common.opt: New option.
[gcc.git] / gcc / common.opt
1 ; Options for the language- and target-independent parts of the compiler.
2
3 ; Copyright (C) 2003-2014 Free Software Foundation, Inc.
4 ;
5 ; This file is part of GCC.
6 ;
7 ; GCC is free software; you can redistribute it and/or modify it under
8 ; the terms of the GNU General Public License as published by the Free
9 ; Software Foundation; either version 3, or (at your option) any later
10 ; version.
11 ;
12 ; GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 ; WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 ; FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 ; for more details.
16 ;
17 ; You should have received a copy of the GNU General Public License
18 ; along with GCC; see the file COPYING3. If not see
19 ; <http://www.gnu.org/licenses/>.
20
21 ; See the GCC internals manual (options.texi) for a description of this file's format.
22
23 ; Please try to keep this file in ASCII collating order.
24
25 Variable
26 int target_flags
27
28 Variable
29 int optimize
30
31 Variable
32 int optimize_size
33
34 Variable
35 int optimize_debug
36
37 ; Not used directly to control optimizations, only to save -Ofast
38 ; setting for "optimize" attributes.
39 Variable
40 int optimize_fast
41
42 ; True if this is the lto front end. This is used to disable gimple
43 ; generation and lowering passes that are normally run on the output
44 ; of a front end. These passes must be bypassed for lto since they
45 ; have already been done before the gimple was written.
46 Variable
47 bool in_lto_p = false
48
49 ; 0 means straightforward implementation of complex divide acceptable.
50 ; 1 means wide ranges of inputs must work for complex divide.
51 ; 2 means C99-like requirements for complex multiply and divide.
52 Variable
53 int flag_complex_method = 1
54
55 ; Nonzero if subexpressions must be evaluated from left-to-right.
56 Variable
57 int flag_evaluation_order = 0
58
59 ; Language specific warning pass for unused results.
60 Variable
61 bool flag_warn_unused_result = false
62
63 Variable
64 int *param_values
65
66 ; Nonzero if we should write GIMPLE bytecode for link-time optimization.
67 Variable
68 int flag_generate_lto
69
70 ; True to warn about any objects definitions whose size is larger
71 ; than N bytes. Also want about function definitions whose returned
72 ; values are larger than N bytes, where N is 'larger_than_size'.
73 Variable
74 bool warn_larger_than
75
76 Variable
77 HOST_WIDE_INT larger_than_size
78
79 ; True to warn about any function whose frame size is larger
80 ; than N bytes.
81 Variable
82 bool warn_frame_larger_than
83
84 Variable
85 HOST_WIDE_INT frame_larger_than_size
86
87 ; Nonzero means we should be saving declaration info into a .X file.
88 Variable
89 int flag_gen_aux_info = 0
90
91 ; Nonzero if we are compiling code for a shared library, zero for
92 ; executable.
93 Variable
94 int flag_shlib
95
96 ; These two are really VEC(char_p,heap) *.
97
98 Variable
99 void *flag_instrument_functions_exclude_functions
100
101 Variable
102 void *flag_instrument_functions_exclude_files
103
104 ; Generic structs (e.g. templates not explicitly specialized)
105 ; may not have a compilation unit associated with them, and so
106 ; may need to be treated differently from ordinary structs.
107 ;
108 ; Structs only handled by reference (indirectly), will also usually
109 ; not need as much debugging information.
110
111 Variable
112 enum debug_struct_file debug_struct_ordinary[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
113
114 Variable
115 enum debug_struct_file debug_struct_generic[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
116
117 ; True if we should exit after parsing options.
118 Variable
119 bool exit_after_options
120
121 ; Type(s) of debugging information we are producing (if any). See
122 ; flag-types.h for the definitions of the different possible types of
123 ; debugging information.
124 Variable
125 enum debug_info_type write_symbols = NO_DEBUG
126
127 ; Level of debugging information we are producing. See flag-types.h
128 ; for the definitions of the different possible levels.
129 Variable
130 enum debug_info_levels debug_info_level = DINFO_LEVEL_NONE
131
132 ; Nonzero means use GNU-only extensions in the generated symbolic
133 ; debugging information. Currently, this only has an effect when
134 ; write_symbols is set to DBX_DEBUG, XCOFF_DEBUG, or DWARF_DEBUG.
135 Variable
136 bool use_gnu_debug_info_extensions
137
138 ; Original value of maximum field alignment in bytes, specified via
139 ; -fpack-struct=<value>.
140 Variable
141 unsigned int initial_max_fld_align = TARGET_DEFAULT_PACK_STRUCT
142
143 ; Type of stack check.
144 Variable
145 enum stack_check_type flag_stack_check = NO_STACK_CHECK
146
147 ; True if stack usage information needs to be computed.
148 Variable
149 bool flag_stack_usage_info = false
150
151 ; -dA causes debug commentary information to be produced in
152 ; the generated assembly code (to make it more readable). This option
153 ; is generally only of use to those who actually need to read the
154 ; generated assembly code (perhaps while debugging the compiler itself).
155 ; Currently, this switch is only used by dwarf2out.c; however, it is intended
156 ; to be a catchall for printing debug information in the assembler file.
157 Variable
158 int flag_debug_asm
159
160 ; -dP causes the rtl to be emitted as a comment in assembly.
161 Variable
162 int flag_dump_rtl_in_asm
163
164 ; Whether -da was passed (used only in handle_common_deferred_options).
165 Variable
166 bool flag_dump_all_passed
167
168 ; Other flags saying which kinds of debugging dump have been requested.
169
170 Variable
171 int rtl_dump_and_exit
172
173 Variable
174 int flag_print_asm_name
175
176 ; Name of top-level original source file (what was input to cpp).
177 ; This comes from the #-command at the beginning of the actual input.
178 ; If there isn't any there, then this is the cc1 input file name.
179 Variable
180 const char *main_input_filename
181
182 ; Pointer to base name in main_input_filename, with directories and a
183 ; single final extension removed, and the length of this base
184 ; name.
185
186 Variable
187 const char *main_input_basename
188
189 Variable
190 int main_input_baselength
191
192 ; Which options have been printed by --help.
193 Variable
194 char *help_printed
195
196 ; Which enums have been printed by --help. 0 = not printed, no
197 ; relevant options seen, 1 = relevant option seen, not yet printed, 2
198 ; = printed.
199 Variable
200 char *help_enum_printed
201
202 ; The number of columns for --help output.
203 Variable
204 unsigned int help_columns
205
206 ; Whether this options structure has been through finish_options
207 Variable
208 bool flag_opts_finished
209
210 ; What the sanitizer should instrument
211 Variable
212 unsigned int flag_sanitize
213
214 ; Flag whether a prefix has been added to dump_base_name
215 Variable
216 bool dump_base_name_prefixed = false
217
218 ###
219 Driver
220
221 -assemble
222 Driver Alias(S)
223
224 -compile
225 Driver Alias(c)
226
227 -coverage
228 Driver Alias(coverage)
229
230 -debug
231 Common Alias(g)
232
233 -dump
234 Common Separate Alias(d)
235
236 -dump=
237 Common Joined Alias(d)
238
239 -dumpbase
240 Common Separate Alias(dumpbase)
241
242 -dumpdir
243 Common Separate Alias(dumpdir)
244
245 -entry
246 Driver Separate Alias(e)
247
248 -entry=
249 Driver Joined Alias(e)
250
251 -extra-warnings
252 Common Warning Alias(Wextra)
253
254 -for-assembler
255 Driver Separate Alias(Xassembler)
256
257 -for-assembler=
258 Driver JoinedOrMissing Alias(Xassembler)
259
260 -for-linker
261 Driver Separate Alias(Xlinker)
262
263 -for-linker=
264 Driver JoinedOrMissing Alias(Xlinker)
265
266 -force-link
267 Driver Separate Alias(u)
268
269 -force-link=
270 Driver Joined Alias(u)
271
272 -help
273 Common Driver Var(help_flag)
274 Display this information
275
276 -help=
277 Common Driver Report Joined
278 --help=<class> Display descriptions of a specific class of options. <class> is one or more of optimizers, target, warnings, undocumented, params
279
280 -language
281 Driver Separate Alias(x)
282
283 -language=
284 Driver Joined Alias(x)
285
286 -library-directory
287 Driver Separate Alias(L)
288
289 -library-directory=
290 Driver Joined Alias(L)
291
292 -no-canonical-prefixes
293 Driver Alias(no-canonical-prefixes)
294
295 -no-standard-libraries
296 Driver Alias(nostdlib)
297
298 -no-sysroot-suffix
299 Driver Var(no_sysroot_suffix)
300
301 -no-warnings
302 Common Alias(w)
303
304 -optimize
305 Common Alias(O)
306
307 -output
308 Common Driver Separate Alias(o) MissingArgError(missing filename after %qs)
309
310 -output=
311 Common Driver Joined Alias(o) MissingArgError(missing filename after %qs)
312
313 -pass-exit-codes
314 Driver Alias(pass-exit-codes)
315
316 -pedantic
317 Common Alias(Wpedantic)
318
319 -pedantic-errors
320 Common Alias(pedantic-errors)
321
322 -pie
323 Driver Alias(pie)
324
325 -pipe
326 Driver Alias(pipe)
327
328 -prefix
329 Driver Separate Alias(B)
330
331 -prefix=
332 Driver JoinedOrMissing Alias(B)
333
334 -preprocess
335 Driver Alias(E)
336
337 -print-file-name
338 Driver Separate Alias(print-file-name=)
339
340 -print-file-name=
341 Driver JoinedOrMissing Alias(print-file-name=)
342
343 -print-libgcc-file-name
344 Driver Alias(print-libgcc-file-name)
345
346 -print-multi-directory
347 Driver Alias(print-multi-directory)
348
349 -print-multi-lib
350 Driver Alias(print-multi-lib)
351
352 -print-multi-os-directory
353 Driver Alias(print-multi-os-directory)
354
355 -print-multiarch
356 Driver Alias(print-multiarch)
357
358 -print-prog-name
359 Driver Separate Alias(print-prog-name=)
360
361 -print-prog-name=
362 Driver JoinedOrMissing Alias(print-prog-name=)
363
364 -print-search-dirs
365 Driver Alias(print-search-dirs)
366
367 -print-sysroot
368 Driver Alias(print-sysroot)
369
370 -print-sysroot-headers-suffix
371 Driver Alias(print-sysroot-headers-suffix)
372
373 -profile
374 Common Alias(p)
375
376 -save-temps
377 Driver Alias(save-temps)
378
379 -shared
380 Driver Alias(shared)
381
382 -specs
383 Driver Separate Alias(specs=)
384
385 -specs=
386 Driver Joined Alias(specs=)
387
388 -static
389 Driver Alias(static)
390
391 -symbolic
392 Driver Alias(symbolic)
393
394 -target-help
395 Common Driver
396 Alias for --help=target
397
398 -time
399 Driver Alias(time)
400
401 -verbose
402 Driver Alias(v)
403
404 ;; The driver used to convert options such as --help into forms such
405 ;; as -fhelp; the following four entries are for compatibility with
406 ;; any direct uses of those (undocumented) -f forms
407 fhelp
408 Common Driver Alias(-help)
409
410 fhelp=
411 Common Driver Joined Alias(-help=)
412
413 ftarget-help
414 Common Driver Alias(-target-help)
415
416 fversion
