Recent Darwin versions place contraints on the use of run paths
specified in environment variables.  This breaks some assumptions
in the GCC build.

This change allows the user to configure a Darwin build to use
'@rpath/libraryname.dylib' in library names and then to add an
embedded runpath to executables (and libraries with dependents).

The embedded runpath is added by default unless the user adds
'-nodefaultrpaths' to the link line.

For an installed compiler, it means that any executable built with
that compiler will reference the runtimes installed with the
compiler (equivalent to hard-coding the library path into the name
of the library).

During build-time configurations  any "-B" entries will be added to
the runpath thus the newly-built libraries will be found by exes.

Since the install name is set in libtool, that decision needs to be
available here (but might also cause dependent ones in Makefiles,
so we need to export a conditional).

This facility is not available for Darwin 8 or earlier, however the
existing environment variable runpath does work there.

We default this on for systems where the external DYLD_LIBRARY_PATH
does not work and off for Darwin 8 or earlier.  For systems that can
use either method, if the value is unset, we use the default (which
is currently DYLD_LIBRARY_PATH).

ChangeLog:

	* configure: Regenerate.
	* configure.ac: Do not add default runpaths to GCC exes
	when we are building -static-libstdc++/-static-libgcc (the
	default).
	* libtool.m4: Add 'enable-darwin-at-runpath'.  Act  on the
	enable flag to alter Darwin libraries to use @rpath names.

gcc/ChangeLog:

	* aclocal.m4: Regenerate.
	* configure: Regenerate.
	* configure.ac: Handle Darwin rpaths.
	* config/darwin.h: Handle Darwin rpaths.
	* config/darwin.opt: Handle Darwin rpaths.
	* Makefile.in:  Handle Darwin rpaths.

gcc/ada/ChangeLog:

	* gcc-interface/Makefile.in: Handle Darwin rpaths.

gcc/jit/ChangeLog:
	* Make-lang.in: Handle Darwin rpaths.

libatomic/ChangeLog:

	* Makefile.am: Handle Darwin rpaths.
	* Makefile.in: Regenerate.
	* configure: Regenerate.
	* configure.ac: Handle Darwin rpaths.

libbacktrace/ChangeLog:

	* configure: Regenerate.
	* configure.ac: Handle Darwin rpaths.

libcc1/ChangeLog:

	* configure: Regenerate.

libffi/ChangeLog:

	* Makefile.am: Handle Darwin rpaths.
	* Makefile.in: Regenerate.
	* configure: Regenerate.

libgcc/ChangeLog:

	* config/t-slibgcc-darwin: Generate libgcc_s
	with an @rpath name.
	* config.host: Handle Darwin rpaths.

libgfortran/ChangeLog:

	* Makefile.am: Handle Darwin rpaths.
	* Makefile.in: Regenerate.
	* configure: Regenerate.
	* configure.ac: Handle Darwin rpaths

libgm2/ChangeLog:

	* Makefile.am: Handle Darwin rpaths.
	* Makefile.in: Regenerate.
	* aclocal.m4: Regenerate.
	* configure: Regenerate.
	* configure.ac: Handle Darwin rpaths.
	* libm2cor/Makefile.am: Handle Darwin rpaths.
	* libm2cor/Makefile.in: Regenerate.
	* libm2iso/Makefile.am: Handle Darwin rpaths.
	* libm2iso/Makefile.in: Regenerate.
	* libm2log/Makefile.am: Handle Darwin rpaths.
	* libm2log/Makefile.in: Regenerate.
	* libm2min/Makefile.am: Handle Darwin rpaths.
	* libm2min/Makefile.in: Regenerate.
	* libm2pim/Makefile.am: Handle Darwin rpaths.
	* libm2pim/Makefile.in: Regenerate.

libgomp/ChangeLog:

	* Makefile.am: Handle Darwin rpaths.
	* Makefile.in: Regenerate.
	* configure: Regenerate.
	* configure.ac: Handle Darwin rpaths

libitm/ChangeLog:

	* Makefile.am: Handle Darwin rpaths.
	* Makefile.in: Regenerate.
	* configure: Regenerate.
	* configure.ac: Handle Darwin rpaths.

libobjc/ChangeLog:

	* configure: Regenerate.
	* configure.ac: Handle Darwin rpaths.

libphobos/ChangeLog:

	* configure: Regenerate.
	* configure.ac: Handle Darwin rpaths.
	* libdruntime/Makefile.am: Handle Darwin rpaths.
	* libdruntime/Makefile.in: Regenerate.
	* src/Makefile.am: Handle Darwin rpaths.
	* src/Makefile.in: Regenerate.

libquadmath/ChangeLog:

	* Makefile.am: Handle Darwin rpaths.
	* Makefile.in: Regenerate.
	* configure: Regenerate.
	* configure.ac: Handle Darwin rpaths.

libsanitizer/ChangeLog:

	* asan/Makefile.am: Handle Darwin rpaths.
	* asan/Makefile.in: Regenerate.
	* configure: Regenerate.
	* hwasan/Makefile.am: Handle Darwin rpaths.
	* hwasan/Makefile.in: Regenerate.
	* lsan/Makefile.am: Handle Darwin rpaths.
	* lsan/Makefile.in: Regenerate.
	* tsan/Makefile.am: Handle Darwin rpaths.
	* tsan/Makefile.in: Regenerate.
	* ubsan/Makefile.am: Handle Darwin rpaths.
	* ubsan/Makefile.in: Regenerate.

libssp/ChangeLog:

	* Makefile.am: Handle Darwin rpaths.
	* Makefile.in: Regenerate.
	* configure: Regenerate.
	* configure.ac: Handle Darwin rpaths.

libstdc++-v3/ChangeLog:

	* configure: Regenerate.
	* configure.ac: Handle Darwin rpaths.
	* src/Makefile.am: Handle Darwin rpaths.
	* src/Makefile.in: Regenerate.

libvtv/ChangeLog:

	* configure: Regenerate.
	* configure.ac: Handle Darwin rpaths.

lto-plugin/ChangeLog:
	* configure: Regenerate.
	* configure.ac: Handle Darwin rpaths.

zlib/ChangeLog:
	* configure: Regenerate.
	* configure.ac: Handle Darwin rpaths.

This provides a spec to insert "-rpath DDD" for each DDD corresponding
to a compiler startfile directory.  This allows a target to use @rpath
as the install path for libraries, and have the compiler provide the
necessary rpath to handle this.

Embed real paths, not relative ones.

We embed a runpath for every path in which libraries might be found.  This
change ensures that we embed the actual real path and not a relative one from
the compiler's version-specific directory.

e.g.
/opt/distro/gcc-11-3Dr0/lib

instead of:
/opt/distro/gcc-11-3Dr0/lib/gcc/x86_64-apple-darwin19/11.3.0/../../..

