Conditional Compilation in assembler (.s) code for iPhone - how?

Question

I have a few lines of assembler arm code in an .s file. Just a few routines i need to call. It works fine when building for the device, however when i switch to iPhone Simul

Answer 1

You do do it with a pre-processor macro. They are defined in TargetConditionals.h TARGET_IPHONE_SIMULATOR should be there! (You do need to #include it however.)

Answer 2

Here is code I use to detect ARM vs Thumb vs Simulator:

#include "TargetConditionals.h"

#if defined(__arm__)
# if defined(__thumb__)
#  define COMPILE_ARM_THUMB_ASM 1
# else
#  define COMPILE_ARM_ASM 1
# endif
#endif

#if TARGET_IPHONE_SIMULATOR
  // Simulator defines
#else
  // ARM or Thumb mode defines
#endif

// And here is how you might use it

uint32_t
test_compare_shifted_operand(uint32_t w1) {
  uint32_t local;
#if defined(COMPILE_ARM_ASM)
  const uint32_t shifted = (1 << 8);
  __asm__ __volatile__ (
                        "mov %[w2], #1\n\t"
                        "cmp %[w2], %[w1], lsr #8\n\t"
                        "moveq %[w2], #10\n\t"
                        "movne %[w2], #11\n\t"
                        : \
                        [w1] "+l" (w1),
                        [w2] "+l" (local)
                        : \
                        [shifted] "l" (shifted)
                        );
#else // COMPILE_ARM_ASM
  if ((w1 >> 8) == 1) {
    local = 10;
  } else {
    local = 11;
  }
#endif // COMPILE_ARM_ASM  
  return local;
}