sycl : implementation of reordered Q4_0 MMVQ for Intel GPUs (llama/12858)

* sycl : Implemented reorder Q4_0 mmvq

Signed-off-by: Alberto Cabrera <alberto.cabrera@codeplay.com>

* sycl : Fixed mmvq being called when reorder is disabled

* sycl : Improved comments in the quants header

Signed-off-by: Alberto Cabrera <alberto.cabrera@codeplay.com>

* Use static_assert

* safe_div -> ceil_div

* Clarify qi comment

* change the reorder tensor from init to execute OP

* dbg

* Undo changes to test-backend-ops

* Refactor changes on top of q4_0 reorder fix

* Missing Reverts

* Refactored opt_for_reorder logic to simplify code path

* Explicit inlining and unroll

* Renamed mul_mat_algo enum for consistency

---------

Signed-off-by: Alberto Cabrera <alberto.cabrera@codeplay.com>
Co-authored-by: romain.biessy <romain.biessy@codeplay.com>

ggml/src/ggml-sycl/backend.hpp

@@ -14,23 +14,24 @@
 #define GGML_SYCL_BACKEND_HPP
 
 #include "binbcast.hpp"
-#include "concat.hpp"
 #include "common.hpp"
+#include "concat.hpp"
 #include "conv.hpp"
 #include "convert.hpp"
+#include "cpy.hpp"
 #include "dequantize.hpp"
 #include "dmmv.hpp"
+#include "element_wise.hpp"
+#include "gla.hpp"
+#include "im2col.hpp"
 #include "mmq.hpp"
 #include "mmvq.hpp"
-#include "rope.hpp"
 #include "norm.hpp"
+#include "outprod.hpp"
+#include "quants.hpp"
+#include "rope.hpp"
 #include "softmax.hpp"
 #include "tsembd.hpp"
-#include "im2col.hpp"
 #include "wkv.hpp"
-#include "outprod.hpp"
-#include "element_wise.hpp"
-#include "cpy.hpp"
-#include "gla.hpp"
 
 #endif  // GGML_SYCL_BACKEND_HPP

ggml/src/ggml-sycl/common.hpp

@@ -42,6 +42,7 @@ void ggml_sycl_host_free(void* ptr);
 
 extern int g_ggml_sycl_debug;
 extern int g_ggml_sycl_disable_optimize;
+extern int g_ggml_sycl_prioritize_dmmv;
 
 #define GGML_SYCL_DEBUG(...)        \
   do {                              \

ggml/src/ggml-sycl/ggml-sycl.cpp

@@ -49,6 +49,7 @@ static bool g_sycl_loaded = false;
 int g_ggml_sycl_debug = 0;
 int g_ggml_sycl_disable_optimize = 0;
 int g_ggml_sycl_disable_graph = 0;
+int g_ggml_sycl_prioritize_dmmv = 0;
 
 static ggml_sycl_device_info ggml_sycl_init() {
     ggml_sycl_device_info info = {};
@@ -195,11 +196,13 @@ static void ggml_check_sycl() try {
         g_ggml_sycl_debug = get_sycl_env("GGML_SYCL_DEBUG", 0);
         g_ggml_sycl_disable_optimize= get_sycl_env("GGML_SYCL_DISABLE_OPT", 1);
         g_ggml_sycl_disable_graph = get_sycl_env("GGML_SYCL_DISABLE_GRAPH", 1);
+        g_ggml_sycl_prioritize_dmmv = get_sycl_env("GGML_SYCL_PRIORITIZE_DMMV", 0);
         GGML_SYCL_DEBUG("[SYCL] call ggml_check_sycl\n");
         GGML_LOG_INFO("Running with Environment Variables:\n");
         GGML_LOG_INFO("  GGML_SYCL_DEBUG: %d\n", g_ggml_sycl_debug);
         GGML_LOG_INFO("  GGML_SYCL_DISABLE_OPT: %d\n", g_ggml_sycl_disable_optimize);
         GGML_LOG_INFO("  GGML_SYCL_DISABLE_GRAPH: %d\n", g_ggml_sycl_disable_graph);
+        GGML_LOG_INFO("  GGML_SYCL_PRIORITIZE_DMMV: %d\n", g_ggml_sycl_prioritize_dmmv);
         GGML_LOG_INFO("Build with Macros:\n");
 #if defined(GGML_SYCL_FORCE_MMQ)
         GGML_LOG_INFO("  GGML_SYCL_FORCE_MMQ: yes\n");
@@ -2822,12 +2825,45 @@ static void ggml_sycl_mul_mat_batched_sycl(ggml_backend_sycl_context & ctx, cons
     std::exit(1);
 }
 
