Use __attribute__((assume())) in ZEND_ASSUME when available

Author: iluuu1994

Zend/Zend.m4

@@ -405,3 +405,23 @@ AC_LINK_IFELSE([AC_LANG_PROGRAM([[
 if test "$ac_cv_cpuid_count_available" = "yes"; then
   AC_DEFINE([HAVE_CPUID_COUNT], 1, [whether __cpuid_count is available])
 fi
+
+AC_MSG_CHECKING(whether statement attribute assume is available)
+
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+struct Foo {
+	int bar;
+};
+void foo(struct Foo *foo) {
+	__attribute__((assume(foo->bar != 0)));
+}
+]], [[
+]])], [
+  HAVE_STATEMENT_ATTRIBUTE_ASSUME=yes
+], [
+  HAVE_STATEMENT_ATTRIBUTE_ASSUME=no
+])
+if test "$HAVE_STATEMENT_ATTRIBUTE_ASSUME" = "yes"; then
+  AC_DEFINE([HAVE_STATEMENT_ATTRIBUTE_ASSUME], 1, [whether statement attribute assume is available])
+fi
+AC_MSG_RESULT($HAVE_STATEMENT_ATTRIBUTE_ASSUME)

Zend/zend_portability.h

@@ -89,6 +89,8 @@
 
 #if defined(ZEND_WIN32) && !defined(__clang__)
 # define ZEND_ASSUME(c)	__assume(c)
+#elif HAVE_STATEMENT_ATTRIBUTE_ASSUME
+# define ZEND_ASSUME(c)	__attribute__((assume(c)))
 #elif defined(__clang__) && __has_builtin(__builtin_assume)
 # pragma clang diagnostic ignored "-Wassume"
 # define ZEND_ASSUME(c)	__builtin_assume(c)