Re: sqrt C function
* Craig Dickson (crdic@yahoo.com) spake thusly:
...
> (2) Is there any essential difference between the following two
> declarations:
>
> double f = 4;
> double f = 4.0;
>
> such that a conforming C compiler is prohibited from compiling them
^^^^^^^^^^ ^^^^^^^^^^
> to identical object code?
Sorry, Craig, WTF cares what "a conforming" compiler is "not prohibited"
to do? The question is "is my 'now even more standards-compliant than ever'
compiler *guaranteed* to *always* compile that to identical object code?"
AFAICT float f = 4.0; tells the compiler to assign floating-point value
of 4.0 to f. float f = 4; tells it to take integer value of 4, make a
float out of it, and assign the result to f. Your compiler may do it
right, and your code may never be compiled with another compiler.
Unfortunately, "may" != "always will".
My point, which you seem to have missed, was "given the choice between
explicitly specifying something and trusting the compiler to do the
right thing, always choose the former". That 4.0000000001234 crap was
just an example off the top of my head -- sorry if it confused you.
Dima
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