openpower/isa/av.mdwn

   1 <!-- DRAFT Instructions for PowerISA Version 3.0 B Book 1 -->
   2 <!-- https://libre-soc.org/openpower/sv/bitmanip/ -->
   3 <!-- https://libre-soc.org/openpower/sv/av_opcodes/ -->
   4
   5 # DRAFT Fixed Point Signed Max
   6
   7 X-Form
   8
   9 * maxs  RT,RA,RB (Rc=0)
  10 * maxs. RT,RA,RB (Rc=1)
  11
  12 Pseudo-code:
  13
  14     if   (RA) > (RB) then RT <- (RA)
  15     else                  RT <- (RB)
  16
  17 Special Registers Altered:
  18
  19     CR0                     (if Rc=1)
  20
  21 # DRAFT Fixed Point Unsigned Max
  22
  23 X-Form
  24
  25 * maxu  RT,RA,RB (Rc=0)
  26 * maxu. RT,RA,RB (Rc=1)
  27
  28 Pseudo-code:
  29
  30     if   (RA) >u (RB) then RT <- (RA)
  31     else                   RT <- (RB)
  32
  33 Special Registers Altered:
  34
  35     CR0                     (if Rc=1)
  36
  37 # DRAFT Fixed Point Signed Min
  38
  39 X-Form
  40
  41 * mins  RT,RA,RB (Rc=0)
  42 * mins. RT,RA,RB (Rc=1)
  43
  44 Pseudo-code:
  45
  46     if   (RA) < (RB) then RT <- (RA)
  47     else                  RT <- (RB)
  48
  49 Special Registers Altered:
  50
  51     CR0                     (if Rc=1)
  52
  53 # DRAFT Fixed Point Unsigned Min
  54
  55 X-Form
  56
  57 * minu  RT,RA,RB (Rc=0)
  58 * minu. RT,RA,RB (Rc=1)
  59
  60 Pseudo-code:
  61
  62     if   (RA) < (RB) then RT <- (RA)
  63     else                  RT <- (RB)
  64
  65 Special Registers Altered:
  66
  67     CR0                     (if Rc=1)
  68
  69 # DRAFT Average Add
  70
  71 X-Form
  72
  73 * avgadd  RT,RA,RB (Rc=0)
  74 * avgadd. RT,RA,RB (Rc=1)
  75
  76 Pseudo-code:
  77
  78     a <- [0] * (XLEN+1)
  79     b <- [0] * (XLEN+1)
  80     a[1:XLEN] <- (RA)
  81     b[1:XLEN] <- (RB)
  82     r <- (a + b + 1)
  83     RT <- r[0:XLEN-1]
  84
  85 Special Registers Altered:
  86
  87     CR0                     (if Rc=1)
  88
  89 # DRAFT Absolute Unsigned Difference
  90
  91 X-Form
  92
  93 * absdu  RT,RA,RB (Rc=0)
  94 * absdu. RT,RA,RB (Rc=1)
  95
  96 Pseudo-code:
  97
  98     if (RA) < (RB) then RT <- ¬(RA) + (RB) + 1
  99     else                RT <- ¬(RB) + (RA) + 1
 100
 101 Special Registers Altered:
 102
 103     CR0                     (if Rc=1)
 104
 105 # DRAFT Absolute Accumulate Unsigned Difference
 106
 107 X-Form
 108
 109 * absaddu  RT,RA,RB (Rc=0)
 110 * absaddu. RT,RA,RB (Rc=1)
 111
 112 Pseudo-code:
 113
 114     if (RA) <u (RB) then r <- ¬(RA) + (RB) + 1
 115     else                 r <- ¬(RB) + (RA) + 1
 116     RT <- (RT) + r
 117
 118 Special Registers Altered:
 119
 120     CR0                     (if Rc=1)