roy@sts.sts.UUCP (06/23/89)
I would like to find out about the IEEE floating point format and,
specifically, about the "hidden bit". I do know that, for example,
the number 1 would be represented with a sign of 0, exponent (excess
127) of 127 and a fractional part of 0. I just don't have access to
any papers on the IEEE format or understand (by example) the concept
of the "hidden bit". Any pointers to appropriate places to look for
information or tips on hidden bits would be appreciated. Thanks!
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Roy Bixler | UUCP: ...!{claris,sun}!sts!roy |
Semiconductor Test Solutions | Internet: sts!roy@Claris.COM |
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==================================================================brooks@vette.llnl.gov (Eugene Brooks) (06/23/89)
In article <67700005@sts> roy@sts.sts.UUCP writes: > >I would like to find out about the IEEE floating point format and, >specifically, about the "hidden bit". I do know that, for example, The situation is very simple. All normalized numbers either have a 1 bit as the most significant bit or are ZERO. ZERO is the special 32 or 64 bit word of all zero bits, and all other normalized numbers have in the most significant bit slot a 1 so we don't bother chewing up a bit of memory for it. We get one more significant bit for the mantessa for our trouble. This bit which is not present in the memory representation is called the hidden bit, and it gets stuck back in and taken back out as things go in and out of the functional units. For a denormalized floating point number, the hidden bit is, you guessed it, a 0. brooks@maddog.llnl.gov, brooks@maddog.uucp
johnl@ima.ima.isc.com (John R. Levine) (06/25/89)
In article <67700005@sts> roy@sts.sts.UUCP writes: >I would like to find out about the IEEE floating point format ... You can buy the standard directly from the IEEE. It is surprisingly short and readable. Call them at 800-678-IEEE and order standard number 754-1985. It costs $15.00 plus $4 p/h, half price for IEEE members. -- John R. Levine, Segue Software, POB 349, Cambridge MA 02238, +1 617 492 3869 { bbn | spdcc | decvax | harvard | yale }!ima!johnl, Levine@YALE.something Massachusetts has 64 licensed drivers who are over 100 years old. -The Globe