This ensures that if we install, for example, 11.4.0 (and delete the 11.3.0
installation) exes built by 11.3 would continue to function (providing, of course
that 11.4 does not bump any SO names).

gcc/ChangeLog:
	* gcc.cc (RUNPATH_OPTION): New.
	(do_spec_1): Provide '%P' as a spec to insert rpaths for
	each compiler startfile path.

Add support for heap-based trampolines on x86_64-linux, aarch64-linux,
and x86_64-darwin. Implement the __builtin_nested_func_ptr_created and
__builtin_nested_func_ptr_deleted functions for these targets.

Co-Authored-By: Maxim Blinov <maxim.blinov@embecosm.com>
Co-Authored-By: Iain Sandoe <iain@sandoe.co.uk>
Co-Authored-By: Francois-Xavier Coudert <fxcoudert@gcc.gnu.org>

libgcc/ChangeLog:

	* libgcc2.h (__builtin_nested_func_ptr_created): Declare.
	(__builtin_nested_func_ptr_deleted): Declare.
	* libgcc-std.ver.in: Add the new symbols.
	* config/aarch64/heap-trampoline.c: Implement heap-based
	trampolines for aarch64.
	* config/aarch64/t-heap-trampoline: Add rule to build
	config/aarch64/heap-trampoline.c
	* config/i386/heap-trampoline.c: Implement heap-based
	trampolines for x86_64.
	* config/i386/t-heap-trampoline: Add rule to build
	config/i386/heap-trampoline.cc
	* config.host: Handle --enable-heap-trampolines on
	x86_64-*-linux*, aarch64-*-linux*, x86_64-*-darwin*.

Enable -ftrampoline-impl=heap by default if we are on macOS 11
or later.

Co-Authored-By: Maxim Blinov <maxim.blinov@embecosm.com>
Co-Authored-By: Francois-Xavier Coudert <fxcoudert@gcc.gnu.org>
Co-Authored-By: Iain Sandoe <iain@sandoe.co.uk>

gcc/ChangeLog:

	* config.gcc: Default to heap trampolines on macOS 11 and above.
	* config/i386/darwin.h: Define X86_CUSTOM_FUNCTION_TEST.
	* config/i386/i386.h: Define X86_CUSTOM_FUNCTION_TEST.
	* config/i386/i386.cc: Use X86_CUSTOM_FUNCTION_TEST.

Generate heap-based nested function trampolines

Add support for allocating nested function trampolines on an
executable heap rather than on the stack. This is motivated by targets
such as AArch64 Darwin, which globally prohibit executing code on the
stack.

The target-specific routines for allocating and writing trampolines are
to be provided in libgcc.

The gcc flag -ftrampoline-impl controls whether to generate code
that instantiates trampolines on the stack, or to emit calls to
__builtin_nested_func_ptr_created and
__builtin_nested_func_ptr_deleted. Note that this flag is completely
independent of libgcc: If libgcc is for any reason missing those
symbols, you will get a link failure.

This implementation imposes some implicit restrictions as compared to
stack trampolines. longjmp'ing back to a state before a trampoline was
created will cause us to skip over the corresponding
__builtin_nested_func_ptr_deleted, which will leak trampolines
starting from the beginning of the linked list of allocated
trampolines. There may be scope for instrumenting longjmp/setjmp to
trigger cleanups of trampolines.

Co-Authored-By: Maxim Blinov <maxim.blinov@embecosm.com>
Co-Authored-By: Iain Sandoe <iain@sandoe.co.uk>
Co-Authored-By: Francois-Xavier Coudert <fxcoudert@gcc.gnu.org>

gcc/ChangeLog:

	* builtins.def (BUILT_IN_NESTED_PTR_CREATED): Define.
	(BUILT_IN_NESTED_PTR_DELETED): Ditto.
	* common.opt (ftrampoline-impl): Add option to control
	generation of trampoline instantiation (heap or stack).
	* coretypes.h: Define enum trampoline_impl.
	* tree-nested.cc (convert_tramp_reference_op): Don't bother calling
	__builtin_adjust_trampoline for heap trampolines.
	(finalize_nesting_tree_1): Emit calls to
	__builtin_nested_...{created,deleted} if we're generating with
	-ftrampoline-impl=heap.
	* tree.cc (build_common_builtin_nodes): Build
	__builtin_nested_...{created,deleted}.
	* doc/invoke.texi (-ftrampoline-impl): Document.

According to the ratified privileged specification (version 20211203),
it says:

> The hypervisor extension depends on an "I" base integer ISA with 32 x
> registers (RV32I or RV64I), not RV32E, which has only 16 x registers.

Also in the latest draft, it also prohibits RV64E with the 'H' extension.
This commit prohibits the combination of 'E' and 'H' extensions.

gcc/ChangeLog:

	* common/config/riscv/riscv-common.cc (riscv_subset_list::parse):
	Prohibit 'E' and 'H' combinations.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/arch-26.c: New test.

Since this extension is ratified, it now has the version number 1.0.

Reference:
<https://github.com/riscv/riscv-isa-manual/pull/1096>

gcc/ChangeLog:

	* common/config/riscv/riscv-common.cc (riscv_ext_version_table):
	Change version number of the 'Zfa' extension to 1.0.

This splits out the activate-the-union-member-for-constexpr logic from
_M_use_local_data, so that it can be used separately in cases that don't
need to use std::pointer_traits<pointer>::pointer_to to obtain the
return value.

This leaves only three uses of _M_use_local_data() which are all of the
same form:

  __s._M_data(_M_use_local_data());
  __s._M_set_length(0);

We could remove _M_use_local_data() and change those three places to use
a new _M_reset() function that does:

  _M_init_local_buf();
  _M_data(_M_local_data());
  _M_set_length(0);

This is left for a future change.

libstdc++-v3/ChangeLog:

	* include/bits/basic_string.h (_M_init_local_buf()): New
	function.
	(_M_use_local_data()): Use _M_init_local_buf.
	(basic_string(), basic_string(const Alloc&))
	(basic_string(basic_string&&))
	(basic_string(basic_string&&, const Alloc&)): Use
	_M_init_local_buf instead of _M_use_local_data().
	* include/bits/basic_string.tcc (swap(basic_string&))
	(_M_construct(InIter, InIter, input_iterator_tag))
	(_M_construct(InIter, InIter, forward_iterator_tag))
	(_M_construct(size_type, CharT), reserve()): Likewise.

This patch adds a small workaround that avoids declaring constrained
friends when compiling with Clang, instead making some members public.
MSVC's standard library has implemented a similar workaround.

Signed-off-by: Benjamin Brock <brock@cs.berkeley.edu>

libstdc++-v3/ChangeLog:

	* include/std/ranges (zip_view, adjacent_view): Implement
	workaround for LLVM-61763.