+enum class mul_mat_algo {
+    DMMV         = 0,
+    MMVQ         = 1,
+    MUL_MAT_SYCL = 2,
+};
+
 inline bool ggml_sycl_supports_mmq(enum ggml_type type) {
     // TODO: accuracy issues in MMQ
     GGML_UNUSED(type);
     return false;
 }
 
+inline bool ggml_sycl_supports_reorder_mul_mat_sycl(enum ggml_type type) {
+    switch (type) {
+        case GGML_TYPE_Q4_0:
+            return true;
+        default:
+            return false;
+    }
+}
+
+inline bool ggml_sycl_supports_reorder_dmmv(enum ggml_type type) {
+    switch (type) {
+        case GGML_TYPE_Q4_0:
+            return true;
+        default:
+            return false;
+    }
+}
+
+inline bool ggml_sycl_supports_reorder_mmvq(enum ggml_type type) {
+    switch (type) {
+        case GGML_TYPE_Q4_0:
+            return true;
+        default:
+            return false;
+    }
+}
+
 static bool ggml_sycl_supports_dmmv(enum ggml_type type) {
     switch (type) {
         case GGML_TYPE_Q4_0:
@@ -2856,7 +2892,7 @@ static void reorder_qw(char *data_device, const int ncols, const int nrows,
     GGML_ASSERT((size % sizeof(block_q4_0) == 0));
     GGML_ASSERT((offset % sizeof(block_q4_0) == 0));
     int offset_blks = offset / sizeof(block_q4_0);
-    auto qs_ptr = (uint8_t*)data_device + offset_blks * QK4_0 / 2;;
+    auto qs_ptr = (uint8_t*)data_device + offset_blks * QK4_0 / 2;
     auto d_ptr = (sycl::half*)(qs_ptr + ncols * nrows / 2) + offset_blks;
 
     stream->parallel_for(
@@ -2884,25 +2920,44 @@ static void reorder_qw(const ggml_tensor * src0, dpct::queue_ptr stream) {
     reorder_qw(data_device, ncols, nrows, size, 0, stream);
 }
 
-/*
+static bool should_reorder_tensor(ggml_backend_sycl_context& ctx, const ggml_tensor * dst) {
-* This function could be called when the OP (mul_mat) function support reorder optimizition.
+    return !g_ggml_sycl_disable_optimize && //allow optimize, controlled by $GGML_SYCL_DISABLE_OPT
-*/
+            ctx.opt_feature.reorder &&      //allow this device due to good perf, skip the devices with bad perf.
-static void opt_for_reorder(ggml_backend_sycl_context * ctx, const ggml_tensor * src0, const ggml_tensor * src1,
-    ggml_tensor * dst) {
-    if (!g_ggml_sycl_disable_optimize && //allow optimize, controlled by $GGML_SYCL_DISABLE_OPT
-        ctx->opt_feature.reorder &&      //allow this device due to good perf, skip the devices with bad perf.
             dst->op == GGML_OP_MUL_MAT &&   //limit to some supported cases of Q4_0, to do for more cases.
-        src0->type == GGML_TYPE_Q4_0 &&
+            dst->src[1]->ne[2]==1 && dst->src[1]->ne[3]==1;
-        src1->ne[2]==1 && src1->ne[3]==1) {
+}
 
