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1 ; Options for the language- and target-independent parts of the compiler.
2
3 ; Copyright (C) 2003-2018 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 ; This variable is set to non-0 only by LTO front-end. 1 indicates that
50 ; the output produced will be used for incrmeental linking (thus weak symbols
51 ; can still be bound).
52 Variable
53 int flag_incremental_link = 0
54
55 ; 0 means straightforward implementation of complex divide acceptable.
56 ; 1 means wide ranges of inputs must work for complex divide.
57 ; 2 means C99-like requirements for complex multiply and divide.
58 Variable
59 int flag_complex_method = 1
60
61 ; Language specific warning pass for unused results.
62 Variable
63 bool flag_warn_unused_result = false
64
65 Variable
66 int *param_values
67
68 ; Nonzero if we should write GIMPLE bytecode for link-time optimization.
69 Variable
70 int flag_generate_lto
71
72 ; Nonzero if we should write GIMPLE bytecode for offload compilation.
73 Variable
74 int flag_generate_offload = 0
75
76 ; True to warn about any objects definitions whose size is larger
77 ; than N bytes. Also want about function definitions whose returned
78 ; values are larger than N bytes, where N is 'larger_than_size'.
79 Variable
80 bool warn_larger_than
81
82 Variable
83 HOST_WIDE_INT larger_than_size
84
85 ; True to warn about any function whose frame size is larger
86 ; than N bytes.
87 Variable
88 bool warn_frame_larger_than
89
90 Variable
91 HOST_WIDE_INT frame_larger_than_size
92
93 ; Nonzero means we should be saving declaration info into a .X file.
94 Variable
95 int flag_gen_aux_info = 0
96
97 ; Nonzero if we are compiling code for a shared library, zero for
98 ; executable.
99 Variable
100 int flag_shlib
101
102 ; These two are really VEC(char_p,heap) *.
103
104 Variable
105 void *flag_instrument_functions_exclude_functions
106
107 Variable
108 void *flag_instrument_functions_exclude_files
109
110 ; Generic structs (e.g. templates not explicitly specialized)
111 ; may not have a compilation unit associated with them, and so
112 ; may need to be treated differently from ordinary structs.
113 ;
114 ; Structs only handled by reference (indirectly), will also usually
115 ; not need as much debugging information.
116
117 Variable
118 enum debug_struct_file debug_struct_ordinary[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
119
120 Variable
121 enum debug_struct_file debug_struct_generic[DINFO_USAGE_NUM_ENUMS] = { DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY, DINFO_STRUCT_FILE_ANY }
122
123 ; True if we should exit after parsing options.
124 Variable
125 bool exit_after_options
126
127 ; Type(s) of debugging information we are producing (if any). See
128 ; flag-types.h for the definitions of the different possible types of
129 ; debugging information.
130 Variable
131 enum debug_info_type write_symbols = NO_DEBUG
132
133 ; Level of debugging information we are producing. See flag-types.h
134 ; for the definitions of the different possible levels.
135 Variable
136 enum debug_info_levels debug_info_level = DINFO_LEVEL_NONE
137
138 ; Nonzero means use GNU-only extensions in the generated symbolic
139 ; debugging information. Currently, this only has an effect when
140 ; write_symbols is set to DBX_DEBUG or XCOFF_DEBUG.
141 Variable
142 bool use_gnu_debug_info_extensions
143
144 ; Original value of maximum field alignment in bytes, specified via
145 ; -fpack-struct=<value>.
146 Variable
147 unsigned int initial_max_fld_align = TARGET_DEFAULT_PACK_STRUCT
148
149 ; Type of stack check.
150 Variable
151 enum stack_check_type flag_stack_check = NO_STACK_CHECK
152
153 ; True if stack usage information needs to be computed.
154 Variable
155 bool flag_stack_usage_info = false
156
157 ; -dA causes debug commentary information to be produced in
158 ; the generated assembly code (to make it more readable). This option
159 ; is generally only of use to those who actually need to read the
160 ; generated assembly code (perhaps while debugging the compiler itself).
161 ; Currently, this switch is only used by dwarf2out.c; however, it is intended
162 ; to be a catchall for printing debug information in the assembler file.
163 Variable
164 int flag_debug_asm
165
166 ; How many NOP insns to place at each function entry by default
167 Variable
168 HOST_WIDE_INT function_entry_patch_area_size
169
170 ; And how far the real asm entry point is into this area
171 Variable
172 HOST_WIDE_INT function_entry_patch_area_start
173
174 ; Balance between GNAT encodings and standard DWARF to emit.
175 Variable
176 enum dwarf_gnat_encodings gnat_encodings = DWARF_GNAT_ENCODINGS_DEFAULT
177
178 ; -dP causes the rtl to be emitted as a comment in assembly.
179 Variable
180 int flag_dump_rtl_in_asm
181
182 ; Whether -da was passed (used only in handle_common_deferred_options).
183 Variable
184 bool flag_dump_all_passed
185
186 ; Other flags saying which kinds of debugging dump have been requested.
187
188 Variable
189 int rtl_dump_and_exit
190
191 Variable
192 int flag_print_asm_name
193
194 ; Name of top-level original source file (what was input to cpp).
195 ; This comes from the #-command at the beginning of the actual input.
196 ; If there isn't any there, then this is the cc1 input file name.
197 Variable
198 const char *main_input_filename
199
200 ; Pointer to base name in main_input_filename, with directories and a
201 ; single final extension removed, and the length of this base
202 ; name.
203
204 Variable
205 const char *main_input_basename
206
207 Variable
208 int main_input_baselength
209
210 ; Which options have been printed by --help.
211 Variable
212 char *help_printed
213
214 ; Which enums have been printed by --help. 0 = not printed, no
215 ; relevant options seen, 1 = relevant option seen, not yet printed, 2
216 ; = printed.
217 Variable
218 char *help_enum_printed
219
220 ; The number of columns for --help output.
221 Variable
222 unsigned int help_columns
223
224 ; Whether this options structure has been through finish_options
225 Variable
226 bool flag_opts_finished
227
228 ; What the sanitizer should instrument
229 Variable
230 unsigned int flag_sanitize
231
232 ; What sanitizers should recover from errors
233 Variable
234 unsigned int flag_sanitize_recover = (SANITIZE_UNDEFINED | SANITIZE_UNDEFINED_NONDEFAULT | SANITIZE_KERNEL_ADDRESS) & ~(SANITIZE_UNREACHABLE | SANITIZE_RETURN)
235
236 ; What the coverage sanitizers should instrument
237 Variable
238 unsigned int flag_sanitize_coverage
239
240 ; Flag whether a prefix has been added to dump_base_name
241 Variable
242 bool dump_base_name_prefixed = false
243
244 ; Flag whether HSA generation has been explicitely disabled
245 Variable
246 bool flag_disable_hsa = false
247
248 ###
249 Driver
250
251 -assemble
252 Driver Alias(S)
253
254 -compile
255 Driver Alias(c)
256
257 -coverage
258 Driver Alias(coverage)
259
260 -debug
261 Common Alias(g)
262
263 -dump
264 Common Separate Alias(d)
265
266 -dump=
267 Common Joined Alias(d)
268
269 -dumpbase
270 Common Separate Alias(dumpbase)
271
272 -dumpdir
273 Common Separate Alias(dumpdir)
274
275 -entry
276 Driver Separate Alias(e)
277
278 -entry=
279 Driver Joined Alias(e)
280
281 -extra-warnings
282 Common Warning Alias(Wextra)
283
284 -for-assembler
285 Driver Separate Alias(Xassembler)
286
287 -for-assembler=
288 Driver JoinedOrMissing Alias(Xassembler)
289
290 -for-linker
291 Driver Separate Alias(Xlinker)
292
293 -for-linker=
294 Driver JoinedOrMissing Alias(Xlinker)
295
296 -force-link
297 Driver Separate Alias(u)
298
299 -force-link=
300 Driver Joined Alias(u)
301
302 -help
303 Common Driver Var(help_flag)
304 Display this information.
305
306 -help=
307 Common Driver Report Joined
308 --help=<class> Display descriptions of a specific class of options. <class> is one or more of optimizers, target, warnings, undocumented, params.