We can test codecvt::length() with the same data that we test
codecvt::in(). For each call of in() we add another call to length().
Some additional small cosmentic changes are applied.

libstdc++-v3/ChangeLog:

	* testsuite/22_locale/codecvt/codecvt_unicode.h: Test length()

Fix indentation.

libstdc++-v3/ChangeLog:

	* include/bits/fs_dir.h (operator==(default_sentinel_t)): Fix
	indentation.

gcc/testsuite/

	* gcc.c-torture/compile/20000403-1.c: Compile with -std=gnu89.
	* gcc.c-torture/compile/20000511-1.c: Likewise.
	* gcc.c-torture/compile/20000804-1.c: Likewise.
	* gcc.c-torture/compile/20020418-1.c: Likewise.
	* gcc.c-torture/compile/20020927-1.c: Likewise.
	* gcc.c-torture/compile/20030109-1.c: Likewise.
	* gcc.c-torture/compile/20030224-1.c: Likewise.
	* gcc.c-torture/compile/20030415-1.c: Likewise.
	* gcc.c-torture/compile/20030612-1.c: Likewise.
	* gcc.c-torture/compile/20030917-1.c: Likewise.
	* gcc.c-torture/compile/20031113-1.c: Likewise.
	* gcc.c-torture/compile/20031220-2.c: Likewise.
	* gcc.c-torture/compile/20040309-1.c: Likewise.
	* gcc.c-torture/compile/20040310-1.c: Likewise.
	* gcc.c-torture/compile/20040317-3.c: Likewise.
	* gcc.c-torture/compile/20040817-1.c: Likewise.
	* gcc.c-torture/compile/20091215-1.c: Likewise.
	* gcc.c-torture/compile/86.c: Likewise.
	* gcc.c-torture/compile/900216-1.c: Likewise.
	* gcc.c-torture/compile/900313-1.c: Likewise.
	* gcc.c-torture/compile/900407-1.c: Likewise.
	* gcc.c-torture/compile/900516-1.c: Likewise.
	* gcc.c-torture/compile/920409-2.c: Likewise.
	* gcc.c-torture/compile/920415-1.c: Likewise.
	* gcc.c-torture/compile/920428-1.c: Likewise.
	* gcc.c-torture/compile/920428-5.c: Likewise.
	* gcc.c-torture/compile/920428-7.c: Likewise.
	* gcc.c-torture/compile/920501-1.c: Likewise.
	* gcc.c-torture/compile/920501-13.c: Likewise.
	* gcc.c-torture/compile/920501-15.c: Likewise.
	* gcc.c-torture/compile/920501-16.c: Likewise.
	* gcc.c-torture/compile/920501-18.c: Likewise.
	* gcc.c-torture/compile/920501-20.c: Likewise.
	* gcc.c-torture/compile/920501-6.c: Likewise.
	* gcc.c-torture/compile/920501-7.c: Likewise.
	* gcc.c-torture/compile/920502-1.c: Likewise.
	* gcc.c-torture/compile/920502-2.c: Likewise.
	* gcc.c-torture/compile/920520-1.c: Likewise.
	* gcc.c-torture/compile/920521-1.c: Likewise.
	* gcc.c-torture/compile/920608-1.c: Likewise.
	* gcc.c-torture/compile/920617-1.c: Likewise.
	* gcc.c-torture/compile/920617-2.c: Likewise.
	* gcc.c-torture/compile/920625-1.c: Likewise.
	* gcc.c-torture/compile/920625-2.c: Likewise.
	* gcc.c-torture/compile/920626-1.c: Likewise.
	* gcc.c-torture/compile/920706-1.c: Likewise.
	* gcc.c-torture/compile/920710-2.c: Likewise.
	* gcc.c-torture/compile/920723-1.c: Likewise.
	* gcc.c-torture/compile/920808-1.c: Likewise.
	* gcc.c-torture/compile/920809-1.c: Likewise.
	* gcc.c-torture/compile/920817-1.c: Likewise.
	* gcc.c-torture/compile/920831-1.c: Likewise.
	* gcc.c-torture/compile/920917-1.c: Likewise.
	* gcc.c-torture/compile/920928-2.c: Likewise.
	* gcc.c-torture/compile/920928-5.c: Likewise.
	* gcc.c-torture/compile/921012-1.c: Likewise.
	* gcc.c-torture/compile/921021-1.c: Likewise.
	* gcc.c-torture/compile/921024-1.c: Likewise.
	* gcc.c-torture/compile/921103-1.c: Likewise.
	* gcc.c-torture/compile/921109-1.c: Likewise.
	* gcc.c-torture/compile/921111-1.c: Likewise.
	* gcc.c-torture/compile/921116-2.c: Likewise.
	* gcc.c-torture/compile/921118-1.c: Likewise.
	* gcc.c-torture/compile/921202-1.c: Likewise.
	* gcc.c-torture/compile/921202-2.c: Likewise.
	* gcc.c-torture/compile/921203-1.c: Likewise.
	* gcc.c-torture/compile/921203-2.c: Likewise.
	* gcc.c-torture/compile/921206-1.c: Likewise.
	* gcc.c-torture/compile/930109-1.c: Likewise.
	* gcc.c-torture/compile/930111-1.c: Likewise.
	* gcc.c-torture/compile/930117-1.c: Likewise.
	* gcc.c-torture/compile/930118-1.c: Likewise.
	* gcc.c-torture/compile/930120-1.c: Likewise.
	* gcc.c-torture/compile/930217-1.c: Likewise.
	* gcc.c-torture/compile/930325-1.c: Likewise.
	* gcc.c-torture/compile/930411-1.c: Likewise.
	* gcc.c-torture/compile/930427-2.c: Likewise.
	* gcc.c-torture/compile/930503-2.c: Likewise.
	* gcc.c-torture/compile/930506-2.c: Likewise.
	* gcc.c-torture/compile/930513-2.c: Likewise.
	* gcc.c-torture/compile/930530-1.c: Likewise.
	* gcc.c-torture/compile/930602-1.c: Likewise.
	* gcc.c-torture/compile/930618-1.c: Likewise.
	* gcc.c-torture/compile/930623-1.c: Likewise.
	* gcc.c-torture/compile/931003-1.c: Likewise.
	* gcc.c-torture/compile/931013-1.c: Likewise.
	* gcc.c-torture/compile/931013-2.c: Likewise.
	* gcc.c-torture/compile/931102-2.c: Likewise.
	* gcc.c-torture/compile/931203-1.c: Likewise.
	* gcc.c-torture/compile/940718-1.c: Likewise.
	* gcc.c-torture/compile/941014-1.c: Likewise.
	* gcc.c-torture/compile/941014-2.c: Likewise.
	* gcc.c-torture/compile/941014-3.c: Likewise.
	* gcc.c-torture/compile/941014-4.c: Likewise.
	* gcc.c-torture/compile/941111-1.c: Likewise.
	* gcc.c-torture/compile/941113-1.c: Likewise.
	* gcc.c-torture/compile/950124-1.c: Likewise.
	* gcc.c-torture/compile/950329-1.c: Likewise.
	* gcc.c-torture/compile/950612-1.c: Likewise.
	* gcc.c-torture/compile/950618-1.c: Likewise.
	* gcc.c-torture/compile/950719-1.c: Likewise.
	* gcc.c-torture/compile/950910-1.c: Likewise.
	* gcc.c-torture/compile/950922-1.c: Likewise.
	* gcc.c-torture/compile/951106-1.c: Likewise.
	* gcc.c-torture/compile/951222-1.c: Likewise.
	* gcc.c-torture/compile/960106-1.c: Likewise.
	* gcc.c-torture/compile/960319-1.c: Likewise.
	* gcc.c-torture/compile/960829-1.c: Likewise.
	* gcc.c-torture/compile/970206-1.c: Likewise.
	* gcc.c-torture/compile/980825-1.c: Likewise.
	* gcc.c-torture/compile/990829-1.c: Likewise.
	* gcc.c-torture/compile/991213-2.c: Likewise.

