emit-rtl.c (gen_highpart): The high part of a CONST_INT is not zero if...

	* emit-rtl.c (gen_highpart): The high part of a CONST_INT is not zero
	if HOST_BITS_PER_WIDE_INT is larger than BITS_PER_WORD.
	* final.c (split_double): Sign extend both halves of a split CONST_INT.

From-SVN: r19375

gcc/ChangeLog

+Wed Apr 22 15:52:22 1998  John Carr  <jfc@mit.edu>
+
+	* emit-rtl.c (gen_highpart): The high part of a CONST_INT is not zero
+	if HOST_BITS_PER_WIDE_INT is larger than BITS_PER_WORD.
+
+	* final.c (split_double): Sign extend both halves of a split CONST_INT.
+
 Wed Apr 22 10:42:45 1998  Jeffrey A Law  (law@cygnus.com)
 
 	* mips.c (compute_frame_size): Change only argument to a HOST_WIDE_INT.

gcc/emit-rtl.c

@@ -720,14 +720,13 @@ gen_lowpart_common (mode, x)
 		: GEN_INT (CONST_DOUBLE_LOW (x)));
       else
 	{
-	  /* MODE must be narrower than HOST_BITS_PER_INT.  */
+	  /* MODE must be narrower than HOST_BITS_PER_WIDE_INT.  */
 	  int width = GET_MODE_BITSIZE (mode);
 	  HOST_WIDE_INT val = (GET_CODE (x) == CONST_INT ? INTVAL (x)
 			       : CONST_DOUBLE_LOW (x));
 
-	  if (((val & ((HOST_WIDE_INT) (-1) << (width - 1)))
-	       != ((HOST_WIDE_INT) (-1) << (width - 1))))
-	    val &= ((HOST_WIDE_INT) 1 << width) - 1;
+	  /* Sign extend to HOST_WIDE_INT.  */
+	  val = val << (HOST_BITS_PER_WIDE_INT - width) >> (HOST_BITS_PER_WIDE_INT - width);
 
 	  return (GET_CODE (x) == CONST_INT && INTVAL (x) == val ? x
 		  : GEN_INT (val));
@@ -984,7 +983,11 @@ gen_highpart (mode, x)
       )
     return GEN_INT (CONST_DOUBLE_HIGH (x) & GET_MODE_MASK (mode));
   else if (GET_CODE (x) == CONST_INT)
-    return const0_rtx;
+    {
+      if (HOST_BITS_PER_WIDE_INT <= BITS_PER_WORD)
+	return const0_rtx;
+      return GEN_INT (INTVAL (x) >> (HOST_BITS_PER_WIDE_INT - BITS_PER_WORD));
+    }
   else if (GET_CODE (x) == MEM)
     {
       register int offset = 0;

gcc/final.c

@@ -3677,16 +3677,12 @@ split_double (value, first, second)
       if (HOST_BITS_PER_WIDE_INT >= (2 * BITS_PER_WORD))
 	{
 	  /* In this case the CONST_INT holds both target words.
-	     Extract the bits from it into two word-sized pieces.  */
+	     Extract the bits from it into two word-sized pieces.
+	     Sign extend each half to HOST_WIDE_INT.  */
 	  rtx low, high;
-	  HOST_WIDE_INT word_mask;
-	  /* Avoid warnings for shift count >= BITS_PER_WORD.  */
-	  int shift_count = BITS_PER_WORD - 1;
-
-	  word_mask = (HOST_WIDE_INT) 1 << shift_count;
-	  word_mask |= word_mask - 1;
-	  low = GEN_INT (INTVAL (value) & word_mask);
-	  high = GEN_INT ((INTVAL (value) >> (shift_count + 1)) & word_mask);
+
+	  low = GEN_INT (INTVAL (value) << (HOST_BITS_PER_WIDE_INT - BITS_PER_WORD) >> (HOST_BITS_PER_WIDE_INT - BITS_PER_WORD));
+	  high = GEN_INT (INTVAL (value) << (HOST_BITS_PER_WIDE_INT - 2 * BITS_PER_WORD) >> (HOST_BITS_PER_WIDE_INT - BITS_PER_WORD));
 	  if (WORDS_BIG_ENDIAN)
 	    {
 	      *first = high;