn.comp
+++ b/ggml/src/ggml-vulkan/vulkan-shaders/flash_attn.comp
@@ -245,7 +245,7 @@ void main() {
 #endif
                     }
                     [[unroll]] for (uint32_t r = 0; r < rows_per_thread; ++r) {
-                        Sf[r][c] += ACC_TYPE(dot(Q_cache[r], K_Tf));
+                        Sf[r][c] += dot(ACC_TYPEV4(Q_cache[r]), ACC_TYPEV4(K_Tf));
                     }
                 }
             }
@@ -270,7 +270,7 @@ void main() {
 #endif
                     }
                     [[unroll]] for (uint32_t r = 0; r < rows_per_thread; ++r) {
-                        Sf[r][c] += ACC_TYPE(dot(Qf[tile_row(r) * qf_stride + d * D_split + d_tid], K_Tf));
+                        Sf[r][c] += dot(ACC_TYPEV4(Qf[tile_row(r) * qf_stride + d * D_split + d_tid]), ACC_TYPEV4(K_Tf));
                     }
                 }
             }