[v2,MSP430] Add msp430-elfbare target

Message ID 20191129210007.21eaa10d@jozef-kubuntu
State New
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  • [v2,MSP430] Add msp430-elfbare target
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Commit Message

Jozef Lawrynowicz Nov. 29, 2019, 9 p.m.
The attached patch consolidates some configuration tweaks I previously submitted
as modifications to the msp430-elf target into a new target called
"msp430-elfbare" i.e. "bare-metal".

MSP430: Disable TM clone registry by default
  https://gcc.gnu.org/ml/gcc-patches/2019-11/msg00550.html
MSP430: Disable __cxa_atexit
  https://gcc.gnu.org/ml/gcc-patches/2019-11/msg00552.html

The patches tweak the CRT code to achieve the smallest possible code size, 
and rely on some additional generic tweaks to crtstuff.c.

I did submit these tweaks a while ago, but I didn't get any feedback,
however even if they are acceptable I suspect it is too late for GCC-10 anyway:
libgcc: Dont define __do_global_dtors_aux if it will be empty
  https://gcc.gnu.org/ml/gcc-patches/2019-11/msg00417.html
libgcc: Implement TARGET_LIBGCC_REMOVE_DSO_HANDLE
  https://gcc.gnu.org/ml/gcc-patches/2019-11/msg00418.html

(The second one is a bit hacky, but without some way of removing the
__dso_handle declaration, we end up with 150 bytes of unnecessary code in some
programs.)

So for this patch crtstuff.c was copied to the msp430 subdirectory and the
changes were made to that target specific version.

Tiny program size can now be achieved by configuring gcc for msp430-elfbare.

For example in an "empty main" program which loops forever:
  msp430-elfbare @ -Os:
     text    data     bss     dec     hex filename
       14       0       0      14       e a.out
  msp430-elf @ -Os:
     text    data     bss     dec     hex filename
      270       6       2     278     116 a.out

Successfully regtested msp430-elfbare vs msp430-elf.

Ok to apply?

P.S. This patch relies on the -fno-exceptions multilib patch submitted here:
https://gcc.gnu.org/ml/gcc-patches/2019-11/msg02523.html

P.P.S. This requires some minor configury tweaks to Newlib and GDB of the form:
-  msp430*-*-elf)
+  msp430-*-elf*)
I'll apply these changes if the patch is accepted.

Comments

Jeff Law Dec. 7, 2019, 6:40 p.m. | #1
On Fri, 2019-11-29 at 21:00 +0000, Jozef Lawrynowicz wrote:
> The attached patch consolidates some configuration tweaks I

> previously submitted

> as modifications to the msp430-elf target into a new target called

> "msp430-elfbare" i.e. "bare-metal".

> 

> MSP430: Disable TM clone registry by default

>   https://gcc.gnu.org/ml/gcc-patches/2019-11/msg00550.html

> MSP430: Disable __cxa_atexit

>   https://gcc.gnu.org/ml/gcc-patches/2019-11/msg00552.html

> 

> The patches tweak the CRT code to achieve the smallest possible code

> size, 

> and rely on some additional generic tweaks to crtstuff.c.

> 

> I did submit these tweaks a while ago, but I didn't get any feedback,

> however even if they are acceptable I suspect it is too late for GCC-

> 10 anyway:

> libgcc: Dont define __do_global_dtors_aux if it will be empty

>   https://gcc.gnu.org/ml/gcc-patches/2019-11/msg00417.html

> libgcc: Implement TARGET_LIBGCC_REMOVE_DSO_HANDLE

>   https://gcc.gnu.org/ml/gcc-patches/2019-11/msg00418.html

> 

> (The second one is a bit hacky, but without some way of removing the

> __dso_handle declaration, we end up with 150 bytes of unnecessary

> code in some

> programs.)

> 

> So for this patch crtstuff.c was copied to the msp430 subdirectory

> and the

> changes were made to that target specific version.

> 

> Tiny program size can now be achieved by configuring gcc for msp430-

> elfbare.

> 

> For example in an "empty main" program which loops forever:

>   msp430-elfbare @ -Os:

>      text    data     bss     dec     hex filename

>        14       0       0      14       e a.out

>   msp430-elf @ -Os:

>      text    data     bss     dec     hex filename

>       270       6       2     278     116 a.out

> 

> Successfully regtested msp430-elfbare vs msp430-elf.

> 

> Ok to apply?

> 

> P.S. This patch relies on the -fno-exceptions multilib patch

> submitted here:

> https://gcc.gnu.org/ml/gcc-patches/2019-11/msg02523.html

> 

> P.P.S. This requires some minor configury tweaks to Newlib and GDB of

> the form:

> -  msp430*-*-elf)

> +  msp430-*-elf*)


> I'll apply these changes if the patch is accepted.

> From cff4611855d838315e793d45256de5fc8eeefafe Mon Sep 17 00:00:00

> 2001

> From: Jozef Lawrynowicz <jozef.l@mittosystems.com>

> Date: Mon, 25 Nov 2019 19:41:05 +0000

> Subject: [PATCH] MSP430: Add new msp430-elfbare target

> 

> contrib/ChangeLog:

> 

> 2019-11-29  Jozef Lawrynowicz  <jozef.l@mittosystems.com>

> 

> 	* config-list.mk: Add msp430-elfbare.

> 

> gcc/ChangeLog:

> 

> 2019-11-29  Jozef Lawrynowicz  <jozef.l@mittosystems.com>

> 

> 	* config.gcc: s/msp430*-*-*/msp430-*-*.

> 	Handle msp430-*-elfbare.

> 	* config/msp430/msp430-devices.c (TARGET_SUBDIR): Define.

> 	(_MSPMKSTR): Define.

> 	(__MSPMKSTR): Define.

> 	(rest_of_devices_path): Use TARGET_SUBDIR value in string.

> 	* config/msp430/msp430.c (msp430_option_override): Error if

> 	-fuse-cxa-atexit is used when it has been disabled at configure

> time.

> 	* config/msp430/t-msp430: Define TARGET_SUBDIR when building

> 	msp430-devices.o.

> 	* doc/install.texi: Document msp430-*-elf and msp430-*-elfbare.

> 	* doc/invoke.texi: Update documentation about which path

> devices.csv is

> 	searched for.

> 

> gcc/testsuite/ChangeLog:

> 

> 2019-11-29  Jozef Lawrynowicz  <jozef.l@mittosystems.com>

> 

> 	* g++.dg/init/dso_handle1.C: Require cxa_atexit support.

> 	* g++.dg/init/dso_handle2.C: Likewise.

> 	* g++.dg/other/cxa-atexit1.C: Likewise.

> 	* gcc.target/msp430/msp430.exp: Update csv-using-installed.c

> test to

> 	handle msp430-elfbare configuration.

> 

> libgcc/ChangeLog:

> 

> 2019-11-29  Jozef Lawrynowicz  <jozef.l@mittosystems.com>

> 

> 	* config.host: Use t-msp430-elfbare-crtstuff Makefile fragment

> when GCC

> 	is configured for the msp430-elfbare target.

> 	* config/msp430/msp430-elfbare-crtstuff.c: New file.

> 	* config/msp430/t-msp430: Remove Makefile rules for object

> files

> 	built from crtstuff.c

> 	* config/msp430/t-msp430-crtstuff: New file.

> 	* config/msp430/t-msp430-elfbare-crtstuff: New file.

> 	* configure: Regenerate.

> 	* configure.ac: Disable TM clone registry by default for

> 	msp430-elfbare.

OK.   I probably would have tried to avoid msp430-elfbare-crtstuff, but
it's not a huge wart IMHO.

Jeff
>
Jozef Lawrynowicz Dec. 9, 2019, 3:28 p.m. | #2
On Sat, 07 Dec 2019 11:40:33 -0700
Jeff Law <law@redhat.com> wrote:

> On Fri, 2019-11-29 at 21:00 +0000, Jozef Lawrynowicz wrote:

> > The attached patch consolidates some configuration tweaks I

> > previously submitted

> > as modifications to the msp430-elf target into a new target called

> > "msp430-elfbare" i.e. "bare-metal".

> > 

> > MSP430: Disable TM clone registry by default

> >   https://gcc.gnu.org/ml/gcc-patches/2019-11/msg00550.html

> > MSP430: Disable __cxa_atexit

> >   https://gcc.gnu.org/ml/gcc-patches/2019-11/msg00552.html

> > 

> > The patches tweak the CRT code to achieve the smallest possible code

> > size, 

> > and rely on some additional generic tweaks to crtstuff.c.

