diff --git a/llvm/utils/UpdateTestChecks/common.py b/llvm/utils/UpdateTestChecks/common.py
index b95dd69..f6b22c1 100644
--- a/llvm/utils/UpdateTestChecks/common.py
+++ b/llvm/utils/UpdateTestChecks/common.py
@@ -1,22 +1,16 @@
 from __future__ import print_function
 import re
+import string
 import subprocess
 import sys
 
-RUN_LINE_RE = re.compile('^\s*;\s*RUN:\s*(.*)$')
-CHECK_PREFIX_RE = re.compile('--?check-prefix(?:es)?=(\S+)')
-CHECK_RE = re.compile(r'^\s*;\s*([^:]+?)(?:-NEXT|-NOT|-DAG|-LABEL)?:')
+if sys.version_info[0] > 2:
+  class string:
+    expandtabs = str.expandtabs
+else:
+  import string
 
-IR_FUNCTION_RE = re.compile('^\s*define\s+(?:internal\s+)?[^@]*@(\w+)\s*\(')
-TRIPLE_IR_RE = re.compile(r'^target\s+triple\s*=\s*"([^"]+)"$')
-TRIPLE_ARG_RE = re.compile(r'-mtriple=([^ ]+)')
-
-SCRUB_LEADING_WHITESPACE_RE = re.compile(r'^(\s+)')
-SCRUB_WHITESPACE_RE = re.compile(r'(?!^(|  \w))[ \t]+', flags=re.M)
-SCRUB_TRAILING_WHITESPACE_RE = re.compile(r'[ \t]+$', flags=re.M)
-SCRUB_KILL_COMMENT_RE = re.compile(r'^ *#+ +kill:.*\n')
-SCRUB_LOOP_COMMENT_RE = re.compile(
-    r'# =>This Inner Loop Header:.*|# in Loop:.*', flags=re.M)
+##### Common utilities for update_*test_checks.py
 
 def should_add_line_to_output(input_line, prefix_set):
   # Skip any blank comment lines in the IR.
@@ -42,6 +36,38 @@
   # Fix line endings to unix CR style.
   return stdout.replace('\r\n', '\n')
 
+##### LLVM IR parser
+
+RUN_LINE_RE = re.compile('^\s*;\s*RUN:\s*(.*)$')
+CHECK_PREFIX_RE = re.compile('--?check-prefix(?:es)?=(\S+)')
+CHECK_RE = re.compile(r'^\s*;\s*([^:]+?)(?:-NEXT|-NOT|-DAG|-LABEL)?:')
+
+OPT_FUNCTION_RE = re.compile(
+    r'^\s*define\s+(?:internal\s+)?[^@]*@(?P<func>[\w-]+?)\s*\('
+    r'(\s+)?[^)]*[^{]*\{\n(?P<body>.*?)^\}$',
+    flags=(re.M | re.S))
+
+IR_FUNCTION_RE = re.compile('^\s*define\s+(?:internal\s+)?[^@]*@(\w+)\s*\(')
+TRIPLE_IR_RE = re.compile(r'^target\s+triple\s*=\s*"([^"]+)"$')
+TRIPLE_ARG_RE = re.compile(r'-mtriple=([^ ]+)')
+
+SCRUB_LEADING_WHITESPACE_RE = re.compile(r'^(\s+)')
+SCRUB_WHITESPACE_RE = re.compile(r'(?!^(|  \w))[ \t]+', flags=re.M)
+SCRUB_TRAILING_WHITESPACE_RE = re.compile(r'[ \t]+$', flags=re.M)
+SCRUB_KILL_COMMENT_RE = re.compile(r'^ *#+ +kill:.*\n')
+SCRUB_LOOP_COMMENT_RE = re.compile(
+    r'# =>This Inner Loop Header:.*|# in Loop:.*', flags=re.M)
+
+def scrub_body(body):
+  # Scrub runs of whitespace out of the assembly, but leave the leading
+  # whitespace in place.
+  body = SCRUB_WHITESPACE_RE.sub(r' ', body)
+  # Expand the tabs used for indentation.
+  body = string.expandtabs(body, 2)
+  # Strip trailing whitespace.
+  body = SCRUB_TRAILING_WHITESPACE_RE.sub(r'', body)
+  return body
+
 # Build up a dictionary of all the function bodies.
 def build_function_body_dictionary(function_re, scrubber, scrubber_args, raw_tool_output, prefixes, func_dict, verbose):
   for m in function_re.finditer(raw_tool_output):
@@ -66,3 +92,114 @@
           continue
 
