gcc/testsuite/gcc.target/arm/thumb-find-work-register.c

   1 /* Wrong method to get number of arg reg will cause argument corruption.  */
   2 /* { dg-do run } */
   3 /* { dg-skip-if "incompatible options" { ! { arm_thumb1_ok || arm_thumb2_ok } } } */
   4 /* { dg-require-effective-target arm_eabi } */
   5 /* { dg-options "-mthumb -O1" } */
   6
   7 extern void abort (void);
   8
   9 int foo (int, int, int, int) __attribute__((noinline));
  10
  11 int
  12 foo (int a, int b, int c, int d)
  13 {
  14   register int m asm ("r8");
  15
  16   m = a;
  17   m += b;
  18   m += c;
  19   m += d;
  20
  21   asm ("" : "=r" (m) : "0" (m));
  22
  23   return m;
  24 }
  25
  26 int
  27 main ()
  28 {
  29   volatile int a = 10;
  30   volatile int b = 20;
  31   volatile int c = 30;
  32   volatile int d = 40;
  33   volatile int sum = 0;
  34
  35   sum = foo (a, b, c, d);
  36
  37   if (sum != 100)
  38     abort ();
  39
  40   return 0;
  41 }