> > 

> > I did submit these tweaks a while ago, but I didn't get any feedback,

> > however even if they are acceptable I suspect it is too late for GCC-

> > 10 anyway:

> > libgcc: Dont define __do_global_dtors_aux if it will be empty

> >   https://gcc.gnu.org/ml/gcc-patches/2019-11/msg00417.html

> > libgcc: Implement TARGET_LIBGCC_REMOVE_DSO_HANDLE

> >   https://gcc.gnu.org/ml/gcc-patches/2019-11/msg00418.html

> > 

> > (The second one is a bit hacky, but without some way of removing the

> > __dso_handle declaration, we end up with 150 bytes of unnecessary

> > code in some

> > programs.)

> > 

> > So for this patch crtstuff.c was copied to the msp430 subdirectory

> > and the

> > changes were made to that target specific version.

> > 

> > Tiny program size can now be achieved by configuring gcc for msp430-

> > elfbare.

> > 

> > For example in an "empty main" program which loops forever:

> >   msp430-elfbare @ -Os:

> >      text    data     bss     dec     hex filename

> >        14       0       0      14       e a.out

> >   msp430-elf @ -Os:

> >      text    data     bss     dec     hex filename

> >       270       6       2     278     116 a.out

> > 

> > Successfully regtested msp430-elfbare vs msp430-elf.

> > 

> > Ok to apply?

> > 

> > P.S. This patch relies on the -fno-exceptions multilib patch

> > submitted here:

> > https://gcc.gnu.org/ml/gcc-patches/2019-11/msg02523.html

> > 

> > P.P.S. This requires some minor configury tweaks to Newlib and GDB of

> > the form:

> > -  msp430*-*-elf)

> > +  msp430-*-elf*)  

> 

> > I'll apply these changes if the patch is accepted.

> > From cff4611855d838315e793d45256de5fc8eeefafe Mon Sep 17 00:00:00

> > 2001

> > From: Jozef Lawrynowicz <jozef.l@mittosystems.com>

> > Date: Mon, 25 Nov 2019 19:41:05 +0000

> > Subject: [PATCH] MSP430: Add new msp430-elfbare target

> > 

> > contrib/ChangeLog:

> > 

> > 2019-11-29  Jozef Lawrynowicz  <jozef.l@mittosystems.com>

> > 

> > 	* config-list.mk: Add msp430-elfbare.

> > 

> > gcc/ChangeLog:

> > 

> > 2019-11-29  Jozef Lawrynowicz  <jozef.l@mittosystems.com>

> > 

> > 	* config.gcc: s/msp430*-*-*/msp430-*-*.

> > 	Handle msp430-*-elfbare.

> > 	* config/msp430/msp430-devices.c (TARGET_SUBDIR): Define.

> > 	(_MSPMKSTR): Define.

> > 	(__MSPMKSTR): Define.

> > 	(rest_of_devices_path): Use TARGET_SUBDIR value in string.

> > 	* config/msp430/msp430.c (msp430_option_override): Error if

> > 	-fuse-cxa-atexit is used when it has been disabled at configure

> > time.

> > 	* config/msp430/t-msp430: Define TARGET_SUBDIR when building

> > 	msp430-devices.o.

> > 	* doc/install.texi: Document msp430-*-elf and msp430-*-elfbare.

> > 	* doc/invoke.texi: Update documentation about which path

> > devices.csv is

> > 	searched for.

> > 

> > gcc/testsuite/ChangeLog:

> > 

> > 2019-11-29  Jozef Lawrynowicz  <jozef.l@mittosystems.com>

> > 

> > 	* g++.dg/init/dso_handle1.C: Require cxa_atexit support.

> > 	* g++.dg/init/dso_handle2.C: Likewise.

> > 	* g++.dg/other/cxa-atexit1.C: Likewise.

> > 	* gcc.target/msp430/msp430.exp: Update csv-using-installed.c

> > test to

> > 	handle msp430-elfbare configuration.

> > 

> > libgcc/ChangeLog:

> > 

> > 2019-11-29  Jozef Lawrynowicz  <jozef.l@mittosystems.com>

> > 

> > 	* config.host: Use t-msp430-elfbare-crtstuff Makefile fragment

> > when GCC

> > 	is configured for the msp430-elfbare target.

> > 	* config/msp430/msp430-elfbare-crtstuff.c: New file.

> > 	* config/msp430/t-msp430: Remove Makefile rules for object

> > files

> > 	built from crtstuff.c

> > 	* config/msp430/t-msp430-crtstuff: New file.

> > 	* config/msp430/t-msp430-elfbare-crtstuff: New file.

> > 	* configure: Regenerate.

> > 	* configure.ac: Disable TM clone registry by default for

> > 	msp430-elfbare.  

> OK.   I probably would have tried to avoid msp430-elfbare-crtstuff, but

> it's not a huge wart IMHO.


If we get the __dso_handle removal into the generic libgcc/crtstuff.c those
changes won't be necessary.

Did you get a chance to look at "Add -fno-exceptions multilib" -
https://gcc.gnu.org/ml/gcc-patches/2019-11/msg02523.html

It is the cumulative effect of these patches that gives the good code size
results, unfortunately without them all there isn't a significant code size
improvement.

Thanks,
Jozef
> 

> Jeff

> >   

>

Patch

From cff4611855d838315e793d45256de5fc8eeefafe Mon Sep 17 00:00:00 2001
From: Jozef Lawrynowicz <jozef.l@mittosystems.com>
Date: Mon, 25 Nov 2019 19:41:05 +0000
Subject: [PATCH] MSP430: Add new msp430-elfbare target

contrib/ChangeLog:

2019-11-29  Jozef Lawrynowicz  <jozef.l@mittosystems.com>

	* config-list.mk: Add msp430-elfbare.

gcc/ChangeLog:

2019-11-29  Jozef Lawrynowicz  <jozef.l@mittosystems.com>

	* config.gcc: s/msp430*-*-*/msp430-*-*.
	Handle msp430-*-elfbare.
	* config/msp430/msp430-devices.c (TARGET_SUBDIR): Define.
	(_MSPMKSTR): Define.
	(__MSPMKSTR): Define.
	(rest_of_devices_path): Use TARGET_SUBDIR value in string.
	* config/msp430/msp430.c (msp430_option_override): Error if
	-fuse-cxa-atexit is used when it has been disabled at configure time.
	* config/msp430/t-msp430: Define TARGET_SUBDIR when building
	msp430-devices.o.
	* doc/install.texi: Document msp430-*-elf and msp430-*-elfbare.
	* doc/invoke.texi: Update documentation about which path devices.csv is
	searched for.

gcc/testsuite/ChangeLog:

2019-11-29  Jozef Lawrynowicz  <jozef.l@mittosystems.com>

	* g++.dg/init/dso_handle1.C: Require cxa_atexit support.
	* g++.dg/init/dso_handle2.C: Likewise.
	* g++.dg/other/cxa-atexit1.C: Likewise.
	* gcc.target/msp430/msp430.exp: Update csv-using-installed.c test to
	handle msp430-elfbare configuration.

libgcc/ChangeLog:

2019-11-29  Jozef Lawrynowicz  <jozef.l@mittosystems.com>

	* config.host: Use t-msp430-elfbare-crtstuff Makefile fragment when GCC
	is configured for the msp430-elfbare target.
	* config/msp430/msp430-elfbare-crtstuff.c: New file.
	* config/msp430/t-msp430: Remove Makefile rules for object files
	built from crtstuff.c
	* config/msp430/t-msp430-crtstuff: New file.
	* config/msp430/t-msp430-elfbare-crtstuff: New file.
	* configure: Regenerate.
	* configure.ac: Disable TM clone registry by default for
	msp430-elfbare.
---
 contrib/config-list.mk                        |   2 +-
 gcc/config.gcc                                |  14 +-
 gcc/config/msp430/msp430-devices.c            |  16 +-
 gcc/config/msp430/msp430.c                    |  10 +
 gcc/config/msp430/t-msp430                    |   2 +-
 gcc/doc/install.texi                          |  16 +-
 gcc/doc/invoke.texi                           |   4 +-
 gcc/testsuite/g++.dg/init/dso_handle1.C       |   1 +
 gcc/testsuite/g++.dg/init/dso_handle2.C       |   1 +
 gcc/testsuite/g++.dg/other/cxa-atexit1.C      |   1 +
 gcc/testsuite/gcc.target/msp430/msp430.exp    |   8 +-
 libgcc/config.host                            |  20 +-
 .../config/msp430/msp430-elfbare-crtstuff.c   | 761 ++++++++++++++++++
 libgcc/config/msp430/t-msp430                 |   6 -
 libgcc/config/msp430/t-msp430-crtstuff        |  29 +
 .../config/msp430/t-msp430-elfbare-crtstuff   |  43 +
 libgcc/configure                              |   9 +
 libgcc/configure.ac                           |   8 +
 18 files changed, 933 insertions(+), 18 deletions(-)
 create mode 100644 libgcc/config/msp430/msp430-elfbare-crtstuff.c
 create mode 100644 libgcc/config/msp430/t-msp430-crtstuff
 create mode 100644 libgcc/config/msp430/t-msp430-elfbare-crtstuff

