diff --git a/thcrap/src/compiler_support.h b/thcrap/src/compiler_support.h
index e96fd5ec..93291594 100644
--- a/thcrap/src/compiler_support.h
+++ b/thcrap/src/compiler_support.h
@@ -136,6 +136,15 @@
 #define __has_c_attribute(attr) 0
 #endif
 
+// C attributes support namespaces according to the C2X
+// standard, but MSVC toolsets fail to parse namespaces
+// in that location anyway when not parsing as C++.
+#if !defined(__cplusplus) && (MSVC_COMPAT && !GCC_COMPAT && !CLANG_COMPAT && !MINGW_COMPAT && !ICC_COMPAT)
+#define __has_c_attribute_with_namespace(attr) 0
+#else
+#define __has_c_attribute_with_namespace(attr) __has_c_attribute(attr)
+#endif
+
 // - GNU Attributes
 #ifndef __has_attribute
 #define __has_attribute(attr) 0
@@ -283,7 +292,7 @@
 // - [[likely]] Equivalent Attributes
 #if __has_cpp_attribute(likely) >= 201803L
 #define TH_LIKELY [[likely]]
-#elif __has_c_attribute(clang::likely)
+#elif __has_c_attribute_with_namespace(clang::likely)
 #define TH_LIKELY [[clang::likely]]
 #else
 #define TH_LIKELY
@@ -292,7 +301,7 @@
 // - [[unlikely]] Equivalent Attributes
 #if __has_cpp_attribute(unlikely) >= 201803L
 #define TH_UNLIKELY [[unlikely]]
-#elif __has_c_attribute(clang::unlikely)
+#elif __has_c_attribute_with_namespace(clang::unlikely)
 #define TH_UNLIKELY [[clang::unlikely]]
 #else
 #define TH_UNLIKELY
@@ -542,49 +551,59 @@ extern "C++" {
 #define read_fs_byte(offset) (*(uint8_t __attribute__((address_space(257)))*)((uintptr_t)offset))
 #define read_fs_word(offset) (*(uint16_t __attribute__((address_space(257)))*)((uintptr_t)offset))
 #define read_fs_dword(offset) (*(uint32_t __attribute__((address_space(257)))*)((uintptr_t)offset))
+#define read_fs_qword(offset) (*(uint64_t __attribute__((address_space(257)))*)((uintptr_t)offset))
 #define write_fs_byte(offset, data) ((void)(*(uint8_t __attribute__((address_space(257)))*)((uintptr_t)offset) = (uint8_t)(data)))
 #define write_fs_word(offset, data) ((void)(*(uint16_t __attribute__((address_space(257)))*)((uintptr_t)offset) = (uint16_t)(data)))
 #define write_fs_dword(offset, data) ((void)(*(uint32_t __attribute__((address_space(257)))*)((uintptr_t)offset) = (uint32_t)(data)))
-#elif defined(__SEG_FS) && (CLANG_COMPAT || !defined(__cplusplus)) // __seg_fs isn't recognized by GCC when compiling C++
+#define write_fs_qword(offset, data) ((void)(*(uint64_t __attribute__((address_space(257)))*)((uintptr_t)offset) = (uint64_t)(data)))
+#elif defined(__SEG_FS)
+#if CLANG_COMPAT || !defined(__cplusplus) // __seg_fs isn't recognized by GCC when compiling C++
 #define read_fs_byte(offset) (*(__seg_fs uint8_t*)((uintptr_t)offset))
 #define read_fs_word(offset) (*(__seg_fs uint16_t*)((uintptr_t)offset))
 #define read_fs_dword(offset) (*(__seg_fs uint32_t*)((uintptr_t)offset))
+#define read_fs_qword(offset) (*(__seg_fs uint64_t*)((uintptr_t)offset))
 #define write_fs_byte(offset, data) ((void)(*(__seg_fs uint8_t*)((uintptr_t)offset) = (uint8_t)(data)))
 #define write_fs_word(offset, data) ((void)(*(__seg_fs uint16_t*)((uintptr_t)offset) = (uint16_t)(data)))
 #define write_fs_dword(offset, data) ((void)(*(__seg_fs uint32_t*)((uintptr_t)offset) = (uint32_t)(data)))
-#elif GCC_COMPAT
-#ifdef __cplusplus
+#define write_fs_qword(offset, data) ((void)(*(__seg_fs uint64_t*)((uintptr_t)offset) = (uint64_t)(data)))
+#else
 extern "C" {
-#endif
-#define read_fs_byte(offset) read_fs_byte_gcc(offset)
-#define read_fs_word(offset) read_fs_word_gcc(offset)
-#define read_fs_dword(offset) read_fs_dword_gcc(offset)
-#define write_fs_byte(offset, data) write_fs_byte_gcc(offset, data)
-#define write_fs_word(offset, data) write_fs_word_gcc(offset, data)
-#define write_fs_dword(offset, data) write_fs_dword_gcc(offset, data)
 uint8_t read_fs_byte_gcc(size_t offset);
 uint16_t read_fs_word_gcc(size_t offset);
 uint32_t read_fs_dword_gcc(size_t offset);
+uint32_t read_fs_qword_gcc(size_t offset);
 void write_fs_byte_gcc(size_t offset, uint8_t data);
 void write_fs_word_gcc(size_t offset, uint16_t data);
 void write_fs_dword_gcc(size_t offset, uint32_t data);
-#ifdef __cplusplus
+void write_fs_qword_gcc(size_t offset, uint32_t data);
 };
+#define read_fs_byte(offset) read_fs_byte_gcc(offset)
+#define read_fs_word(offset) read_fs_word_gcc(offset)
+#define read_fs_dword(offset) read_fs_dword_gcc(offset)
+#define read_fs_qword(offset) read_fs_qword_gcc(offset)
+#define write_fs_byte(offset, data) write_fs_byte_gcc(offset, data)
+#define write_fs_word(offset, data) write_fs_word_gcc(offset, data)
