Patch: fix compress_float_constant heuristics

[Dale Johannesen]

On Jul 10, 2005, at 8:57 PM, David Edelsohn wrote:

> 	* config/rs6000.c (rs6000_rtx_cost):  Adjust FLOAT_EXTEND cost.
>
> +    case FLOAT_EXTEND:
> +      /* For memory references, float-to-double conversion is free. */
> +      if (mode == DFmode
> +        && GET_CODE (XEXP (x, 0)) == MEM
> +	 && GET_MODE (XEXP (x, 0)) == SFmode)
> +	*total = 0;
> +      else
> +        *total = rs6000_cost->fp;
> +      return false;
>
> 	FLOAT_EXTEND of a register also is free if the register allocator
> can be convinced to use the same register.

Yes, but you can't tell that here.  If you want to make the more
aggressive assumption, fine with me.

> And what other mode would be
> the source for float_extend:DF other than SFmode?

I know, I thought it was clearer this way.

> 	if (mode == DFmode)
>
> should suffice.

OK.

> 	Also, it looks like there is an indentation problem on one of the
> two *total = lines.  Tab versus spaces?

Yes, one is tab, one is 8 spaces.  People keep saying there's some 
standard
about this, but I've never found anything on the coding style pages....