309
310 -language
311 Driver Separate Alias(x)
312
313 -language=
314 Driver Joined Alias(x)
315
316 -library-directory
317 Driver Separate Alias(L)
318
319 -library-directory=
320 Driver Joined Alias(L)
321
322 -no-canonical-prefixes
323 Driver Alias(no-canonical-prefixes)
324
325 -no-standard-libraries
326 Driver Alias(nostdlib)
327
328 -no-sysroot-suffix
329 Driver Var(no_sysroot_suffix)
330
331 -no-warnings
332 Common Alias(w)
333
334 -optimize
335 Common Alias(O)
336
337 -output
338 Common Driver Separate Alias(o) MissingArgError(missing filename after %qs)
339
340 -output=
341 Common Driver Joined Alias(o) MissingArgError(missing filename after %qs)
342
343 -pass-exit-codes
344 Driver Alias(pass-exit-codes)
345
346 -pedantic
347 Common Alias(Wpedantic)
348
349 -pedantic-errors
350 Common Alias(pedantic-errors)
351
352 -pie
353 Driver Alias(pie)
354
355 -static-pie
356 Driver Alias(static-pie)
357
358 -pipe
359 Driver Alias(pipe)
360
361 -prefix
362 Driver Separate Alias(B)
363
364 -prefix=
365 Driver JoinedOrMissing Alias(B)
366
367 -preprocess
368 Driver Alias(E)
369
370 -print-file-name
371 Driver Separate Alias(print-file-name=)
372
373 -print-file-name=
374 Driver JoinedOrMissing Alias(print-file-name=)
375
376 -print-libgcc-file-name
377 Driver Alias(print-libgcc-file-name)
378
379 -print-multi-directory
380 Driver Alias(print-multi-directory)
381
382 -print-multi-lib
383 Driver Alias(print-multi-lib)
384
385 -print-multi-os-directory
386 Driver Alias(print-multi-os-directory)
387
388 -print-multiarch
389 Driver Alias(print-multiarch)
390
391 -print-prog-name
392 Driver Separate Alias(print-prog-name=)
393
394 -print-prog-name=
395 Driver JoinedOrMissing Alias(print-prog-name=)
396
397 -print-search-dirs
398 Driver Alias(print-search-dirs)
399
400 -print-sysroot
401 Driver Alias(print-sysroot)
402
403 -print-sysroot-headers-suffix
404 Driver Alias(print-sysroot-headers-suffix)
405
406 -profile
407 Common Alias(p)
408
409 -save-temps
410 Driver Alias(save-temps)
411
412 -shared
413 Driver Alias(shared)
414
415 -specs
416 Driver Separate Alias(specs=)
417
418 -specs=
419 Driver Joined Alias(specs=)
420
421 -static
422 Driver Alias(static)
423
424 -symbolic
425 Driver Alias(symbolic)
426
427 -target-help
428 Common Driver
429 Alias for --help=target.
430
431 -time
432 Driver Alias(time)
433
434 -verbose
435 Driver Alias(v)
436
437 ;; The driver used to convert options such as --help into forms such
438 ;; as -fhelp; the following four entries are for compatibility with
439 ;; any direct uses of those (undocumented) -f forms
440 fhelp
441 Common Driver Alias(-help)
442
443 fhelp=
444 Common Driver Joined Alias(-help=)
445
446 ftarget-help
447 Common Driver Alias(-target-help)
448
449 fversion
450 Common Driver Alias(-version)
451
452 -param
453 Common Separate
454 --param <param>=<value> Set parameter <param> to value. See below for a complete list of parameters.
455
456 -param=
457 Common Joined Alias(-param)
458
459 -sysroot
460 Driver Separate Alias(-sysroot=)
461
462 -sysroot=
463 Driver JoinedOrMissing
464
465 -version
466 Common Driver
467
468 B
469 Driver Joined Separate
470
471 E
472 Driver
473
474 L
475 Driver Joined Separate
476
477 N
478 Driver
479
480 O
481 Common JoinedOrMissing Optimization
482 -O<number> Set optimization level to <number>.
483
484 Os
485 Common Optimization
486 Optimize for space rather than speed.
487
488 Ofast
489 Common Optimization
490 Optimize for speed disregarding exact standards compliance.
491
492 Og
493 Common Optimization
494 Optimize for debugging experience rather than speed or size.
495
496 Q
497 Driver
498
499 Qn
500 Driver Negative(Qy)
501
502 Qy
503 Driver Negative(Qn)
504
505 R
506 Driver Joined Separate
507
508 S
509 Driver
510
511 T
512 Driver Joined Separate
513
514 Tbss
515 Driver Separate
516
517 Tbss=
518 Driver Joined
519
520 Tdata
521 Driver Separate
522
523 Tdata=
524 Driver Joined
525
526 Ttext
527 Driver Separate
528
529 Ttext=
530 Driver Joined
531
532 W
533 Common RejectNegative Warning Alias(Wextra)
534 This switch is deprecated; use -Wextra instead.
535
536 Wa,
537 Driver JoinedOrMissing RejectNegative
538
539 Wl,
540 Driver JoinedOrMissing RejectNegative
541
542 Wp,
543 Driver JoinedOrMissing RejectNegative
544
545 Waggregate-return
546 Common Var(warn_aggregate_return) Warning
547 Warn about returning structures, unions or arrays.
548
549 Waggressive-loop-optimizations
550 Common Var(warn_aggressive_loop_optimizations) Init(1) Warning
551 Warn if a loop with constant number of iterations triggers undefined behavior.
552
553 Warray-bounds
554 Common Var(warn_array_bounds) Warning
555 Warn if an array is accessed out of bounds.
556
557 Warray-bounds=
558 Common Joined RejectNegative UInteger Var(warn_array_bounds) Warning IntegerRange(0, 2)
559 Warn if an array is accessed out of bounds.
560
561 Wattributes
562 Common Var(warn_attributes) Init(1) Warning
563 Warn about inappropriate attribute usage.
564
565 Wattribute-alias
566 Common Var(warn_attributes) Init(1) Warning
567 Warn about type safety and similar errors in attribute alias and related.
568
569 Wcast-align
570 Common Var(warn_cast_align) Warning
571 Warn about pointer casts which increase alignment.
572
573 Wcast-align=strict
574 Common Var(warn_cast_align,2) Warning
575 Warn about pointer casts which increase alignment.
576
577 Wcpp
578 Common Var(warn_cpp) Init(1) Warning
579 Warn when a #warning directive is encountered.
580
581 Wdeprecated-declarations
582 Common Var(warn_deprecated_decl) Init(1) Warning
583 Warn about uses of __attribute__((deprecated)) declarations.
584
585 Wdisabled-optimization
586 Common Var(warn_disabled_optimization) Warning
587 Warn when an optimization pass is disabled.
588
589 Werror
590 Common Var(warnings_are_errors)
591 Treat all warnings as errors.
592
593 Werror=
594 Common Joined
595 Treat specified warning as error.
596
597 Wextra
598 Common Var(extra_warnings) Warning
599 Print extra (possibly unwanted) warnings.
600
601 Wfatal-errors
602 Common Var(flag_fatal_errors)
603 Exit on the first error occurred.
604
605 Wframe-larger-than=
606 Common RejectNegative Joined UInteger Warning
607 -Wframe-larger-than=<number> Warn if a function's stack frame requires more than <number> bytes.
608
609 Wfree-nonheap-object
610 Common Var(warn_free_nonheap_object) Init(1) Warning
611 Warn when attempting to free a non-heap object.
612
613 Whsa
614 Common Var(warn_hsa) Init(1) Warning
615 Warn when a function cannot be expanded to HSAIL.
616
617 Wimplicit-fallthrough
618 Common Alias(Wimplicit-fallthrough=,3,0) Warning
619
620 Wimplicit-fallthrough=
621 Common Var(warn_implicit_fallthrough) RejectNegative Joined UInteger Warning IntegerRange(0, 5)
622 Warn when a switch case falls through.
623
624 Winline
625 Common Var(warn_inline) Warning
626 Warn when an inlined function cannot be inlined.
627
628 Winvalid-memory-model
629 Common Var(warn_invalid_memory_model) Init(1) Warning
630 Warn when an atomic memory model parameter is known to be outside the valid range.
631
632 Wlarger-than-
633 Common RejectNegative Joined Warning Undocumented Alias(Wlarger-than=)
634
635 Wlarger-than=
636 Common RejectNegative Joined UInteger Warning
637 -Wlarger-than=<number> Warn if an object is larger than <number> bytes.
638
639 Wnonnull-compare
640 Var(warn_nonnull_compare) Warning
641 Warn if comparing pointer parameter with nonnull attribute with NULL.
642
643 Wnull-dereference
644 Common Var(warn_null_dereference) Warning
645 Warn if dereferencing a NULL pointer may lead to erroneous or undefined behavior.
646
647 Wunsafe-loop-optimizations
648 Common Var(warn_unsafe_loop_optimizations) Warning
649 Warn if the loop cannot be optimized due to nontrivial assumptions.
650
651 Wmissing-noreturn
652 Common Warning Alias(Wsuggest-attribute=noreturn)
653
654 Wodr
655 Common Var(warn_odr_violations) Init(1) Warning
656 Warn about some C++ One Definition Rule violations during link time optimization.
657
658 Woverflow
659 Common Var(warn_overflow) Init(1) Warning
660 Warn about overflow in arithmetic expressions.
661
662 Wlto-type-mismatch
663 Common Var(warn_lto_type_mismatch) Init(1) Warning
664 During link time optimization warn about mismatched types of global declarations.
665
666 Wpacked
667 Common Var(warn_packed) Warning
668 Warn when the packed attribute has no effect on struct layout.
669
670 Wpadded
671 Common Var(warn_padded) Warning
672 Warn when padding is required to align structure members.
673
674 Wpedantic
675 Common Var(pedantic) Init(0) Warning
676 Issue warnings needed for strict compliance to the standard.
677
678 Wreturn-local-addr
679 Common Var(warn_return_local_addr) Init(1) Warning
680 Warn about returning a pointer/reference to a local or temporary variable.
681
682 Wshadow
683 Common Var(warn_shadow) Warning
684 Warn when one variable shadows another. Same as -Wshadow=global.
685
686 Wshadow=global
687 Common Warning Alias(Wshadow)
688 Warn when one variable shadows another (globally).
689
690 Wshadow=local
691 Common Var(warn_shadow_local) Warning EnabledBy(Wshadow)
692 Warn when one local variable shadows another local variable or parameter.
693
694 Wshadow-local
695 Common Warning Undocumented Alias(Wshadow=local)
696
697 Wshadow=compatible-local
698 Common Var(warn_shadow_compatible_local) Warning EnabledBy(Wshadow=local)
699 Warn when one local variable shadows another local variable or parameter of compatible type.
700
701 Wshadow-compatible-local
702 Common Warning Undocumented Alias(Wshadow=compatible-local)
703
704 Wstack-protector
705 Common Var(warn_stack_protect) Warning
706 Warn when not issuing stack smashing protection for some reason.
707
708 Wstack-usage=
709 Common Joined RejectNegative UInteger Var(warn_stack_usage) Warning
710 -Wstack-usage=<number> Warn if stack usage might be larger than specified amount.
