Source file src/github.com/chenzhuoyu/iasm/expr/ops.go

Documentation: github.com/chenzhuoyu/iasm/expr

     1  package expr
     2  
     3  import (
     4      `fmt`
     5  )
     6  
     7  func idiv(v int64, d int64) (int64, error) {
     8      if d != 0 {
     9          return v / d, nil
    10      } else {
    11          return 0, newRuntimeError("division by zero")
    12      }
    13  }
    14  
    15  func imod(v int64, d int64) (int64, error) {
    16      if d != 0 {
    17          return v % d, nil
    18      } else {
    19          return 0, newRuntimeError("division by zero")
    20      }
    21  }
    22  
    23  func ipow(v int64, e int64) (int64, error) {
    24      mul := v
    25      ret := int64(1)
    26  
    27      /* value must be 0 or positive */
    28      if v < 0 {
    29          return 0, newRuntimeError(fmt.Sprintf("negative base value: %d", v))
    30      }
    31  
    32      /* exponent must be non-negative */
    33      if e < 0 {
    34          return 0, newRuntimeError(fmt.Sprintf("negative exponent: %d", e))
    35      }
    36  
    37      /* fast power first round */
    38      if (e & 1) != 0 {
    39          ret *= mul
    40      }
    41  
    42      /* fast power remaining rounds */
    43      for e >>= 1; e != 0; e >>= 1 {
    44          if mul *= mul; (e & 1) != 0 {
    45              ret *= mul
    46          }
    47      }
    48  
    49      /* all done */
    50      return ret, nil
    51  }
    52  

View as plain text