Implement IEEE-754R 2008 nextUp/nextDown functions in the guise of the function APFlo...

[oota-llvm.git] / include / llvm / ADT / StringExtras.h

diff --git a/include/llvm/ADT/StringExtras.h b/include/llvm/ADT/StringExtras.h
index bf27c4313f82eb6a74400e8b2df0d754c6cdf7e7..d2887c5c2c56f9a18363845983c4bbec517bbedb 100644 (file)
--- a/include/llvm/ADT/StringExtras.h
+++ b/include/llvm/ADT/StringExtras.h
@@ -14,8 +14,8 @@
 #ifndef LLVM_ADT_STRINGEXTRAS_H
 #define LLVM_ADT_STRINGEXTRAS_H
 
-#include "llvm/Support/DataTypes.h"
 #include "llvm/ADT/StringRef.h"
+#include "llvm/Support/DataTypes.h"
 
 namespace llvm {
 template<typename T> class SmallVectorImpl;
@@ -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):