cselib.c (max_value_regs): New.

2002-05-20  David S. Miller  <davem@redhat.com>

	* cselib.c (max_value_regs): New.
	(cselib_lookup, cselib_invalidate_regno): Initialize it when
	adding new entries to the REG_VALUES table and we are dealing with
	a hard register.
	(clear_table): Initialize it.
	(cselib_invalidate_regno): Use it to determine which hard
	registers to scan when mode is not VOIDmode.

From-SVN: r53821

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 62dc3234fdf7ae76db931a99adec431a9e8eed6a..662d761b1a56182883bcb71e9d05fb5f00f6b479 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,13 @@
+2002-05-20  David S. Miller  <davem@redhat.com>
+
+       * cselib.c (max_value_regs): New.
+       (cselib_lookup, cselib_invalidate_regno): Initialize it when
+       adding new entries to the REG_VALUES table and we are dealing with
+       a hard register.
+       (clear_table): Initialize it.
+       (cselib_invalidate_regno): Use it to determine which hard
+       registers to scan when mode is not VOIDmode.
+
 2002-05-24  Alan Modra  <amodra@bigpond.net.au>
 
        * config/rs6000/rs6000.c (output_toc): Mask longs to 32 bits.

diff --git a/gcc/cselib.c b/gcc/cselib.c
index 0eb17b8a836224803ce6e919ac955cc28cd0afe8..b0348fbc46209b4dc6f3b6d4f3b88313545d3bb5 100644 (file)
--- a/gcc/cselib.c
+++ b/gcc/cselib.c
@@ -104,6 +104,10 @@ static int n_useless_values;
 static varray_type reg_values;
 #define REG_VALUES(I) VARRAY_ELT_LIST (reg_values, (I))
 
+/* The largest number of hard regs used by any entry added to the
+   REG_VALUES table.  Cleared on each clear_table() invocation.   */
+static unsigned int max_value_regs;
+
 /* Here the set of indices I with REG_VALUES(I) != 0 is saved.  This is used
    in clear_table() for fast emptying.  */
 static varray_type used_regs;
@@ -227,6 +231,8 @@ clear_table (clear_all)
     for (i = 0; i < VARRAY_ACTIVE_SIZE (used_regs); i++)
       REG_VALUES (VARRAY_UINT (used_regs, i)) = 0;
 
+  max_value_regs = 0;
+
   VARRAY_POP_ALL (used_regs);
 
   htab_empty (hash_table);
@@ -897,6 +903,14 @@ cselib_lookup (x, mode, create)
       if (! create)
        return 0;
 
+      if (i < FIRST_PSEUDO_REGISTER)
+       {
+         unsigned int n = HARD_REGNO_NREGS (i, mode);
+
+         if (n > max_value_regs)
+           max_value_regs = n;
+       }
+
       e = new_cselib_val (++next_unknown_value, GET_MODE (x));
       e->locs = new_elt_loc_list (e->locs, x);
       if (REG_VALUES (i) == 0)
@@ -957,11 +971,22 @@ cselib_invalidate_regno (regno, mode)
      pseudos, only REGNO is affected.  For hard regs, we must take MODE
      into account, and we must also invalidate lower register numbers
      if they contain values that overlap REGNO.  */
-  endregno = regno + 1;
   if (regno < FIRST_PSEUDO_REGISTER && mode != VOIDmode) 
-    endregno = regno + HARD_REGNO_NREGS (regno, mode);
+    {
+      if (regno < max_value_regs)
+       i = 0;
+      else
+       i = regno - max_value_regs;
 
-  for (i = 0; i < endregno; i++)
+      endregno = regno + HARD_REGNO_NREGS (regno, mode);
+    }
+  else
+    {
+      i = regno;
+      endregno = regno + 1;
+    }
+
+  for (; i < endregno; i++)
     {
       struct elt_list **l = &REG_VALUES (i);
 
@@ -1171,6 +1196,14 @@ cselib_record_set (dest, src_elt, dest_addr_elt)
       if (REG_VALUES (dreg) == 0)
         VARRAY_PUSH_UINT (used_regs, dreg);
 
+      if (dreg < FIRST_PSEUDO_REGISTER)
+       {
+         unsigned int n = HARD_REGNO_NREGS (dreg, GET_MODE (dest));
+
+         if (n > max_value_regs)
+           max_value_regs = n;
+       }
+
       REG_VALUES (dreg) = new_elt_list (REG_VALUES (dreg), src_elt);
       if (src_elt->locs == 0)
        n_useless_values--;