417 Common Driver Alias(-version)
418
419 -param
420 Common Separate
421 --param <param>=<value> Set parameter <param> to value. See below for a complete list of parameters
422
423 -param=
424 Common Joined Alias(-param)
425
426 -sysroot
427 Driver Separate Alias(-sysroot=)
428
429 -sysroot=
430 Driver JoinedOrMissing
431
432 -version
433 Common Driver
434
435 B
436 Driver Joined Separate
437
438 E
439 Driver
440
441 L
442 Driver Joined Separate
443
444 N
445 Driver
446
447 O
448 Common JoinedOrMissing Optimization
449 -O<number> Set optimization level to <number>
450
451 Os
452 Common Optimization
453 Optimize for space rather than speed
454
455 Ofast
456 Common Optimization
457 Optimize for speed disregarding exact standards compliance
458
459 Og
460 Common Optimization
461 Optimize for debugging experience rather than speed or size
462
463 Q
464 Driver
465
466 Qn
467 Driver Negative(Qy)
468
469 Qy
470 Driver Negative(Qn)
471
472 R
473 Driver Joined Separate
474
475 S
476 Driver
477
478 T
479 Driver Joined Separate
480
481 Tbss
482 Driver Separate
483
484 Tbss=
485 Driver Joined
486
487 Tdata
488 Driver Separate
489
490 Tdata=
491 Driver Joined
492
493 Ttext
494 Driver Separate
495
496 Ttext=
497 Driver Joined
498
499 W
500 Common RejectNegative Warning Alias(Wextra)
501 This switch is deprecated; use -Wextra instead
502
503 Wa,
504 Driver JoinedOrMissing
505
506 Wl,
507 Driver JoinedOrMissing
508
509 Wp,
510 Driver JoinedOrMissing
511
512 Waggregate-return
513 Common Var(warn_aggregate_return) Warning
514 Warn about returning structures, unions or arrays
515
516 Waggressive-loop-optimizations
517 Common Var(warn_aggressive_loop_optimizations) Init(1) Warning
518 Warn if a loop with constant number of iterations triggers undefined behavior
519
520 Warray-bounds
521 Common Var(warn_array_bounds) Warning
522 Warn if an array is accessed out of bounds
523
524 Wattributes
525 Common Var(warn_attributes) Init(1) Warning
526 Warn about inappropriate attribute usage
527
528 Wcast-align
529 Common Var(warn_cast_align) Warning
530 Warn about pointer casts which increase alignment
531
532 Wcpp
533 Common Var(warn_cpp) Init(1) Warning
534 Warn when a #warning directive is encountered
535
536 Wdeprecated-declarations
537 Common Var(warn_deprecated_decl) Init(1) Warning
538 Warn about uses of __attribute__((deprecated)) declarations
539
540 Wdisabled-optimization
541 Common Var(warn_disabled_optimization) Warning
542 Warn when an optimization pass is disabled
543
544 Werror
545 Common Var(warnings_are_errors)
546 Treat all warnings as errors
547
548 Werror=
549 Common Joined
550 Treat specified warning as error
551
552 Wextra
553 Common Var(extra_warnings) Warning
554 Print extra (possibly unwanted) warnings
555
556 Wfatal-errors
557 Common Var(flag_fatal_errors)
558 Exit on the first error occurred
559
560 Wframe-larger-than=
561 Common RejectNegative Joined UInteger
562 -Wframe-larger-than=<number> Warn if a function's stack frame requires more than <number> bytes
563
564 Wfree-nonheap-object
565 Common Var(warn_free_nonheap_object) Init(1) Warning
566 Warn when attempting to free a non-heap object
567
568 Winline
569 Common Var(warn_inline) Warning
570 Warn when an inlined function cannot be inlined
571
572 Winvalid-memory-model
573 Common Var(warn_invalid_memory_model) Init(1) Warning
574 Warn when an atomic memory model parameter is known to be outside the valid range.
575
576 Wlarger-than-
577 Common RejectNegative Joined Warning Undocumented Alias(Wlarger-than=)
578
579 Wlarger-than=
580 Common RejectNegative Joined UInteger Warning
581 -Wlarger-than=<number> Warn if an object is larger than <number> bytes
582
583 Wunsafe-loop-optimizations
584 Common Var(warn_unsafe_loop_optimizations) Warning
585 Warn if the loop cannot be optimized due to nontrivial assumptions.
586
587 Wmissing-noreturn
588 Common Alias(Wsuggest-attribute=noreturn)
589
590 Wodr
591 Common Var(warn_odr_violations) Init(1) Warning
592 Warn about some C++ One Definition Rule violations during link time optimization
593
594 Woverflow
595 Common Var(warn_overflow) Init(1) Warning
596 Warn about overflow in arithmetic expressions
597
598 Wpacked
599 Common Var(warn_packed) Warning
600 Warn when the packed attribute has no effect on struct layout
601
602 Wpadded
603 Common Var(warn_padded) Warning
604 Warn when padding is required to align structure members
605
606 Wpedantic
607 Common Var(pedantic) Init(0) Warning
608 Issue warnings needed for strict compliance to the standard
609
610 Wreturn-local-addr
611 Common Var(warn_return_local_addr) Init(1) Warning
612 Warn about returning a pointer/reference to a local or temporary variable.
613
614 Wshadow
615 Common Var(warn_shadow) Warning
616 Warn when one local variable shadows another
617
618 Wstack-protector
619 Common Var(warn_stack_protect) Warning
620 Warn when not issuing stack smashing protection for some reason
621
622 Wstack-usage=
623 Common Joined RejectNegative UInteger Var(warn_stack_usage) Init(-1) Warning
624 Warn if stack usage might be larger than specified amount
625
626 Wstrict-aliasing
627 Common Warning
628 Warn about code which might break strict aliasing rules
629
630 Wstrict-aliasing=
631 Common Joined RejectNegative UInteger Var(warn_strict_aliasing) Warning
632 Warn about code which might break strict aliasing rules
633
634 Wstrict-overflow
635 Common Warning
636 Warn about optimizations that assume that signed overflow is undefined
637
638 Wstrict-overflow=
639 Common Joined RejectNegative UInteger Var(warn_strict_overflow) Warning
640 Warn about optimizations that assume that signed overflow is undefined
641
642 Wsuggest-attribute=const
643 Common Var(warn_suggest_attribute_const) Warning
644 Warn about functions which might be candidates for __attribute__((const))
645
646 Wsuggest-attribute=pure
647 Common Var(warn_suggest_attribute_pure) Warning
648 Warn about functions which might be candidates for __attribute__((pure))
649
650 Wsuggest-attribute=noreturn
651 Common Var(warn_suggest_attribute_noreturn) Warning
652 Warn about functions which might be candidates for __attribute__((noreturn))
653
654 Wsuggest-final-types
655 Common Var(warn_suggest_final_types) Warning
656 Warn about C++ polymorphic types where adding final keyword would improve code quality
657
658 Wsuggest-final-methods
659 Common Var(warn_suggest_final_methods) Warning
660 Warn about C++ virtual methods where adding final keyword would improve code quality
661
662 Wsystem-headers
663 Common Var(warn_system_headers) Warning
664 Do not suppress warnings from system headers
665
666 Wtrampolines
667 Common Var(warn_trampolines) Warning
668 Warn whenever a trampoline is generated
669
670 Wtype-limits
671 Common Var(warn_type_limits) Warning EnabledBy(Wextra)
672 Warn if a comparison is always true or always false due to the limited range of the data type
673
674 Wuninitialized
675 Common Var(warn_uninitialized) Warning EnabledBy(Wextra)
676 Warn about uninitialized automatic variables
677
678 Wmaybe-uninitialized
679 Common Var(warn_maybe_uninitialized) Warning EnabledBy(Wuninitialized)
680 Warn about maybe uninitialized automatic variables
681
682 Wunreachable-code
683 Common Ignore
684 Does nothing. Preserved for backward compatibility.
685
686 Wunused
687 Common Var(warn_unused) Init(0) Warning
688 Enable all -Wunused- warnings
689
690 Wunused-but-set-parameter
691 Common Var(warn_unused_but_set_parameter) Warning EnabledBy(Wunused && Wextra)
692 Warn when a function parameter is only set, otherwise unused
693
694 Wunused-but-set-variable
695 Common Var(warn_unused_but_set_variable) Warning EnabledBy(Wunused)
696 Warn when a variable is only set, otherwise unused
697
698 Wunused-function
699 Common Var(warn_unused_function) Warning EnabledBy(Wunused)
700 Warn when a function is unused
701
702 Wunused-label
703 Common Var(warn_unused_label) Warning EnabledBy(Wunused)
704 Warn when a label is unused
705
706 Wunused-parameter
707 Common Var(warn_unused_parameter) Warning EnabledBy(Wunused && Wextra)
708 Warn when a function parameter is unused
709
710 Wunused-value
711 Common Var(warn_unused_value) Warning EnabledBy(Wunused)
712 Warn when an expression value is unused
713
714 Wunused-variable
715 Common Var(warn_unused_variable) Warning EnabledBy(Wunused)
716 Warn when a variable is unused
717
718 Wcoverage-mismatch
719 Common Var(warn_coverage_mismatch) Init(1) Warning
720 Warn in case profiles in -fprofile-use do not match
721
722 Wvector-operation-performance
723 Common Var(warn_vector_operation_performance) Warning
724 Warn when a vector operation is compiled outside the SIMD
725
726 Xassembler
727 Driver Separate
728
729 Xlinker
730 Driver Separate
731
732 Xpreprocessor
733 Driver Separate
734
735 Z
736 Driver
737
738 aux-info
739 Common Separate Var(aux_info_file_name)
740 -aux-info <file> Emit declaration information into <file>
741
742 aux-info=
743 Common Joined Alias(aux-info)
744
745 auxbase
746 Common Separate RejectDriver Var(aux_base_name)
747
748 auxbase-strip
749 Common Separate RejectDriver
750
751 coverage
752 Driver
753
754 c
755 Driver
756
757 d
758 Common Joined
759 -d<letters> Enable dumps from specific passes of the compiler
760
761 dumpbase
762 Common Separate Var(dump_base_name)
763 -dumpbase <file> Set the file basename to be used for dumps
764
765 dumpdir
766 Common Separate Var(dump_dir_name)
767 -dumpdir <dir> Set the directory name to be used for dumps
768
769 dumpmachine
770 Driver
771
772 dumpspecs
773 Driver
774
775 dumpversion
776 Driver
777
778 e
779 Driver Joined Separate
780
781 ; This option has historically been passed down to the linker by an
782 ; accident of a %{e*} spec, so ensure it continues to be passed down
783 ; as a single option. The supported option for this purpose is
784 ; -rdynamic. See PR 47390.
785 export-dynamic
786 Driver Undocumented
787
788 ; The version of the C++ ABI in use. The following values are allowed:
789 ;
790 ; 0: The version of the ABI believed most conformant with the C++ ABI
791 ; specification. This ABI may change as bugs are discovered and fixed.
792 ; Therefore, 0 will not necessarily indicate the same ABI in different
793 ; versions of G++.
794 ;
795 ; 1: The version of the ABI first used in G++ 3.2. No longer selectable.
796 ;
797 ; 2: The version of the ABI first used in G++ 3.4 (and current default).
798 ;
799 ; 3: The version of the ABI that fixes the missing underscore
800 ; in template non-type arguments of pointer type.
801 ;
802 ; 4: The version of the ABI that introduces unambiguous mangling of
803 ; vector types. First selectable in G++ 4.5.
804 ;
805 ; 5: The version of the ABI that ignores attribute const/noreturn
806 ; in function pointer mangling, and corrects mangling of decltype and
807 ; function parameters used in other parameters and the return type.
