System Verilog (6) 数组操作

SV支持对数组内变量的 定位locator、排序ordering 和缩位 reduction

（1） 定位

find with, find_first with, find_last with 找的是数组内元素

find_index with, find_first_index with , find_last_index with 找的是索引号

查看代码

查看代码

module array_locator;
  int array[9] = '{1,2,3,4,5,6,7,8,9};
  int res[$];
  initial begin
    res= array.find (x) with (x>3);
    $display("find x with x>3: %p", res);
    
    res= array.find_first with (item<9 & item>2);
    $display("find_first with (item<9 & item>2): %p",res);

    res= array.find_last with (item<9 & item>=3);
    $display("find_last with item<9 & item>=3: %p",res);
    
    res= array.find_index with (item==3);
    $display("find_index with item==3: array[%0d]=3",res[0]);
    
    res= array.find_first_index(x) with (x>3);
    $display("find_first_index x with x>3: array[%0d]>3",res[0]);
    
    res= array.find_last_index(x) with (x<=4);
    $display("find_last_index x with x<=4: array[%0d]<=4",res[0]);
    
  end
endmodule

编译结果

# Loading sv_std.std
# Loading work.array_locator(fast)
# 
# vsim -voptargs=+acc=npr
# run -all
# find x with x>3: '{4, 5, 6, 7, 8, 9}
# find_first with (item<9 & item>2): '{3}
# find_last with item<9 & item>=3: '{8}
# find_index with item==3: array[2]=3
# find_first_index x with x>3: array[3]>3
# find_last_index x with x<=4: array[3]<=4
# exit
# End time: 02:48:51 on Mar 31,2022, Elapsed time: 0:00:01
# Errors: 0, Warnings: 0
Done

（2）排序 orderig

在写这段代码的时候发现了一个有意思的细节，SV内置的数组排序函数都是空函数（void function），因此没有返回值，就不能像上面一样在操作过后把它赋值给一个队列，这里只需要直接调用函数（.sort, .rsort, .reverse, .shuffle），然后打印数组即可！

 

查看代码

module array_ordering;
  int array[8]='{1,2,3,4,5,6,7,8};
  initial begin
	array.sort;
    $display("sort: %p",array);
    array.rsort;
    
    $display("rsort: %p",array);
    array.reverse;
   
    $display("reverse: %p",array);
    
	array.shuffle;
    $display("shuffle: %p",array);  
  end
endmodule

编译结果

# Loading sv_std.std
# Loading work.array_ordering(fast)
# 
# vsim -voptargs=+acc=npr
# run -all
# sort: '{1, 2, 3, 4, 5, 6, 7, 8}
# rsort: '{8, 7, 6, 5, 4, 3, 2, 1}
# reverse: '{1, 2, 3, 4, 5, 6, 7, 8}
# shuffle: '{2, 8, 4, 3, 7, 1, 5, 6}
# exit
# End time: 03:01:14 on Mar 31,2022, Elapsed time: 0:00:01
# Errors: 0, Warnings: 0
Done

（3）缩位

缩位操作（sum, product, and, or, xor）是有返回值的，因此可以赋值给另一个int型变量

 

查看代码

module array_reduction;
  int array[8]='{1,2,3,4,5,6,7,8};
  int res;
  initial begin
    res= array.sum;
    $display("sum: %0d",res);
    res= array.product;
    $display("product: %0d",res);
    res= array.and;
    $display("and: 0x%0h",res);
    res= array.or;
    $display("or: 0x%0h",res);
    res= array.xor;
    $display("and: 0x%0h",res);
  end
endmodule

编译结果

# Loading sv_std.std
# Loading work.array_reduction(fast)
# 
# vsim -voptargs=+acc=npr
# run -all
# sum: 36
# product: 40320
# and: 0x0
# or: 0xf
# and: 0x8
# exit
# End time: 03:15:41 on Mar 31,2022, Elapsed time: 0:00:00
# Errors: 0, Warnings: 0
Done