Given we have code like below:

typedef char vnx16i __attribute__ ((vector_size (16)));

vnx16i __attribute__ ((noinline, noclone))
test (vnx16i x, vnx16i y)
{
  return __builtin_shufflevector (x, y, 11, 12, 13, 14, 11, 12, 13, 14,
                                        11, 12, 13, 14, 11, 12, 13, 14);
}

It can perform the auto vectorization when

-march=rv64gcv_zvl1024b --param=riscv-autovec-preference=fixed-vlmax

but cannot when

-march=rv64gcv_zvl2048b --param=riscv-autovec-preference=fixed-vlmax

The reason comes from the miniaml machine mode of QI is RVVMF8QI, which
is 1024 / 8 = 128 bits, aka the size of VNx16QI. When we set zvl2048b,
the bit size of RVVMFQI is 2048 / 8 = 256, which is not matching the
bit size of VNx16QI (128 bits).

Thus, this patch would like to enable the VLS mode for such case, aka
VNx16QI vls mode for zvl2048b.

Before this patch:
test:
  srli    a4,a1,40
  andi    a4,a4,0xff
  srli    a3,a1,32
  srli    a5,a1,48
  slli    a0,a4,8
  andi    a3,a3,0xff
  andi    a5,a5,0xff
  slli    a2,a5,16
  or      a0,a3,a0
  srli    a1,a1,56
  or      a0,a0,a2
  slli    a2,a1,24
  slli    a3,a3,32
  or      a0,a0,a2
  slli    a4,a4,40
  or      a0,a0,a3
  slli    a5,a5,48
  or      a0,a0,a4
  or      a0,a0,a5
  slli    a1,a1,56
  or      a0,a0,a1
  mv      a1,a0
  ret

After this patch:
test:
  vsetivli        zero,16,e8,mf8,ta,ma
  vle8.v  v2,0(a1)
  vsetivli        zero,4,e32,mf2,ta,ma
  vrgather.vi     v1,v2,3
  vsetivli        zero,16,e8,mf8,ta,ma
  vse8.v  v1,0(a0)
  ret

	PR target/111857

gcc/ChangeLog:

	* config/riscv/riscv-opts.h (TARGET_VECTOR_VLS): Remove.
	* config/riscv/riscv-protos.h (vls_mode_valid_p): New func decl.
	* config/riscv/riscv-v.cc (autovectorize_vector_modes): Replace
	macro reference to func.
	(vls_mode_valid_p): New func impl for vls mode valid or not.
	* config/riscv/riscv-vector-switch.def (VLS_ENTRY): Replace
	macro reference to func.
	* config/riscv/vector-iterators.md: Ditto.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/rvv/autovec/vls-vlmax/perm-4.c: Adjust checker.
	* gcc.target/riscv/rvv/autovec/vls/def.h: Add help define.
	* gcc.target/riscv/rvv/autovec/vls-vlmax/pr111857-0.c: New test.
	* gcc.target/riscv/rvv/autovec/vls-vlmax/pr111857-1.c: New test.
	* gcc.target/riscv/rvv/autovec/vls-vlmax/pr111857-2.c: New test.
	* gcc.target/riscv/rvv/autovec/vls-vlmax/pr111857-3.c: New test.
	* gcc.target/riscv/rvv/autovec/vls-vlmax/pr111857-4.c: New test.
	* gcc.target/riscv/rvv/autovec/vls-vlmax/pr111857-5.c: New test.
	* gcc.target/riscv/rvv/autovec/vls-vlmax/pr111857-6.c: New test.

Signed-off-by: Pan Li <pan2.li@intel.com>

This patch is the backend piece of a solution to PRs 101955 and 106245,
that adds a define_insn_and_split to the i386 backend, to perform sign
extension of a single (least significant) bit using and $1 then neg.

Previously, (x<<31)>>31 would be generated as

        sall    $31, %eax	// 3 bytes
        sarl    $31, %eax	// 3 bytes

with this patch the backend now generates:

        andl    $1, %eax	// 3 bytes
        negl    %eax		// 2 bytes

Not only is this smaller in size, but microbenchmarking confirms
that it's a performance win on both Intel and AMD; Intel sees only a
2% improvement (perhaps just a size effect), but AMD sees a 7% win.

2023-10-21  Roger Sayle  <roger@nextmovesoftware.com>
	    Uros Bizjak  <ubizjak@gmail.com>

gcc/ChangeLog
	PR middle-end/101955
	PR tree-optimization/106245
	* config/i386/i386.md (*extv<mode>_1_0): New define_insn_and_split.

gcc/testsuite/ChangeLog
	PR middle-end/101955
	PR tree-optimization/106245
	* gcc.target/i386/pr106245-2.c: New test case.
	* gcc.target/i386/pr106245-3.c: New 32-bit test case.
	* gcc.target/i386/pr106245-4.c: New 64-bit test case.
	* gcc.target/i386/pr106245-5.c: Likewise.

In my implementation of P0929 I treated a conversion to an rvalue of
abstract class type as a bad conversion, but that's still too soon to check
it; we need to wait until we're done with overload resolution.

gcc/cp/ChangeLog:

	* call.cc (implicit_conversion_1): Rename...
	(implicit_conversion): ...to this.  Remove the old wrapper.

gcc/testsuite/ChangeLog:

	* g++.dg/template/sfinae-dr657.C: Adjust.

This test doesn't break as expected with implicit constexpr.

gcc/testsuite/ChangeLog:

	* g++.dg/cpp1y/constexpr-diag1.C: Add -fno-implicit-constexpr.

In r13-3766 I changed the logic at the end of tourney to avoid redundant
comparisons, but the change also meant skipping any less-good matches
between the champ_compared_to_predecessor candidate and champ itself.

This should not be a correctness issue, since we believe that joust is a
partial order.  But it can lead to missed warnings, as in this testcase.

gcc/cp/ChangeLog:

	* call.cc (tourney): Only skip champ_compared_to_predecessor.

gcc/testsuite/ChangeLog:

	* g++.dg/warn/Wsign-promo1.C: New test.