+#define write_fs_dword(offset, data) write_fs_dword_gcc(offset, data)
+#define write_fs_qword(offset, data) write_fs_qword_gcc(offset, data)
 #endif
 #elif MSVC_COMPAT
 #define read_fs_byte(offset) __readfsbyte(offset)
 #define read_fs_word(offset) __readfsword(offset)
 #define read_fs_dword(offset) __readfsdword(offset)
+#define read_fs_qword(offset) __readfsqword(offset)
 #define write_fs_byte(offset, data) __writefsbyte(offset, data)
 #define write_fs_word(offset, data) __writefsword(offset, data)
 #define write_fs_dword(offset, data) __writefsdword(offset, data)
+#define write_fs_qword(offset, data) __writefsqword(offset, data)
 #else
 #define read_fs_byte(offset) (*(uint8_t*)((uintptr_t)offset))
 #define read_fs_word(offset) (*(uint16_t*)((uintptr_t)offset))
 #define read_fs_dword(offset) (*(uint32_t*)((uintptr_t)offset))
+#define read_fs_qword(offset) (*(uint64_t*)((uintptr_t)offset))
 #define write_fs_byte(offset, data) ((void)(*(uint8_t*)((uintptr_t)offset) = (uint8_t)(data)))
 #define write_fs_word(offset, data) ((void)(*(uint16_t*)((uintptr_t)offset) = (uint16_t)(data)))
 #define write_fs_dword(offset, data) ((void)(*(uint32_t*)((uintptr_t)offset) = (uint32_t)(data)))
+#define write_fs_qword(offset, data) ((void)(*(uint64_t*)((uintptr_t)offset) = (uint64_t)(data)))
 #endif
 #if __has_attribute(address_space)
 #define read_gs_byte(offset) (*(uint8_t __attribute__((address_space(256)))*)((uintptr_t)offset))
@@ -595,7 +614,8 @@ void write_fs_dword_gcc(size_t offset, uint32_t data);
 #define write_gs_word(offset, data) ((void)(*(uint16_t __attribute__((address_space(256)))*)((uintptr_t)offset) = (uint16_t)(data)))
 #define write_gs_dword(offset, data) ((void)(*(uint32_t __attribute__((address_space(256)))*)((uintptr_t)offset) = (uint32_t)(data)))
 #define write_gs_qword(offset, data) ((void)(*(uint64_t __attribute__((address_space(256)))*)((uintptr_t)offset) = (uint64_t)(data)))
-#elif defined(__SEG_GS) && (CLANG_COMPAT || !defined(__cplusplus)) // __seg_gs isn't recognized by GCC when compiling C++
+#elif defined(__SEG_GS)
+#if CLANG_COMPAT || !defined(__cplusplus) // __seg_gs isn't recognized by GCC when compiling C++
 #define read_gs_byte(offset) (*(__seg_gs uint8_t*)((uintptr_t)offset))
 #define read_gs_word(offset) (*(__seg_gs uint16_t*)((uintptr_t)offset))
 #define read_gs_dword(offset) (*(__seg_gs uint32_t*)((uintptr_t)offset))
@@ -604,18 +624,8 @@ void write_fs_dword_gcc(size_t offset, uint32_t data);
 #define write_gs_word(offset, data) ((void)(*(__seg_gs uint16_t*)((uintptr_t)offset) = (uint16_t)(data)))
 #define write_gs_dword(offset, data) ((void)(*(__seg_gs uint32_t*)((uintptr_t)offset) = (uint32_t)(data)))
 #define write_gs_qword(offset, data) ((void)(*(__seg_gs uint64_t*)((uintptr_t)offset) = (uint64_t)(data)))
-#elif GCC_COMPAT
-#ifdef __cplusplus
+#else
 extern "C" {
-#endif
-#define read_gs_byte(offset) read_gs_byte_gcc(offset)
-#define read_gs_word(offset) read_gs_word_gcc(offset)
-#define read_gs_dword(offset) read_gs_dword_gcc(offset)
-#define read_gs_qword(offset) read_gs_qword_gcc(offset)
-#define write_gs_byte(offset, data) write_gs_byte_gcc(offset, data)
-#define write_gs_word(offset, data) write_gs_word_gcc(offset, data)
-#define write_gs_dword(offset, data) write_gs_dword_gcc(offset, data)
-#define write_gs_qword(offset, data) write_gs_qword_gcc(offset, data)
 uint8_t read_gs_byte_gcc(size_t offset);
 uint16_t read_gs_word_gcc(size_t offset);
 uint32_t read_gs_dword_gcc(size_t offset);
@@ -624,8 +634,15 @@ void write_gs_byte_gcc(size_t offset, uint8_t data);
 void write_gs_word_gcc(size_t offset, uint16_t data);
 void write_gs_dword_gcc(size_t offset, uint32_t data);
 void write_gs_qword_gcc(size_t offset, uint64_t data);
-#ifdef __cplusplus
 };
+#define read_gs_byte(offset) read_gs_byte_gcc(offset)
+#define read_gs_word(offset) read_gs_word_gcc(offset)
+#define read_gs_dword(offset) read_gs_dword_gcc(offset)
+#define read_gs_qword(offset) read_gs_qword_gcc(offset)
+#define write_gs_byte(offset, data) write_gs_byte_gcc(offset, data)
+#define write_gs_word(offset, data) write_gs_word_gcc(offset, data)
+#define write_gs_dword(offset, data) write_gs_dword_gcc(offset, data)
+#define write_gs_qword(offset, data) write_gs_qword_gcc(offset, data)
 #endif
 #elif MSVC_COMPAT
 #define read_gs_byte(offset) __readgsbyte(offset)
@@ -647,7 +664,7 @@ void write_gs_qword_gcc(size_t offset, uint64_t data);
 #define write_gs_qword(offset, data) ((void)(*(uint64_t*)((uintptr_t)offset) = (uint64_t)(data)))
 #endif
 