711
712 Wstrict-aliasing
713 Common Warning
714 Warn about code which might break strict aliasing rules.
715
716 Wstrict-aliasing=
717 Common Joined RejectNegative UInteger Var(warn_strict_aliasing) Warning
718 Warn about code which might break strict aliasing rules.
719
720 Wstrict-overflow
721 Common Warning
722 Warn about optimizations that assume that signed overflow is undefined.
723
724 Wstrict-overflow=
725 Common Joined RejectNegative UInteger Var(warn_strict_overflow) Warning
726 Warn about optimizations that assume that signed overflow is undefined.
727
728 Wsuggest-attribute=cold
729 Common Var(warn_suggest_attribute_cold) Warning
730 Warn about functions which might be candidates for __attribute__((cold)).
731
732 Wsuggest-attribute=const
733 Common Var(warn_suggest_attribute_const) Warning
734 Warn about functions which might be candidates for __attribute__((const)).
735
736 Wsuggest-attribute=pure
737 Common Var(warn_suggest_attribute_pure) Warning
738 Warn about functions which might be candidates for __attribute__((pure)).
739
740 Wsuggest-attribute=noreturn
741 Common Var(warn_suggest_attribute_noreturn) Warning
742 Warn about functions which might be candidates for __attribute__((noreturn)).
743
744 Wsuggest-attribute=malloc
745 Common Var(warn_suggest_attribute_malloc) Warning
746 Warn about functions which might be candidates for __attribute__((malloc)).
747
748 Wsuggest-final-types
749 Common Var(warn_suggest_final_types) Warning
750 Warn about C++ polymorphic types where adding final keyword would improve code quality.
751
752 Wsuggest-final-methods
753 Common Var(warn_suggest_final_methods) Warning
754 Warn about C++ virtual methods where adding final keyword would improve code quality.
755
756 Wswitch-unreachable
757 Common Var(warn_switch_unreachable) Warning Init(1)
758 Warn about statements between switch's controlling expression and the first
759 case.
760
761 Wsystem-headers
762 Common Var(warn_system_headers) Warning
763 Do not suppress warnings from system headers.
764
765 Wtrampolines
766 Common Var(warn_trampolines) Warning
767 Warn whenever a trampoline is generated.
768
769 Wtype-limits
770 Common Var(warn_type_limits) Warning EnabledBy(Wextra)
771 Warn if a comparison is always true or always false due to the limited range of the data type.
772
773 Wuninitialized
774 Common Var(warn_uninitialized) Warning EnabledBy(Wextra)
775 Warn about uninitialized automatic variables.
776
777 Wmaybe-uninitialized
778 Common Var(warn_maybe_uninitialized) Warning EnabledBy(Wuninitialized)
779 Warn about maybe uninitialized automatic variables.
780
781 Wunreachable-code
782 Common Ignore Warning
783 Does nothing. Preserved for backward compatibility.
784
785 Wunused
786 Common Var(warn_unused) Init(0) Warning
787 Enable all -Wunused- warnings.
788
789 Wunused-but-set-parameter
790 Common Var(warn_unused_but_set_parameter) Warning EnabledBy(Wunused && Wextra)
791 Warn when a function parameter is only set, otherwise unused.
792
793 Wunused-but-set-variable
794 Common Var(warn_unused_but_set_variable) Warning EnabledBy(Wunused)
795 Warn when a variable is only set, otherwise unused.
796
797 Wunused-function
798 Common Var(warn_unused_function) Warning EnabledBy(Wunused)
799 Warn when a function is unused.
800
801 Wunused-label
802 Common Var(warn_unused_label) Warning EnabledBy(Wunused)
803 Warn when a label is unused.
804
805 Wunused-parameter
806 Common Var(warn_unused_parameter) Warning EnabledBy(Wunused && Wextra)
807 Warn when a function parameter is unused.
808
809 Wunused-value
810 Common Var(warn_unused_value) Warning EnabledBy(Wunused)
811 Warn when an expression value is unused.
812
813 Wunused-variable
814 Common Var(warn_unused_variable) Warning EnabledBy(Wunused)
815 Warn when a variable is unused.
816
817 Wcoverage-mismatch
818 Common Var(warn_coverage_mismatch) Init(1) Warning
819 Warn in case profiles in -fprofile-use do not match.
820
821 Wvector-operation-performance
822 Common Var(warn_vector_operation_performance) Warning
823 Warn when a vector operation is compiled outside the SIMD.
824
825 Xassembler
826 Driver Separate
827
828 Xlinker
829 Driver Separate
830
831 Xpreprocessor
832 Driver Separate
833
834 Z
835 Driver
836
837 aux-info
838 Common Separate Var(aux_info_file_name)
839 -aux-info <file> Emit declaration information into <file>.
840
841 aux-info=
842 Common Joined Alias(aux-info)
843
844 auxbase
845 Common Separate RejectDriver Var(aux_base_name)
846
847 auxbase-strip
848 Common Separate RejectDriver
849
850 coverage
851 Driver
852
853 c
854 Driver
855
856 d
857 Common Joined
858 -d<letters> Enable dumps from specific passes of the compiler.
859
860 dumpbase
861 Common Separate Var(dump_base_name)
862 -dumpbase <file> Set the file basename to be used for dumps.
863
864 dumpdir
865 Common Separate Var(dump_dir_name)
866 -dumpdir <dir> Set the directory name to be used for dumps.
867
868 dumpmachine
869 Driver
870
871 dumpspecs
872 Driver
873
874 dumpversion
875 Driver
876
877 dumpfullversion
878 Driver
879
880 e
881 Driver Joined Separate
882
883 ; This option has historically been passed down to the linker by an
884 ; accident of a %{e*} spec, so ensure it continues to be passed down
885 ; as a single option. The supported option for this purpose is
886 ; -rdynamic. See PR 47390.
887 export-dynamic
888 Driver Undocumented
889
890 ; The version of the C++ ABI in use. The following values are allowed:
891 ;
892 ; 0: The version of the ABI believed most conformant with the C++ ABI
893 ; specification. This ABI may change as bugs are discovered and fixed.
894 ; Therefore, 0 will not necessarily indicate the same ABI in different
895 ; versions of G++.
896 ;
897 ; 1: The version of the ABI first used in G++ 3.2. No longer selectable.
898 ;
899 ; 2: The version of the ABI first used in G++ 3.4, and the default
900 ; until GCC 4.9.
901 ;
902 ; 3: The version of the ABI that fixes the missing underscore
903 ; in template non-type arguments of pointer type.
904 ;
905 ; 4: The version of the ABI that introduces unambiguous mangling of
906 ; vector types. First selectable in G++ 4.5.
907 ;
908 ; 5: The version of the ABI that ignores attribute const/noreturn
909 ; in function pointer mangling, and corrects mangling of decltype and
910 ; function parameters used in other parameters and the return type.
911 ; First selectable in G++ 4.6.
912 ;
913 ; 6: The version of the ABI that doesn't promote scoped enums to int and
914 ; changes the mangling of template argument packs, const/static_cast,
915 ; prefix ++ and --, and a class scope function used as a template
916 ; argument.
917 ; First selectable in G++ 4.7.
918 ;
919 ; 7: The version of the ABI that treats nullptr_t as a builtin type and
920 ; corrects the mangling of lambdas in default argument scope.
921 ; First selectable in G++ 4.8.
922 ;
923 ; 8: The version of the ABI that corrects the substitution behavior of
924 ; function types with function-cv-qualifiers.
925 ; First selectable in G++ 4.9 and default in G++ 5.
926 ;
927 ; 9: The version of the ABI that corrects the alignment of nullptr_t.
928 ; First selectable and default in G++ 5.2.
929 ;
930 ; 10: The version of the ABI that mangles attributes that affect type
931 ; identity, such as ia32 calling convention attributes (stdcall, etc.)
932 ; Default in G++ 6 (set in c_common_post_options).
933 ;
934 ; 11: The version of the ABI that corrects mangling of sizeof... expressions
935 ; and introduces new inheriting constructor handling.
936 ; Default in G++ 7.
937 ;
938 ; 12: Corrects the calling convention for classes with only deleted copy/move
939 ; constructors and changes passing/returning of empty records.
940 ; Default in G++ 8.
941 ;
942 ; Additional positive integers will be assigned as new versions of
943 ; the ABI become the default version of the ABI.
944 fabi-version=
945 Common Joined RejectNegative UInteger Var(flag_abi_version) Init(0)
946 The version of the C++ ABI in use.
947
948 faggressive-loop-optimizations
949 Common Report Var(flag_aggressive_loop_optimizations) Optimization Init(1)
950 Aggressively optimize loops using language constraints.
951
952 falign-functions
953 Common Report Var(align_functions,0) Optimization UInteger
954 Align the start of functions.
955
956 falign-functions=
957 Common RejectNegative Joined UInteger Var(align_functions)
958
959 flimit-function-alignment
960 Common Report Var(flag_limit_function_alignment) Optimization Init(0)
961
962 falign-jumps
963 Common Report Var(align_jumps,0) Optimization UInteger
964 Align labels which are only reached by jumping.
965
966 falign-jumps=
967 Common RejectNegative Joined UInteger Var(align_jumps)
968
969 falign-labels
970 Common Report Var(align_labels,0) Optimization UInteger
971 Align all labels.
972
973 falign-labels=
974 Common RejectNegative Joined UInteger Var(align_labels)
975
976 falign-loops
977 Common Report Var(align_loops,0) Optimization UInteger
978 Align the start of loops.
979
980 falign-loops=
981 Common RejectNegative Joined UInteger Var(align_loops)
982
983 fargument-alias
984 Common Ignore
985 Does nothing. Preserved for backward compatibility.
986
987 fargument-noalias
988 Common Ignore
989 Does nothing. Preserved for backward compatibility.
990
991 fargument-noalias-global
992 Common Ignore
993 Does nothing. Preserved for backward compatibility.
994
995 fargument-noalias-anything
996 Common Ignore
997 Does nothing. Preserved for backward compatibility.
998
999 fsanitize=
1000 Common Driver Report Joined
1001 Select what to sanitize.
1002
1003 fsanitize-coverage=
1004 Common Report Joined
1005 Select what to coverage sanitize.
1006
1007 fasan-shadow-offset=
1008 Common Joined RejectNegative Var(common_deferred_options) Defer
1009 -fasan-shadow-offset=<number> Use custom shadow memory offset.
