[03/21] ARC: ABI Implementation

Message ID 1545167083-16764-4-git-send-email-vgupta@synopsys.com
State New
Headers show
Series
  • glibc port to ARC processors
Related show

Commit Message

Vineet Gupta Dec. 18, 2018, 9:04 p.m.
This code deals with the ARC ABI.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

---
 ChangeLog                    | 20 ++++++++++++
 sysdeps/arc/__longjmp.S      | 50 ++++++++++++++++++++++++++++
 sysdeps/arc/abort-instr.h    |  2 ++
 sysdeps/arc/bits/endian.h    | 12 +++++++
 sysdeps/arc/bits/setjmp.h    | 33 +++++++++++++++++++
 sysdeps/arc/bsd-_setjmp.S    |  1 +
 sysdeps/arc/bsd-setjmp.S     |  1 +
 sysdeps/arc/crti.S           | 77 ++++++++++++++++++++++++++++++++++++++++++++
 sysdeps/arc/crtn.S           | 56 ++++++++++++++++++++++++++++++++
 sysdeps/arc/dl-runtime.c     | 21 ++++++++++++
 sysdeps/arc/dl-sysdep.h      | 25 ++++++++++++++
 sysdeps/arc/dl-trampoline.S  | 72 +++++++++++++++++++++++++++++++++++++++++
 sysdeps/arc/gccframe.h       | 21 ++++++++++++
 sysdeps/arc/gmp-mparam.h     | 23 +++++++++++++
 sysdeps/arc/jmpbuf-offsets.h | 46 ++++++++++++++++++++++++++
 sysdeps/arc/jmpbuf-unwind.h  | 47 +++++++++++++++++++++++++++
 sysdeps/arc/machine-gmon.h   | 33 +++++++++++++++++++
 sysdeps/arc/memusage.h       | 23 +++++++++++++
 sysdeps/arc/setjmp.S         | 64 ++++++++++++++++++++++++++++++++++++
 sysdeps/arc/sysdep.h         | 49 ++++++++++++++++++++++++++++
 sysdeps/arc/tls-macros.h     | 29 +++++++++++++++++
 21 files changed, 705 insertions(+)
 create mode 100644 sysdeps/arc/__longjmp.S
 create mode 100644 sysdeps/arc/abort-instr.h
 create mode 100644 sysdeps/arc/bits/endian.h
 create mode 100644 sysdeps/arc/bits/setjmp.h
 create mode 100644 sysdeps/arc/bsd-_setjmp.S
 create mode 100644 sysdeps/arc/bsd-setjmp.S
 create mode 100644 sysdeps/arc/crti.S
 create mode 100644 sysdeps/arc/crtn.S
 create mode 100644 sysdeps/arc/dl-runtime.c
 create mode 100644 sysdeps/arc/dl-sysdep.h
 create mode 100644 sysdeps/arc/dl-trampoline.S
 create mode 100644 sysdeps/arc/gccframe.h
 create mode 100644 sysdeps/arc/gmp-mparam.h
 create mode 100644 sysdeps/arc/jmpbuf-offsets.h
 create mode 100644 sysdeps/arc/jmpbuf-unwind.h
 create mode 100644 sysdeps/arc/machine-gmon.h
 create mode 100644 sysdeps/arc/memusage.h
 create mode 100644 sysdeps/arc/setjmp.S
 create mode 100644 sysdeps/arc/sysdep.h
 create mode 100644 sysdeps/arc/tls-macros.h

-- 
2.7.4

Comments

Joseph Myers Dec. 18, 2018, 11:09 p.m. | #1
On Tue, 18 Dec 2018, Vineet Gupta wrote:

> +/* FLAG 1 is privilege mode only instruction, hence will crash any program */


Generally, throughout the port, make sure comments end ".  " (full stop, 
two spaces, end of comment).  I won't remark on other places with this 
formatting issue.

> diff --git a/sysdeps/arc/crti.S b/sysdeps/arc/crti.S


As a new port I think it would be best to use init_array in your Implies 
file so you don't need these crti / crtn files, and make GCC generate 
init_array / fini_array exclusively.  (See RISC-V and C-Sky discussions of 
this issue.)

> +#ifdef __A7__

> +#define ARC_PLT_SIZE	12

> +#else

> +#define ARC_PLT_SIZE	16

> +#endif


Except for the multiple-include guards round a whole header file, 
preprocessor directives inside #if should have indentation in glibc, so 
"# define" (and "#  define" inside two levels of #if, etc.).  (As usual, 
fix this throughout the port; I won't list other individual places with 
this issue.)

> +#define reloc_index					\

> +({							\

> +  unsigned long plt0 = D_PTR (l, l_info[DT_PLTGOT]);	\

> +  unsigned long pltn = reloc_arg;			\

> +  /* exclude PL0 and PLT1 */				\


Note the first letter of a comment should be capitalized (in addition to 
ending with ".  ").

> +  unsigned long idx = (pltn - plt0)/ARC_PLT_SIZE - 2;	\


glibc style uses "unsigned long int", not just "unsigned long".

