Index: llvm/include/llvm/Support/GlobPattern.h
===================================================================
--- llvm/include/llvm/Support/GlobPattern.h
+++ llvm/include/llvm/Support/GlobPattern.h
@@ -31,6 +31,16 @@
   static Expected<GlobPattern> create(StringRef Pat);
   bool match(StringRef S) const;
 
+  // Returns true for glob pattern "*". Can be used to avoid expensive
+  // preparation/acquisition of the input for match().
+  bool isTrivialMatchAll() const {
+    if (Prefix && Prefix->empty()) {
+      assert(!Suffix);
+      return true;
+    }
+    return false;
+  }
+
 private:
   bool matchOne(ArrayRef<BitVector> Pat, StringRef S) const;
 
Index: llvm/unittests/Support/GlobPatternTest.cpp
===================================================================
--- llvm/unittests/Support/GlobPatternTest.cpp
+++ llvm/unittests/Support/GlobPatternTest.cpp
@@ -133,4 +133,17 @@
   EXPECT_TRUE((bool)Pat2);
   EXPECT_TRUE(Pat2->match("\xFF"));
 }
+
+TEST_F(GlobPatternTest, IsTrivialMatchAll) {
+  Expected<GlobPattern> Pat1 = GlobPattern::create("*");
+  EXPECT_TRUE((bool)Pat1);
+  EXPECT_TRUE(Pat1->isTrivialMatchAll());
+
+  const char *NegativeCases[] = {"a*", "*a", "?*", "*?", "**", "\\*"};
+  for (unsigned i = 0; i < array_lengthof(NegativeCases); ++i) {
+    Expected<GlobPattern> Pat2 = GlobPattern::create(NegativeCases[i]);
+    EXPECT_TRUE((bool)Pat2);
+    EXPECT_FALSE(Pat2->isTrivialMatchAll());
+  }
+}
 }