Optimize zend_mm_small_size_to_bin()

It removes a cmov operation and has a much faster branch for small allocations (especially when handling strings) (<= 64 bytes)

3 files changed, 18 insertions, 16 deletions

diff --git a/Zend/zend_alloc.c b/Zend/zend_alloc.c
index bf147f55e5..bd3fe0ebcc 100644
--- a/Zend/zend_alloc.c
+++ b/Zend/zend_alloc.c
@@ -1202,17 +1202,19 @@ static zend_always_inline int zend_mm_small_size_to_bin(size_t size)
 	n = zend_mm_small_size_to_bit(size - 1);
 	return ((size-1) >> f1[n]) + f2[n];
 #else
-	int t1, t2, t3;
-
-	if (UNEXPECTED(size <= 8)) return 0;
-	t1 = (int)(size - 1);
-	t2 = zend_mm_small_size_to_bit(t1);
-	t3 = t2 - 6;
-	t3 = (t3 < 0) ? 0 : t3;
-	t2 = t3 + 3;
-	t1 = t1 >> t2;
-	t3 = t3 << 2;
-	return t1 + t3;
+	unsigned int t1, t2;
+
+	if (size <= 64) {
+		/* we need to support size == 0 ... */
+		return (size - !!size) >> 3;
+	} else {
+		t1 = size - 1;
+		t2 = zend_mm_small_size_to_bit(t1) - 3;
+		t1 = t1 >> t2;
+		t2 = t2 - 3;
+		t2 = t2 << 2;
+		return (int)(t1 + t2);
+	}
 #endif
 }
 
diff --git a/Zend/zend_closures.c b/Zend/zend_closures.c
index 50aa7d4188..251710e326 100644
--- a/Zend/zend_closures.c
+++ b/Zend/zend_closures.c
@@ -134,7 +134,7 @@ ZEND_METHOD(Closure, call)
 		fci_cache.function_handler = &my_function;
 
 		/* Runtime cache relies on bound scope to be immutable, hence we need a separate rt cache in case scope changed */
-		if (ZEND_USER_CODE(my_function.type) && closure->func.common.scope != Z_OBJCE_P(newthis)) {
+		if (ZEND_USER_CODE(my_function.type) && closure->func.common.scope != Z_OBJCE_P(newthis) && my_function.op_array.cache_size) {
 			my_function.op_array.run_time_cache = emalloc(my_function.op_array.cache_size);
 			memset(my_function.op_array.run_time_cache, 0, my_function.op_array.cache_size);
 		}
@@ -206,7 +206,7 @@ ZEND_METHOD(Closure, bind)
 	new_closure = (zend_closure *) Z_OBJ_P(return_value);
 
 	/* Runtime cache relies on bound scope to be immutable, hence we need a separate rt cache in case scope changed */
-	if (ZEND_USER_CODE(closure->func.type) && (closure->func.common.scope != new_closure->func.common.scope || (closure->func.op_array.fn_flags & ZEND_ACC_NO_RT_ARENA))) {
+	if (ZEND_USER_CODE(closure->func.type) && (closure->func.common.scope != new_closure->func.common.scope || (closure->func.op_array.fn_flags & ZEND_ACC_NO_RT_ARENA)) && new_closure->func.op_array.cache_size) {
 		new_closure->func.op_array.run_time_cache = emalloc(new_closure->func.op_array.cache_size);
 		memset(new_closure->func.op_array.run_time_cache, 0, new_closure->func.op_array.cache_size);
 
@@ -543,7 +543,7 @@ ZEND_API void zend_create_closure(zval *res, zend_function *func, zend_class_ent
 			zend_hash_init(closure->func.op_array.static_variables, zend_hash_num_elements(static_variables), NULL, ZVAL_PTR_DTOR, 0);
 			zend_hash_apply_with_arguments(static_variables, zval_copy_static_var, 1, closure->func.op_array.static_variables);
 		}
-		if (UNEXPECTED(!closure->func.op_array.run_time_cache)) {
+		if (UNEXPECTED(!closure->func.op_array.run_time_cache) && func->op_array.cache_size) {
 			closure->func.op_array.run_time_cache = func->op_array.run_time_cache = zend_arena_alloc(&CG(arena), func->op_array.cache_size);
 			memset(func->op_array.run_time_cache, 0, func->op_array.cache_size);
 		}
diff --git a/Zend/zend_execute.c b/Zend/zend_execute.c
index 67a6bc2d27..dcf2d4a7ce 100644
--- a/Zend/zend_execute.c
+++ b/Zend/zend_execute.c
@@ -2166,7 +2166,7 @@ static zend_always_inline void i_init_func_execute_data(zend_execute_data *execu
 		GC_REFCOUNT(Z_OBJ(EX(This)))++;
 	}
 
-	if (UNEXPECTED(!op_array->run_time_cache)) {
+	if (UNEXPECTED(!op_array->run_time_cache) && op_array->cache_size) {
 		op_array->run_time_cache = zend_arena_alloc(&CG(arena), op_array->cache_size);
 		memset(op_array->run_time_cache, 0, op_array->cache_size);
 	}
@@ -2193,7 +2193,7 @@ static zend_always_inline void i_init_code_execute_data(zend_execute_data *execu
 		GC_REFCOUNT(Z_OBJ(EX(This)))++;
 	}
 
-	if (!op_array->run_time_cache) {
+	if (!op_array->run_time_cache && op_array->cache_size) {
 		op_array->run_time_cache = emalloc(op_array->cache_size);
 		memset(op_array->run_time_cache, 0, op_array->cache_size);
 	}