My previous change to the Thumb-2 movsi patterns caused a codesize regression
with -Os in large functions.  Fix this by using the literal pool offset of the
16-bit literal load so that the literal pool is dumped earlier, reducing the
number of 32-bit literal loads.

Bootstrap & regress OK on arm-none-linux-gnueabihf --with-cpu=cortex-a57

    gcc/
	* config/arm/thumb2.md (thumb2_movsi_insn): Adjust literal offset.
	* config/arm/vfp.md (thumb2_movsi_vfp): Likewise.

From-SVN: r273911

2019-07-30  Martin Liska  <mliska@suse.cz>

	PR ipa/89330
	* cgraph.c (cgraph_edge::make_direct): Use
	edge->indirect_unknown_callee as edge->resolve_speculation can
	deallocate edge which is this pointer.

From-SVN: r273910

2019-07-30  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/91257
	* bitmap.c (bitmap_ior_and_compl_into): Open-code.

From-SVN: r273909

2019-07-30  Martin Liska  <mliska@suse.cz>

	* doc/invoke.texi: Document new behavior.
	* lto-wrapper.c (cpuset_popcount): New function
	is a copy of libgomp/config/linux/proc.c.
	(init_num_threads): Likewise.
	(run_gcc): Automatically detect core count for -flto.
	(jobserver_active_p): New function.

From-SVN: r273908

2019-07-30  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/91257
	* bitmap.h (bitmap_ior_into_and_free): Declare.
	* bitmap.c (bitmap_list_unlink_element): Add defaulted param
	whether to add the unliked element to the freelist.
	(bitmap_list_insert_element_after): Add defaulted param for
	an already allocated element.
	(bitmap_ior_into_and_free): New function.
	* tree-ssa-structalias.c (condense_visit): Reduce the
	ponts-to and edge bitmaps of the SCC members in a
	logarithmic fashion rather than all to one.

From-SVN: r273907

2019-07-30  Martin Liska  <mliska@suse.cz>

	PR tree-optimization/91270
	* tree-ssa-dce.c (propagate_necessity): Mark 2nd argument
	of delete operator as needed.
2019-07-30  Martin Liska  <mliska@suse.cz>

	PR tree-optimization/91270
	* g++.dg/torture/pr91270.C: New test.

From-SVN: r273906

This patch extends the FMA handling in tree-ssa-math-opts.c so
that it can cope with conditional multiplications as well as
unconditional multiplications.  The addition or subtraction must then
have the same condition as the multiplication (at least for now).

E.g. we can currently fold:

  (IFN_COND_ADD cond (mul x y) z fallback)
    -> (IFN_COND_FMA cond x y z fallback)

This patch also allows:

  (IFN_COND_ADD cond (IFN_COND_MUL cond x y <whatever>) z fallback)
    -> (IFN_COND_FMA cond x y z fallback)

2019-07-30  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* tree-ssa-math-opts.c (convert_mult_to_fma): Add a mul_cond
	parameter.  When nonnull, make sure that the addition or subtraction
	has the same condition.
	(math_opts_dom_walker::after_dom_children): Try convert_mult_to_fma
	for CFN_COND_MUL too.

gcc/testsuite/
	* gcc.dg/vect/vect-cond-arith-7.c: New test.

From-SVN: r273905

2019-07-30  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/91291
	* tree-ssa-sccvn.c (rpo_elim::eliminate_push_avail): Ignore
	constant values.

From-SVN: r273903

	PR middle-end/91282
	* gcc.dg/type-convert-var.c: Add -fexcess-precision=fast to
	dg-additional-options.

From-SVN: r273899

	PR middle-end/91216
	* omp-low.c (global_nonaddressable_vars): New variable.
	(use_pointer_for_field): For global decls, if they are non-addressable,
	remember it in the global_nonaddressable_vars bitmap, if they are
	addressable and in the global_nonaddressable_vars bitmap, ignore their
	TREE_ADDRESSABLE bit.
	(omp_copy_decl_2): Clear TREE_ADDRESSABLE also on private copies of
	vars in global_nonaddressable_vars bitmap.
	(execute_lower_omp): Free global_nonaddressable_vars bitmap.

	* gcc.dg/gomp/pr91216.c: New test.

