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!Program to test EXPONENT and FRACTION intrinsic function.
program test_exponent_fraction
real x
integer*4 i
real*8 y
integer*8 j
equivalence (x, i), (y, j)
x = 3.
call test_4(x)
x = 0.
call test_4(x)
i = o'00000000001'
call test_4(x)
i = o'00010000000'
call test_4(x)
i = o'17700000000'
call test_4(x)
i = o'00004000001'
call test_4(x)
i = o'17737777777'
call test_4(x)
i = o'10000000000'
call test_4(x)
i = o'0000010000'
call test_4(x)
y = 0.5
call test_8(y)
y = 0.
call test_8(y)
j = o'00000000001'
call test_8(y)
y = 0.2938735877D-38
call test_8(y)
y = -1.469369D-39
call test_8(y)
y = z'7fe00000'
call test_8(y)
y = -5.739719D+42
call test_8(y)
end
subroutine test_4(x)
real*4 x,y
integer z
y = fraction (x)
z = exponent(x)
if (z .gt. 0) then
y = (y * 2.) * (2. ** (z - 1))
else
y = (y / 2.) * (2. ** (z + 1))
end if
if (abs (x - y) .gt. spacing (max (abs (x), abs (y)))) call abort()
end
subroutine test_8(x)
real*8 x, y
integer z
y = fraction (x)
z = exponent(x)
if (z .gt. 0) then
y = (y * 2._8) * (2._8 ** (z - 1))
else
y = (y / 2._8) * (2._8 ** (z + 1))
end if
if (abs (x - y) .gt. spacing (max (abs (x), abs(y)))) call abort()
end
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