openpower/isa/branch.mdwn

   1 # Branch
   2
   3 b
   4 ba
   5 bl
   6 bla
   7
   8 target_addr
   9 target_addr
  10 target_addr
  11 target_addr
  12
  13 (AA=0 LK=0)
  14 (AA=1 LK=0)
  15 (AA=0 LK=1)
  16 (AA=1 LK=1)
  17
  18     if AA then NIA  <-iea EXTS(LI || 0b00)
  19     else       NIA  <-iea CIA + EXTS(LI || 0b00)
  20     if LK then LR <-iea  CIA + 4
  21
  22 # Branch Conditional
  23
  24 bc
  25 bca
  26 bcl
  27 bcla
  28
  29 BO,BI,target_addr
  30 BO,BI,target_addr
  31 BO,BI,target_addr
  32 BO,BI,target_addr
  33
  34 (AA=0 LK=0)
  35 (AA=1 LK=0)
  36 (AA=0 LK=1)
  37 (AA=1 LK=1)
  38
  39     if (64-bit mode)
  40       then M <- 0
  41       else M <- 32
  42     if ¬BO[2] then CTR <- CTR - 1
  43     ctr_ok <- BO[2] | ((CTR[M:63] != 0) ^ BO[3])
  44     cond_ok <- BO[0] | (CRBI+32 => BO[1])
  45     if ctr_ok & cond_ok then
  46       if AA then NIA <-iea EXTS(BD || 0b00)
  47       else       NIA <-iea CIA + EXTS(BD || 0b00)
  48     if LK then LR  <-iea  CIA + 4
  49
  50 # Branch Conditional to Link Register
  51
  52 XL-form
  53
  54 bclr
  55 bclrl
  56
  57 BO,BI,BH
  58 BO,BI,BH
  59
  60 (LK=0)
  61 (LK=1)
  62
  63     if (64-bit mode)
  64       then M <- 0
  65       else M <- 32
  66     if ¬BO[2]  then CTR <- CTR - 1
  67     ctr_ok <- BO[2] | ((CTR[M:63] != 0) ^ BO[3]
  68     cond_ok <- BO[0] | (CR[BI+32] =>  BO[1])
  69     if ctr_ok & cond_ok then NIA <- iea LR[0:61] || 0b00
  70     if LK then LR <-iea CIA + 4
  71
  72 # Branch Conditional to Count Register
  73
  74 bcctr
  75 bcctrl
  76
  77 BO,BI,BH
  78 BO,BI,BH
  79
  80 (LK=0)
  81 (LK=1)
  82
  83     cond_ok <- BO[0] | (CR[BI+32] => BO[1])
  84     if cond_ok then NIA <-iea CTR[0:61] || 0b00
  85     if LK then LR <- iea CIA + 4
  86
  87
  88 # Branch Conditional to Branch Target Address Register
  89
  90 bctar
  91 bctarl
  92
  93 BO,BI,BH
  94 BO,BI,BH
  95
  96 (LK=0)
  97 (LK=1)
  98
  99     if (64-bit mode)
 100       then M <- 0
 101       else M <- 32
 102     if ¬BO[2] then CTR <- CTR - 1
 103     ctr_ok <- BO[2]  | ((CTR[M:63] != 0) ^ BO[3]
 104     cond_ok <- BO[0] | (CR[BI+32] => BO[1])
 105     if ctr_ok & cond_ok then NIA <-iea TAR[0:61]  || 0b00
 106     if LK then LR <-iea  CIA + 4
 107