From-SVN: r273898

	PR target/91150
	* config/i386/i386-expand.c (expand_vec_perm_blend): Change mask type
	from unsigned to unsigned HOST_WIDE_INT.  For E_V64QImode cast
	comparison to unsigned HOST_WIDE_INT before shifting it left.

	* gcc.target/i386/avx512bw-pr91150.c: New test.

From-SVN: r273897

From-SVN: r273896

	* config/i386/i386.md (movstrict<mode>): Use register_operand
	predicate for operand 0.  Add expander condition.  Assert that
	operand 0 is a SUBREG RTX.
	(*movstrict<mode>_1): Use register_operand predicate for operand 0.
	Update operand constraints and insn condition.
	(zero_extend<mode>si2_and): Do not call gen_movstrict<mode>.
	(zero_extendqihi2_and): Do not call gen_movstrictqi.
	(*setcc_qi_slp): Use register_operand predicate for operand 0.
	Update operand 0 constraints.
	(setcc_qi_slp splitters): Use register_operand predicate for operand 0.

From-SVN: r273891

gcc/ChangeLog:

2019-07-29  Jozef Lawrynowicz  <jozef.l@mittosystems.com>

	* config/msp430/msp430.h (DRIVER_SELF_SPECS): Define and emit errors
	when -m{code,data}-region are used without -mlarge.
	* config/msp430/msp430.c (msp430_option_override): Error when a
	non-default code or data region is used without -mlarge.
	(msp430_section_attr): Emit a warning and do not add upper/lower/either
	attributes when they are used without -mlarge.

gcc/testsuite/ChangeLog:

2019-07-29  Jozef Lawrynowicz  <jozef.l@mittosystems.com>

	* gcc.target/msp430/pr78818-data-region.c: Add -mlarge to dg-options.
	* gcc.target/msp430/region-misuse-code.c: New test.
	* gcc.target/msp430/region-misuse-data.c: Likewise.
	* gcc.target/msp430/region-misuse-code-data.c: Likewise.
	* gcc.target/msp430/region-attribute-misuse.c: Likewise.

From-SVN: r273884

2019-07-29  Jozef Lawrynowicz  <jozef.l@mittosystems.com>

	PR target/70320
	* config/msp430/msp430.h: Define ADDITIONAL_REGISTER_NAMES.

2019-07-29  Jozef Lawrynowicz  <jozef.l@mittosystems.com>

	PR target/70320
	* gcc.target/msp430/asm-register-names-lower-case.c: New test.
	* gcc.target/msp430/asm-register-names-upper-case.c: Likewise.

From-SVN: r273883

From-SVN: r273882

inchash::hash::add_wide_int operated directly on the raw encoding
of the wide_int, including any redundant upper bits.  The problem
with that is that the upper bits are only defined for some wide-int
storage types (including wide_int itself).  wi::to_wide(tree) instead
returns a value that is extended according to the signedness of the
type (so that wi::to_widest can use the same encoding) while rtxes
have the awkward special case of BI, which can be zero-extended
rather than sign-extended.

In the PR, we computed a hash for a "normal" sign-extended wide_int
while the existing entries hashed wi::to_wide(tree).  This gives
different results for unsigned types that have the top bit set.

The patch fixes that by hashing the canonical sign-extended form even
if the raw encoding happens to be different.

2019-07-29  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* wide-int.h (generic_wide_int::sext_elt): New function.
	* inchash.h (hash::add_wide_int): Use it instead of elt.

From-SVN: r273881

2019-07-29  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/90813
	* dump-parse-tree.c (show_global_symbol): New function.
	(gfc_dump_global_symbols): New function.
	* gfortran.h (gfc_traverse_gsymbol): Add prototype.
	(gfc_dump_global_symbols): Likewise.
	* invoke.texi: Document -fdump-fortran-global.
	* lang.opt: Add -fdump-fortran-global.
	* parse.c (gfc_parse_file): Handle flag_dump_fortran_global.
	* symbol.c (gfc_traverse_gsymbol): New function.
	* trans-decl.c (sym_identifier): New function.
	(mangled_identifier): New function, doing most of the work
	of gfc_sym_mangled_identifier.
	(gfc_sym_mangled_identifier): Use mangled_identifier.  Add mangled
	identifier to global symbol table.
	(get_proc_pointer_decl): Use backend decl from global identifier
	if present.

From-SVN: r273880

The builtins from <arm_acle.h> use fairly general expander names such as
"crc", "mcr" etc.
These run the risk of being reserved by the midend in the future.
Let's namespace them to arm_* as is convention.

