I've been trying to use the complex type associated with __float128, but it's rejected:
$ cat u.c int main (void) { __complex__ __float128 z; } $ gcc u.c u.c: In function main: u.c:1: error: expected =, ,, ;, asm or __attribute__ before z -- Summary: Complex __float128 is rejected Product: gcc Version: 4.3.0 Status: UNCONFIRMED Keywords: rejects-valid Severity: normal Priority: P3 Component: target AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: fxcoudert at gcc dot gnu dot org GCC build triplet: x86_64-unknown-linux-gnu GCC host triplet: x86_64-unknown-linux-gnu GCC target triplet: x86_64-unknown-linux-gnu http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32187