combine.c (combinable_i3pat): Don't forbid occurrences of i2dest or i1dest in inner_d...

* combine.c (combinable_i3pat): Don't forbid occurrences of
i2dest or i1dest in inner_dest if inner_dest is a mem.

From-SVN: r69566

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 5aeacafee43d7f85139c3f06f2e96ce638375c14..644da7bf32381311ce627162670222a0a4e23f81 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+Fri Jul 18 15:22:28 2003  Alexandre Oliva  <aoliva@redhat.com>
+
+       * combine.c (combinable_i3pat): Don't forbid occurrences of
+       i2dest or i1dest in inner_dest if inner_dest is a mem.
+
 Fri Jul 18 17:05:57 CEST 2003  Jan Hubicka  <jh@suse.cz>
 
        * cgraph.c (cgraph_remove_node): Clear the hash table slot.

diff --git a/gcc/combine.c b/gcc/combine.c
index 5a752014873fe3b4be7d7faedba37427b82d481c..883f504a50b882d63a3d0caf4b02b195f9b4a3ce 100644 (file)
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -1301,9 +1301,14 @@ combinable_i3pat (rtx i3, rtx *loc, rtx i2dest, rtx i1dest,
             || GET_CODE (inner_dest) == ZERO_EXTRACT)
        inner_dest = XEXP (inner_dest, 0);
 
-      /* Check for the case where I3 modifies its output, as
-        discussed above.  */
-      if ((inner_dest != dest
+      /* Check for the case where I3 modifies its output, as discussed
+        above.  We don't want to prevent pseudos from being combined
+        into the address of a MEM, so only prevent the combination if
+        i1 or i2 set the same MEM.  */
+      if ((inner_dest != dest &&
+          (GET_CODE (inner_dest) != MEM
+           || rtx_equal_p (i2dest, inner_dest)
+           || (i1dest && rtx_equal_p (i1dest, inner_dest)))
           && (reg_overlap_mentioned_p (i2dest, inner_dest)
               || (i1dest && reg_overlap_mentioned_p (i1dest, inner_dest))))