On 10/26/21 9:27 AM, Alex Bennée wrote:
I find this a bit magical. I couldn't find anything about TCGArg except
it's type:
typedef tcg_target_ulong TCGArg;
For an argument that contains a temp,
static inline TCGArg temp_arg(TCGTemp *ts)
{
return (uintptr_t)ts;
}
static inline TCGTemp *arg_temp(TCGArg a)
{
return (TCGTemp *)(uintptr_t)a;
}
i.e. the TCGArg is in fact a pointer.
so I'm not sure what to make of -1 in this case. I guess it just means
we never have a (sum == 0 && dest == a2) leg but it's not obvious
reading the fold code.
Indeed. The use of -1 goes back quite a ways. How about
#define NO_DEST temp_arg(NULL)
which will also fail to match in that expression?
r~
