[ARM/FDPIC v2 07/21] [ARM] FDPIC: Avoid saving/restoring r9 on stack since it is RO

[Kyrill Tkachov]

Hi Christophe,

On 13/07/18 17:11, christophe.lyon@st.com wrote:
> From: Christophe Lyon <christophe.lyon@linaro.org>
>
> 2018-XX-XX  Christophe Lyon  <christophe.lyon@st.com>
>         Mickaël Guêné <mickael.guene@st.com>
>
>         gcc/
>         * config/arm/arm.c (arm_compute_save_reg0_reg12_mask): Handle
>         FDPIC.
>         (thumb1_compute_save_core_reg_mask): Likewise.
>
> Change-Id: Ib534cf91704cdc740867b46a8fe45fda27894562
>
> diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
> index 44c3b08..c9f391b 100644
> --- a/gcc/config/arm/arm.c
> +++ b/gcc/config/arm/arm.c
> @@ -19486,7 +19486,7 @@ arm_compute_save_reg0_reg12_mask (void)
>
>        /* Also save the pic base register if necessary.  */
>        if (flag_pic
> -         && !TARGET_SINGLE_PIC_BASE
> +         && !TARGET_SINGLE_PIC_BASE && !TARGET_FDPIC
>            && arm_pic_register != INVALID_REGNUM
>            && crtl->uses_pic_offset_table)
>          save_reg_mask |= 1 << PIC_OFFSET_TABLE_REGNUM;
> @@ -19520,7 +19520,7 @@ arm_compute_save_reg0_reg12_mask (void)
>        /* If we aren't loading the PIC register,
>           don't stack it even though it may be live.  */
>        if (flag_pic
> -         && !TARGET_SINGLE_PIC_BASE
> +         && !TARGET_SINGLE_PIC_BASE && !TARGET_FDPIC
>            && arm_pic_register != INVALID_REGNUM
>            && (df_regs_ever_live_p (PIC_OFFSET_TABLE_REGNUM)
>                || crtl->uses_pic_offset_table))
> @@ -19689,7 +19689,7 @@ thumb1_compute_save_core_reg_mask (void)
>      mask |= 1 << HARD_FRAME_POINTER_REGNUM;
>
>    if (flag_pic
> -      && !TARGET_SINGLE_PIC_BASE
> +      && !TARGET_SINGLE_PIC_BASE && !TARGET_FDPIC
>        && arm_pic_register != INVALID_REGNUM
>        && crtl->uses_pic_offset_table)
>      mask |= 1 << PIC_OFFSET_TABLE_REGNUM;

Is this change necessary? FDPIC is only supported for Armv7 onwards, so the Thumb1 path shouldn't be called?

Thanks,
Kyrill

> -- 
> 2.6.3
>