https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79552
--- Comment #7 from Uroš Bizjak <ubizjak at gmail dot com> --- (In reply to Katsunori Kumatani from comment #3) > In my case, I explicitly told GCC what memory I was going to clobber (with > the "=m"(*m) output operand). In fact, without telling it I was going to > clobber it, GCC would remove the asm completely because no other output is > used at all! This dereference struct trick is also explained in the manual > for Extended Asm, too. Indeed, I wasn't read the testcase carefully enough.
