Re: [PATCH] Fix passing double float complex arguments in sparc64

[Mark Kettenis <mark.kettenis@xs4all.nl>]

> From: jose.marchesi@oracle.com (Jose E. Marchesi)
> Date: Tue, 15 Oct 2013 17:57:27 +0200
> 
> Hi.
> 
> Double float complex objects are not 16-byte aligned in either gcc or
> solaris studio.  This patch makes gdb to not align double float complex
> arguments in the dummy frame when calling a function.
> 
> This makes all the tests in gdb.base/varargs.exp to pass in
> sparc64-*-linux-gnu.
> 
> 2013-10-15  Jose E. Marchesi  <jose.marchesi@oracle.com>
> 
>         * sparc64-tdep.c (sparc64_store_arguments): Do not align complex
>         double float arguments to 16-byte.

Hi Jose,

A bit of digging around seems to confirm that we shouldn't align
double complex variables.  However, I think that with your diff we're
still not storing things in the right registers.

Mark

> Index: sparc64-tdep.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/sparc64-tdep.c,v
> retrieving revision 1.62
> diff -u -r1.62 sparc64-tdep.c
> --- sparc64-tdep.c	1 Jan 2013 06:32:51 -0000	1.62
> +++ sparc64-tdep.c	15 Oct 2013 15:46:25 -0000
> @@ -831,7 +831,7 @@
>                   quad-aligned, and thus a hole might be introduced
>                   into the parameter array to force alignment."  Skip
>                   an element if necessary.  */
> -	      if (num_elements % 2)
> +	      if ((num_elements % 2) && sparc64_16_byte_align_p (type))
>  		num_elements++;
>  	    }
>  	  else
> @@ -913,7 +913,7 @@
>  	  /* Floating arguments.  */
>  	  if (len == 16)
>  	    {
> -	      if (element % 2)
> +	      if ((element % 2) && sparc64_16_byte_align_p (type))
>  		element++;
>  	      if (element < 16)
>  		regnum = SPARC64_Q0_REGNUM + element / 2;
> @@ -961,7 +961,7 @@
>  	    }
>  	  else if (regnum >= SPARC64_Q0_REGNUM && regnum <= SPARC64_Q8_REGNUM)
>  	    {
> -	      gdb_assert (element < 5);
> +	      gdb_assert (element < 6);
>  	      regnum = SPARC_O0_REGNUM + element;
>  	      regcache_cooked_write (regcache, regnum, valbuf);
>  	      regcache_cooked_write (regcache, regnum + 1, valbuf + 8);
>