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SubjectRe: floating-point abuse in 2.1.113
On Thu, 6 Aug 1998, Andi Kleen wrote:

> On Thu, Aug 06, 1998 at 03:23:01PM +0200, Richard B. Johnson wrote:
> > It seems that gcc does not treat a short procedure like a large one.
> > This may have something to do with resources available during a kernel
> > compile???
>
> If it is all contained in a single expression that is very unlikely.
> fold-const operates on "tree"s build by the frontend for single expressions,
> and it does not depend much on context.
>
> For constant propagation it could make a difference, because the gcc backend
> works with the RTL abstraction then and depends on context (e.g. various
> optimizations are not done when the function contains gotos etc.)
>
> -Andi
>

In any event, the way to prevent unexplained compiler real-number
quirks from happening is don't use real-numbers in the kernel. That
was the whole point --and I see that a lot of the (int)(float)x.x...
is being removed and replaced with integer math, which is good(tm).

Cheers,
Dick Johnson
***** FILE SYSTEM MODIFIED *****
Penguin : Linux version 2.1.113 on an i586 machine (66.15 BogoMips).
Warning : It's hard to remain at the trailing edge of technology.


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