-#ifdef GCC_COMPAT
+#if GCC_COMPAT
 #ifndef __sptr
 #define __sptr
 #endif
diff --git a/thcrap/src/gcc_gs.c b/thcrap/src/gcc_gs.c
index 7c618c59..bc5c1aae 100644
--- a/thcrap/src/gcc_gs.c
+++ b/thcrap/src/gcc_gs.c
@@ -1,7 +1,7 @@
 #include "compiler_support.h"
 
 /*
- * This file is compiled in GCC in C mode - where __seg_gc works.
+ * This file is compiled in GCC in C mode - where __seg_fs/__seg_gs works.
  * So we'll juts use our C macro.
  */
 
@@ -20,6 +20,10 @@ uint32_t read_fs_dword_gcc(size_t offset)
 	return read_fs_dword(offset);
 }
 
+uint64_t read_fs_qword_gcc(size_t offset) {
+	return read_fs_qword(offset);
+}
+
 void write_fs_byte_gcc(size_t offset, uint8_t data)
 {
 	write_fs_byte(offset, data);
@@ -35,6 +39,10 @@ void write_fs_dword_gcc(size_t offset, uint32_t data)
 	write_fs_dword(offset, data);
 }
 
+void write_fs_qword_gcc(size_t offset, uint64_t data) {
+	write_fs_qword(offset, data);
+}
+
 uint8_t read_gs_byte_gcc(size_t offset)
 {
 	return read_gs_byte(offset);