> diff --git a/sysdeps/arc/tls-macros.h b/sysdeps/arc/tls-macros.h

> new file mode 100644

> index 000000000000..51855edef6e7

> --- /dev/null

> +++ b/sysdeps/arc/tls-macros.h

> @@ -0,0 +1,29 @@

> +/* Macros to support TLS testing in times of missing compiler support.  */


Any file more than ten lines long should have copyright and license 
notices.

-- 
Joseph S. Myers
joseph@codesourcery.com
Vineet Gupta Dec. 19, 2018, 2 a.m. | #2
On 12/18/18 3:09 PM, Joseph Myers wrote:
> On Tue, 18 Dec 2018, Vineet Gupta wrote:

> 

>> +/* FLAG 1 is privilege mode only instruction, hence will crash any program */

> 

> Generally, throughout the port, make sure comments end ".  " (full stop, 

> two spaces, end of comment).  I won't remark on other places with this 

> formatting issue.


OK. Fixed series wide.

>> diff --git a/sysdeps/arc/crti.S b/sysdeps/arc/crti.S

> 

> As a new port I think it would be best to use init_array in your Implies 

> file so you don't need these crti / crtn files, and make GCC generate 

> init_array / fini_array exclusively.  (See RISC-V and C-Sky discussions of 

> this issue.)


OK I can try enabling this !

>> +#ifdef __A7__

>> +#define ARC_PLT_SIZE	12

>> +#else

>> +#define ARC_PLT_SIZE	16

>> +#endif

> 

> Except for the multiple-include guards round a whole header file, 

> preprocessor directives inside #if should have indentation in glibc, so 

> "# define" (and "#  define" inside two levels of #if, etc.).  (As usual, 

> fix this throughout the port; I won't list other individual places with 

> this issue.)


Done series wide.

> 

>> +#define reloc_index					\

>> +({							\

>> +  unsigned long plt0 = D_PTR (l, l_info[DT_PLTGOT]);	\

>> +  unsigned long pltn = reloc_arg;			\

>> +  /* exclude PL0 and PLT1 */				\

> 

> Note the first letter of a comment should be capitalized (in addition to 

> ending with ".  ").

> 

>> +  unsigned long idx = (pltn - plt0)/ARC_PLT_SIZE - 2;	\

> 

> glibc style uses "unsigned long int", not just "unsigned long".


Done series wide.

>> diff --git a/sysdeps/arc/tls-macros.h b/sysdeps/arc/tls-macros.h

>> new file mode 100644

>> index 000000000000..51855edef6e7

>> --- /dev/null

>> +++ b/sysdeps/arc/tls-macros.h

>> @@ -0,0 +1,29 @@

>> +/* Macros to support TLS testing in times of missing compiler support.  */

> 

> Any file more than ten lines long should have copyright and license 

> notices.


Done.

P.S. Is there a lint file or are these style guidelines in wiki somewhere. If not
I can volunteer to capture them in a wiki/readme for future port submissions.
Joseph Myers Dec. 19, 2018, 5:40 p.m. | #3
On Tue, 18 Dec 2018, Vineet Gupta wrote:

> P.S. Is there a lint file or are these style guidelines in wiki 

> somewhere. If not I can volunteer to capture them in a wiki/readme for 

> future port submissions.


In addition to the GNU Coding Standards (which cover many things such as 
comment formatting and spaces before '('), we have 
<https://sourceware.org/glibc/wiki/Style_and_Conventions> which discusses 
various glibc-specific details.  If you find there are points of the style 
in glibc which aren't documented in either place, then, yes, it would be a 
good idea to add them to the wiki (I just added a few).

Architecture maintainers need wiki accounts in any case (to post test 
results for their architectures during every release freeze period), so 
you should create an account and post its name so someone can add it to 
EditorGroup so you can edit.

Where the formatting issues pointed out exist in some existing code in 
glibc, it might also make sense to fix that existing code to follow the 
standards more closely so it provides a better example for new code.  
However, such formatting changes to existing code may be controversial 
(especially for code that originally came from third-party sources using 
completely different formatting - though in my view, where such files are 
now maintained in glibc without ongoing updates from upstream, we ought to 
make the formatting consistent to simplify maintenance).

-- 
Joseph S. Myers
joseph@codesourcery.com
Vineet Gupta Dec. 19, 2018, 8:20 p.m. | #4
On 12/19/18 9:40 AM, Joseph Myers wrote:
> Architecture maintainers need wiki accounts in any case (to post test 

> results for their architectures during every release freeze period), so 

> you should create an account and post its name so someone can add it to 

> EditorGroup so you can edit.


Created now: VineetGupta

Thx,
-Vineet
Joseph Myers Dec. 19, 2018, 8:37 p.m. | #5
On Wed, 19 Dec 2018, Vineet Gupta wrote:

> On 12/19/18 9:40 AM, Joseph Myers wrote:

> > Architecture maintainers need wiki accounts in any case (to post test 

> > results for their architectures during every release freeze period), so 

> > you should create an account and post its name so someone can add it to 

> > EditorGroup so you can edit.