1010
1011 fsanitize-sections=
1012 Common Joined RejectNegative Var(common_deferred_options) Defer
1013 -fsanitize-sections=<sec1,sec2,...> Sanitize global variables
1014 in user-defined sections.
1015
1016 fsanitize-recover=
1017 Common Report Joined
1018 After diagnosing undefined behavior attempt to continue execution.
1019
1020 fsanitize-recover
1021 Common Report
1022 This switch is deprecated; use -fsanitize-recover= instead.
1023
1024 fsanitize-address-use-after-scope
1025 Common Driver Report Var(flag_sanitize_address_use_after_scope) Init(0)
1026
1027 fsanitize-undefined-trap-on-error
1028 Common Driver Report Var(flag_sanitize_undefined_trap_on_error) Init(0)
1029 Use trap instead of a library function for undefined behavior sanitization.
1030
1031 fasynchronous-unwind-tables
1032 Common Report Var(flag_asynchronous_unwind_tables) Optimization
1033 Generate unwind tables that are exact at each instruction boundary.
1034
1035 fauto-inc-dec
1036 Common Report Var(flag_auto_inc_dec) Init(1) Optimization
1037 Generate auto-inc/dec instructions.
1038
1039 fauto-profile
1040 Common Report Var(flag_auto_profile)
1041 Use sample profile information for call graph node weights. The default
1042 profile file is fbdata.afdo in 'pwd'.
1043
1044 fauto-profile=
1045 Common Joined RejectNegative Var(auto_profile_file)
1046 Use sample profile information for call graph node weights. The profile
1047 file is specified in the argument.
1048
1049 ; -fcheck-bounds causes gcc to generate array bounds checks.
1050 ; For C, C++ and ObjC: defaults off.
1051 ; For Java: defaults to on.
1052 ; For Fortran: defaults to off.
1053 fbounds-check
1054 Common Report Var(flag_bounds_check)
1055 Generate code to check bounds before indexing arrays.
1056
1057 fbranch-count-reg
1058 Common Report Var(flag_branch_on_count_reg) Optimization
1059 Replace add, compare, branch with branch on count register.
1060
1061 fbranch-probabilities
1062 Common Report Var(flag_branch_probabilities) Optimization
1063 Use profiling information for branch probabilities.
1064
1065 fbranch-target-load-optimize
1066 Common Report Var(flag_branch_target_load_optimize) Optimization
1067 Perform branch target load optimization before prologue / epilogue threading.
1068
1069 fbranch-target-load-optimize2
1070 Common Report Var(flag_branch_target_load_optimize2) Optimization
1071 Perform branch target load optimization after prologue / epilogue threading.
1072
1073 fbtr-bb-exclusive
1074 Common Report Var(flag_btr_bb_exclusive) Optimization
1075 Restrict target load migration not to re-use registers in any basic block.
1076
1077 fcall-saved-
1078 Common Joined RejectNegative Var(common_deferred_options) Defer
1079 -fcall-saved-<register> Mark <register> as being preserved across functions.
1080
1081 fcall-used-
1082 Common Joined RejectNegative Var(common_deferred_options) Defer
1083 -fcall-used-<register> Mark <register> as being corrupted by function calls.
1084
1085 ; Nonzero for -fcaller-saves: allocate values in regs that need to
1086 ; be saved across function calls, if that produces overall better code.
1087 ; Optional now, so people can test it.
1088 fcaller-saves
1089 Common Report Var(flag_caller_saves) Optimization
1090 Save registers around function calls.
1091
1092 fcheck-data-deps
1093 Common Report Var(flag_check_data_deps)
1094 This switch is deprecated; do not use.
1095
1096 fcheck-new
1097 Common Var(flag_check_new)
1098 Check the return value of new in C++.
1099
1100 fchecking
1101 Common Var(flag_checking) Init(CHECKING_P ? ENABLE_EXTRA_CHECKING ? 2 : 1 : 0)
1102 Perform internal consistency checkings.
1103
1104 fchecking=
1105 Common Joined RejectNegative UInteger Var(flag_checking)
1106 Perform internal consistency checkings.
1107
1108 fcode-hoisting
1109 Common Report Var(flag_code_hoisting) Optimization
1110 Enable code hoisting.
1111
1112 fcombine-stack-adjustments
1113 Common Report Var(flag_combine_stack_adjustments) Optimization
1114 Looks for opportunities to reduce stack adjustments and stack references.
1115
1116 fcommon
1117 Common Report Var(flag_no_common,0)
1118 Do not put uninitialized globals in the common section.
1119
1120 fcompare-debug
1121 Driver
1122 ; Converted by the driver to -fcompare-debug= options.
1123
1124 fcompare-debug=
1125 Common Driver JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
1126 -fcompare-debug[=<opts>] Compile with and without e.g. -gtoggle, and compare the final-insns dump.
1127
1128 fcompare-debug-second
1129 Common Driver RejectNegative Var(flag_compare_debug)
1130 Run only the second compilation of -fcompare-debug.
1131
1132 fcompare-elim
1133 Common Report Var(flag_compare_elim_after_reload) Optimization
1134 Perform comparison elimination after register allocation has finished.
1135
1136 fconserve-stack
1137 Common Var(flag_conserve_stack) Optimization
1138 Do not perform optimizations increasing noticeably stack usage.
1139
1140 fcprop-registers
1141 Common Report Var(flag_cprop_registers) Optimization
1142 Perform a register copy-propagation optimization pass.
1143
1144 fcrossjumping
1145 Common Report Var(flag_crossjumping) Optimization
1146 Perform cross-jumping optimization.
1147
1148 fcse-follow-jumps
1149 Common Report Var(flag_cse_follow_jumps) Optimization
1150 When running CSE, follow jumps to their targets.
1151
1152 fcse-skip-blocks
1153 Common Ignore
1154 Does nothing. Preserved for backward compatibility.
1155
1156 fcx-limited-range
1157 Common Report Var(flag_cx_limited_range) Optimization SetByCombined
1158 Omit range reduction step when performing complex division.
1159
1160 fcx-fortran-rules
1161 Common Report Var(flag_cx_fortran_rules) Optimization
1162 Complex multiplication and division follow Fortran rules.
1163
1164 fdata-sections
1165 Common Report Var(flag_data_sections)
1166 Place data items into their own section.
1167
1168 fdbg-cnt-list
1169 Common Report Var(common_deferred_options) Defer
1170 List all available debugging counters with their limits and counts.
1171
1172 fdbg-cnt=
1173 Common RejectNegative Joined Var(common_deferred_options) Defer
1174 -fdbg-cnt=<counter>:<limit>[,<counter>:<limit>,...] Set the debug counter limit.
1175
1176 fdebug-prefix-map=
1177 Common Joined RejectNegative Var(common_deferred_options) Defer
1178 Map one directory name to another in debug information.
1179
1180 fdebug-types-section
1181 Common Report Var(flag_debug_types_section) Init(0)
1182 Output .debug_types section when using DWARF v4 debuginfo.
1183
1184 ; Nonzero for -fdefer-pop: don't pop args after each function call
1185 ; instead save them up to pop many calls' args with one insns.
1186 fdefer-pop
1187 Common Report Var(flag_defer_pop) Optimization
1188 Defer popping functions args from stack until later.
1189
1190 fdelayed-branch
1191 Common Report Var(flag_delayed_branch) Optimization
1192 Attempt to fill delay slots of branch instructions.
1193
1194 fdelete-dead-exceptions
1195 Common Report Var(flag_delete_dead_exceptions) Init(0) Optimization
1196 Delete dead instructions that may throw exceptions.
1197
1198 fdelete-null-pointer-checks
1199 Common Report Var(flag_delete_null_pointer_checks) Init(-1) Optimization
1200 Delete useless null pointer checks.
1201
1202 fdevirtualize-at-ltrans
1203 Common Report Var(flag_ltrans_devirtualize)
1204 Stream extra data to support more aggressive devirtualization in LTO local transformation mode.
1205
1206 fdevirtualize-speculatively
1207 Common Report Var(flag_devirtualize_speculatively) Optimization
1208 Perform speculative devirtualization.
1209
1210 fdevirtualize
1211 Common Report Var(flag_devirtualize) Optimization
1212 Try to convert virtual calls to direct ones.
1213
1214 fdiagnostics-show-location=
1215 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
1216 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics.
1217
1218 ; Required for these enum values.
1219 SourceInclude
1220 pretty-print.h
1221
1222 Enum
1223 Name(diagnostic_prefixing_rule) Type(int)
1224
1225 EnumValue
1226 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1227
1228 EnumValue
1229 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1230
1231 fdiagnostics-show-caret
1232 Common Var(flag_diagnostics_show_caret) Init(1)
1233 Show the source line with a caret indicating the column.
1234
1235 fdiagnostics-color
1236 Common Alias(fdiagnostics-color=,always,never)
1237 ;
1238
1239 fdiagnostics-color=
1240 Driver Common Joined RejectNegative Var(flag_diagnostics_show_color) Enum(diagnostic_color_rule) Init(DIAGNOSTICS_COLOR_NO)
1241 -fdiagnostics-color=[never|always|auto] Colorize diagnostics.
1242
1243 ; Required for these enum values.