	* config/arm/arm-builtins.c (acle_builtin_data): Expand VAR1 to
	CODE_FOR_arm_##.
	* config/arm/arm.md (<crc_variant>): Rename to...
	(arm_<crc_variant>): ... This.
	(<cdp>): Rename to...
	(arm_<cdp>): ... This.
	(<ldc>): Rename to...
	(arm_<ldc>): ... This.
	(<stc>): Rename to...
	(arm_<stc>): ... This.
	(<mcr>): Rename to...
	(arm_<mcr>): ... This.
	(<mrc>): Rename to...
	(arm_<mrc>): ... This.
	(<mcrr>): Rename to...
	(arm_<mcrr>): ... This.
	(<mrrc>): Rename to...
	(arm_<mrrc>): ... This.

From-SVN: r273879

The recursive_init_error class is defined in a header, with an inline
constructor, but the definition of the vtable and destructor are not
exported from the shared library. With -fkeep-inline-functions the
constructor gets emitted in user code, and requires the (non-exported)
vtable. This fails to link.

As far as I can tell, the recursive_init_error class definition was
moved into <cxxabi.h> so it could be documented with Doxygen, not for
any technical reason. But now it's there (and documented), somebody
could be relying on it, by catching that type and possibly performing
derived-to-base conversions to the std::exception base class. So the
conservative fix is to leave the class definition in the header but make
the constructor non-inline. This still allows the type to be caught and
still defines its base class. User code can no longer construct objects
of that type, but that's not something we need to support.

	PR libstdc++/51333
	* libsupc++/cxxabi.h (__gnu_cxx::recursive_init_error): Do not define
	constructor inline.
	* libsupc++/guard_error.cc (__gnu_cxx::recursive_init_error): Define
	constructor.
	* testsuite/18_support/51333.cc: New test.

From-SVN: r273878

2019-07-29  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/91257
	* tree-ssa-sccvn.h (struct vn_avail): New.
	(struct vn_ssa_aux): Add avail member.
	* tree-ssa-sccvn.c (class rpo_elim): Remove m_rpo_avail
	member, add m_avail_freelist one.
	(rpo_elim::~rpo_elim): Remove.
	(rpo_elim::eliminate_avail): Adjust to new avail tracking
	data structure.
	(rpo_elim::eliminate_push_avail): Likewise.
	(do_unwind): Likewise.
	(do_rpo_vn): Likewise.

From-SVN: r273877

2019-07-29  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/91257
	* tree-vrp.c (operand_less_p): Avoid dispatching to fold for
	most cases, instead call compare_values which handles the
	symbolic ranges we handle specially.
	(compare_values_warnv): Do not call operand_less_p but open-code
	the effective fold calls.  Avoid converting so much.

From-SVN: r273876

2019-07-29  Martin Liska  <mliska@suse.cz>

	* tree-ssa-dce.c (eliminate_unnecessary_stmts): Do not
	remove LHS of operator new call.  It's handled latter.
2019-07-29  Martin Liska  <mliska@suse.cz>

	* g++.dg/cpp1y/new1.C (test_unused): Add new case that causes
	ICE.

From-SVN: r273875

2019-07-29  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/91267
	* vr-values.c (vr_values::update_value_range): Add early return
	for effectively VARYING lattice entry.

	* gcc.dg/torture/pr91267.c: New testcase.

From-SVN: r273874

DCE tries to delete dead stores to local data and also tries to insert
debug binds for simple cases:

  /* If this is a store into a variable that is being optimized away,
     add a debug bind stmt if possible.  */
  if (MAY_HAVE_DEBUG_BIND_STMTS
      && gimple_assign_single_p (stmt)
      && is_gimple_val (gimple_assign_rhs1 (stmt)))
    {
      tree lhs = gimple_assign_lhs (stmt);
      if ((VAR_P (lhs) || TREE_CODE (lhs) == PARM_DECL)
	  && !DECL_IGNORED_P (lhs)
	  && is_gimple_reg_type (TREE_TYPE (lhs))
	  && !is_global_var (lhs)
	  && !DECL_HAS_VALUE_EXPR_P (lhs))
	{
	  tree rhs = gimple_assign_rhs1 (stmt);
	  gdebug *note
	    = gimple_build_debug_bind (lhs, unshare_expr (rhs), stmt);
	  gsi_insert_after (i, note, GSI_SAME_STMT);
	}
    }

But this doesn't help for things like "print *ptr" when ptr points
to the local variable (tests Og-dce-1.c and Og-dce-2.c).  It can
also introduce wrong debug info for earlier references (second test
in Og-dce-3.c) or make earlier references unavailable (first test
in Og-dce-3.c).