diff --git a/contrib/config-list.mk b/contrib/config-list.mk
index a5f5d7bbd5a..d154286a497 100644
--- a/contrib/config-list.mk
+++ b/contrib/config-list.mk
@@ -68,7 +68,7 @@  LIST = aarch64-elf aarch64-linux-gnu aarch64-rtems \
   mipsel-elf mips64-elf mips64vr-elf mips64orion-elf mips-rtems \
   mips-wrs-vxworks mipstx39-elf mmix-knuth-mmixware mn10300-elf moxie-elf \
   moxie-uclinux moxie-rtems \
-  msp430-elf \
+  msp430-elf msp430-elfbare \
   nds32le-elf nds32be-elf \
   nios2-elf nios2-linux-gnu nios2-rtems \
   nvptx-none \
diff --git a/gcc/config.gcc b/gcc/config.gcc
index 5aa0130135f..9802f436e06 100644
--- a/gcc/config.gcc
+++ b/gcc/config.gcc
@@ -2624,7 +2624,7 @@  mn10300-*-*)
 	use_collect2=no
 	use_gcc_stdint=wrap
 	;;
-msp430*-*-*)
+msp430-*-*)
 	tm_file="dbxelf.h elfos.h newlib-stdint.h ${tm_file}"
 	c_target_objs="msp430-c.o"
 	cxx_target_objs="msp430-c.o"
@@ -2637,6 +2637,18 @@  msp430*-*-*)
 	if test x${disable_initfini_array} != xyes; then
 		gcc_cv_initfini_array=yes
 	fi
+	case ${target} in
+	  msp430-*-elfbare)
+	    # __cxa_atexit increases code size, and we don't need to support
+	    # dynamic shared objects on MSP430, so regular Newlib atexit is a
+	    # fine replacement as it also supports registration of more than 32
+	    # functions.
+	    default_use_cxa_atexit=no
+	    # This target does not match the generic *-*-elf case above which
+	    # sets use_gcc_stdint=wrap, so explicitly set it here.
+	    use_gcc_stdint=wrap
+	    ;;
+	esac
 	;;
 nds32*-*-*)
 	target_cpu_default="0"
diff --git a/gcc/config/msp430/msp430-devices.c b/gcc/config/msp430/msp430-devices.c
index 600a111b517..e734da2cdc9 100644
--- a/gcc/config/msp430/msp430-devices.c
+++ b/gcc/config/msp430/msp430-devices.c
@@ -71,8 +71,22 @@  msp430_dirname (char *path)
   return path;
 }
 
+/* We need to support both the msp430-elf and msp430-elfbare target aliases.
+   gcc/config/msp430/t-msp430 will define TARGET_SUBDIR to the target_subdir
+   Makefile variable, which will evaluate to the correct subdirectory that
+   needs to be searched for devices.csv.  */
+#ifndef TARGET_SUBDIR
+#define TARGET_SUBDIR msp430-elf
+#endif
+
+#define _MSPMKSTR(x) __MSPMKSTR(x)
+#define __MSPMKSTR(x) #x
+
 /* devices.csv path from the toolchain root.  */
-static const char rest_of_devices_path[] = "/msp430-elf/include/devices/";
+static const char rest_of_devices_path[] = "/" _MSPMKSTR(TARGET_SUBDIR) "/include/devices/";
+
+#undef _MSPMKSTR
+#undef __MSPMKSTR
 
 /* "The default value of GCC_EXEC_PREFIX is prefix/lib/gcc". Strip lib/gcc
    from GCC_EXEC_PREFIX to get the path to the installed toolchain.  */
diff --git a/gcc/config/msp430/msp430.c b/gcc/config/msp430/msp430.c
index 4ebdcf51e8b..d0892f2c266 100644
--- a/gcc/config/msp430/msp430.c
+++ b/gcc/config/msp430/msp430.c
@@ -288,6 +288,16 @@  msp430_option_override (void)
   if (TARGET_OPT_SPACE && optimize < 3)
     optimize_size = 1;
 
+#if !DEFAULT_USE_CXA_ATEXIT
+  /* For some configurations, we use atexit() instead of __cxa_atexit() by
+     default to save on code size and remove the declaration of __dso_handle
+     from the CRT library.
+     Configuring GCC with --enable-__cxa-atexit re-enables it by defining
+     DEFAULT_USE_CXA_ATEXIT to 1.  */
+  if (flag_use_cxa_atexit)
+    error ("%<-fuse-cxa-atexit%> is not supported for msp430-elf");
+#endif
+
 #ifndef HAVE_NEWLIB_NANO_FORMATTED_IO
   if (TARGET_TINY_PRINTF)
     error ("GCC must be configured with %<--enable-newlib-nano-formatted-io%> "
diff --git a/gcc/config/msp430/t-msp430 b/gcc/config/msp430/t-msp430
index e180ce3efdb..d481696220a 100644
--- a/gcc/config/msp430/t-msp430
+++ b/gcc/config/msp430/t-msp430
@@ -24,7 +24,7 @@  driver-msp430.o: $(srcdir)/config/msp430/driver-msp430.c \
 
 msp430-devices.o: $(srcdir)/config/msp430/msp430-devices.c \
 	$(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H)
-	$(COMPILER) -c $(ALL_COMPILERFLAGS) $(ALL_CPPFLAGS) $(INCLUDES) $<
+	$(COMPILER) -c $(ALL_COMPILERFLAGS) $(ALL_CPPFLAGS) -DTARGET_SUBDIR=$(target_subdir) $(INCLUDES) $<
 
 # Enable multilibs:
 
diff --git a/gcc/doc/install.texi b/gcc/doc/install.texi
index d926ca2e920..14e9175bf27 100644
--- a/gcc/doc/install.texi
+++ b/gcc/doc/install.texi
@@ -4330,10 +4330,24 @@  The moxie processor.
 <hr />
 @end html
 @anchor{msp430-x-elf}
-@heading msp430-*-elf
+@heading msp430-*-elf*
 TI MSP430 processor.
 This configuration is intended for embedded systems.
 
+@samp{msp430-*-elf} is the standard configuration with most GCC
+features enabled by default.
+
+@samp{msp430-*-elfbare} is tuned for a bare-metal environment, and disables
+features related to shared libraries and other functionality not used for
+this device. This reduces code and data usage of the GCC libraries, resulting
+in a minimal run-time environment by default.
+
+Features disabled by default include:
+@itemize
+@item transactional memory
+@item __cxa_atexit
+@end itemize
+
 @html
 <hr />
 @end html
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 403be47d893..56421045cd9 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -23282,8 +23282,8 @@  this directory for devices.csv.  If devices.csv is found, this directory will
 also be registered as an include path, and linker library path.  Header files
 and linker scripts in this directory can therefore be used without manually
 specifying @code{-I} and @code{-L} on the command line.
-@item The @samp{msp430-elf/include/devices} directory
-Finally, GCC will examine @samp{msp430-elf/include/devices} from the
+@item The @samp{msp430-elf@{,bare@}/include/devices} directory
+Finally, GCC will examine @samp{msp430-elf@{,bare@}/include/devices} from the
 toolchain root directory.  This directory does not exist in a default
 installation, but if the user has created it and copied @samp{devices.csv}
 there, then the MCU data will be read.  As above, this directory will
diff --git a/gcc/testsuite/g++.dg/init/dso_handle1.C b/gcc/testsuite/g++.dg/init/dso_handle1.C
index 97f67cad8f4..0377c4ef7c0 100644
--- a/gcc/testsuite/g++.dg/init/dso_handle1.C
+++ b/gcc/testsuite/g++.dg/init/dso_handle1.C
@@ -1,6 +1,7 @@ 
 // PR c++/17042
 // { dg-do assemble }
 /* { dg-require-weak "" } */
+// { dg-require-effective-target cxa_atexit }
 // { dg-options "-fuse-cxa-atexit" }
 
 struct A
diff --git a/gcc/testsuite/g++.dg/init/dso_handle2.C b/gcc/testsuite/g++.dg/init/dso_handle2.C
index b219dc02611..a4daaf3f7da 100644
--- a/gcc/testsuite/g++.dg/init/dso_handle2.C
+++ b/gcc/testsuite/g++.dg/init/dso_handle2.C
@@ -1,4 +1,5 @@ 
 // PR c++/58846
+// { dg-require-effective-target cxa_atexit }
 // { dg-options "-fuse-cxa-atexit" }
 
 extern "C" { char* __dso_handle; }
diff --git a/gcc/testsuite/g++.dg/other/cxa-atexit1.C b/gcc/testsuite/g++.dg/other/cxa-atexit1.C
index a51f3340142..b22911db2e0 100644
--- a/gcc/testsuite/g++.dg/other/cxa-atexit1.C
+++ b/gcc/testsuite/g++.dg/other/cxa-atexit1.C
@@ -1,4 +1,5 @@ 
 // { dg-do compile }
+// { dg-require-effective-target cxa_atexit }
 // { dg-options "-O2 -fuse-cxa-atexit" }
 
