diff --git a/llvm/include/llvm/ADT/StringRef.h b/llvm/include/llvm/ADT/StringRef.h
--- a/llvm/include/llvm/ADT/StringRef.h
+++ b/llvm/include/llvm/ADT/StringRef.h
@@ -195,9 +195,6 @@
       return Length == RHS.Length && compare_insensitive(RHS) == 0;
     }
 
-    LLVM_NODISCARD
-    bool equals_lower(StringRef RHS) const { return equals_insensitive(RHS); }
-
     /// compare - Compare two strings; the result is -1, 0, or 1 if this string
     /// is lexicographically less than, equal to, or greater than the \p RHS.
     LLVM_NODISCARD
@@ -216,9 +213,6 @@
     LLVM_NODISCARD
     int compare_insensitive(StringRef RHS) const;
 
-    LLVM_NODISCARD
-    int compare_lower(StringRef RHS) const { return compare_insensitive(RHS); }
-
     /// compare_numeric - Compare two strings, treating sequences of digits as
     /// numbers.
     LLVM_NODISCARD
@@ -298,11 +292,6 @@
     LLVM_NODISCARD
     bool startswith_insensitive(StringRef Prefix) const;
 
-    LLVM_NODISCARD
-    bool startswith_lower(StringRef Prefix) const {
-      return startswith_insensitive(Prefix);
-    }
-
     /// Check if this string ends with the given \p Suffix.
     LLVM_NODISCARD
     bool endswith(StringRef Suffix) const {
@@ -314,11 +303,6 @@
     LLVM_NODISCARD
     bool endswith_insensitive(StringRef Suffix) const;
 
-    LLVM_NODISCARD
-    bool endswith_lower(StringRef Prefix) const {
-      return endswith_insensitive(Prefix);
-    }
-
     /// @}
     /// @name String Searching
     /// @{
@@ -345,11 +329,6 @@
     LLVM_NODISCARD
     size_t find_insensitive(char C, size_t From = 0) const;
 
-    LLVM_NODISCARD
-    size_t find_lower(char C, size_t From = 0) const {
-      return find_insensitive(C, From);
-    }
-
     /// Search for the first character satisfying the predicate \p F
     ///
     /// \returns The index of the first character satisfying \p F starting from
@@ -388,11 +367,6 @@
     LLVM_NODISCARD
     size_t find_insensitive(StringRef Str, size_t From = 0) const;
 
-    LLVM_NODISCARD
-    size_t find_lower(StringRef Str, size_t From = 0) const {
-      return find_insensitive(Str, From);
-    }
-
     /// Search for the last character \p C in the string.
     ///
     /// \returns The index of the last occurrence of \p C, or npos if not
@@ -416,11 +390,6 @@
     LLVM_NODISCARD
     size_t rfind_insensitive(char C, size_t From = npos) const;
 
-    LLVM_NODISCARD
-    size_t rfind_lower(char C, size_t From = npos) const {
-      return rfind_insensitive(C, From);
-    }
-
     /// Search for the last string \p Str in the string.
     ///
     /// \returns The index of the last occurrence of \p Str, or npos if not
@@ -435,9 +404,6 @@
     LLVM_NODISCARD
     size_t rfind_insensitive(StringRef Str) const;
 
-    LLVM_NODISCARD
-    size_t rfind_lower(StringRef Str) const { return rfind_insensitive(Str); }
-
     /// Find the first character in the string that is \p C, or npos if not
     /// found. Same as find.
     LLVM_NODISCARD
@@ -507,11 +473,6 @@
       return find_insensitive(Other) != npos;
     }
 
-    LLVM_NODISCARD
-    bool contains_lower(StringRef Other) const {
-      return contains_insensitive(Other);
-    }
-
     /// Return true if the given character is contained in *this, and false
     /// otherwise.
     LLVM_NODISCARD
@@ -519,9 +480,6 @@
       return find_insensitive(C) != npos;
     }
 
-    LLVM_NODISCARD
-    bool contains_lower(char C) const { return contains_insensitive(C); }
-
     /// @}
     /// @name Helpful Algorithms
     /// @{
@@ -739,10 +697,6 @@
       return true;
     }
 
-    bool consume_front_lower(StringRef Prefix) {
-      return consume_front_insensitive(Prefix);
-    }
-
     /// Returns true if this StringRef has the given suffix and removes that
     /// suffix.
     bool consume_back(StringRef Suffix) {
@@ -763,10 +717,6 @@
       return true;
     }
 
-    bool consume_back_lower(StringRef Suffix) {
-      return consume_back_insensitive(Suffix);
-    }
-
     /// Return a reference to the substring from [Start, End).
     ///
     /// \param Start The index of the starting character in the substring; if