> As to the contention that the best C compilers can somehow best an
> experienced Assembly programmer, well, I'll leave that open to debate. =20

I like to consider myself an "experienced" assembly programmer (at least th=
e
gray hair on my head would serve to indicate so).

I had a project on a PIC24 that required the implementation of TEA (tiny
encryption algorithm). This algorithm consists of a lot of shifting,
rotating and bit twiddling, and, with speed of the essence, I thought it
wise to code in assembly. After spending way too much time on it, I was abl=
e
to come up with a version that kept all the working variables in registers,
using every single register except the stack pointer. It ran fast, and I wa=
s
very proud of my work. Curiosity overtook me and I decided to see what the
compiler would do with it. I quickly cobbled up a C version of it, without
much regard to efficiency. To my surprise the compiler's code was
substantially identical to mine (modulo storing things in different
registers). It spilled one variable to the stack, and missed a few details,
but its run time was only 15% slower than my very carefully optimized code.

-- Bob Ammerman
RAm Systems

--=20
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