 # 1 "cxa-atexit1.C"
diff --git a/gcc/testsuite/gcc.target/msp430/msp430.exp b/gcc/testsuite/gcc.target/msp430/msp430.exp
index 37586612b9a..42dc91136c9 100644
--- a/gcc/testsuite/gcc.target/msp430/msp430.exp
+++ b/gcc/testsuite/gcc.target/msp430/msp430.exp
@@ -141,18 +141,20 @@  proc msp430_device_permutations_runtest { tests } {
 }
 
 
-# Return $TOOLCHAIN_ROOT/msp430-elf/include/devices/
+# Return $TOOLCHAIN_ROOT/$target_alias/include/devices/
+# target_alias is expected to be either msp430-elf or msp430-elfbare.
 proc get_installed_device_data_path { } {
+    global target_alias
     set compiler [lindex [regexp -all -inline {\S+} \
 	[board_info [target_info name] compiler]] 0]
     # $compiler is actually a file, but normalize will still get us the desired
     # result.
     return [file normalize \
-	"$compiler/../../msp430-elf/include/devices/devices.csv"]
+	"$compiler/../../$target_alias/include/devices/devices.csv"]
 }
 
 # If the devices.csv is installed in
-# $TOOLCHAIN_ROOT/msp430-elf/include/devices/, rename it so it doesn't
+# $TOOLCHAIN_ROOT/$target_alias/include/devices/, rename it so it doesn't
 # interfere with the hard-coded device data tests.
 proc msp430_hide_installed_devices_data { } {
     set devices_path [get_installed_device_data_path]
diff --git a/libgcc/config.host b/libgcc/config.host
index 56868719fc8..ce99282b69b 100644
--- a/libgcc/config.host
+++ b/libgcc/config.host
@@ -1043,8 +1043,24 @@  moxie-*-elf | moxie-*-moxiebox* | moxie-*-uclinux* | moxie-*-rtems*)
 	tmake_file="$tmake_file moxie/t-moxie t-softfp-sfdf t-softfp-excl t-softfp"
 	extra_parts="$extra_parts crti.o crtn.o crtbegin.o crtend.o"
 	;;
-msp430*-*-elf)
-	tmake_file="$tm_file t-crtstuff t-fdpbit msp430/t-msp430"
+msp430-*-elf*)
+	tmake_file="$tm_file t-fdpbit msp430/t-msp430"
+	case ${host} in
+	  msp430-*-elfbare)
+	    if test x$enable___cxa_atexit = xyes; then
+	      # We must use the standard crtstuff in this case.
+	      tmake_file="$tmake_file msp430/t-msp430-crtstuff"
+	    else
+	      tmake_file="$tmake_file msp430/t-msp430-elfbare-crtstuff"
+	      # crt{begin,end}.o must be explicitly specified since we use a
+	      # custom crtstuff.c.
+	      extra_parts="$extra_parts crtbegin.o crtend.o"
+	    fi
+	    ;;
+	  *)
+	    tmake_file="$tmake_file msp430/t-msp430-crtstuff"
+	    ;;
+	esac
 	extra_parts="$extra_parts crtbegin_no_eh.o crtend_no_eh.o"
 	extra_parts="$extra_parts libmul_none.a libmul_16.a libmul_32.a libmul_f5.a"
 	;;
diff --git a/libgcc/config/msp430/msp430-elfbare-crtstuff.c b/libgcc/config/msp430/msp430-elfbare-crtstuff.c
new file mode 100644
index 00000000000..eb6d1f8dea0
--- /dev/null
+++ b/libgcc/config/msp430/msp430-elfbare-crtstuff.c
@@ -0,0 +1,761 @@ 
+/* Specialized bits of code needed to support construction and
+   destruction of file-scope objects in C++ code.
+   This version of crtstuff.c has been slightly modified for the msp430-elfbare
+   configuration, by adding some new macros which, when defined, will remove
+   some standard GCC functionality.
+   Copyright (C) 1991-2019 Free Software Foundation, Inc.
+   Contributed by Ron Guilmette (rfg@monkeys.com).
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC 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 General Public License
+for more details.
+
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+<http://www.gnu.org/licenses/>.  */
+
+/* This file is a bit like libgcc2.c in that it is compiled
+   multiple times and yields multiple .o files.
+
+   This file is useful on target machines where the object file format
+   supports multiple "user-defined" sections (e.g. COFF, ELF, ROSE).  On
+   such systems, this file allows us to avoid running collect (or any
+   other such slow and painful kludge).  Additionally, if the target
+   system supports a .init section, this file allows us to support the
+   linking of C++ code with a non-C++ main program.
+
+   Note that if INIT_SECTION_ASM_OP is defined in the tm.h file, then
+   this file *will* make use of the .init section.  If that symbol is
+   not defined however, then the .init section will not be used.
+
+   Currently, only ELF and COFF are supported.  It is likely however that
+   ROSE could also be supported, if someone was willing to do the work to
+   make whatever (small?) adaptations are needed.  (Some work may be
+   needed on the ROSE assembler and linker also.)
+
+   This file must be compiled with gcc.  */
+
+/* Target machine header files require this define. */
+#define IN_LIBGCC2
+
+/* FIXME: Including auto-host is incorrect, but until we have
+   identified the set of defines that need to go into auto-target.h,
+   this will have to do.  */
+#include "auto-host.h"
+#undef caddr_t
+#undef pid_t
+#undef rlim_t
+#undef ssize_t
+#undef vfork
+#include "tconfig.h"
+#include "tsystem.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "libgcc_tm.h"
+#include "unwind-dw2-fde.h"
+
+#ifndef FORCE_CODE_SECTION_ALIGN
+# define FORCE_CODE_SECTION_ALIGN
+#endif
+
+#ifndef CRT_CALL_STATIC_FUNCTION
+# define CRT_CALL_STATIC_FUNCTION(SECTION_OP, FUNC)	\
+static void __attribute__((__used__))			\
+call_ ## FUNC (void)					\
+{							\
+  asm (SECTION_OP);					\
+  FUNC ();						\
+  FORCE_CODE_SECTION_ALIGN				\
+  asm (__LIBGCC_TEXT_SECTION_ASM_OP__);				\
+}
+#endif
+
+#if defined(TARGET_DL_ITERATE_PHDR) && \
+   (defined(__DragonFly__) || defined(__FreeBSD__) || defined(__NetBSD__))
+#define BSD_DL_ITERATE_PHDR_AVAILABLE
+#endif
+ 
+#if defined(OBJECT_FORMAT_ELF) \
+    && !defined(OBJECT_FORMAT_FLAT) \
+    && defined(HAVE_LD_EH_FRAME_HDR) \
+    && !defined(inhibit_libc) && !defined(CRTSTUFFT_O) \
+    && defined(BSD_DL_ITERATE_PHDR_AVAILABLE)
+#include <link.h>
+# define USE_PT_GNU_EH_FRAME
+#endif
+
+#if defined(OBJECT_FORMAT_ELF) \
+    && !defined(OBJECT_FORMAT_FLAT) \
+    && defined(HAVE_LD_EH_FRAME_HDR) && defined(TARGET_DL_ITERATE_PHDR) \
+    && !defined(inhibit_libc) && !defined(CRTSTUFFT_O) \
+    && defined(__sun__) && defined(__svr4__)
+#include <link.h>
+# define USE_PT_GNU_EH_FRAME
+#endif
+
+#if defined(OBJECT_FORMAT_ELF) \
+    && !defined(OBJECT_FORMAT_FLAT) \
+    && defined(HAVE_LD_EH_FRAME_HDR) \
+    && !defined(inhibit_libc) && !defined(CRTSTUFFT_O) \
+    && defined(__GLIBC__) && __GLIBC__ >= 2
+#include <link.h>
+/* uClibc pretends to be glibc 2.2 and DT_CONFIG is defined in its link.h.
+   But it doesn't use PT_GNU_EH_FRAME ELF segment currently.  */
+# if !defined(__UCLIBC__) \
+     && (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 2) \
+     || (__GLIBC__ == 2 && __GLIBC_MINOR__ == 2 && defined(DT_CONFIG)))
+#  define USE_PT_GNU_EH_FRAME
+# endif
+#endif
+
+#if defined(OBJECT_FORMAT_ELF) \
+    && !defined(OBJECT_FORMAT_FLAT) \
+    && defined(HAVE_LD_EH_FRAME_HDR) \
+    && !defined(CRTSTUFFT_O) \
+    && defined(inhibit_libc) \
+    && (defined(__GLIBC__) || defined(__gnu_linux__) || defined(__GNU__))
+/* On systems using glibc, an inhibit_libc build of libgcc is only
+   part of a bootstrap process.  Build the same crt*.o as would be
+   built with headers present, so that it is not necessary to build
+   glibc more than once for the bootstrap to converge.  */
+# define USE_PT_GNU_EH_FRAME
+#endif
+
+#ifdef USE_EH_FRAME_REGISTRY_ALWAYS
+# ifndef __LIBGCC_EH_FRAME_SECTION_NAME__
+#  error "Can't use explicit exception-frame-registration without __LIBGCC_EH_FRAME_SECTION_NAME__"
