From 8a53a8329f47f86757af17dbea2864aa95414615 Mon Sep 17 00:00:00 2001
From: Jordan Rose <jordan_rose@apple.com>
Date: Fri, 18 Jan 2013 21:45:30 +0000
Subject: [PATCH] Add llvm::hexDigitValue to convert single characters to hex.

This is duplicated in a couple places in the codebase. Adopt this in APFloat.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172851 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/ADT/StringExtras.h | 11 +++++++++++
 lib/Support/APFloat.cpp         | 21 +--------------------
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/include/llvm/ADT/StringExtras.h b/include/llvm/ADT/StringExtras.h
index 9503e0f805a..d2887c5c2c5 100644
--- a/include/llvm/ADT/StringExtras.h
+++ b/include/llvm/ADT/StringExtras.h
@@ -27,6 +27,17 @@ static inline char hexdigit(unsigned X, bool LowerCase = false) {
   return X < 10 ? '0' + X : HexChar + X - 10;
 }
 
+/// Interpret the given character \p C as a hexadecimal digit and return its
+/// value.
+///
+/// If \p C is not a valid hex digit, -1U is returned.
+static inline unsigned hexDigitValue(char C) {
+  if (C >= '0' && C <= '9') return C-'0';
+  if (C >= 'a' && C <= 'f') return C-'a'+10U;
+  if (C >= 'A' && C <= 'F') return C-'A'+10U;
+  return -1U;
+}
+
 /// utohex_buffer - Emit the specified number into the buffer specified by
 /// BufferEnd, returning a pointer to the start of the string.  This can be used
 /// like this: (note that the buffer must be large enough to handle any number):
diff --git a/lib/Support/APFloat.cpp b/lib/Support/APFloat.cpp
index 4a7a5d1a056..2ac86a289a4 100644
--- a/lib/Support/APFloat.cpp
+++ b/lib/Support/APFloat.cpp
@@ -16,6 +16,7 @@
 #include "llvm/ADT/APSInt.h"
 #include "llvm/ADT/FoldingSet.h"
 #include "llvm/ADT/Hashing.h"
+#include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/MathExtras.h"
@@ -101,26 +102,6 @@ decDigitValue(unsigned int c)
   return c - '0';
 }
 
-static unsigned int
-hexDigitValue(unsigned int c)
-{
-  unsigned int r;
-
-  r = c - '0';
-  if (r <= 9)
-    return r;
-
-  r = c - 'A';
-  if (r <= 5)
-    return r + 10;
-
-  r = c - 'a';
-  if (r <= 5)
-    return r + 10;
-
-  return -1U;
-}
-
 /* Return the value of a decimal exponent of the form
    [+-]ddddddd.