search for: simplfiying

FWIW, I believe icc -O3 turns on the equivalent of -ffast-math by default. I could be misremembering which compilers do this though :) This flag allows you to make all kinds of nice simplfiying assumptions about floating point. On Thu, Jan 8, 2009 at 7:45 PM, Owen Anderson <resistor at mac.com> wrote: > I assume it checks that the end condition and the increment can both > be represented precisely with integer types. > > --Owen > > On Jan 8, 2009, at 9:49 AM, Mart...

I assume it checks that the end condition and the increment can both be represented precisely with integer types. --Owen On Jan 8, 2009, at 9:49 AM, Martin Geisse wrote: > Isn't "simplifying" the loop index to an integer also dependent on > precision issues? The following loop is infinite: > > for (float i=0.0; i<...; i+=1.0) {} > > where ... is a large

...jne L2 -- Syoyo On Fri, Jan 9, 2009 at 1:11 PM, Daniel Berlin <dberlin at dberlin.org> wrote: > FWIW, I believe icc -O3 turns on the equivalent of -ffast-math by default. > I could be misremembering which compilers do this though :) > This flag allows you to make all kinds of nice simplfiying assumptions > about floating point. > > On Thu, Jan 8, 2009 at 7:45 PM, Owen Anderson <resistor at mac.com> wrote: >> I assume it checks that the end condition and the increment can both >> be represented precisely with integer types. >> >> --Owen >> &gt...

Isn't "simplifying" the loop index to an integer also dependent on precision issues? The following loop is infinite: for (float i=0.0; i<...; i+=1.0) {} where ... is a large "integral" float literal, e.g. 2^40. At some point, adding 1.0 to the loop index would not cause any changes because of precision issues. However, if the float type is replaced by some