[Bug target/16446] Irix calling conventions for complex numbers

["rsandifo at redhat dot com" <gcc-bugzilla at gcc dot gnu dot org>]

------- Additional Comments From rsandifo at redhat dot com  2004-07-29 06:04 -------
Subject: Re:  Irix calling conventions for complex numbers

"billingd at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org> writes:
> ------- Additional Comments From billingd at gcc dot gnu dot org  2004-07-28 23:59 -------
> Output from irix c99 foo.c test program
>
> 0 1
> 0 2
> 0 3
> 0 4
> 0 5
> 0 6
> 0 7
> 0 1.87053e-29
> 0 1
> 0 2
> 0 3
> 0 4
> 0 5
> 0 6
> 0 7
> 0 1.87053e-29

A bug!  I thought so!  The problem is that the real and imaginary
parts of complex float varargs are being passed in two separate GPRs:

    +------+------+
    |......| real |   GPR i
    +------+------+
    |......| imag |   GPR i+1
    +------+------+

but stack varargs are passed as follows:

    +------+------+
    | real | imag |   Stack word i
    +------+------+
    |......|......|   Stack word i+1
    +------+------+

What's more, it looks like MIPSpro's va_arg() expects neither of these,
and instead wants:

    +------+------+
    | real | imag |   Stack word i
    +------+------+

(i.e. with no word of padding).

Are you in a position to send this to SGI?  At the moment, it doesn't
look like we can hope for compatibility as far as complex floats go.
Complex doubles should be easy though.

> PS:  Richard, if you keep apologising for delays I will want my money back.

;) Point taken.

Richard


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16446