Re: RFA: Fix rtl-optimization/57425

[Richard Biener <richard dot guenther at gmail dot com>]

On Wed, Jun 19, 2013 at 9:58 PM, Joern Rennecke
<joern.rennecke@embecosm.com> wrote:
> Quoting Michael Matz <matz@suse.de>:
>
>> That's not good.  You now have different order of parameters between
>> anti_dependence and canon_anti_dependence.  That will be mightily
>> confusing, please instead change the caller.  Currently these predicates
>> take their arguments in the order of the corresponding instructions, that
>> should better be retained:
>>
>> true_dependence:  write-then-(depending)read
>> anti_dependence:  read-then-(clobbering)write
>> write_dependence: write-then-(clobbering)write
>
>
> All right, attached is the patch with the arguments in instruction-order.
> Again, bootstrapped/regtested on i686-pc-linux-gnu .

Ok.

Thanks,
Richard.

> 2013-06-19  Joern Rennecke <joern.rennecke@embecosm.com>
>
>         PR rtl-optimization/57425
>         PR rtl-optimization/57569
>         * alias.c (write_dependence_p): Remove parameters mem_mode and
>         canon_mem_addr.  Add parameters x_mode, x_addr and x_canonicalized.
>         Changed all callers.
>         (canon_anti_dependence): Get comments and semantics in sync.
>         Add parameter mem_canonicalized.  Changed all callers.
>         * rtl.h (canon_anti_dependence): Update prototype.
>
> Index: alias.c
> ===================================================================
> --- alias.c     (revision 200133)
> +++ alias.c     (working copy)
> @@ -156,8 +156,9 @@ static int insert_subset_children (splay
>  static alias_set_entry get_alias_set_entry (alias_set_type);
>  static bool nonoverlapping_component_refs_p (const_rtx, const_rtx);
>  static tree decl_for_component_ref (tree);
> -static int write_dependence_p (const_rtx, enum machine_mode, rtx,
> const_rtx,
> -                              bool, bool);
> +static int write_dependence_p (const_rtx,
> +                              const_rtx, enum machine_mode, rtx,
> +                              bool, bool, bool);
>
>  static void memory_modified_1 (rtx, const_rtx, void *);
>
> @@ -2555,20 +2556,22 @@ canon_true_dependence (const_rtx mem, en
>
>  /* Returns nonzero if a write to X might alias a previous read from
>     (or, if WRITEP is true, a write to) MEM.
> -   If MEM_CANONCALIZED is nonzero, CANON_MEM_ADDR is the canonicalized
> -   address of MEM, and MEM_MODE the mode for that access.  */
> +   If X_CANONCALIZED is true, then X_ADDR is the canonicalized address of
> X,
> +   and X_MODE the mode for that access.
> +   If MEM_CANONICALIZED is true, MEM is canonicalized.  */
>
>  static int
> -write_dependence_p (const_rtx mem, enum machine_mode mem_mode,
> -                   rtx canon_mem_addr, const_rtx x,
> -                   bool mem_canonicalized, bool writep)
> +write_dependence_p (const_rtx mem,
> +                   const_rtx x, enum machine_mode x_mode, rtx x_addr,
> +                   bool mem_canonicalized, bool x_canonicalized, bool
> writep)
>  {
> -  rtx x_addr, mem_addr;
> +  rtx mem_addr;
>    rtx base;
>    int ret;
>
> -  gcc_checking_assert (mem_canonicalized ? (canon_mem_addr != NULL_RTX)
> -                      : (canon_mem_addr == NULL_RTX && mem_mode ==
> VOIDmode));
> +  gcc_checking_assert (x_canonicalized
> +                      ? (x_addr != NULL_RTX && x_mode != VOIDmode)
> +                      : (x_addr == NULL_RTX && x_mode == VOIDmode));
>
>    if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem))
>      return 1;
> @@ -2593,17 +2596,21 @@ write_dependence_p (const_rtx mem, enum
>    if (MEM_ADDR_SPACE (mem) != MEM_ADDR_SPACE (x))
>      return 1;
>
> -  x_addr = XEXP (x, 0);
>    mem_addr = XEXP (mem, 0);
> -  if (!((GET_CODE (x_addr) == VALUE
> -        && GET_CODE (mem_addr) != VALUE
> -        && reg_mentioned_p (x_addr, mem_addr))
> -       || (GET_CODE (x_addr) != VALUE
> -           && GET_CODE (mem_addr) == VALUE
> -           && reg_mentioned_p (mem_addr, x_addr))))
> +  if (!x_addr)
>      {
> -      x_addr = get_addr (x_addr);
> -      mem_addr = get_addr (mem_addr);
> +      x_addr = XEXP (x, 0);
> +      if (!((GET_CODE (x_addr) == VALUE
> +            && GET_CODE (mem_addr) != VALUE
> +            && reg_mentioned_p (x_addr, mem_addr))
> +           || (GET_CODE (x_addr) != VALUE
> +               && GET_CODE (mem_addr) == VALUE
> +               && reg_mentioned_p (mem_addr, x_addr))))
> +       {
> +         x_addr = get_addr (x_addr);
> +         if (!mem_canonicalized)
> +           mem_addr = get_addr (mem_addr);
> +       }
>      }
>
>    base = find_base_term (mem_addr);
> @@ -2619,17 +2626,16 @@ write_dependence_p (const_rtx mem, enum
>                           GET_MODE (mem)))
