Use __builtin_expect

Author: Rbiessy

ggml/src/ggml-sycl/common.hpp

@@ -45,11 +45,20 @@ 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 {                              \
-    if (g_ggml_sycl_debug)          \
-      fprintf(stderr, __VA_ARGS__); \
-  } while (0)
+#if defined(__clang__) && __has_builtin(__builtin_expect)
+// Hint the optimizer to pipeline the more likely following instruction in branches
+#define LIKELY(expr) __builtin_expect(expr, true)
+#define UNLIKELY(expr) __builtin_expect(expr, false)
+#else
+#define LIKELY(expr) (expr)
+#define UNLIKELY(expr) (expr)
+#endif
+
+#define GGML_SYCL_DEBUG(...)              \
+    do {                                  \
+        if (UNLIKELY(g_ggml_sycl_debug))  \
+            fprintf(stderr, __VA_ARGS__); \
+    } while (0)
 
 #define CHECK_TRY_ERROR(expr)                                            \
   [&]() {                                                                \
@@ -492,8 +501,10 @@ constexpr size_t ceil_div(const size_t m, const size_t n) {
 
 bool gpu_has_xmx(sycl::device &dev);
 
-template <int N, class T>
-void debug_print_array(const std::string& prefix, const T array[N]) {
+template <int N, class T> void debug_print_array(const std::string & prefix, const T array[N]) {
+    if (LIKELY(!g_ggml_sycl_debug)) {
+        return;
+    }
     std::stringstream ss;
     ss << prefix << "=[";
     for (std::size_t i = 0; i < N - 1; ++i) {
@@ -506,7 +517,11 @@ void debug_print_array(const std::string& prefix, const T array[N]) {
     GGML_SYCL_DEBUG("%s", ss.str().c_str());
 }
 
-inline void debug_print_tensor(const std::string& prefix, const ggml_tensor* tensor, const std::string& suffix = "") {
+inline void debug_print_tensor(const std::string & prefix, const ggml_tensor * tensor,
+                               const std::string & suffix = "") {
+    if (LIKELY(!g_ggml_sycl_debug)) {
+        return;
+    }
     GGML_SYCL_DEBUG("%s=", prefix.c_str());
     if (tensor) {
         GGML_SYCL_DEBUG("'%s':type=%s", tensor->name, ggml_type_name(tensor->type));
@@ -526,7 +541,7 @@ inline void debug_print_tensor(const std::string& prefix, const ggml_tensor* ten
 
 struct scope_op_debug_print {
   scope_op_debug_print(const std::string& func, const ggml_tensor* dst, std::size_t num_src, const std::string& suffix = "") : func(func) {
-    if (!g_ggml_sycl_debug) {
+    if (LIKELY(!g_ggml_sycl_debug)) {
         return;
     }
     GGML_SYCL_DEBUG("[SYCL][OP] call %s:", func.c_str());