Understanding coldfusion code

Understanding coldfusion code

There is a variable being set as follows (through custom tag invocation)
<cfset str = Trim( THISTAG.GeneratedContent ) />
The contents of THISTAG.GeneratedContent looks like
FNAME|MNAME|LNAME Test|Test|Test
The code I am having trouble understanding is as follows:
<cfset str = str.ReplaceAll(
"(?m)^[\t ]+|[\t ]+$",
""
) />
<cfset arrRows = str.Split( "[\r\n]+" ) />
The above line of code should generate array with contents as
arrRows[1] = FNAME|MNAME|LNAME
arrRows[2] = Test|Test|Test
But on dumping the array shows following output:
FNAME|MNAME|LNAME Test|Test|Test
I do not understand what both regular expressions are trying to achieve.