Revision: 10338
Author: [email protected]
Date: Thu Jan 5 02:18:28 2012
Log: Fix the logic that should ensure that a string cannot have
a hash key of zero.
Review URL: http://codereview.chromium.org/9113006
http://code.google.com/p/v8/source/detail?r=10338
Modified:
/branches/bleeding_edge/src/objects-inl.h
/branches/bleeding_edge/src/objects.cc
/branches/bleeding_edge/src/objects.h
=======================================
--- /branches/bleeding_edge/src/objects-inl.h Wed Jan 4 07:12:15 2012
+++ /branches/bleeding_edge/src/objects-inl.h Thu Jan 5 02:18:28 2012
@@ -4381,7 +4381,7 @@
result += (result << 3);
result ^= (result >> 11);
result += (result << 15);
- if (result == 0) {
+ if ((result & String::kHashBitMask) == 0) {
result = 27;
}
return result;
=======================================
--- /branches/bleeding_edge/src/objects.cc Wed Jan 4 07:12:15 2012
+++ /branches/bleeding_edge/src/objects.cc Thu Jan 5 02:18:28 2012
@@ -11444,7 +11444,7 @@
hash += hash << 3;
hash ^= hash >> 11;
hash += hash << 15;
- if (hash == 0) hash = 27;
+ if ((hash & String::kHashBitMask) == 0) hash = 27;
#ifdef DEBUG
StringHasher hasher(2, seed);
hasher.AddCharacter(c1);
=======================================
--- /branches/bleeding_edge/src/objects.h Wed Jan 4 09:29:01 2012
+++ /branches/bleeding_edge/src/objects.h Thu Jan 5 02:18:28 2012
@@ -6459,6 +6459,10 @@
// Shift constant retrieving hash code from hash field.
static const int kHashShift = kNofHashBitFields;
+ // Only these bits are relevant in the hash, since the top two are
shifted
+ // out.
+ static const uint32_t kHashBitMask = 0xffffffffu >> kHashShift;
+
// Array index strings this short can keep their index in the hash
// field.
static const int kMaxCachedArrayIndexLength = 7;
--
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