[Python-checkins] python/dist/src/Objects longobject.c,1.141,1.142

[tim_one@users.sourceforge.net]

Update of /cvsroot/python/python/dist/src/Objects
In directory usw-pr-cvs1:/tmp/cvs-serv12415/python/Objects

Modified Files:
	longobject.c 
Log Message:
long_format(), long_lshift():  Someone on c.l.py is trying to boost
SHIFT and MASK, and widen digit.  One problem is that code of the form

    digit << small_integer

implicitly assumes that the result fits in an int or unsigned int
(platform-dependent, but "int sized" in any case), since digit is
promoted "just" to int or unsigned via the usual integer promotions.
But if digit is typedef'ed as unsigned int, this loses information.
The cure for this is just to cast digit to twodigits first.


Index: longobject.c
===================================================================
RCS file: /cvsroot/python/python/dist/src/Objects/longobject.c,v
retrieving revision 1.141
retrieving revision 1.142
diff -C2 -d -r1.141 -r1.142
*** longobject.c	15 Aug 2002 20:10:45 -0000	1.141
--- longobject.c	20 Aug 2002 19:00:22 -0000	1.142
***************
*** 950,954 ****
  
  		for (i = 0; i < size_a; ++i) {
! 			accum |= a->ob_digit[i] << accumbits;
  			accumbits += SHIFT;
  			assert(accumbits >= basebits);
--- 950,954 ----
  
  		for (i = 0; i < size_a; ++i) {
! 			accum |= (twodigits)a->ob_digit[i] << accumbits;
  			accumbits += SHIFT;
  			assert(accumbits >= basebits);
***************
*** 2346,2350 ****
  	accum = 0;
  	for (i = wordshift, j = 0; j < oldsize; i++, j++) {
! 		accum |= a->ob_digit[j] << remshift;
  		z->ob_digit[i] = (digit)(accum & MASK);
  		accum >>= SHIFT;
--- 2346,2350 ----
  	accum = 0;
  	for (i = wordshift, j = 0; j < oldsize; i++, j++) {
! 		accum |= (twodigits)a->ob_digit[j] << remshift;
  		z->ob_digit[i] = (digit)(accum & MASK);
  		accum >>= SHIFT;