ops.go

Documentation: github.com/cloudwego/iasm/expr

     1  //
     2  // Copyright 2024 CloudWeGo Authors
     3  //
     4  // Licensed under the Apache License, Version 2.0 (the "License");
     5  // you may not use this file except in compliance with the License.
     6  // You may obtain a copy of the License at
     7  //
     8  //     http://www.apache.org/licenses/LICENSE-2.0
     9  //
    10  // Unless required by applicable law or agreed to in writing, software
    11  // distributed under the License is distributed on an "AS IS" BASIS,
    12  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  // See the License for the specific language governing permissions and
    14  // limitations under the License.
    15  //
    16  
    17  package expr
    18  
    19  import (
    20      `fmt`
    21  )
    22  
    23  func idiv(v int64, d int64) (int64, error) {
    24      if d != 0 {
    25          return v / d, nil
    26      } else {
    27          return 0, newRuntimeError("division by zero")
    28      }
    29  }
    30  
    31  func imod(v int64, d int64) (int64, error) {
    32      if d != 0 {
    33          return v % d, nil
    34      } else {
    35          return 0, newRuntimeError("division by zero")
    36      }
    37  }
    38  
    39  func ipow(v int64, e int64) (int64, error) {
    40      mul := v
    41      ret := int64(1)
    42  
    43      /* value must be 0 or positive */
    44      if v < 0 {
    45          return 0, newRuntimeError(fmt.Sprintf("negative base value: %d", v))
    46      }
    47  
    48      /* exponent must be non-negative */
    49      if e < 0 {
    50          return 0, newRuntimeError(fmt.Sprintf("negative exponent: %d", e))
    51      }
    52  
    53      /* fast power first round */
    54      if (e & 1) != 0 {
    55          ret *= mul
    56      }
    57  
    58      /* fast power remaining rounds */
    59      for e >>= 1; e != 0; e >>= 1 {
    60          if mul *= mul; (e & 1) != 0 {
    61              ret *= mul
    62          }
    63      }
    64  
    65      /* all done */
    66      return ret, nil
    67  }
    68
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