808 ; First selectable in G++ 4.6.
809 ;
810 ; 6: The version of the ABI that doesn't promote scoped enums to int and
811 ; changes the mangling of template argument packs, const/static_cast,
812 ; prefix ++ and --, and a class scope function used as a template
813 ; argument.
814 ; First selectable in G++ 4.7.
815 ;
816 ; 7: The version of the ABI that treats nullptr_t as a builtin type and
817 ; corrects the mangling of lambdas in default argument scope.
818 ; First selectable in G++ 4.8.
819 ;
820 ; 8: The version of the ABI that corrects the substitution behavior of
821 ; function types with function-cv-qualifiers.
822 ; First selectable in G++ 4.9.
823 ;
824 ; Additional positive integers will be assigned as new versions of
825 ; the ABI become the default version of the ABI.
826 fabi-version=
827 Common Joined RejectNegative UInteger Var(flag_abi_version) Init(0)
828 The version of the C++ ABI in use
829
830 faggressive-loop-optimizations
831 Common Report Var(flag_aggressive_loop_optimizations) Optimization Init(1)
832 Aggressively optimize loops using language constraints
833
834 falign-functions
835 Common Report Var(align_functions,0) Optimization UInteger
836 Align the start of functions
837
838 falign-functions=
839 Common RejectNegative Joined UInteger Var(align_functions)
840
841 falign-jumps
842 Common Report Var(align_jumps,0) Optimization UInteger
843 Align labels which are only reached by jumping
844
845 falign-jumps=
846 Common RejectNegative Joined UInteger Var(align_jumps)
847
848 falign-labels
849 Common Report Var(align_labels,0) Optimization UInteger
850 Align all labels
851
852 falign-labels=
853 Common RejectNegative Joined UInteger Var(align_labels)
854
855 falign-loops
856 Common Report Var(align_loops,0) Optimization UInteger
857 Align the start of loops
858
859 falign-loops=
860 Common RejectNegative Joined UInteger Var(align_loops)
861
862 fargument-alias
863 Common Ignore
864 Does nothing. Preserved for backward compatibility.
865
866 fargument-noalias
867 Common Ignore
868 Does nothing. Preserved for backward compatibility.
869
870 fargument-noalias-global
871 Common Ignore
872 Does nothing. Preserved for backward compatibility.
873
874 fargument-noalias-anything
875 Common Ignore
876 Does nothing. Preserved for backward compatibility.
877
878 fsanitize=
879 Common Driver Report Joined
880 Select what to sanitize
881
882 fsanitize-recover
883 Common Report Var(flag_sanitize_recover) Init(1)
884 After diagnosing undefined behavior attempt to continue execution
885
886 fsanitize-undefined-trap-on-error
887 Common Report Var(flag_sanitize_undefined_trap_on_error) Init(0)
888 Use trap instead of a library function for undefined behavior sanitization
889
890 fasynchronous-unwind-tables
891 Common Report Var(flag_asynchronous_unwind_tables) Optimization
892 Generate unwind tables that are exact at each instruction boundary
893
894 fauto-inc-dec
895 Common Report Var(flag_auto_inc_dec) Init(1)
896 Generate auto-inc/dec instructions
897
898 ; -fcheck-bounds causes gcc to generate array bounds checks.
899 ; For C, C++ and ObjC: defaults off.
900 ; For Java: defaults to on.
901 ; For Fortran: defaults to off.
902 fbounds-check
903 Common Report Var(flag_bounds_check)
904 Generate code to check bounds before indexing arrays
905
906 fbranch-count-reg
907 Common Report Var(flag_branch_on_count_reg) Optimization
908 Replace add, compare, branch with branch on count register
909
910 fbranch-probabilities
911 Common Report Var(flag_branch_probabilities) Optimization
912 Use profiling information for branch probabilities
913
914 fbranch-target-load-optimize
915 Common Report Var(flag_branch_target_load_optimize) Optimization
916 Perform branch target load optimization before prologue / epilogue threading
917
918 fbranch-target-load-optimize2
919 Common Report Var(flag_branch_target_load_optimize2) Optimization
920 Perform branch target load optimization after prologue / epilogue threading
921
922 fbtr-bb-exclusive
923 Common Report Var(flag_btr_bb_exclusive) Optimization
924 Restrict target load migration not to re-use registers in any basic block
925
926 fcall-saved-
927 Common Joined RejectNegative Var(common_deferred_options) Defer
928 -fcall-saved-<register> Mark <register> as being preserved across functions
929
930 fcall-used-
931 Common Joined RejectNegative Var(common_deferred_options) Defer
932 -fcall-used-<register> Mark <register> as being corrupted by function calls
933
934 ; Nonzero for -fcaller-saves: allocate values in regs that need to
935 ; be saved across function calls, if that produces overall better code.
936 ; Optional now, so people can test it.
937 fcaller-saves
938 Common Report Var(flag_caller_saves) Optimization
939 Save registers around function calls
940
941 fcheck-data-deps
942 Common Report Var(flag_check_data_deps)
943 Compare the results of several data dependence analyzers.
944
945 fcheck-new
946 Common Var(flag_check_new)
947 Check the return value of new in C++
948
949 fcombine-stack-adjustments
950 Common Report Var(flag_combine_stack_adjustments) Optimization
951 Looks for opportunities to reduce stack adjustments and stack references.
952
953 fcommon
954 Common Report Var(flag_no_common,0) Optimization
955 Do not put uninitialized globals in the common section
956
957 fcompare-debug
958 Driver
959 ; Converted by the driver to -fcompare-debug= options.
960
961 fcompare-debug=
962 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
963 -fcompare-debug[=<opts>] Compile with and without e.g. -gtoggle, and compare the final-insns dump
964
965 fcompare-debug-second
966 Common Driver RejectNegative Var(flag_compare_debug)
967 Run only the second compilation of -fcompare-debug
968
969 fcompare-elim
970 Common Report Var(flag_compare_elim_after_reload) Optimization
971 Perform comparison elimination after register allocation has finished
972
973 fconserve-stack
974 Common Var(flag_conserve_stack) Optimization
975 Do not perform optimizations increasing noticeably stack usage
976
977 fcprop-registers
978 Common Report Var(flag_cprop_registers) Optimization
979 Perform a register copy-propagation optimization pass
980
981 fcrossjumping
982 Common Report Var(flag_crossjumping) Optimization
983 Perform cross-jumping optimization
984
985 fcse-follow-jumps
986 Common Report Var(flag_cse_follow_jumps) Optimization
987 When running CSE, follow jumps to their targets
988
989 fcse-skip-blocks
990 Common Ignore
991 Does nothing. Preserved for backward compatibility.
992
993 fcx-limited-range
994 Common Report Var(flag_cx_limited_range) Optimization SetByCombined
995 Omit range reduction step when performing complex division
996
997 fcx-fortran-rules
998 Common Report Var(flag_cx_fortran_rules) Optimization
999 Complex multiplication and division follow Fortran rules
1000
1001 fdata-sections
1002 Common Report Var(flag_data_sections) Optimization
1003 Place data items into their own section
1004
1005 fdbg-cnt-list
1006 Common Report Var(common_deferred_options) Defer
1007 List all available debugging counters with their limits and counts.
1008
1009 fdbg-cnt=
1010 Common RejectNegative Joined Var(common_deferred_options) Defer
1011 -fdbg-cnt=<counter>:<limit>[,<counter>:<limit>,...] Set the debug counter limit.
1012
1013 fdebug-prefix-map=
1014 Common Joined RejectNegative Var(common_deferred_options) Defer
1015 Map one directory name to another in debug information
1016
1017 fdebug-types-section
1018 Common Report Var(flag_debug_types_section) Init(0)
1019 Output .debug_types section when using DWARF v4 debuginfo.
1020
1021 ; Nonzero for -fdefer-pop: don't pop args after each function call
1022 ; instead save them up to pop many calls' args with one insns.
1023 fdefer-pop
1024 Common Report Var(flag_defer_pop) Optimization
1025 Defer popping functions args from stack until later
1026
1027 fdelayed-branch
1028 Common Report Var(flag_delayed_branch) Optimization
1029 Attempt to fill delay slots of branch instructions
1030
1031 fdelete-dead-exceptions
1032 Common Report Var(flag_delete_dead_exceptions) Init(0)
1033 Delete dead instructions that may throw exceptions
1034
1035 fdelete-null-pointer-checks
1036 Common Report Var(flag_delete_null_pointer_checks) Init(1) Optimization
1037 Delete useless null pointer checks
1038
1039 fdevirtualize-speculatively
1040 Common Report Var(flag_devirtualize_speculatively) Optimization
1041 Perform speculative devirtualization
1042
1043 fdevirtualize
1044 Common Report Var(flag_devirtualize) Optimization
1045 Try to convert virtual calls to direct ones.
1046
1047 fdiagnostics-show-location=
1048 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
1049 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics
1050
1051 ; Required for these enum values.
1052 SourceInclude
1053 pretty-print.h
1054
1055 Enum
1056 Name(diagnostic_prefixing_rule) Type(int)
1057
1058 EnumValue
1059 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1060
1061 EnumValue
1062 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1063
1064 fdiagnostics-show-caret
1065 Common Var(flag_diagnostics_show_caret) Init(1)
1066 Show the source line with a caret indicating the column
1067
1068 fdiagnostics-color
1069 Common Alias(fdiagnostics-color=,always,never)
1070 ;
1071
1072 fdiagnostics-color=
1073 Common Joined RejectNegative Var(flag_diagnostics_show_color) Enum(diagnostic_color_rule) Init(DIAGNOSTICS_COLOR_NO)
1074 -fdiagnostics-color=[never|always|auto] Colorize diagnostics
1075
1076 ; Required for these enum values.
1077 SourceInclude
1078 diagnostic-color.h
1079
1080 Enum
1081 Name(diagnostic_color_rule) Type(int)
1082
1083 EnumValue
1084 Enum(diagnostic_color_rule) String(never) Value(DIAGNOSTICS_COLOR_NO)
1085
1086 EnumValue
1087 Enum(diagnostic_color_rule) String(always) Value(DIAGNOSTICS_COLOR_YES)
1088
1089 EnumValue
1090 Enum(diagnostic_color_rule) String(auto) Value(DIAGNOSTICS_COLOR_AUTO)
1091
1092 fdiagnostics-show-option
1093 Common Var(flag_diagnostics_show_option) Init(1)
1094 Amend appropriate diagnostic messages with the command line option that controls them
1095
1096 fdisable-
1097 Common Joined RejectNegative Var(common_deferred_options) Defer
1098 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 disables an optimization pass
1099
1100 fenable-
1101 Common Joined RejectNegative Var(common_deferred_options) Defer
1102 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 enables an optimization pass
1103
1104 fdump-
1105 Common Joined RejectNegative Var(common_deferred_options) Defer
1106 -fdump-<type> Dump various compiler internals to a file
1107
1108 fdump-final-insns
1109 Driver RejectNegative
1110
1111 fdump-final-insns=
1112 Common RejectNegative Joined Var(flag_dump_final_insns)
1113 -fdump-final-insns=filename Dump to filename the insns at the end of translation
1114
1115 fdump-go-spec=
1116 Common RejectNegative Joined Var(flag_dump_go_spec)
1117 -fdump-go-spec=filename Write all declarations to file as Go code
1118
1119 fdump-noaddr
1120 Common Report Var(flag_dump_noaddr)
1121 Suppress output of addresses in debugging dumps
1122
1123 freport-bug
1124 Common Driver Var(flag_report_bug)
1125 Collect and dump debug information into temporary file if ICE in C/C++
1126 compiler occured.
