add performance-portable tuning for register-tile and subgroup matmul (#22241)

Author: SharmaRithik

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

@@ -26,20 +26,23 @@
 // Matrix multiplication parameters
 
 // Register tiling parameters
-#define WEBGPU_MUL_MAT_TILE_M    8
-#define WEBGPU_MUL_MAT_TILE_N    8
+#define WEBGPU_MUL_MAT_TILE_M    4
+#define WEBGPU_MUL_MAT_TILE_N    4
 #define WEBGPU_MUL_MAT_WG_SIZE_M 8
 #define WEBGPU_MUL_MAT_WG_SIZE_N 8
-#define WEBGPU_MUL_MAT_TILE_K    32
+#define WEBGPU_MUL_MAT_REG_TILE_K_FLOAT 8
+#define WEBGPU_MUL_MAT_REG_TILE_K_QUANT 32
 
 // Subgroup matrix parameters
 // The number of subgroups in the M dimension
 #define WEBGPU_MUL_MAT_SUBGROUP_M        2
 // The number of subgroups in the N dimension
-#define WEBGPU_MUL_MAT_SUBGROUP_N        2
+#define WEBGPU_MUL_MAT_SUBGROUP_N        4
 // The number of subgroup matrices each subgroup accumulates over
 #define WEBGPU_MUL_MAT_SUBGROUP_MATRIX_M 4
 #define WEBGPU_MUL_MAT_SUBGROUP_MATRIX_N 2
+#define WEBGPU_MUL_MAT_SUBGROUP_TILE_K_FLOAT 32
+#define WEBGPU_MUL_MAT_SUBGROUP_TILE_K_QUANT 32
 
 // Matrix-vector multiplication parameters
 #define WEBGPU_MUL_MAT_VEC_WG_SIZE 256
@@ -1734,13 +1737,24 @@ class ggml_webgpu_shader_lib {
         // VEC/SCALAR controls
         defines.push_back(key.vectorized ? "VEC" : "SCALAR");
 
+        const bool is_quant = ggml_is_quantized(context.src0->type);
+
+        uint32_t tile_k;
+        if (key.use_subgroup_matrix) {
+            tile_k = is_quant ? WEBGPU_MUL_MAT_SUBGROUP_TILE_K_QUANT
+                              : WEBGPU_MUL_MAT_SUBGROUP_TILE_K_FLOAT;
+        } else {
+            tile_k = is_quant ? WEBGPU_MUL_MAT_REG_TILE_K_QUANT
+                              : WEBGPU_MUL_MAT_REG_TILE_K_FLOAT;
+        }
+
         // Tiles
         defines.push_back("TILE_M=" + std::to_string(WEBGPU_MUL_MAT_TILE_M) + "u");
         defines.push_back("TILE_N=" + std::to_string(WEBGPU_MUL_MAT_TILE_N) + "u");
-        defines.push_back("TILE_K=" + std::to_string(WEBGPU_MUL_MAT_TILE_K) + "u");
 
         // Subgroup matrix specifics
         if (key.use_subgroup_matrix) {
+            defines.push_back("TILE_K=" + std::to_string(tile_k) + "u");
             defines.push_back("MAX_SUBGROUP_SIZE=" + std::to_string(context.max_subgroup_size) + "u");
             defines.push_back("SUBGROUP_M=" + std::to_string(WEBGPU_MUL_MAT_SUBGROUP_M) + "u");
             defines.push_back("SUBGROUP_N=" + std::to_string(WEBGPU_MUL_MAT_SUBGROUP_N) + "u");
@@ -1760,12 +1774,13 @@ class ggml_webgpu_shader_lib {
         if (!key.use_subgroup_matrix) {
             defines.push_back("WORKGROUP_SIZE_M=" + std::to_string(WEBGPU_MUL_MAT_WG_SIZE_M) + "u");
             defines.push_back("WORKGROUP_SIZE_N=" + std::to_string(WEBGPU_MUL_MAT_WG_SIZE_N) + "u");
+            defines.push_back("TILE_K=" + std::to_string(tile_k) + "u");
         }
 
         auto processed = preprocessor.preprocess(shader_src, defines);
 
         auto decisions                 = std::make_shared<ggml_webgpu_mul_mat_shader_decisions>();
-        decisions->tile_k              = WEBGPU_MUL_MAT_TILE_K;
+        decisions->tile_k              = tile_k;
         decisions->tile_m              = WEBGPU_MUL_MAT_TILE_M;
         decisions->tile_n              = WEBGPU_MUL_MAT_TILE_N;
         decisions->use_subgroup_matrix = key.use_subgroup_matrix;
@@ -1962,10 +1977,15 @@ class ggml_webgpu_shader_lib {
 
         defines.push_back("SCALAR");
 
+        // mul_mat_id is register-tile only.
+        const uint32_t tile_k = ggml_is_quantized(context.src0->type)
+                                    ? WEBGPU_MUL_MAT_REG_TILE_K_QUANT
+                                    : WEBGPU_MUL_MAT_REG_TILE_K_FLOAT;
+
         // Tiles
         defines.push_back("TILE_M=" + std::to_string(WEBGPU_MUL_MAT_TILE_M) + "u");
         defines.push_back("TILE_N=" + std::to_string(WEBGPU_MUL_MAT_TILE_N) + "u");
-        defines.push_back("TILE_K=" + std::to_string(WEBGPU_MUL_MAT_TILE_K) + "u");
+        defines.push_back("TILE_K=" + std::to_string(tile_k) + "u");
 
         defines.push_back("WORKGROUP_SIZE_M=" + std::to_string(WEBGPU_MUL_MAT_WG_SIZE_M) + "u");
         defines.push_back("WORKGROUP_SIZE_N=" + std::to_string(WEBGPU_MUL_MAT_WG_SIZE_N) + "u");
@@ -1976,7 +1996,7 @@ class ggml_webgpu_shader_lib {
         auto processed = preprocessor.preprocess(wgsl_mul_mat_id, defines);
 
         auto decisions       = std::make_shared<ggml_webgpu_mul_mat_shader_decisions>();
-        decisions->tile_k    = WEBGPU_MUL_MAT_TILE_K;
+        decisions->tile_k    = tile_k;
         decisions->tile_m    = WEBGPU_MUL_MAT_TILE_M;
         decisions->tile_n    = WEBGPU_MUL_MAT_TILE_N;
         decisions->wg_size_m = WEBGPU_MUL_MAT_WG_SIZE_M;