From f996831427009c5abe37f0af9d9632ef60f181e2 Mon Sep 17 00:00:00 2001
From: Nick Lewycky <nicholas@mxc.ca>
Date: Sat, 7 Feb 2009 04:57:08 +0000
Subject: [PATCH] Add an API for strings with possible NULLs in the middle.
 Refactor the other two AddString methods to use it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64005 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/ADT/FoldingSet.h |  1 +
 lib/Support/FoldingSet.cpp    | 45 +++++++----------------------------
 2 files changed, 9 insertions(+), 37 deletions(-)

diff --git a/include/llvm/ADT/FoldingSet.h b/include/llvm/ADT/FoldingSet.h
index d6010adfb9f..e07c0a0cea1 100644
--- a/include/llvm/ADT/FoldingSet.h
+++ b/include/llvm/ADT/FoldingSet.h
@@ -225,6 +225,7 @@ public:
   void AddInteger(unsigned long I);
   void AddInteger(long long I);
   void AddInteger(unsigned long long I);
+  void AddString(const char* String, const char* End);
   void AddString(const std::string &String);
   void AddString(const char* String);
 
diff --git a/lib/Support/FoldingSet.cpp b/lib/Support/FoldingSet.cpp
index 3a1a0cd842e..41c730e3e1e 100644
--- a/lib/Support/FoldingSet.cpp
+++ b/lib/Support/FoldingSet.cpp
@@ -62,8 +62,8 @@ void FoldingSetNodeID::AddInteger(unsigned long long I) {
     Bits.push_back(unsigned(I >> 32));
 }
 
-void FoldingSetNodeID::AddString(const char *String) {
-  unsigned Size = static_cast<unsigned>(strlen(String));
+void FoldingSetNodeID::AddString(const char *String, const char *End) {
+  unsigned Size =  static_cast<unsigned>(End - String);
   Bits.push_back(Size);
   if (!Size) return;
 
@@ -77,7 +77,7 @@ void FoldingSetNodeID::AddString(const char *String) {
     Pos = (Units + 1) * 4;
   } else {
     // Otherwise do it the hard way.
-    for ( Pos += 4; Pos <= Size; Pos += 4) {
+    for (Pos += 4; Pos <= Size; Pos += 4) {
       unsigned V = ((unsigned char)String[Pos - 4] << 24) |
                    ((unsigned char)String[Pos - 3] << 16) |
                    ((unsigned char)String[Pos - 2] << 8) |
@@ -99,41 +99,12 @@ void FoldingSetNodeID::AddString(const char *String) {
   Bits.push_back(V);
 }
 
-void FoldingSetNodeID::AddString(const std::string &String) {
-  unsigned Size = static_cast<unsigned>(String.size());
-  Bits.push_back(Size);
-  if (!Size) return;
-
-  unsigned Units = Size / 4;
-  unsigned Pos = 0;
-  const unsigned *Base = (const unsigned *)String.data();
-  
-  // If the string is aligned do a bulk transfer.
-  if (!((intptr_t)Base & 3)) {
-    Bits.append(Base, Base + Units);
-    Pos = (Units + 1) * 4;
-  } else {
-    // Otherwise do it the hard way.
-    for ( Pos += 4; Pos <= Size; Pos += 4) {
-      unsigned V = ((unsigned char)String[Pos - 4] << 24) |
-                   ((unsigned char)String[Pos - 3] << 16) |
-                   ((unsigned char)String[Pos - 2] << 8) |
-                    (unsigned char)String[Pos - 1];
-      Bits.push_back(V);
-    }
-  }
-  
-  // With the leftover bits.
-  unsigned V = 0;
-  // Pos will have overshot size by 4 - #bytes left over. 
-  switch (Pos - Size) {
-  case 1: V = (V << 8) | (unsigned char)String[Size - 3]; // Fall thru.
-  case 2: V = (V << 8) | (unsigned char)String[Size - 2]; // Fall thru.
-  case 3: V = (V << 8) | (unsigned char)String[Size - 1]; break;
-  default: return; // Nothing left.
-  }
+void FoldingSetNodeID::AddString(const char *String) {
+  AddString(String, String + strlen(String));
+}
 
-  Bits.push_back(V);
+void FoldingSetNodeID::AddString(const std::string &String) {
+  AddString(&*String.begin(), &*String.end());
 }
 
 /// ComputeHash - Compute a strong hash value for this FoldingSetNodeID, used to 
-- 
2.34.1