Assembly or ....

[John Mashey]

In article <1032 at l.cc.purdue.edu> cik at l.cc.purdue.edu (Herman Rubin) writes:
...
>Another effect of the HLL tyranny is that the operations which are beyond
>the ken of th HLL designers are disappearing from the machines.  Other
>useful operations are not getting in.  For example, suppose we want to
>divide a by b, obtaining an integer result i and a remainder c.  I know
>of no machine with this instruction, and this is not that unusual an 
>instruction to demand.  It is cheap in hardware, and extremely expensive
>in software--at least 4 instructions.

Although I don't necessarily subscribe to Herman's opinions, R2000 divides
actually do this (leave both results in registers).  Although I shouldn't
have been, I was surprised to find that the following C code, compiled
unoptimized (optimized, it essentially disappears, of course):

main() {
	register i,j,k;
	i = j / 7;
	k = j % 7;
}

generates one divide instruction to get both of the results.
-- 
-john mashey	DISCLAIMER: <generic disclaimer, I speak for me only, etc>
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