An expresion node's type is streamed after the expression's operands,
because the type can come from some aspect of an operand (for instance
decltype and noexcept). There's a comment in the code explaining that.

But that doesn't work for constructors, which can directly reference
components of their type (eg FIELD_DECLS). If this is a
type-introducing CONSTRUCTOR, we need to ensure the type has been
streamed first. So move CONSTRUCTOR stream to after the type streaming.

The reason things like COMPONENT_REF work is that they stream their
first operand first, and that introduces the type that their second
operand looks up a field in.

	gcc/cp/
	PR c++/105322
	* module.cc (trees_out::core_vals): Stream CONSTRUCTOR operands
	after the type.
	(trees_in::core_vals): Likewise.
	gcc/testsuite/
	* g++.dg/modules/decltype-1_a.C: New.
	* g++.dg/modules/decltype-1_b.C: New.
	* g++.dg/modules/lambda-5_a.C: New.
	* g++.dg/modules/lambda-5_b.C: New.

gcc/c/

	PR c/109827
	PR other/44209
	* c-typeck.cc (build_conditional_expr): Use OPT_Wint_conversion
	for pointer/integer mismatch warnings.

gcc/testsuite/

	* gcc.dg/Wint-conversion-3.c: New.

gcc/c/

	PR c/109826
	PR other/44209
	* c-typeck.cc (build_conditional_expr): Use
	OPT_Wincompatible_pointer_types for pointer mismatches.
	Emit location information for the operand.

gcc/testsuite/

	* gcc.dg/Wincompatible-pointer-types-2.c: New.
	* gcc.dg/Wincompatible-pointer-types-3.c: New.
	* gcc.dg/Wincompatible-pointer-types-4.c: New.

SPARC target header references memmodel, which requires memmodel.h.

gcc/ChangeLog:

	* gimple-harden-control-flow.cc: Include memmodel.h.

Signed-off-by: David Edelsohn <dje.gcc@gmail.com>

In the PR, Joseph says that in C char8_t is not a distinct type.  So
we should behave as if it can alias anything, like ordinary char.
In C, unsigned_char_type_node == char8_type_node, so with this patch
we return 0 instead of -1.  And the following comment says:

  /* The C standard guarantees that any object may be accessed via an
     lvalue that has narrow character type (except char8_t).  */
  if (t == char_type_node
      || t == signed_char_type_node
      || t == unsigned_char_type_node)
    return 0;

Which appears to be wrong, so I'm adjusting that as well.

	PR c/111884

gcc/c-family/ChangeLog:

	* c-common.cc (c_common_get_alias_set): Return -1 for char8_t only
	in C++.

gcc/testsuite/ChangeLog:

	* c-c++-common/alias-1.c: New test.

ASM_GENERATE_INTERNAL_LABEL may use target-specific functions, so
tm_p.h must be included.  This fixes bootstrap breakage on AIX, at least.

gcc/ChangeLog

	* gimple-harden-control-flow.cc: Include tm_p.h.

Signed-off-by: David Edelsohn <dje.gcc@gmail.com>

This patch removes stray NON_DEPENDENT_EXPR checks following the removal
of this tree code from the C++ FE.  (Since this restores the build I
supppose it means the Rust FE never creates NON_DEPENDENT_EXPR trees in
the first place, so no further analysis is needed.)

	PR rust/111899

gcc/rust/ChangeLog:

	* backend/rust-constexpr.cc (potential_constant_expression_1):
	Remove NON_DEPENDENT_EXPR handling.
	* backend/rust-tree.cc (mark_exp_read): Likewise.
	(mark_use): Likewise.
	(lvalue_kind): Likewise.

This fixes

.../charconv: In function 'std::from_chars_result std::from_chars(const char*, const char*, _Float16&, chars_format)':
.../charconv:687:17: warning: converting to '_Float16' from 'float' with greater conversion rank
  687 |       __value = __val;
      |                 ^~~~~
.../charconv: In function 'std::from_chars_result std::from_chars(const char*, const char*, __gnu_cxx::__bfloat16_t&, chars_format)':
.../charconv:763:17: warning: converting to '__gnu_cxx::__bfloat16_t' {aka '__bf16'} from 'float' with greater conversion rank
  763 |       __value = __val;
      |                 ^~~~~

which was breaking a test:

FAIL: g++.dg/warn/Wstringop-overflow-6.C  -std=gnu++26 (test for excess errors)

	PR testsuite/111883

libstdc++-v3/ChangeLog:

	* include/std/charconv (from_chars): Add explicit casts.

This patch stops lowering of bitfields by ifcvt when they have non-constant
offsets as we are not likely to be able to do anything useful with those during
vectorization.  That also fixes the issue reported in PR 111882, which was
being caused by an offset with a side-effect being lowered, but constants have
no side-effects so we will no longer run into that problem.

gcc/ChangeLog:

	PR tree-optimization/111882
	* tree-if-conv.cc (get_bitfield_rep): Return NULL_TREE for bitfields
	with non-constant offsets.

gcc/testsuite/ChangeLog:

	* gcc.dg/vect/pr111882.c: New test.

After the previous patch, we now only have two tsubst entry points for
expression trees: tsubst_copy_and_build and tsubst_expr.  The former
despite its unwieldy name is the main entry point, and the latter is
just a superset of the former that also handles statement trees.  We
could merge them so that we just have tsubst_expr, but it seems natural
to distinguish statement trees from expression trees and to maintain a
separate entry point for them.

To that end, this this patch renames tsubst_copy_and_build to
tsubst_expr, and renames the current tsubst_expr to tsubst_stmt, which
continues to be a superset of the former (which is convenient since
sometimes expression trees appear in statement contexts, e.g. a branch
of an IF_STMT could be NOP_EXPR).  (Making tsubst_stmt disjoint from
tsubst_expr is left as future work if deemed desirable.)