> 

> Created now: VineetGupta


Added to EditorGroup.

-- 
Joseph S. Myers
joseph@codesourcery.com
Vineet Gupta Jan. 28, 2019, 11:03 p.m. | #6
On 12/18/18 3:09 PM, Joseph Myers wrote:
>> diff --git a/sysdeps/arc/crti.S b/sysdeps/arc/crti.S

> As a new port I think it would be best to use init_array in your Implies 

> file so you don't need these crti / crtn files, and make GCC generate 

> init_array / fini_array exclusively.  (See RISC-V and C-Sky discussions of 

> this issue.)

> 


I did the switch and while is working, there are additional test failures

| FAIL: dlfcn/bug-atexit1
| FAIL: dlfcn/bug-atexit2
| FAIL: dlfcn/tstatexit
| FAIL: dlfcn/tstcxaatexit
| FAIL: nptl/tst-atfork2
| FAIL: nptl/tst-cond17
| FAIL: stdlib/test-dlclose-exit-race

In the failing case, the dsos are NOT getting the DT_INIT/DT_FINI dynamic tags

Consider glibc test dlfcn/tstatexit, which uses a dso modatexit.so

In good case

| arc-linux-readelf -a modatexit.os
|
| Section Headers:
|  [Nr] Name              Type            Addr     Off    Size   ES Flg Lk Inf Al
|  [ 9] .init             PROGBITS        0000047c 00047c 000044 00  AX  0   0  4
|  [12] .fini             PROGBITS        000006f8 0006f8 000028 00  AX  0   0  4
|
| Dynamic section at offset 0x1f08 contains 23 entries:
|  0x0000000c (INIT)                       0x47c
|  0x0000000d (FINI)                       0x6f8

In broken case, init/fini sections exist,  but DT_INI/DT_FINI are missing.

|
| Dynamic section at offset 0x1f2c contains 19 entries: <-- missing INIT/FINI
|


I suspected some bintuils/gcc shenanigans and tried hacking around, but was led
far too astray.


(1). gcc config test failing (false alaram)

| host-gcc-final-ab544139bfee/build/gcc/config.log
|
|configure:22941: checking for .preinit_array/.init_array/.fini_array support
|configure:23106: checking cross compile... guessing
|configure:23111: result: no

gcc was seemingly built w/o init_array support leading to inclusion of default
gcc/config/initfini-array.h
However doing a glibc aarch64 build I see the same output so perhaps it is not
relevant.

(2). ARC binutils port seems to hardwire _init/_fini (and the only arch to do
that) so I ripped out the relevant handling from ld, but that doesn't help.


https://github.com/foss-for-synopsys-dwc-arc-processors/binutils-gdb/commit/56771171fa7cb9e31c65e26a656a8588d603d924


So I'm not sure if this is deficiency of linker emulation script or code ld/bfd etc..

-Vineet
Joseph Myers Jan. 28, 2019, 11:13 p.m. | #7
On Mon, 28 Jan 2019, Vineet Gupta wrote:

> In the failing case, the dsos are NOT getting the DT_INIT/DT_FINI 

> dynamic tags


And they shouldn't be (they should have DT_INIT_ARRAY / DT_FINI_ARRAY 
instead).

> (1). gcc config test failing (false alaram)

> 

> | host-gcc-final-ab544139bfee/build/gcc/config.log

> |

> |configure:22941: checking for .preinit_array/.init_array/.fini_array support

> |configure:23106: checking cross compile... guessing

> |configure:23111: result: no

> 

> gcc was seemingly built w/o init_array support leading to inclusion of default

> gcc/config/initfini-array.h

> However doing a glibc aarch64 build I see the same output so perhaps it is not

> relevant.


This was discussed at length in the C-Sky discussion.  In short: the 
proper fix is to change that configure test to apply for cross compilation 
as well, other than in the very limited case where it tries to run 
something (but doing so is not appropriate in the current 
regression-fixes-only GCC development stage).  You can hack around it with 
gcc_cv_initfini_array=yes for the target in config.gcc, as done by a few 
architectures.  Or you can define the relevant target macros in 
gcc/config/<arch>/<something>.h to force init_array / fini_array use 
independent of the configure test, as done for AArch64.

-- 
Joseph S. Myers
joseph@codesourcery.com
Vineet Gupta Jan. 28, 2019, 11:42 p.m. | #8
On 1/28/19 3:13 PM, Joseph Myers wrote:
> This was discussed at length in the C-Sky discussion.  In short: the 
> proper fix is to change that configure test to apply for cross compilation 
> as well, other than in the very limited case where it tries to run 
> something (but doing so is not appropriate in the current 
> regression-fixes-only GCC development stage).  You can hack around it with 
> gcc_cv_initfini_array=yes for the target in config.gcc, as done by a few 
> architectures.  Or you can define the relevant target macros in 
> gcc/config/<arch>/<something>.h to force init_array / fini_array use 
> independent of the configure test, as done for AArch64.

