On Fri, Oct 14, 2016 at 12:44 AM, Yongbok Kim <yongbok....@imgtec.com> wrote: > > > On 13/10/2016 08:10, Heiher wrote: >> From: Heiher <wa...@lemote.com> >> >> Needed to emit FPU exception on Loongson multimedia instructions >> executing if Status:CU1 is clear. or FPR changes may be missed >> on Linux. >> >> Signed-off-by: Heiher <wa...@lemote.com> >> Signed-off-by: Fuxin Zhang <zhan...@lemote.com> >> --- >> target-mips/translate.c | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/target-mips/translate.c b/target-mips/translate.c >> index 139f249..b87a09b 100644 >> --- a/target-mips/translate.c >> +++ b/target-mips/translate.c >> @@ -3871,6 +3871,7 @@ static void gen_loongson_multimedia(DisasContext *ctx, >> int rd, int rs, int rt) >> break; >> } >> >> + check_cp1_enabled(ctx); > > Isn't it also required to check Status.CU2 bit? I guess the Loongson > Multimedia instructions was implemented as the Cop2? Please correct me if I > am wrong with this.
I don't think the Loongson CPUs have real coprocessor 2 although these multimedia instructions are encoding as Cp2. Similar to MSA, these instructions reusing 64-bit FPRs. In fact, The older Loongson CPUs emit Cp2 unusable exception, so a cp2 hook is needed to combine FPU and Cp2 in kernel. In new revision, Cp1 exception is emitted. > >> gen_load_fpr64(ctx, t0, rs); >> gen_load_fpr64(ctx, t1, rt); >> >> > > Regards, > Yongbok -- Best regards! Heiher http://hev.cc
