Re: [PATCH 4/5] Partial revert of r243782 to restore previous behavior

[Vladimir Makarov <vmakarov at redhat dot com>]

On 02/07/2017 09:08 AM, Matthew Fortune wrote:
> Hi,
>
> This patch partially reverts r243782 where a return false was added
> expecting it to be a no-op.  Detailed inspection shows this was not
> true.  Despite no bug being identified following the change, removing
> the early return is likely to be safer than leaving it in place.
>
> This is supported by the discussion here:
> https://gcc.gnu.org/ml/gcc/2017-02/msg00007.html
OK for the trunk.  Matt, thank you very much for efforts to clean 
simplify_operand_subreg up.
> gcc/
> 	* lra-constraints.c (simplify_operand_subreg): Remove early
> 	return false.
> ---
>   gcc/lra-constraints.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/gcc/lra-constraints.c b/gcc/lra-constraints.c
> index 484a70d..0b7ae34 100644
> --- a/gcc/lra-constraints.c
> +++ b/gcc/lra-constraints.c
> @@ -1607,7 +1607,8 @@ simplify_operand_subreg (int nop, machine_mode reg_mode)
>   	 the memory.  Typical case is when the index scale should
>   	 correspond the memory.  */
>         *curr_id->operand_loc[nop] = operand;
> -      return false;
> +      /* Do not return false here as the MEM_P (reg) will be processed
> +	 later in this function.  */
>       }
>     else if (REG_P (reg) && REGNO (reg) < FIRST_PSEUDO_REGISTER)
>       {