ggml-webgpu: add Q1_0 support (ggml-org#22374)

* add fast matmul matvec q1_0 kernel

* ggml-webgpu: drop redundant zero-fills in Q1_0 shmem init

Author: SharmaRithik

ggml/src/ggml-webgpu/ggml-webgpu-shader-lib.hpp

@@ -1287,6 +1287,7 @@ class ggml_webgpu_shader_lib {
                     std::transform(type_upper.begin(), type_upper.end(), type_upper.begin(), ::toupper);
 
                     switch (key.src_type) {
+                        case GGML_TYPE_Q1_0:
                         case GGML_TYPE_Q4_0:
                         case GGML_TYPE_Q5_0:
                         case GGML_TYPE_Q8_0:
@@ -1323,7 +1324,9 @@ class ggml_webgpu_shader_lib {
 
                     defines.push_back("DST_TYPE=f32");
 
-                    if ((key.src_type >= GGML_TYPE_Q4_0 && key.src_type <= GGML_TYPE_Q8_1) ||
+                    if (key.src_type == GGML_TYPE_Q1_0) {
+                        defines.push_back("BLOCK_SIZE=128u");
+                    } else if ((key.src_type >= GGML_TYPE_Q4_0 && key.src_type <= GGML_TYPE_Q8_1) ||
                         key.src_type == GGML_TYPE_IQ4_NL) {
                         defines.push_back("BLOCK_SIZE=32u");
                     } else if (key.src_type >= GGML_TYPE_Q2_K) {
@@ -1657,7 +1660,9 @@ class ggml_webgpu_shader_lib {
         uint32_t wg_size        = WEBGPU_MUL_MAT_VEC_WG_SIZE;
         uint32_t outputs_per_wg = WEBGPU_MUL_MAT_VEC_FLOAT_OUTPUTS_PER_WG;
 
-        if (key.src0_type >= GGML_TYPE_Q2_K) {
+        if (key.src0_type == GGML_TYPE_Q1_0) {
+            outputs_per_wg = WEBGPU_MUL_MAT_VEC_LEGACY_Q_OUTPUTS_PER_WG;
+        } else if (key.src0_type >= GGML_TYPE_Q2_K) {
             outputs_per_wg = WEBGPU_MUL_MAT_VEC_K_Q_OUTPUTS_PER_WG;
         } else if (key.src0_type >= GGML_TYPE_Q4_0) {
             outputs_per_wg = WEBGPU_MUL_MAT_VEC_LEGACY_Q_OUTPUTS_PER_WG;

ggml/src/ggml-webgpu/ggml-webgpu.cpp

@@ -1389,6 +1389,7 @@ static webgpu_encoded_op ggml_webgpu_mul_mat(webgpu_context & ctx,
                 case GGML_TYPE_Q5_K:
                 case GGML_TYPE_Q3_K:
                 case GGML_TYPE_Q2_K:
+                case GGML_TYPE_Q1_0:
                     use_fast = true;
                     break;
                 case GGML_TYPE_IQ1_S:
@@ -3736,6 +3737,7 @@ static bool ggml_backend_webgpu_device_supports_buft(ggml_backend_dev_t dev, ggm
 
 static bool ggml_webgpu_supported_qtype(ggml_type type) {
     switch (type) {
+        case GGML_TYPE_Q1_0:
         case GGML_TYPE_Q4_0:
         case GGML_TYPE_Q4_1:
         case GGML_TYPE_Q5_0:
@@ -3830,6 +3832,7 @@ static bool ggml_backend_webgpu_device_supports_op(ggml_backend_dev_t dev, const
                         switch (src0->type) {
                             case GGML_TYPE_F32:
                             case GGML_TYPE_F16:
+                            case GGML_TYPE_Q1_0:
                             case GGML_TYPE_Q4_0:
                             case GGML_TYPE_Q4_1:
                             case GGML_TYPE_Q5_0:
@@ -3868,6 +3871,7 @@ static bool ggml_backend_webgpu_device_supports_op(ggml_backend_dev_t dev, const
                     switch (src0->type) {
                         case GGML_TYPE_F32:
                         case GGML_TYPE_F16:
+                        case GGML_TYPE_Q1_0:
                         case GGML_TYPE_Q4_0:
                         case GGML_TYPE_Q4_1:
                         case GGML_TYPE_Q5_0:

ggml/src/ggml-webgpu/wgsl-shaders/get_rows.wgsl

@@ -27,6 +27,24 @@ fn copy_elements(src_base: u32, dst_base: u32, offset: u32) {
 }
 #endif
 
