Thu Sep 2 00:06:43 1999 Jeffrey A Law (law@cygnus.com)
+ * combine.c (simplify_rtx): Recognize another case of a synthesized
+ sign extension.
+
* varasm.c (mark_constant_pool): When marking indirect references,
only look at SYMBOL_REFs.
/* (plus (xor (and <foo> (const_int pow2 - 1)) <c>) <-c>)
when c is (const_int (pow2 + 1) / 2) is a sign extension of a
bit-field and can be replaced by either a sign_extend or a
- sign_extract. The `and' may be a zero_extend. */
+ sign_extract. The `and' may be a zero_extend and the two
+ <c>, -<c> constants may be reversed. */
if (GET_CODE (XEXP (x, 0)) == XOR
&& GET_CODE (XEXP (x, 1)) == CONST_INT
&& GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT
&& INTVAL (XEXP (x, 1)) == - INTVAL (XEXP (XEXP (x, 0), 1))
- && (i = exact_log2 (INTVAL (XEXP (XEXP (x, 0), 1)))) >= 0
+ && ((i = exact_log2 (INTVAL (XEXP (XEXP (x, 0), 1)))) >= 0
+ || (i = exact_log2 (INTVAL (XEXP (x, 1)))) >= 0)
&& GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT
&& ((GET_CODE (XEXP (XEXP (x, 0), 0)) == AND
&& GET_CODE (XEXP (XEXP (XEXP (x, 0), 0), 1)) == CONST_INT