On 11/10/15 21:30, Aurelien Jarno wrote: > (sorry for the late answer) > > On 2015-08-26 14:12, Petar Jovanovic wrote: >> From: Petar Jovanovic <petar.jovano...@imgtec.com> >> >> Instructions recip.{s|d} and rsqrt.{s|d} do not require 64-bit FPU neither >> they require any particular mode for its FPU. This patch removes the checks >> that may break a program that uses these instructions. > > That is correct. That said these instructions do require at least a > MIPS32R2 or a MIPS64R1 CPU. I guess we should add these checks now that > check_cop1x do not guard them anymore.
I suspect that this might too restrictive if we take into account also legacy processors. As far as I know these instructions were already present in MIPS IV implementations. I think it'll be safer if for the pre-MIPS32R2 and pre-MIPS64R1 CPUs we keep the check_cop1x. (actually I'm not certain if check_cop1x is correct, but at least we aren't relaxing the previous restrictions too much). Regards, Leon