diff --git a/tools/indent_arm_assembly.pl b/tools/indent_arm_assembly.pl
index 359c2bcf4f..aefd58265d 100755
--- a/tools/indent_arm_assembly.pl
+++ b/tools/indent_arm_assembly.pl
@@ -219,10 +219,23 @@ while (<$in>) {
             $operand_space = spaces($size);
         }
 
+        # Lowercase register names. Only apply this on lines up to
+        # comments, as this can match common spec/code references in
+        # code comments. Split the string on // for comments, apply the
+        # substitution on the first segment (up to a comment char), and
+        # join the string again.
+        my @parts = split(/\/\//, $rest);
+        $parts[0] =~ s/\b([XWVQDSHBZP][0-9]+)\b/lc($1)/ge;
+        $rest = join('//', @parts);
+
         # Lowercase the aarch64 vector layout description, .8B -> .8b
         $rest =~ s/(\.[84216]*[BHSD])/lc($1)/ge;
         # Lowercase modifiers like "uxtw" or "lsl"
         $rest =~ s/([SU]XT[BWH]|[LA]S[LR])/lc($1)/ge;
+        # Lowercase SVE/SME modifiers like "/Z" or "/M"
+        $rest =~ s,(/[ZM])\b,lc($1),ge;
+        # Lowercase SVE/SME vector lengths
+        $rest =~ s/\b(VL[0-9]+)\b/lc($1)/ge;
 
         # Reassemble the line
         if ($rest eq "") {