1127
1128 fdump-passes
1129 Common Var(flag_dump_passes) Init(0)
1130 Dump optimization passes
1131
1132 fdump-unnumbered
1133 Common Report Var(flag_dump_unnumbered)
1134 Suppress output of instruction numbers, line number notes and addresses in debugging dumps
1135
1136 fdump-unnumbered-links
1137 Common Report Var(flag_dump_unnumbered_links)
1138 Suppress output of previous and next insn numbers in debugging dumps
1139
1140 fdwarf2-cfi-asm
1141 Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1142 Enable CFI tables via GAS assembler directives.
1143
1144 fearly-inlining
1145 Common Report Var(flag_early_inlining) Init(1) Optimization
1146 Perform early inlining
1147
1148 feliminate-dwarf2-dups
1149 Common Report Var(flag_eliminate_dwarf2_dups)
1150 Perform DWARF2 duplicate elimination
1151
1152 fipa-sra
1153 Common Report Var(flag_ipa_sra) Init(0) Optimization
1154 Perform interprocedural reduction of aggregates
1155
1156 feliminate-unused-debug-symbols
1157 Common Report Var(flag_debug_only_used_symbols)
1158 Perform unused type elimination in debug info
1159
1160 feliminate-unused-debug-types
1161 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
1162 Perform unused type elimination in debug info
1163
1164 femit-class-debug-always
1165 Common Report Var(flag_emit_class_debug_always) Init(0)
1166 Do not suppress C++ class debug information.
1167
1168 fexceptions
1169 Common Report Var(flag_exceptions) Optimization
1170 Enable exception handling
1171
1172 fexpensive-optimizations
1173 Common Report Var(flag_expensive_optimizations) Optimization
1174 Perform a number of minor, expensive optimizations
1175
1176 fexcess-precision=
1177 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision_cmdline) Init(EXCESS_PRECISION_DEFAULT)
1178 -fexcess-precision=[fast|standard] Specify handling of excess floating-point precision
1179
1180 Enum
1181 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1182
1183 EnumValue
1184 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1185
1186 EnumValue
1187 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1188
1189 ffast-math
1190 Common
1191
1192 ffat-lto-objects
1193 Common Var(flag_fat_lto_objects)
1194 Output lto objects containing both the intermediate language and binary output.
1195
1196 ffinite-math-only
1197 Common Report Var(flag_finite_math_only) Optimization SetByCombined
1198 Assume no NaNs or infinities are generated
1199
1200 ffixed-
1201 Common Joined RejectNegative Var(common_deferred_options) Defer
1202 -ffixed-<register> Mark <register> as being unavailable to the compiler
1203
1204 ffloat-store
1205 Common Report Var(flag_float_store) Optimization
1206 Don't allocate floats and doubles in extended-precision registers
1207
1208 fforce-addr
1209 Common Ignore
1210 Does nothing. Preserved for backward compatibility.
1211
1212 fforward-propagate
1213 Common Report Var(flag_forward_propagate) Optimization
1214 Perform a forward propagation pass on RTL
1215
1216 ffp-contract=
1217 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST)
1218 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1219
1220 Enum
1221 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1222
1223 EnumValue
1224 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1225
1226 ; Not implemented, fall back to conservative FP_CONTRACT_OFF.
1227 EnumValue
1228 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_OFF)
1229
1230 EnumValue
1231 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1232
1233 ; Nonzero means don't put addresses of constant functions in registers.
1234 ; Used for compiling the Unix kernel, where strange substitutions are
1235 ; done on the assembly output.
1236 ffunction-cse
1237 Common Report Var(flag_no_function_cse,0)
1238 Allow function addresses to be held in registers
1239
1240 ffunction-sections
1241 Common Report Var(flag_function_sections)
1242 Place each function into its own section
1243
1244 fgcse
1245 Common Report Var(flag_gcse) Optimization
1246 Perform global common subexpression elimination
1247
1248 fgcse-lm
1249 Common Report Var(flag_gcse_lm) Init(1) Optimization
1250 Perform enhanced load motion during global common subexpression elimination
1251
1252 fgcse-sm
1253 Common Report Var(flag_gcse_sm) Init(0) Optimization
1254 Perform store motion after global common subexpression elimination
1255
1256 fgcse-las
1257 Common Report Var(flag_gcse_las) Init(0) Optimization
1258 Perform redundant load after store elimination in global common subexpression
1259 elimination
1260
1261 fgcse-after-reload
1262 Common Report Var(flag_gcse_after_reload) Optimization
1263 Perform global common subexpression elimination after register allocation
1264 has finished
1265
1266 ; This option is not documented yet as its semantics will change.
1267 fgraphite
1268 Common Report Var(flag_graphite)
1269 Enable in and out of Graphite representation
1270
1271 fgraphite-identity
1272 Common Report Var(flag_graphite_identity) Optimization
1273 Enable Graphite Identity transformation
1274
1275 fgraphite-code-generator=
1276 Common Report RejectNegative Joined Optimization Enum(fgraphite_generator) Var(flag_graphite_code_gen) Init(FGRAPHITE_CODE_GEN_ISL)
1277 Choose code generator of Graphite
1278
1279 Enum
1280 Name(fgraphite_generator) Type(enum fgraphite_generator) UnknownError(unknown code generator of graphite %qs)
1281
1282 EnumValue
1283 Enum(fgraphite_generator) String(isl) Value(FGRAPHITE_CODE_GEN_ISL)
1284
1285 EnumValue
1286 Enum(fgraphite_generator) String(cloog) Value(FGRAPHITE_CODE_GEN_CLOOG)
1287
1288 fhoist-adjacent-loads
1289 Common Report Var(flag_hoist_adjacent_loads) Optimization
1290 Enable hoisting adjacent loads to encourage generating conditional move
1291 instructions
1292
1293 floop-parallelize-all
1294 Common Report Var(flag_loop_parallelize_all) Optimization
1295 Mark all loops as parallel
1296
1297 floop-strip-mine
1298 Common Report Var(flag_loop_strip_mine) Optimization
1299 Enable Loop Strip Mining transformation
1300
1301 floop-interchange
1302 Common Report Var(flag_loop_interchange) Optimization
1303 Enable Loop Interchange transformation
1304
1305 floop-block
1306 Common Report Var(flag_loop_block) Optimization
1307 Enable Loop Blocking transformation
1308
1309 fgnu-tm
1310 Common Report Var(flag_tm)
1311 Enable support for GNU transactional memory
1312
1313 fgnu-unique
1314 Common Report Var(flag_gnu_unique) Init(1)
1315 Use STB_GNU_UNIQUE if supported by the assembler
1316
1317 floop-flatten
1318 Common Ignore
1319 Does nothing. Preserved for backward compatibility.
1320
1321 floop-nest-optimize
1322 Common Report Var(flag_loop_optimize_isl) Optimization
1323 Enable the ISL based loop nest optimizer
1324
1325 fstrict-volatile-bitfields
1326 Common Report Var(flag_strict_volatile_bitfields) Init(-1)
1327 Force bitfield accesses to match their type width
1328
1329 fguess-branch-probability
1330 Common Report Var(flag_guess_branch_prob) Optimization
1331 Enable guessing of branch probabilities
1332
1333 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1334 ; Generate position-independent code for executables if possible
1335 ; On SVR4 targets, it also controls whether or not to emit a
1336 ; string identifying the compiler.
1337 fident
1338 Common Report Var(flag_no_ident,0)
1339 Process #ident directives
1340
1341 fif-conversion
1342 Common Report Var(flag_if_conversion) Optimization
1343 Perform conversion of conditional jumps to branchless equivalents
1344
1345 fif-conversion2
1346 Common Report Var(flag_if_conversion2) Optimization
1347 Perform conversion of conditional jumps to conditional execution
1348
1349 fstack-reuse=
1350 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL)
1351 -fstack-reuse=[all|named_vars|none] Set stack reuse level for local variables.
1352
1353 Enum
1354 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1355
1356 EnumValue
1357 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1358
1359 EnumValue
1360 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1361
1362 EnumValue
1363 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1364
1365 ftree-loop-if-convert
1366 Common Report Var(flag_tree_loop_if_convert) Init(-1) Optimization
1367 Convert conditional jumps in innermost loops to branchless equivalents
1368
1369 ftree-loop-if-convert-stores
1370 Common Report Var(flag_tree_loop_if_convert_stores) Optimization
1371 Also if-convert conditional jumps containing memory writes
1372
1373 ; -finhibit-size-directive inhibits output of .size for ELF.
1374 ; This is used only for compiling crtstuff.c,
1375 ; and it may be extended to other effects
1376 ; needed for crtstuff.c on other systems.
1377 finhibit-size-directive
1378 Common Report Var(flag_inhibit_size_directive)
1379 Do not generate .size directives
1380
1381 findirect-inlining
1382 Common Report Var(flag_indirect_inlining)
1383 Perform indirect inlining
1384
1385 ; General flag to enable inlining. Specifying -fno-inline will disable
1386 ; all inlining apart from always-inline functions.
1387 finline
1388 Common Report Var(flag_no_inline,0) Init(0) Optimization
1389 Enable inlining of function declared \"inline\", disabling disables all inlining
1390
1391 finline-small-functions
1392 Common Report Var(flag_inline_small_functions) Optimization
1393 Integrate functions into their callers when code size is known not to grow
1394
1395 finline-functions
1396 Common Report Var(flag_inline_functions) Optimization
1397 Integrate functions not declared \"inline\" into their callers when profitable
1398
1399 finline-functions-called-once
1400 Common Report Var(flag_inline_functions_called_once) Optimization
1401 Integrate functions only required by their single caller
1402
1403 finline-limit-
1404 Common RejectNegative Joined Alias(finline-limit=)
1405
1406 finline-limit=
1407 Common RejectNegative Joined UInteger
1408 -finline-limit=<number> Limit the size of inlined functions to <number>
1409
1410 finline-atomics
1411 Common Report Var(flag_inline_atomics) Init(1) Optimization
1412 Inline __atomic operations when a lock free instruction sequence is available.
1413
1414 finstrument-functions
1415 Common Report Var(flag_instrument_function_entry_exit)
1416 Instrument function entry and exit with profiling calls
1417
1418 finstrument-functions-exclude-function-list=
1419 Common RejectNegative Joined
1420 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions
1421
1422 finstrument-functions-exclude-file-list=
1423 Common RejectNegative Joined
1424 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files
1425
1426 fipa-cp
1427 Common Report Var(flag_ipa_cp) Optimization
1428 Perform interprocedural constant propagation
1429
1430 fipa-cp-clone
1431 Common Report Var(flag_ipa_cp_clone) Optimization
1432 Perform cloning to make Interprocedural constant propagation stronger
1433
1434 fipa-profile
1435 Common Report Var(flag_ipa_profile) Init(0) Optimization
1436 Perform interprocedural profile propagation
1437
1438 fipa-pta
1439 Common Report Var(flag_ipa_pta) Init(0) Optimization
1440 Perform interprocedural points-to analysis
1441
1442 fipa-pure-const
1443 Common Report Var(flag_ipa_pure_const) Init(0) Optimization
1444 Discover pure and const functions
1445
1446 fipa-reference
1447 Common Report Var(flag_ipa_reference) Init(0) Optimization
1448 Discover readonly and non addressable static variables
1449
1450 fipa-matrix-reorg
1451 Common Ignore
1452 Does nothing. Preserved for backward compatibility.
1453
1454 fipa-struct-reorg
1455 Common Ignore
1456 Does nothing. Preserved for backward compatibility.
1457
1458 fira-algorithm=
1459 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB)
1460 -fira-algorithm=[CB|priority] Set the used IRA algorithm
1461
1462 Enum
1463 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
1464
1465 EnumValue
1466 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
1467
1468 EnumValue
1469 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
1470
1471 fira-region=
1472 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_AUTODETECT)
1473 -fira-region=[one|all|mixed] Set regions for IRA
1474
1475 Enum
1476 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
1477
1478 EnumValue
1479 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
1480
1481 EnumValue
1482 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
1483
1484 EnumValue
1485 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
1486
1487 fira-hoist-pressure
1488 Common Report Var(flag_ira_hoist_pressure) Init(1) Optimization
1489 Use IRA based register pressure calculation
1490 in RTL hoist optimizations.
