PR bootstrap/10983

	* combine.c (make_extraction): Use gen_lowpart_for_combine
	when extracting from a REG and not in the destination of a SET.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@67916 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c526f71..9a54246 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2003-06-13  Jim Wilson  <wilson@tuliptree.org>
+            Eric Botcazou  <ebotcazou@libertysurf.fr>
+
+       PR bootstrap/10983
+       * combine.c (make_extraction): Use gen_lowpart_for_combine
+       when extracting from a REG and not in the destination of a SET.
+
 2003-06-13  Doug Evans  <dje@sebabeach.org>
 
        * tsystem.h (abort): Declare in inhibit_libc case to remove build

diff --git a/gcc/combine.c b/gcc/combine.c
index 3e2f089..1638576 100644 (file)
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -6139,30 +6139,35 @@ make_extraction (enum machine_mode mode, rtx inner, HOST_WIDE_INT pos,
        }
       else if (GET_CODE (inner) == REG)
        {
-         /* We can't call gen_lowpart_for_combine here since we always want
-            a SUBREG and it would sometimes return a new hard register.  */
          if (tmode != inner_mode)
            {
-             HOST_WIDE_INT final_word = pos / BITS_PER_WORD;
-
-             if (WORDS_BIG_ENDIAN
-                 && GET_MODE_SIZE (inner_mode) > UNITS_PER_WORD)
-               final_word = ((GET_MODE_SIZE (inner_mode)
-                              - GET_MODE_SIZE (tmode))
-                             / UNITS_PER_WORD) - final_word;
-
-             final_word *= UNITS_PER_WORD;
-             if (BYTES_BIG_ENDIAN &&
-                 GET_MODE_SIZE (inner_mode) > GET_MODE_SIZE (tmode))
-               final_word += (GET_MODE_SIZE (inner_mode)
-                              - GET_MODE_SIZE (tmode)) % UNITS_PER_WORD;
-
-             /* Avoid creating invalid subregs, for example when
-                simplifying (x>>32)&255.  */
-             if (final_word >= GET_MODE_SIZE (inner_mode))
-               return NULL_RTX;
-
-             new = gen_rtx_SUBREG (tmode, inner, final_word);
+             if (in_dest)
+               {
+                 /* We can't call gen_lowpart_for_combine here since we always want
+                    a SUBREG and it would sometimes return a new hard register.  */
+                 HOST_WIDE_INT final_word = pos / BITS_PER_WORD;
+
+                 if (WORDS_BIG_ENDIAN
+                     && GET_MODE_SIZE (inner_mode) > UNITS_PER_WORD)
+                   final_word = ((GET_MODE_SIZE (inner_mode)
+                                  - GET_MODE_SIZE (tmode))
+                                 / UNITS_PER_WORD) - final_word;
+
+                 final_word *= UNITS_PER_WORD;
+                 if (BYTES_BIG_ENDIAN &&
+                     GET_MODE_SIZE (inner_mode) > GET_MODE_SIZE (tmode))
+                   final_word += (GET_MODE_SIZE (inner_mode)
+                                  - GET_MODE_SIZE (tmode)) % UNITS_PER_WORD;
+
+                 /* Avoid creating invalid subregs, for example when
+                    simplifying (x>>32)&255.  */
+                 if (final_word >= GET_MODE_SIZE (inner_mode))
+                   return NULL_RTX;
+
+                 new = gen_rtx_SUBREG (tmode, inner, final_word);
+               }
+             else
+               new = gen_lowpart_for_combine (tmode, inner);
            }
          else
            new = inner;