1  /* Check local register variables using a register conventionally 
       2     used as the frame pointer aren't clobbered under high register pressure.  */
       3  /* { dg-do run } */
       4  /* { dg-skip-if "incompatible options" { ! { arm_thumb1_ok || arm_thumb2_ok } } } */
       5  /* { dg-options "-Os -mthumb -fomit-frame-pointer" } */
       6  
       7  #include <stdlib.h>
       8  
       9  int global=5;
      10  
      11  void __attribute__((noinline)) foo(int p1, int p2, int p3, int p4)
      12  {
      13    if (global != 5 || p1 != 1 || p2 != 2 || p3 != 3 || p4 != 4)
      14      abort();
      15  }
      16  
      17  int __attribute__((noinline)) test(int a, int b, int c, int d)
      18  {
      19    register unsigned long r __asm__("r7") = 0xdeadbeef;
      20    int e;
      21  
      22    /* ABCD are live after the call which should be enough
      23       to cause r7 to be used if it weren't for the register variable.  */
      24    foo(a,b,c,d);
      25  
      26    e = 0;
      27    __asm__ __volatile__ ("mov %0, %2"
      28  			: "=r" (e)
      29  			: "0" (e), "r" (r));
      30  
      31    global = a+b+c+d;
      32  
      33    return e;
      34  }
      35  
      36  int main()
      37  {
      38    if (test(1, 2, 3, 4) != 0xdeadbeef)
      39      abort();
      40    if (global != 10)
      41      abort();
      42    return 0;
      43  }