Sisyphus <[EMAIL PROTECTED]> writes:
>Nick Ing-Simmons wrote:
>
>>>>
>>>>The sv_2mortal _IS_ needed in the
>>>>
>>>>void
>>>>my_xsub()
>>>>CODE:
>>>> {
>>>> ST(0) = sv_2mortal(newSVpv(string,strlen(string));
>>>> XSRETURN(1);
>>>> }
>>>>
>>>>case.
>>>>
>>>>But it is inserted for you SV * return case:
>>>>
>>>>{
>>>> RETVAL=newSV...;
>>>>}
>>>>#line 25 "Foo.c"
>>>> ST(0) = RETVAL;
>>>> sv_2mortal(ST(0));
>>>> }
>>>> XSRETURN(1);
>>>>}
>
>Case a:
>void my_func()
>I return a mortal SV via the stack.
>
>Case b:
>SV * my_func()
>I return an SV "directly".
>
>Let's see ... I'm being told that Case a and Case b are, wrt what gets
>executed, exactly the same (or very nearly so) .... right ?
Yes - there are some {} in different places but guts is essentially
identical.
>
>In both cases, a mortal SV is being returned via the stack ? - which
>would go some way to explaining the similar performance of both "cases" :-)
And the
Case c:
char *my_func()
uses the TARG style - which is different.
>
>What's 'Foo.c', btw ?
Output of xsubpp for a Foo.xs I slung together to see what got
generated.
