alias.c (find_base_value): When copying arguments, return the tenative value for...

        * alias.c (find_base_value): When copying arguments, return the
        tenative value for a hard register.

From-SVN: r16319

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 881ffd02b1efd10a6d13566a889d2e259677ea7e..f1ed0dd6948210d46199fda20e16eb84c89c2cc5 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+Tue Nov  4 16:07:15 1997  Jeffrey A Law  (law@cygnus.com)
+
+       * alias.c (find_base_value): When copying arguments, return the
+       tenative value for a hard register.
+
 Tue Nov  4 13:40:35 1997  Doug Evans  <devans@canuck.cygnus.com>
 
        * c-lex.c (MULTIBYTE_CHARS): #undef if cross compiling.

diff --git a/gcc/alias.c b/gcc/alias.c
index 855abaeec20460b5e93afabecf32bc5b4bb7192e..0943444185a2c3b00cbc93fa4d486dc38879af40 100644 (file)
--- a/gcc/alias.c
+++ b/gcc/alias.c
@@ -95,16 +95,19 @@ find_base_value (src)
       return src;
 
     case REG:
-      /* If this REG is related to a known base value, return it.  */
-      if (reg_base_value[REGNO (src)])
-       return reg_base_value[REGNO (src)];
-
       /* At the start of a function argument registers have known base
         values which may be lost later.  Returning an ADDRESS
         expression here allows optimization based on argument values
         even when the argument registers are used for other purposes.  */
       if (REGNO (src) < FIRST_PSEUDO_REGISTER && copying_arguments)
        return new_reg_base_value[REGNO (src)];
+
+      /* If this REG is related to a known base value, return it.
+        This must happen after the arg register check above to avoid
+        circular set chains.  */
+      if (reg_base_value[REGNO (src)])
+       return reg_base_value[REGNO (src)];
+
       return src;
 
     case MEM: