https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64434
--- Comment #8 from Yuri Rumyantsev <ysrumyan at gmail dot com> --- The issue is caused by operand canonicalization, i.e. there is special operand odering for commutative operations to have the same representation for a + b and b + a. If computation of second operand requires more operations this may lead to live range increasing ( for live variables computed by first operand). If we swap these operands we get live range shrinking which is essential for 32-bit targets having only few registers. Hope it will help you to understand the problem. 2014-12-29 19:36 GMT+03:00 hjl.tools at gmail dot com <gcc-bugzi...@gcc.gnu.org>: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64434 > > --- Comment #7 from H.J. Lu <hjl.tools at gmail dot com> --- > r216728 generates much longer code sequences. Where does it come from? > Does -m64 also generate longer code sequences? > > -- > You are receiving this mail because: > You reported the bug.