-        ggml_tensor_extra_gpu* extra = (ggml_tensor_extra_gpu*)src0->extra;
+static void opt_for_reorder(ggml_backend_sycl_context * ctx, const ggml_tensor * src0, const ggml_tensor * /* src1 */,
-        if (!extra) return; //only happen in CI/UT permute case.
+                            ggml_tensor * dst, mul_mat_algo mm_algorithm) {
+    if (!should_reorder_tensor(*ctx, dst)) {
+        return;
+    }
 
-        if (extra->optimized_feature.reorder) return; //skip the tensor which is handled for reorder.
+    ggml_tensor_extra_gpu * extra = static_cast<ggml_tensor_extra_gpu *>(src0->extra);
+    if (!extra || extra->optimized_feature.reorder) {
+        return;  // Skip permutations and already reordered tensors
+    }
+
+    switch (mm_algorithm) {
+        case mul_mat_algo::DMMV:
+            if (!ggml_sycl_supports_reorder_dmmv(src0->type)) {
+                return;
+            }
+            break;
+        case mul_mat_algo::MMVQ:
+            if (!ggml_sycl_supports_reorder_mmvq(src0->type)) {
+                return;
+            }
+            break;
+        case mul_mat_algo::MUL_MAT_SYCL:
+            if (!ggml_sycl_supports_reorder_mul_mat_sycl(src0->type)) {
+                return;
+            }
+            break;
+    }
 
     reorder_qw(src0, ctx->stream());
-        extra->optimized_feature.reorder = true; //used to decode/dequan in next steps.
+    extra->optimized_feature.reorder = true;  // Used to decode/dequan in next steps and avoid re-reordering
-    }
 }
 
 static void ggml_sycl_mul_mat(ggml_backend_sycl_context & ctx, const ggml_tensor * src0, const ggml_tensor * src1, ggml_tensor * dst) {
@@ -2911,7 +2966,8 @@ static void ggml_sycl_mul_mat(ggml_backend_sycl_context & ctx, const ggml_tensor
     int64_t min_compute_capability = INT_MAX;
 
     if (split) {
-        ggml_backend_sycl_split_buffer_type_context * buft_ctx = (ggml_backend_sycl_split_buffer_type_context *) src0->buffer->buft->context;
+        ggml_backend_sycl_split_buffer_type_context * buft_ctx =
+            (ggml_backend_sycl_split_buffer_type_context *) src0->buffer->buft->context;
         auto & tensor_split = buft_ctx->tensor_split;
         for (int id = 0; id < ggml_sycl_info().device_count; ++id) {
             // skip devices that are not going to do any work:
@@ -2946,9 +3002,15 @@ static void ggml_sycl_mul_mat(ggml_backend_sycl_context & ctx, const ggml_tensor
     use_mul_mat_q = use_mul_mat_q && (src1->ne[1] <= MMQ_MAX_BATCH_SIZE);
 #endif // SYCL_USE_XMX
 
+
     // mmvq path is faster in the CUDA backend.
-    if (ctx.stream()->get_backend() == sycl::backend::ext_oneapi_cuda)
+    if (!g_ggml_sycl_prioritize_dmmv && (ctx.stream()->get_backend() == sycl::backend::ext_oneapi_cuda
+        // Dispatch becomes obscure with the reorder, MMVQ when the reorder optimization
+        // is enabled takes precedence over DMMV, the current if-else implementation
+        // requires disabling DMMV if both conditions are met
+        || (should_reorder_tensor(ctx, dst) && ggml_sycl_supports_reorder_mmvq(src0->type)))) {
         use_dequantize_mul_mat_vec = use_dequantize_mul_mat_vec && !use_mul_mat_vec_q;
+    }
 
