You *can* do so:

x = x+y;
y = x-y;
x = x-y;

or for a longer discussion see this thread:

http://www.gamedev.net/community/forums/topic.asp?topic_id=98678

nomibegood

Author

nomibegood

Jun 13, 2002 at 4:54 AM

quote:
Original post by ALiENiD

    
x ^= y;
y ^= x;
x ^= y;

That should do it (it''s even faster than using a temporary value if I don''t recall wrong).

/ALiENiD

Thankyou very much for the reply ALiENiD I will try

nomibegood

Author

nomibegood

Jun 13, 2002 at 4:56 AM

quote:
Original post by felonius

You *can* do so:

x = x+y;
y = x-y;
x = x-y;

or for a longer discussion see this thread:

http://www.gamedev.net/community/forums/topic.asp?topic_id=98678

Thanks for the reply felonius

Serge K

Jun 13, 2002 at 11:52 PM

quote:
Original post by ALiENiD

    
x ^= y;
y ^= x;
x ^= y;

That should do it (it''s even faster than using a temporary value if I don''t recall wrong).

/ALiENiD

No, it''s not faster.
Any modern compiler can optimize away temporary variable and keep it all in the registers.
Swapping with XOR creates dependency between CPUs instructions - this code cannot be parallelized, which makes it bad for modern superscalar CPU.

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