Changes between Version 4 and Version 5 of IDISA_Horizontal


Ignore:
Timestamp:
May 9, 2011, 6:29:57 AM (8 years ago)
Author:
cameron
Comment:

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  • IDISA_Horizontal

    v4 v5  
    44fields, together with their description and semantic specification.
    55
    6 These operations generally have the form `r = hsimd<N>::op(a, b)` for each
     6These operations generally have the form `r = hsimd<w>::op(a, b)` for each
    77operation `op`, where `a` and `b` are operand vectors of N bit fields and `r` is
    88the corresponding result vector.   
    99
    10 In general, operand fields may be interpreted as either signed or unsigned N-bit
     10In general, operand fields may be interpreted as either signed or unsigned ''w''-bit
    1111integers, depending on the operation.   When the results depend on
    1212this interpretation, the notation s(a) refers to the interpretation
     
    2525|| `packss` || pack with signed saturation || r,,i,, = ss,,N,,(concat(c,,2i,,, c,,2i+1,,)) ||
    2626
    27 where the N-bit unsigned and signed saturation functions are defined as follows.
    28  - us,,N,,(x) = x, if u(x) < 2^N^
    29  - us,,N,,(x) = 2^N^-1, if u(x) >= 2^N^
    30  - ss,,N,,(x) = x, if -2^N-1^ <= s(x) < 2^N-1^
    31  - ss,,N,,(x) = 2^N-1^-1, if s(x) >= 2^N-1^
    32  - ss,,N,,(x) = -2^N-1^, if s(x) < 2^N-1^
     27where the ''w''-bit unsigned and signed saturation functions are defined as follows.
     28 - us,,''w'',,(x) = x, if u(x) < 2^''w''^
     29 - us,,''w'',,(x) = 2^''w''^-1, if u(x) >= 2^''w''^
     30 - ss,,''w'',,(x) = x, if -2^''w''-1^ <= s(x) < 2^''w''-1^
     31 - ss,,''w'',,(x) = 2^''w''-1^-1, if s(x) >= 2^''w''-1^
     32 - ss,,''w'',,(x) = -2^''w''-1^, if s(x) < 2^''w''-1^
    3333
    3434In these definitions, fields are numbered left-to-right in so-called *big-endian*