In the r10-7197-gbae7b38c commit I've
noticed duplicated word in a message, which lead me to grep for those and
we have a tons of them.
I've used
grep -v 'long long\|optab optab\|template template\|double double' *.[chS] */*.[chS] *.def config/*/* 2>/dev/null | grep ' \([a-zA-Z]\+\) \1 '
Note, the command will not detect the doubled words at the start or end of
line or when one of the words is at the end of line and the next one at the
start of another one.
Some of it is fairly obvious, e.g. all the "the the" cases which is
something I've posted and committed patch for already e.g. in 2016,
other cases are often valid, e.g. "that that" seems to look mostly ok to me.
Some cases are quite hard to figure out, I've left out some of them from the
patch (e.g. "and and" in some cases isn't talking about bitwise/logical and
and so looks incorrect, but in other cases it is talking about those
operations).
In most cases the right solution seems to be to remove one of the duplicated
words, but not always.

I think most important are the ones with user visible messages (in the patch
3 of the first 4 hunks), the rest is just comments (and internal
documentation; for that see the doc/tm.texi changes).

2020-03-17  Jakub Jelinek  <jakub@redhat.com>

	* lra-spills.c (remove_pseudos): Fix up duplicated word issue in
	a dump message.
	* tree-sra.c (create_access_replacement): Fix up duplicated word issue
	in a comment.
	* read-rtl-function.c (find_param_by_name,
	function_reader::parse_enum_value, function_reader::get_insn_by_uid):
	Likewise.
	* spellcheck.c (get_edit_distance_cutoff): Likewise.
	* tree-data-ref.c (create_ifn_alias_checks): Likewise.
	* tree.def (SWITCH_EXPR): Likewise.
	* selftest.c (assert_str_contains): Likewise.
	* ipa-param-manipulation.h (class ipa_param_body_adjustments):
	Likewise.
	* tree-ssa-math-opts.c (convert_expand_mult_copysign): Likewise.
	* tree-ssa-loop-split.c (find_vdef_in_loop): Likewise.
	* langhooks.h (struct lang_hooks_for_decls): Likewise.
	* ipa-prop.h (struct ipa_param_descriptor): Likewise.
	* tree-ssa-strlen.c (handle_builtin_string_cmp, handle_store):
	Likewise.
	* tree-ssa-dom.c (simplify_stmt_for_jump_threading): Likewise.
	* tree-ssa-reassoc.c (reassociate_bb): Likewise.
	* tree.c (component_ref_size): Likewise.
	* hsa-common.c (hsa_init_compilation_unit_data): Likewise.
	* gimple-ssa-sprintf.c (get_string_length, format_string,
	format_directive): Likewise.
	* omp-grid.c (grid_process_kernel_body_copy): Likewise.
	* input.c (string_concat_db::get_string_concatenation,
	test_lexer_string_locations_ucn4): Likewise.
	* cfgexpand.c (pass_expand::execute): Likewise.
	* gimple-ssa-warn-restrict.c (builtin_memref::offset_out_of_bounds,
	maybe_diag_overlap): Likewise.
	* rtl.c (RTX_CODE_HWINT_P_1): Likewise.
	* shrink-wrap.c (spread_components): Likewise.
	* tree-ssa-dse.c (initialize_ao_ref_for_dse, valid_ao_ref_for_dse):
	Likewise.
	* tree-call-cdce.c (shrink_wrap_one_built_in_call_with_conds):
	Likewise.
	* dwarf2out.c (dwarf2out_early_finish): Likewise.
	* gimple-ssa-store-merging.c: Likewise.
	* ira-costs.c (record_operand_costs): Likewise.
	* tree-vect-loop.c (vectorizable_reduction): Likewise.
	* target.def (dispatch): Likewise.
	(validate_dims, gen_ccmp_first): Fix up duplicated word issue
	in documentation text.
	* doc/tm.texi: Regenerated.
	* config/i386/x86-tune.def (X86_TUNE_PARTIAL_FLAG_REG_STALL): Fix up
	duplicated word issue in a comment.
	* config/i386/i386.c (ix86_test_loading_unspec): Likewise.
	* config/i386/i386-features.c (remove_partial_avx_dependency):
	Likewise.
	* config/msp430/msp430.c (msp430_select_section): Likewise.
	* config/gcn/gcn-run.c (load_image): Likewise.
	* config/aarch64/aarch64-sve.md (sve_ld1r<mode>): Likewise.
	* config/aarch64/aarch64.c (aarch64_gen_adjusted_ldpstp): Likewise.
	* config/aarch64/falkor-tag-collision-avoidance.c
	(single_dest_per_chain): Likewise.
	* config/nvptx/nvptx.c (nvptx_record_fndecl): Likewise.
	* config/fr30/fr30.c (fr30_arg_partial_bytes): Likewise.
	* config/rs6000/rs6000-string.c (expand_cmp_vec_sequence): Likewise.
	* config/rs6000/rs6000-p8swap.c (replace_swapped_load_constant):
	Likewise.
	* config/rs6000/rs6000-c.c (rs6000_target_modify_macros): Likewise.
	* config/rs6000/rs6000.c (rs6000_option_override_internal): Likewise.
	* config/rs6000/rs6000-logue.c
	(rs6000_emit_probe_stack_range_stack_clash): Likewise.
	* config/nds32/nds32-md-auxiliary.c (nds32_split_ashiftdi3): Likewise.
	Fix various other issues in the comment.
c-family/
	* c-common.c (resolve_overloaded_builtin): Fix up duplicated word
	issue in a diagnostic message.
cp/
	* pt.c (tsubst): Fix up duplicated word issue in a diagnostic message.
	(lookup_template_class_1, tsubst_expr): Fix up duplicated word issue
	in a comment.
	* parser.c (cp_parser_statement, cp_parser_linkage_specification,
	cp_parser_placeholder_type_specifier,
	cp_parser_constraint_requires_parens): Likewise.
	* name-lookup.c (suggest_alternative_in_explicit_scope): Likewise.
fortran/
	* array.c (gfc_check_iter_variable): Fix up duplicated word issue
	in a comment.
	* arith.c (gfc_arith_concat): Likewise.
	* resolve.c (gfc_resolve_ref): Likewise.
	* frontend-passes.c (matmul_lhs_realloc): Likewise.
	* module.c (gfc_match_submodule, load_needed): Likewise.
	* trans-expr.c (gfc_init_se): Likewise.