[webgpu] Fix errors found by matmul2bits tests (microsoft#26880)

Fix bugs found in microsoft#26862.

Author: qjia7

onnxruntime/contrib_ops/webgpu/quantization/matmul_nbits.wgsl.template

@@ -84,6 +84,21 @@ $MAIN {
 #if n_bits == 4
         var sum = output_element_t(0);
         var a_offset = idx * (8 / component_a) * component_b;
+#if component_b == 1
+        let b_value_lower = vec4<output_element_t>(unpack4xU8(b_value & 0x0F0F0F0Fu)) - vec4<output_element_t>(zero);
+        let b_value_upper = vec4<output_element_t>(unpack4xU8((b_value >> 4) & 0x0F0F0F0Fu)) - vec4<output_element_t>(zero);
+        let b0 = vec4<output_element_t>(b_value_lower[0], b_value_upper[0], b_value_lower[1], b_value_upper[1]) * scale_b;
+        let b1 = vec4<output_element_t>(b_value_lower[2], b_value_upper[2], b_value_lower[3], b_value_upper[3]) * scale_b;
+#if component_a == 1
+        sum += dot(vec4<output_element_t>(tile_A[a_offset], tile_A[a_offset + 1], tile_A[a_offset + 2], tile_A[a_offset + 3]), b0) +
+                    dot(vec4<output_element_t>(tile_A[a_offset + 4], tile_A[a_offset + 5], tile_A[a_offset + 6], tile_A[a_offset + 7]), b1);
+#elif component_a == 2
+        sum += dot(vec4<output_element_t>(tile_A[a_offset], tile_A[a_offset + 1]), b0) +
+                    dot(vec4<output_element_t>(tile_A[a_offset + 2], tile_A[a_offset + 3]), b1);
+#elif component_a == 4
+        sum += dot(tile_A[a_offset], b0) + dot(tile_A[a_offset + 1], b1);
+#endif
+#else
         for (var i = 0u; i < component_b; i++) {
             let b_value_lower = vec4<output_element_t>(unpack4xU8(b_value[i] & 0x0F0F0F0Fu)) - vec4<output_element_t>(zero);
             let b_value_upper = vec4<output_element_t>(unpack4xU8((b_value[i] >> 4) & 0x0F0F0F0Fu)) - vec4<output_element_t>(zero);
@@ -102,25 +117,63 @@ $MAIN {
             a_offset += 2;
 #endif
         }
+#endif
 #elif n_bits == 8
         var sum = output_element_t(0);
         var a_offset = idx * (4 / component_a) * component_b;
+#if component_b == 1
+        let b_value_unpacked = (vec4<output_element_t>(unpack4xU8(b_value)) - vec4<output_element_t>(zero)) * scale_b;
+#if component_a == 1
+        sum += dot(vec4<output_element_t>(tile_A[a_offset], tile_A[a_offset + 1], tile_A[a_offset + 2], tile_A[a_offset + 3]), b_value_unpacked);
+#elif component_a == 2
+        sum += dot(vec4<output_element_t>(tile_A[a_offset], tile_A[a_offset + 1]), b_value_unpacked);
+#elif component_a == 4
+        sum += dot(tile_A[a_offset], b_value_unpacked);
+#endif
+#else
         for (var i = 0u; i < component_b; i++) {
-            let b_value = (vec4<output_element_t>(unpack4xU8(b_value[i])) - vec4<output_element_t>(zero)) * scale_b;
+            let b_value_unpacked = (vec4<output_element_t>(unpack4xU8(b_value[i])) - vec4<output_element_t>(zero)) * scale_b;
 #if component_a == 1
-            sum += dot(vec4<output_element_t>(tile_A[a_offset], tile_A[a_offset + 1], tile_A[a_offset + 2], tile_A[a_offset + 3]), b_value);
+            sum += dot(vec4<output_element_t>(tile_A[a_offset], tile_A[a_offset + 1], tile_A[a_offset + 2], tile_A[a_offset + 3]), b_value_unpacked);
             a_offset += 4;
 #elif component_a == 2
-            sum += dot(vec4<output_element_t>(tile_A[a_offset], tile_A[a_offset + 1]), b_value);
+            sum += dot(vec4<output_element_t>(tile_A[a_offset], tile_A[a_offset + 1]), b_value_unpacked);
             a_offset += 2;
 #elif component_a == 4
-            sum += dot(tile_A[a_offset], b_value);
