I think of a nand-function.
On 29-07-19 02:51, Henry Rich wrote:
Many of the members of this Forum will remember the days of assembler
language
...and who could less than merry be
when writing out BXLE?
AND, OR, XOR were our meat. Those days are returning.
You have two integer variables
I am missing something:
a == 0 iff popcnt(a) == 0, so indeed
a == 0 || b == 0
is equivalent to
popcnt(a) == 0 || popcnt(b) == 0
which can be written as
!(popcnt(a) && popcnt(b)),
but if this is translated into a single-branch sequence of machine
instructions, then wouldn’t
!(a && b)
be as well?
T
If you have thought about this for a year then the following can't be the
answer, but here it is:
There is either a popcnt instruction, or you can implement it with
straight-line code without branching. Whence:
if !(popcnt(a)&&popcnt(b)) stmt;
On Sun, Jul 28, 2019 at 5:51 PM Henry Rich wrote:
How about multiply a and b, followed by a branch on zero?
~ Gilles
Le 2019-07-28 à 20:51, Henry Rich a écrit :
> Many of the members of this Forum will remember the days of assembler
> language
>
> ...and who could less than merry be
> when writing out BXLE?
>
> AND, OR, XOR were our meat. T
Do we have access to an instruction which counts leading zero bits?
Interesting problem,
Louis
> On 28 Jul 2019, at 19:51, Henry Rich wrote:
>
> Many of the members of this Forum will remember the days of assembler language
>
> ...and who could less than merry be
> when writing out BXLE?
>
Many of the members of this Forum will remember the days of assembler
language
...and who could less than merry be
when writing out BXLE?
AND, OR, XOR were our meat. Those days are returning.
You have two integer variables a and b and you want to do something if
one or both of them are 0
