From mboxrd@z Thu Jan  1 00:00:00 1970
From: Weiwen Liu <liu@hepvms.physics.yale.edu>
To: rth@cygnus.com
Cc: egcs@cygnus.com
Subject: Re: complex support on alpha
Date: Thu, 02 Oct 1997 09:22:00 -0000
Message-id: <Pine.OSF.3.96.971002121841.30447A-100000@hepunix1.physics.yale.edu>
References: <199710020532.WAA16123@dot.cygnus.com>
X-SW-Source: 1997-10/msg00091.html

On Wed, 1 Oct 1997, Richard Henderson wrote:

> > The following patch  will calculate number of registers for
> > complex arguments correctly and compile complex-5.c correctly.
> 
> Well, it is enough to compile those examples properly, but it is
> not completely correct.  The problem is that complex numbers should
> be treated as two distinct arguments on Alpha, which affects padding
> of the arguments passed on the stack.
> 
> Have a look at the appended samples.  Note the lossage in the 
> handling of C in f1.  And the code generated for f2a and f2b
> should be identical wrt g+h/d.
> 
> It was a this point I got stuck myself.
> 
> 
> 
> r~
> 
> 
> 
> typedef __complex__ float FC;
> 
> FC f1(int odd, FC a, FC b, FC c)
> {
>   return a + b + c;
> }
> 
> FC f2a(float a, float b, float c, float d, float e, float f, float g, float h)
> {
>   return (a + c + e + g) + 1.0fi * (b + d + f + h);
> }
> 
> FC f2b(FC a, FC b, FC c, FC d)
> {
>   return a + b + c + d;
> }
> 

I am working on this.

I have a question concerning f1:
How do we pass C of f1?  Both real and imagine part on stack, or real on
register and imagine on stack?

Weiwen