LRA assign same hard register with live range overlapped pseduos

Vladimir Makarov vmakarov@redhat.com
Tue Apr 23 00:05:00 GMT 2013


On 13-04-22 2:26 AM, Shiva Chen wrote:
> Hi, Vladimir
>
> I write the new patch as your suggestion.
> Could you help me to check is there something missing ?
I think there is one more place to use lra_assign_reg_val:

lra.c::lra_create_new_reg

Please add the code and right changelog entry for the patch and you can 
commit the patch into trunk.

Thanks, Shiva.
> Thanks, Shiva
>
>   gcc/lra-assigns.c      |   12 +++++++-----
>   gcc/lra-constraints.c  |    5 ++---
>   gcc/lra-eliminations.c |   10 ++++++++--
>   gcc/lra-int.h          |   33 +++++++++++++++++++++++++++++++++
>   gcc/lra.c              |    1 +
>   5 files changed, 51 insertions(+), 10 deletions(-)
>
> diff --git a/gcc/lra-assigns.c b/gcc/lra-assigns.c
> index b204513..3f8a899 100644
> --- a/gcc/lra-assigns.c
> +++ b/gcc/lra-assigns.c
> @@ -448,7 +448,7 @@ find_hard_regno_for (int regno, int *cost, int
> try_only_hard_regno)
>     int hr, conflict_hr, nregs;
>     enum machine_mode biggest_mode;
>     unsigned int k, conflict_regno;
> -  int val, biggest_nregs, nregs_diff;
> +  int offset, val, biggest_nregs, nregs_diff;
>     enum reg_class rclass;
>     bitmap_iterator bi;
>     bool *rclass_intersect_p;
> @@ -508,9 +508,10 @@ find_hard_regno_for (int regno, int *cost, int
> try_only_hard_regno)
>   #endif
>     sparseset_clear_bit (conflict_reload_and_inheritance_pseudos, regno);
>     val = lra_reg_info[regno].val;
> +  offset = lra_reg_info[regno].offset;
>     CLEAR_HARD_REG_SET (impossible_start_hard_regs);
>     EXECUTE_IF_SET_IN_SPARSESET (live_range_hard_reg_pseudos, conflict_regno)
> -    if (val == lra_reg_info[conflict_regno].val)
> +    if (lra_reg_val_equal_p (conflict_regno, val, offset))
>         {
>          conflict_hr = live_pseudos_reg_renumber[conflict_regno];
>          nregs = (hard_regno_nregs[conflict_hr]
> @@ -538,7 +539,7 @@ find_hard_regno_for (int regno, int *cost, int
> try_only_hard_regno)
>         }
>     EXECUTE_IF_SET_IN_SPARSESET (conflict_reload_and_inheritance_pseudos,
>                                 conflict_regno)
> -    if (val != lra_reg_info[conflict_regno].val)
> +    if (!lra_reg_val_equal_p (conflict_regno, val, offset))
>         {
>          lra_assert (live_pseudos_reg_renumber[conflict_regno] < 0);
>          if ((hard_regno
> @@ -1007,7 +1008,7 @@
> setup_live_pseudos_and_spill_after_risky_transforms (bitmap
>   {
>     int p, i, j, n, regno, hard_regno;
>     unsigned int k, conflict_regno;
> -  int val;
> +  int val, offset;
>     HARD_REG_SET conflict_set;
>     enum machine_mode mode;
>     lra_live_range_t r;
> @@ -1050,8 +1051,9 @@
> setup_live_pseudos_and_spill_after_risky_transforms (bitmap
>         COPY_HARD_REG_SET (conflict_set, lra_no_alloc_regs);
>         IOR_HARD_REG_SET (conflict_set, lra_reg_info[regno].conflict_hard_regs);
>         val = lra_reg_info[regno].val;
> +      offset = lra_reg_info[regno].offset;
>         EXECUTE_IF_SET_IN_SPARSESET (live_range_hard_reg_pseudos, conflict_regno)
> -       if (val != lra_reg_info[conflict_regno].val
> +       if (!lra_reg_val_equal_p (conflict_regno, val, offset)
>              /* If it is multi-register pseudos they should start on
>                 the same hard register.  */
>              || hard_regno != reg_renumber[conflict_regno])
> diff --git a/gcc/lra-constraints.c b/gcc/lra-constraints.c
> index e3b4add..2a72aef 100644
> --- a/gcc/lra-constraints.c
> +++ b/gcc/lra-constraints.c
> @@ -704,7 +704,7 @@ match_reload (signed char out, signed char *ins,
> enum reg_class goal_class,
>               pseudos still live where reload pseudos dies.  */