+            sum += dot(tile_A[a_offset], b_value_unpacked);
             a_offset += 1;
 #endif
         }
+#endif
 #elif n_bits == 2
         var sum = output_element_t(0);
         var a_offset = idx * (16 / component_a) * component_b;
+#if component_b == 1
+        let b_data_0 = vec4<output_element_t>(unpack4xU8(b_value & 0x03030303u)) - vec4<output_element_t>(zero);
+        let b_data_1 = vec4<output_element_t>(unpack4xU8((b_value >> 2) & 0x03030303u)) - vec4<output_element_t>(zero);
+        let b_data_2 = vec4<output_element_t>(unpack4xU8((b_value >> 4) & 0x03030303u)) - vec4<output_element_t>(zero);
+        let b_data_3 = vec4<output_element_t>(unpack4xU8((b_value >> 6) & 0x03030303u)) - vec4<output_element_t>(zero);
+
+        let b0 = vec4<output_element_t>(b_data_0[0], b_data_1[0], b_data_2[0], b_data_3[0]) * scale_b;
+        let b1 = vec4<output_element_t>(b_data_0[1], b_data_1[1], b_data_2[1], b_data_3[1]) * scale_b;
+        let b2 = vec4<output_element_t>(b_data_0[2], b_data_1[2], b_data_2[2], b_data_3[2]) * scale_b;
+        let b3 = vec4<output_element_t>(b_data_0[3], b_data_1[3], b_data_2[3], b_data_3[3]) * scale_b;
+
+#if component_a == 1
+        sum += dot(vec4<output_element_t>(tile_A[a_offset], tile_A[a_offset + 1], tile_A[a_offset + 2], tile_A[a_offset + 3]), b0) +
+                    dot(vec4<output_element_t>(tile_A[a_offset + 4], tile_A[a_offset + 5], tile_A[a_offset + 6], tile_A[a_offset + 7]), b1) +
+                    dot(vec4<output_element_t>(tile_A[a_offset + 8], tile_A[a_offset + 9], tile_A[a_offset + 10], tile_A[a_offset + 11]), b2) +
+                    dot(vec4<output_element_t>(tile_A[a_offset + 12], tile_A[a_offset + 13], tile_A[a_offset + 14], tile_A[a_offset + 15]), b3);
+#elif component_a == 2
+        sum += dot(vec4<output_element_t>(tile_A[a_offset], tile_A[a_offset + 1]), b0) +
+                    dot(vec4<output_element_t>(tile_A[a_offset + 2], tile_A[a_offset + 3]), b1) +
+                    dot(vec4<output_element_t>(tile_A[a_offset + 4], tile_A[a_offset + 5]), b2) +
+                    dot(vec4<output_element_t>(tile_A[a_offset + 6], tile_A[a_offset + 7]), b3);
+#elif component_a == 4
+        sum += dot(tile_A[a_offset], b0) + dot(tile_A[a_offset + 1], b1) +
+                dot(tile_A[a_offset + 2], b2) + dot(tile_A[a_offset + 3], b3);
+#endif
+#else
         for (var i = 0u; i < component_b; i++) {
             let b_data_0 = vec4<output_element_t>(unpack4xU8(b_value[i] & 0x03030303u)) - vec4<output_element_t>(zero);
             let b_data_1 = vec4<output_element_t>(unpack4xU8((b_value[i] >> 2) & 0x03030303u)) - vec4<output_element_t>(zero);
@@ -150,6 +203,7 @@ $MAIN {
             a_offset += 4;
 #endif
         }
+#endif
 #endif
 
         inter_results[local_row_offset + idy][idx] += sum;

onnxruntime/test/contrib_ops/matmul_2bits_test.cc

@@ -197,10 +197,12 @@ void RunTest2Bits(const TestOptions2Bits& opts) {
 
   std::vector<std::unique_ptr<IExecutionProvider>> execution_providers;
   if constexpr (std::is_same<T1, float>::value) {
-    execution_providers.emplace_back(DefaultCpuExecutionProvider());
 #ifdef USE_WEBGPU
-    execution_providers.push_back(DefaultWebGpuExecutionProvider());
+    if (!opts.has_zero_point) {
+      execution_providers.push_back(DefaultWebGpuExecutionProvider());
+    }
 #endif
+    execution_providers.emplace_back(DefaultCpuExecutionProvider());
     test.ConfigEps(std::move(execution_providers));
     test.RunWithConfig();
   }