This patch in turn renames suitable existing uses of tsubst_expr (that
expect to take statement trees) to use tsubst_stmt.  Thus untouched
tsubst_expr calls are implicitly strengthened to expect only expression
trees after this patch.  For the tsubst_omp_* routines I opted to rename
all existing uses to ensure no unintended functional change.  This patch
also moves the handling of CO_YIELD_EXPR and CO_AWAIT_EXPR from tsubst_stmt
to tsubst_expr since they're indeed expression trees.

gcc/cp/ChangeLog:

	* cp-lang.cc (objcp_tsubst_copy_and_build): Rename to ...
	(objcp_tsubst_expr): ... this.
	* cp-objcp-common.h (objcp_tsubst_copy_and_build): Rename to ...
	(objcp_tsubst_expr): ... this.
	* cp-tree.h (tsubst_copy_and_build): Remove declaration.
	* init.cc (maybe_instantiate_nsdmi_init): Use tsubst_expr
	instead of tsubst_copy_and_build.
	* pt.cc (expand_integer_pack): Likewise.
	(instantiate_non_dependent_expr_internal): Likewise.
	(instantiate_class_template): Use tsubst_stmt instead of
	tsubst_expr for STATIC_ASSERT.
	(tsubst_function_decl): Adjust tsubst_copy_and_build uses.
	(tsubst_arg_types): Likewise.
	(tsubst_exception_specification): Likewise.
	(tsubst_tree_list): Likewise.
	(tsubst): Likewise.
	(tsubst_name): Likewise.
	(tsubst_omp_clause_decl): Use tsubst_stmt instead of tsubst_expr.
	(tsubst_omp_clauses): Likewise.
	(tsubst_copy_asm_operands): Adjust tsubst_copy_and_build use.
	(tsubst_omp_for_iterator): Use tsubst_stmt instead of tsubst_expr.
	(tsubst_expr): Rename to ...
	(tsubst_stmt): ... this.
	<case CO_YIELD_EXPR, CO_AWAIT_EXPR>: Move to tsubst_expr.
	(tsubst_omp_udr): Use tsubst_stmt instead of tsubst_expr.
	(tsubst_non_call_postfix_expression): Adjust tsubst_copy_and_build
	use.
	(tsubst_lambda_expr): Likewise.  Use tsubst_stmt instead of
	tsubst_expr for the body of a lambda.
	(tsubst_copy_and_build_call_args): Rename to ...
	(tsubst_call_args): ... this.  Adjust tsubst_copy_and_build use.
	(tsubst_copy_and_build): Rename to tsubst_expr.  Adjust
	tsubst_copy_and_build and tsubst_copy_and_build_call_args use.
	<case TRANSACTION_EXPR>: Use tsubst_stmt instead of tsubst_expr.
	(maybe_instantiate_noexcept): Adjust tsubst_copy_and_build use.
	(instantiate_body): Use tsubst_stmt instead of tsubst_expr for
	substituting the function body.
	(tsubst_initializer_list): Adjust tsubst_copy_and_build use.

gcc/objcp/ChangeLog:

	* objcp-lang.cc (objcp_tsubst_copy_and_build): Rename to ...
	(objcp_tsubst_expr): ... this.  Adjust tsubst_copy_and_build
	uses.

Reviewed-by: Jason Merrill <jason@redhat.com>

The relationship between tsubst_copy_and_build and tsubst_copy (two of
the main template argument substitution routines for expression trees)
is rather hazy.  The former is mostly a superset of the latter, with
some differences.

The main apparent difference is their handling of various tree codes,
but much of the tree code handling in tsubst_copy appears to be dead
code.  This is because tsubst_copy mostly gets (directly) called on
id-expressions rather than on arbitrary expressions.  The interesting
tree codes are PARM_DECL, VAR_DECL, BIT_NOT_EXPR, SCOPE_REF,
TEMPLATE_ID_EXPR and IDENTIFIER_NODE:

 * for PARM_DECL and VAR_DECL, tsubst_copy_and_build calls tsubst_copy
   followed by doing some extra handling of its own
 * for BIT_NOT_EXPR tsubst_copy implicitly handles unresolved destructor
   calls (i.e. the first operand is an identifier or a type)
 * for SCOPE_REF, TEMPLATE_ID_EXPR and IDENTIFIER_NODE tsubst_copy
   refrains from doing name lookup of the terminal name

Other more minor differences are that tsubst_copy exits early when
'args' is null, and it calls maybe_dependent_member_ref, and finally
it dispatches to tsubst for type trees.[1]

Thus tsubst_copy is similar enough to tsubst_copy_and_build that it
makes sense to merge the two functions, with the main difference we
want to preserve is tsubst_copy's lack of name lookup for id-expressions.
This patch achieves this via a new tsubst flag tf_no_name_lookup which
controls name lookup and resolution of a (top-level) id-expression.

[1]: Exiting early for null 'args' doesn't seem right since it means we
return templated trees even when !processing_template_decl.  And
dispatching to tsubst for type trees muddles the distinction between
type and expressions which makes things less clear at the call site.
So these properties of tsubst_copy don't seem worth preserving.

N.B. the diff for this patch looks much cleaner when generated using
the "patience diff" algorithm via Git's --patience flag.

gcc/cp/ChangeLog:

	* cp-tree.h (enum tsubst_flags): Add tf_no_name_lookup.
	* pt.cc (tsubst_pack_expansion): Use tsubst for substituting
	BASES_TYPE.
	(tsubst_decl) <case USING_DECL>: Use tsubst_name instead of
	tsubst_copy.
	(tsubst) <case TEMPLATE_TYPE_PARM>: Use tsubst_copy_and_build
	instead of tsubst_copy for substituting
	CLASS_PLACEHOLDER_TEMPLATE.
	<case TYPENAME_TYPE>: Use tsubst_name instead of tsubst_copy for
	substituting TYPENAME_TYPE_FULLNAME.
	(tsubst_name): Define.
	(tsubst_qualified_id): Use tsubst_name instead of tsubst_copy
	for substituting the component name of a SCOPE_REF.
	(tsubst_copy): Remove.
	(tsubst_copy_and_build): Clear tf_no_name_lookup at the start,
	and remember if it was set.  Call maybe_dependent_member_ref if
	tf_no_name_lookup was not set.
	<case IDENTIFIER_NODE>: Don't do name lookup if tf_no_name_lookup
	was set.
	<case TEMPLATE_ID_EXPR>: If tf_no_name_lookup was set, use
	tsubst_name instead of tsubst_copy_and_build to substitute the
	template and don't finish the template-id.
	<case BIT_NOT_EXPR>: Handle identifier and type operand (if
	tf_no_name_lookup was set).
	<case SCOPE_REF>: Avoid trying to resolve a SCOPE_REF if
	tf_no_name_lookup was set by calling build_qualified_name directly
	instead of tsubst_qualified_id.
	<case SIZEOF_EXPR>: Handling of sizeof...  copied from tsubst_copy.
	<case CALL_EXPR>: Use tsubst_name instead of tsubst_copy to
	substitute a TEMPLATE_ID_EXPR callee naming an unresolved template.
	<case COMPONENT_REF>: Likewise to substitute the member.
	<case FUNCTION_DECL>: Copied from tsubst_copy and merged with ...
	<case VAR_DECL, PARM_DECL>: ... these.  Initial handling copied
	from tsubst_copy.  Optimize local variable substitution by
	trying retrieve_local_specialization before checking
	uses_template_parms.
	<case CONST_DECL>: Copied from tsubst_copy.
	<case FIELD_DECL>: Likewise.
	<case NAMESPACE_DECL>: Likewise.
	<case OVERLOAD>: Likewise.
	<case TEMPLATE_DECL>: Likewise.
	<case TEMPLATE_PARM_INDEX>: Likewise.
	<case TYPE_DECL>: Likewise.
	<case CLEANUP_POINT_EXPR>: Likewise.
	<case OFFSET_REF>: Likewise.
	<case EXPR_PACK_EXPANSION>: Likewise.
	<case NONTYPE_ARGUMENT_PACK>: Likewise.
	<case *_CST>: Likewise.
	<case *_*_FOLD_EXPR>: Likewise.
	<case DEBUG_BEGIN_STMT>: Likewise.
	<case CO_AWAIT_EXPR>: Likewise.
	<case TRAIT_EXPR>: Use tsubst and tsubst_copy_and_build instead
	of tsubst_copy.
	<default>: Copied from tsubst_copy.
	(tsubst_initializer_list): Use tsubst and tsubst_copy_and_build
	instead of tsubst_copy.

