gcc/testsuite/gcc.target/powerpc/shrink-wrap-separate-2.c

   1 /* { dg-do compile { target powerpc*-*-* } } */
   2 /* { dg-options "-O2" } */
   3 /* { dg-final { scan-assembler {\mmflr\M.*\mbl\M.*\mmflr\M.*\mbl\M} } } */
   4
   5 /* This tests if shrink-wrapping for separate components puts a prologue
   6    inside a loop when that is useful.  In this case, it saves the link
   7    register before each call: both calls happen with probability .10,
   8    so saving the link register happens with .80 per execution of f on
   9    average, which is smaller than 1 which you would get if you saved
  10    it outside the loop.  */
  11
  12 int *a;
  13 void g(void);
  14
  15 void f(int x)
  16 {
  17         int j;
  18         for (j = 0; j < 4; j++) {
  19                 if (__builtin_expect(a[j], 0))
  20                         g();
  21                 asm("#" : : : "memory");
  22                 if (__builtin_expect(a[j], 0))
  23                         g();
  24                 a[j]++;
  25         }
  26 }