https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90812
--- Comment #1 from Jozef Lawrynowicz <jozefl.gcc at gmail dot com> --- To check for 64-bit integer support, it seems that the "stdint_types" effective target keyword should be sufficient, although I'm not sure if it might be possible for a target to provide __INT64_TYPE__ but not stdint.h. Perhaps a new effective target keyword "int64type", which runs the following, is required: #ifndef __INT64_TYPE__ #error #endif
