Re: [PATCH 04/30] tcg/loongarch: Add generated instruction opcodes and encoding helpers

[WANG Xuerui]

Hi Philippe,

On 9/21/21 17:58, Philippe Mathieu-Daudé wrote:
> On 9/20/21 10:04, WANG Xuerui wrote:
> > Signed-off-by: WANG Xuerui <git@xen0n.name>
> > ---
> >   tcg/loongarch/tcg-insn-defs.c.inc | 1080 +++++++++++++++++++++++++++++
> >   1 file changed, 1080 insertions(+)
> >   create mode 100644 tcg/loongarch/tcg-insn-defs.c.inc
>
> > +static int32_t encode_dj_slots(LoongArchInsn opc, uint32_t d, 
> > uint32_t j)
> > +{
> Can we move the range check to the callee and avoid masking the values
> in the caller?
>
>        tcg_debug_assert(d < 0x20);
>        tcg_debug_assert(j < 0x20);

Making use of tcg_debug_assert would be rather nice, but in fact 
different instructions could have differently sized fields start from 
the same offset. Take the "bstrpick.w" and "bstrpick.d" instructions, 
they belong to DJUk5Um5 and DJUk6Um6 formats respectively; the "Uk5" and 
"Uk6" fields both start from the 10th bit but have different value 
ranges. So the range checks necessarily live in encoders for the 
individual formats.