openpower/isa/bitmanip.mdwn

   1 <!-- Draft Instructions here described in https://libre-soc.org/openpower/sv/bitmanip/ -->
   2 <!-- These instructions are *not yet official* -->
   3
   4 # Ternary Bitwise Logic Immediate
   5
   6 TLI-Form
   7
   8 * ternlogi RT, RA, RB, TLI
   9
  10 Pseudo-code:
  11
  12     result <- [0] * XLEN
  13     do i = 0 to XLEN - 1
  14       idx <- (RT)[i] || (RA)[i] || (RB)[i]
  15       result[i] <- TLI[7-idx]
  16     RT <- result
  17
  18 Special Registers Altered:
  19
  20     None
  21
  22 # Generalized Bit-Reverse
  23
  24 X-Form
  25
  26 * grev RT, RA, RB (Rc=0)
  27 * grev. RT, RA, RB (Rc=1)
  28
  29 Pseudo-code:
  30
  31     result <- [0] * XLEN
  32     b <- EXTZ64(RB)
  33     do i = 0 to XLEN - 1
  34       idx <- b[64-log2(XLEN):63] ^ i
  35       result[i] <- (RA)[idx]
  36     RT <- result
  37
  38 Special Registers Altered:
  39
  40     CR0                    (if Rc=1)
  41
  42 # Generalized Bit-Reverse Immediate
  43
  44 XB-Form
  45
  46 * grevi RT, RA, XBI (Rc=0)
  47 * grevi. RT, RA, XBI (Rc=1)
  48
  49 Pseudo-code:
  50
  51     result <- [0] * XLEN
  52     do i = 0 to XLEN - 1
  53       idx <- XBI[6-log2(XLEN):5] ^ i
  54       result[i] <- (RA)[idx]
  55     RT <- result
  56
  57 Special Registers Altered:
  58
  59     CR0                    (if Rc=1)
  60
  61 # Generalized Bit-Reverse Word
  62
  63 X-Form
  64
  65 * grevw RT, RA, RB (Rc=0)
  66 * grevw. RT, RA, RB (Rc=1)
  67
  68 Pseudo-code:
  69
  70     result <- [0] * (XLEN / 2)
  71     a <- (RA)[XLEN/2:XLEN-1]
  72     b <- EXTZ64(RB)
  73     do i = 0 to XLEN / 2 - 1
  74       idx <- b[64-log2(XLEN/2):63] ^ i
  75       result[i] <- a[idx]
  76     RT <- ([0] * (XLEN / 2)) || result
  77
  78 Special Registers Altered:
  79
  80     CR0                    (if Rc=1)
  81
  82 # Generalized Bit-Reverse Word Immediate
  83
  84 X-Form
  85
  86 * grevwi RT, RA, SH (Rc=0)
  87 * grevwi. RT, RA, SH (Rc=1)
  88
  89 Pseudo-code:
  90
  91     result <- [0] * (XLEN / 2)
  92     a <- (RA)[XLEN/2:XLEN-1]
  93     do i = 0 to XLEN / 2 - 1
  94       idx <- SH[5-log2(XLEN/2):4] ^ i
  95       result[i] <- a[idx]
  96     RT <- ([0] * (XLEN / 2)) || result
  97
  98 Special Registers Altered:
  99
 100     CR0                    (if Rc=1)