Reviewed-by: Jason Merrill <jason@redhat.com>

In cp_parser_postfix_expression, and in the CALL_EXPR case of
tsubst_copy_and_build, we essentially repeat the type-dependent and
COMPONENT_REF callee cases of finish_call_expr.  This patch deduplicates
this logic by making both spots consistently go through finish_call_expr.

This allows us to easily fix PR106086 -- which is about us neglecting to
capture 'this' when we resolve a use of a non-static member function of
the current instantiation only at lambda regeneration time -- by moving
the call to maybe_generic_this_capture from the parser to finish_call_expr
so that we consider capturing 'this' at regeneration time as well.

	PR c++/106086

gcc/cp/ChangeLog:

	* parser.cc (cp_parser_postfix_expression): Consolidate three
	calls to finish_call_expr, one to build_new_method_call and
	one to build_min_nt_call_vec into one call to finish_call_expr.
	Don't call maybe_generic_this_capture here.
	* pt.cc (tsubst_copy_and_build) <case CALL_EXPR>: Remove
	COMPONENT_REF callee handling.
	(type_dependent_expression_p): Use t_d_object_e_p instead of
	t_d_e_p for COMPONENT_REF and OFFSET_REF.
	* semantics.cc (finish_call_expr): In the type-dependent case,
	call maybe_generic_this_capture here instead.

gcc/testsuite/ChangeLog:

	* g++.dg/template/crash127.C: Expect additional error due to
	being able to check the member access expression ahead of time.
	Strengthen the test by not instantiating the class template.
	* g++.dg/cpp1y/lambda-generic-this5.C: New test.

This follow-up patch removes build_non_dependent_expr (and
make_args_non_dependent) and calls thereof, no functional change.

gcc/cp/ChangeLog:

	* call.cc (build_new_method_call): Remove calls to
	build_non_dependent_expr and/or make_args_non_dependent.
	* coroutines.cc (finish_co_return_stmt): Likewise.
	* cp-tree.h (build_non_dependent_expr): Remove.
	(make_args_non_dependent): Remove.
	* decl2.cc (grok_array_decl): Remove calls to
	build_non_dependent_expr and/or make_args_non_dependent.
	(build_offset_ref_call_from_tree): Likewise.
	* init.cc (build_new): Likewise.
	* pt.cc (make_args_non_dependent): Remove.
	(test_build_non_dependent_expr): Remove.
	(cp_pt_cc_tests): Adjust.
	* semantics.cc (finish_expr_stmt): Remove calls to
	build_non_dependent_expr and/or make_args_non_dependent.
	(finish_for_expr): Likewise.
	(finish_call_expr): Likewise.
	(finish_omp_atomic): Likewise.
	* typeck.cc (finish_class_member_access_expr): Likewise.
	(build_x_indirect_ref): Likewise.
	(build_x_binary_op): Likewise.
	(build_x_array_ref): Likewise.
	(build_x_vec_perm_expr): Likewise.
	(build_x_shufflevector): Likewise.
	(build_x_unary_op): Likewise.
	(cp_build_addressof): Likewise.
	(build_x_conditional_expr): Likewise.
	(build_x_compound_expr): Likewise.
	(build_static_cast): Likewise.
	(build_x_modify_expr): Likewise.
	(check_return_expr): Likewise.
	* typeck2.cc (build_x_arrow): Likewise.

Reviewed-by: Jason Merrill <jason@redhat.com>

This tree code dates all the way back to r69130[1] which implemented
typing of non-dependent expressions.  Its motivation was never clear (to
me at least) since its documentation in e.g. cp-tree.def doesn't seem
accurate anymore.  build_non_dependent_expr has since gained a bunch of
edge cases about whether or how to wrap certain templated trees, making
it hard to reason about in general.

So this patch removes this tree code, and temporarily turns
build_non_dependent_expr into the identity function.  The subsequent
patch will remove build_non_dependent_expr and adjust its callers
appropriately.

We now need to more thoroughly handle templated (sub)trees in a couple
of places which previously didn't need to since they didn't look through
NON_DEPENDENT_EXPR.

[1]: https://gcc.gnu.org/pipermail/gcc-patches/2003-July/109355.html



gcc/c-family/ChangeLog:

	* c-warn.cc (check_address_or_pointer_of_packed_member): Handle
	type-dependent callee of CALL_EXPR.

gcc/cp/ChangeLog:

	* class.cc (instantiate_type): Remove NON_DEPENDENT_EXPR
	handling.
	* constexpr.cc (cxx_eval_constant_expression): Likewise.
	(potential_constant_expression_1): Likewise.
	* coroutines.cc (coro_validate_builtin_call): Don't
	expect ALIGNOF_EXPR to be wrapped in NON_DEPENDENT_EXPR.
	* cp-objcp-common.cc (cp_common_init_ts): Remove
	NON_DEPENDENT_EXPR handling.
	* cp-tree.def (NON_DEPENDENT_EXPR): Remove.
	* cp-tree.h (build_non_dependent_expr): Temporarily redefine as
	the identity function.
	* cvt.cc (maybe_warn_nodiscard): Handle type-dependent and
	variable callee of CALL_EXPR.
	* cxx-pretty-print.cc (cxx_pretty_printer::expression): Remove
	NON_DEPENDENT_EXPR handling.
	* error.cc (dump_decl): Likewise.
	(dump_expr): Likewise.
	* expr.cc (mark_use): Likewise.
	(mark_exp_read): Likewise.
	* pt.cc (build_non_dependent_expr): Remove.
	* tree.cc (lvalue_kind): Remove NON_DEPENDENT_EXPR handling.
	(cp_stabilize_reference): Likewise.
	* typeck.cc (warn_for_null_address): Likewise.
	(cp_build_binary_op): Handle type-dependent SIZEOF_EXPR operands.
	(cp_build_unary_op) <case TRUTH_NOT_EXPR>: Don't fold inside a
	template.

gcc/testsuite/ChangeLog:

	* g++.dg/concepts/var-concept3.C: Adjust expected diagnostic
	for attempting to call a variable concept.

