Specifies the absolute line number (of the current source file) for which the assembler generates subsequent code or data.
.line number
number
Line number of the file; the file's first line is number 1.
By default, the assembler generates all the necessary source line information for debugging purposes. If you want to exercise line-by-line control over the source line information, you can use the .line directive. If there is at least one .line directive in your code, the assembler generates source line information only for the code located immediately after the directive. All other source line information will be suppressed.