From 9d415787abfbb58911d3d258ccf8e6a2ead8d296 Mon Sep 17 00:00:00 2001
From: Benjamin Kramer <benny.kra@googlemail.com>
Date: Thu, 27 Oct 2011 14:08:01 +0000
Subject: [PATCH] LLLexer: Factor hex char parsing.

llvm-svn: 143101
---
 llvm/lib/AsmParser/LLLexer.cpp | 54 ++++++++++------------------------
 1 file changed, 16 insertions(+), 38 deletions(-)

diff --git a/llvm/lib/AsmParser/LLLexer.cpp b/llvm/lib/AsmParser/LLLexer.cpp
index 91d6c6a26d87..1b6b11a5d3eb 100644
--- a/llvm/lib/AsmParser/LLLexer.cpp
+++ b/llvm/lib/AsmParser/LLLexer.cpp
@@ -55,18 +55,22 @@ uint64_t LLLexer::atoull(const char *Buffer, const char *End) {
   return Result;
 }
 
+static char parseHexChar(char C) {
+  if (C >= '0' && C <= '9')
+    return C-'0';
+  if (C >= 'A' && C <= 'F')
+    return C-'A'+10;
+  if (C >= 'a' && C <= 'f')
+    return C-'a'+10;
+  return 0;
+}
+
 uint64_t LLLexer::HexIntToVal(const char *Buffer, const char *End) {
   uint64_t Result = 0;
   for (; Buffer != End; ++Buffer) {
     uint64_t OldRes = Result;
     Result *= 16;
-    char C = *Buffer;
-    if (C >= '0' && C <= '9')
-      Result += C-'0';
-    else if (C >= 'A' && C <= 'F')
-      Result += C-'A'+10;
-    else if (C >= 'a' && C <= 'f')
-      Result += C-'a'+10;
+    Result += parseHexChar(*Buffer);
 
     if (Result < OldRes) {   // Uh, oh, overflow detected!!!
       Error("constant bigger than 64 bits detected!");
@@ -82,24 +86,12 @@ void LLLexer::HexToIntPair(const char *Buffer, const char *End,
   for (int i=0; i<16; i++, Buffer++) {
     assert(Buffer != End);
     Pair[0] *= 16;
-    char C = *Buffer;
-    if (C >= '0' && C <= '9')
-      Pair[0] += C-'0';
-    else if (C >= 'A' && C <= 'F')
-      Pair[0] += C-'A'+10;
-    else if (C >= 'a' && C <= 'f')
-      Pair[0] += C-'a'+10;
+    Pair[0] += parseHexChar(*Buffer);
   }
   Pair[1] = 0;
   for (int i=0; i<16 && Buffer != End; i++, Buffer++) {
     Pair[1] *= 16;
-    char C = *Buffer;
-    if (C >= '0' && C <= '9')
-      Pair[1] += C-'0';
-    else if (C >= 'A' && C <= 'F')
-      Pair[1] += C-'A'+10;
-    else if (C >= 'a' && C <= 'f')
-      Pair[1] += C-'a'+10;
+    Pair[1] += parseHexChar(*Buffer);
   }
   if (Buffer != End)
     Error("constant bigger than 128 bits detected!");
@@ -113,24 +105,12 @@ void LLLexer::FP80HexToIntPair(const char *Buffer, const char *End,
   for (int i=0; i<4 && Buffer != End; i++, Buffer++) {
     assert(Buffer != End);
     Pair[1] *= 16;
-    char C = *Buffer;
-    if (C >= '0' && C <= '9')
-      Pair[1] += C-'0';
-    else if (C >= 'A' && C <= 'F')
-      Pair[1] += C-'A'+10;
-    else if (C >= 'a' && C <= 'f')
-      Pair[1] += C-'a'+10;
+    Pair[1] += parseHexChar(*Buffer);
   }
   Pair[0] = 0;
   for (int i=0; i<16; i++, Buffer++) {
     Pair[0] *= 16;
-    char C = *Buffer;
-    if (C >= '0' && C <= '9')
-      Pair[0] += C-'0';
-    else if (C >= 'A' && C <= 'F')
-      Pair[0] += C-'A'+10;
-    else if (C >= 'a' && C <= 'f')
-      Pair[0] += C-'a'+10;
+    Pair[0] += parseHexChar(*Buffer);
   }
   if (Buffer != End)
     Error("constant bigger than 128 bits detected!");
@@ -149,9 +129,7 @@ static void UnEscapeLexed(std::string &Str) {
         *BOut++ = '\\'; // Two \ becomes one
         BIn += 2;
       } else if (BIn < EndBuffer-2 && isxdigit(BIn[1]) && isxdigit(BIn[2])) {
-        char Tmp = BIn[3]; BIn[3] = 0;      // Terminate string
-        *BOut = (char)strtol(BIn+1, 0, 16); // Convert to number
-        BIn[3] = Tmp;                       // Restore character
+        *BOut = parseHexChar(BIn[1]) * 16 + parseHexChar(BIn[2]);
         BIn += 3;                           // Skip over handled chars
         ++BOut;
       } else {