So for -Og I think it'd be better not to delete any stmts with
vdefs for now.  This also means that we can avoid the potentially
expensive vop walks (which already have a cut-off, but still).

The patch also fixes the Og failures in gcc.dg/guality/pr54970.c
(PR 86638).

2019-07-29  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	PR debug/86638
	* tree-ssa-dce.c (keep_all_vdefs_p): New function.
	(mark_stmt_if_obviously_necessary): Mark all stmts with vdefs as
	necessary if keep_all_vdefs_p is true.
	(mark_aliased_reaching_defs_necessary): Add a gcc_checking_assert
	that keep_all_vdefs_p is false.
	(mark_all_reaching_defs_necessary): Likewise.
	(propagate_necessity): Skip the vuse scan if keep_all_vdefs_p is true.

gcc/testsuite/
	* c-c++-common/guality/Og-dce-1.c: New test.
	* c-c++-common/guality/Og-dce-2.c: Likewise.
	* c-c++-common/guality/Og-dce-3.c: Likewise.

From-SVN: r273872

This patch stops gimple and rtl DSE from running by default at -Og.
The idea is both to improve compile time and to stop us from deleting
stores that we can't track in debug info.

We could rein this back in future for stores to local variables
with is_gimple_reg_type, but at the moment we don't have any
infrastructure for switching between binds to specific values
and binds to evolving memory locations.  Even then, location
tracking only works for direct references to the variables, and doesn't
for example help with printing dereferenced pointers (see the next patch
in the series for an example).

I'm also not sure that DSE is important enough for -Og to justify the
compile time cost --  especially in the case of RTL DSE, which is pretty
expensive.

2019-07-29  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* common.opt (Og): Change the initial value of flag_dse to 0.
	* opts.c (default_options_table): Move OPT_ftree_dse from
	OPT_LEVELS_1_PLUS to OPT_LEVELS_1_PLUS_NOT_DEBUG.  Also add
	OPT_fdse to OPT_LEVELS_1_PLUS_NOT_DEBUG.  Put the OPT_ftree_pta
	entry before the OPT_ftree_sra entry.
	* doc/invoke.texi (Og): Add -fdse and -ftree-dse to the list
	of flags disabled by Og.

gcc/testsuite/
	* c-c++-common/guality/Og-global-dse-1.c: New test.

From-SVN: r273871

This patch prevents -Og from deleting stores to write-only variables,
so that the values are still available when debugging.  This seems
more convenient than forcing users to use __attribute__((used))
(probably conditionally, if it's not something they want in release
builds).

2019-07-29  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* tree-cfg.c (execute_fixup_cfg): Don't delete stores to write-only
	variables for -Og.

gcc/testsuite/
	* c-c++-common/guality/Og-static-wo-1.c: New test.
	* g++.dg/guality/guality.exp: Separate the c-c++-common tests into
	"Og" and "general" tests.  Run the latter at -O0 and -Og only.
	* gcc.dg/guality/guality.exp: Likewise.

From-SVN: r273870

There isn't a 1:1 mapping from SVE intrinsics to SVE instructions,
but the intrinsics are still close enough to the instructions for
there to be a specific preferred sequence (or sometimes choice of
preferred sequences) for a given combination of operands.  Sometimes
these sequences will be one instruction, sometimes they'll be several.

I therefore wanted a convenient way of matching the exact assembly
implementation of a given function.  It's possible to do that using
single scan-assembler lines, but:

(a) they become hard to read for multiline matches
(b) the PASS/FAIL lines tend to be overly long
(c) it's useful to have a single place that skips over uninteresting
    lines, such as entry block labels and .cfi_* directives, without
    being overly broad

This patch therefore adds a new check-function-bodies dg-final test
that looks for specially-formatted comments.  As a demo, the patch
converts the SVE vec_init tests to use the new harness instead of
scan-assembler.

The regexps in parse_function_bodies are fairly general, but might
still need to be extended in future for targets like Darwin or AIX.