Awesome, now I see how it was working for RISCV (config test printed "cached") and
AArch64
I've added a local hack to gcc.config to test things out and will tackle this over
at gcc mailing list.

Many thx for untangling this for me. I found the C-Sky discussion as well [1]
adding a link here for someone else in future who trips on this again.

-Vineet

[1] https://sourceware.org/ml/libc-alpha/2018-11/msg00870.html

Patch

diff --git a/ChangeLog b/ChangeLog
index 3ec6eb82d2fe..c2efdafa9861 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -4,6 +4,26 @@ 
 	syscall-template file.
 	* stdlib/longlong.h: Fix asm constraints for ARC code.
 	* elf/elf.h: add defines for ARC.
+	* sysdeps/arc/__longjmp.S: New file.
+	* sysdeps/arc/abort-instr.h: New file.
+	* sysdeps/arc/bits/endian.h: New file.
+	* sysdeps/arc/bits/setjmp.h: New file.
+	* sysdeps/arc/bsd-_setjmp.S: New file.
+	* sysdeps/arc/bsd-setjmp.S: New file.
+	* sysdeps/arc/crti.S: New file.
+	* sysdeps/arc/crtn.S: New file.
+	* sysdeps/arc/dl-runtime.c: New file.
+	* sysdeps/arc/dl-sysdep.h: New file.
+	* sysdeps/arc/dl-trampoline.S: New file.
+	* sysdeps/arc/gccframe.h: New file.
+	* sysdeps/arc/gmp-mparam.h: New file.
+	* sysdeps/arc/jmpbuf-offsets.h: New file.
+	* sysdeps/arc/jmpbuf-unwind.h: New file.
+	* sysdeps/arc/machine-gmon.h: New file.
+	* sysdeps/arc/memusage.h: New file.
+	* sysdeps/arc/setjmp.S: New file.
+	* sysdeps/arc/sysdep.h: New file.
+	* sysdeps/arc/tls-macros.h: New file.
 