>      return 0;
>
> -  x_addr = canon_rtx (x_addr);
> -  if (mem_canonicalized)
> -    mem_addr = canon_mem_addr;
> -  else
> +  if (!x_canonicalized)
>      {
> -      mem_addr = canon_rtx (mem_addr);
> -      mem_mode = GET_MODE (mem);
> +      x_addr = canon_rtx (x_addr);
> +      x_mode = GET_MODE (x);
>      }
> +  if (!mem_canonicalized)
> +    mem_addr = canon_rtx (mem_addr);
>
> -  if ((ret = memrefs_conflict_p (GET_MODE_SIZE (mem_mode), mem_addr,
> -                                SIZE_FOR_MODE (x), x_addr, 0)) != -1)
> +  if ((ret = memrefs_conflict_p (SIZE_FOR_MODE (mem), mem_addr,
> +                                GET_MODE_SIZE (x_mode), x_addr, 0)) != -1)
>      return ret;
>
>    if (nonoverlapping_memrefs_p (x, mem, false))
> @@ -2643,20 +2649,23 @@ write_dependence_p (const_rtx mem, enum
>  int
>  anti_dependence (const_rtx mem, const_rtx x)
>  {
> -  return write_dependence_p (mem, VOIDmode, NULL_RTX, x,
> -                            /*mem_canonicalized=*/false, /*writep=*/false);
> +  return write_dependence_p (mem, x, VOIDmode, NULL_RTX,
> +                            /*mem_canonicalized=*/false,
> +                            /*x_canonicalized*/false, /*writep=*/false);
>  }
>
> -/* Likewise, but we already have a canonicalized MEM_ADDR for MEM.
> -   Also, consider MEM in MEM_MODE (which might be from an enclosing
> -   STRICT_LOW_PART / ZERO_EXTRACT).  */
> +/* Likewise, but we already have a canonicalized MEM, and X_ADDR for X.
> +   Also, consider X in X_MODE (which might be from an enclosing
> +   STRICT_LOW_PART / ZERO_EXTRACT).
> +   If MEM_CANONICALIZED is true, MEM is canonicalized.  */
>
>  int
> -canon_anti_dependence (const_rtx mem, enum machine_mode mem_mode,
> -                      rtx mem_addr, const_rtx x)
> +canon_anti_dependence (const_rtx mem, bool mem_canonicalized,
> +                      const_rtx x, enum machine_mode x_mode, rtx x_addr)
>  {
> -  return write_dependence_p (mem, mem_mode, mem_addr, x,
> -                            /*mem_canonicalized=*/true, /*writep=*/false);
> +  return write_dependence_p (mem, x, x_mode, x_addr,
> +                            mem_canonicalized, /*x_canonicalized=*/true,
> +                            /*writep=*/false);
>  }
>
>  /* Output dependence: X is written after store in MEM takes place.  */
> @@ -2664,8 +2673,9 @@ canon_anti_dependence (const_rtx mem, en
>  int
>  output_dependence (const_rtx mem, const_rtx x)
>  {
> -  return write_dependence_p (mem, VOIDmode, NULL_RTX, x,
> -                            /*mem_canonicalized=*/false, /*writep=*/true);
> +  return write_dependence_p (mem, x, VOIDmode, NULL_RTX,
> +                            /*mem_canonicalized=*/false,
> +                            /*x_canonicalized*/false, /*writep=*/true);
>  }
>
>
> Index: cse.c
> ===================================================================
> --- cse.c       (revision 200133)
> +++ cse.c       (working copy)
> @@ -1837,7 +1837,7 @@ check_dependence (rtx *x, void *data)
>  {
>    struct check_dependence_data *d = (struct check_dependence_data *) data;
>    if (*x && MEM_P (*x))
> -    return canon_anti_dependence (d->exp, d->mode, d->addr, *x);
> +    return canon_anti_dependence (*x, true, d->exp, d->mode, d->addr);
>    else
>      return 0;
>  }
> Index: cselib.c
> ===================================================================
> --- cselib.c    (revision 200133)
> +++ cselib.c    (working copy)
> @@ -2263,8 +2263,8 @@ cselib_invalidate_mem (rtx mem_rtx)
>               continue;
>             }
>           if (num_mems < PARAM_VALUE (PARAM_MAX_CSELIB_MEMORY_LOCATIONS)
> -             && ! canon_anti_dependence (mem_rtx, GET_MODE (mem_rtx),
> -                                         mem_addr, x))
> +             && ! canon_anti_dependence (x, false, mem_rtx,
> +                                         GET_MODE (mem_rtx), mem_addr))
>             {
>               has_mem = true;
>               num_mems++;
> Index: rtl.h
> ===================================================================
> --- rtl.h       (revision 200133)
> +++ rtl.h       (working copy)
> @@ -2705,8 +2705,8 @@ extern int canon_true_dependence (const_
>                                   const_rtx, rtx);
>  extern int read_dependence (const_rtx, const_rtx);
>  extern int anti_dependence (const_rtx, const_rtx);
> -extern int canon_anti_dependence (const_rtx, enum machine_mode, rtx,
> -                                 const_rtx);
> +extern int canon_anti_dependence (const_rtx, bool,
> +                                 const_rtx, enum machine_mode, rtx);
>  extern int output_dependence (const_rtx, const_rtx);
>  extern int may_alias_p (const_rtx, const_rtx);
>  extern void init_alias_target (void);
>