1244 SourceInclude
1245 diagnostic-color.h
1246
1247 Enum
1248 Name(diagnostic_color_rule) Type(int)
1249
1250 EnumValue
1251 Enum(diagnostic_color_rule) String(never) Value(DIAGNOSTICS_COLOR_NO)
1252
1253 EnumValue
1254 Enum(diagnostic_color_rule) String(always) Value(DIAGNOSTICS_COLOR_YES)
1255
1256 EnumValue
1257 Enum(diagnostic_color_rule) String(auto) Value(DIAGNOSTICS_COLOR_AUTO)
1258
1259 fdiagnostics-parseable-fixits
1260 Common Var(flag_diagnostics_parseable_fixits)
1261 Print fix-it hints in machine-readable form.
1262
1263 fdiagnostics-generate-patch
1264 Common Var(flag_diagnostics_generate_patch)
1265 Print fix-it hints to stderr in unified diff format.
1266
1267 fdiagnostics-show-option
1268 Common Var(flag_diagnostics_show_option) Init(1)
1269 Amend appropriate diagnostic messages with the command line option that controls them.
1270
1271 fdisable-
1272 Common Joined RejectNegative Var(common_deferred_options) Defer
1273 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 disables an optimization pass.
1274
1275 fenable-
1276 Common Joined RejectNegative Var(common_deferred_options) Defer
1277 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 enables an optimization pass.
1278
1279 fdump-
1280 Common Joined RejectNegative Var(common_deferred_options) Defer
1281 -fdump-<type> Dump various compiler internals to a file.
1282
1283 fdump-final-insns
1284 Driver RejectNegative
1285
1286 fdump-final-insns=
1287 Common RejectNegative Joined Var(flag_dump_final_insns)
1288 -fdump-final-insns=filename Dump to filename the insns at the end of translation.
1289
1290 fdump-go-spec=
1291 Common RejectNegative Joined Var(flag_dump_go_spec)
1292 -fdump-go-spec=filename Write all declarations to file as Go code.
1293
1294 fdump-noaddr
1295 Common Report Var(flag_dump_noaddr)
1296 Suppress output of addresses in debugging dumps.
1297
1298 freport-bug
1299 Common Driver Var(flag_report_bug)
1300 Collect and dump debug information into temporary file if ICE in C/C++
1301 compiler occurred.
1302
1303 fdump-internal-locations
1304 Common Var(flag_dump_locations) Init(0)
1305 Dump detailed information on GCC's internal representation of source code locations.
1306
1307 fdump-passes
1308 Common Var(flag_dump_passes) Init(0)
1309 Dump optimization passes.
1310
1311 fdump-unnumbered
1312 Common Report Var(flag_dump_unnumbered)
1313 Suppress output of instruction numbers, line number notes and addresses in debugging dumps.
1314
1315 fdump-unnumbered-links
1316 Common Report Var(flag_dump_unnumbered_links)
1317 Suppress output of previous and next insn numbers in debugging dumps.
1318
1319 fdwarf2-cfi-asm
1320 Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1321 Enable CFI tables via GAS assembler directives.
1322
1323 fearly-inlining
1324 Common Report Var(flag_early_inlining) Init(1) Optimization
1325 Perform early inlining.
1326
1327 feliminate-dwarf2-dups
1328 Common Ignore
1329 Does nothing. Preserved for backward compatibility.
1330
1331 fipa-sra
1332 Common Report Var(flag_ipa_sra) Init(0) Optimization
1333 Perform interprocedural reduction of aggregates.
1334
1335 feliminate-unused-debug-symbols
1336 Common Report Var(flag_debug_only_used_symbols)
1337 Perform unused symbol elimination in debug info.
1338
1339 feliminate-unused-debug-types
1340 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
1341 Perform unused type elimination in debug info.
1342
1343 femit-class-debug-always
1344 Common Report Var(flag_emit_class_debug_always) Init(0)
1345 Do not suppress C++ class debug information.
1346
1347 fexceptions
1348 Common Report Var(flag_exceptions) Optimization
1349 Enable exception handling.
1350
1351 fexpensive-optimizations
1352 Common Report Var(flag_expensive_optimizations) Optimization
1353 Perform a number of minor, expensive optimizations.
1354
1355 fexcess-precision=
1356 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision_cmdline) Init(EXCESS_PRECISION_DEFAULT) SetByCombined
1357 -fexcess-precision=[fast|standard] Specify handling of excess floating-point precision.
1358
1359 Enum
1360 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1361
1362 EnumValue
1363 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1364
1365 EnumValue
1366 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1367
1368 ; Whether we permit the extended set of values for FLT_EVAL_METHOD
1369 ; introduced in ISO/IEC TS 18661-3, or limit ourselves to those in C99/C11.
1370 fpermitted-flt-eval-methods=
1371 Common Joined RejectNegative Enum(permitted_flt_eval_methods) Var(flag_permitted_flt_eval_methods) Init(PERMITTED_FLT_EVAL_METHODS_DEFAULT)
1372 -fpermitted-flt-eval-methods=[c11|ts-18661] Specify which values of FLT_EVAL_METHOD are permitted.
1373
1374 Enum
1375 Name(permitted_flt_eval_methods) Type(enum permitted_flt_eval_methods) UnknownError(unknown specification for the set of FLT_EVAL_METHOD values to permit %qs)
1376
1377 EnumValue
1378 Enum(permitted_flt_eval_methods) String(c11) Value(PERMITTED_FLT_EVAL_METHODS_C11)
1379
1380 EnumValue
1381 Enum(permitted_flt_eval_methods) String(ts-18661-3) Value(PERMITTED_FLT_EVAL_METHODS_TS_18661)
1382
1383 ffast-math
1384 Common Optimization
1385
1386 ffat-lto-objects
1387 Common Var(flag_fat_lto_objects)
1388 Output lto objects containing both the intermediate language and binary output.
1389
1390 ffinite-math-only
1391 Common Report Var(flag_finite_math_only) Optimization SetByCombined
1392 Assume no NaNs or infinities are generated.
1393
1394 ffixed-
1395 Common Joined RejectNegative Var(common_deferred_options) Defer
1396 -ffixed-<register> Mark <register> as being unavailable to the compiler.
1397
1398 ffloat-store
1399 Common Report Var(flag_float_store) Optimization
1400 Don't allocate floats and doubles in extended-precision registers.
1401
1402 fforce-addr
1403 Common Ignore
1404 Does nothing. Preserved for backward compatibility.
1405
1406 fforward-propagate
1407 Common Report Var(flag_forward_propagate) Optimization
1408 Perform a forward propagation pass on RTL.
1409
1410 ffp-contract=
1411 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST) Optimization
1412 -ffp-contract=[off|on|fast] Perform floating-point expression contraction.
1413
1414 Enum
1415 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1416
1417 EnumValue
1418 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1419
1420 ; Not implemented, fall back to conservative FP_CONTRACT_OFF.
1421 EnumValue
1422 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_OFF)
1423
1424 EnumValue
1425 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1426
1427 ffp-int-builtin-inexact
1428 Common Report Var(flag_fp_int_builtin_inexact) Init(1) Optimization
1429 Allow built-in functions ceil, floor, round, trunc to raise \"inexact\" exceptions.
1430
1431 ; Nonzero means don't put addresses of constant functions in registers.
1432 ; Used for compiling the Unix kernel, where strange substitutions are
1433 ; done on the assembly output.
1434 ffunction-cse
1435 Common Report Var(flag_no_function_cse,0) Optimization
1436 Allow function addresses to be held in registers.
1437
1438 ffunction-sections
1439 Common Report Var(flag_function_sections)
1440 Place each function into its own section.
1441
1442 fgcse
1443 Common Report Var(flag_gcse) Optimization
1444 Perform global common subexpression elimination.
1445
1446 fgcse-lm
1447 Common Report Var(flag_gcse_lm) Init(1) Optimization
1448 Perform enhanced load motion during global common subexpression elimination.
1449
1450 fgcse-sm
1451 Common Report Var(flag_gcse_sm) Init(0) Optimization
1452 Perform store motion after global common subexpression elimination.
1453
1454 fgcse-las
1455 Common Report Var(flag_gcse_las) Init(0) Optimization
1456 Perform redundant load after store elimination in global common subexpression
1457 elimination.
1458
1459 fgcse-after-reload
1460 Common Report Var(flag_gcse_after_reload) Optimization
1461 Perform global common subexpression elimination after register allocation has
1462 finished.
1463
1464 Enum
1465 Name(dwarf_gnat_encodings) Type(int)
1466
1467 EnumValue
1468 Enum(dwarf_gnat_encodings) String(all) Value(DWARF_GNAT_ENCODINGS_ALL)
1469
1470 EnumValue
1471 Enum(dwarf_gnat_encodings) String(gdb) Value(DWARF_GNAT_ENCODINGS_GDB)
1472
1473 EnumValue
1474 Enum(dwarf_gnat_encodings) String(minimal) Value(DWARF_GNAT_ENCODINGS_MINIMAL)
1475
1476 fgnat-encodings=
1477 Common Enum(dwarf_gnat_encodings) Joined RejectNegative Report Undocumented Var(gnat_encodings)
1478 -fgnat-encodings=[all|gdb|minimal] Select the balance between GNAT encodings and standard DWARF emitted in the debug information
1479
1480 ; This option is not documented yet as its semantics will change.
1481 fgraphite
1482 Common Report Var(flag_graphite) Optimization
1483 Enable in and out of Graphite representation.
1484
1485 fgraphite-identity
1486 Common Report Var(flag_graphite_identity) Optimization
1487 Enable Graphite Identity transformation.
1488
1489 fhoist-adjacent-loads
1490 Common Report Var(flag_hoist_adjacent_loads) Optimization
1491 Enable hoisting adjacent loads to encourage generating conditional move
1492 instructions.
