From: Richard Henderson <rth@cygnus.com>
Date: Sat, 16 Oct 1999 07:08:27 +0000 (-0700)
Subject: gcse.c (hash_expr_1): Add in MEM_ALIAS_SET.
X-Git-Tag: prereleases/libstdc++-2.92~10000
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=297c3335895f3eba396572abb4e760633511f1a4;p=thirdparty%2Fgcc.git

gcse.c (hash_expr_1): Add in MEM_ALIAS_SET.

        * gcse.c (hash_expr_1): Add in MEM_ALIAS_SET.
        (expr_equiv_p): Reject memories with different alias sets.

From-SVN: r30039
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index b6e34ecf649d..fdae41bc012d 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+Sat Oct 16 00:07:01 1999  Richard Henderson  <rth@cygnus.com>
+
+	* gcse.c (hash_expr_1): Add in MEM_ALIAS_SET.
+	(expr_equiv_p): Reject memories with different alias sets.
+
 Fri Oct 15 15:17:29 1999  Greg McGary  <gkm@gnu.org>
 
 	* flags.h (flag_bounds_check, flag_bounded_pointers): New extern decls.
diff --git a/gcc/gcse.c b/gcc/gcse.c
index d660a493dc14..f43f3823c42f 100644
--- a/gcc/gcse.c
+++ b/gcc/gcse.c
@@ -1446,6 +1446,7 @@ hash_expr_1 (x, mode, do_not_record_p)
 	  return 0;
 	}
       hash += (unsigned) MEM;
+      hash += MEM_ALIAS_SET (x);
       x = XEXP (x, 0);
       goto repeat;
 
@@ -1578,6 +1579,14 @@ expr_equiv_p (x, y)
     case REG:
       return REGNO (x) == REGNO (y);
 
+    case MEM:
+      /* Can't merge two expressions in different alias sets, since we can
+	 decide that the expression is transparent in a block when it isn't,
+	 due to it being set with the different alias set.  */
+      if (MEM_ALIAS_SET (x) != MEM_ALIAS_SET (y))
+	return 0;
+      break;
+
     /*  For commutative operations, check both orders.  */
     case PLUS:
     case MULT: