Hi, this patch fixes BUILT_IN_UNREACHABLE declaration of C frontned. The function is also pure (so DSE can do its job). As a special case ECF flags for CONST & NORETURN also add looping, so this declaration is correct.
The implicit declaration of the builtin is already set this way. Bootstrapped/regtested x86_64-linux, comitted as obvious. Honza * builtins.def (BUILT_IN_UNREACHABLE): Make ATTR_CONST_NORETURN_NOTHROW_LEAF_LIST. * builtin-attrs.def (ATTR_CONST_NORETURN_NOTHROW_LEAF_LIST): Define. Index: builtins.def =================================================================== --- builtins.def (revision 192537) +++ builtins.def (working copy) @@ -728,7 +728,7 @@ DEF_GCC_BUILTIN (BUILT_IN_SETJMP, DEF_EXT_LIB_BUILTIN (BUILT_IN_STRFMON, "strfmon", BT_FN_SSIZE_STRING_SIZE_CONST_STRING_VAR, ATTR_FORMAT_STRFMON_NOTHROW_3_4) DEF_LIB_BUILTIN (BUILT_IN_STRFTIME, "strftime", BT_FN_SIZE_STRING_SIZE_CONST_STRING_CONST_PTR, ATTR_FORMAT_STRFTIME_NOTHROW_3_0) DEF_GCC_BUILTIN (BUILT_IN_TRAP, "trap", BT_FN_VOID, ATTR_NORETURN_NOTHROW_LEAF_LIST) -DEF_GCC_BUILTIN (BUILT_IN_UNREACHABLE, "unreachable", BT_FN_VOID, ATTR_NORETURN_NOTHROW_LEAF_LIST) +DEF_GCC_BUILTIN (BUILT_IN_UNREACHABLE, "unreachable", BT_FN_VOID, ATTR_CONST_NORETURN_NOTHROW_LEAF_LIST) DEF_GCC_BUILTIN (BUILT_IN_UNWIND_INIT, "unwind_init", BT_FN_VOID, ATTR_NULL) DEF_GCC_BUILTIN (BUILT_IN_UPDATE_SETJMP_BUF, "update_setjmp_buf", BT_FN_VOID_PTR_INT, ATTR_NULL) DEF_GCC_BUILTIN (BUILT_IN_VA_COPY, "va_copy", BT_FN_VOID_VALIST_REF_VALIST_ARG, ATTR_NOTHROW_LEAF_LIST) Index: builtin-attrs.def =================================================================== --- builtin-attrs.def (revision 192537) +++ builtin-attrs.def (working copy) @@ -131,6 +131,8 @@ DEF_ATTR_TREE_LIST (ATTR_NORETURN_NOTHRO ATTR_NULL, ATTR_NOTHROW_LIST) DEF_ATTR_TREE_LIST (ATTR_NORETURN_NOTHROW_LEAF_LIST, ATTR_NORETURN,\ ATTR_NULL, ATTR_NOTHROW_LEAF_LIST) +DEF_ATTR_TREE_LIST (ATTR_CONST_NORETURN_NOTHROW_LEAF_LIST, ATTR_CONST,\ + ATTR_NULL, ATTR_NORETURN_NOTHROW_LEAF_LIST) DEF_ATTR_TREE_LIST (ATTR_MALLOC_NOTHROW_LIST, ATTR_MALLOC, \ ATTR_NULL, ATTR_NOTHROW_LIST) DEF_ATTR_TREE_LIST (ATTR_MALLOC_NOTHROW_LEAF_LIST, ATTR_MALLOC, \