gcc/testsuite/g++.dg/pr71694.C

   1 /* { dg-do compile } */
   2 /* { dg-options "-O2 -fno-store-merging" } */
   3
   4 struct B {
   5     B() {}
   6     int x;
   7     int a : 6;
   8     int b : 6;
   9     int c : 6;
  10 };
  11
  12 struct C : B {
  13     char d;
  14 };
  15
  16 C c;
  17
  18 int main()
  19 {
  20   /* We have to make sure to not cause a store data race between
  21      c.c and c.d residing in the tail padding of B.  */
  22   c.c = 1;
  23   c.d = 2;
  24 }
  25
  26 /* In particular on x86 c.d should not be loaded/stored via movl.  */
  27 /* { dg-final { scan-assembler-not "movl" { target { x86_64-*-* i?86-*-* } } } } */