     if (!split && src0->type == GGML_TYPE_F16 && ggml_is_permuted(src0) && ggml_is_permuted(src1) && src1->ne[1] == 1) {
         // TODO: Refactor and cleanup of mul mat dispatching.
@@ -2967,17 +3029,23 @@ static void ggml_sycl_mul_mat(ggml_backend_sycl_context & ctx, const ggml_tensor
         // KQ + KQV multi-batch
         ggml_sycl_mul_mat_batched_sycl(ctx, src0, src1, dst);
     } else if (use_dequantize_mul_mat_vec) {
-        opt_for_reorder(&ctx, src0, src1, dst); //the OP function in this branch support reorder.
+        constexpr bool convert_src1_to_q8_1 = false;
-        ggml_sycl_op_mul_mat(ctx, src0, src1, dst, ggml_sycl_op_dequantize_mul_mat_vec, false);
+        opt_for_reorder(&ctx, src0, src1, dst, mul_mat_algo::DMMV);
-        // save_tensor_txt("1/dst_1.txt", (float*) dst->data, src0->ne[1], sizeof(float), ctx.stream());
+        ggml_sycl_op_mul_mat(ctx, src0, src1, dst, ggml_sycl_op_dequantize_mul_mat_vec, convert_src1_to_q8_1);
     } else if (use_mul_mat_vec_q) {
-        ggml_sycl_op_mul_mat(ctx, src0, src1, dst, ggml_sycl_op_mul_mat_vec_q, true);
+        constexpr bool convert_src1_to_q8_1 = true;
+        opt_for_reorder(&ctx, src0, src1, dst, mul_mat_algo::MMVQ);
+        ggml_sycl_op_mul_mat(ctx, src0, src1, dst, ggml_sycl_op_mul_mat_vec_q, convert_src1_to_q8_1);
     } else if (use_mul_mat_q) {
-        ggml_sycl_op_mul_mat(ctx, src0, src1, dst, ggml_sycl_op_mul_mat_q, true);
+        constexpr bool convert_src1_to_q8_1 = true;
+        ggml_sycl_op_mul_mat(ctx, src0, src1, dst, ggml_sycl_op_mul_mat_q, convert_src1_to_q8_1);
     } else {
-        opt_for_reorder(&ctx, src0, src1, dst); //the OP function in this branch support reorder.
+        constexpr bool convert_src1_to_q8_1 = false;
-        ggml_sycl_op_mul_mat(ctx, src0, src1, dst, ggml_sycl_op_mul_mat_sycl, false);
+        // MUL_MAT_SYCL supports reorder
+        opt_for_reorder(&ctx, src0, src1, dst, mul_mat_algo::MUL_MAT_SYCL);
+        ggml_sycl_op_mul_mat(ctx, src0, src1, dst, ggml_sycl_op_mul_mat_sycl, convert_src1_to_q8_1);
     }
+    GGML_SYCL_DEBUG("call %s done\n", __func__);
 }
 
 

