Re: [Qemu-devel] [PATCH 03/16] tcg: Propagate args to op->args in tcg.c

[Richard Henderson]

On 06/26/2017 08:02 AM, Alex Bennée wrote:
> >   #if TARGET_LONG_BITS > TCG_TARGET_REG_BITS
> > -                a = ((target_ulong)args[i * 2 + 1] << 32) | args[i * 2];
> > +                a = deposit64(op->args[i * 2], 32, 32, op->args[i * 2
> >               + 1]);
>
> It doesn't now but should be assert against us overflowing the args
> buffer here when dealing with encoded data? Or should it have faulted
> when planting the ops?

Statically checked via preprocessor in tcg/tcg-op.h:

#elif TARGET_INSN_START_WORDS == 3
...
#else
# error "Unhandled number of operands to insn_start"
#endif

which maxes out at 6 host arguments, which is less than MAX_OPC_PARAM.


r~