1491
1492 fira-loop-pressure
1493 Common Report Var(flag_ira_loop_pressure) Optimization
1494 Use IRA based register pressure calculation
1495 in RTL loop optimizations.
1496
1497 fira-share-save-slots
1498 Common Report Var(flag_ira_share_save_slots) Init(1)
1499 Share slots for saving different hard registers.
1500
1501 fira-share-spill-slots
1502 Common Report Var(flag_ira_share_spill_slots) Init(1)
1503 Share stack slots for spilled pseudo-registers.
1504
1505 fira-verbose=
1506 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
1507 -fira-verbose=<number> Control IRA's level of diagnostic messages.
1508
1509 fivopts
1510 Common Report Var(flag_ivopts) Init(1) Optimization
1511 Optimize induction variables on trees
1512
1513 fjump-tables
1514 Common Var(flag_jump_tables) Init(1) Optimization
1515 Use jump tables for sufficiently large switch statements
1516
1517 fkeep-inline-functions
1518 Common Report Var(flag_keep_inline_functions)
1519 Generate code for functions even if they are fully inlined
1520
1521 fkeep-static-consts
1522 Common Report Var(flag_keep_static_consts) Init(1)
1523 Emit static const variables even if they are not used
1524
1525 fleading-underscore
1526 Common Report Var(flag_leading_underscore) Init(-1)
1527 Give external symbols a leading underscore
1528
1529 floop-optimize
1530 Common Ignore
1531 Does nothing. Preserved for backward compatibility.
1532
1533 flto
1534 Common
1535 Enable link-time optimization.
1536
1537 flto=
1538 Common RejectNegative Joined Var(flag_lto)
1539 Link-time optimization with number of parallel jobs or jobserver.
1540
1541 Enum
1542 Name(lto_partition_model) Type(enum lto_partition_model) UnknownError(unknown LTO partitioning model %qs)
1543
1544 EnumValue
1545 Enum(lto_partition_model) String(none) Value(LTO_PARTITION_NONE)
1546
1547 EnumValue
1548 Enum(lto_partition_model) String(one) Value(LTO_PARTITION_ONE)
1549
1550 EnumValue
1551 Enum(lto_partition_model) String(balanced) Value(LTO_PARTITION_BALANCED)
1552
1553 EnumValue
1554 Enum(lto_partition_model) String(1to1) Value(LTO_PARTITION_1TO1)
1555
1556 EnumValue
1557 Enum(lto_partition_model) String(max) Value(LTO_PARTITION_MAX)
1558
1559 flto-partition=
1560 Common Joined RejectNegative Enum(lto_partition_model) Var(flag_lto_partition) Init(LTO_PARTITION_BALANCED)
1561 Specify the algorithm to partition symbols and vars at linktime
1562
1563 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
1564 flto-compression-level=
1565 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1)
1566 -flto-compression-level=<number> Use zlib compression level <number> for IL
1567
1568 flto-odr-type-merging
1569 Common Report Var(flag_lto_odr_type_mering) Init(1)
1570 Merge C++ types using One Definition Rule
1571
1572 flto-report
1573 Common Report Var(flag_lto_report) Init(0)
1574 Report various link-time optimization statistics
1575
1576 flto-report-wpa
1577 Common Report Var(flag_lto_report_wpa) Init(0)
1578 Report various link-time optimization statistics for WPA only
1579
1580 fmath-errno
1581 Common Report Var(flag_errno_math) Init(1) Optimization SetByCombined
1582 Set errno after built-in math functions
1583
1584 fmax-errors=
1585 Common Joined RejectNegative UInteger Var(flag_max_errors)
1586 -fmax-errors=<number> Maximum number of errors to report
1587
1588 fmem-report
1589 Common Report Var(mem_report)
1590 Report on permanent memory allocation
1591
1592 fmem-report-wpa
1593 Common Report Var(mem_report_wpa)
1594 Report on permanent memory allocation in WPA only
1595
1596 ; This will attempt to merge constant section constants, if 1 only
1597 ; string constants and constants from constant pool, if 2 also constant
1598 ; variables.
1599 fmerge-all-constants
1600 Common Report Var(flag_merge_constants,2) Init(1) Optimization
1601 Attempt to merge identical constants and constant variables
1602
1603 fmerge-constants
1604 Common Report Var(flag_merge_constants,1) Optimization
1605 Attempt to merge identical constants across compilation units
1606
1607 fmerge-debug-strings
1608 Common Report Var(flag_merge_debug_strings) Init(1)
1609 Attempt to merge identical debug strings across compilation units
1610
1611 fmessage-length=
1612 Common RejectNegative Joined UInteger
1613 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping
1614
1615 fmodulo-sched
1616 Common Report Var(flag_modulo_sched) Optimization
1617 Perform SMS based modulo scheduling before the first scheduling pass
1618
1619 fmodulo-sched-allow-regmoves
1620 Common Report Var(flag_modulo_sched_allow_regmoves)
1621 Perform SMS based modulo scheduling with register moves allowed
1622
1623 fmove-loop-invariants
1624 Common Report Var(flag_move_loop_invariants) Optimization
1625 Move loop invariant computations out of loops
1626
1627 fdce
1628 Common Var(flag_dce) Init(1) Optimization
1629 Use the RTL dead code elimination pass
1630
1631 fdse
1632 Common Var(flag_dse) Init(1) Optimization
1633 Use the RTL dead store elimination pass
1634
1635 freschedule-modulo-scheduled-loops
1636 Common Report Var(flag_resched_modulo_sched) Optimization
1637 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling
1638
1639 fnon-call-exceptions
1640 Common Report Var(flag_non_call_exceptions) Optimization
1641 Support synchronous non-call exceptions
1642
1643 fomit-frame-pointer
1644 Common Report Var(flag_omit_frame_pointer) Optimization
1645 When possible do not generate stack frames
1646
1647 fopt-info
1648 Common Report Var(flag_opt_info) Optimization
1649 Enable all optimization info dumps on stderr
1650
1651 fopt-info-
1652 Common Joined RejectNegative Var(common_deferred_options) Defer
1653 -fopt-info[-<type>=filename] Dump compiler optimization details
1654
1655 foptimize-register-move
1656 Common Ignore
1657 Does nothing. Preserved for backward compatibility.
1658
1659 foptimize-sibling-calls
1660 Common Report Var(flag_optimize_sibling_calls) Optimization
1661 Optimize sibling and tail recursive calls
1662
1663 fpartial-inlining
1664 Common Report Var(flag_partial_inlining)
1665 Perform partial inlining
1666
1667 fpre-ipa-mem-report
1668 Common Report Var(pre_ipa_mem_report)
1669 Report on memory allocation before interprocedural optimization
1670
1671 fpost-ipa-mem-report
1672 Common Report Var(post_ipa_mem_report)
1673 Report on memory allocation before interprocedural optimization
1674
1675 fpack-struct
1676 Common Report Var(flag_pack_struct) Optimization
1677 Pack structure members together without holes
1678
1679 fpack-struct=
1680 Common RejectNegative Joined UInteger Optimization
1681 -fpack-struct=<number> Set initial maximum structure member alignment
1682
1683 fpcc-struct-return
1684 Common Report Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
1685 Return small aggregates in memory, not registers
1686
1687 fpeel-loops
1688 Common Report Var(flag_peel_loops) Optimization
1689 Perform loop peeling
1690
1691 fpeephole
1692 Common Report Var(flag_no_peephole,0) Optimization
1693 Enable machine specific peephole optimizations
1694
1695 fpeephole2
1696 Common Report Var(flag_peephole2) Optimization
1697 Enable an RTL peephole pass before sched2
1698
1699 fPIC
1700 Common Report Var(flag_pic,2) Negative(fPIE)
1701 Generate position-independent code if possible (large mode)
1702
1703 fPIE
1704 Common Report Var(flag_pie,2) Negative(fpic)
1705 Generate position-independent code for executables if possible (large mode)
1706
1707 fpic
1708 Common Report Var(flag_pic,1) Negative(fpie)
1709 Generate position-independent code if possible (small mode)
1710
1711 fpie
1712 Common Report Var(flag_pie,1) Negative(fPIC)
1713 Generate position-independent code for executables if possible (small mode)
1714
1715 fplugin=
1716 Common Joined RejectNegative Var(common_deferred_options) Defer
1717 Specify a plugin to load
1718
1719 fplugin-arg-
1720 Common Joined RejectNegative Var(common_deferred_options) Defer
1721 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>
1722
1723 fpredictive-commoning
1724 Common Report Var(flag_predictive_commoning) Optimization
1725 Run predictive commoning optimization.
1726
1727 fprefetch-loop-arrays
1728 Common Report Var(flag_prefetch_loop_arrays) Init(-1) Optimization
1729 Generate prefetch instructions, if available, for arrays in loops
1730
1731 fprofile
1732 Common Report Var(profile_flag)
1733 Enable basic program profiling code
1734
1735 fprofile-arcs
1736 Common Report Var(profile_arc_flag)
1737 Insert arc-based program profiling code
1738
1739 fprofile-dir=
1740 Common Joined RejectNegative Var(profile_data_prefix)
1741 Set the top-level directory for storing the profile data.
1742 The default is 'pwd'.
1743
1744 fprofile-correction
1745 Common Report Var(flag_profile_correction)
1746 Enable correction of flow inconsistent profile data input
1747
1748 fprofile-generate
1749 Common
1750 Enable common options for generating profile info for profile feedback directed optimizations
1751
1752 fprofile-generate=
1753 Common Joined RejectNegative
1754 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=
1755
1756 fprofile-use
1757 Common Var(flag_profile_use)
1758 Enable common options for performing profile feedback directed optimizations
1759
1760 fprofile-use=
1761 Common Joined RejectNegative
1762 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=
1763
1764 fprofile-values
1765 Common Report Var(flag_profile_values)
1766 Insert code to profile values of expressions
1767
1768 fprofile-report
1769 Common Report Var(profile_report)
1770 Report on consistency of profile
1771
1772 fprofile-reorder-functions
1773 Common Report Var(flag_profile_reorder_functions)
1774 Enable function reordering that improves code placement
1775
1776 frandom-seed
1777 Common Var(common_deferred_options) Defer
1778
1779 frandom-seed=
1780 Common Joined RejectNegative Var(common_deferred_options) Defer
1781 -frandom-seed=<string> Make compile reproducible using <string>
1782
1783 ; This switch causes the command line that was used to create an
1784 ; object file to be recorded into the object file. The exact format
1785 ; of this recording is target and binary file format dependent.
