Re: [Psyco-devel] More float advice needed

[Tim H. <tim...@ie...>]

Hello Armin,

Thanks for the tips. That was enough for me to get this working.

I also modified psyco_generic_call to allow CfNoReturnValue with CfPure. I
just had it always return CC_ALWAYS_TRUE. I did this because some of my
cimpl_XXX functions have no return values. However, if you think
CfNoReturnValue should not be allowed with CfPure, I can instead have the
cimpl_XXX function return dummy values. I think this leaves only 'r'
disallowed with CfPure, but since 'r' seems to be explicitly run time, that
seems not to be a problem.

With these changes, the following function (a ripoff of f1()) runs a bit
over ten times faster than stock python:

def f10(n):
    "Arbitrary test function."
    i = 0.0
    x = 1.0
    while i<n:
        j = ZERO_F
        while j<=i:
            j = j + 1.0
            x = x + i*j
        i = i + 1.0
    return x

The following silly function now runs ever faster with increasing n, now
that everything is compiled away:

def f10(n):
    i = 0
    while i < n:
        x = 5. + 7.
        i = i + 1

I've had it up to over 100X faster than stock python with large enough n.

Anyway, it's all very cool. Thanks for writing this Armin! I'll post patches
real soon now.

-tim


> Hello Tim,
>
> On Thu, 10 Jan 2002, Tim Hochberg wrote:
> > Does that mean modifying psyco_call_var (AKA glue_call_var)? If so,
brrrr!
> > That's a bit out of my comfort zone right now. If not, could you give me
> > some hints on what would need to change in psyco_generic_call to get
this to
> > work?
>
> No, all you need to modify is psyco_generic_call(). psyco_call_var() will
> just call the C function directly by passing it the arguments listed in
> the 'args' array. For example, to call a function with signature (double,
> double, double*), the args array must contain 4 values for the first two
> doubles, and a 5th value which is a pointer to a 8-bytes buffer.
>
> In other words, in psyco_generic_call(), in the CfPure case, for any 'a'
> or 'A' arguments, you must allocate a buffer whose size is given by
> ((vinfo_array_t*) args[i])->count and put it in args[i]. After
> psyco_call_var(), you get the output of the C function in the buffers;
> they must be put back into the vinfo_array_t's, as compile-time-known
> vinfo_t's: for each 'a' argument, fill the corresponding vinfo_array_t
> with as many 'vinfo_new(CompileTime_New(...))' as the length of the array
> dictates; for each 'A' argument, you must also obtain a reference on the
> returned Python objects by using 'vinfo_new(CompileTime_NewSk(sk_new(...,
> SkFlagPyObj)))'.
>
>
> Hope this helps,
>
> Armin.
>