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authorHein-Pieter van Braam <hp@tmm.cx>2017-09-20 11:04:50 +0200
committerHein-Pieter van Braam <hp@tmm.cx>2017-09-21 18:28:28 +0200
commit22358babda1452ee6db4d662dff373472b93fdc6 (patch)
treef47c0c224ef12098147a3e289de7410758043fc2
parent4664d03a0e39be6dc8f5ba8154e1d6b776fa2293 (diff)
Implement Linux-style likely()/unlikely() macros
This implement branch prediction macros likely() and unlikely() like in Linux. When using these macros please ensure that when you use them the condition in the branch really is very, very likely or unlikely. Think 90+% of the time. Primarily useful for error checking. (And I implement these macros for all our error checking macros now) See this article for more information: https://kernelnewbies.org/FAQ/LikelyUnlikely There are more places where these macros may make sense in renderer and physics engine. Placing them will come in another commit down the line.
Diffstat
-rw-r--r--core/error_macros.h21
-rw-r--r--core/typedefs.h8
-rw-r--r--core/variant.cpp4
-rw-r--r--modules/gdscript/gd_function.cpp6
4 files changed, 24 insertions, 15 deletions
diff --git a/core/error_macros.h b/core/error_macros.h
index 005b0e32a3..1fa7f2c134 100644
--- a/core/error_macros.h
+++ b/core/error_macros.h
@@ -30,6 +30,7 @@
#ifndef ERROR_MACROS_H
#define ERROR_MACROS_H
+#include "typedefs.h"
/**
* Error macros. Unlike exceptions and asserts, these macros try to mantain consistency and stability
* inside the code. It is recommended to always return processable data, so in case of an error, the
@@ -130,7 +131,7 @@ extern bool _err_error_exists;
#define ERR_FAIL_INDEX(m_index, m_size) \
do { \
- if ((m_index) < 0 || (m_index) >= (m_size)) { \
+ if (unlikely((m_index) < 0 || (m_index) >= (m_size))) { \
_err_print_error(FUNCTION_STR, __FILE__, __LINE__, "Index " _STR(m_index) " out of size (" _STR(m_size) ")."); \
return; \
} else \
@@ -144,7 +145,7 @@ extern bool _err_error_exists;
#define ERR_FAIL_INDEX_V(m_index, m_size, m_retval) \
do { \
- if ((m_index) < 0 || (m_index) >= (m_size)) { \
+ if (unlikely((m_index) < 0 || (m_index) >= (m_size))) { \
_err_print_error(FUNCTION_STR, __FILE__, __LINE__, "Index " _STR(m_index) " out of size (" _STR(m_size) ")."); \
return m_retval; \
} else \
@@ -156,7 +157,7 @@ extern bool _err_error_exists;
*/
#define CRASH_BAD_INDEX(m_index, m_size) \
do { \
- if ((m_index) < 0 || (m_index) >= (m_size)) { \
+ if (unlikely((m_index) < 0 || (m_index) >= (m_size))) { \
_err_print_error(FUNCTION_STR, __FILE__, __LINE__, "FATAL: Index " _STR(m_index) " out of size (" _STR(m_size) ")."); \
GENERATE_TRAP \
} \
@@ -168,7 +169,7 @@ extern bool _err_error_exists;
#define ERR_FAIL_NULL(m_param) \
{ \
- if (!m_param) { \
+ if (unlikely(!m_param)) { \
_err_print_error(FUNCTION_STR, __FILE__, __LINE__, "Parameter ' " _STR(m_param) " ' is null."); \
return; \
} else \
@@ -177,7 +178,7 @@ extern bool _err_error_exists;
#define ERR_FAIL_NULL_V(m_param, m_retval) \
{ \
- if (!m_param) { \
+ if (unlikely(!m_param)) { \
_err_print_error(FUNCTION_STR, __FILE__, __LINE__, "Parameter ' " _STR(m_param) " ' is null."); \
return m_retval; \
} else \
@@ -190,7 +191,7 @@ extern bool _err_error_exists;