ggml/src/ggml-sycl/mmvq.cpp

@@ -1,6 +1,60 @@
 #include "mmvq.hpp"
+
+#include "ggml.h"
+#include "common.hpp"
+#include "quants.hpp"
 #include "vecdotq.hpp"
-#include <cassert>
+
+template <typename reorder_vec_dot_q_sycl>
+static void mul_mat_vec_q_reorder(const void * __restrict__ vx, const void * __restrict__ vy, float * __restrict__ dst,
+                                  const int ncols, const int nrows, const sycl::nd_item<3> & nd_item) {
+    using block_type   = ggml_sycl_reordered::block_q_t<reorder_vec_dot_q_sycl::gtype>;
+    using block_traits = typename block_type::traits;
+
+    const auto sg           = nd_item.get_sub_group();
+    const int  sg_range     = sg.get_group_linear_range();
+    const int  workgroup_id = nd_item.get_group_linear_id();
+    const int  sg_id        = sg.get_group_linear_id();
+    const int  row          = workgroup_id * sg_range + sg_id;
+
+    if (row >= nrows) {
+        return;
+    }
+
+    const int     blocks_per_row              = ncols / block_traits::qk;
+    constexpr int blocks_per_subgroup         = ceil_div(block_traits::vdr_mmvq * WARP_SIZE, block_traits::qi);
+    constexpr int block_elements_per_subgroup = block_traits::qi / block_traits::vdr_mmvq;
+
+    static_assert(blocks_per_subgroup > 0);
+    static_assert(block_elements_per_subgroup > 0);
+
+    const block_q8_1 * y = (const block_q8_1 *) vy;
+
+    float partial_sum = 0.0f;
+    for (int i = sg.get_local_linear_id() / block_elements_per_subgroup; i < blocks_per_row; i += blocks_per_subgroup) {
+        const int ibx       = row * blocks_per_row + i;  // x block index
+        // TODO: Generalize offsets, right now only works for quantizations that don't split high and low bits
+        const int bx_offset = block_type::get_block_offset(ibx);
+        const int d_offset  = block_type::get_d_offset(nrows, ncols, ibx);
+
+        // Y block index that aligns with ibx
+        const int iby = i * block_type::block_to_q8_1_ratio();
+
+#pragma unroll
+        for (int elem = 0; elem < block_elements_per_subgroup; elem += WARP_SIZE) {
+            // x block quant index when casting the quants to int
+            const int iqs = elem + block_traits::vdr_mmvq * (sg.get_local_linear_id() % block_elements_per_subgroup);
+
+            partial_sum += reorder_vec_dot_q_sycl()(vx, bx_offset, d_offset, &y[iby], iqs);
+        }
+    }
+
+    auto sum = sycl::reduce_over_group(nd_item.get_sub_group(), partial_sum, std::plus<>());
+
+    if (sg.leader()) {
+        dst[row] = sum;
+    }
+}
 
 template <int qk, int qi, typename block_q_t, int vdr, vec_dot_q_sycl_t vec_dot_q_sycl>
 static void mul_mat_vec_q(const void * __restrict__ vx, const void * __restrict__ vy, float * __restrict__ dst,
@@ -480,24 +534,37 @@ static void mul_mat_vec_q_iq4_xs_q8_1(const void *__restrict__ vx,
     }
 }
 
-static void mul_mat_vec_q4_0_q8_1_sycl(const void *vx, const void *vy,
+static void reorder_mul_mat_vec_q4_0_q8_1_sycl(const void * vx, const void * vy, float * dst, const int ncols,
-                                       float *dst, const int ncols,
+                                                    const int nrows, dpct::queue_ptr stream) {
-                                       const int nrows,
+    GGML_ASSERT(ncols % QK4_0 == 0);
+    const int        block_num_y   = ceil_div(nrows, GGML_SYCL_MMV_Y);
+    constexpr size_t num_subgroups = 16;
+    GGML_ASSERT(block_num_y % num_subgroups == 0);
+
+    const sycl::range<3> global_size(1, GGML_SYCL_MMV_Y, (block_num_y * WARP_SIZE));
+    const sycl::range<3> workgroup_size(1, GGML_SYCL_MMV_Y, num_subgroups * WARP_SIZE);
+
+    stream->submit([&](sycl::handler & cgh) {
+        cgh.parallel_for(sycl::nd_range<3>(global_size, workgroup_size),
+                         [=](sycl::nd_item<3> nd_item) [[sycl::reqd_sub_group_size(WARP_SIZE)]] {
+                             mul_mat_vec_q_reorder<reorder_vec_dot_q_sycl<GGML_TYPE_Q4_0>>(vx, vy, dst, ncols, nrows,
+                                                                                           nd_item);
+                         });
+    });
+}
+
+static void mul_mat_vec_q4_0_q8_1_sycl(const void * vx, const void * vy, float * dst, const int ncols, const int nrows,
                                        dpct::queue_ptr stream) {
     GGML_ASSERT(ncols % QK4_0 == 0);
     const int block_num_y = (nrows + GGML_SYCL_MMV_Y - 1) / GGML_SYCL_MMV_Y;
     const sycl::range<3> block_nums(1, 1, block_num_y);
     const sycl::range<3> block_dims(1, GGML_SYCL_MMV_Y, WARP_SIZE);
+
     {
-
         stream->submit([&](sycl::handler & cgh) {
-
+            cgh.parallel_for(sycl::nd_range<3>(block_nums * block_dims, block_dims),
-            cgh.parallel_for(
+                             [=](sycl::nd_item<3> item_ct1) [[sycl::reqd_sub_group_size(WARP_SIZE)]] {
-                sycl::nd_range<3>(block_nums * block_dims, block_dims),
+                                 mul_mat_vec_q<QK4_0, QI4_0, block_q4_0, VDR_Q4_0_Q8_1_MMVQ, vec_dot_q4_0_q8_1>(
-                [=](sycl::nd_item<3> item_ct1)
-                    [[sycl::reqd_sub_group_size(WARP_SIZE)]] {
-                        mul_mat_vec_q<QK4_0, QI4_0, block_q4_0,
-                                      VDR_Q4_0_Q8_1_MMVQ, vec_dot_q4_0_q8_1>(
                                      vx, vy, dst, ncols, nrows, item_ct1);
                              });
         });
@@ -916,14 +983,11 @@ static void mul_mat_vec_iq4_xs_q8_1_sycl(const void *vx, const void *vy,
     }
 }
 
