gcc/testsuite/gcc.target/arm/frame-pointer-1.c

   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 }