diff -up qt-x11-opensource-src-4.5.3/src/3rdparty/webkit/JavaScriptCore/JavaScriptCore.pri.javascriptcore-disable-jit qt-x11-opensource-src-4.5.3/src/3rdparty/webkit/JavaScriptCore/JavaScriptCore.pri
--- qt-x11-opensource-src-4.5.3/src/3rdparty/webkit/JavaScriptCore/JavaScriptCore.pri.javascriptcore-disable-jit	2009-09-29 13:01:35.000000000 +0200
+++ qt-x11-opensource-src-4.5.3/src/3rdparty/webkit/JavaScriptCore/JavaScriptCore.pri	2009-10-06 10:39:55.976466622 +0200
@@ -13,20 +13,6 @@ win32-* {
     LIBS += -lwinmm
 }
 
-# Disable the JIT due to numerous observed miscompilations :(
-CONFIG(release):isEqual(QT_ARCH,i386) {
-     JIT_DEFINES = ENABLE_JIT ENABLE_WREC ENABLE_JIT_OPTIMIZE_CALL ENABLE_JIT_OPTIMIZE_PROPERTY_ACCESS ENABLE_JIT_OPTIMIZE_ARITHMETIC
-     # Require gcc >= 4.1
-     linux-g++*:greaterThan(QT_GCC_MAJOR_VERSION,3):greaterThan(QT_GCC_MINOR_VERSION,0) {
-         DEFINES += $$JIT_DEFINES WTF_USE_JIT_STUB_ARGUMENT_VA_LIST
-         QMAKE_CXXFLAGS += -fno-stack-protector
-         QMAKE_CFLAGS += -fno-stack-protector
-     }
-     win32-msvc* {
-         DEFINES += $$JIT_DEFINES WTF_USE_JIT_STUB_ARGUMENT_REGISTER
-     }
-}
-
 win32-msvc*: INCLUDEPATH += $$PWD/os-win32
 wince* {
     INCLUDEPATH += $$PWD/os-wince