 2018-12-17  Joseph Myers  <joseph@codesourcery.com>
 
diff --git a/sysdeps/arc/__longjmp.S b/sysdeps/arc/__longjmp.S
new file mode 100644
index 000000000000..5ef271536bcc
--- /dev/null
+++ b/sysdeps/arc/__longjmp.S
@@ -0,0 +1,50 @@ 
+/* longjmp for ARC.
+   Copyright (C) 2017-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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 <jmpbuf-offsets.h>
+
+;@ r0 = jump buffer from which regs will be restored
+;@ r1 = value that setjmp( ) will return due to this longjmp
+
+ENTRY(__longjmp)
+
+	ld_s r13,   [r0]
+	ld_s r14,   [r0,4]
+	ld   r15,   [r0,8]
+	ld   r16,   [r0,12]
+	ld   r17,   [r0,16]
+	ld   r18,   [r0,20]
+	ld   r19,   [r0,24]
+	ld   r20,   [r0,28]
+	ld   r21,   [r0,32]
+	ld   r22,   [r0,36]
+	ld   r23,   [r0,40]
+	ld   r24,   [r0,44]
+	ld   r25,   [r0,48]
+
+	ld   blink, [r0,60]
+	ld   fp,    [r0,52]
+	ld   sp,    [r0,56]
+
+	mov.f  r0, r1	; get the setjmp return value(due to longjmp) in place
+
+	j.d    [blink]	; to caller of setjmp location, right after the call
+	mov.z  r0, 1	; can't let setjmp return 0 when it is due to longjmp
+
+END(__longjmp)
diff --git a/sysdeps/arc/abort-instr.h b/sysdeps/arc/abort-instr.h
new file mode 100644
index 000000000000..474098e9a819
--- /dev/null
+++ b/sysdeps/arc/abort-instr.h
@@ -0,0 +1,2 @@ 
+/* FLAG 1 is privilege mode only instruction, hence will crash any program */
+#define ABORT_INSTRUCTION asm ("flag 1")
diff --git a/sysdeps/arc/bits/endian.h b/sysdeps/arc/bits/endian.h
new file mode 100644
index 000000000000..88fbcf39a58a
--- /dev/null
+++ b/sysdeps/arc/bits/endian.h
@@ -0,0 +1,12 @@ 
+/* The ARC architecture has selectable endianness.  */
+
+#ifndef _ENDIAN_H
+# error "Never use <bits/endian.h> directly; include <endian.h> instead."
+#endif
+
+#ifdef __BIG_ENDIAN__
+# define __BYTE_ORDER __BIG_ENDIAN
+#endif
+#ifdef __LITTLE_ENDIAN__
+# define __BYTE_ORDER __LITTLE_ENDIAN
+#endif
diff --git a/sysdeps/arc/bits/setjmp.h b/sysdeps/arc/bits/setjmp.h
new file mode 100644
index 000000000000..3a014955ee5a
--- /dev/null
+++ b/sysdeps/arc/bits/setjmp.h
@@ -0,0 +1,33 @@ 
+/* Define the machine-dependent type `jmp_buf'.  ARC version.
+   Copyright (C) 1992-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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/>.  */
+
+#ifndef _BITS_SETJMP_H
+#define _BITS_SETJMP_H 1
+
+#if !defined(_SETJMP_H) && !defined(_PTHREAD_H)
+# error "Never include <bits/setjmp.h> directly; use <setjmp.h> instead."
+#endif
+
+#ifndef __ASSEMBLER__
+
+/* Saves r13-r25 (callee-saved), fp (frame pointer), sp (stack pointer),
+ * blink (branch-n-link) */
+typedef int __jmp_buf[32];
+#endif
+
+#endif
diff --git a/sysdeps/arc/bsd-_setjmp.S b/sysdeps/arc/bsd-_setjmp.S
new file mode 100644
index 000000000000..4e6a2da560c4
--- /dev/null
+++ b/sysdeps/arc/bsd-_setjmp.S
@@ -0,0 +1 @@ 
+/* _setjmp is in setjmp.S  */
diff --git a/sysdeps/arc/bsd-setjmp.S b/sysdeps/arc/bsd-setjmp.S
new file mode 100644
index 000000000000..1da848d2f1ee
--- /dev/null
+++ b/sysdeps/arc/bsd-setjmp.S
@@ -0,0 +1 @@ 
+/* setjmp is in setjmp.S  */
diff --git a/sysdeps/arc/crti.S b/sysdeps/arc/crti.S
new file mode 100644
index 000000000000..8b823b54a29d
--- /dev/null
+++ b/sysdeps/arc/crti.S
@@ -0,0 +1,77 @@ 
+/* Special .init and .fini section support for ARC.
+   Copyright (C) 2012-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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.
+
+   In addition to the permissions in the GNU Lesser General Public
+   License, the Free Software Foundation gives you unlimited
+   permission to link the compiled version of this file with other
+   programs, and to distribute those programs without any restriction
+   coming from the use of this file. (The GNU Lesser General Public
+   License restrictions do apply in other respects; for example, they
+   cover modification of the file, and distribution when not linked
+   into another program.)
+
+   Note that people who make modified versions of this file are not
+   obligated to grant this special exception for their modified
+   versions; it is their choice whether to do so. The GNU Lesser
+   General Public License gives permission to release a modified
+   version without this exception; this exception also makes it
+   possible to release a modified version which carries forward this
+   exception.
+
+   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 <libc-symbols.h>
+#include <sysdep.h>
+
+#ifndef PREINIT_FUNCTION
+# define PREINIT_FUNCTION __gmon_start__
