Path: utzoo!utgpu!water!watmath!clyde!rutgers!husc6!cmcl2!brl-adm!adm!weiser.pa@Xerox.COM
From: weiser.pa@Xerox.COM
Newsgroups: comp.unix.wizards
Subject: casting to float without converting to float?
Message-ID: <11171@brl-adm.ARPA>
Date: 7 Jan 88 20:57:56 GMT
Sender: news@brl-adm.ARPA
Lines: 19

I have the following problem:  I have a value which I happen to know has the
proper bits to represent a floating point number (either 32 or 64).  However, it
is of type int.  I would now like to tell the C compiler to treat this thing as
a float.  How can I do it without taking the address of the thing (which may not
have an address because it is in a register or is an expression) or using a
subroutine call (for which I do not wish to pay the cost)?

(If I could take an address, then the solution is: *(float *)foo).)

(Needless to say, the following does NOT work: (float)foo, because it actually
does a conversion of the integer foo into a float.  I don't want a conversion,
but rather I want the compiler to just trust me that I am handing it bits that
it should consider to be a float.)

Thanks for any help.  Currently I'm working around the problem by using
assembler in-lines as supported by Sun, but I'd like a less vendor independent
method. 

-mark