1786 ; It is related to the -fverbose-asm switch, but that switch only
1787 ; records information in the assembler output file as comments, so
1788 ; they never reach the object file.
1789 frecord-gcc-switches
1790 Common Report Var(flag_record_gcc_switches)
1791 Record gcc command line switches in the object file.
1792
1793 freg-struct-return
1794 Common Report Var(flag_pcc_struct_return,0) Optimization
1795 Return small aggregates in registers
1796
1797 fregmove
1798 Common Ignore
1799 Does nothing. Preserved for backward compatibility.
1800
1801 flive-range-shrinkage
1802 Common Report Var(flag_live_range_shrinkage) Init(0) Optimization
1803 Relief of register pressure through live range shrinkage
1804
1805 frename-registers
1806 Common Report Var(flag_rename_registers) Init(2) Optimization
1807 Perform a register renaming optimization pass
1808
1809 freorder-blocks
1810 Common Report Var(flag_reorder_blocks) Optimization
1811 Reorder basic blocks to improve code placement
1812
1813 freorder-blocks-and-partition
1814 Common Report Var(flag_reorder_blocks_and_partition) Optimization
1815 Reorder basic blocks and partition into hot and cold sections
1816
1817 freorder-functions
1818 Common Report Var(flag_reorder_functions) Optimization
1819 Reorder functions to improve code placement
1820
1821 frerun-cse-after-loop
1822 Common Report Var(flag_rerun_cse_after_loop) Optimization
1823 Add a common subexpression elimination pass after loop optimizations
1824
1825 frerun-loop-opt
1826 Common Ignore
1827 Does nothing. Preserved for backward compatibility.
1828
1829 frounding-math
1830 Common Report Var(flag_rounding_math) Optimization SetByCombined
1831 Disable optimizations that assume default FP rounding behavior
1832
1833 fsched-interblock
1834 Common Report Var(flag_schedule_interblock) Init(1) Optimization
1835 Enable scheduling across basic blocks
1836
1837 fsched-pressure
1838 Common Report Var(flag_sched_pressure) Init(0) Optimization
1839 Enable register pressure sensitive insn scheduling
1840
1841 fsched-spec
1842 Common Report Var(flag_schedule_speculative) Init(1) Optimization
1843 Allow speculative motion of non-loads
1844
1845 fsched-spec-load
1846 Common Report Var(flag_schedule_speculative_load) Optimization
1847 Allow speculative motion of some loads
1848
1849 fsched-spec-load-dangerous
1850 Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
1851 Allow speculative motion of more loads
1852
1853 fsched-verbose=
1854 Common RejectNegative Joined UInteger Var(sched_verbose_param)
1855 -fsched-verbose=<number> Set the verbosity level of the scheduler
1856
1857 fsched2-use-superblocks
1858 Common Report Var(flag_sched2_use_superblocks) Optimization
1859 If scheduling post reload, do superblock scheduling
1860
1861 fsched2-use-traces
1862 Common Ignore
1863 Does nothing. Preserved for backward compatibility.
1864
1865 fschedule-insns
1866 Common Report Var(flag_schedule_insns) Optimization
1867 Reschedule instructions before register allocation
1868
1869 fschedule-insns2
1870 Common Report Var(flag_schedule_insns_after_reload) Optimization
1871 Reschedule instructions after register allocation
1872
1873 ; This flag should be on when a target implements non-trivial
1874 ; scheduling hooks, maybe saving some information for its own sake.
1875 ; On IA64, for example, this is used for correct bundling.
1876 fselective-scheduling
1877 Common Report Var(flag_selective_scheduling) Optimization
1878 Schedule instructions using selective scheduling algorithm
1879
1880 fselective-scheduling2
1881 Common Report Var(flag_selective_scheduling2) Optimization
1882 Run selective scheduling after reload
1883
1884 fsel-sched-pipelining
1885 Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization
1886 Perform software pipelining of inner loops during selective scheduling
1887
1888 fsel-sched-pipelining-outer-loops
1889 Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
1890 Perform software pipelining of outer loops during selective scheduling
1891
1892 fsel-sched-reschedule-pipelined
1893 Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
1894 Reschedule pipelined regions without pipelining
1895
1896 fsemantic-interposition
1897 Common Report Var(flag_semantic_interposition) Init(1)
1898 Allow interposing function (or variables) by ones with different semantics (or initializer) respectively by dynamic linker
1899
1900 ; sched_stalled_insns means that insns can be moved prematurely from the queue
1901 ; of stalled insns into the ready list.
1902 fsched-stalled-insns
1903 Common Report Var(flag_sched_stalled_insns) Optimization UInteger
1904 Allow premature scheduling of queued insns
1905
1906 fsched-stalled-insns=
1907 Common RejectNegative Joined UInteger
1908 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled
1909
1910 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
1911 ; be examined for a dependency on a stalled insn that is candidate for
1912 ; premature removal from the queue of stalled insns into the ready list (has
1913 ; an effect only if the flag 'sched_stalled_insns' is set).
1914 fsched-stalled-insns-dep
1915 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
1916 Set dependence distance checking in premature scheduling of queued insns
1917
1918 fsched-stalled-insns-dep=
1919 Common RejectNegative Joined UInteger
1920 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns
1921
1922 fsched-group-heuristic
1923 Common Report Var(flag_sched_group_heuristic) Init(1) Optimization
1924 Enable the group heuristic in the scheduler
1925
1926 fsched-critical-path-heuristic
1927 Common Report Var(flag_sched_critical_path_heuristic) Init(1) Optimization
1928 Enable the critical path heuristic in the scheduler
1929
1930 fsched-spec-insn-heuristic
1931 Common Report Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
1932 Enable the speculative instruction heuristic in the scheduler
1933
1934 fsched-rank-heuristic
1935 Common Report Var(flag_sched_rank_heuristic) Init(1) Optimization
1936 Enable the rank heuristic in the scheduler
1937
1938 fsched-last-insn-heuristic
1939 Common Report Var(flag_sched_last_insn_heuristic) Init(1) Optimization
1940 Enable the last instruction heuristic in the scheduler
1941
1942 fsched-dep-count-heuristic
1943 Common Report Var(flag_sched_dep_count_heuristic) Init(1) Optimization
1944 Enable the dependent count heuristic in the scheduler
1945
1946 fsection-anchors
1947 Common Report Var(flag_section_anchors) Optimization
1948 Access data in the same section from shared anchor points
1949
1950 fsee
1951 Common Ignore
1952 Does nothing. Preserved for backward compatibility.
1953
1954 fzee
1955 Common Ignore
1956 Does nothing. Preserved for backward compatibility.
1957
1958 free
1959 Common Report Var(flag_ree) Init(0)
1960 Turn on Redundant Extensions Elimination pass.
1961
1962 fshow-column
1963 Common Report Var(flag_show_column) Init(1)
1964 Show column numbers in diagnostics, when available. Default on
1965
1966 fshrink-wrap
1967 Common Report Var(flag_shrink_wrap) Optimization
1968 Emit function prologues only before parts of the function that need it,
1969 rather than at the top of the function.
1970
1971 fsignaling-nans
1972 Common Report Var(flag_signaling_nans) Optimization SetByCombined
1973 Disable optimizations observable by IEEE signaling NaNs
1974
1975 fsigned-zeros
1976 Common Report Var(flag_signed_zeros) Init(1) Optimization SetByCombined
1977 Disable floating point optimizations that ignore the IEEE signedness of zero
1978
1979 fsingle-precision-constant
1980 Common Report Var(flag_single_precision_constant) Optimization
1981 Convert floating point constants to single precision constants
1982
1983 fsplit-ivs-in-unroller
1984 Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
1985 Split lifetimes of induction variables when loops are unrolled
1986
1987 fsplit-stack
1988 Common Report Var(flag_split_stack) Init(-1)
1989 Generate discontiguous stack frames
1990
1991 fsplit-wide-types
1992 Common Report Var(flag_split_wide_types) Optimization
1993 Split wide types into independent registers
1994
1995 fssa-phiopt
1996 Common Report Var(flag_ssa_phiopt) Optimization
1997 Optimize conditional patterns using SSA PHI nodes
1998
1999 fvariable-expansion-in-unroller
2000 Common Report Var(flag_variable_expansion_in_unroller) Optimization
2001 Apply variable expansion when loops are unrolled
2002
2003 fstack-check=
2004 Common Report RejectNegative Joined
2005 -fstack-check=[no|generic|specific] Insert stack checking code into the program
2006
2007 fstack-check
2008 Common Alias(fstack-check=, specific, no)
2009 Insert stack checking code into the program. Same as -fstack-check=specific
2010
2011 fstack-limit
2012 Common Var(common_deferred_options) Defer
2013
2014 fstack-limit-register=
2015 Common RejectNegative Joined Var(common_deferred_options) Defer
2016 -fstack-limit-register=<register> Trap if the stack goes past <register>
2017
2018 fstack-limit-symbol=
2019 Common RejectNegative Joined Var(common_deferred_options) Defer
2020 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>
2021
2022 fstack-protector
2023 Common Report Var(flag_stack_protect, 1)
2024 Use propolice as a stack protection method
2025
2026 fstack-protector-all
2027 Common Report RejectNegative Var(flag_stack_protect, 2)
2028 Use a stack protection method for every function
2029
2030 fstack-protector-strong
2031 Common Report RejectNegative Var(flag_stack_protect, 3)
2032 Use a smart stack protection method for certain functions
2033
2034 fstack-usage
2035 Common RejectNegative Var(flag_stack_usage)
2036 Output stack usage information on a per-function basis
2037
2038 fstrength-reduce
2039 Common Ignore
2040 Does nothing. Preserved for backward compatibility.
2041
2042 ; Nonzero if we should do (language-dependent) alias analysis.
2043 ; Typically, this analysis will assume that expressions of certain
2044 ; types do not alias expressions of certain other types. Only used
2045 ; if alias analysis (in general) is enabled.
2046 fstrict-aliasing
2047 Common Report Var(flag_strict_aliasing) Optimization
2048 Assume strict aliasing rules apply
2049
2050 fstrict-overflow
2051 Common Report Var(flag_strict_overflow)
2052 Treat signed overflow as undefined
2053
2054 fsync-libcalls
2055 Common Report Var(flag_sync_libcalls) Init(1)
2056 Implement __atomic operations via libcalls to legacy __sync functions
2057
2058 fsyntax-only
2059 Common Report Var(flag_syntax_only)
2060 Check for syntax errors, then stop
2061
2062 ftest-coverage
2063 Common Report Var(flag_test_coverage)
2064 Create data files needed by \"gcov\"
2065
2066 fthread-jumps
2067 Common Report Var(flag_thread_jumps) Optimization
2068 Perform jump threading optimizations
2069
2070 ftime-report
2071 Common Report Var(time_report)
2072 Report the time taken by each compiler pass
2073
2074 ftls-model=
2075 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
2076 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model
2077
2078 Enum
2079 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
2080
2081 EnumValue
2082 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
2083
2084 EnumValue
2085 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
2086
2087 EnumValue
2088 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
2089
2090 EnumValue
2091 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
2092
2093 ftoplevel-reorder
2094 Common Report Var(flag_toplevel_reorder) Init(2) Optimization
2095 Reorder top level functions, variables, and asms
2096
2097 ftracer
2098 Common Report Var(flag_tracer)
2099 Perform superblock formation via tail duplication
2100
2101 ; Zero means that floating-point math operations cannot generate a
2102 ; (user-visible) trap. This is the case, for example, in nonstop
2103 ; IEEE 754 arithmetic.