+#ifdef Q1_0
+fn copy_elements(src_base: u32, dst_base: u32, offset: u32) {
+    let block_byte_base = (src_base + offset) * 18;
+    let d = load_f16_as_f32_at_src(block_byte_base);
+    for (var j: u32 = 0u; j < 4u; j++) {
+        let q_packed = load_u32_at_src(block_byte_base + 2u + j * 4u);
+        let dst_base128 = dst_base + offset * 128u + j * 32u;
+        for (var k: u32 = 0; k < 4u; k++) {
+            let q_byte = get_byte(q_packed, k);
+            for (var bit: u32 = 0; bit < 8u; bit++) {
+                let w = select(-d, d, ((q_byte >> bit) & 1u) != 0u);
+                dst[dst_base128 + k * 8u + bit] = w;
+            }
+        }
+    }
+}
+#endif
+
 #ifdef Q4_0
 fn copy_elements(src_base: u32, dst_base: u32, offset: u32) {
     let block_byte_base = (src_base + offset) * 18; // Block stride: 18 bytes

ggml/src/ggml-webgpu/wgsl-shaders/mul_mat_decls.tmpl

@@ -61,6 +61,39 @@ fn init_shmem_src1(thread_id: u32, batch_offset: u32, offset_n: u32, k_outer: u3
 #endif // INIT_SRC1_SHMEM_FLOAT
 #endif
 
+#ifdef INIT_SRC0_SHMEM_Q1_0
+const BLOCK_SIZE = 128u;
+const BLOCK_SIZE_BYTES = 18u;
+const NQ = 8u; // 8 weights (1 byte of qs) per thread per iteration
+
+fn init_shmem_src0(thread_id: u32, batch_offset: u32, offset_m: u32, k_outer: u32) {
+    for (var i = thread_id * NQ; i < TILE_SRC0_SHMEM; i += TOTAL_WORKGROUP_SIZE * NQ) {
+        let tile_m = i / TILE_K;
+        let tile_k_start = i % TILE_K;
+        let global_m = offset_m + tile_m;
+        let global_k_start = k_outer + tile_k_start;
+
+        if (global_m >= params.m) {
+            break;
+        }
+
+        let block_k = global_k_start / BLOCK_SIZE;
+        let byte_in_block = (global_k_start % BLOCK_SIZE) / 8u;
+        let src0_idx = batch_offset + global_m * params.stride_01 + block_k;
+        let block_byte_base = src0_idx * BLOCK_SIZE_BYTES;
+        let d = load_f16_at_src0(block_byte_base);
+        let q_byte = load_u32_at_src0(block_byte_base + 2u + byte_in_block) & 0xFFu;
+
+        for (var bit = 0u; bit < NQ; bit++) {
+            let global_k = global_k_start + bit;
+            if (global_k < params.k) {
+                shmem[i + bit] = select(-d, d, ((q_byte >> bit) & 1u) != 0u);
+            }
+        }
+    }
+}
+#endif // INIT_SRC0_SHMEM_Q1_0
+
 #ifdef INIT_SRC0_SHMEM_Q4_0
 const BLOCK_SIZE = 32u;
 const BLOCK_SIZE_BYTES = 18u;

ggml/src/ggml-webgpu/wgsl-shaders/mul_mat_vec.wgsl

@@ -128,6 +128,38 @@ fn main(
     }
 #endif
 
+#ifdef MUL_ACC_Q1_0
+#define BLOCK_SIZE 128
+#define BLOCK_SIZE_BYTES 18
+#define THREADS_PER_BLOCK 16
+#define ELEMS_PER_THREAD (BLOCK_SIZE/THREADS_PER_BLOCK)
+
+    let num_blocks = params.k / BLOCK_SIZE;
+    let thread_within_block = thread_id % THREADS_PER_BLOCK;
+    for (var block = thread_id / THREADS_PER_BLOCK; block < num_blocks; block += WG_SIZE / THREADS_PER_BLOCK) {
+        let x_base = src1_idx_base + block * BLOCK_SIZE + thread_within_block * ELEMS_PER_THREAD;
+        var x_block: array<f32, ELEMS_PER_THREAD>;
+        for (var i = 0u; i < ELEMS_PER_THREAD; i++) {
+            x_block[i] = f32(src1[x_base + i]);
+        }
+
+        for (var row = 0u; row < OUTPUTS_PER_WG; row++) {
+            let output_row = row_base + row;
+            if (output_row < params.m) {
+                let block_byte_base = (src0_batch_offset + output_row * params.stride_01 + block) * BLOCK_SIZE_BYTES;
+                let d = f32(load_f16_at_src0(block_byte_base));
+                let q_byte = load_u32_at_src0(block_byte_base + 2u + thread_within_block) & 0xFFu;
+                var row_sum = 0.0;
+                for (var bit = 0u; bit < 8u; bit++) {
+                    let w = select(-d, d, ((q_byte >> bit) & 1u) != 0u);
+                    row_sum += w * x_block[bit];
+                }
+                acc[row] += row_sum;
+            }
+        }
+    }
+#endif
+
 #ifdef MUL_ACC_Q4_0
 #define BLOCK_SIZE 32
 #define BLOCK_SIZE_BYTES 18