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fb1cf10811
For ia32 PIC, the first thing of many syscalls does is to call __x86.get_pc_thunk.reg to load PC into reg in case there is an error, which is required for setting errno. In most cases, there are no errors. But we still call __x86.get_pc_thunk.reg. This patch adds INLINE_SYSCALL_ERROR_RETURN_VALUE so that i386 can optimize setting errno by branching to the internal __syscall_error without PLT. With i386 INLINE_SYSCALL_ERROR_RETURN_VALUE and i386 syscall inlining optimization for GCC 5, for sysdeps/unix/sysv/linux/fchmodat.c with -O2 -march=i686 -mtune=generic, GCC 5.2 now generates: <fchmodat>: 0: push %ebx 1: mov 0x14(%esp),%eax 5: mov 0x8(%esp),%ebx 9: mov 0xc(%esp),%ecx d: mov 0x10(%esp),%edx 11: test $0xfffffeff,%eax 16: jne 38 <fchmodat+0x38> 18: test $0x1,%ah 1b: jne 48 <fchmodat+0x48> 1d: mov $0x132,%eax 22: call *%gs:0x10 29: cmp $0xfffff000,%eax 2e: ja 58 <fchmodat+0x58> 30: pop %ebx 31: ret 32: lea 0x0(%esi),%esi 38: pop %ebx 39: mov $0xffffffea,%eax 3e: jmp 3f <fchmodat+0x3f> 3f: R_386_PC32 __syscall_error 43: nop 44: lea 0x0(%esi,%eiz,1),%esi 48: pop %ebx 49: mov $0xffffffa1,%eax 4e: jmp 4f <fchmodat+0x4f> 4f: R_386_PC32 __syscall_error 53: nop 54: lea 0x0(%esi,%eiz,1),%esi 58: pop %ebx 59: jmp 5a <fchmodat+0x5a> 5a: R_386_PC32 __syscall_error instead of <fchmodat>: 0: sub $0x8,%esp 3: mov 0x18(%esp),%eax 7: mov %ebx,(%esp) a: call b <fchmodat+0xb> b: R_386_PC32 __x86.get_pc_thunk.bx f: add $0x2,%ebx 11: R_386_GOTPC _GLOBAL_OFFSET_TABLE_ 15: mov %edi,0x4(%esp) 19: test $0xfffffeff,%eax 1e: jne 70 <fchmodat+0x70> 20: test $0x1,%ah 23: jne 88 <fchmodat+0x88> 25: mov 0x14(%esp),%edx 29: mov 0x10(%esp),%ecx 2d: mov 0xc(%esp),%edi 31: xchg %ebx,%edi 33: mov $0x132,%eax 38: call *%gs:0x10 3f: xchg %edi,%ebx 41: cmp $0xfffff000,%eax 46: ja 58 <fchmodat+0x58> 48: mov (%esp),%ebx 4b: mov 0x4(%esp),%edi 4f: add $0x8,%esp 52: ret 53: nop 54: lea 0x0(%esi,%eiz,1),%esi 58: mov 0x0(%ebx),%edx 5a: R_386_TLS_GOTIE __libc_errno 5e: neg %eax 60: mov %eax,%gs:(%edx) 63: mov $0xffffffff,%eax 68: jmp 48 <fchmodat+0x48> 6a: lea 0x0(%esi),%esi 70: mov 0x0(%ebx),%eax 72: R_386_TLS_GOTIE __libc_errno 76: movl $0x16,%gs:(%eax) 7d: mov $0xffffffff,%eax 82: jmp 48 <fchmodat+0x48> 84: lea 0x0(%esi,%eiz,1),%esi 88: mov 0x0(%ebx),%eax 8a: R_386_TLS_GOTIE __libc_errno 8e: movl $0x5f,%gs:(%eax) 95: mov $0xffffffff,%eax 9a: jmp 48 <fchmodat+0x48> * sysdeps/unix/sysv/linux/sysdep.h: New file. * sysdeps/unix/sysv/linux/i386/sysdep.c: Likewise. * sysdeps/unix/sysv/linux/alpha/sysdep.h: Include <sysdeps/unix/sysv/linux/sysdep.h>. * sysdeps/unix/sysv/linux/arm/sysdep.h: Likewise. * sysdeps/unix/sysv/linux/generic/sysdep.h: Likewise. * sysdeps/unix/sysv/linux/hppa/sysdep.h: Likewise. * sysdeps/unix/sysv/linux/ia64/sysdep.h: Likewise. * sysdeps/unix/sysv/linux/m68k/sysdep.h: Likewise. * sysdeps/unix/sysv/linux/microblaze/sysdep.h: Likewise. * sysdeps/unix/sysv/linux/mips/mips32/sysdep.h: Likewise. * sysdeps/unix/sysv/linux/mips/mips64/n32/sysdep.h: Likewise. * sysdeps/unix/sysv/linux/mips/mips64/n64/sysdep.h: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep.h: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h: Likewise. * sysdeps/unix/sysv/linux/s390/s390-32/sysdep.h: Likewise. * sysdeps/unix/sysv/linux/s390/s390-64/sysdep.h: Likewise. * sysdeps/unix/sysv/linux/sh/sysdep.h: Likewise. * sysdeps/unix/sysv/linux/sparc/sysdep.h: Likewise. * sysdeps/unix/sysv/linux/x86_64/sysdep.h: Likewise. * sysdeps/unix/sysv/linux/i386/Makefile [$(subdir) == csu] (sysdep-dl-routines): Add sysdep. [$(subdir) == nptl] (libpthread-routines): Likewise. [$(subdir) == rt] (librt-routines): Likewise. * sysdeps/unix/sysv/linux/i386/clone.S (__clone): Don't check PIC when branching to SYSCALL_ERROR_LABEL. * sysdeps/unix/sysv/linux/i386/sysdep.S: Removed. * sysdeps/unix/sysv/linux/i386/sysdep.h: Include <sysdeps/unix/sysv/linux/sysdep.h>. (SYSCALL_ERROR_LABEL): Changed to __syscall_error. (SYSCALL_ERROR_ERRNO): Removed. (SYSCALL_ERROR_HANDLER): Changed to empty. (SYSCALL_ERROR_HANDLER_TLS_STORE): Likewise. (__syscall_error): New prototype. [IS_IN (libc)] (INLINE_SYSCALL): New macro. (INLINE_SYSCALL_ERROR_RETURN_VALUE): Likewise. |
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|---|---|---|
| .. | ||
| bits | ||
| sys | ||
| ____longjmp_chk.S | ||
| __ia64_longjmp.S | ||
| __longjmp.S | ||
| __sigstack_longjmp.c | ||
| __start_context.S | ||
| arch-fork.h | ||
| brk.S | ||
| bsd-_setjmp.S | ||
| bsd-setjmp.S | ||
| c++-types.data | ||
| clone2.S | ||
| clone.S | ||
| configure | ||
| configure.ac | ||
| dl-brk.S | ||
| dl-cache.h | ||
| dl-static.c | ||
| dl-sysdep.h | ||
| get_clockfreq.c | ||
| getclktck.c | ||
| getcontext.S | ||
| has_cpuclock.c | ||
| Implies | ||
| ioperm.c | ||
| kernel_stat.h | ||
| kernel-features.h | ||
| ld.abilist | ||
| ldconfig.h | ||
| ldd-rewrite.sed | ||
| ldsodefs.h | ||
| libanl.abilist | ||
| libBrokenLocale.abilist | ||
| libc.abilist | ||
| libcrypt.abilist | ||
| libdl.abilist | ||
| libm.abilist | ||
| libnsl.abilist | ||
| libpthread.abilist | ||
| libresolv.abilist | ||
| librt.abilist | ||
| libthread_db.abilist | ||
| libutil.abilist | ||
| localplt.data | ||
| makecontext.c | ||
| Makefile | ||
| pipe.S | ||
| profil-counter.h | ||
| pt-vfork.S | ||
| readelflib.c | ||
| register-dump.h | ||
| rt-sysdep.S | ||
| setcontext.S | ||
| setjmp.S | ||
| shlib-versions | ||
| sigaction.c | ||
| sigaltstack-offsets.sym | ||
| sigcontext-offsets.sym | ||
| sigcontextinfo.h | ||
| sigpending.c | ||
| sigprocmask.c | ||
| swapcontext.c | ||
| syscall.S | ||
| syscalls.list | ||
| sysconf.c | ||
| sysdep-cancel.h | ||
| sysdep.h | ||
| sysdep.S | ||
| system.c | ||
| timer_create.c | ||
| timer_delete.c | ||
| timer_getoverr.c | ||
| timer_gettime.c | ||
| timer_settime.c | ||
| ucontext_i.h | ||
| umount.c | ||
| unwind_longjmp.c | ||
| unwind-dw2-fde.c | ||
| unwind-forcedunwind.c | ||
| Versions | ||
| vfork.S | ||
| wordexp.c | ||