2019-07-29  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* doc/sourcebuild.texi (check-function-bodies): Document.

gcc/testsuite/
	* lib/scanasm.exp (parse_function_bodies, check_function_body)
	(check-function-bodies): New procedures.
	* gcc.target/aarch64/sve/init_1.c: Use check-function-bodies
	instead of scan-assembler.
	* gcc.target/aarch64/sve/init_2.c: Likewise.
	* gcc.target/aarch64/sve/init_3.c: Likewise.
	* gcc.target/aarch64/sve/init_4.c: Likewise.
	* gcc.target/aarch64/sve/init_5.c: Likewise.
	* gcc.target/aarch64/sve/init_6.c: Likewise.
	* gcc.target/aarch64/sve/init_7.c: Likewise.
	* gcc.target/aarch64/sve/init_8.c: Likewise.
	* gcc.target/aarch64/sve/init_9.c: Likewise.
	* gcc.target/aarch64/sve/init_10.c: Likewise.
	* gcc.target/aarch64/sve/init_11.c: Likewise.
	* gcc.target/aarch64/sve/init_12.c: Likewise.

From-SVN: r273869

This patch uses the constant vector encoding scheme to handle
more cases of a VEC_DUPLICATE of another vector.  Duplicating
any fixed-length vector is fine, and duplicating a variable-length
vector is OK as long as that vector is also a duplicate of a
fixed-length sequence.

Other cases fell through to:

  if (VECTOR_MODE_P (mode) && GET_CODE (op) == CONST_VECTOR)

which was only expecting to deal with elementwise operations.

2019-07-29  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* simplify-rtx.c (simplify_const_unary_operation): Fold a
	VEC_DUPLICATE of a fixed-length vector even if the result
	is variable-length.  Likewise fold a duplicate of a
	variable-length vector if the variable-length vector is
	itself a duplicate of a fixed-length sequence.
	(test_vector_ops_duplicate): Test more cases.

From-SVN: r273868

This patch extends the tree-level folding of variable-length vectors
so that it can also be used on rtxes.  The first step is to move
the tree_vector_builder new_unary/binary_operator routines to the
parent vector_builder class (which in turn means adding a new
template parameter).  The second step is to make simplify-rtx.c
use a direct rtx analogue of the VECTOR_CST handling in fold-const.c.

2019-07-29  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* vector-builder.h (vector_builder): Add a shape template parameter.
	(vector_builder::new_unary_operation): New function, generalizing
	the old tree_vector_builder function.
	(vector_builder::new_binary_operation): Likewise.
	(vector_builder::binary_encoded_nelts): Likewise.
	* int-vector-builder.h (int_vector_builder): Update template
	parameters to vector_builder.
	(int_vector_builder::shape_nelts): New function.
	* rtx-vector-builder.h (rtx_vector_builder): Update template
	parameters to vector_builder.
	(rtx_vector_builder::shape_nelts): New function.
	(rtx_vector_builder::nelts_of): Likewise.
	(rtx_vector_builder::npatterns_of): Likewise.
	(rtx_vector_builder::nelts_per_pattern_of): Likewise.
	* tree-vector-builder.h (tree_vector_builder): Update template
	parameters to vector_builder.
	(tree_vector_builder::shape_nelts): New function.
	(tree_vector_builder::nelts_of): Likewise.
	(tree_vector_builder::npatterns_of): Likewise.
	(tree_vector_builder::nelts_per_pattern_of): Likewise.
	* tree-vector-builder.c (tree_vector_builder::new_unary_operation)
	(tree_vector_builder::new_binary_operation): Delete.
	(tree_vector_builder::binary_encoded_nelts): Likewise.
	* simplify-rtx.c: Include rtx-vector-builder.h.
	(distributes_over_addition_p): New function.
	(simplify_const_unary_operation)
	(simplify_const_binary_operation): Generalize handling of vector
	constants to include variable-length vectors.
	(test_vector_ops_series): Add more tests.

From-SVN: r273867

re PR c++/91222 (507.cactuBSSN_r build fails in warn_types_mismatch at ipa-devirt.c:1006 since r273571)


	PR lto/91222
	* ipa-devirt.c (warn_types_mismatch): Compare indentifiers
	than INDENTIFIER_POINTER.

