rtlanal.c (subreg_regno_offset): Return correct offset for big endian paradoxical subregs.

	* rtlanal.c (subreg_regno_offset): Return correct offset for
	big endian paradoxical subregs.

From-SVN: r55650

gcc/ChangeLog

-Mon Jul 22 15:21:41 2002  J"orn Rennecke <joern.rennecke@superh.com>
+Mon Jul 22 15:27:25 2002  J"orn Rennecke <joern.rennecke@superh.com>
+
+	* rtlanal.c (subreg_regno_offset): Return correct offset for
+	big endian paradoxical subregs.
 
 	* optabs.c (expand_vector_unop): Don't expand using sub_optab
 	if we got the wrong mode.

gcc/rtlanal.c

@@ -3117,6 +3117,16 @@ subreg_regno_offset (xregno, xmode, offset, ymode)
 
   nregs_xmode = HARD_REGNO_NREGS (xregno, xmode);
   nregs_ymode = HARD_REGNO_NREGS (xregno, ymode);
+
+  /* If this is a big endian paradoxical subreg, which uses more actual
+     hard registers than the original register, we must return a negative
+     offset so that we find the proper highpart of the register.  */
+  if (offset == 0
+      && nregs_ymode > nregs_xmode
+      && (GET_MODE_SIZE (ymode) > UNITS_PER_WORD
+	  ? WORDS_BIG_ENDIAN : BYTES_BIG_ENDIAN))
+    return nregs_xmode - nregs_ymode;
+
   if (offset == 0 || nregs_xmode == nregs_ymode)
     return 0;