none/tests/x86/xadd.c

   1
   2 #include "config.h"
   3 #include <stdio.h>
   4 #include <assert.h>
   5
   6 /* Simple test program, no race.
   7    Tests the 'xadd' exchange-and-add instruction with {r,r} operands, which is rarely generated by compilers. */
   8
   9 #undef PLAT_x86_linux
  10 #undef PLAT_amd64_linux
  11 #undef PLAT_ppc32_linux
  12 #undef PLAT_ppc64_linux
  13
  14 #if defined(__i386__)
  15 #  define PLAT_x86_linux 1
  16 #elif defined(__x86_64__)
  17 #  define PLAT_amd64_linux 1
  18 #endif
  19
  20
  21 #if defined(PLAT_amd64_linux) || defined(PLAT_x86_linux)
  22 #  define XADD_R_R(_addr,_lval) \
  23         __asm__ __volatile__( \
  24         "xadd %1, %0" \
  25         : /*out*/ "=r"(_lval),"=r"(_addr) \
  26         : /*in*/  "0"(_lval),"1"(_addr) \
  27         : "flags" \
  28         )
  29 #else
  30 #  error "Unsupported architecture"
  31 #endif
  32
  33 int main ( void )
  34 {
  35    long d = 20, s = 2;
  36    long xadd_r_r_res;
  37 #define XADD_R_R_RES 42
  38
  39    XADD_R_R(s, d);
  40    xadd_r_r_res = s + d;
  41    assert(xadd_r_r_res == XADD_R_R_RES);
  42
  43    if (xadd_r_r_res == XADD_R_R_RES)
  44       printf("success\n");
  45    else
  46       printf("failure\n");
  47
  48    return xadd_r_r_res;
  49 }