From-SVN: r273866

From-SVN: r273864

2019-07-28  Martin Liska  <mliska@suse.cz>

	PR ipa/89330
	* cgraph.c (symbol_table::create_edge): Always allocate
	a cgraph_edge.
	(symbol_table::free_edge): Store summary_id to
	edge_released_summary_ids if != -1;
	* cgraph.h (NEXT_FREE_NODE): Remove.
	(SET_NEXT_FREE_NODE): Likewise.
	(NEXT_FREE_EDGE): Likewise.
	(symbol_table::release_symbol): Store summary_id to
	cgraph_released_summary_ids if != -1;
	(symbol_table::allocate_cgraph_symbol): Always allocate
	a cgraph_node.

From-SVN: r273857

	* g++.dg/lto/pr89330_0.C (dg-lto-options): Add -fPIC.
	Require fpic support.

From-SVN: r273856

Since svn r123193 (git 327202e27a) the comment about scratch regs was
no longer correct, and I think gen_sibcall could have been used even
then.

	* gcc/config/rs6000/rs6000-call.c (rs6000_output_mi_thunk): Use
	gen_sibcall.

From-SVN: r273855

This patch makes the obvious fix for PR91135, and deletes extraneous
copies of GNU_USER_TARGET_D_OS_VERSIONS that appear in rs6000/linux.h
and rs6000/linux64.h.  Since all configurations using either of these
files also include linux.h there is no need to duplicate the macro.

	PR target/91135
	* config/rs6000/linux.h (GNU_USER_TARGET_D_OS_VERSIONS): Don't
	define.
	* config/rs6000/linux64.h (TARGET_OS_CPP_BUILTINS): Invoke
	GNU_USER_TARGET_OS_CPP_BUILTINS for aixdesc abi.
	(GNU_USER_TARGET_D_OS_VERSIONS): Don't define.

From-SVN: r273854

When gcc is configured using --with-cpu=<cpu>, the specified cpu
effectively becomes a default -mcpu=<cpu> passed to gcc.  This then
affects the cpu passed to gas via ASM_CPU_SPEC.  If gcc is not
configured using --with-cpu then the cpu passed to gas is that given
by ASM_DEFAULT_SPEC, which currently does not match the default flags
selected in default64.h.  This patch makes ASM_DEFAULT_SPEC agree with
TARGET_DEFAULT flags.

rs6000/default64.h appears in three places in config.gcc, the first
one immediately followed by rs6000/freebsd64.h in $tm_file, and the
other two immediately followed by rs6000/linux64.h.  To be able to
define ASM_DEFAULT_SPEC in rs6000/default64.h we don't want to
redefine in the other two files.  rs6000/freebsd64.h is easy since
that file is always preceded by rs6000/default64.h, but
rs6000/linux64.h can appear without rs6000/default64.h (a
powerpc*-linux config where the default is -m32).  In that case we
will have TARGET_DEFAULT flags of 0 (from rs6000/sysv4.h) and want to
use -mppc without -m64 and -mppc64 with -m64.  This can be done by
using the rs6000/rtems.h ASM_DEFAULT_SPEC in rs6000/sysv4.h, a change
that won't affect sysv4 configurations where -m64 is invalid.

The patch also introduces ASM_DEFAULT_EXTRA for the altivec variant
targets so as to enable -maltivec by default.

	PR target/91050
	* config/rs6000/sysv4.h (ASM_DEFAULT_SPEC): Modify if -m64.
	* config/rs6000/default64.h (ASM_DEFAULT_SPEC): Define.
	* config/rs6000/freebsd64.h (ASM_DEFAULT_SPEC): Don't define.
	* config/rs6000/linux64.h (ASM_DEFAULT_SPEC): Likewise.
	* config/rs6000/rtems.h (ASM_DEFAULT_SPEC): Likewise.
	* config/rs6000/rs6000.h (ASM_DEFAULT_EXTRA): Define and use
	in asm_default spec.
	* config/rs6000/eabialtivec.h (ASM_DEFAULT_EXTRA): Redefine.
	* config/rs6000/linuxaltivec.h (ASM_DEFAULT_EXTRA): Redefine.

From-SVN: r273853

	* doc/xml/manual/documentation_hacking.xml: Fix broken reference
	to the Doxygen manual. Avoid a "here" link on the way.
	Fix another broken link to Doxygen docblocks.

From-SVN: r273852

From-SVN: r273851

From-SVN: r273850