+#endif
+
+#ifndef PREINIT_FUNCTION_WEAK
+# define PREINIT_FUNCTION_WEAK 1
+#endif
+
+#if PREINIT_FUNCTION_WEAK
+	weak_extern (PREINIT_FUNCTION)
+#else
+	.hidden PREINIT_FUNCTION
+#endif
+
+	.section .init
+	.align 4
+	.global	_init
+	.type	 _init,@function
+_init:
+	st.a	blink, [sp,-4]
+	st.a	fp, [sp,-4]
+	mov	fp, sp
+#if PREINIT_FUNCTION_WEAK
+	ld	r0, [pcl, @PREINIT_FUNCTION@gotpc]
+	tst	r0, r0
+	jlnz	[r0]
+#else
+	bl	PREINIT_FUNCTION
+#endif
+
+	.section .fini
+	.align 4
+	.global	_fini
+	.type	 _fini,@function
+_fini:
+	st.a blink,[sp,-4]
+	st.a fp,[sp,-4]
+	mov fp,sp
+	.align 4
diff --git a/sysdeps/arc/crtn.S b/sysdeps/arc/crtn.S
new file mode 100644
index 000000000000..c6c58c5593c9
--- /dev/null
+++ b/sysdeps/arc/crtn.S
@@ -0,0 +1,56 @@ 
+/* Special .init and .fini section support for ARC.
+   Copyright (C) 2012-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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.
+
+   In addition to the permissions in the GNU Lesser General Public
+   License, the Free Software Foundation gives you unlimited
+   permission to link the compiled version of this file with other
+   programs, and to distribute those programs without any restriction
+   coming from the use of this file. (The GNU Lesser General Public
+   License restrictions do apply in other respects; for example, they
+   cover modification of the file, and distribution when not linked
+   into another program.)
+
+   Note that people who make modified versions of this file are not
+   obligated to grant this special exception for their modified
+   versions; it is their choice whether to do so. The GNU Lesser
+   General Public License gives permission to release a modified
+   version without this exception; this exception also makes it
+   possible to release a modified version which carries forward this
+   exception.
+
+   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/>.  */
+
+	.section .init
+	.align 4
+	.global	_init
+	.type	 _init,@function
+	; EPILOGUE
+	ld.ab fp,[sp,4]
+	ld blink,[sp,0]
+	j.d [blink]
+	add sp,sp,4
+;	.size	 _init,.-_init
+
+	.section .fini
+	.align 4
+	.global	_fini
+	.type	 _fini,@function
+	; EPILOGUE
+	ld.ab fp,[sp,4]
+	ld blink,[sp,0]
+	j.d [blink]
+	add sp,sp,4
+;	.size	 _fini,.-_fini
diff --git a/sysdeps/arc/dl-runtime.c b/sysdeps/arc/dl-runtime.c
new file mode 100644
index 000000000000..76d39fab5ab8
--- /dev/null
+++ b/sysdeps/arc/dl-runtime.c
@@ -0,0 +1,21 @@ 
+/* PLT jump into resolver passes PC of PLTn, while _dl_fixup expects the
+   address of corresponding .rela.plt entry */
+
+#ifdef __A7__
+#define ARC_PLT_SIZE	12
+#else
+#define ARC_PLT_SIZE	16
+#endif
+
+#define reloc_index					\
+({							\
+  unsigned long plt0 = D_PTR (l, l_info[DT_PLTGOT]);	\
+  unsigned long pltn = reloc_arg;			\
+  /* exclude PL0 and PLT1 */				\
+  unsigned long idx = (pltn - plt0)/ARC_PLT_SIZE - 2;	\
+  idx;							\
+})
+
+#define reloc_offset reloc_index * sizeof (PLTREL)
+
+#include <elf/dl-runtime.c>
diff --git a/sysdeps/arc/dl-sysdep.h b/sysdeps/arc/dl-sysdep.h
new file mode 100644
index 000000000000..a3e734c1020c
--- /dev/null
+++ b/sysdeps/arc/dl-sysdep.h
@@ -0,0 +1,25 @@ 
+/* System-specific settings for dynamic linker code.  ARC version.
+   Copyright (C) 2009-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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_next <dl-sysdep.h>
+
+/* _dl_argv cannot be attribute_relro, because _dl_start_user
+   might write into it after _dl_start returns.  */
+#define DL_ARGV_NOT_RELRO 1
+
+#define DL_EXTERN_PROTECTED_DATA
diff --git a/sysdeps/arc/dl-trampoline.S b/sysdeps/arc/dl-trampoline.S
new file mode 100644
index 000000000000..c704f0ff9a95
--- /dev/null
+++ b/sysdeps/arc/dl-trampoline.S
@@ -0,0 +1,72 @@ 
+/* PLT trampolines.  ARC version.
+   Copyright (C) 2005-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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 <libc-symbols.h>
+
+#include <sysdep.h>
+#include <sys/syscall.h>
+
+; Save the registers which resolver could possibly clobber
+; 	r0-r9: args to the function - symbol being resolved
+; 	r10-r12 are already clobbered by PLTn, PLT0 thus neednot be saved
+
+.macro	SAVE_CALLER_SAVED
+	push_s	r0
+	push_s	r1
+	push_s	r2
+	push_s	r3
+	st.a	r4, [sp, -4]
+	st.a	r5, [sp, -4]
+	st.a	r6, [sp, -4]
+	st.a	r7, [sp, -4]
+	st.a	r8, [sp, -4]
+	st.a	r9, [sp, -4]
+	push_s	blink
+.endm
+
+.macro RESTORE_CALLER_SAVED_BUT_R0
+	ld.ab	blink,[sp, 4]
+	ld.ab	r9, [sp, 4]
+	ld.ab	r8, [sp, 4]
+	ld.ab	r7, [sp, 4]
