Re: [PATCH 10/11] Fix LRA to handle multi-word eliminable registers

[Vladimir Makarov <vmakarov at redhat dot com>]

On 06/13/2018 02:58 PM, Dimitar Dimitrov wrote:
> From: Dimitar Dimitrov <dddimitrov@mm-sol.com>
>
> For some targets, Pmode != UNITS_PER_WORD. Take this into account
> when marking hard registers as being used.
>
> I tested C and C++ testsuits for x86_64 with and without this
> patch. There was no regression, i.e. gcc.sum and g++.sum matched
> exactly.
>
> gcc/ChangeLog:
>
> 2018-06-13  Dimitar Dimitrov  <dimitar@dinux.eu>
>
> 	* lra-eliminations.c (set_ptr_hard_reg_bits): New function.
> 	(update_reg_eliminate): Mark all spanning hw registers.
>
> gcc/testsuite/ChangeLog:
>
> 2018-06-13  Dimitar Dimitrov  <dimitar@dinux.eu>
>
> 	* gcc.target/pru/lra-framepointer-fragmentation-1.c: New test.
> 	* gcc.target/pru/lra-framepointer-fragmentation-2.c: New test.
>
> Cc: Vladimir Makarov <vmakarov@redhat.com>
> Cc: Peter Bergner <bergner@vnet.ibm.com>
> Cc: Kenneth Zadeck <zadeck@naturalbridge.com>
> Cc: Seongbae Park <seongbae.park@gmail.com>
> Signed-off-by: Dimitar Dimitrov <dddimitrov@mm-sol.com>
> ---
>   gcc/lra-eliminations.c                             | 14 ++++-
>   .../pru/lra-framepointer-fragmentation-1.c         | 33 ++++++++++++
>   .../pru/lra-framepointer-fragmentation-2.c         | 61 ++++++++++++++++++++++
>   3 files changed, 106 insertions(+), 2 deletions(-)
>   create mode 100644 gcc/testsuite/gcc.target/pru/lra-framepointer-fragmentation-1.c
>   create mode 100644 gcc/testsuite/gcc.target/pru/lra-framepointer-fragmentation-2.c
>
> diff --git a/gcc/lra-eliminations.c b/gcc/lra-eliminations.c
> index 21d8d5f8018..566cc2c8248 100644
> --- a/gcc/lra-eliminations.c
> +++ b/gcc/lra-eliminations.c
> @@ -1180,6 +1180,16 @@ spill_pseudos (HARD_REG_SET set)
>     bitmap_clear (&to_process);
>   }
>   
> +static void set_ptr_hard_reg_bits (HARD_REG_SET *hard_reg_set, int r)
> +{
> +  int w;
> +
> +  for (w = 0; w < GET_MODE_SIZE (Pmode); w += UNITS_PER_WORD, r++)
> +    {
> +	  SET_HARD_REG_BIT (*hard_reg_set, r);
> +    }
> +}
> +
The patch itself is ok but for uniformity I'd use

    for (int i = hard_regno_nregs (r, Pmode) - 1; i >= 0; i--)
      SET_HARD_REG_BIT (*hard_reg_set, r + i);


Approved with the above change.