       func_dict[prefix][func] = scrubbed_body
+
+##### Generator of LLVM IR CHECK lines
+
+SCRUB_IR_COMMENT_RE = re.compile(r'\s*;.*')
+
+# Match things that look at identifiers, but only if they are followed by
+# spaces, commas, paren, or end of the string
+IR_VALUE_RE = re.compile(r'(\s+)%([\w\.]+?)([,\s\(\)]|\Z)')
+
+# Create a FileCheck variable name based on an IR name.
+def get_value_name(var):
+  if var.isdigit():
+    var = 'TMP' + var
+  var = var.replace('.', '_')
+  return var.upper()
+
+
+# Create a FileCheck variable from regex.
+def get_value_definition(var):
+  return '[[' + get_value_name(var) + ':%.*]]'
+
+
+# Use a FileCheck variable.
+def get_value_use(var):
+  return '[[' + get_value_name(var) + ']]'
+
+# Replace IR value defs and uses with FileCheck variables.
+def genericize_check_lines(lines):
+  # This gets called for each match that occurs in
+  # a line. We transform variables we haven't seen
+  # into defs, and variables we have seen into uses.
+  def transform_line_vars(match):
+    var = match.group(2)
+    if var in vars_seen:
+      rv = get_value_use(var)
+    else:
+      vars_seen.add(var)
+      rv = get_value_definition(var)
+    # re.sub replaces the entire regex match
+    # with whatever you return, so we have
+    # to make sure to hand it back everything
+    # including the commas and spaces.
+    return match.group(1) + rv + match.group(3)
+
+  vars_seen = set()
+  lines_with_def = []
+
+  for i, line in enumerate(lines):
+    # An IR variable named '%.' matches the FileCheck regex string.
+    line = line.replace('%.', '%dot')
+    # Ignore any comments, since the check lines will too.
+    scrubbed_line = SCRUB_IR_COMMENT_RE.sub(r'', line)
+    lines[i] =  IR_VALUE_RE.sub(transform_line_vars, scrubbed_line)
+  return lines
+
+
+def add_ir_checks(output_lines, prefix_list, func_dict, func_name, opt_basename):
+  # Label format is based on IR string.
+  check_label_format = "; %s-LABEL: @%s("
+
+  printed_prefixes = []
+  for checkprefixes, _ in prefix_list:
+    for checkprefix in checkprefixes:
+      if checkprefix in printed_prefixes:
+        break
+      if not func_dict[checkprefix][func_name]:
+        continue
+      # Add some space between different check prefixes, but not after the last
+      # check line (before the test code).
+      #if len(printed_prefixes) != 0:
+      #  output_lines.append(';')
+      printed_prefixes.append(checkprefix)
+      output_lines.append(check_label_format % (checkprefix, func_name))
+      func_body = func_dict[checkprefix][func_name].splitlines()
+
+      # For IR output, change all defs to FileCheck variables, so we're immune
+      # to variable naming fashions.
+      func_body = genericize_check_lines(func_body)
+
+      # This could be selectively enabled with an optional invocation argument.
+      # Disabled for now: better to check everything. Be safe rather than sorry.
+
+      # Handle the first line of the function body as a special case because
+      # it's often just noise (a useless asm comment or entry label).
+      #if func_body[0].startswith("#") or func_body[0].startswith("entry:"):
+      #  is_blank_line = True
+      #else:
+      #  output_lines.append('; %s:       %s' % (checkprefix, func_body[0]))
+      #  is_blank_line = False
+
+      is_blank_line = False
+
+      for func_line in func_body:
+        if func_line.strip() == '':
+          is_blank_line = True
+          continue
+        # Do not waste time checking IR comments.
+        func_line = SCRUB_IR_COMMENT_RE.sub(r'', func_line)
+
+        # Skip blank lines instead of checking them.
+        if is_blank_line == True:
+          output_lines.append('; %s:       %s' % (checkprefix, func_line))
+        else:
+          output_lines.append('; %s-NEXT:  %s' % (checkprefix, func_line))
+        is_blank_line = False
+
+      # Add space between different check prefixes and also before the first
+      # line of code in the test function.
+      output_lines.append(';')
+      break
+  return output_lines