Changes between Version 1 and Version 2 of IDISA_Vertical


Ignore:
Timestamp:
May 6, 2011, 11:13:46 AM (8 years ago)
Author:
cameron
Comment:

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  • IDISA_Vertical

    v1 v2  
    1616significant bits of x, ss(x) refers to conversion by signed
    1717saturation and us(x) refers to conversion by unsigned saturation.
    18 
    19 == IDISA Unary Operations ==
    20 
    21 These operations generally have the form `r = simd<N>::op(a)` for each
    22 operation `op`, where `a` is an operand vector of N bit fields and `r` is
    23 the corresponding result vector.   
    24 
    25 || `abs` || absolute value || r,,i,, = if s(a,,i,,) < 0 then -a,,i,, else a,,i,, ||
    26 || `neg` || negate || r,,i,, = -s(a,,i,,) ||
    27 || `popcount` || population count || r,,i,, = number of 1 bits in u(a,,i,,) ||
    28 || `ctz` || count trailing zeroes || r,,i,, = the number of consecutive 0 bits in a,,i,, counting from the right ||
    2918
    3019
     
    5140|| `sra` || shift right arithmetic || r,,i,, = s(a,,i,,) >> b,,i,,  ||
    5241
     42== IDISA Unary Operations ==
     43
     44These operations generally have the form `r = simd<N>::op(a)` for each
     45operation `op`, where `a` is an operand vector of N bit fields and `r` is
     46the corresponding result vector.   
     47
     48Some of these operations involve operations on the high half of each
     49field h(a,,i,,) and the the low half of each field l(a,,i,,), where
     50 - h(a,,i,,) = a,,i,, >> N/2
     51 - l(a,,i,,) = a,,i,, & (1 << N/2 - 1)
     52
     53|| `abs` || absolute value || r,,i,, = if s(a,,i,,) < 0 then -a,,i,, else a,,i,, ||
     54|| `neg` || negate || r,,i,, = -s(a,,i,,) ||
     55|| `add_hl` || add halves || r,,i,, = h(a,,i,,) + l(a,,i,,)
     56|| `xor_hl` || bitwise xor halves || r,,i,, = h(a,,i,,) xor l(a,,i,,)
     57|| `popcount` || population count || r,,i,, = number of 1 bits in u(a,,i,,) ||
     58|| `ctz` || count trailing zeroes || r,,i,, = the number of consecutive 0 bits in a,,i,, counting from the right ||
     59
     60
    5361== IDISA Ternary Operation ==
    5462