Cache the set of EH_RETURN_DATA_REGNOs

While reviewing Andrew's fix for PR114843, it seemed like it would
be convenient to have a HARD_REG_SET of EH_RETURN_DATA_REGNOs.
This patch adds one and uses it to simplify a couple of use sites.

Tested on aarch64-linux-gnu & x86_64-linux-gnu.  OK to install?

Richard


gcc/
	* hard-reg-set.h (target_hard_regs::x_eh_return_data_regs): New field.
	(eh_return_data_regs): New macro.
	* reginfo.cc (init_reg_sets_1): Initialize x_eh_return_data_regs.
	* df-scan.cc (df_get_exit_block_use_set): Use it.
	* ira-lives.cc (process_out_of_region_eh_regs): Likewise.
---
 gcc/df-scan.cc     |  8 +-------
 gcc/hard-reg-set.h |  5 +++++
 gcc/ira-lives.cc   | 10 ++--------
 gcc/reginfo.cc     | 10 ++++++++++
 4 files changed, 18 insertions(+), 15 deletions(-)

On Tue, May 21, 2024 at 11:03 AM Richard Sandiford
<richard.sandiford@arm.com> wrote:
>
> While reviewing Andrew's fix for PR114843, it seemed like it would
> be convenient to have a HARD_REG_SET of EH_RETURN_DATA_REGNOs.
> This patch adds one and uses it to simplify a couple of use sites.
>
> Tested on aarch64-linux-gnu & x86_64-linux-gnu.  OK to install?

OK

> Richard
>
>
> gcc/
>         * hard-reg-set.h (target_hard_regs::x_eh_return_data_regs): New field.
>         (eh_return_data_regs): New macro.
>         * reginfo.cc (init_reg_sets_1): Initialize x_eh_return_data_regs.
>         * df-scan.cc (df_get_exit_block_use_set): Use it.
>         * ira-lives.cc (process_out_of_region_eh_regs): Likewise.
> ---
>  gcc/df-scan.cc     |  8 +-------
>  gcc/hard-reg-set.h |  5 +++++
>  gcc/ira-lives.cc   | 10 ++--------
>  gcc/reginfo.cc     | 10 ++++++++++
>  4 files changed, 18 insertions(+), 15 deletions(-)
>
> diff --git a/gcc/df-scan.cc b/gcc/df-scan.cc
> index 1bade2cd71e..c8ab3c09cee 100644
> --- a/gcc/df-scan.cc
> +++ b/gcc/df-scan.cc
> @@ -3702,13 +3702,7 @@ df_get_exit_block_use_set (bitmap exit_block_uses)
>
>    /* Mark the registers that will contain data for the handler.  */
>    if (reload_completed && crtl->calls_eh_return)
> -    for (i = 0; ; ++i)
> -      {
> -       unsigned regno = EH_RETURN_DATA_REGNO (i);
> -       if (regno == INVALID_REGNUM)
> -         break;
> -       bitmap_set_bit (exit_block_uses, regno);
> -      }
> +    IOR_REG_SET_HRS (exit_block_uses, eh_return_data_regs);
>
>  #ifdef EH_RETURN_STACKADJ_RTX
>    if ((!targetm.have_epilogue () || ! epilogue_completed)
> diff --git a/gcc/hard-reg-set.h b/gcc/hard-reg-set.h
> index 8c1d1512ca2..340eb425c10 100644
> --- a/gcc/hard-reg-set.h
> +++ b/gcc/hard-reg-set.h
> @@ -421,6 +421,9 @@ struct target_hard_regs {
>       with the local stack frame are safe, but scant others.  */
>    HARD_REG_SET x_regs_invalidated_by_call;
>
> +  /* The set of registers that are used by EH_RETURN_DATA_REGNO.  */
> +  HARD_REG_SET x_eh_return_data_regs;
> +
>    /* Table of register numbers in the order in which to try to use them.  */
>    int x_reg_alloc_order[FIRST_PSEUDO_REGISTER];
>
> @@ -485,6 +488,8 @@ extern struct target_hard_regs *this_target_hard_regs;
>  #define call_used_or_fixed_regs \
>    (regs_invalidated_by_call | fixed_reg_set)
>  #endif
> +#define eh_return_data_regs \
> +  (this_target_hard_regs->x_eh_return_data_regs)
>  #define reg_alloc_order \
>    (this_target_hard_regs->x_reg_alloc_order)
>  #define inv_reg_alloc_order \
> diff --git a/gcc/ira-lives.cc b/gcc/ira-lives.cc
> index e07d3dc3e89..958eabb9708 100644
> --- a/gcc/ira-lives.cc
> +++ b/gcc/ira-lives.cc
> @@ -1260,14 +1260,8 @@ process_out_of_region_eh_regs (basic_block bb)
>        for (int n = ALLOCNO_NUM_OBJECTS (a) - 1; n >= 0; n--)
>         {
>           ira_object_t obj = ALLOCNO_OBJECT (a, n);
> -         for (int k = 0; ; k++)
> -           {
> -             unsigned int regno = EH_RETURN_DATA_REGNO (k);
> -             if (regno == INVALID_REGNUM)
> -               break;
> -             SET_HARD_REG_BIT (OBJECT_CONFLICT_HARD_REGS (obj), regno);
> -             SET_HARD_REG_BIT (OBJECT_TOTAL_CONFLICT_HARD_REGS (obj), regno);
> -           }
> +         OBJECT_CONFLICT_HARD_REGS (obj) |= eh_return_data_regs;
> +         OBJECT_TOTAL_CONFLICT_HARD_REGS (obj) |= eh_return_data_regs;
>         }
>      }
>  }
> diff --git a/gcc/reginfo.cc b/gcc/reginfo.cc
> index a0baeb90e12..73121365c47 100644
> --- a/gcc/reginfo.cc
> +++ b/gcc/reginfo.cc
> @@ -420,6 +420,16 @@ init_reg_sets_1 (void)
>         }
>      }
>
> +  /* Recalculate eh_return_data_regs.  */
> +  CLEAR_HARD_REG_SET (eh_return_data_regs);
> +  for (i = 0; ; ++i)
> +    {
> +      unsigned int regno = EH_RETURN_DATA_REGNO (i);
> +      if (regno == INVALID_REGNUM)
> +       break;
> +      SET_HARD_REG_BIT (eh_return_data_regs, regno);
> +    }
> +
>    memset (have_regs_of_mode, 0, sizeof (have_regs_of_mode));
>    memset (contains_reg_of_mode, 0, sizeof (contains_reg_of_mode));
>    for (m = 0; m < (unsigned int) MAX_MACHINE_MODE; m++)
> --
> 2.25.1
>