From: James Ko <jamesqko@gmail.com>
Date: Wed, 20 Jul 2016 00:18:06 +0000 (-0400)
Subject: Remove duplicate code from string.GetHashCode (#4696)
X-Git-Tag: accepted/tizen/base/20180629.140029~4020
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=1ff9f6b76f1d9c91ce7169689f07d3e61836e7d5;p=platform%2Fupstream%2Fcoreclr.git

Remove duplicate code from string.GetHashCode (#4696)
---

diff --git a/src/mscorlib/src/System/String.cs b/src/mscorlib/src/System/String.cs
index bd5d503..9255c9b 100644
--- a/src/mscorlib/src/System/String.cs
+++ b/src/mscorlib/src/System/String.cs
@@ -880,64 +880,16 @@ namespace System {
         // they will return the same hash code.
         [System.Security.SecuritySafeCritical]  // auto-generated
         [ReliabilityContract(Consistency.WillNotCorruptState, Cer.MayFail)]
-        public override int GetHashCode() {
-
+        public override int GetHashCode()
+        {
 #if FEATURE_RANDOMIZED_STRING_HASHING
-            if(HashHelpers.s_UseRandomizedStringHashing)
+            if (HashHelpers.s_UseRandomizedStringHashing)
             {
                 return InternalMarvin32HashString(this, this.Length, 0);
             }
 #endif // FEATURE_RANDOMIZED_STRING_HASHING
 
-            unsafe {
-                fixed (char* src = &m_firstChar) {
-                    Contract.Assert(src[this.Length] == '\0', "src[this.Length] == '\\0'");
-                    Contract.Assert( ((int)src)%4 == 0, "Managed string should start at 4 bytes boundary");
-
-#if BIT64
-                    int hash1 = 5381;
-#else // !BIT64 (32)
-                    int hash1 = (5381<<16) + 5381;
-#endif
-                    int hash2 = hash1;
-#if BIT64
-                    int     c;
-                    char *s = src;
-                    while ((c = s[0]) != 0) {
-                        hash1 = ((hash1 << 5) + hash1) ^ c;
-                        c = s[1];
-                        if (c == 0)
-                            break;
-                        hash2 = ((hash2 << 5) + hash2) ^ c;
-                        s += 2;
-                    }
-#else // !BIT64 (32)
-                    // 32 bit machines.
-                    int* pint = (int *)src;
-                    int len = this.Length;
-                    while (len > 2)
-                    {
-                        hash1 = ((hash1 << 5) + hash1 + (hash1 >> 27)) ^ pint[0];
-                        hash2 = ((hash2 << 5) + hash2 + (hash2 >> 27)) ^ pint[1];
-                        pint += 2;
-                        len  -= 4;
-                    }
-
-                    if (len > 0)
-                    {
-                        hash1 = ((hash1 << 5) + hash1 + (hash1 >> 27)) ^ pint[0];
-                    }
-#endif
-#if DEBUG
-                    // We want to ensure we can change our hash function daily.
-                    // This is perfectly fine as long as you don't persist the
-                    // value from GetHashCode to disk or count on String A 
-                    // hashing before string B.  Those are bugs in your code.
-                    hash1 ^= ThisAssembly.DailyBuildNumber;
-#endif
-                    return hash1 + (hash2 * 1566083941);
-                }
-            }
+            return GetLegacyNonRandomizedHashCode();
         }
 
         // Use this if and only if you need the hashcode to not change across app domains (e.g. you have an app domain agile