2104 ftrapping-math
2105 Common Report Var(flag_trapping_math) Init(1) Optimization SetByCombined
2106 Assume floating-point operations can trap
2107
2108 ftrapv
2109 Common Report Var(flag_trapv) Optimization
2110 Trap for signed overflow in addition, subtraction and multiplication
2111
2112 ftree-ccp
2113 Common Report Var(flag_tree_ccp) Optimization
2114 Enable SSA-CCP optimization on trees
2115
2116 ftree-bit-ccp
2117 Common Report Var(flag_tree_bit_ccp) Optimization
2118 Enable SSA-BIT-CCP optimization on trees
2119
2120 ftree-store-ccp
2121 Common Ignore
2122 Does nothing. Preserved for backward compatibility.
2123
2124 ftree-ch
2125 Common Report Var(flag_tree_ch) Optimization
2126 Enable loop header copying on trees
2127
2128 ftree-coalesce-inlined-vars
2129 Common Report Var(flag_ssa_coalesce_vars,1) Init(2) RejectNegative Optimization
2130 Enable coalescing of copy-related user variables that are inlined
2131
2132 ftree-coalesce-vars
2133 Common Report Var(flag_ssa_coalesce_vars,2) Optimization
2134 Enable coalescing of all copy-related user variables
2135
2136 ftree-copyrename
2137 Common Report Var(flag_tree_copyrename) Optimization
2138 Replace SSA temporaries with better names in copies
2139
2140 ftree-copy-prop
2141 Common Report Var(flag_tree_copy_prop) Optimization
2142 Enable copy propagation on trees
2143
2144 ftree-store-copy-prop
2145 Common Ignore
2146 Does nothing. Preserved for backward compatibility.
2147
2148 ftree-cselim
2149 Common Report Var(flag_tree_cselim) Init(2) Optimization
2150 Transform condition stores into unconditional ones
2151
2152 ftree-switch-conversion
2153 Common Report Var(flag_tree_switch_conversion) Optimization
2154 Perform conversions of switch initializations.
2155
2156 ftree-dce
2157 Common Report Var(flag_tree_dce) Optimization
2158 Enable SSA dead code elimination optimization on trees
2159
2160 ftree-dominator-opts
2161 Common Report Var(flag_tree_dom) Optimization
2162 Enable dominator optimizations
2163
2164 ftree-tail-merge
2165 Common Report Var(flag_tree_tail_merge) Optimization
2166 Enable tail merging on trees
2167
2168 ftree-dse
2169 Common Report Var(flag_tree_dse) Optimization
2170 Enable dead store elimination
2171
2172 ftree-forwprop
2173 Common Report Var(flag_tree_forwprop) Init(1) Optimization
2174 Enable forward propagation on trees
2175
2176 ftree-fre
2177 Common Report Var(flag_tree_fre) Optimization
2178 Enable Full Redundancy Elimination (FRE) on trees
2179
2180 foptimize-strlen
2181 Common Report Var(flag_optimize_strlen) Optimization
2182 Enable string length optimizations on trees
2183
2184 fisolate-erroneous-paths-dereference
2185 Common Report Var(flag_isolate_erroneous_paths_dereference) Optimization
2186 Detect paths which trigger erroneous or undefined behaviour due to
2187 dereferencing a NULL pointer. Isolate those paths from the main control
2188 flow and turn the statement with erroneous or undefined behaviour into a trap.
2189
2190 fisolate-erroneous-paths-attribute
2191 Common Report Var(flag_isolate_erroneous_paths_attribute) Optimization
2192 Detect paths which trigger erroneous or undefined behaviour due a NULL value
2193 being used in a way which is forbidden by a returns_nonnull or nonnull
2194 attribute. Isolate those paths from the main control flow and turn the
2195 statement with erroneous or undefined behaviour into a trap.
2196
2197 ftree-loop-distribution
2198 Common Report Var(flag_tree_loop_distribution) Optimization
2199 Enable loop distribution on trees
2200
2201 ftree-loop-distribute-patterns
2202 Common Report Var(flag_tree_loop_distribute_patterns) Optimization
2203 Enable loop distribution for patterns transformed into a library call
2204
2205 ftree-loop-im
2206 Common Report Var(flag_tree_loop_im) Init(1) Optimization
2207 Enable loop invariant motion on trees
2208
2209 ftree-loop-linear
2210 Common Alias(floop-interchange)
2211 Enable loop interchange transforms. Same as -floop-interchange
2212
2213 ftree-loop-ivcanon
2214 Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
2215 Create canonical induction variables in loops
2216
2217 ftree-loop-optimize
2218 Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
2219 Enable loop optimizations on tree level
2220
2221 ftree-parallelize-loops=
2222 Common Report Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1)
2223 Enable automatic parallelization of loops
2224
2225 ftree-phiprop
2226 Common Report Var(flag_tree_phiprop) Init(1) Optimization
2227 Enable hoisting loads from conditional pointers.
2228
2229 ftree-pre
2230 Common Report Var(flag_tree_pre) Optimization
2231 Enable SSA-PRE optimization on trees
2232
2233 ftree-partial-pre
2234 Common Report Var(flag_tree_partial_pre) Optimization
2235 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination
2236
2237 ftree-pta
2238 Common Report Var(flag_tree_pta) Optimization
2239 Perform function-local points-to analysis on trees.
2240
2241 ftree-reassoc
2242 Common Report Var(flag_tree_reassoc) Init(1) Optimization
2243 Enable reassociation on tree level
2244
2245 ftree-salias
2246 Common Ignore
2247 Does nothing. Preserved for backward compatibility.
2248
2249 ftree-sink
2250 Common Report Var(flag_tree_sink) Optimization
2251 Enable SSA code sinking on trees
2252
2253 ftree-slsr
2254 Common Report Var(flag_tree_slsr) Optimization
2255 Perform straight-line strength reduction
2256
2257 ftree-sra
2258 Common Report Var(flag_tree_sra) Optimization
2259 Perform scalar replacement of aggregates
2260
2261 ftree-ter
2262 Common Report Var(flag_tree_ter) Optimization
2263 Replace temporary expressions in the SSA->normal pass
2264
2265 ftree-lrs
2266 Common Report Var(flag_tree_live_range_split) Optimization
2267 Perform live range splitting during the SSA->normal pass
2268
2269 ftree-vrp
2270 Common Report Var(flag_tree_vrp) Init(0) Optimization
2271 Perform Value Range Propagation on trees
2272
2273 funit-at-a-time
2274 Common Report Var(flag_unit_at_a_time) Init(1) Optimization
2275 Compile whole compilation unit at a time
2276
2277 funroll-loops
2278 Common Report Var(flag_unroll_loops) Optimization
2279 Perform loop unrolling when iteration count is known
2280
2281 funroll-all-loops
2282 Common Report Var(flag_unroll_all_loops) Optimization
2283 Perform loop unrolling for all loops
2284
2285 ; Nonzero means that loop optimizer may assume that the induction variables
2286 ; that control loops do not overflow and that the loops with nontrivial
2287 ; exit condition are not infinite
2288 funsafe-loop-optimizations
2289 Common Report Var(flag_unsafe_loop_optimizations) Optimization
2290 Allow loop optimizations to assume that the loops behave in normal way
2291
2292 fassociative-math
2293 Common Report Var(flag_associative_math) SetByCombined
2294 Allow optimization for floating-point arithmetic which may change the
2295 result of the operation due to rounding.
2296
2297 freciprocal-math
2298 Common Report Var(flag_reciprocal_math) SetByCombined
2299 Same as -fassociative-math for expressions which include division.
2300
2301 ; Nonzero means that unsafe floating-point math optimizations are allowed
2302 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
2303 ; are allowed to assume that their arguments and results are "normal"
2304 ; (e.g., nonnegative for SQRT).
2305 funsafe-math-optimizations
2306 Common Report Var(flag_unsafe_math_optimizations) Optimization SetByCombined
2307 Allow math optimizations that may violate IEEE or ISO standards
2308
2309 funswitch-loops
2310 Common Report Var(flag_unswitch_loops) Optimization
2311 Perform loop unswitching
2312
2313 funwind-tables
2314 Common Report Var(flag_unwind_tables) Optimization
2315 Just generate unwind tables for exception handling
2316
2317 fuse-ld=bfd
2318 Common Driver Negative(fuse-ld=gold)
2319 Use the bfd linker instead of the default linker
2320
2321 fuse-ld=gold
2322 Common Driver Negative(fuse-ld=bfd)
2323 Use the gold linker instead of the default linker
2324
2325 fuse-linker-plugin
2326 Common Undocumented Var(flag_use_linker_plugin)
2327
2328 ; Positive if we should track variables, negative if we should run
2329 ; the var-tracking pass only to discard debug annotations, zero if
2330 ; we're not to run it. When flag_var_tracking == 2 (AUTODETECT_VALUE) it
2331 ; will be set according to optimize, debug_info_level and debug_hooks
2332 ; in process_options ().
2333 fvar-tracking
2334 Common Report Var(flag_var_tracking) Init(2) Optimization
2335 Perform variable tracking
2336
2337 ; Positive if we should track variables at assignments, negative if
2338 ; we should run the var-tracking pass only to discard debug
2339 ; annotations. When flag_var_tracking_assignments ==
2340 ; AUTODETECT_VALUE it will be set according to flag_var_tracking.
2341 fvar-tracking-assignments
2342 Common Report Var(flag_var_tracking_assignments) Init(2) Optimization
2343 Perform variable tracking by annotating assignments
2344
2345 ; Nonzero if we should toggle flag_var_tracking_assignments after
2346 ; processing options and computing its default. */
2347 fvar-tracking-assignments-toggle
2348 Common Report Var(flag_var_tracking_assignments_toggle) Optimization
2349 Toggle -fvar-tracking-assignments
2350
2351 ; Positive if we should track uninitialized variables, negative if
2352 ; we should run the var-tracking pass only to discard debug
2353 ; annotations. When flag_var_tracking_uninit == AUTODETECT_VALUE it
2354 ; will be set according to flag_var_tracking.
2355 fvar-tracking-uninit
2356 Common Report Var(flag_var_tracking_uninit) Optimization
2357 Perform variable tracking and also tag variables that are uninitialized
2358
2359 ftree-vectorize
2360 Common Report Var(flag_tree_vectorize) Optimization
2361 Enable vectorization on trees
2362
2363 ftree-vectorizer-verbose=
2364 Common Joined RejectNegative Ignore
2365 Does nothing. Preserved for backward compatibility.
2366
2367 ftree-loop-vectorize
2368 Common Report Var(flag_tree_loop_vectorize) Optimization
2369 Enable loop vectorization on trees
2370
2371 ftree-slp-vectorize
2372 Common Report Var(flag_tree_slp_vectorize) Optimization
2373 Enable basic block vectorization (SLP) on trees
2374
2375 fvect-cost-model=
2376 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_vect_cost_model) Init(VECT_COST_MODEL_DEFAULT)
2377 Specifies the cost model for vectorization
2378
2379 fsimd-cost-model=
2380 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_simd_cost_model) Init(VECT_COST_MODEL_UNLIMITED)
2381 Specifies the vectorization cost model for code marked with a simd directive
2382
2383 Enum
2384 Name(vect_cost_model) Type(enum vect_cost_model) UnknownError(unknown vectorizer cost model %qs)
2385
2386 EnumValue
2387 Enum(vect_cost_model) String(unlimited) Value(VECT_COST_MODEL_UNLIMITED)
2388
2389 EnumValue
2390 Enum(vect_cost_model) String(dynamic) Value(VECT_COST_MODEL_DYNAMIC)
2391
2392 EnumValue
2393 Enum(vect_cost_model) String(cheap) Value(VECT_COST_MODEL_CHEAP)
2394
2395 fvect-cost-model
2396 Common RejectNegative Alias(fvect-cost-model=,dynamic)
2397 Enables the dynamic vectorizer cost model. Preserved for backward compatibility.
2398
2399 fno-vect-cost-model
2400 Common RejectNegative Alias(fvect-cost-model=,unlimited)
2401 Enables the unlimited vectorizer cost model. Preserved for backward compatibility.
2402
2403 ftree-vect-loop-version
2404 Common Ignore
2405 Does nothing. Preserved for backward compatibility.
2406
2407 ftree-scev-cprop
2408 Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
2409 Enable copy propagation of scalar-evolution information.
2410
2411 ; -fverbose-asm causes extra commentary information to be produced in
2412 ; the generated assembly code (to make it more readable). This option
2413 ; is generally only of use to those who actually need to read the
2414 ; generated assembly code (perhaps while debugging the compiler itself).
