code: /**
   * Testing ASM VSX register number fixer '%x<n>'
   *
   * old versions of CLANG doesn't support %x<n> in the inline asm template
   * which fixes register number when using any of the register constraints wa, wd, wf.
   *
   * xref:
   * - https://bugs.llvm.org/show_bug.cgi?id=31837
   * - https://gcc.gnu.org/onlinedocs/gcc/Machine-Constraints.html
   */
  #ifndef __VSX__
      #error "VSX is not supported"
  #endif
  #include <altivec.h>
  
  #if (defined(__GNUC__) && !defined(vec_xl)) || (defined(__clang__) && !defined(__IBMC__))
      #define vsx_ld  vec_vsx_ld
      #define vsx_st  vec_vsx_st
  #else
      #define vsx_ld  vec_xl
      #define vsx_st  vec_xst
  #endif
  
  int main(void)
  {
      float z4[] = {0, 0, 0, 0};
      signed int zout[] = {0, 0, 0, 0};
  
      __vector float vz4 = vsx_ld(0, z4);
      __vector signed int asm_ret = vsx_ld(0, zout);
  
      __asm__ ("xvcvspsxws %x0,%x1" : "=wa" (vz4) : "wa" (asm_ret));
  
      vsx_st(asm_ret, 0, zout);
      return zout[0];
  }
  