From: Richard Henderson <r...@redhat.com> Date: Fri, 30 Sep 2011 14:03:52 -0700
> (3) Use optimize-mode-switching to minimize the number of changes > to the global state. This includes the use of SIAM vs %fsr, > especially when a subroutine call could have changed the > global rounding mode. Indeed, and I incidentally took a look at the mode switching optimization framework and it appears that I could use it for providing insn patterns for 'rint' and friends like i386 does. > All of which is a lot of work. > >> +(define_insn "bmask<P:mode>_vis" >> + [(set (match_operand:P 0 "register_operand" "=r") >> + (plus:P (match_operand:P 1 "register_operand" "rJ") >> + (match_operand:P 2 "register_operand" "rJ"))) >> + (clobber (reg:SI GSR_REG))] >> + "TARGET_VIS2" >> + "bmask\t%r1, %r2, %0" >> + [(set_attr "type" "array")]) > > I think this is wrong. I think you want to model this as ... >> +(define_insn "bshuffle<V64I:mode>_vis" >> + [(set (match_operand:V64I 0 "register_operand" "=e") >> + (unspec:V64I [(match_operand:V64I 1 "register_operand" "e") >> + (match_operand:V64I 2 "register_operand" "e")] >> + UNSPEC_BSHUFFLE)) >> + (use (reg:SI GSR_REG))] > > Better to push the use of the GSR_REG into the unspec, and not leave > it separate in the parallel. Thanks Richard, I'll fix these up. In general, the GSR tracking needs a bit more work.
