patch for PR82444

[Vladimir Makarov]

On 02/01/2018 12:10 PM, Richard Sandiford wrote:
> Vladimir Makarov <vmakarov@redhat.com> writes:
> Not sure about the E_<mode>/genmodes reference here.  Isn't it simply
> "because it might be the mode a pseudo register"?
>
> Is it OK to expand the explanation a bit, as below?
>
Yes, it is OK.  It is a better explanation.  Thank you, Richard.
> 2018-02-01  Richard Sandiford  <richard.sandiford@linaro.org>
>
> gcc/
> 	* ira.c (ira_init_register_move_cost): Adjust comment.
>
> Index: gcc/ira.c
> ===================================================================
> --- gcc/ira.c	2018-02-01 17:09:45.998165072 +0000
> +++ gcc/ira.c	2018-02-01 17:09:46.150158481 +0000
> @@ -1578,8 +1578,10 @@ ira_init_register_move_cost (machine_mod
>     ira_assert (ira_register_move_cost[mode] == NULL
>   	      && ira_may_move_in_cost[mode] == NULL
>   	      && ira_may_move_out_cost[mode] == NULL);
> -  /* have_regs_of_mode[mode] might be false because it might be
> -     E_<mode> (see genmodes) of pseudo with <mode>.  */
> +  /* Note that we might be asked about the move costs of modes that
> +     cannot be stored in any hard register, for example if an inline
> +     asm tries to create a register operand with an impossible mode.
> +     We therefore can't assert have_regs_of_mode[mode] here.  */
>     for (cl1 = 0; cl1 < N_REG_CLASSES; cl1++)
>       for (cl2 = 0; cl2 < N_REG_CLASSES; cl2++)
>         {