diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ef26693da65..2a7ba98e8ca 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2004-05-03  Joe Buck <jbuck@welsh-buck.org>
+
+	* cppfiles.c (pchf_adder): Eliminate use of |= in d->have_once_only
+	assignment.
+
 2004-05-03  Eric Christopher  <echristo@redhat.com>
 
 	* config/mips/mips.md: Fix branch length attribute definition.
diff --git a/gcc/cppfiles.c b/gcc/cppfiles.c
index 41657ce91ff..fab78fa2c25 100644
--- a/gcc/cppfiles.c
+++ b/gcc/cppfiles.c
@@ -1398,7 +1398,8 @@ pchf_adder (void **slot, void *data)
 	return 1;
 
       d->entries[count].once_only = f->once_only;
-      d->have_once_only |= f->once_only;
+      /* |= is avoided in the next line because of an HP C compiler bug */
+      d->have_once_only = d->have_once_only | f->once_only; 
       if (f->buffer_valid)
 	  md5_buffer ((const char *)f->buffer,
 		      f->st.st_size, d->entries[count].sum);