function.c (purge_addressof_1): If the note accesses a mem+addressof in a wider mode...

        * function.c (purge_addressof_1): If the note accesses a mem+addressof
        in a wider mode than any replacement, adjust the cached replacement.
        Cache trivial substitutions as well.

From-SVN: r24629

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index e94632380762312dc3cce6a69da5111b26b77b83..9eb38ff4081c95fa76242e43b55ba7b83dee6f17 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+Tue Jan 12 00:23:31 1999  Richard Henderson  <rth@cygnus.com>
+
+       * function.c (purge_addressof_1): If the note accesses a mem+addressof
+       in a wider mode than any replacement, adjust the cached replacement.
+       Cache trivial substitutions as well.
+
 Tue Jan 12 00:06:00 1999  Richard Henderson  <rth@cygnus.com>
 
         * Makefile.in (OBJECTS): Add sbitmap.o.

diff --git a/gcc/function.c b/gcc/function.c
index c152193e9bb5db9c1032952b93e158e5b0ebf7ab..87a923b18fa7c923eb05940d2a5dbd2b2fd9294f 100644 (file)
--- a/gcc/function.c
+++ b/gcc/function.c
@@ -2899,11 +2899,36 @@ purge_addressof_1 (loc, insn, force, store)
 
              for (tem = purge_addressof_replacements; tem != NULL_RTX;
                   tem = XEXP (XEXP (tem, 1), 1))
-               if (rtx_equal_p (x, XEXP (tem, 0)))
-                 {
-                   *loc = XEXP (XEXP (tem, 1), 0);
-                   return;
-                 }
+               {
+                 rtx y = XEXP (tem, 0);
+                 if (GET_CODE (y) == MEM
+                     && rtx_equal_p (XEXP (x, 0), XEXP (y, 0)))
+                   {
+                     /* It can happen that the note may speak of things in
+                        a wider (or just different) mode than the code did. 
+                        This is especially true of REG_RETVAL.  */
+
+                     rtx z = XEXP (XEXP (tem, 1), 0);
+                     if (GET_MODE (x) != GET_MODE (y))
+                       {
+                         if (GET_CODE (z) == SUBREG && SUBREG_WORD (z) == 0)
+                           z = SUBREG_REG (z);
+
+                         /* ??? If we'd gotten into any of the really complex
+                            cases below, I'm not sure we can do a proper
+                            replacement.  Might we be able to delete the
+                            note in some cases?  */
+                         if (GET_MODE_SIZE (GET_MODE (x))
+                             < GET_MODE_SIZE (GET_MODE (y)))
+                           abort ();
+
+                         z = gen_lowpart (GET_MODE (x), z);
+                       }
+
+                     *loc = z;
+                     return;
+                   }
+               }
 
              /* There should always be such a replacement.  */
              abort ();
@@ -2991,7 +3016,15 @@ purge_addressof_1 (loc, insn, force, store)
            }
        }
       else if (validate_change (insn, loc, sub, 0))
-       goto restart;
+       {
+         /* Remember the replacement so that the same one can be done
+            on the REG_NOTES.  */
+         purge_addressof_replacements
+           = gen_rtx_EXPR_LIST (VOIDmode, x,
+                                gen_rtx_EXPR_LIST (VOIDmode, sub,
+                                                   purge_addressof_replacements));
+         goto restart;
+       }
     give_up:;
       /* else give up and put it into the stack */
     }