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subroutine gdcp2i(n, itab, m)
c!purpose
c decomposition of an integer n in a base tw0.
c n=a1+a2*2+a3*2**2+.........+am*2**(m-1).
c!calling sequence
c subroutine gdcp2i(n,itab,m)
c integer n,itab,m
c
c n : integer to be decomposed (n.le.32767)
c
c itab :logical vector of dimension 15.
c in output: if(a(i-1).ne.0)then itab(i)=.true.
c else itab(i)=.false.
c
c m :the number of itab elements to be consider in output.
c
c!originator
c j. hanen -september 1978-ensm-nantes.
c!
c
dimension ipow2(15)
logical itab(*)
c
data ipow2(1), ipow2(2), ipow2(3), ipow2(4), ipow2(5),
* ipow2(6), ipow2(7), ipow2(8), ipow2(9), ipow2(10),
* ipow2(11), ipow2(12), ipow2(13), ipow2(14), ipow2(15)
* /16384,8192,4096,2048,1024,512,256,128,64,32,16,8,4,2,1/
c
m = 0
k = 15
nn = abs(n)
if (nn.gt.32767) nn = mod(nn,32767)
do 30 i=1,15
if (nn.lt.ipow2(i)) go to 10
itab(k) = .true.
nn = nn - ipow2(i)
if (m.eq.0) m = k
go to 20
10 itab(k) = .false.
20 k = k - 1
30 continue
c
return
end
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