openpower/isa/comparefixed.mdwn

   1 # Compare Immediate
   2
   3 D-Form
   4
   5 * cmpi BF,L,RA,SI
   6
   7 Pseudo-code:
   8
   9     if L = 0 then a <-  EXTS((RA)[32:63])
  10     else a <-  (RA)
  11     if      a < EXTS(SI) then c <- 0b100
  12     else if a > EXTS(SI) then c <- 0b010
  13     else                      c <- 0b001
  14     CR[4*BF+32:4*BF+35] <- c || XER[SO]
  15
  16 Special Registers Altered:
  17
  18     CR field BF
  19
  20 # Compare
  21
  22 X-Form
  23
  24 * cmp BF,L,RA,RB
  25
  26 Pseudo-code:
  27
  28     if L = 0 then
  29         a <-  EXTS((RA)[32:63] )
  30         b <- EXTS((RB)[32:63])
  31     else
  32         a <- (RA)
  33         b <- (RB)
  34     if      a < b then c <-  0b100
  35     else if a > b then c <-  0b010
  36     else               c <-  0b001
  37     CR[4*BF+32:4*BF+35] <-  c || XER[SO]
  38
  39 Special Registers Altered:
  40
  41     CR field BF
  42
  43 # Compare Logical Immediate
  44
  45 D-Form
  46
  47 * cmpli BF,L,RA,UI
  48
  49 Pseudo-code:
  50
  51     if L = 0 then a <- [0]*32 || (RA)[32:63]
  52     else a <- (RA)
  53     if      a <u ( [0]*48 || UI) then c <- 0b100
  54     else if a >u ( [0]*48 || UI) then c <- 0b010
  55     else                         c <- 0b001
  56     CR[4*BF+32:4*BF+35] <- c || XER[SO]
  57
  58 Special Registers Altered:
  59
  60     CR field BF
  61
  62 # Compare Logical
  63
  64 X-Form
  65
  66 * cmpl BF,L,RA,RB
  67
  68 Pseudo-code:
  69
  70     if L = 0 then
  71         a <- [0]*32 || (RA)[32:63]
  72         b <- [0]*32 || (RB)[32:63]
  73     else
  74         a <-  (RA)
  75         b <-  (RB)
  76     if      a <u b then c <- 0b100
  77     else if a >u b then c <- 0b010
  78     else                c <-  0b001
  79     CR[4*BF+32:4*BF+35] <- c || XER[SO]
  80
  81 Special Registers Altered:
  82
  83     CR field BF
  84
  85 # Compare Ranged Byte
  86
  87 X-Form
  88
  89 * cmprb BF,L,RA,RB
  90
  91 Pseudo-code:
  92
  93     src1    <- EXTZ((RA)[56:63])
  94     src21hi <- EXTZ((RB)[32:39])
  95     src21lo <- EXTZ((RB)[40:47])
  96     src22hi <- EXTZ((RB)[48:55])
  97     src22lo <- EXTZ((RB)[56:63])
  98     if L=0 then
  99        in_range <-  (src22lo  <= src1) & (src1 <=  src22hi)
 100     else
 101        in_range <- (((src21lo  <= src1) & (src1 <=  src21hi)) |
 102                     ((src22lo  <= src1) & (src1 <=  src22hi)))
 103     CR[4*BF+32] <- 0b0
 104     CR[4*BF+33] <- in_range
 105     CR[4*BF+34] <- 0b0
 106     CR[4*BF+35] <- 0b0
 107
 108 Special Registers Altered:
 109
 110     CR field BF
 111
 112 # Compare Equal Byte
 113
 114 X-Form
 115
 116 * cmpeqb BF,RA,RB
 117
 118 Pseudo-code:
 119
 120     src1 <- GPR[RA]
 121     src1 <- src1[56:63]
 122     match <- ((src1 = (RB)[00:07]) |
 123               (src1 = (RB)[08:15]) |
 124               (src1 = (RB)[16:23]) |
 125               (src1 = (RB)[24:31]) |
 126               (src1 = (RB)[32:39]) |
 127               (src1 = (RB)[40:47]) |
 128               (src1 = (RB)[48:55]) |
 129               (src1 = (RB)[56:63]))
 130     CR[4*BF+32] <- 0b0
 131     CR[4*BF+33] <- match
 132     CR[4*BF+34] <- 0b0
 133     CR[4*BF+35] <- 0b0
 134
 135 Special Registers Altered:
 136
 137     CR field BF
 138