linux/arch/x86/include/asm/elfcore-compat.h

#ifndef _ASM_X86_ELFCORE_COMPAT_H
#define _ASM_X86_ELFCORE_COMPAT_H

#include <asm/user32.h>

/*
 * On amd64 we have two 32bit ABIs - i386 and x32.  The latter
 * has bigger registers, so we use it for compat_elf_regset_t.
 * The former uses i386_elf_prstatus and PRSTATUS_SIZE/SET_PR_FPVALID
 * are used to choose the size and location of ->pr_fpvalid of
 * the layout actually used.
 */
compat_elf_gregset_t;

struct i386_elf_prstatus
{ … };

#define PRSTATUS_SIZE …
#define SET_PR_FPVALID(S) …

#endif