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Diffstat (limited to 'sysdeps/unix/alpha/sysdep.S')
-rw-r--r-- | sysdeps/unix/alpha/sysdep.S | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/sysdeps/unix/alpha/sysdep.S b/sysdeps/unix/alpha/sysdep.S new file mode 100644 index 0000000000..a39ee617ce --- /dev/null +++ b/sysdeps/unix/alpha/sysdep.S @@ -0,0 +1,65 @@ +/* Copyright (C) 1993-2014 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Brendan Kehoe (brendan@zen.org). + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library. If not, see + <http://www.gnu.org/licenses/>. */ + +#include <sysdep.h> +#include <features.h> + +#if defined(PIC) + /* Put this at the end of libc's text segment so that all of + the direct branches from the syscalls are forward, and + thus predicted not taken. */ + .section .text.last, "ax", @progbits +#else + .text +#endif + +#ifndef NOT_IN_libc +# define SYSCALL_ERROR_ERRNO __libc_errno +#else +# define SYSCALL_ERROR_ERRNO errno +#endif + + .align 4 + .globl __syscall_error + .ent __syscall_error +__syscall_error: + /* When building a shared library, we branch here without having + loaded the GP. Nor, since it was a direct branch, have we + loaded PV with our address. + + When building a static library, we tail call here from another + object file, possibly with a different GP, and must return with + the GP of our caller in place so that linker relaxation works. + + Both issues are solved by computing the GP into T1 instead of + clobbering the traditional GP register. */ + .prologue 0 + mov v0, t0 + br t1, 1f +1: ldah t1, 0(t1) !gpdisp!1 + call_pal PAL_rduniq + + lda t1, 0(t1) !gpdisp!1 + ldq t1, SYSCALL_ERROR_ERRNO(t1) !gottprel + addq v0, t1, t1 + lda v0, -1 + + stl t0, 0(t1) + ret + + .end __syscall_error |