The armv7 architecture should be able to deal with the armv6t2 instruction set for moving 16 bit values.

// current clang inline assembler bug for: /usr/local/bin/clang -march=armv7 -ccc-host-triple arm-apple-darwin11 -c test.c
#ifdef __arm__
int test(void) {
    int val;
    asm (
      //"mov %[r0], #0xff \n\t"              // old ARM way for 1023 constant (works)
      //"orr %[r0], %[r0], #0x300 \n\t"
      "movw %[r0], #1023 \n\t"             // new ARMv6T2 way for 16 bit wide constants
      "movt %[r0], #0 \n\t"
      :  [r0] "=r" (val)
  );
  return val;
}
#endif

Currently this results in an error:
test.c:8:7: error: instruction requires: armv6t2
      "movw %[r0], #1023 \n\t"             // new ARMv6T2 way for 16 bit wide constants
      ^
<inline asm>:1:2: note: instantiated into assembly here
        movw r0, #1023