gcc/testsuite/gcc.target/i386/zero-scratch-regs-1.c

/* { dg-do compile { target *-*-linux* } } */
/* { dg-options "-O2 -fzero-call-used-regs=used" } */

void
foo (void)
{
}

/* { dg-final { scan-assembler-not "vzeroall" } } */
/* { dg-final { scan-assembler-not "%xmm" } } */
/* { dg-final { scan-assembler-not "xorl\[ \t\]+%" } } */
/* { dg-final { scan-assembler-not "movl\[ \t\]+%" } } */