loop.c (strength_reduce): Show when new register made for giv is known to be a pointe...

	* loop.c (strength_reduce): Show when new register made for
	giv is known to be a pointer and its aligment if so and known.
	(loop_dump_aux): Show VERBOSE parameter unused.

From-SVN: r36975

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 21c3fd8..5cacc9f 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,9 @@
 Fri Oct 20 13:33:16 2000  Richard Kenner  <kenner@vlsi1.ultra.nyu.edu>
 
+       * loop.c (strength_reduce): Show when new register made for
+       giv is known to be a pointer and its aligment if so and known.
+       (loop_dump_aux): Show VERBOSE parameter unused.
+
        * gcse.c (set_hash_table_size): Now unsigned.
        * sdbout.c (template_name_p): Add "const" to avoid warnings.
        (sdbout_record_type_name, plain_type_1, sdbout_symbol): Likewise.

diff --git a/gcc/loop.c b/gcc/loop.c
index 23ee292..604b791 100644 (file)
--- a/gcc/loop.c
+++ b/gcc/loop.c
@@ -4173,6 +4173,45 @@ strength_reduce (loop, insn_count, flags)
            v->new_reg = replace_rtx (v->new_reg,
                                      v->same->dest_reg, v->same->new_reg);
 
+         /* See if this register is known to be a pointer to something.  If
+            so, see if we can find the alignment.  First see if there is a
+            destination register that is a pointer.  If so, this shares the
+            alignment too.  Next see if we can deduce anything from the
+            computational information.  If not, and this is a DEST_ADDR
+            giv, at least we know that it's a pointer, though we don't know
+            the alignment.  */
+         if (GET_CODE (v->new_reg) == REG
+             && v->giv_type == DEST_REG
+             && REGNO_POINTER_FLAG (REGNO (v->dest_reg)))
+           mark_reg_pointer (v->new_reg,
+                             REGNO_POINTER_ALIGN (REGNO (v->dest_reg)));
+         else if (GET_CODE (v->new_reg) == REG
+                  && REGNO_POINTER_FLAG (REGNO (v->src_reg)))
+           {
+             unsigned int align = REGNO_POINTER_ALIGN (REGNO (v->src_reg));
+
+             if (align == 0
+                 || GET_CODE (v->add_val) != CONST_INT
+                 || INTVAL (v->add_val) % (align / BITS_PER_UNIT) != 0)
+               align = 0;
+
+             mark_reg_pointer (v->new_reg, align);
+           }
+         else if (GET_CODE (v->new_reg) == REG
+                  && GET_CODE (v->add_val) == REG
+                  && REGNO_POINTER_FLAG (REGNO (v->add_val)))
+           {
+             unsigned int align = REGNO_POINTER_ALIGN (REGNO (v->add_val));
+
+             if (align == 0
+                 || INTVAL (v->mult_val) % (align / BITS_PER_UNIT) != 0)
+               align = 0;
+
+             mark_reg_pointer (v->new_reg, align);
+           }
+         else if (GET_CODE (v->new_reg) == REG && v->giv_type == DEST_ADDR)
+           mark_reg_pointer (v->new_reg, 0);
+
          if (v->giv_type == DEST_ADDR)
            /* Store reduced reg as the address in the memref where we found
               this giv.  */
@@ -9302,7 +9341,7 @@ static void
 loop_dump_aux (loop, file, verbose)
      const struct loop *loop;
      FILE *file;
-     int verbose;
+     int verbose ATTRIBUTE_UNUSED;
 {
   rtx label;