+	ld.ab	r6, [sp, 4]
+	ld.ab	r5, [sp, 4]
+	ld.ab	r4, [sp, 4]
+	pop_s   r3
+	pop_s   r2
+	pop_s   r1
+.endm
+
+; Upon entry, PLTn, which led us here, sets up the following regs
+; 	r11 = Module info (tpnt pointer as expected by resolver)
+;	r12 = PC of the PLTn itself - needed by resolver to find
+;	      corresponding .rela.plt entry
+
+ENTRY(_dl_runtime_resolve)
+	; args to func being resolved, which resolver might clobber
+	SAVE_CALLER_SAVED
+
+	mov_s 	r1, r12
+	bl.d  	_dl_fixup
+	mov   	r0, r11
+
+	RESTORE_CALLER_SAVED_BUT_R0
+	j_s.d   [r0]    ; r0 has resolved function addr
+	pop_s   r0      ; restore first arg to resolved call
+END(_dl_runtime_resolve)
diff --git a/sysdeps/arc/gccframe.h b/sysdeps/arc/gccframe.h
new file mode 100644
index 000000000000..54a1225284b6
--- /dev/null
+++ b/sysdeps/arc/gccframe.h
@@ -0,0 +1,21 @@ 
+/* Definition of object in frame unwind info.  ARC version.
+   Copyright (C) 2017-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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/>.  */
+
+#define FIRST_PSEUDO_REGISTER 40
+
+#include <sysdeps/generic/gccframe.h>
diff --git a/sysdeps/arc/gmp-mparam.h b/sysdeps/arc/gmp-mparam.h
new file mode 100644
index 000000000000..2b09517766e3
--- /dev/null
+++ b/sysdeps/arc/gmp-mparam.h
@@ -0,0 +1,23 @@ 
+/* gmp-mparam.h -- Compiler/machine parameter header file.
+
+Copyright (C) 2017-2018 Free Software Foundation, Inc.
+
+This file is part of the GNU MP Library.
+
+The GNU MP 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 MP 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 MP Library; see the file COPYING.LIB.  If not, see
+<http://www.gnu.org/licenses/>.  */
+
+#include <sysdeps/generic/gmp-mparam.h>
+
+#define IEEE_DOUBLE_BIG_ENDIAN 0
diff --git a/sysdeps/arc/jmpbuf-offsets.h b/sysdeps/arc/jmpbuf-offsets.h
new file mode 100644
index 000000000000..c9cf4bc2e355
--- /dev/null
+++ b/sysdeps/arc/jmpbuf-offsets.h
@@ -0,0 +1,46 @@ 
+/* Private macros for accessing __jmp_buf contents.  ARC version.
+   Copyright (C) 2006-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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/>.  */
+
+/* Save offsets within __jmp_buf.  */
+/* We don't use most of these symbols; they are here for documentation. */
+
+/* Callee Regs */
+#define JB_R13 0
+#define JB_R14 1
+#define JB_R15 2
+#define JB_R16 3
+#define JB_R17 4
+#define JB_R18 5
+#define JB_R19 6
+#define JB_R20 7
+#define JB_R21 8
+#define JB_R22 9
+#define JB_R23 10
+#define JB_R24 11
+#define JB_R25 12
+
+/* Frame Pointer, Stack Pointer, Branch-n-link */
+#define JB_FP  13
+#define JB_SP  14
+#define JB_BLINK  15
+
+/* We save space for some extra state to accommodate future changes.  */
+#define JB_NUM	32	/* words */
+
+/* Helper for generic ____longjmp_chk(). */
+#define JB_FRAME_ADDRESS(buf) ((void *) (unsigned long) (buf[JB_SP]))
diff --git a/sysdeps/arc/jmpbuf-unwind.h b/sysdeps/arc/jmpbuf-unwind.h
new file mode 100644
index 000000000000..d87ac13b3416
--- /dev/null
+++ b/sysdeps/arc/jmpbuf-unwind.h
@@ -0,0 +1,47 @@ 
+/* Examine __jmp_buf for unwinding frames.  ARC version.
+   Copyright (C) 2005-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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 <setjmp.h>
+#include <jmpbuf-offsets.h>
+#include <stdint.h>
+#include <unwind.h>
+
+/* Test if longjmp to JMPBUF would unwind the frame
+   containing a local variable at ADDRESS.  */
+
+#define _JMPBUF_UNWINDS(jmpbuf, address, demangle) \
+  ((void *) (address) < (void *) demangle (jmpbuf[JB_SP]))
+
+#define _JMPBUF_CFA_UNWINDS_ADJ(_jmpbuf, _context, _adj) \
+  _JMPBUF_UNWINDS_ADJ (_jmpbuf, (void *) _Unwind_GetCFA (_context), _adj)
+
+static inline uintptr_t __attribute__ ((unused))
+_jmpbuf_sp (__jmp_buf jmpbuf)
+{
+  uintptr_t sp = jmpbuf[JB_SP];
+#ifdef PTR_DEMANGLE
+  PTR_DEMANGLE (sp);
+#endif
+  return sp;
+}
+
+#define _JMPBUF_UNWINDS_ADJ(_jmpbuf, _address, _adj) \
+  ((uintptr_t) (_address) - (_adj) < (uintptr_t) (_jmpbuf_sp (_jmpbuf) - (_adj)))
+
+/* We use the normal longjmp for unwinding.  */
+#define __libc_unwind_longjmp(buf, val) __libc_longjmp (buf, val)
diff --git a/sysdeps/arc/machine-gmon.h b/sysdeps/arc/machine-gmon.h
new file mode 100644
index 000000000000..55facf77a858
--- /dev/null
+++ b/sysdeps/arc/machine-gmon.h
@@ -0,0 +1,33 @@ 
+/* Machine-dependent definitions for profiling support.  ARC version.
+   Copyright (C) 1996-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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>