+# endif
+#endif
+#if defined(__LIBGCC_EH_FRAME_SECTION_NAME__) && (!defined(USE_PT_GNU_EH_FRAME) || defined(USE_EH_FRAME_REGISTRY_ALWAYS))
+# define USE_EH_FRAME_REGISTRY
+#endif
+#if defined(__LIBGCC_EH_FRAME_SECTION_NAME__) \
+    && __LIBGCC_EH_TABLES_CAN_BE_READ_ONLY__
+# define EH_FRAME_SECTION_CONST const
+#else
+# define EH_FRAME_SECTION_CONST
+#endif
+
+#if !defined(DTOR_LIST_END) && defined(OBJECT_FORMAT_ELF) \
+    && defined(HAVE_GAS_HIDDEN) && !defined(FINI_ARRAY_SECTION_ASM_OP)
+# define HIDDEN_DTOR_LIST_END
+#endif
+
+#if !defined(USE_TM_CLONE_REGISTRY) && defined(OBJECT_FORMAT_ELF)
+# define USE_TM_CLONE_REGISTRY 1
+#elif !defined(USE_TM_CLONE_REGISTRY)
+# define USE_TM_CLONE_REGISTRY 0
+#endif
+
+/* We do not want to add the weak attribute to the declarations of these
+   routines in unwind-dw2-fde.h because that will cause the definition of
+   these symbols to be weak as well.
+
+   This exposes a core issue, how to handle creating weak references vs
+   how to create weak definitions.  Either we have to have the definition
+   of TARGET_WEAK_ATTRIBUTE be conditional in the shared header files or
+   have a second declaration if we want a function's references to be weak,
+   but not its definition.
+
+   Making TARGET_WEAK_ATTRIBUTE conditional seems like a good solution until
+   one thinks about scaling to larger problems -- i.e., the condition under
+   which TARGET_WEAK_ATTRIBUTE is active will eventually get far too
+   complicated.
+
+   So, we take an approach similar to #pragma weak -- we have a second
+   declaration for functions that we want to have weak references.
+
+   Neither way is particularly good.  */
+
+/* References to __register_frame_info and __deregister_frame_info should
+   be weak in this file if at all possible.  */
+extern void __register_frame_info (const void *, struct object *)
+				  TARGET_ATTRIBUTE_WEAK;
+extern void __register_frame_info_bases (const void *, struct object *,
+					 void *, void *)
+				  TARGET_ATTRIBUTE_WEAK;
+extern void *__deregister_frame_info (const void *)
+				     TARGET_ATTRIBUTE_WEAK;
+extern void *__deregister_frame_info_bases (const void *)
+				     TARGET_ATTRIBUTE_WEAK;
+extern void __do_global_ctors_1 (void);
+
+/* Likewise for transactional memory clone tables.  */
+extern void _ITM_registerTMCloneTable (void *, size_t) TARGET_ATTRIBUTE_WEAK;
+extern void _ITM_deregisterTMCloneTable (void *) TARGET_ATTRIBUTE_WEAK;
+
+#ifdef OBJECT_FORMAT_ELF
+
+/*  Declare a pointer to void function type.  */
+typedef void (*func_ptr) (void);
+#define STATIC static
+
+#else  /* OBJECT_FORMAT_ELF */
+
+#include "gbl-ctors.h"
+
+#define STATIC
+
+#endif /* OBJECT_FORMAT_ELF */
+
+#ifdef CRT_BEGIN
+
+/* NOTE:  In order to be able to support SVR4 shared libraries, we arrange
+   to have one set of symbols { __CTOR_LIST__, __DTOR_LIST__, __CTOR_END__,
+   __DTOR_END__ } per root executable and also one set of these symbols
+   per shared library.  So in any given whole process image, we may have
+   multiple definitions of each of these symbols.  In order to prevent
+   these definitions from conflicting with one another, and in order to
+   ensure that the proper lists are used for the initialization/finalization
+   of each individual shared library (respectively), we give these symbols
+   only internal (i.e. `static') linkage, and we also make it a point to
+   refer to only the __CTOR_END__ symbol in crtend.o and the __DTOR_LIST__
+   symbol in crtbegin.o, where they are defined.  */
+
+/* No need for .ctors/.dtors section if linker can place them in
+   .init_array/.fini_array section.  */
+#ifndef USE_INITFINI_ARRAY
+/* The -1 is a flag to __do_global_[cd]tors indicating that this table
+   does not start with a count of elements.  */
+#ifdef CTOR_LIST_BEGIN
+CTOR_LIST_BEGIN;
+#elif defined(__LIBGCC_CTORS_SECTION_ASM_OP__)
+/* Hack: force cc1 to switch to .data section early, so that assembling
+   __CTOR_LIST__ does not undo our behind-the-back change to .ctors.  */
+static func_ptr force_to_data[1] __attribute__ ((__used__)) = { };
+asm (__LIBGCC_CTORS_SECTION_ASM_OP__);
+STATIC func_ptr __CTOR_LIST__[1]
+  __attribute__ ((__used__, aligned(__alignof__(func_ptr))))
+  = { (func_ptr) (-1) };
+#else
+STATIC func_ptr __CTOR_LIST__[1]
+  __attribute__ ((__used__, section(".ctors"), aligned(__alignof__(func_ptr))))
+  = { (func_ptr) (-1) };
+#endif /* __CTOR_LIST__ alternatives */
+
+#ifdef DTOR_LIST_BEGIN
+DTOR_LIST_BEGIN;
+#elif defined(__LIBGCC_DTORS_SECTION_ASM_OP__)
+asm (__LIBGCC_DTORS_SECTION_ASM_OP__);
+STATIC func_ptr __DTOR_LIST__[1]
+  __attribute__ ((aligned(__alignof__(func_ptr))))
+  = { (func_ptr) (-1) };
+#else
+STATIC func_ptr __DTOR_LIST__[1]
+  __attribute__((section(".dtors"), aligned(__alignof__(func_ptr))))
+  = { (func_ptr) (-1) };
+#endif /* __DTOR_LIST__ alternatives */
+#endif /* USE_INITFINI_ARRAY */
+
+#ifdef USE_EH_FRAME_REGISTRY
+/* Stick a label at the beginning of the frame unwind info so we can register
+   and deregister it with the exception handling library code.  */
+STATIC EH_FRAME_SECTION_CONST char __EH_FRAME_BEGIN__[]
+     __attribute__((section(__LIBGCC_EH_FRAME_SECTION_NAME__), aligned(4)))
+     = { };
+#endif /* USE_EH_FRAME_REGISTRY */
+
+#if USE_TM_CLONE_REGISTRY
+STATIC func_ptr __TMC_LIST__[]
+  __attribute__((used, section(".tm_clone_table"), aligned(__alignof__(void*))))
+  = { };
+# ifdef HAVE_GAS_HIDDEN
+extern func_ptr __TMC_END__[] __attribute__((__visibility__ ("hidden")));
+# endif
+
+static inline void
+deregister_tm_clones (void)
+{
+  void (*fn) (void *);
+
+#ifdef HAVE_GAS_HIDDEN
+  func_ptr *end = __TMC_END__;
+  // Do not optimize the comparison to false.
+  __asm ("" : "+g" (end));
+  if (__TMC_LIST__ == end)
+    return;
+#else
+  if (__TMC_LIST__[0] == NULL)
+    return;
+#endif
+
+  fn = _ITM_deregisterTMCloneTable;
+  __asm ("" : "+r" (fn));
+  if (fn)
+    fn (__TMC_LIST__);
+}
+
+static inline void
+register_tm_clones (void)
+{
+  void (*fn) (void *, size_t);
+  size_t size;
+
+#ifdef HAVE_GAS_HIDDEN
+  func_ptr *end = __TMC_END__;
+  // Do not optimize the comparison to false.
+  __asm ("" : "+g" (end));
+  size = (end - __TMC_LIST__) / 2;
+#else
+  for (size = 0; __TMC_LIST__[size * 2] != NULL; size++)
+    continue;
+#endif
+  if (size == 0)
+    return;
+
+  fn = _ITM_registerTMCloneTable;
+  __asm ("" : "+r" (fn));
+  if (fn)
+    fn (__TMC_LIST__, size);
+}
+#endif /* USE_TM_CLONE_REGISTRY */
+
+#if defined(__LIBGCC_INIT_SECTION_ASM_OP__) \
+    || defined(__LIBGCC_INIT_ARRAY_SECTION_ASM_OP__)
+
+#ifdef OBJECT_FORMAT_ELF
+
+#ifndef MSP430_CRTSTUFF_NO_DSO_HANDLE
+/* Declare the __dso_handle variable.  It should have a unique value
+   in every shared-object; in a main program its value is zero.  The
+   object should in any case be protected.  This means the instance
+   in one DSO or the main program is not used in another object.  The
+   dynamic linker takes care of this.  */
+
+#ifdef TARGET_LIBGCC_SDATA_SECTION
+extern void *__dso_handle __attribute__ ((__section__ (TARGET_LIBGCC_SDATA_SECTION)));
+#endif
+#ifdef HAVE_GAS_HIDDEN
+extern void *__dso_handle __attribute__ ((__visibility__ ("hidden")));
+#endif
+#ifdef CRTSTUFFS_O
+void *__dso_handle = &__dso_handle;
+#else
+void *__dso_handle = 0;
+#endif
+#endif /* MSP430_CRTSTUFF_NO_DSO_HANDLE */
