RFA[powerpc]: patch to fix PR79916

[Jakub Jelinek]

On Fri, Apr 13, 2018 at 03:29:47PM -0400, Vladimir Makarov wrote:
> Â  The attached patch fixes
> 
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79916
> 
>   The PR is about LRA cycling on some tests when SD data are used.  The
> problem was in that actual assigned reg to pseudo was not in the pseudo
> preferred class and this resulted in wrong generated code which LRA tried to
> change again and again.
> 
> Â  The patch was successfully bootstrapped and tested on ppc64 (gcc110).
> 
> Â  Is it ok to commit?

I have just formatting nits and will defer the actual review to the PowerPC
maintainers.  The nit is that all the lines are too long.
Not sure if
	  if (reg_renumber[regno] >= 0)
	    regno = reg_renumber[regno];
	  else
	    regno = cl == NO_REGS ? -1 : ira_class_hard_regs[cl][1];
or
	  regno = (reg_renumber[regno] >= 0
		   ? reg_renumber[regno]
		   : cl == NO_REGS ? -1 : ira_class_hard_regs[cl][1]);
is better, the latter is perhaps more compact.

> --- config/rs6000/rs6000.c	(revision 259330)
> +++ config/rs6000/rs6000.c	(working copy)
> @@ -10610,7 +10610,7 @@ rs6000_emit_move (rtx dest, rtx source,
>        if (regno >= FIRST_PSEUDO_REGISTER)
>  	{
>  	  cl = reg_preferred_class (regno);
> -	  regno = cl == NO_REGS ? -1 : ira_class_hard_regs[cl][1];
> +	  regno = reg_renumber[regno] >= 0 ? reg_renumber[regno] : cl == NO_REGS ? -1 : ira_class_hard_regs[cl][1];
>  	}
>        if (regno >= 0 && ! FP_REGNO_P (regno))
>  	{
> @@ -10635,7 +10635,7 @@ rs6000_emit_move (rtx dest, rtx source,
>  	{
>  	  cl = reg_preferred_class (regno);
>  	  gcc_assert (cl != NO_REGS);
> -	  regno = ira_class_hard_regs[cl][0];
> +	  regno = reg_renumber[regno] >= 0 ? reg_renumber[regno] : ira_class_hard_regs[cl][0];
>  	}
>        if (FP_REGNO_P (regno))
>  	{
> @@ -10664,7 +10664,7 @@ rs6000_emit_move (rtx dest, rtx source,
>        if (regno >= FIRST_PSEUDO_REGISTER)
>  	{
>  	  cl = reg_preferred_class (regno);
> -	  regno = cl == NO_REGS ? -1 : ira_class_hard_regs[cl][0];
> +	  regno = reg_renumber[regno] >= 0 ? reg_renumber[regno] : cl == NO_REGS ? -1 : ira_class_hard_regs[cl][0];
>  	}
>        if (regno >= 0 && ! FP_REGNO_P (regno))
>  	{
> @@ -10689,7 +10689,7 @@ rs6000_emit_move (rtx dest, rtx source,
>  	{
>  	  cl = reg_preferred_class (regno);
>  	  gcc_assert (cl != NO_REGS);
> -	  regno = ira_class_hard_regs[cl][0];
> +	  regno = reg_renumber[regno] >= 0 ? reg_renumber[regno] : ira_class_hard_regs[cl][0];
>  	}
>        if (FP_REGNO_P (regno))
>  	{

	Jakub