Updated JavaScriptCore from /home/khansen/dev/qtwebkit-qtscript-integration to javascriptcore-snapshot-07042010 ( da4f912a2f648d518628e1066dace894d1da7081 )

[Windows] Fix a bug of round() with huge integral numbers
https://bugs.webkit.org/show_bug.cgi?id=34297

3 files changed, 44 insertions, 7 deletions

diff --git a/src/3rdparty/javascriptcore/JavaScriptCore/ChangeLog b/src/3rdparty/javascriptcore/JavaScriptCore/ChangeLog
index 68411ab..cfad1ea 100644
--- a/src/3rdparty/javascriptcore/JavaScriptCore/ChangeLog
+++ b/src/3rdparty/javascriptcore/JavaScriptCore/ChangeLog
@@ -1,3 +1,27 @@
+2010-01-31  Kent Tamura  <tkent@chromium.org>
+
+        Reviewed by Darin Adler.
+
+        [Windows] Fix a bug of round() with huge integral numbers
+        https://bugs.webkit.org/show_bug.cgi?id=34297
+
+        Fix a bug that round() for huge integral numbers returns incorrect
+        results. For example, round(8639999913600001) returns
+        8639999913600002 without this change though the double type can
+        represent 8639999913600001 precisely.
+
+        Math.round() of JavaScript has a similar problem. But this change
+        doesn't fix it because Math.round() doesn't use round() of
+        MathExtra.h.
+
+        * wtf/MathExtras.h:
+        (round): Avoid to do "num + 0.5" or "num - 0.5".
+        (roundf): Fixed similarly.
+        (llround): Calls round().
+        (llroundf): Calls roundf().
+        (lround): Calls round().
+        (lroundf): Calls roundf().
+
 2010-01-27  Anton Muhin  <antonm@chromium.org>
 
         Reviewed by Darin Adler.
diff --git a/src/3rdparty/javascriptcore/JavaScriptCore/wtf/MathExtras.h b/src/3rdparty/javascriptcore/JavaScriptCore/wtf/MathExtras.h
index 9ea57fd..a18949e 100644
--- a/src/3rdparty/javascriptcore/JavaScriptCore/wtf/MathExtras.h
+++ b/src/3rdparty/javascriptcore/JavaScriptCore/wtf/MathExtras.h
@@ -98,12 +98,25 @@ inline bool signbit(double x) { struct ieee_double *p = (struct ieee_double *)&x
 
 #if COMPILER(MSVC) || COMPILER(RVCT)
 
-inline long long llround(double num) { return static_cast<long long>(num > 0 ? num + 0.5 : ceil(num - 0.5)); }
-inline long long llroundf(float num) { return static_cast<long long>(num > 0 ? num + 0.5f : ceil(num - 0.5f)); }
-inline long lround(double num) { return static_cast<long>(num > 0 ? num + 0.5 : ceil(num - 0.5)); }
-inline long lroundf(float num) { return static_cast<long>(num > 0 ? num + 0.5f : ceilf(num - 0.5f)); }
-inline double round(double num) { return num > 0 ? floor(num + 0.5) : ceil(num - 0.5); }
-inline float roundf(float num) { return num > 0 ? floorf(num + 0.5f) : ceilf(num - 0.5f); }
+// We must not do 'num + 0.5' or 'num - 0.5' because they can cause precision loss.
+static double round(double num)
+{
+    double integer = ceil(num);
+    if (num > 0)
+        return integer - num > 0.5 ? integer - 1.0 : integer;
+    return integer - num >= 0.5 ? integer - 1.0 : integer;
+}
+static float roundf(float num)
+{
+    float integer = ceilf(num);
+    if (num > 0)
+        return integer - num > 0.5f ? integer - 1.0f : integer;
+    return integer - num >= 0.5f ? integer - 1.0f : integer;
+}
+inline long long llround(double num) { return static_cast<long long>(round(num)); }
+inline long long llroundf(float num) { return static_cast<long long>(roundf(num)); }
+inline long lround(double num) { return static_cast<long>(round(num)); }
+inline long lroundf(float num) { return static_cast<long>(roundf(num)); }
 inline double trunc(double num) { return num > 0 ? floor(num) : ceil(num); }
 
 #endif
diff --git a/src/3rdparty/javascriptcore/VERSION b/src/3rdparty/javascriptcore/VERSION
index 581837e..a96e22f 100644
--- a/src/3rdparty/javascriptcore/VERSION
+++ b/src/3rdparty/javascriptcore/VERSION
@@ -8,4 +8,4 @@ The commit imported was from the
 
 and has the sha1 checksum
 
-        8662fcc9bb1d374fa10114fe629f18290641cccc
+        da4f912a2f648d518628e1066dace894d1da7081