-void ggml_sycl_op_mul_mat_vec_q(
+void ggml_sycl_op_mul_mat_vec_q(ggml_backend_sycl_context & ctx, const ggml_tensor * src0, const ggml_tensor * src1,
-    ggml_backend_sycl_context & ctx,
+                                ggml_tensor * dst, const char * src0_dd_i, const float * src1_ddf_i,
-    const ggml_tensor *src0, const ggml_tensor *src1, ggml_tensor *dst,
+                                const char * src1_ddq_i, float * dst_dd_i, const int64_t row_low,
-    const char *src0_dd_i, const float *src1_ddf_i, const char *src1_ddq_i,
+                                const int64_t row_high, const int64_t src1_ncols, const int64_t src1_padded_col_size,
-    float *dst_dd_i, const int64_t row_low, const int64_t row_high,
-    const int64_t src1_ncols, const int64_t src1_padded_col_size,
                                 const dpct::queue_ptr & stream) {
-
     const int64_t ne10 = src1->ne[0];
     GGML_ASSERT(ne10 % QK8_1 == 0);
 
@@ -931,21 +995,26 @@ void ggml_sycl_op_mul_mat_vec_q(
     const int64_t row_diff = row_high - row_low;
 
     int id;
-    SYCL_CHECK(
+    SYCL_CHECK(CHECK_TRY_ERROR(id = get_current_device_id()));
-        CHECK_TRY_ERROR(id = get_current_device_id()));
     const size_t q8_1_ts = sizeof(block_q8_1);
     const size_t q8_1_bs = QK8_1;
     // the main device has a larger memory buffer to hold the results from all GPUs
     // nrows_dst == nrows of the matrix that the kernel writes into
 
-    for (int i = 0; i < src1_ncols; i++)
+    for (int i = 0; i < src1_ncols; i++) {
-    {
         const size_t src1_ddq_i_offset = i * src1_padded_col_size * q8_1_ts / q8_1_bs;
         const char * src1_ddq_i_bs     = src1_ddq_i + src1_ddq_i_offset;
         float *      dst_dd_i_bs       = dst_dd_i + i * dst->ne[0];
         switch (src0->type) {
             case GGML_TYPE_Q4_0:
+                if ((ggml_tensor_extra_gpu *) dst->src[0]->extra &&
+                    ((ggml_tensor_extra_gpu *) dst->src[0]->extra)->optimized_feature.reorder) {
+                    GGML_SYCL_DEBUG("Calling reorder_mul_mat_vec_q4_0_q8_1_sycl\n");
+                    reorder_mul_mat_vec_q4_0_q8_1_sycl(src0_dd_i, src1_ddq_i_bs, dst_dd_i_bs, ne00, row_diff, stream);
+                } else {
+                    GGML_SYCL_DEBUG("Calling mul_mat_vec_q4_0_q8_1_sycl\n");
                     mul_mat_vec_q4_0_q8_1_sycl(src0_dd_i, src1_ddq_i_bs, dst_dd_i_bs, ne00, row_diff, stream);
+                }
                 break;
             case GGML_TYPE_Q4_1:
                 mul_mat_vec_q4_1_q8_1_sycl(src0_dd_i, src1_ddq_i_bs, dst_dd_i_bs, ne00, row_diff, stream);