1493
1494 fkeep-gc-roots-live
1495 Common Undocumented Report Var(flag_keep_gc_roots_live) Optimization
1496 ; Always keep a pointer to a live memory block
1497
1498 floop-parallelize-all
1499 Common Report Var(flag_loop_parallelize_all) Optimization
1500 Mark all loops as parallel.
1501
1502 floop-strip-mine
1503 Common Alias(floop-nest-optimize)
1504 Enable loop nest transforms. Same as -floop-nest-optimize.
1505
1506 floop-interchange
1507 Common Report Var(flag_loop_interchange) Optimization
1508 Enable loop interchange on trees.
1509
1510 floop-block
1511 Common Alias(floop-nest-optimize)
1512 Enable loop nest transforms. Same as -floop-nest-optimize.
1513
1514 floop-unroll-and-jam
1515 Common Report Var(flag_unroll_jam) Optimization
1516 Perform unroll-and-jam on loops.
1517
1518 fgnu-tm
1519 Common Report Var(flag_tm)
1520 Enable support for GNU transactional memory.
1521
1522 fgnu-unique
1523 Common Report Var(flag_gnu_unique) Init(1)
1524 Use STB_GNU_UNIQUE if supported by the assembler.
1525
1526 floop-flatten
1527 Common Ignore
1528 Does nothing. Preserved for backward compatibility.
1529
1530 floop-nest-optimize
1531 Common Report Var(flag_loop_nest_optimize) Optimization
1532 Enable the loop nest optimizer.
1533
1534 fstrict-volatile-bitfields
1535 Common Report Var(flag_strict_volatile_bitfields) Init(-1) Optimization
1536 Force bitfield accesses to match their type width.
1537
1538 fstore-merging
1539 Common Report Var(flag_store_merging) Optimization
1540 Merge adjacent stores.
1541
1542 fguess-branch-probability
1543 Common Report Var(flag_guess_branch_prob) Optimization
1544 Enable guessing of branch probabilities.
1545
1546 ; Nonzero means ignore `#ident' directives. 0 means handle them.
1547 ; Generate position-independent code for executables if possible
1548 ; On SVR4 targets, it also controls whether or not to emit a
1549 ; string identifying the compiler.
1550 fident
1551 Common Report Var(flag_no_ident,0)
1552 Process #ident directives.
1553
1554 fif-conversion
1555 Common Report Var(flag_if_conversion) Optimization
1556 Perform conversion of conditional jumps to branchless equivalents.
1557
1558 fif-conversion2
1559 Common Report Var(flag_if_conversion2) Optimization
1560 Perform conversion of conditional jumps to conditional execution.
1561
1562 fstack-reuse=
1563 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL) Optimization
1564 -fstack-reuse=[all|named_vars|none] Set stack reuse level for local variables.
1565
1566 Enum
1567 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1568
1569 EnumValue
1570 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1571
1572 EnumValue
1573 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1574
1575 EnumValue
1576 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1577
1578 ftree-loop-if-convert
1579 Common Report Var(flag_tree_loop_if_convert) Init(-1) Optimization
1580 Convert conditional jumps in innermost loops to branchless equivalents.
1581
1582 ftree-loop-if-convert-stores
1583 Common Ignore
1584 Does nothing. Preserved for backward compatibility.
1585
1586 ; -finhibit-size-directive inhibits output of .size for ELF.
1587 ; This is used only for compiling crtstuff.c,
1588 ; and it may be extended to other effects
1589 ; needed for crtstuff.c on other systems.
1590 finhibit-size-directive
1591 Common Report Var(flag_inhibit_size_directive)
1592 Do not generate .size directives.
1593
1594 findirect-inlining
1595 Common Report Var(flag_indirect_inlining) Optimization
1596 Perform indirect inlining.
1597
1598 ; General flag to enable inlining. Specifying -fno-inline will disable
1599 ; all inlining apart from always-inline functions.
1600 finline
1601 Common Report Var(flag_no_inline,0) Init(0) Optimization
1602 Enable inlining of function declared \"inline\", disabling disables all inlining.
1603
1604 finline-small-functions
1605 Common Report Var(flag_inline_small_functions) Optimization
1606 Integrate functions into their callers when code size is known not to grow.
1607
1608 finline-functions
1609 Common Report Var(flag_inline_functions) Optimization
1610 Integrate functions not declared \"inline\" into their callers when profitable.
1611
1612 finline-functions-called-once
1613 Common Report Var(flag_inline_functions_called_once) Optimization
1614 Integrate functions only required by their single caller.
1615
1616 finline-limit-
1617 Common RejectNegative Joined Alias(finline-limit=)
1618
1619 finline-limit=
1620 Common RejectNegative Joined UInteger
1621 -finline-limit=<number> Limit the size of inlined functions to <number>.
1622
1623 finline-atomics
1624 Common Report Var(flag_inline_atomics) Init(1) Optimization
1625 Inline __atomic operations when a lock free instruction sequence is available.
1626
1627 fcf-protection
1628 Common RejectNegative Alias(fcf-protection=,full)
1629
1630 fcf-protection=
1631 Common Report Joined RejectNegative Enum(cf_protection_level) Var(flag_cf_protection) Init(CF_NONE)
1632 -fcf-protection=[full|branch|return|none] Instrument functions with checks to verify jump/call/return control-flow transfer
1633 instructions have valid targets.
1634
1635 Enum
1636 Name(cf_protection_level) Type(enum cf_protection_level) UnknownError(unknown Cotrol-Flow Protection Level %qs)
1637
1638 EnumValue
1639 Enum(cf_protection_level) String(full) Value(CF_FULL)
1640
1641 EnumValue
1642 Enum(cf_protection_level) String(branch) Value(CF_BRANCH)
1643
1644 EnumValue
1645 Enum(cf_protection_level) String(return) Value(CF_RETURN)
1646
1647 EnumValue
1648 Enum(cf_protection_level) String(none) Value(CF_NONE)
1649
1650 finstrument-functions
1651 Common Report Var(flag_instrument_function_entry_exit)
1652 Instrument function entry and exit with profiling calls.
1653
1654 finstrument-functions-exclude-function-list=
1655 Common RejectNegative Joined
1656 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions.
1657
1658 finstrument-functions-exclude-file-list=
1659 Common RejectNegative Joined
1660 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files.
1661
1662 fipa-cp
1663 Common Report Var(flag_ipa_cp) Optimization
1664 Perform interprocedural constant propagation.
1665
1666 fipa-cp-clone
1667 Common Report Var(flag_ipa_cp_clone) Optimization
1668 Perform cloning to make Interprocedural constant propagation stronger.
1669
1670 fipa-cp-alignment
1671 Common Ignore
1672 Does nothing. Preserved for backward compatibility.
1673
1674 fipa-bit-cp
1675 Common Report Var(flag_ipa_bit_cp) Optimization
1676 Perform interprocedural bitwise constant propagation.
1677
1678 fipa-profile
1679 Common Report Var(flag_ipa_profile) Init(0) Optimization
1680 Perform interprocedural profile propagation.
1681
1682 fipa-pta
1683 Common Report Var(flag_ipa_pta) Init(0) Optimization
1684 Perform interprocedural points-to analysis.
1685
1686 fipa-pure-const
1687 Common Report Var(flag_ipa_pure_const) Init(0) Optimization
1688 Discover pure and const functions.
1689
1690 fipa-icf
1691 Common Report Var(flag_ipa_icf) Optimization
1692 Perform Identical Code Folding for functions and read-only variables.
1693
1694 fipa-icf-functions
1695 Common Report Var(flag_ipa_icf_functions) Optimization
1696 Perform Identical Code Folding for functions.
1697
1698 fipa-icf-variables
1699 Common Report Var(flag_ipa_icf_variables) Optimization
1700 Perform Identical Code Folding for variables.
1701
1702 fipa-reference
1703 Common Report Var(flag_ipa_reference) Init(0) Optimization
1704 Discover readonly and non addressable static variables.
1705
1706 fipa-matrix-reorg
1707 Common Ignore
1708 Does nothing. Preserved for backward compatibility.
1709
1710 fipa-struct-reorg
1711 Common Ignore
1712 Does nothing. Preserved for backward compatibility.
1713
1714 fipa-vrp
1715 Common Report Var(flag_ipa_vrp) Optimization
1716 Perform IPA Value Range Propagation.
1717
1718 fira-algorithm=
1719 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB) Optimization
1720 -fira-algorithm=[CB|priority] Set the used IRA algorithm.
1721
1722 Enum
1723 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
1724
1725 EnumValue
1726 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
1727
1728 EnumValue
1729 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
1730
1731 fira-region=
1732 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_AUTODETECT) Optimization
1733 -fira-region=[one|all|mixed] Set regions for IRA.
1734
1735 Enum
1736 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
1737
1738 EnumValue
1739 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
1740
1741 EnumValue
1742 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
1743
1744 EnumValue
1745 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
1746
1747 fira-hoist-pressure
1748 Common Report Var(flag_ira_hoist_pressure) Init(1) Optimization
1749 Use IRA based register pressure calculation
1750 in RTL hoist optimizations.
1751
1752 fira-loop-pressure
1753 Common Report Var(flag_ira_loop_pressure) Optimization
1754 Use IRA based register pressure calculation
1755 in RTL loop optimizations.
1756
1757 fira-share-save-slots
1758 Common Report Var(flag_ira_share_save_slots) Init(1) Optimization
1759 Share slots for saving different hard registers.
1760
1761 fira-share-spill-slots
1762 Common Report Var(flag_ira_share_spill_slots) Init(1) Optimization
1763 Share stack slots for spilled pseudo-registers.
1764
1765 fira-verbose=
1766 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
1767 -fira-verbose=<number> Control IRA's level of diagnostic messages.
