Subject: Re: shocking speed performance!
To: None <richard.earnshaw@arm.com>
From: None <kim@pvv.ntnu.no>
List: port-arm32
Date: 05/20/1999 14:15:40
> How can the system library efficiently implement atod or printf if it
> doesn't understand the underlying format?
Simple. Converting between text and floats is done by the math library,
which is changed.
> How can a compiler
> (particularly a cross compiler) optimise "double x = 1.0 + 33.5" if it
> doesn't know the rules for safe constant folding?
That is the job of the + operator, which is changed.
> How can an assembler
> (again, particularly a cross-assembler) generate the object implementation
> for .double 5.0 if it doesn't know the binary representation?
By being told how.
> In the end, something has to know what the translation between the binary
> and human formats are. I accept that there are too many user programs
> that abuse this ability to know; but many system programs *need* to know
> this in order to function correctly. There's no system call that will
> tell a compiler that the size of a double is 8, it just has to know this.
Which is why I worked on changing the compiler.
Kim0