ggml/src/ggml-sycl/quants.hpp

@@ -0,0 +1,61 @@
+//
+// MIT license
+// Copyright (C) 2025 Codeplay Software Ltd.
+// Copyright (C) 2025 Intel Corporation
+// SPDX-License-Identifier: MIT
+//
+
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+
+#ifndef GGML_SYCL_QUANTS_HPP
+#define GGML_SYCL_QUANTS_HPP
+
+#include "ggml-common.h"
+#include "ggml.h"
+
+namespace ggml_sycl_reordered {
+
+
+// The reordered block moves quants (qs) and  scales(d) to two
+// uniform regions of memory that is contiguous in the same tensor.
+// What this means is that instead of having:
+// [d0, qs0] [d1, qs1] [d2, qs2] ... [dN, qsN]
+// We have:
+// [qs0, qs1, qs2, ..., qsN]  [d0, d1, d2, ..., dN]
+//
+// Notes: out-of-bounds qs will run into d values
+// Aligment relies on the allocated size of qs
+
+template <ggml_type type> struct block_q_t;
+
+
+// qk number of weights / quants in a block
+// qr number of weights in a byte (described as 'before dequantization')
+//    for quantization types that has low and high bits split, qr is calculated with
+//    using the lower bits, e.g for Q6 quants QR6 is 2
+// qi number of 32 bit integers needed to represent all the quants from a block (`qs` field)
+// See ggml-common.h to see how these are calculated
+template <> struct block_q_t<GGML_TYPE_Q4_0> {
+    struct traits {
+        static constexpr uint32_t qk       = QK4_0;
+        static constexpr uint32_t qi       = QI4_0;
+        static constexpr uint32_t qr       = QR4_0;
+        static constexpr uint32_t vdr_mmvq = 2;
+    };
+
+    static constexpr int get_block_offset(const int block_index) { return block_index * (traits::qk / traits::qr); }
+
+    static constexpr int get_d_offset(int nrows, int ncols, const int block_index) {
+        return (ncols / traits::qr * nrows) + block_index * sizeof(ggml_half);
+    }
+
+    static constexpr int block_to_q8_1_ratio() { return traits::qk / QK8_1; }
+};
+
+}  // namespace ggml_sycl_reordered
+
+#endif  // GGML_SYCL_QUANTS_HPP

ggml/src/ggml-sycl/vecdotq.hpp

@@ -1,6 +1,6 @@
 //
 // MIT license
-// Copyright (C) 2024 Intel Corporation
+// Copyright (C) 2025 Intel Corporation
 // SPDX-License-Identifier: MIT
 //
 
@@ -14,8 +14,11 @@
 #define GGML_SYCL_VECDOTQ_HPP
 
 #include "dpct/helper.hpp"
+#include "ggml.h"
+#include "quants.hpp"
 
-typedef float (*vec_dot_q_sycl_t)(const void * __restrict__ vbq, const block_q8_1 * __restrict__ bq8_1, const int & iqs);
+typedef float (*vec_dot_q_sycl_t)(const void * __restrict__ vbq, const block_q8_1 * __restrict__ bq8_1,
+                                  const int & iqs);
 
 static __dpct_inline__ int get_int_from_int8(const int8_t* x8, const int& i32) {
   const uint16_t* x16 =
@@ -252,12 +255,59 @@ vec_dot_q6_K_q8_1_impl_mmvq(const int &vl, const int &vh,
 // VDR = vec dot ratio, how many contiguous integers each thread processes when the vec dot kernel is called
 // MMVQ = mul_mat_vec_q, MMQ = mul_mat_q
 
