Author: Heiner Marxen
Date: 12:54:16 10/05/02
Go up one level in this thread
On October 05, 2002 at 14:38:12, Antonio Dieguez wrote: >hi, dumb question. In a book i saw when using the >> operator, with signed >numbers, it is dependant on the machine if it is filled the left with 0 or 1. I >supossed it were always 0. May be in practice it is always 0 in pcs, is that the >case? should i be worried about? It depends on the type and possibly the value of the (left) operand: unsigned >> does always fill (high) zeroes (halving the value) signed non-negative value >> does also fill zeroes. Both is guaranteed by ANSI-C (6.3.7). Doing a >> with a negative value is "implementation defined". Mostly it fills the sign bit, i.e. a 1-bit. That is similar to halving the value (except for -1). But you cannot (portably) rely on this behaviour. Shifting is best done with unsigned quantities. >thank you. Cheers, Heiner
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.