From e54ad9ee866309d870a8f947b7d612d62b753069 Mon Sep 17 00:00:00 2001
From: "serya@chromium.org"
 <serya@chromium.org@ce2b1a6d-e550-0410-aec6-3dcde31c8c00>
Date: Tue, 7 Sep 2010 11:32:20 +0000
Subject: [PATCH] Removing a wrong check.

A strings which represents an array index with length 8 and 9 digits do not pass this check. However generated hash is valid.

Review URL: http://codereview.chromium.org/3295017

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5420 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
---
 src/objects.cc             | 13 ++++++++-----
 src/objects.h              |  3 ++-
 src/runtime.cc             |  3 +--
 test/mjsunit/str-to-num.js |  4 ++++
 4 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/src/objects.cc b/src/objects.cc
index 6a46c26..ef51851 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -4988,17 +4988,20 @@ bool String::SlowAsArrayIndex(uint32_t* index) {
 }
 
 
-uint32_t StringHasher::MakeCachedArrayIndex(uint32_t value, int length) {
-  value <<= String::kHashShift;
+uint32_t StringHasher::MakeArrayIndexHash(uint32_t value, int length) {
   // For array indexes mix the length into the hash as an array index could
   // be zero.
   ASSERT(length > 0);
   ASSERT(length <= String::kMaxArrayIndexSize);
   ASSERT(TenToThe(String::kMaxCachedArrayIndexLength) <
          (1 << String::kArrayIndexValueBits));
-  ASSERT(String::kMaxArrayIndexSize < (1 << String::kArrayIndexValueBits));
-  value &= ~String::kIsNotArrayIndexMask;
+
+  value <<= String::kHashShift;
   value |= length << String::kArrayIndexHashLengthShift;
+
+  ASSERT((value & String::kIsNotArrayIndexMask) == 0);
+  ASSERT((length > String::kMaxCachedArrayIndexLength) ||
+         (value & String::kContainsCachedArrayIndexMask) == 0);
   return value;
 }
 
@@ -5007,7 +5010,7 @@ uint32_t StringHasher::GetHashField() {
   ASSERT(is_valid());
   if (length_ <= String::kMaxHashCalcLength) {
     if (is_array_index()) {
-      return MakeCachedArrayIndex(array_index(), length_);
+      return MakeArrayIndexHash(array_index(), length_);
     }
     return (GetHash() << String::kHashShift) | String::kIsNotArrayIndexMask;
   } else {
diff --git a/src/objects.h b/src/objects.h
index ca668b4..7f6538c 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -4223,7 +4223,7 @@ class StringHasher {
   // Calculated hash value for a string consisting of 1 to
   // String::kMaxArrayIndexSize digits with no leading zeros (except "0").
   // value is represented decimal value.
-  static uint32_t MakeCachedArrayIndex(uint32_t value, int length);
+  static uint32_t MakeArrayIndexHash(uint32_t value, int length);
 
  private:
 
@@ -4467,6 +4467,7 @@ class String: public HeapObject {
       kBitsPerInt - kArrayIndexValueBits - kNofHashBitFields;
 
   STATIC_CHECK((kArrayIndexLengthBits > 0));
+  STATIC_CHECK(kMaxArrayIndexSize < (1 << kArrayIndexLengthBits));
 
   static const int kArrayIndexHashLengthShift =
       kArrayIndexValueBits + kNofHashBitFields;
diff --git a/src/runtime.cc b/src/runtime.cc
index c7ec6bf..43a6734 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -4677,9 +4677,8 @@ static Object* Runtime_StringToNumber(Arguments args) {
                  (len == 1 || data[0] != '0')) {
         // String hash is not calculated yet but all the data are present.
         // Update the hash field to speed up sequential convertions.
-        uint32_t hash = StringHasher::MakeCachedArrayIndex(d, len);
+        uint32_t hash = StringHasher::MakeArrayIndexHash(d, len);
 #ifdef DEBUG
-        ASSERT((hash & String::kContainsCachedArrayIndexMask) == 0);
         subject->Hash();  // Force hash calculation.
         ASSERT_EQ(static_cast<int>(subject->hash_field()),
                   static_cast<int>(hash));
diff --git a/test/mjsunit/str-to-num.js b/test/mjsunit/str-to-num.js
index 20e2986..28e98d9 100644
--- a/test/mjsunit/str-to-num.js
+++ b/test/mjsunit/str-to-num.js
@@ -203,3 +203,7 @@ assertTrue(isNaN(toNumber("Infinity junk")), "Infinity junk");
 assertTrue(isNaN(toNumber("1e")), "1e");
 assertTrue(isNaN(toNumber("1e ")), "1e_");
 assertTrue(isNaN(toNumber("1" + repeat('0', 1000) + 'junk')), "1e1000 junk");
+
+for (var i = 1; i < 12; i++) {
+  assertEquals(toNumber('1' + repeat('0', i)), Math.pow(10.0, i));
+}
-- 
2.7.4