Patchwork derive alias information from named address spaces.

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Submitter Bingfeng Mei
Date Sept. 22, 2011, 12:20 p.m.
Message ID <7FB04A5C213E9943A72EE127DB74F0ADD15FD2F4A6@SJEXCHCCR02.corp.ad.broadcom.com>
Download mbox | patch
Permalink /patch/115940/
State New
Headers show

Comments

Bingfeng Mei - Sept. 22, 2011, 12:20 p.m.
Hello,
Here is the updated patch. OK now? 

Thanks,
Bingfeng

2011-09-22  Bingfeng Mei <bmei@broadcom.com>

	* alias.c (mems_in_disjoint_address_spaces_p) New function.
	(nonoverlapping_memrefs_p): Use mems_in_disjoint_address_sapces_p
	to derive alias information.
	(nonoverlapping_memrefs_p): ditto. (write_dependence_p): ditto.
	(write_dependence_p): ditto.
        

> -----Original Message-----
> From: Richard Henderson [mailto:rth@redhat.com]
> Sent: 20 September 2011 17:15
> To: Bingfeng Mei
> Cc: gcc-patches@gcc.gnu.org; Ulrich Weigand
> Subject: Re: [PATCH] derive alias information from named address spaces.
> 
> On 09/20/2011 01:46 AM, Bingfeng Mei wrote:
> >    if (MEM_P (rtlx) && MEM_P (rtly)
> >        && MEM_ADDR_SPACE (rtlx) != MEM_ADDR_SPACE (rtly))
> > -    return 0;
> > +    {
> > +      if (!targetm.addr_space.subset_p (MEM_ADDR_SPACE (rtlx),
> > +                                        MEM_ADDR_SPACE (rtly))
> > +         && !targetm.addr_space.subset_p (MEM_ADDR_SPACE (rtly),
> > +                                          MEM_ADDR_SPACE (rtlx)))
> > +        return 1;
> > +      else
> > +        return 0;
> > +    }
> 
> You have 4 copies of this.  Please pull it out into
> a new predicate function.
> 
> 
> r~

Patch

Index: alias.c
===================================================================
--- alias.c	(revision 178972)
+++ alias.c	(working copy)
@@ -155,6 +155,7 @@  static int base_alias_check (rtx, rtx, e
 			     enum machine_mode);
 static rtx find_base_value (rtx);
 static int mems_in_disjoint_alias_sets_p (const_rtx, const_rtx);
+static int mems_in_disjoint_address_spaces_p (const_rtx, const_rtx);
 static int insert_subset_children (splay_tree_node, void*);
 static alias_set_entry get_alias_set_entry (alias_set_type);
 static const_rtx fixed_scalar_and_varying_struct_p (const_rtx, const_rtx, rtx, rtx,
@@ -400,6 +401,17 @@  mems_in_disjoint_alias_sets_p (const_rtx
   return ! alias_sets_conflict_p (MEM_ALIAS_SET (mem1), MEM_ALIAS_SET (mem2));
 }
 
+/* Return nonzero if the address spaces for MEM1 and MEM2 are disjoint */
+static inline int
+mems_in_disjoint_address_spaces_p (const_rtx mem1, const_rtx mem2)
+{
+  
+  return (!targetm.addr_space.subset_p (MEM_ADDR_SPACE (mem1),
+                                        MEM_ADDR_SPACE (mem2))
+         && !targetm.addr_space.subset_p (MEM_ADDR_SPACE (mem2),
+                                          MEM_ADDR_SPACE (mem1)));
+}
+
 /* Insert the NODE into the splay tree given by DATA.  Used by
    record_alias_subset via splay_tree_foreach.  */
 
@@ -2306,11 +2318,11 @@  nonoverlapping_memrefs_p (const_rtx x, c
     return 1;
 
   /* If we have MEMs refering to different address spaces (which can
-     potentially overlap), we cannot easily tell from the addresses
-     whether the references overlap.  */
+     potentially overlap), they are not aliased if neither is subset
+     of the other one. */
   if (MEM_P (rtlx) && MEM_P (rtly)
       && MEM_ADDR_SPACE (rtlx) != MEM_ADDR_SPACE (rtly))
-    return 0;
+    return  mems_in_disjoint_address_spaces_p (rtlx, rtly);
 
   /* Get the base and offsets of both decls.  If either is a register, we
      know both are and are the same, so use that as the base.  The only
@@ -2417,10 +2429,10 @@  true_dependence_1 (const_rtx mem, enum m
     return 0;
 
   /* If we have MEMs refering to different address spaces (which can
-     potentially overlap), we cannot easily tell from the addresses
-     whether the references overlap.  */
+     potentially overlap), they are not aliased if neither is subset
+     of the other one. */
   if (MEM_ADDR_SPACE (mem) != MEM_ADDR_SPACE (x))
-    return 1;
+    return  (!mems_in_disjoint_address_spaces_p (mem, x));
 
   if (! mem_addr)
     {
@@ -2542,10 +2554,10 @@  write_dependence_p (const_rtx mem, const
     return 0;
 
   /* If we have MEMs refering to different address spaces (which can
-     potentially overlap), we cannot easily tell from the addresses
-     whether the references overlap.  */
+     potentially overlap), they are not aliased if neither is subset
+     of the other one. */
   if (MEM_ADDR_SPACE (mem) != MEM_ADDR_SPACE (x))
-    return 1;
+    return  (!mems_in_disjoint_address_spaces_p (mem, x));
 
   x_addr = XEXP (x, 0);
   mem_addr = XEXP (mem, 0);
@@ -2637,10 +2649,10 @@  may_alias_p (const_rtx mem, const_rtx x)
     return 0;
 
   /* If we have MEMs refering to different address spaces (which can
-     potentially overlap), we cannot easily tell from the addresses
-     whether the references overlap.  */
+     potentially overlap), they are not aliased if neither is subset
+     of the other one. */
   if (MEM_ADDR_SPACE (mem) != MEM_ADDR_SPACE (x))
-    return 1;
+    return  (!mems_in_disjoint_address_spaces_p (mem, x));
 
   x_addr = XEXP (x, 0);
   mem_addr = XEXP (mem, 0);