28 lines
1.5 KiB
Fortran
28 lines
1.5 KiB
Fortran
integer :: i, j = -1, k = 42
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logical :: a
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i = bit_size(j) ! returns the number of bits in the given INTEGER variable
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! bitwise boolean operations on integers
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i = iand(k, j) ! returns bitwise AND of K and J
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i = ior(k, j) ! returns bitwise OR of K and J
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i = ieor(k, j) ! returns bitwise EXCLUSIVE OR of K and J
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i = not(j) ! returns bitwise NOT of J
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! single-bit integer/logical operations (bit positions are zero-based)
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a = btest(i, 4) ! returns logical .TRUE. if bit position 4 of I is 1, .FALSE. if 0
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i = ibclr(k, 8) ! returns value of K with 8th bit position "cleared" (set to 0)
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i = ibset(k, 13) ! returns value of K with 13th bit position "set" (set to 1)
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! multi-bit integer operations
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i = ishft(k, j) ! returns value of K shifted by J bit positions, with ZERO fill
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! (right shift if J < 0 and left shift if J > 0).
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i = ishftc(k, j) ! returns value of K shifted CIRCULARLY by J bit positions
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! (right circular shift if J < 0 and left if J > 0)
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i = ishftc(k, j, 20) ! returns value as before except that ONLY the 20 lowest order
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! (rightmost) bits are circularly shifted
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i = ibits(k, 7, 8) ! extracts 8 contiguous bits from K starting at position 7 and
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! returns them as the rightmost bits of an otherwise
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! zero-filled integer. For non-negative K this is
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! arithmetically equivalent to: MOD((K / 2**7), 2**8)
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