https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84100
--- Comment #12 from Martin Liška <marxin at gcc dot gnu.org> --- (In reply to Chris Hall from comment #11) > FWIW: __attribute__((aligned(32))) works nicely for functions. You are right, that works fine! It should be equal to use #pragma GCC optimize "align-functions=128" or the corresponding attribute. > > Generally there is little to be gained from aligning all loops/jumps/labels > in a given function or group of functions. > > Further, when code alignment issues bite, there is no guarantee that the > solution is to align all loops/jumps/labels in the same way. > > So, it would be nice to be able to apply __attribute__((aligned(n))) to > loops and/or labels... and perhaps to blocks. That way, precise alignment > could be applied precisely where it matters. > > I have been doing some detailed timing of relatively small operations, which > of course involves a loop to do the operation being timed many times. If > the timing loop is not 32-byte aligned, the timings I get are not stable. Such fine grained control would be nice, but it's very problematic to track such information from a front-end to back-end where the real alignment happens.
