arm-none-eabi-gcc will not recognize __uint128_t typedef on OS X

Hello,

I've compiled from source (using GNU gcc 4.9, not clang) and also tried the binary-- same problem. The arm-none-eabi-gcc apparently doesn't have or can't find the typedef struct for __uint128_t. Is this intended? I've scoured google but can't seem to find anybody else having this issue. When I try to grep the directory structure of the compiler, the only references I see to __uint128_t are in the docs (example below):

../../gcc-arm-none-eabi-4_9-2015q3/./share/doc/gcc-arm-none-eabi/info/gcc.info: vector __uint128_t vec_vaddcuq (vector __uint128_t, vector __uint128_t);

Is there some flag I need to use to enable support for this? I'm trying to build a kernel for the new Galaxy Note 5 (on the Exynos 7420) and I might need a different toolchain, but I figured this would be just fine.

Output of compiler is below:

[mother@osx: ~/Documents/android/SpaceX-Kernel-Exynos7420/TMB] $ make ARCH=arm64
  CHK include/generated/uapi/linux/version.h
  CHK include/generated/utsrelease.h
  CC arch/arm64/kernel/asm-offsets.s
In file included from ~/Documents/android/SpaceX-Kernel-Exynos7420/TMB/arch/arm64/include/asm/ptrace.h:22:0,
                 from ~/Documents/android/SpaceX-Kernel-Exynos7420/TMB/arch/arm64/include/asm/irqflags.h:21,
                 from include/linux/irqflags.h:15,
                 from include/linux/spinlock.h:53,
                 from include/linux/seqlock.h:29,
                 from include/linux/time.h:5,
                 from include/uapi/linux/timex.h:56,
                 from include/linux/timex.h:56,
                 from include/linux/sched.h:17,
                 from arch/arm64/kernel/asm-offsets.c:23:
~/Documents/android/SpaceX-Kernel-Exynos7420/TMB/arch/arm64/include/uapi/asm/ptrace.h:76:2: error: unknown type name '__uint128_t'
  __uint128_t vregs[32];
  ^
In file included from ~/Documents/android/SpaceX-Kernel-Exynos7420/TMB/arch/arm64/include/asm/processor.h:32:0,
                 from ~/Documents/android/SpaceX-Kernel-Exynos7420/TMB/arch/arm64/include/asm/spinlock.h:20,
                 from include/linux/spinlock.h:87,
                 from include/linux/seqlock.h:29,
                 from include/linux/time.h:5,
                 from include/uapi/linux/timex.h:56,
                 from include/linux/timex.h:56,
                 from include/linux/sched.h:17,
                 from arch/arm64/kernel/asm-offsets.c:23:
~/Documents/android/SpaceX-Kernel-Exynos7420/TMB/arch/arm64/include/asm/fpsimd.h:35:4: error: unknown type name '__uint128_t'
    __uint128_t vregs[32];
    ^
~/Documents/android/SpaceX-Kernel-Exynos7420/TMB/arch/arm64/include/asm/fpsimd.h:49:2: error: unknown type name '__uint128_t'
  __uint128_t vregs[32];
  ^
make[1]: *** [arch/arm64/kernel/asm-offsets.s] Error 1
make: *** [prepare0] Error 2