From: Chris Lattner
; CHECK: test5:
-; CHECK: notw [[REG:%[a-z]+]]
-; CHECK: andw {{.*}}[[REG]]
+; CHECK: notw [[REGISTER:%[a-z]+]]
+; CHECK: andw {{.*}}[[REGISTER]]
The first check line matches a regex (%[a-z]+) and captures it into the -variables "REG". The second line verifies that whatever is in REG occurs later -in the file after an "andw". FileCheck variable references are always contained -in [[ ]] pairs, are named, and their names can be formed with the regex -"[a-zA-Z][a-zA-Z0-9]*". If a colon follows the name, then it is a definition of -the variable, if not, it is a use.
+The first check line matches a regex (%[a-z]+) and captures it into +the variables "REGISTER". The second line verifies that whatever is in REGISTER +occurs later in the file after an "andw". FileCheck variable references are +always contained in [[ ]] pairs, are named, and their names can be +formed with the regex "[a-zA-Z][a-zA-Z0-9]*". If a colon follows the +name, then it is a definition of the variable, if not, it is a use.
FileCheck variables can be defined multiple times, and uses always get the latest value. Note that variables are all read at the start of a "CHECK" line