Re: PATCH: PR tree-optimization/60024: global-buffer-overflow in init_regs_for_mode

[Andrey Belevantsev <abel at ispras dot ru>]

Hello,

On 01.02.2014 19:16, H.J. Lu wrote:
> Hi,
>
> init_regs_for_mode accesses global_regs before checking if regno is OK
> for a mode, which leads to buffer overflow.  This patch moves
> HARD_REGNO_MODE_OK for checking global_regs.  There is no functional
> change.  OK for trunk?

This is fine, you'd need to change tree-optimization/60024 to 
rtl-optimization/60024 in the ChangeLog.  Thanks for doing this.

Yours,
Andrey

> Thanks.
>
>
> H.J.
> ---
> 2014-02-01  H.J. Lu  <hongjiu.lu@intel.com>
>
> 	PR tree-optimization/60024
> 	* sel-sched.c (init_regs_for_mode): Check if mode is OK first.
>
> diff --git a/gcc/sel-sched.c b/gcc/sel-sched.c
> index ad4a0aa..7b1a183 100644
> --- a/gcc/sel-sched.c
> +++ b/gcc/sel-sched.c
> @@ -1116,9 +1116,16 @@ init_regs_for_mode (enum machine_mode mode)
>
>     for (cur_reg = 0; cur_reg < FIRST_PSEUDO_REGISTER; cur_reg++)
>       {
> -      int nregs = hard_regno_nregs[cur_reg][mode];
> +      int nregs;
>         int i;
>
> +      /* See whether it accepts all modes that occur in
> +         original insns.  */
> +      if (! HARD_REGNO_MODE_OK (cur_reg, mode))
> +        continue;
> +
> +      nregs = hard_regno_nregs[cur_reg][mode];
> +
>         for (i = nregs - 1; i >= 0; --i)
>           if (fixed_regs[cur_reg + i]
>                   || global_regs[cur_reg + i]
> @@ -1140,11 +1147,6 @@ init_regs_for_mode (enum machine_mode mode)
>         if (i >= 0)
>           continue;
>
> -      /* See whether it accepts all modes that occur in
> -         original insns.  */
> -      if (! HARD_REGNO_MODE_OK (cur_reg, mode))
> -        continue;
> -
>         if (HARD_REGNO_CALL_PART_CLOBBERED (cur_reg, mode))
>           SET_HARD_REG_BIT (sel_hrd.regs_for_call_clobbered[mode],
>                             cur_reg);