1768
1769 fivopts
1770 Common Report Var(flag_ivopts) Init(1) Optimization
1771 Optimize induction variables on trees.
1772
1773 fjump-tables
1774 Common Var(flag_jump_tables) Init(1) Optimization
1775 Use jump tables for sufficiently large switch statements.
1776
1777 fkeep-inline-functions
1778 Common Report Var(flag_keep_inline_functions)
1779 Generate code for functions even if they are fully inlined.
1780
1781 fkeep-static-functions
1782 Common Report Var(flag_keep_static_functions)
1783 Generate code for static functions even if they are never called.
1784
1785 fkeep-static-consts
1786 Common Report Var(flag_keep_static_consts) Init(1)
1787 Emit static const variables even if they are not used.
1788
1789 fleading-underscore
1790 Common Report Var(flag_leading_underscore) Init(-1)
1791 Give external symbols a leading underscore.
1792
1793 floop-optimize
1794 Common Ignore
1795 Does nothing. Preserved for backward compatibility.
1796
1797 flra-remat
1798 Common Report Var(flag_lra_remat) Optimization
1799 Do CFG-sensitive rematerialization in LRA.
1800
1801 flto
1802 Common
1803 Enable link-time optimization.
1804
1805 flto=
1806 Common RejectNegative Joined Var(flag_lto)
1807 Link-time optimization with number of parallel jobs or jobserver.
1808
1809 Enum
1810 Name(lto_partition_model) Type(enum lto_partition_model) UnknownError(unknown LTO partitioning model %qs)
1811
1812 EnumValue
1813 Enum(lto_partition_model) String(none) Value(LTO_PARTITION_NONE)
1814
1815 EnumValue
1816 Enum(lto_partition_model) String(one) Value(LTO_PARTITION_ONE)
1817
1818 EnumValue
1819 Enum(lto_partition_model) String(balanced) Value(LTO_PARTITION_BALANCED)
1820
1821 EnumValue
1822 Enum(lto_partition_model) String(1to1) Value(LTO_PARTITION_1TO1)
1823
1824 EnumValue
1825 Enum(lto_partition_model) String(max) Value(LTO_PARTITION_MAX)
1826
1827 flto-partition=
1828 Common Joined RejectNegative Enum(lto_partition_model) Var(flag_lto_partition) Init(LTO_PARTITION_BALANCED)
1829 Specify the algorithm to partition symbols and vars at linktime.
1830
1831 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
1832 flto-compression-level=
1833 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1) IntegerRange(0, 9)
1834 -flto-compression-level=<number> Use zlib compression level <number> for IL.
1835
1836 flto-odr-type-merging
1837 Common Report Var(flag_lto_odr_type_mering) Init(1)
1838 Merge C++ types using One Definition Rule.
1839
1840 flto-report
1841 Common Report Var(flag_lto_report) Init(0)
1842 Report various link-time optimization statistics.
1843
1844 flto-report-wpa
1845 Common Report Var(flag_lto_report_wpa) Init(0)
1846 Report various link-time optimization statistics for WPA only.
1847
1848 fmath-errno
1849 Common Report Var(flag_errno_math) Init(1) Optimization SetByCombined
1850 Set errno after built-in math functions.
1851
1852 fmax-errors=
1853 Common Joined RejectNegative UInteger Var(flag_max_errors)
1854 -fmax-errors=<number> Maximum number of errors to report.
1855
1856 fmem-report
1857 Common Report Var(mem_report)
1858 Report on permanent memory allocation.
1859
1860 fmem-report-wpa
1861 Common Report Var(mem_report_wpa)
1862 Report on permanent memory allocation in WPA only.
1863
1864 ; This will attempt to merge constant section constants, if 1 only
1865 ; string constants and constants from constant pool, if 2 also constant
1866 ; variables.
1867 fmerge-all-constants
1868 Common Report Var(flag_merge_constants,2) Init(1)
1869 Attempt to merge identical constants and constant variables.
1870
1871 fmerge-constants
1872 Common Report Var(flag_merge_constants,1)
1873 Attempt to merge identical constants across compilation units.
1874
1875 fmerge-debug-strings
1876 Common Report Var(flag_merge_debug_strings) Init(1)
1877 Attempt to merge identical debug strings across compilation units.
1878
1879 fmessage-length=
1880 Common RejectNegative Joined UInteger
1881 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping.
1882
1883 fmodulo-sched
1884 Common Report Var(flag_modulo_sched) Optimization
1885 Perform SMS based modulo scheduling before the first scheduling pass.
1886
1887 fmodulo-sched-allow-regmoves
1888 Common Report Var(flag_modulo_sched_allow_regmoves) Optimization
1889 Perform SMS based modulo scheduling with register moves allowed.
1890
1891 fmove-loop-invariants
1892 Common Report Var(flag_move_loop_invariants) Optimization
1893 Move loop invariant computations out of loops.
1894
1895 fdce
1896 Common Var(flag_dce) Init(1) Optimization
1897 Use the RTL dead code elimination pass.
1898
1899 fdse
1900 Common Var(flag_dse) Init(1) Optimization
1901 Use the RTL dead store elimination pass.
1902
1903 freschedule-modulo-scheduled-loops
1904 Common Report Var(flag_resched_modulo_sched) Optimization
1905 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling.
1906
1907 fnon-call-exceptions
1908 Common Report Var(flag_non_call_exceptions) Optimization
1909 Support synchronous non-call exceptions.
1910
1911 foffload=
1912 Common Driver Joined MissingArgError(options or targets missing after %qs)
1913 -foffload=<targets>=<options> Specify offloading targets and options for them.
1914
1915 foffload-abi=
1916 Common Joined RejectNegative Enum(offload_abi) Var(flag_offload_abi) Init(OFFLOAD_ABI_UNSET)
1917 -foffload-abi=[lp64|ilp32] Set the ABI to use in an offload compiler.
1918
1919 Enum
1920 Name(offload_abi) Type(enum offload_abi) UnknownError(unknown offload ABI %qs)
1921
1922 EnumValue
1923 Enum(offload_abi) String(ilp32) Value(OFFLOAD_ABI_ILP32)
1924
1925 EnumValue
1926 Enum(offload_abi) String(lp64) Value(OFFLOAD_ABI_LP64)
1927
1928 fomit-frame-pointer
1929 Common Report Var(flag_omit_frame_pointer) Optimization
1930 When possible do not generate stack frames.
1931
1932 fopt-info
1933 Common Report Var(flag_opt_info) Optimization
1934 Enable all optimization info dumps on stderr.
1935
1936 fopt-info-
1937 Common Joined RejectNegative Var(common_deferred_options) Defer
1938 -fopt-info[-<type>=filename] Dump compiler optimization details.
1939
1940 foptimize-register-move
1941 Common Ignore
1942 Does nothing. Preserved for backward compatibility.
1943
1944 foptimize-sibling-calls
1945 Common Report Var(flag_optimize_sibling_calls) Optimization
1946 Optimize sibling and tail recursive calls.
1947
1948 fpartial-inlining
1949 Common Report Var(flag_partial_inlining) Optimization
1950 Perform partial inlining.
1951
1952 fpre-ipa-mem-report
1953 Common Report Var(pre_ipa_mem_report)
1954 Report on memory allocation before interprocedural optimization.
1955
1956 fpost-ipa-mem-report
1957 Common Report Var(post_ipa_mem_report)
1958 Report on memory allocation before interprocedural optimization.
1959
1960 fpack-struct
1961 Common Report Var(flag_pack_struct) Optimization
1962 Pack structure members together without holes.
1963
1964 fpack-struct=
1965 Common RejectNegative Joined UInteger Optimization
1966 -fpack-struct=<number> Set initial maximum structure member alignment.
1967
1968 fpcc-struct-return
1969 Common Report Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
1970 Return small aggregates in memory, not registers.
1971
1972 fpeel-loops
1973 Common Report Var(flag_peel_loops) Optimization
1974 Perform loop peeling.
1975
1976 fpeephole
1977 Common Report Var(flag_no_peephole,0) Optimization
1978 Enable machine specific peephole optimizations.
1979
1980 fpeephole2
1981 Common Report Var(flag_peephole2) Optimization
1982 Enable an RTL peephole pass before sched2.
1983
1984 fPIC
1985 Common Report Var(flag_pic,2) Negative(fPIE) Init(-1)
1986 Generate position-independent code if possible (large mode).
1987
1988 fPIE
1989 Common Report Var(flag_pie,2) Negative(fpic) Init(-1)
1990 Generate position-independent code for executables if possible (large mode).
1991
1992 fpic
1993 Common Report Var(flag_pic,1) Negative(fpie) Init(-1)
1994 Generate position-independent code if possible (small mode).
1995
1996 fpie
1997 Common Report Var(flag_pie,1) Negative(fPIC) Init(-1)
1998 Generate position-independent code for executables if possible (small mode).
1999
2000 fplt
2001 Common Report Var(flag_plt) Init(1) Optimization
2002 Use PLT for PIC calls (-fno-plt: load the address from GOT at call site).
2003
2004 fplugin=
2005 Common Joined RejectNegative Var(common_deferred_options) Defer
2006 Specify a plugin to load.
2007
2008 fplugin-arg-
2009 Common Joined RejectNegative Var(common_deferred_options) Defer
2010 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>.
2011
2012 fpredictive-commoning
2013 Common Report Var(flag_predictive_commoning) Optimization
2014 Run predictive commoning optimization.
2015
2016 fprefetch-loop-arrays
2017 Common Report Var(flag_prefetch_loop_arrays) Init(-1) Optimization
2018 Generate prefetch instructions, if available, for arrays in loops.
2019
2020 fprofile
2021 Common Report Var(profile_flag)
2022 Enable basic program profiling code.
2023
2024 fprofile-abs-path
2025 Common Report Var(profile_abs_path_flag)
2026 Generate absolute source path names for gcov.
2027
2028 fprofile-arcs
2029 Common Report Var(profile_arc_flag)
2030 Insert arc-based program profiling code.
2031
2032 fprofile-dir=
2033 Common Joined RejectNegative Var(profile_data_prefix)
2034 Set the top-level directory for storing the profile data.
2035 The default is 'pwd'.
2036
2037 fprofile-correction
2038 Common Report Var(flag_profile_correction)
2039 Enable correction of flow inconsistent profile data input.
2040
2041 fprofile-update=
2042 Common Joined RejectNegative Enum(profile_update) Var(flag_profile_update) Init(PROFILE_UPDATE_SINGLE)
2043 -fprofile-update=[single|atomic|prefer-atomic] Set the profile update method.
