diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 5be4fa09d18..e999c3871b8 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,7 @@
+Mon Sep  1 16:25:34 1997  Jim Wilson  <wilson@cygnus.com>
+
+	* cse.c (cse_insn): Don't record BLKmode values.
+
 Mon Sep  1 11:25:47 1997  Stephen Williams  (steve@icarus.icarus.com)
 
 	* i960.h (LINK_SPEC): Handle "-mjX" and "-mrp" switches.
diff --git a/gcc/cse.c b/gcc/cse.c
index 096a630aeb4..71bc3584432 100644
--- a/gcc/cse.c
+++ b/gcc/cse.c
@@ -7297,6 +7297,10 @@ cse_insn (insn, in_libcall_block)
 	if ((flag_float_store
 	     && GET_CODE (dest) == MEM
 	     && FLOAT_MODE_P (GET_MODE (dest)))
+	    /* Don't record BLKmode values, because we don't know the
+	       size of it, and can't be sure that other BLKmode values
+	       have the same or smaller size.  */
+	    || GET_MODE (dest) == BLKmode
 	    /* Don't record values of destinations set inside a libcall block
 	       since we might delete the libcall.  Things should have been set
 	       up so we won't want to reuse such a value, but we play it safe