OpenRISC port

Hello,

As you can see this is v4 of the OpenRISC port patch series, I just want to mention that there are a few things pointed out during the v3 review that I have not fixed, and do not plan before pushing upstream. These are either because I didn't feel they made the code easier to read or they were things that could wait unil after upstreaming. These include:

(not changed)
- libgcc !cmov 1cyc improvements suggested by Richard
- gcc eliminations refactorings suggested by Segher
- leaving out empty constraint strings suggested by Segher
- implementing TARGET_ISNS_COST suggested by Segher

Please let me know if you have concerns; now onto the patches:

Changes Since v3:
- Fix tabs formatting pointed out by Segher
- Fix comment formatting and typos pointed out by Segher
- Fix for sign/zero extention login in md file from Richard
- Remove usages of ATTRIBUTE_UNUSED suggested by Segher
- Remove need for init/fini, removing crti/n.S files
- Add support for -static-pie in LINK_SPEC suggsted by Szabolcs

Changes Since v2:
- Add RTEMS patches from Joel Sherrill
- Disable t-softfp-excl as suggsted by Joseph Myers
- Add new architecture flags needed to run on real FPGA's found in testing
* -mror - enable l.ror (rotate right)
* -mshftimm - enable shift/rorate by immediate instructions
- Binutils requirements are now in upstream git

Changes Since v1:
- Document options in invoke.texi suggested by Joseph Myers
- Remove obsolete/incorrect macros suggested by Joseph Myers
- Documented or1k.c functions as requested by Jeff Law
- Add epilogue barriers suggested by Jeff Law
- Define SPECULATION_SAFE_VALUE suggested by Jeff Law
- Switch to init/fini array suggested by Richard Henderson
- Define and document multilib flags to enable disable instructions only available on some CPU cores as requested on OpenRISC mailing list.

Since February this year I have been working on an OpenRISC clean room rewrite.

http://stffrdhrn.github.io/software/embedded/openrisc/2018/02/03/openrisc_gcc_rewrite.html

As per the article, the old port had issues with some of the owners signing over FSF copyright. To get around this I discussed options with the group and in the end I opted for a clean room rewrite.

The new code base has been written by me with lots of help from Richard Henderson. I trust that both of us have our FSF GCC copyright's in place.

# Testing

We have been running the GCC testsuite with newlib and musl libc. The results are good. See results published in a test build/release here:

- https://github.com/stffrdhrn/gcc/releases/tag/or1k-9.0.0-20181106

# Building

To build this requires the latest binutils upstream master i.e. 2.31.52. Also, due to removing need for init and fini it requires the latest changes on newlib master.

-Stafford

Stafford Horne (3):
or1k: libgcc: initial support for openrisc
or1k: testsuite: initial support for openrisc
or1k: gcc: initial support for openrisc