+
+#define _MCOUNT_DECL(frompc, selfpc)
+static void __mcount_internal (unsigned long frompc, unsigned long selfpc)
+
+/* this is very simple as gcc does all the heavy lifting at _mcount call site
+ *  - sets up caller's blink in r0, so frompc is setup correctly
+ *  - preserve argument registers for original call */
+
+#define MCOUNT								\
+void _mcount (void *frompc)						\
+{									\
+  __mcount_internal ((unsigned long int) frompc,				\
+		   (unsigned long int) __builtin_return_address(0));	\
+}
diff --git a/sysdeps/arc/memusage.h b/sysdeps/arc/memusage.h
new file mode 100644
index 000000000000..536f1fdbf614
--- /dev/null
+++ b/sysdeps/arc/memusage.h
@@ -0,0 +1,23 @@ 
+/* Machine-specific definitions for memory usage profiling, ARC version.
+   Copyright (C) 2000-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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/>.  */
+
+#define GETSP() ({ register uintptr_t stack_ptr asm ("sp"); stack_ptr; })
+
+#define uatomic32_t unsigned int
+
+#include <sysdeps/generic/memusage.h>
diff --git a/sysdeps/arc/setjmp.S b/sysdeps/arc/setjmp.S
new file mode 100644
index 000000000000..cbd44e538339
--- /dev/null
+++ b/sysdeps/arc/setjmp.S
@@ -0,0 +1,64 @@ 
+/* setjmp for ARC.
+   Copyright (C) 1991-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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>
+
+;@ r0 = jump buffer into which regs will be saved
+ENTRY(setjmp)
+	b.d	__sigsetjmp
+	mov	r1, 1		; save signals
+END(setjmp)
+
+;@ r0 = jump buffer into which regs will be saved
+ENTRY(_setjmp)
+	b.d	__sigsetjmp
+	mov	r1, 0		; don't save signals
+END(_setjmp)
+libc_hidden_def(_setjmp)
+
+;@ r0 = jump buffer into which regs will be saved
+;@ r1 = do we need to save signals
+ENTRY(__sigsetjmp)
+
+	st_s r13, [r0]
+	st_s r14, [r0,4]
+	st   r15, [r0,8]
+	st   r16, [r0,12]
+	st   r17, [r0,16]
+	st   r18, [r0,20]
+	st   r19, [r0,24]
+	st   r20, [r0,28]
+	st   r21, [r0,32]
+	st   r22, [r0,36]
+	st   r23, [r0,40]
+	st   r24, [r0,44]
+	st   r25, [r0,48]
+	st   fp,  [r0,52]
+	st   sp,  [r0,56]
+
+	; make a note of where longjmp will return to.
+	; that will be right next to this setjmp call-site which will be
+	; contained in blink, since "C" caller of this routine will do
+	; a branch-n-link
+
+	st   blink, [r0,60]
+	b    __sigjmp_save
+
+END(__sigsetjmp)
+libc_hidden_def(__sigsetjmp)
diff --git a/sysdeps/arc/sysdep.h b/sysdeps/arc/sysdep.h
new file mode 100644
index 000000000000..5c6e063d03fe
--- /dev/null
+++ b/sysdeps/arc/sysdep.h
@@ -0,0 +1,49 @@ 
+/* Assembler macros for ARC.
+   Copyright (C) 2017-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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 <sysdeps/generic/sysdep.h>
+
+#ifdef	__ASSEMBLER__
+
+/* Syntactic details of assembler.
+ * One weirness is ; is not newline but comment
+ * Although # is also for comment
+ */
+
+#define ASM_SIZE_DIRECTIVE(name) .size name,.-name
+
+#define ENTRY(name)						\
+    .align 4					ASM_LINE_SEP	\
+    .globl C_SYMBOL_NAME(name)			ASM_LINE_SEP	\
+    .type C_SYMBOL_NAME(name),%function		ASM_LINE_SEP	\
+  C_LABEL(name)					ASM_LINE_SEP	\
+    CALL_MCOUNT
+
+#undef  END
+#define END(name)						\
+  ASM_SIZE_DIRECTIVE(name)
+
+#ifdef SHARED
+#define PLTJMP(_x)	_x##@plt
+#else
+#define PLTJMP(_x)	_x
+#endif
+
+# define CALL_MCOUNT		/* Do nothing for now.  */
+
+#endif	/* __ASSEMBLER__ */
diff --git a/sysdeps/arc/tls-macros.h b/sysdeps/arc/tls-macros.h
new file mode 100644
index 000000000000..51855edef6e7
--- /dev/null
+++ b/sysdeps/arc/tls-macros.h
@@ -0,0 +1,29 @@ 
+/* Macros to support TLS testing in times of missing compiler support.  */
+
+/* For now */
+#define TLS_LD(x)	TLS_IE(x)
+
+#define TLS_GD(x)					\
+  ({ int *__result;					\
+     __asm__ ("add r0, pcl, @" #x "@tlsgd      \n"     	\
+	  ".tls_gd_ld " #x "`bl __tls_get_addr@plt \n"	\
+	  "mov %0, r0                    \n"		\
+	  : "=&r" (__result)				\
+	  ::"r0","r1","r2","r3","r4","r5","r6","r7",	\
+	    "r8","r9","r10","r11","r12");		\
+     __result; })
+
+#define TLS_LE(x)					\
+  ({ int *__result;					\
+     void *tp = __builtin_thread_pointer();		\
+     __asm__ ("add %0, %1, @" #x "@tpoff   \n"		\
+	  : "=r" (__result) : "r"(tp));	        	\
+     __result; })
+
+#define TLS_IE(x)					\
+  ({ int *__result;					\
+     void *tp = __builtin_thread_pointer();		\
+     __asm__ ("ld %0, [pcl, @" #x "@tlsie]      \n"     \
+	  "add %0, %1, %0                       \n"	\
+	  : "=&r" (__result) : "r" (tp));		\
+     __result; })