gcc/testsuite/gcc.target/i386/pad-2.c

/* { dg-do compile } */
/* { dg-skip-if "" { *-*-* } { "-march=*" } { "-march=atom" } } */
/* { dg-options "-O2 -fomit-frame-pointer -march=atom" } */
/* { dg-final { scan-assembler-times "nop" 8 { target { ! x86_64-*-mingw* } } } } */
/* { dg-final { scan-assembler-times "nop" 6 { target x86_64-*-mingw* } } } */
/* { dg-final { scan-assembler-not "rep" } } */

void
foo ()
{
}