+
+/* The __cxa_finalize function may not be available so we use only a
+   weak declaration.  */
+extern void __cxa_finalize (void *) TARGET_ATTRIBUTE_WEAK;
+
+/* Run all the global destructors on exit from the program.  */
+
+/* Some systems place the number of pointers in the first word of the
+   table.  On SVR4 however, that word is -1.  In all cases, the table is
+   null-terminated.  On SVR4, we start from the beginning of the list and
+   invoke each per-compilation-unit destructor routine in order
+   until we find that null.
+
+   Note that this function MUST be static.  There will be one of these
+   functions in each root executable and one in each shared library, but
+   although they all have the same code, each one is unique in that it
+   refers to one particular associated `__DTOR_LIST__' which belongs to the
+   same particular root executable or shared library file.
+
+   On some systems, this routine is run more than once from the .fini,
+   when exit is called recursively, so we arrange to remember where in
+   the list we left off processing, and we resume at that point,
+   should we be re-invoked.
+
+   This routine does not need to be run if none of the following clauses are
+   true, as it will not do anything, so can be removed.  */
+#if defined(CRTSTUFFS_O) || !defined(FINI_ARRAY_SECTION_ASM_OP) \
+  || USE_TM_CLONE_REGISTRY || defined(USE_EH_FRAME_REGISTRY)
+static void __attribute__((used))
+__do_global_dtors_aux (void)
+{
+  static _Bool completed;
+
+  if (__builtin_expect (completed, 0))
+    return;
+
+#ifdef CRTSTUFFS_O
+  if (__cxa_finalize)
+    __cxa_finalize (__dso_handle);
+#endif
+
+#ifdef FINI_ARRAY_SECTION_ASM_OP
+  /* If we are using .fini_array then destructors will be run via that
+     mechanism.  */
+#elif defined(HIDDEN_DTOR_LIST_END)
+  {
+    /* Safer version that makes sure only .dtors function pointers are
+       called even if the static variable is maliciously changed.  */
+    extern func_ptr __DTOR_END__[] __attribute__((visibility ("hidden")));
+    static size_t dtor_idx;
+    const size_t max_idx = __DTOR_END__ - __DTOR_LIST__ - 1;
+    func_ptr *dtor_list;
+
+    __asm ("" : "=g" (dtor_list) : "0" (__DTOR_LIST__));
+    while (dtor_idx < max_idx)
+      dtor_list[++dtor_idx] ();
+  }
+#else /* !defined (FINI_ARRAY_SECTION_ASM_OP) */
+  {
+    static func_ptr *p = __DTOR_LIST__ + 1;
+    func_ptr f;
+
+    while ((f = *p))
+      {
+	p++;
+	f ();
+      }
+  }
+#endif /* !defined(FINI_ARRAY_SECTION_ASM_OP) */
+
+#if USE_TM_CLONE_REGISTRY
+  deregister_tm_clones ();
+#endif /* USE_TM_CLONE_REGISTRY */
+
+#ifdef USE_EH_FRAME_REGISTRY
+#ifdef CRT_GET_RFIB_DATA
+  /* If we used the new __register_frame_info_bases interface,
+     make sure that we deregister from the same place.  */
+  if (__deregister_frame_info_bases)
+    __deregister_frame_info_bases (__EH_FRAME_BEGIN__);
+#else
+  if (__deregister_frame_info)
+    __deregister_frame_info (__EH_FRAME_BEGIN__);
+#endif
+#endif
+
+  completed = 1;
+}
+
+/* Stick a call to __do_global_dtors_aux into the .fini section.  */
+#ifdef FINI_SECTION_ASM_OP
+CRT_CALL_STATIC_FUNCTION (FINI_SECTION_ASM_OP, __do_global_dtors_aux)
+#elif defined (FINI_ARRAY_SECTION_ASM_OP)
+#if defined(__FDPIC__)
+__asm__("\t.equ\t__do_global_dtors_aux_alias, __do_global_dtors_aux\n");
+extern char __do_global_dtors_aux_alias;
+static void *__do_global_dtors_aux_fini_array_entry[]
+__attribute__ ((__used__, section(".fini_array"), aligned(sizeof(void *))))
+     = { &__do_global_dtors_aux_alias };
+#else /* defined(__FDPIC__) */
+static func_ptr __do_global_dtors_aux_fini_array_entry[]
+  __attribute__ ((__used__, section(".fini_array"),
+		  aligned(__alignof__(func_ptr)))) = { __do_global_dtors_aux };
+#endif /* defined(__FDPIC__) */
+#else /* !FINI_SECTION_ASM_OP && !FINI_ARRAY_SECTION_ASM_OP */
+static void __attribute__((used))
+__do_global_dtors_aux_1 (void)
+{
+  atexit (__do_global_dtors_aux);
+}
+CRT_CALL_STATIC_FUNCTION (__LIBGCC_INIT_SECTION_ASM_OP__,
+			  __do_global_dtors_aux_1)
+#endif
+#endif /* defined(CRTSTUFFS_O) || !defined(FINI_ARRAY_SECTION_ASM_OP)
+  || USE_TM_CLONE_REGISTRY || defined(USE_EH_FRAME_REGISTRY) */
+
+
+#if defined(USE_EH_FRAME_REGISTRY) || USE_TM_CLONE_REGISTRY
+/* Stick a call to __register_frame_info into the .init section.  For some
+   reason calls with no arguments work more reliably in .init, so stick the
+   call in another function.  */
+
+static void __attribute__((used))
+frame_dummy (void)
+{
+#ifdef USE_EH_FRAME_REGISTRY
+  static struct object object;
+#ifdef CRT_GET_RFIB_DATA
+  void *tbase, *dbase;
+  tbase = 0;
+  CRT_GET_RFIB_DATA (dbase);
+  if (__register_frame_info_bases)
+    __register_frame_info_bases (__EH_FRAME_BEGIN__, &object, tbase, dbase);
+#else
+  if (__register_frame_info)
+    __register_frame_info (__EH_FRAME_BEGIN__, &object);
+#endif /* CRT_GET_RFIB_DATA */
+#endif /* USE_EH_FRAME_REGISTRY */
+
+#if USE_TM_CLONE_REGISTRY
+  register_tm_clones ();
+#endif /* USE_TM_CLONE_REGISTRY */
+}
+
+#ifdef __LIBGCC_INIT_SECTION_ASM_OP__
+CRT_CALL_STATIC_FUNCTION (__LIBGCC_INIT_SECTION_ASM_OP__, frame_dummy)
+#else /* defined(__LIBGCC_INIT_SECTION_ASM_OP__) */
+#if defined(__FDPIC__)
+__asm__("\t.equ\t__frame_dummy_alias, frame_dummy\n");
+extern char __frame_dummy_alias;
+static void *__frame_dummy_init_array_entry[]
+__attribute__ ((__used__, section(".init_array"), aligned(sizeof(void *))))
+     = { &__frame_dummy_alias };
+#else /* defined(__FDPIC__) */
+static func_ptr __frame_dummy_init_array_entry[]
+  __attribute__ ((__used__, section(".init_array"),
+		  aligned(__alignof__(func_ptr)))) = { frame_dummy };
+#endif /* defined(__FDPIC__) */
+#endif /* !defined(__LIBGCC_INIT_SECTION_ASM_OP__) */
+#endif /* USE_EH_FRAME_REGISTRY || USE_TM_CLONE_REGISTRY */
+
+#else  /* OBJECT_FORMAT_ELF */
+
+/* The function __do_global_ctors_aux is compiled twice (once in crtbegin.o
+   and once in crtend.o).  It must be declared static to avoid a link
+   error.  Here, we define __do_global_ctors as an externally callable
+   function.  It is externally callable so that __main can invoke it when
+   INVOKE__main is defined.  This has the additional effect of forcing cc1
+   to switch to the .text section.  */
+
+static void __do_global_ctors_aux (void);
+void
+__do_global_ctors (void)
+{
+#ifdef INVOKE__main
+  /* If __main won't actually call __do_global_ctors then it doesn't matter
+     what's inside the function.  The inside of __do_global_ctors_aux is
+     called automatically in that case.  And the Alliant fx2800 linker
+     crashes on this reference.  So prevent the crash.  */
+  __do_global_ctors_aux ();
+#endif
+}
+
+asm (__LIBGCC_INIT_SECTION_ASM_OP__);	/* cc1 doesn't know that we are switching! */
+
+/* A routine to invoke all of the global constructors upon entry to the
+   program.  We put this into the .init section (for systems that have
+   such a thing) so that we can properly perform the construction of
+   file-scope static-storage C++ objects within shared libraries.  */
+
+static void __attribute__((used))
+__do_global_ctors_aux (void)	/* prologue goes in .init section */
+{
+  FORCE_CODE_SECTION_ALIGN	/* explicit align before switch to .text */
+  asm (__LIBGCC_TEXT_SECTION_ASM_OP__);	/* don't put epilogue and body in .init */
+  DO_GLOBAL_CTORS_BODY;
+  atexit (__do_global_dtors);
+}
