Expressions in initializers

Phil Lindsay philbo at dhw68k.cts.com
Wed Mar 13 14:27:37 AEST 1991


In article <1032 at caslon.cs.arizona.edu> dave at cs.arizona.edu (Dave P. Schaumann) writes:
>In article <1991Mar4.144939.8311 at ux1.cso.uiuc.edu> mcdonald at aries.scs.uiuc.edu (Doug McDonald) writes:
>>sqrt(2.0) is an expression. It CAN be evaluated at compile time. Perhaps
>>some people don't want to write compilers that do that (i.e. they are too
>>lazy), but it most certainly CAN be evaluated.
>>
>>Perhaps a different explanation is appropriate?
>
>You want to link the whole floating point library to the C compiler?
>
>First thing you need to realize is that there is no special, pre-defined
>function sqrt() in C.  (Suprise!!!)  The function sqrt lives in a link
>libarary.  As far as the C compiler knows, it's just another user-defined
>function.  So it can't really be evaluated at compile time.
>
The MSC compiler "knows" strcpy(), memcpy(), etc... The compiler produces
inline versions of these functions. Compile guru's will do almost anything
for speed.

-- 
Phil Lindsay - "Patents threaten future technology"
Internet: philbo at dhw68k.cts.com  Phone: Wrk7143852311 Hm7142891201
UUCP:     {spsd,zardox,felix}!dhw68k!philbo
USMAIL: 152A S. Cross Creek Rd, Orange, Ca. 92669



More information about the Comp.lang.c mailing list