2415 ; -fno-verbose-asm, the default, causes the extra information
2416 ; to not be added and is useful when comparing two assembler files.
2417 fverbose-asm
2418 Common Report Var(flag_verbose_asm)
2419 Add extra commentary to assembler output
2420
2421 fvisibility=
2422 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
2423 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility
2424
2425 Enum
2426 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
2427
2428 EnumValue
2429 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
2430
2431 EnumValue
2432 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
2433
2434 EnumValue
2435 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
2436
2437 EnumValue
2438 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
2439
2440 fvtable-verify=
2441 Common Joined RejectNegative Enum(vtv_priority) Var(flag_vtable_verify) Init(VTV_NO_PRIORITY)
2442 Validate vtable pointers before using them.
2443
2444 Enum
2445 Name(vtv_priority) Type(enum vtv_priority) UnknownError(unknown vtable verify initialization priority %qs)
2446
2447 EnumValue
2448 Enum(vtv_priority) String(none) Value(VTV_NO_PRIORITY)
2449
2450 EnumValue
2451 Enum(vtv_priority) String(std) Value(VTV_STANDARD_PRIORITY)
2452
2453 EnumValue
2454 Enum(vtv_priority) String(preinit) Value(VTV_PREINIT_PRIORITY)
2455
2456 fvtv-counts
2457 Common Var(flag_vtv_counts)
2458 Output vtable verification counters.
2459
2460 fvtv-debug
2461 Common Var(flag_vtv_debug)
2462 Output vtable verification pointer sets information.
2463
2464 fvpt
2465 Common Report Var(flag_value_profile_transformations) Optimization
2466 Use expression value profiles in optimizations
2467
2468 fweb
2469 Common Report Var(flag_web) Init(2) Optimization
2470 Construct webs and split unrelated uses of single variable
2471
2472 ftree-builtin-call-dce
2473 Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization
2474 Enable conditional dead code elimination for builtin calls
2475
2476 fwhole-program
2477 Common Report Var(flag_whole_program) Init(0) Optimization
2478 Perform whole program optimizations
2479
2480 fwrapv
2481 Common Report Var(flag_wrapv) Optimization
2482 Assume signed arithmetic overflow wraps around
2483
2484 fzero-initialized-in-bss
2485 Common Report Var(flag_zero_initialized_in_bss) Init(1)
2486 Put zero initialized data in the bss section
2487
2488 g
2489 Common JoinedOrMissing
2490 Generate debug information in default format
2491
2492 gcoff
2493 Common JoinedOrMissing Negative(gdwarf)
2494 Generate debug information in COFF format
2495
2496 gdwarf
2497 Common JoinedOrMissing Negative(gdwarf-)
2498 Generate debug information in default version of DWARF format
2499
2500 gdwarf-
2501 Common Joined UInteger Var(dwarf_version) Init(4) Negative(gstabs)
2502 Generate debug information in DWARF v2 (or later) format
2503
2504 ggdb
2505 Common JoinedOrMissing
2506 Generate debug information in default extended format
2507
2508 gno-pubnames
2509 Common Negative(gpubnames) Var(debug_generate_pub_sections, 0) Init(-1)
2510 Don't generate DWARF pubnames and pubtypes sections.
2511
2512 gpubnames
2513 Common Negative(ggnu-pubnames) Var(debug_generate_pub_sections, 1)
2514 Generate DWARF pubnames and pubtypes sections.
2515
2516 ggnu-pubnames
2517 Common Negative(gno-pubnames) Var(debug_generate_pub_sections, 2)
2518 Generate DWARF pubnames and pubtypes sections with GNU extensions.
2519
2520 gno-record-gcc-switches
2521 Common RejectNegative Var(dwarf_record_gcc_switches,0) Init(1)
2522 Don't record gcc command line switches in DWARF DW_AT_producer.
2523
2524 grecord-gcc-switches
2525 Common RejectNegative Var(dwarf_record_gcc_switches,1)
2526 Record gcc command line switches in DWARF DW_AT_producer.
2527
2528 gno-split-dwarf
2529 Common Driver RejectNegative Var(dwarf_split_debug_info,0) Init(0)
2530 Don't generate debug information in separate .dwo files
2531
2532 gsplit-dwarf
2533 Common Driver RejectNegative Var(dwarf_split_debug_info,1)
2534 Generate debug information in separate .dwo files
2535
2536 gstabs
2537 Common JoinedOrMissing Negative(gstabs+)
2538 Generate debug information in STABS format
2539
2540 gstabs+
2541 Common JoinedOrMissing Negative(gvms)
2542 Generate debug information in extended STABS format
2543
2544 gno-strict-dwarf
2545 Common RejectNegative Var(dwarf_strict,0) Init(0)
2546 Emit DWARF additions beyond selected version
2547
2548 gstrict-dwarf
2549 Common Report RejectNegative Var(dwarf_strict,1)
2550 Don't emit DWARF additions beyond selected version
2551
2552 gtoggle
2553 Common Report Var(flag_gtoggle)
2554 Toggle debug information generation
2555
2556 gvms
2557 Common JoinedOrMissing Negative(gxcoff)
2558 Generate debug information in VMS format
2559
2560 gxcoff
2561 Common JoinedOrMissing Negative(gxcoff+)
2562 Generate debug information in XCOFF format
2563
2564 gxcoff+
2565 Common JoinedOrMissing Negative(gcoff)
2566 Generate debug information in extended XCOFF format
2567
2568 Enum
2569 Name(compressed_debug_sections) Type(int)
2570
2571 ; Since -gz= is completely handled in specs, the values aren't used and we
2572 ; assign arbitrary constants.
2573 EnumValue
2574 Enum(compressed_debug_sections) String(none) Value(0)
2575
2576 EnumValue
2577 Enum(compressed_debug_sections) String(zlib) Value(1)
2578
2579 EnumValue
2580 Enum(compressed_debug_sections) String(zlib-gnu) Value(2)
2581
2582 gz
2583 Common Driver
2584 Generate compressed debug sections
2585
2586 gz=
2587 Common Driver Joined Enum(compressed_debug_sections)
2588 -gz=<format> Generate compressed debug sections in format <format>
2589
2590 h
2591 Driver Joined Separate
2592
2593 iplugindir=
2594 Common Joined Var(plugindir_string) Init(0)
2595 -iplugindir=<dir> Set <dir> to be the default plugin directory
2596
2597 imultiarch
2598 Common Joined Separate RejectDriver Var(imultiarch) Init(0)
2599 -imultiarch <dir> Set <dir> to be the multiarch include subdirectory
2600
2601 l
2602 Driver Joined Separate
2603
2604 n
2605 Driver
2606
2607 no-canonical-prefixes
2608 Driver
2609
2610 nodefaultlibs
2611 Driver
2612
2613 nostartfiles
2614 Driver
2615
2616 nostdlib
2617 Driver
2618
2619 o
2620 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
2621 -o <file> Place output into <file>
2622
2623 p
2624 Common Var(profile_flag)
2625 Enable function profiling
2626
2627 pass-exit-codes
2628 Driver Var(pass_exit_codes)
2629
2630 pedantic
2631 Common Alias(Wpedantic)
2632
2633 pedantic-errors
2634 Common Var(flag_pedantic_errors)
2635 Like -pedantic but issue them as errors
2636
2637 pg
2638 Driver
2639
2640 pipe
2641 Driver Var(use_pipes)
2642
2643 print-file-name=
2644 Driver JoinedOrMissing Var(print_file_name)
2645
2646 print-libgcc-file-name
2647 Driver
2648
2649 print-multi-directory
2650 Driver Var(print_multi_directory)
2651
2652 print-multi-lib
2653 Driver Var(print_multi_lib)
2654
2655 print-multi-os-directory
2656 Driver Var(print_multi_os_directory)
2657
2658 print-multiarch
2659 Driver Var(print_multiarch)
2660
2661 print-prog-name=
2662 Driver JoinedOrMissing Var(print_prog_name)
2663
2664 print-search-dirs
2665 Driver Var(print_search_dirs)
2666
2667 print-sysroot
2668 Driver Var(print_sysroot)
2669
2670 print-sysroot-headers-suffix
2671 Driver Var(print_sysroot_headers_suffix)
2672
2673 quiet
2674 Common Var(quiet_flag) RejectDriver
2675 Do not display functions compiled or elapsed time
2676
2677 r
2678 Driver
2679
2680 s
2681 Driver
2682
2683 save-temps
2684 Driver
2685
2686 save-temps=
2687 Driver Joined
2688
2689 t
2690 Driver
2691
2692 time
2693 Driver Var(report_times)
2694
2695 time=
2696 Driver JoinedOrMissing
2697
2698 u
2699 Driver Joined Separate
2700
2701 undef
2702 Driver
2703 ; C option, but driver must not handle as "-u ndef".
2704
2705 v
2706 Common Driver Var(verbose_flag)
2707 Enable verbose output
2708
2709 version
2710 Common Var(version_flag) RejectDriver
2711 Display the compiler's version
2712
2713 w
2714 Common Var(inhibit_warnings)
2715 Suppress warnings
2716
2717 wrapper
2718 Driver Separate Var(wrapper_string)
2719
2720 x
2721 Driver Joined Separate
2722
2723 shared
2724 Driver RejectNegative Negative(pie)
2725 Create a shared library
2726
2727 shared-libgcc
2728 Driver
2729
2730 specs
2731 Driver Separate Alias(specs=)
2732
2733 specs=
2734 Driver Joined
2735
2736 static
2737 Driver
2738
2739 static-libgcc
2740 Driver
2741
2742 static-libgfortran
2743 Driver
2744 ; Documented for Fortran, but always accepted by driver.
2745
2746 static-libstdc++
2747 Driver
2748
2749 static-libgo
2750 Driver
2751 ; Documented for Go, but always accepted by driver.
2752
2753 static-libasan
2754 Driver
2755
2756 static-libtsan
2757 Driver
2758
2759 static-liblsan
2760 Driver
2761
2762 static-libubsan
2763 Driver
2764
2765 symbolic
2766 Driver
2767
2768 pie
2769 Driver RejectNegative Negative(shared)
2770 Create a position independent executable
2771
2772 z
2773 Driver Joined Separate
2774
2775 fuse-caller-save
2776 Common Report Var(flag_use_caller_save) Optimization
2777 Use caller save register across calls if possible
2778
2779 ; This comment is to ensure we retain the blank line above.