Index: docs/CommandGuide/FileCheck.rst
===================================================================
--- docs/CommandGuide/FileCheck.rst
+++ docs/CommandGuide/FileCheck.rst
@@ -81,6 +81,11 @@
 
  Show the version number of this program.
 
+.. option:: --check-word
+
+  Adds condition for successful matching:string described in check-line should be 
+  a separate word, but not a part of another word.
+
 EXIT STATUS
 -----------
 
@@ -169,6 +174,24 @@
 In this case, we're testing that we get the expected code generation with
 both 32-bit and 64-bit code generation.
 
+The FileCheck -check-word option
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+If you want find some strings in file, but you want to be sure, that these 
+strings should be separate words, but not a part of other words you should 
+use :option:`-check-word` option.
+
+For example
+
+.. code-block:: llvm
+
+    // RUN: FileCheck -input-file %s %s -check-word
+
+    reg
+    // CHECK-WORD: {{[a-z]+}}
+
+This check will match with reg, but not with reg12.
+
 The "CHECK-NEXT:" directive
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
Index: test/FileCheck/check-word.txt
===================================================================
--- /dev/null
+++ test/FileCheck/check-word.txt
@@ -0,0 +1,32 @@
+// RUN: FileCheck -input-file %s %s -check-word
+// RUN: not FileCheck -input-file %s %s -check-prefix=FAILTEST -check-word
+
+first
+and
+// FAILTEST: first
+// FAILTEST-SAME: and
+
+op1;
+op2;
+op33;
+// CHECK: op{{[0-9]}};
+// CHECK-NEXT: op{{[0-9]}};
+// CHECK-NOT: op{{[0-9]}}
+
+first and
+// CHECK: first
+// CHECK-SAME: and
+This is second line
+// CHECK: second
+
+one two three
+// CHECK-DAG: two
+// CHECK-DAG: three
+// CHECK-DAG: one
+
+four!
+// CHECK: four
+dog
+line
+// CHECK-NOT: cat
+// CHECK: line
Index: utils/FileCheck/FileCheck.cpp
===================================================================
--- utils/FileCheck/FileCheck.cpp
+++ utils/FileCheck/FileCheck.cpp
@@ -73,6 +73,12 @@
              "Allows leading and trailing whitespace if --strict-whitespace\n"
              "is not also passed."));
 
+static cl::opt<bool> CheckWordMode(
+    "check-word", cl::init(false),
+    cl::desc("Adds condition for successful matching:\n"
+             "string described in check-line should be a separate word,\n"
+             "but not a part of another word."));
+
 typedef cl::list<std::string>::const_iterator prefix_iterator;
 
 //===----------------------------------------------------------------------===//
@@ -654,6 +660,9 @@
   size_t CheckDag(const SourceMgr &SM, StringRef Buffer,
                   std::vector<const Pattern *> &NotStrings,
                   StringMap<StringRef> &VariableTable) const;
+
+  /// CheckWord - Verify there is a single word.
+  bool CheckWord(const size_t &MatchPos, const size_t MatchLen, StringRef Buffer) const;
 };
 
 /// Canonicalize whitespaces in the input file. Line endings are replaced
@@ -1090,6 +1099,10 @@
   if (!IsLabelScanMode) {
     StringRef SkippedRegion = Buffer.substr(LastPos, MatchPos);
 
+    // If this check is a "CHECK-WORD", verify the bounds of string.
+    if (CheckWord(LastPos + MatchPos, MatchLen, Buffer))
+      return StringRef::npos;
+
     // If this check is a "CHECK-NEXT", verify that the previous match was on
     // the previous line (i.e. that there is one newline between them).
     if (CheckNext(SM, SkippedRegion))
@@ -1102,13 +1115,34 @@
 
     // If this match had "not strings", verify that they don't exist in the
     // skipped region.
-    if (CheckNot(SM, SkippedRegion, NotStrings, VariableTable))
+    if (CheckNot(SM, SkippedRegion, NotStrings, VariableTable) && !CheckWordMode)
       return StringRef::npos;
   }
 
   return LastPos + MatchPos;
 }
 
+bool CheckString::CheckWord(const size_t &MatchPos, const size_t MatchLen,
+                            StringRef Buffer) const {
+  bool isWord = true;
+  if (!CheckWordMode)
+    return false;
+  // Check previous and next characters to understand word or not.
+  if (MatchPos != 0) {
+    if (!isspace(Buffer[MatchPos - 1]) && !ispunct(Buffer[MatchPos - 1])) {
+      isWord = false;
+    }
+  }
+  if (MatchPos + MatchLen < Buffer.size() &&
+      !isspace(Buffer[MatchPos + MatchLen]) &&
+      !ispunct(Buffer[MatchPos + MatchLen])) {
+    isWord = false;
+  }
+
+  return (Pat.getCheckTy() == Check::CheckNot && isWord) ||
+         (Pat.getCheckTy() != Check::CheckNot && !isWord);
+}
+
 bool CheckString::CheckNext(const SourceMgr &SM, StringRef Buffer) const {
   if (Pat.getCheckTy() != Check::CheckNext)
     return false;