>            if (REG_P (in_rtx) && (int) REGNO (in_rtx) < lra_new_regno_start
>                && find_regno_note (curr_insn, REG_DEAD, REGNO (in_rtx)))
> -           lra_reg_info[REGNO (reg)].val = lra_reg_info[REGNO (in_rtx)].val;
> +           lra_assign_reg_val (REGNO (in_rtx), REGNO (reg));
>          }
>         else
>          {
> @@ -733,8 +733,7 @@ match_reload (signed char out, signed char *ins,
> enum reg_class goal_class,
>                    && GET_MODE (subreg_reg) == outmode
>                    && SUBREG_BYTE (in_rtx) == SUBREG_BYTE (new_in_reg)
>                    && find_regno_note (curr_insn, REG_DEAD, REGNO (subreg_reg)))
> -               lra_reg_info[REGNO (reg)].val
> -                 = lra_reg_info[REGNO (subreg_reg)].val;
> +               lra_assign_reg_val (REGNO (subreg_reg), REGNO (reg));
>              }
>          }
>       }
> diff --git a/gcc/lra-eliminations.c b/gcc/lra-eliminations.c
> index 9df0bae..0e75cc2 100644
> --- a/gcc/lra-eliminations.c
> +++ b/gcc/lra-eliminations.c
> @@ -1124,8 +1124,14 @@ update_reg_eliminate (bitmap insns_with_changed_offsets)
>     setup_elimination_map ();
>     for (ep = reg_eliminate; ep < &reg_eliminate[NUM_ELIMINABLE_REGS]; ep++)
>       if (elimination_map[ep->from] == ep && ep->previous_offset != ep->offset)
> -      bitmap_ior_into (insns_with_changed_offsets,
> -                      &lra_reg_info[ep->from].insn_bitmap);
> +      {
> +       bitmap_ior_into (insns_with_changed_offsets,
> +                        &lra_reg_info[ep->from].insn_bitmap);
> +
> +       /* Update offset when the eliminate offset have been changed.  */
> +       lra_set_up_reg_val (lra_reg_info[ep->from].val,
> +                           ep->offset - ep->previous_offset);
> +      }
>   }
>
>   /* Initialize the table of hard registers to eliminate.
> diff --git a/gcc/lra-int.h b/gcc/lra-int.h
> index 98f2ff7..69f8f8a 100644
> --- a/gcc/lra-int.h
> +++ b/gcc/lra-int.h
> @@ -116,6 +116,8 @@ struct lra_reg
>     /* Value holding by register.         If the pseudos have the same value
>        they do not conflict.  */
>     int val;
> +  /* Offset from relative eliminate register to pesudo reg.  */
> +  int offset;
>     /* These members are set up in lra-lives.c and updated in
>        lra-coalesce.c.  */
>     /* The biggest size mode in which each pseudo reg is referred in
> @@ -439,6 +441,37 @@ lra_get_insn_recog_data (rtx insn)
>     return lra_set_insn_recog_data (insn);
>   }
> +/* Update offset from eliminate register to pseduo i.  */
> +static inline void
> +lra_set_up_reg_val (int val, int offset)
> +{
> +  int i;
> +
> +  for (i = FIRST_PSEUDO_REGISTER; i < max_reg_num (); i++)
> +    {
> +      if (lra_reg_info[i].val == val)
> +        lra_reg_info[i].offset += offset;
> +    }
> +}
> +
> +/* Return true if register content are equal.  */
> +static inline bool
> +lra_reg_val_equal_p (int regno, int val, int offset)
> +{
> +  if (lra_reg_info[regno].val == val
> +      && lra_reg_info[regno].offset == offset)
> +    return true;
> +
> +  return false;
> +}
> +
> +/* Assign register content record.  */
> +static inline void
> +lra_assign_reg_val (int from, int to)
> +{
> +  lra_reg_info[to].val = lra_reg_info[from].val;
> +  lra_reg_info[to].offset = lra_reg_info[from].offset;
> +}
>   struct target_lra_int
> diff --git a/gcc/lra.c b/gcc/lra.c
> index 9df24b5..4c06a0c 100644
> --- a/gcc/lra.c
> +++ b/gcc/lra.c
> @@ -1392,6 +1392,7 @@ initialize_lra_reg_info_element (int i)
>     lra_reg_info[i].last_reload = 0;
>     lra_reg_info[i].restore_regno = -1;
>     lra_reg_info[i].val = get_new_reg_value ();
> +  lra_reg_info[i].offset = 0;
>     lra_reg_info[i].copies = NULL;
>   }
>
>



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