 gcc/common/config/or1k/or1k-common.c          |   41 +
 gcc/config.gcc                                |   45 +
 gcc/config/or1k/constraints.md                |   55 +
 gcc/config/or1k/elf.h                         |   42 +
 gcc/config/or1k/elf.opt                       |   33 +
 gcc/config/or1k/linux.h                       |   45 +
 gcc/config/or1k/or1k-protos.h                 |   38 +
 gcc/config/or1k/or1k.c                        | 2183 +++++++++++++++++
 gcc/config/or1k/or1k.h                        |  392 +++
 gcc/config/or1k/or1k.md                       |  897 +++++++
 gcc/config/or1k/or1k.opt                      |   67 +
 gcc/config/or1k/predicates.md                 |   84 +
 gcc/config/or1k/rtems.h                       |   30 +
 gcc/config/or1k/t-or1k                        |   22 +
 gcc/config/or1k/t-rtems                       |    3 +
 gcc/configure                                 |   12 +
 gcc/configure.ac                              |   12 +
 gcc/doc/install.texi                          |   19 +
 gcc/doc/invoke.texi                           |   68 +
 gcc/doc/md.texi                               |   25 +
 .../gcc.c-torture/execute/20101011-1.c        |    3 +
 gcc/testsuite/gcc.dg/20020312-2.c             |    2 +
 gcc/testsuite/gcc.dg/attr-alloc_size-11.c     |    4 +-
 gcc/testsuite/gcc.dg/builtin-apply2.c         |    2 +-
 gcc/testsuite/gcc.dg/nop.h                    |    2 +
 .../torture/stackalign/builtin-apply-2.c      |    2 +-
 gcc/testsuite/gcc.dg/tree-ssa/20040204-1.c    |    2 +-
 gcc/testsuite/gcc.dg/tree-ssa/reassoc-33.c    |    2 +-
 gcc/testsuite/gcc.dg/tree-ssa/reassoc-34.c    |    2 +-
 gcc/testsuite/gcc.dg/tree-ssa/reassoc-35.c    |    2 +-
 gcc/testsuite/gcc.dg/tree-ssa/reassoc-36.c    |    2 +-
 gcc/testsuite/gcc.target/or1k/args-1.c        |   19 +
 gcc/testsuite/gcc.target/or1k/args-2.c        |   15 +
 gcc/testsuite/gcc.target/or1k/cmov-1.c        |    8 +
 gcc/testsuite/gcc.target/or1k/cmov-2.c        |    9 +
 gcc/testsuite/gcc.target/or1k/div-mul-1.c     |    9 +
 gcc/testsuite/gcc.target/or1k/div-mul-2.c     |    9 +
 gcc/testsuite/gcc.target/or1k/or1k.exp        |   41 +
 gcc/testsuite/gcc.target/or1k/return-1.c      |   10 +
 gcc/testsuite/gcc.target/or1k/return-2.c      |   19 +
 gcc/testsuite/gcc.target/or1k/return-3.c      |   19 +
 gcc/testsuite/gcc.target/or1k/return-4.c      |   19 +
 gcc/testsuite/gcc.target/or1k/ror-1.c         |    8 +
 gcc/testsuite/gcc.target/or1k/ror-2.c         |    9 +
 gcc/testsuite/gcc.target/or1k/ror-3.c         |    8 +
 gcc/testsuite/gcc.target/or1k/shftimm-1.c     |    8 +
 gcc/testsuite/gcc.target/or1k/shftimm-2.c     |    8 +
 gcc/testsuite/gcc.target/or1k/sibcall-1.c     |   18 +
 gcc/testsuite/lib/target-supports.exp         |    1 +
 libgcc/config.host                            |   12 +
 libgcc/config/or1k/lib1funcs.S                |  222 ++
 libgcc/config/or1k/linux-unwind.h             |   87 +
 libgcc/config/or1k/sfp-machine.h              |   54 +
 libgcc/config/or1k/t-or1k                     |   22 +
 54 files changed, 4763 insertions(+), 9 deletions(-)
 create mode 100644 gcc/common/config/or1k/or1k-common.c
 create mode 100644 gcc/config/or1k/constraints.md
 create mode 100644 gcc/config/or1k/elf.h
 create mode 100644 gcc/config/or1k/elf.opt
 create mode 100644 gcc/config/or1k/linux.h
 create mode 100644 gcc/config/or1k/or1k-protos.h
 create mode 100644 gcc/config/or1k/or1k.c
 create mode 100644 gcc/config/or1k/or1k.h
 create mode 100644 gcc/config/or1k/or1k.md
 create mode 100644 gcc/config/or1k/or1k.opt
 create mode 100644 gcc/config/or1k/predicates.md
 create mode 100644 gcc/config/or1k/rtems.h
 create mode 100644 gcc/config/or1k/t-or1k
 create mode 100644 gcc/config/or1k/t-rtems
 create mode 100644 gcc/testsuite/gcc.target/or1k/args-1.c
 create mode 100644 gcc/testsuite/gcc.target/or1k/args-2.c
 create mode 100644 gcc/testsuite/gcc.target/or1k/cmov-1.c
 create mode 100644 gcc/testsuite/gcc.target/or1k/cmov-2.c
 create mode 100644 gcc/testsuite/gcc.target/or1k/div-mul-1.c
 create mode 100644 gcc/testsuite/gcc.target/or1k/div-mul-2.c
 create mode 100644 gcc/testsuite/gcc.target/or1k/or1k.exp
 create mode 100644 gcc/testsuite/gcc.target/or1k/return-1.c
 create mode 100644 gcc/testsuite/gcc.target/or1k/return-2.c
 create mode 100644 gcc/testsuite/gcc.target/or1k/return-3.c
 create mode 100644 gcc/testsuite/gcc.target/or1k/return-4.c
 create mode 100644 gcc/testsuite/gcc.target/or1k/ror-1.c
 create mode 100644 gcc/testsuite/gcc.target/or1k/ror-2.c
 create mode 100644 gcc/testsuite/gcc.target/or1k/ror-3.c
 create mode 100644 gcc/testsuite/gcc.target/or1k/shftimm-1.c
 create mode 100644 gcc/testsuite/gcc.target/or1k/shftimm-2.c
 create mode 100644 gcc/testsuite/gcc.target/or1k/sibcall-1.c
 create mode 100644 libgcc/config/or1k/lib1funcs.S
 create mode 100644 libgcc/config/or1k/linux-unwind.h
 create mode 100644 libgcc/config/or1k/sfp-machine.h
 create mode 100644 libgcc/config/or1k/t-or1k

2.17.2