#define ERR_FAIL_COND(m_cond) \
{ \
- if (m_cond) { \
+ if (unlikely(m_cond)) { \
_err_print_error(FUNCTION_STR, __FILE__, __LINE__, "Condition ' " _STR(m_cond) " ' is true."); \
return; \
} else \
@@ -202,7 +203,7 @@ extern bool _err_error_exists;
#define CRASH_COND(m_cond) \
{ \
- if (m_cond) { \
+ if (unlikely(m_cond)) { \
_err_print_error(FUNCTION_STR, __FILE__, __LINE__, "FATAL: Condition ' " _STR(m_cond) " ' is true."); \
GENERATE_TRAP \
} \
@@ -216,7 +217,7 @@ extern bool _err_error_exists;
#define ERR_FAIL_COND_V(m_cond, m_retval) \
{ \
- if (m_cond) { \
+ if (unlikely(m_cond)) { \
_err_print_error(FUNCTION_STR, __FILE__, __LINE__, "Condition ' " _STR(m_cond) " ' is true. returned: " _STR(m_retval)); \
return m_retval; \
} else \
@@ -229,7 +230,7 @@ extern bool _err_error_exists;
#define ERR_CONTINUE(m_cond) \
{ \
- if (m_cond) { \
+ if (unlikely(m_cond)) { \
_err_print_error(FUNCTION_STR, __FILE__, __LINE__, "Condition ' " _STR(m_cond) " ' is true. Continuing..:"); \
continue; \
} else \
@@ -242,7 +243,7 @@ extern bool _err_error_exists;
#define ERR_BREAK(m_cond) \
{ \
- if (m_cond) { \
+ if (unlikely(m_cond)) { \
_err_print_error(FUNCTION_STR, __FILE__, __LINE__, "Condition ' " _STR(m_cond) " ' is true. Breaking..:"); \
break; \
} else \
diff --git a/core/typedefs.h b/core/typedefs.h
index 565e28020b..bf5c8b0f75 100644
--- a/core/typedefs.h
+++ b/core/typedefs.h
@@ -290,4 +290,12 @@ struct _GlobalLock {
#define __STRX(m_index) #m_index
#define __STR(m_index) __STRX(m_index)
+#ifdef __GNUC__
+#define likely(x) __builtin_expect(!!(x), 1)
+#define unlikely(x) __builtin_expect(!!(x), 0)
+#else
+#define likely(x) x
+#define unlikely(x) x
+#endif
+
#endif /* typedefs.h */
diff --git a/core/variant.cpp b/core/variant.cpp
index 52bdd4e22d..f70e4a5218 100644
--- a/core/variant.cpp
+++ b/core/variant.cpp
@@ -2469,10 +2469,10 @@ Variant::Variant(const Vector<Color> &p_array) {
void Variant::operator=(const Variant &p_variant) {
- if (this == &p_variant)
+ if (unlikely(this == &p_variant))
return;
- if (type != p_variant.type) {
+ if (unlikely(type != p_variant.type)) {
reference(p_variant);
return;
}
diff --git a/modules/gdscript/gd_function.cpp b/modules/gdscript/gd_function.cpp
index df7b16c96e..70340f0823 100644
--- a/modules/gdscript/gd_function.cpp
+++ b/modules/gdscript/gd_function.cpp
@@ -42,7 +42,7 @@ Variant *GDFunction::_get_variant(int p_address, GDInstance *p_instance, GDScrip
case ADDR_TYPE_SELF: {
- if (!p_instance) {
+ if (unlikely(!p_instance)) {
r_error = "Cannot access self without instance.";
return NULL;
}
@@ -54,7 +54,7 @@ Variant *GDFunction::_get_variant(int p_address, GDInstance *p_instance, GDScrip
} break;
case ADDR_TYPE_MEMBER: {
//member indexing is O(1)
- if (!p_instance) {
+ if (unlikely(!p_instance)) {
r_error = "Cannot access member without instance.";
return NULL;
}
@@ -279,7 +279,7 @@ Variant GDFunction::call(GDInstance *p_instance, const Variant **p_args, int p_a
#define GET_VARIANT_PTR(m_v, m_code_ofs) \
Variant *m_v; \
m_v = _get_variant(_code_ptr[ip + m_code_ofs], p_instance, _class, self, stack, err_text); \
- if (!m_v) \
+ if (unlikely(!m_v)) \
break;
#else
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-26 18:53:49 +0000