+template <ggml_type T> struct reorder_vec_dot_q_sycl {
+    static_assert(T != T, "ggml_type for reorder vecdot not implemented");
+};
+
+template <> struct reorder_vec_dot_q_sycl<GGML_TYPE_Q4_0> {
+    static constexpr ggml_type gtype = GGML_TYPE_Q4_0;
+
+    using q4_0_block  = ggml_sycl_reordered::block_q_t<GGML_TYPE_Q4_0>;
+    using q4_0_traits = typename q4_0_block::traits;
+
+    __dpct_inline__ float vec_dot_q4_0_q8_1_impl(const int * v, const int * u, const float & d4, const sycl::half2 & ds8) {
+        int sumi = 0;
+
+#pragma unroll
+        for (size_t i = 0; i < q4_0_traits::vdr_mmvq; ++i) {
+            const int vi0 = (v[i] >> 0) & 0x0F0F0F0F;
+            const int vi1 = (v[i] >> 4) & 0x0F0F0F0F;
+
+            // SIMD dot product of quantized values
+            sumi = dpct::dp4a(vi0, u[2 * i + 0], sumi);
+            sumi = dpct::dp4a(vi1, u[2 * i + 1], sumi);
+        }
+
+        const sycl::float2 ds8f = ds8.convert<float, sycl::rounding_mode::automatic>();
+
+        // second part effectively subtracts 8 from each quant value
+        return d4 * (sumi * ds8f.x() - (8 * q4_0_traits::vdr_mmvq / q4_0_traits::qi) * ds8f.y());
+    }
+
+    __dpct_inline__ float operator()(const void * __restrict__ vbq, const int ibx_offset, const int d_offset,
+                     const block_q8_1 * __restrict__ bq8_1, const int & iqs) {
+        const uint8_t * bq4_0 = static_cast<const uint8_t *>(vbq) + ibx_offset;
+        const ggml_half d     = *(reinterpret_cast<const ggml_half *>(static_cast<const uint8_t *>(vbq) + d_offset));
+        int             v[q4_0_traits::vdr_mmvq];
+        int             u[2 * q4_0_traits::vdr_mmvq];
+
+#pragma unroll
+
+        for (size_t i = 0; i < q4_0_traits::vdr_mmvq; ++i) {
+            v[i]         = get_int_from_uint8(bq4_0, iqs + i);
+            u[2 * i + 0] = get_int_from_int8_aligned(bq8_1->qs, iqs + i);
+            u[2 * i + 1] = get_int_from_int8_aligned(bq8_1->qs, iqs + i + q4_0_traits::qi);
+        }
+
+        return vec_dot_q4_0_q8_1_impl(v, u, d, bq8_1->ds);
+    };
+};
+
 #define VDR_Q4_0_Q8_1_MMVQ 2
 #define VDR_Q4_0_Q8_1_MMQ  4
 
 template <int vdr>
-static __dpct_inline__ float vec_dot_q4_0_q8_1_impl(const int *v, const int *u,
+static __dpct_inline__ float vec_dot_q4_0_q8_1_impl(const int * v, const int * u, const float & d4,
-                                                    const float &d4,
                                                     const sycl::half2 & ds8) {
     int sumi = 0;
 #pragma unroll
@@ -270,8 +320,7 @@ static __dpct_inline__ float vec_dot_q4_0_q8_1_impl(const int *v, const int *u,
         sumi = dpct::dp4a(vi1, u[2 * i + 1], sumi);
     }
 
-    const sycl::float2 ds8f =
+    const sycl::float2 ds8f = ds8.convert<float, sycl::rounding_mode::automatic>();
-        ds8.convert<float, sycl::rounding_mode::automatic>();
 
     // second part effectively subtracts 8 from each quant value
     return d4 * (sumi * ds8f.x() - (8 * vdr / QI4_0) * ds8f.y());