(expand_field_assignment): Take SUBREG_WORD into account when have STRICT_LOW_PART.

(expand_field_assignment): Take SUBREG_WORD into account when have
STRICT_LOW_PART.
(make_extraction): Make a STRICT_LOW_PART at any low-order word.

From-SVN: r11775

diff --git a/gcc/combine.c b/gcc/combine.c
index 4d0ac4c..cf5ba4a 100644 (file)
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -4957,7 +4957,7 @@ expand_field_assignment (x)
        {
          inner = SUBREG_REG (XEXP (SET_DEST (x), 0));
          len = GET_MODE_BITSIZE (GET_MODE (XEXP (SET_DEST (x), 0)));
-         pos = const0_rtx;
+         pos = GEN_INT (BITS_PER_WORD * SUBREG_WORD (XEXP (SET_DEST (x), 0)));
        }
       else if (GET_CODE (SET_DEST (x)) == ZERO_EXTRACT
               && GET_CODE (XEXP (SET_DEST (x), 1)) == CONST_INT)
@@ -5133,7 +5133,8 @@ make_extraction (mode, inner, pos, pos_rtx, len,
 
   if (tmode != BLKmode
       && ! (spans_byte && inner_mode != tmode)
-      && ((pos_rtx == 0 && pos == 0 && GET_CODE (inner) != MEM
+      && ((pos_rtx == 0 && (pos % BITS_PER_WORD) == 0
+          && GET_CODE (inner) != MEM
           && (! in_dest
               || (GET_CODE (inner) == REG
                   && (movstrict_optab->handlers[(int) tmode].insn_code
@@ -5153,8 +5154,8 @@ make_extraction (mode, inner, pos, pos_rtx, len,
         field.  If the original and current mode are the same, we need not
         adjust the offset.  Otherwise, we do if bytes big endian.  
 
-        If INNER is not a MEM, get a piece consisting of the just the field
-        of interest (in this case POS must be 0).  */
+        If INNER is not a MEM, get a piece consisting of just the field
+        of interest (in this case POS % BITS_PER_WORD must be 0).  */
 
       if (GET_CODE (inner) == MEM)
        {
@@ -5178,10 +5179,11 @@ make_extraction (mode, inner, pos, pos_rtx, len,
            new = gen_rtx (SUBREG, tmode, inner,
                           (WORDS_BIG_ENDIAN
                            && GET_MODE_SIZE (inner_mode) > UNITS_PER_WORD
-                           ? ((GET_MODE_SIZE (inner_mode)
-                               - GET_MODE_SIZE (tmode))
-                              / UNITS_PER_WORD)
-                           : 0));
+                           ? (((GET_MODE_SIZE (inner_mode)
+                                - GET_MODE_SIZE (tmode))
+                               / UNITS_PER_WORD)
+                              - pos / BITS_PER_WORD)
+                           : pos / BITS_PER_WORD));
          else
            new = inner;
        }