openpower/isa/comparefixed.mdwn

   1 # Compare Immediate
   2
   3 cmpi BF,L,RA,SI
   4
   5     if L = 0 then a <-  EXTS((RA)[32:63])
   6              else a <-  (RA)
   7     if      a < EXTS(SI) then c <- 0b100
   8     else if a > EXTS(SI) then c <- 0b010
   9     else                      c <- 0b001
  10     CR[4*BF+32:4*BF+35] <- c || XER[SO]
  11
  12 # Compare
  13
  14 cmp BF,L,RA,RB
  15
  16     if L = 0 then a <-  EXTS((RA)[32:63] )
  17                     b <- EXTS((RB)[32:63])
  18                else a <- (RA)
  19                     b <- (RB)
  20     if      a < b then c <-  0b100
  21     else if a > b then c <-  0b010
  22     else               c <-  0b001
  23     CR[4*BF+32:4*BF+35] <-  c || XER[SO]
  24
  25 # Compare Logical Immediate
  26
  27 cmpli BF,L,RA,UI
  28
  29     if L = 0 then a <- [0]*32 || (RA)[32:63]
  30              else a <- (RA)
  31     if      a <u ( [0]*48 || UI) then c <- 0b100
  32     else if a >u ( [0]*48 || UI) then c <- 0b010
  33     else                         c <- 0b001
  34     CR[4*BF+32:4*BF+35] <- c || XER[SO]
  35
  36 # Compare Logical
  37
  38 cmpl BF,L,RA,RB
  39
  40     if L = 0 then a <- [0]*32 || (RA)[32:63]
  41                   b <- [0]*32 || (RB)[32:63]
  42              else a <-  (RA)
  43                   b <-  (RB)
  44     if      a <u b then c <- 0b100
  45     else if a >u b then c <- 0b010
  46     else                c <-  0b001
  47     CR[4*BF+32:4*BF+35] <- c || XER[SO]
  48
  49 # Compare Ranged Byte X-form
  50
  51 cmprb BF,L,RA,RB
  52
  53     src1    <- EXTZ((RA)[56:63])
  54
  55     src21hi <- EXTZ((RB)[32:39])
  56     src21lo <- EXTZ((RB)[40:47])
  57     src22hi <- EXTZ((RB)[48:55])
  58     src22lo <- EXTZ((RB)[56:63])
  59
  60     if L=0 then
  61        in_range <-  (src22lo  <= src1) & (src1 <=  src22hi)
  62     else
  63        in_range <- ((src21lo  <= src1) & (src1 <=  src21hi)) |
  64        in_range <- ((src22lo  <= src1) & (src1 <=  src22hi))
  65
  66     CR[4×BF+32] <- 0b0
  67     CR[4×BF+33] <- in_range
  68     CR[4×BF+34] <- 0b0
  69     CR[4×BF+35] <- 0b0
  70
  71 # Compare Equal Byte X-form
  72
  73 cmpeqb BF,RA,RB
  74
  75     src1 <- GPR[RA].bit[56:63]
  76
  77     match <- (src1 = (RB)[00:07]) |
  78     match <- (src1 = (RB)[08:15]) |
  79     match <- (src1 = (RB)[16:23]) |
  80     match <- (src1 = (RB)[24:31]) |
  81     match <- (src1 = (RB)[32:39]) |
  82     match <- (src1 = (RB)[40:47]) |
  83     match <- (src1 = (RB)[48:55]) |
  84     match <- (src1 = (RB)[56:63])
  85
  86     CR[4×BF+32] <- 0b0
  87     CR[4×BF+33] <- match
  88     CR[4×BF+34] <- 0b0
  89     CR[4×BF+35] <- 0b0
  90