是SystemVerilog的阵列通过值或引用传递？ [英] Are SystemVerilog arrays passed by value or reference?

问题描述

默认情况下，值或引用则SystemVerilog的传递数组？

例如：

  int数组[5] ='{0,1,2,3,4};
some_function（数组）; //＆LT;  - 数值或引用？
 

解决方案

默认情况下，SystemVerilog的按值传递数组，复制整个数组。

建议参照尽可能通过阵列性能方面的原因。

• 如果你想你的函数修改数组，使用 REF 。


• 如果你想你的函数读取数组，使用 REF常量。

例如：

 函数void pass_by_value（int数组[5]，INT队列[$]，INT ASSOC [INT]）;
    //默认。
    //阵列的副本在这个函数是由
  endfunction可  函数void pass_by_ref（参考int数组[5]，文献INT队列[$]
                            REF INT ASSOC [INT]）;
    //原始阵列被引用
  endfunction可  函数void pass_by_const_ref（常量参考int数组[5]
                                  常量REF INT队列[$]
                                  常量REF INT assoc命令[INT]）;
    //原始阵列被引用
    //他们可以读，但不能在此函数修改
  endfunction可
 

在EDA游乐场举例： http://www.edaplayground.com/x/2m9

By default, does SystemVerilog pass arrays by value or reference?

For example:

int array[5] = '{0,1,2,3,4};
some_function(array);  // <-- value or reference?

解决方案

By default, SystemVerilog passes arrays by value, copying the entire array.

It is recommended to pass arrays by reference whenever possible for performance reasons.

• If you want your function to modify the array, use ref.
• If you want your function to read the array, use const ref.

Example:

  function void pass_by_value(int array[5], int queue[$], int assoc[int]);
    // Default.
    // A copy of the arrays is made in this function
  endfunction

  function void pass_by_ref(ref int array[5], ref int queue[$],
                            ref int assoc[int]);
    // Original arrays are being referenced
  endfunction

  function void pass_by_const_ref(const ref int array[5],
                                  const ref int queue[$],
                                  const ref int assoc[int]);
    // Original arrays are being referenced
    // And they can be read but cannot be modified in this function 
  endfunction

Example on EDA Playground: http://www.edaplayground.com/x/2m9

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