Changeset 167382 in webkit

Timestamp:

Apr 16, 2014 1:54:43 PM (10 years ago)

Author:

commit-queue@webkit.org

Message:

Fix JSC Debug Regressions on Windows
​https://bugs.webkit.org/show_bug.cgi?id=131182

Patch by ​peavo@outlook.com <​peavo@outlook.com> on 2014-04-16
Reviewed by Brent Fulgham.

The cast static_cast<int64_t>(number) in JSValue::isMachineInt() can generate a floating point error,
and set the st floating point register tags, if the value of the number parameter is infinite.
If the st floating point register tags are not cleared, this can cause strange floating point behavior later on.
This can be avoided by checking for infinity first.

• runtime/JSCJSValueInlines.h:

(JSC::JSValue::isMachineInt): Avoid floating point error by checking for infinity first.

• runtime/Options.cpp:

(JSC::recomputeDependentOptions): Re-enable jit for Windows.

Location:

trunk/Source/JavaScriptCore

Files:

• ChangeLog (modified) (1 diff)
• runtime/JSCJSValueInlines.h (modified) (1 diff)
• runtime/Options.cpp (modified) (1 diff)

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2014-04-16  peavo@outlook.com  <peavo@outlook.com>
+
+        Fix JSC Debug Regressions on Windows
+        https://bugs.webkit.org/show_bug.cgi?id=131182
+
+        Reviewed by Brent Fulgham.
+
+        The cast static_cast<int64_t>(number) in JSValue::isMachineInt() can generate a floating point error,
+        and set the st floating point register tags, if the value of the number parameter is infinite.
+        If the st floating point register tags are not cleared, this can cause strange floating point behavior later on.
+        This can be avoided by checking for infinity first.
+
+        * runtime/JSCJSValueInlines.h:
+        (JSC::JSValue::isMachineInt): Avoid floating point error by checking for infinity first.
+        * runtime/Options.cpp:
+        (JSC::recomputeDependentOptions): Re-enable jit for Windows.
+
 2014-04-16  Oliver Hunt  <oliver@apple.com>
 

trunk/Source/JavaScriptCore/runtime/JSCJSValueInlines.h

@@ -505 +505 @@
     if (number != number)
         return false;
+#if OS(WINDOWS)
+    // Need to check for infinity on Windows to avoid floating point error on following cast, see bug 131182.
+    if (std::isinf(number))
+        return false;
+#endif
     int64_t asInt64 = static_cast<int64_t>(number);
     if (asInt64 != number)

trunk/Source/JavaScriptCore/runtime/Options.cpp

@@ -226 +226 @@
 #if !ENABLE(FTL_JIT)
     Options::useFTLJIT() = false;
-#endif
-#if OS(WINDOWS)
-    // Temporarily disable the JIT on Windows until we have a fix for
-    // https://webkit.org/b/131182.
-    Options::useJIT() = false;
 #endif