> On Dec 15, 2015, at 7:52 AM, Bernd Schmidt <bschm...@redhat.com> wrote: > > On 12/14/2015 09:10 AM, Segher Boessenkool wrote: >> That, and adding a memory clobber degrades performance for a lot of >> existing basic asm that does not expect the clobber, e.g. asm(""), >> asm("#"), asm("nop"), ... > > I wonder about this. People keep bringing up "a lot of existing basic asm" in > general, but are there any known examples in real software?
In the codebase for the product I work on, I see about 200 of them. Many of those are the likes of asm("sync") for MIPS, which definitely wants to be treated as if it were asm ("sync" : : : "memory"). That's not counting the hundreds I see in gdb/stubs -- those are "outside a function" flavor. paul