+
+#endif /* OBJECT_FORMAT_ELF */
+
+#elif defined(HAS_INIT_SECTION) /* ! __LIBGCC_INIT_SECTION_ASM_OP__ */
+
+extern void __do_global_dtors (void);
+
+/* This case is used by the Irix 6 port, which supports named sections but
+   not an SVR4-style .fini section.  __do_global_dtors can be non-static
+   in this case because we protect it with -hidden_symbol.  */
+
+void
+__do_global_dtors (void)
+{
+  func_ptr *p, f;
+  for (p = __DTOR_LIST__ + 1; (f = *p); p++)
+    f ();
+
+#if USE_TM_CLONE_REGISTRY
+  deregister_tm_clones ();
+#endif /* USE_TM_CLONE_REGISTRY */
+
+#ifdef USE_EH_FRAME_REGISTRY
+  if (__deregister_frame_info)
+    __deregister_frame_info (__EH_FRAME_BEGIN__);
+#endif
+}
+
+#if defined(USE_EH_FRAME_REGISTRY) || USE_TM_CLONE_REGISTRY
+/* A helper function for __do_global_ctors, which is in crtend.o.  Here
+   in crtbegin.o, we can reference a couple of symbols not visible there.
+   Plus, since we're before libgcc.a, we have no problems referencing
+   functions from there.  */
+void
+__do_global_ctors_1(void)
+{
+#ifdef USE_EH_FRAME_REGISTRY
+  static struct object object;
+  if (__register_frame_info)
+    __register_frame_info (__EH_FRAME_BEGIN__, &object);
+#endif
+
+#if USE_TM_CLONE_REGISTRY
+  register_tm_clones ();
+#endif /* USE_TM_CLONE_REGISTRY */
+}
+#endif /* USE_EH_FRAME_REGISTRY || USE_TM_CLONE_REGISTRY */
+
+#else /* ! __LIBGCC_INIT_SECTION_ASM_OP__ && ! HAS_INIT_SECTION */
+#error "What are you doing with crtstuff.c, then?"
+#endif
+
+#elif defined(CRT_END) /* ! CRT_BEGIN */
+
+/* No need for .ctors/.dtors section if linker can place them in
+   .init_array/.fini_array section.  */
+#ifndef USE_INITFINI_ARRAY
+/* Put a word containing zero at the end of each of our two lists of function
+   addresses.  Note that the words defined here go into the .ctors and .dtors
+   sections of the crtend.o file, and since that file is always linked in
+   last, these words naturally end up at the very ends of the two lists
+   contained in these two sections.  */
+
+#ifdef CTOR_LIST_END
+CTOR_LIST_END;
+#elif defined(__LIBGCC_CTORS_SECTION_ASM_OP__)
+/* Hack: force cc1 to switch to .data section early, so that assembling
+   __CTOR_LIST__ does not undo our behind-the-back change to .ctors.  */
+static func_ptr force_to_data[1] __attribute__ ((__used__)) = { };
+asm (__LIBGCC_CTORS_SECTION_ASM_OP__);
+STATIC func_ptr __CTOR_END__[1]
+  __attribute__((aligned(__alignof__(func_ptr))))
+  = { (func_ptr) 0 };
+#else
+STATIC func_ptr __CTOR_END__[1]
+  __attribute__((section(".ctors"), aligned(__alignof__(func_ptr))))
+  = { (func_ptr) 0 };
+#endif
+
+#ifdef DTOR_LIST_END
+DTOR_LIST_END;
+#elif defined(HIDDEN_DTOR_LIST_END)
+#ifdef __LIBGCC_DTORS_SECTION_ASM_OP__
+asm (__LIBGCC_DTORS_SECTION_ASM_OP__);
+#endif
+func_ptr __DTOR_END__[1]
+  __attribute__ ((used,
+#ifndef __LIBGCC_DTORS_SECTION_ASM_OP__
+		  section(".dtors"),
+#endif
+		  aligned(__alignof__(func_ptr)), visibility ("hidden")))
+  = { (func_ptr) 0 };
+#elif defined(__LIBGCC_DTORS_SECTION_ASM_OP__)
+asm (__LIBGCC_DTORS_SECTION_ASM_OP__);
+STATIC func_ptr __DTOR_END__[1]
+  __attribute__ ((used, aligned(__alignof__(func_ptr))))
+  = { (func_ptr) 0 };
+#else
+STATIC func_ptr __DTOR_END__[1]
+  __attribute__((used, section(".dtors"), aligned(__alignof__(func_ptr))))
+  = { (func_ptr) 0 };
+#endif
+#endif /* USE_INITFINI_ARRAY */
+
+#ifdef __LIBGCC_EH_FRAME_SECTION_NAME__
+/* Terminate the frame unwind info section with a 4byte 0 as a sentinel;
+   this would be the 'length' field in a real FDE.  */
+# if __INT_MAX__ == 2147483647
+typedef int int32;
+# elif __LONG_MAX__ == 2147483647
+typedef long int32;
+# elif __SHRT_MAX__ == 2147483647
+typedef short int32;
+# else
+#  error "Missing a 4 byte integer"
+# endif
+STATIC EH_FRAME_SECTION_CONST int32 __FRAME_END__[]
+     __attribute__ ((used, section(__LIBGCC_EH_FRAME_SECTION_NAME__),
+		     aligned(__alignof__(int32))))
+     = { 0 };
+#endif /* __LIBGCC_EH_FRAME_SECTION_NAME__ */
+
+#if USE_TM_CLONE_REGISTRY
+# ifndef HAVE_GAS_HIDDEN
+static
+# endif
+func_ptr __TMC_END__[]
+  __attribute__((used, section(".tm_clone_table"),
+		 aligned(__alignof__(void *))))
+# ifdef HAVE_GAS_HIDDEN
+  __attribute__((__visibility__ ("hidden"))) = { };
+# else
+  = { 0, 0 };
+# endif
+#endif /* USE_TM_CLONE_REGISTRY */
+
+#ifdef __LIBGCC_INIT_ARRAY_SECTION_ASM_OP__
+
+/* If we are using .init_array, there is nothing to do.  */
+
+#elif defined(__LIBGCC_INIT_SECTION_ASM_OP__)
+
+#ifdef OBJECT_FORMAT_ELF
+static void __attribute__((used))
+__do_global_ctors_aux (void)
+{
+  func_ptr *p;
+  for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--)
+    (*p) ();
+}
+
+/* Stick a call to __do_global_ctors_aux into the .init section.  */
+CRT_CALL_STATIC_FUNCTION (__LIBGCC_INIT_SECTION_ASM_OP__, __do_global_ctors_aux)
+#else  /* OBJECT_FORMAT_ELF */
+
+/* Stick the real initialization code, followed by a normal sort of
+   function epilogue at the very end of the .init section for this
+   entire root executable file or for this entire shared library file.
+
+   Note that we use some tricks here to get *just* the body and just
+   a function epilogue (but no function prologue) into the .init
+   section of the crtend.o file.  Specifically, we switch to the .text
+   section, start to define a function, and then we switch to the .init
+   section just before the body code.
+
+   Earlier on, we put the corresponding function prologue into the .init
+   section of the crtbegin.o file (which will be linked in first).
+
+   Note that we want to invoke all constructors for C++ file-scope static-
+   storage objects AFTER any other possible initialization actions which
+   may be performed by the code in the .init section contributions made by
+   other libraries, etc.  That's because those other initializations may
+   include setup operations for very primitive things (e.g. initializing
+   the state of the floating-point coprocessor, etc.) which should be done
+   before we start to execute any of the user's code.  */
+
+static void
+__do_global_ctors_aux (void)	/* prologue goes in .text section */
+{
+  asm (__LIBGCC_INIT_SECTION_ASM_OP__);
+  DO_GLOBAL_CTORS_BODY;
+  atexit (__do_global_dtors);
+}				/* epilogue and body go in .init section */
+
+FORCE_CODE_SECTION_ALIGN
+asm (__LIBGCC_TEXT_SECTION_ASM_OP__);
+
+#endif /* OBJECT_FORMAT_ELF */
+
+#elif defined(HAS_INIT_SECTION) /* ! __LIBGCC_INIT_SECTION_ASM_OP__ */
+
+extern void __do_global_ctors (void);
+
+/* This case is used by the Irix 6 port, which supports named sections but
+   not an SVR4-style .init section.  __do_global_ctors can be non-static
+   in this case because we protect it with -hidden_symbol.  */
+void
+__do_global_ctors (void)
+{
+  func_ptr *p;
+#if defined(USE_EH_FRAME_REGISTRY) || USE_TM_CLONE_REGISTRY
+  __do_global_ctors_1();
+#endif
+  for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--)
+    (*p) ();
+}
+
+#else /* ! __LIBGCC_INIT_SECTION_ASM_OP__ && ! HAS_INIT_SECTION */
+#error "What are you doing with crtstuff.c, then?"
+#endif
+
+#else /* ! CRT_BEGIN && ! CRT_END */
+#error "One of CRT_BEGIN or CRT_END must be defined."
+#endif
diff --git a/libgcc/config/msp430/t-msp430 b/libgcc/config/msp430/t-msp430
index 72ae93a8dae..17d85b6cb23 100644
--- a/libgcc/config/msp430/t-msp430
+++ b/libgcc/config/msp430/t-msp430
@@ -42,12 +42,6 @@  LIB2ADD = \
 
