Source: Debian
--- a/Source/cmake/WebKitCompilerFlags.cmake	2020-12-15 15:29:50.240722972 +0700
+++ b/Source/cmake/WebKitCompilerFlags.cmake	2020-12-15 15:29:59.659853014 +0700
@@ -141,15 +141,6 @@
     if (CMAKE_COMPILER_IS_GNUCXX)
         WEBKIT_PREPEND_GLOBAL_COMPILER_FLAGS(-Wno-expansion-to-defined)
     endif ()
-
-    # Force SSE2 fp on x86 builds.
-    if (WTF_CPU_X86 AND NOT CMAKE_CROSSCOMPILING)
-        WEBKIT_PREPEND_GLOBAL_COMPILER_FLAGS(-msse2 -mfpmath=sse)
-        include(DetectSSE2)
-        if (NOT SSE2_SUPPORT_FOUND)
-            message(FATAL_ERROR "SSE2 support is required to compile WebKit")
-        endif ()
-    endif ()
 endif ()
 
 if (COMPILER_IS_GCC_OR_CLANG AND NOT MSVC)