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Re: c/2614: Error when calculating with long long int
- To: jacob dot schultz at barconet dot com
- Subject: Re: c/2614: Error when calculating with long long int
- From: <julian at YoMama dot Flewid dot COM>
- Date: Mon, 23 Apr 2001 16:25:58 +0200 (CEST)
- cc: gcc-bugs at gcc dot gnu dot org
Hi
> There seems to be a problem when calculating with long longs. In a
> program I need to mask a number of bits from a long long, but something
> goes wrong. The calculation
> ((1<<n)-1)&m returns zero when n is 32 or larger, even if bits are set
> in m. Both n and m are unsigned long long int.
> I've attached an example which illustrates the pwoblem.
The number 1 is of type int, so you get a zero if the left shift count is
larger than 31. Use a "ll" suffix to change the type to long long.
Julian