 HOST_LIBGCC2_CFLAGS += -Os -ffunction-sections -fdata-sections -mhwmult=none
 
-crtbegin_no_eh.o: $(srcdir)/crtstuff.c
-	$(crt_compile) -U__LIBGCC_EH_FRAME_SECTION_NAME__ -c $< -DCRT_BEGIN
-
-crtend_no_eh.o: $(srcdir)/crtstuff.c
-	$(crt_compile) -U__LIBGCC_EH_FRAME_SECTION_NAME__ -c $< -DCRT_END
-
 mpy.o: $(srcdir)/config/msp430/mpy.c
 	$(gcc_compile) $< -c
 
diff --git a/libgcc/config/msp430/t-msp430-crtstuff b/libgcc/config/msp430/t-msp430-crtstuff
new file mode 100644
index 00000000000..12307295640
--- /dev/null
+++ b/libgcc/config/msp430/t-msp430-crtstuff
@@ -0,0 +1,29 @@ 
+# Makefile fragment for building crtstuff.c for the TI MSP430 processor.
+# Copyright (C) 2011-2019 Free Software Foundation, Inc.
+# Contributed by Mitto Systems Limited.
+#
+# This file is part of GCC.
+#
+# GCC is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published
+# by the Free Software Foundation; either version 3, or (at your
+# option) any later version.
+#
+# GCC 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 General Public License for more details.
+#
+# You should have received a copy of the  GNU General Public
+# License along with GCC; see the file COPYING3.  If not see
+# <http://www.gnu.org/licenses/>.
+
+crtbegin_no_eh.o: $(srcdir)/crtstuff.c
+	$(crt_compile) $(CRTSTUFF_T_CFLAGS) -U__LIBGCC_EH_FRAME_SECTION_NAME__ -c $< -DCRT_BEGIN
+
+crtend_no_eh.o: $(srcdir)/crtstuff.c
+	$(crt_compile) $(CRTSTUFF_T_CFLAGS) -U__LIBGCC_EH_FRAME_SECTION_NAME__ -c $< -DCRT_END
+
+# Local Variables:
+# mode: Makefile
+# End:
diff --git a/libgcc/config/msp430/t-msp430-elfbare-crtstuff b/libgcc/config/msp430/t-msp430-elfbare-crtstuff
new file mode 100644
index 00000000000..560e7cebd4a
--- /dev/null
+++ b/libgcc/config/msp430/t-msp430-elfbare-crtstuff
@@ -0,0 +1,43 @@ 
+# Makefile fragment for building crtstuff for the TI MSP430 processor.
+# Copyright (C) 2019 Free Software Foundation, Inc.
+# Contributed by Mitto Systems Limited.
+#
+# This file is part of GCC.
+#
+# GCC is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published
+# by the Free Software Foundation; either version 3, or (at your
+# option) any later version.
+#
+# GCC 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 General Public License for more details.
+#
+# You should have received a copy of the  GNU General Public
+# License along with GCC; see the file COPYING3.  If not see
+# <http://www.gnu.org/licenses/>.
+
+CUSTOM_CRTSTUFF = yes
+
+# Things will break if __cxa_atexit is enabled and the declaration of
+# __dso_handle is removed.  However, there are checks to ensure this Makefile
+# fragment does not get used if __cxa_atexit has been enabled at configure
+# time.
+MSP430_CRTSTUFF_FLAGS = -DMSP430_CRTSTUFF_NO_DSO_HANDLE
+
+crtbegin_no_eh.o: $(srcdir)/config/msp430/msp430-elfbare-crtstuff.c
+	$(crt_compile) $(CRTSTUFF_T_CFLAGS) $(MSP430_CRTSTUFF_FLAGS) -U__LIBGCC_EH_FRAME_SECTION_NAME__ -c $< -DCRT_BEGIN
+
+crtend_no_eh.o: $(srcdir)/config/msp430/msp430-elfbare-crtstuff.c
+	$(crt_compile) $(CRTSTUFF_T_CFLAGS) $(MSP430_CRTSTUFF_FLAGS) -U__LIBGCC_EH_FRAME_SECTION_NAME__ -c $< -DCRT_END
+
+crtbegin.o: $(srcdir)/config/msp430/msp430-elfbare-crtstuff.c
+	$(crt_compile) $(CRTSTUFF_T_CFLAGS) $(MSP430_CRTSTUFF_FLAGS) $(CRTSTUFF_T_CFLAGS) -c $< -DCRT_BEGIN
+
+crtend.o: $(srcdir)/config/msp430/msp430-elfbare-crtstuff.c
+	$(crt_compile) $(CRTSTUFF_T_CFLAGS) $(MSP430_CRTSTUFF_FLAGS) $(CRTSTUFF_T_CFLAGS) -c $< -DCRT_END
+
+# Local Variables:
+# mode: Makefile
+# End:
diff --git a/libgcc/configure b/libgcc/configure
index 117e9c97e57..97cbad3be56 100755
--- a/libgcc/configure
+++ b/libgcc/configure
@@ -4964,6 +4964,15 @@  if test "$enable_tm_clone_registry" = no; then
   use_tm_clone_registry=-DUSE_TM_CLONE_REGISTRY=0
 fi
 
+else
+
+use_tm_clone_registry=
+case $target in
+  msp430*elfbare)
+   use_tm_clone_registry=-DUSE_TM_CLONE_REGISTRY=0
+   ;;
+esac
+
 fi
 
 
diff --git a/libgcc/configure.ac b/libgcc/configure.ac
index f63c5e736e5..2d22f05486d 100644
--- a/libgcc/configure.ac
+++ b/libgcc/configure.ac
@@ -268,6 +268,14 @@  use_tm_clone_registry=
 if test "$enable_tm_clone_registry" = no; then
   use_tm_clone_registry=-DUSE_TM_CLONE_REGISTRY=0
 fi
+],
+[
+use_tm_clone_registry=
+case $target in
+  msp430*elfbare)
+   use_tm_clone_registry=-DUSE_TM_CLONE_REGISTRY=0
+   ;;
+esac
 ])
 AC_SUBST([use_tm_clone_registry])
 
-- 
2.17.1