Reviewed-by: Jason Merrill <jason@redhat.com>

During the refactoring I had passed loop_vinfo on to vect_set_loop_condition
during prolog peeling.  This parameter is unused in most cases except for in
vect_set_loop_condition_partial_vectors where it's behaviour depends on whether
loop_vinfo is NULL or not.  Apparently this code expect it to be NULL and it
reads the structures from a different location.

This fixes the failing testcase which was not using the lens values determined
earlier in vectorizable_store because it was looking it up in the given
loop_vinfo instead.

gcc/ChangeLog:

	PR tree-optimization/111866
	* tree-vect-loop-manip.cc (vect_do_peeling): Pass null as vinfo to
	vect_set_loop_condition during prolog peeling.

	PR tree-optimization/111383
	PR tree-optimization/110243
gcc/testsuite/
	* gcc.dg/torture/pr111383.c: New testcase.

The following fixes a missed check in the simple_iv attempt
to simplify (signed T)((unsigned T) base + step) where it
allows a truncating inner conversion leading to wrong code.

	PR tree-optimization/111445
	* tree-scalar-evolution.cc (simple_iv_with_niters):
	Add missing check for a sign-conversion.

	* gcc.dg/torture/pr111445.c: New testcase.

The following addresses IVOPTs rewriting expressions in its
strip_offset without caring for definedness of overflow.  Rather
than the earlier attempt of just using the proper
split_constant_offset from data-ref analysis the following adjusts
IVOPTs helper trying to minimize changes from this fix, possibly
easing backports.

	PR tree-optimization/110243
	PR tree-optimization/111336
	* tree-ssa-loop-ivopts.cc (strip_offset_1): Rewrite
	operations with undefined behavior on overflow to
	unsigned arithmetic.

	* gcc.dg/torture/pr110243.c: New testcase.
	* gcc.dg/torture/pr111336.c: Likewise.

The following fixes the assert in vectorizable_simd_clone_call to
assert we have a vector type during transform.  Whether we have
one during analysis depends on whether another SLP user decided
on the type of a constant/external already.  When we end up with
a mismatch in desire the updating will fail and make vectorization
fail.

	PR tree-optimization/111891
	* tree-vect-stmts.cc (vectorizable_simd_clone_call): Fix
	assert.

	* gfortran.dg/pr111891.f90: New testcase.

Accept the architecture configure option and resolve build failures.  This is
enough to build binaries, but I've not got a device to test it on, so there
are probably runtime issues to fix.  The cache control instructions might be
unsafe (or too conservative), and the kernel metadata might be off.  Vector
reductions will need to be reworked for RDNA2.  In principle, it would be
better to use wavefrontsize32 for this architecture, but that would mean
switching everything to allow SImode masks, so wavefrontsize64 it is.

The multilib is not included in the default configuration so either configure
--with-arch=gfx1030 or include it in --with-multilib-list=gfx1030,....

The majority of this patch has no effect on other devices, but changing from
using scalar writes for the exit value to vector writes means we don't need
the scalar cache write-back instruction anywhere (which doesn't exist in RDNA2).

gcc/ChangeLog:

	* config.gcc: Allow --with-arch=gfx1030.
	* config/gcn/gcn-hsa.h (NO_XNACK): gfx1030 does not support xnack.
	(ASM_SPEC): gfx1030 needs -mattr=+wavefrontsize64 set.
	* config/gcn/gcn-opts.h (enum processor_type): Add PROCESSOR_GFX1030.
	(TARGET_GFX1030): New.
	(TARGET_RDNA2): New.
	* config/gcn/gcn-valu.md (@dpp_move<mode>): Disable for RDNA2.
	(addc<mode>3<exec_vcc>): Add RDNA2 syntax variant.
	(subc<mode>3<exec_vcc>): Likewise.
	(<convop><mode><vndi>2_exec): Add RDNA2 alternatives.
	(vec_cmp<mode>di): Likewise.
	(vec_cmp<u><mode>di): Likewise.
	(vec_cmp<mode>di_exec): Likewise.
	(vec_cmp<u><mode>di_exec): Likewise.
	(vec_cmp<mode>di_dup): Likewise.
	(vec_cmp<mode>di_dup_exec): Likewise.
	(reduc_<reduc_op>_scal_<mode>): Disable for RDNA2.
	(*<reduc_op>_dpp_shr_<mode>): Likewise.
	(*plus_carry_dpp_shr_<mode>): Likewise.
	(*plus_carry_in_dpp_shr_<mode>): Likewise.
	* config/gcn/gcn.cc (gcn_option_override): Recognise gfx1030.
	(gcn_global_address_p): RDNA2 only allows smaller offsets.
	(gcn_addr_space_legitimate_address_p): Likewise.
	(gcn_omp_device_kind_arch_isa): Recognise gfx1030.
	(gcn_expand_epilogue): Use VGPRs instead of SGPRs.
	(output_file_start): Configure gfx1030.
	* config/gcn/gcn.h (TARGET_CPU_CPP_BUILTINS): Add __RDNA2__;
	(ASSEMBLER_DIALECT): New.
	* config/gcn/gcn.md (rdna): New define_attr.
	(enabled): Use "rdna" attribute.
	(gcn_return): Remove s_dcache_wb.
	(addcsi3_scalar): Add RDNA2 syntax variant.
	(addcsi3_scalar_zero): Likewise.
	(addptrdi3): Likewise.
	(mulsi3): v_mul_lo_i32 should be v_mul_lo_u32 on all ISA.
	(*memory_barrier): Add RDNA2 syntax variant.
	(atomic_load<mode>): Add RDNA2 cache control variants, and disable
	scalar atomics for RDNA2.
	(atomic_store<mode>): Likewise.
	(atomic_exchange<mode>): Likewise.
	* config/gcn/gcn.opt (gpu_type): Add gfx1030.
	* config/gcn/mkoffload.cc (EF_AMDGPU_MACH_AMDGCN_GFX1030): New.
	(main): Recognise -march=gfx1030.
	* config/gcn/t-omp-device: Add gfx1030 isa.

libgcc/ChangeLog:

	* config/gcn/amdgcn_veclib.h (CDNA3_PLUS): Set false for __RDNA2__.

libgomp/ChangeLog:

	* plugin/plugin-gcn.c (EF_AMDGPU_MACH_AMDGCN_GFX1030): New.
	(isa_hsa_name): Recognise gfx1030.
	(isa_code): Likewise.
	* team.c (defined): Remove s_endpgm.

The following restricts moving variable shifts to when they are
always executed in the loop as we currently do not have an efficient
way to rewrite them to something that is unconditionally
well-defined and value range analysis will otherwise compute
invalid ranges for the shift operand.

	PR tree-optimization/111000
	* stor-layout.h (element_precision): Move ..
	* tree.h (element_precision): .. here.
	* tree-ssa-loop-im.cc (movement_possibility_1): Restrict
	motion of shifts and rotates.

	* gcc.dg/torture/pr111000.c: New testcase.