2044
2045 Enum
2046 Name(profile_update) Type(enum profile_update) UnknownError(unknown profile update method %qs)
2047
2048 EnumValue
2049 Enum(profile_update) String(single) Value(PROFILE_UPDATE_SINGLE)
2050
2051 EnumValue
2052 Enum(profile_update) String(atomic) Value(PROFILE_UPDATE_ATOMIC)
2053
2054 EnumValue
2055 Enum(profile_update) String(prefer-atomic) Value(PROFILE_UPDATE_PREFER_ATOMIC)
2056
2057 fprofile-generate
2058 Common
2059 Enable common options for generating profile info for profile feedback directed optimizations.
2060
2061 fprofile-generate=
2062 Common Joined RejectNegative
2063 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=.
2064
2065 fprofile-use
2066 Common Var(flag_profile_use)
2067 Enable common options for performing profile feedback directed optimizations.
2068
2069 fprofile-use=
2070 Common Joined RejectNegative
2071 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=.
2072
2073 fprofile-values
2074 Common Report Var(flag_profile_values)
2075 Insert code to profile values of expressions.
2076
2077 fprofile-report
2078 Common Report Var(profile_report)
2079 Report on consistency of profile.
2080
2081 fprofile-reorder-functions
2082 Common Report Var(flag_profile_reorder_functions)
2083 Enable function reordering that improves code placement.
2084
2085 fpatchable-function-entry=
2086 Common Joined Optimization
2087 Insert NOP instructions at each function entry.
2088
2089 frandom-seed
2090 Common Var(common_deferred_options) Defer
2091
2092 frandom-seed=
2093 Common Joined RejectNegative Var(common_deferred_options) Defer
2094 -frandom-seed=<string> Make compile reproducible using <string>.
2095
2096 ; This switch causes the command line that was used to create an
2097 ; object file to be recorded into the object file. The exact format
2098 ; of this recording is target and binary file format dependent.
2099 ; It is related to the -fverbose-asm switch, but that switch only
2100 ; records information in the assembler output file as comments, so
2101 ; they never reach the object file.
2102 frecord-gcc-switches
2103 Common Report Var(flag_record_gcc_switches)
2104 Record gcc command line switches in the object file.
2105
2106 freg-struct-return
2107 Common Report Var(flag_pcc_struct_return,0) Optimization
2108 Return small aggregates in registers.
2109
2110 fregmove
2111 Common Ignore
2112 Does nothing. Preserved for backward compatibility.
2113
2114 flifetime-dse
2115 Common Report Var(flag_lifetime_dse,2) Init(2) Optimization
2116 Tell DSE that the storage for a C++ object is dead when the constructor
2117 starts and when the destructor finishes.
2118
2119 flifetime-dse=
2120 Common Joined RejectNegative UInteger Var(flag_lifetime_dse) Optimization IntegerRange(0, 2)
2121
2122 flive-range-shrinkage
2123 Common Report Var(flag_live_range_shrinkage) Init(0) Optimization
2124 Relief of register pressure through live range shrinkage.
2125
2126 frename-registers
2127 Common Report Var(flag_rename_registers) Init(2) Optimization
2128 Perform a register renaming optimization pass.
2129
2130 fschedule-fusion
2131 Common Report Var(flag_schedule_fusion) Init(2) Optimization
2132 Perform a target dependent instruction fusion optimization pass.
2133
2134 freorder-blocks
2135 Common Report Var(flag_reorder_blocks) Optimization
2136 Reorder basic blocks to improve code placement.
2137
2138 freorder-blocks-algorithm=
2139 Common Joined RejectNegative Enum(reorder_blocks_algorithm) Var(flag_reorder_blocks_algorithm) Init(REORDER_BLOCKS_ALGORITHM_SIMPLE) Optimization
2140 -freorder-blocks-algorithm=[simple|stc] Set the used basic block reordering algorithm.
2141
2142 Enum
2143 Name(reorder_blocks_algorithm) Type(enum reorder_blocks_algorithm) UnknownError(unknown basic block reordering algorithm %qs)
2144
2145 EnumValue
2146 Enum(reorder_blocks_algorithm) String(simple) Value(REORDER_BLOCKS_ALGORITHM_SIMPLE)
2147
2148 EnumValue
2149 Enum(reorder_blocks_algorithm) String(stc) Value(REORDER_BLOCKS_ALGORITHM_STC)
2150
2151 freorder-blocks-and-partition
2152 Common Report Var(flag_reorder_blocks_and_partition) Optimization
2153 Reorder basic blocks and partition into hot and cold sections.
2154
2155 freorder-functions
2156 Common Report Var(flag_reorder_functions) Optimization
2157 Reorder functions to improve code placement.
2158
2159 frerun-cse-after-loop
2160 Common Report Var(flag_rerun_cse_after_loop) Optimization
2161 Add a common subexpression elimination pass after loop optimizations.
2162
2163 frerun-loop-opt
2164 Common Ignore
2165 Does nothing. Preserved for backward compatibility.
2166
2167 frounding-math
2168 Common Report Var(flag_rounding_math) Optimization SetByCombined
2169 Disable optimizations that assume default FP rounding behavior.
2170
2171 fsched-interblock
2172 Common Report Var(flag_schedule_interblock) Init(1) Optimization
2173 Enable scheduling across basic blocks.
2174
2175 fsched-pressure
2176 Common Report Var(flag_sched_pressure) Init(0) Optimization
2177 Enable register pressure sensitive insn scheduling.
2178
2179 fsched-spec
2180 Common Report Var(flag_schedule_speculative) Init(1) Optimization
2181 Allow speculative motion of non-loads.
2182
2183 fsched-spec-load
2184 Common Report Var(flag_schedule_speculative_load) Optimization
2185 Allow speculative motion of some loads.
2186
2187 fsched-spec-load-dangerous
2188 Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
2189 Allow speculative motion of more loads.
2190
2191 fsched-verbose=
2192 Common RejectNegative Joined UInteger Var(sched_verbose_param) Init(1)
2193 -fsched-verbose=<number> Set the verbosity level of the scheduler.
2194
2195 fsched2-use-superblocks
2196 Common Report Var(flag_sched2_use_superblocks) Optimization
2197 If scheduling post reload, do superblock scheduling.
2198
2199 fsched2-use-traces
2200 Common Ignore
2201 Does nothing. Preserved for backward compatibility.
2202
2203 fschedule-insns
2204 Common Report Var(flag_schedule_insns) Optimization
2205 Reschedule instructions before register allocation.
2206
2207 fschedule-insns2
2208 Common Report Var(flag_schedule_insns_after_reload) Optimization
2209 Reschedule instructions after register allocation.
2210
2211 ; This flag should be on when a target implements non-trivial
2212 ; scheduling hooks, maybe saving some information for its own sake.
2213 ; On IA64, for example, this is used for correct bundling.
2214 fselective-scheduling
2215 Common Report Var(flag_selective_scheduling) Optimization
2216 Schedule instructions using selective scheduling algorithm.
2217
2218 fselective-scheduling2
2219 Common Report Var(flag_selective_scheduling2) Optimization
2220 Run selective scheduling after reload.
2221
2222 fself-test=
2223 Common Undocumented Joined Var(flag_self_test)
2224 Run self-tests, using the given path to locate test files.
2225
2226 fsel-sched-pipelining
2227 Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization
2228 Perform software pipelining of inner loops during selective scheduling.
2229
2230 fsel-sched-pipelining-outer-loops
2231 Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
2232 Perform software pipelining of outer loops during selective scheduling.
2233
2234 fsel-sched-reschedule-pipelined
2235 Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
2236 Reschedule pipelined regions without pipelining.
2237
2238 fsemantic-interposition
2239 Common Report Var(flag_semantic_interposition) Init(1)
2240 Allow interposing function (or variables) by ones with different semantics (or initializer) respectively by dynamic linker.
2241
2242 ; sched_stalled_insns means that insns can be moved prematurely from the queue
2243 ; of stalled insns into the ready list.
2244 fsched-stalled-insns
2245 Common Report Var(flag_sched_stalled_insns) Optimization UInteger
2246 Allow premature scheduling of queued insns.
2247
2248 fsched-stalled-insns=
2249 Common RejectNegative Joined UInteger Optimization
2250 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled.
2251
2252 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
2253 ; be examined for a dependency on a stalled insn that is candidate for
2254 ; premature removal from the queue of stalled insns into the ready list (has
2255 ; an effect only if the flag 'sched_stalled_insns' is set).
2256 fsched-stalled-insns-dep
2257 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
2258 Set dependence distance checking in premature scheduling of queued insns.
2259
2260 fsched-stalled-insns-dep=
2261 Common RejectNegative Joined UInteger Optimization
2262 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns.
2263
2264 fsched-group-heuristic
2265 Common Report Var(flag_sched_group_heuristic) Init(1) Optimization
2266 Enable the group heuristic in the scheduler.
2267
2268 fsched-critical-path-heuristic
2269 Common Report Var(flag_sched_critical_path_heuristic) Init(1) Optimization
2270 Enable the critical path heuristic in the scheduler.
2271
2272 fsched-spec-insn-heuristic
2273 Common Report Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
2274 Enable the speculative instruction heuristic in the scheduler.
2275
2276 fsched-rank-heuristic
2277 Common Report Var(flag_sched_rank_heuristic) Init(1) Optimization
2278 Enable the rank heuristic in the scheduler.
2279
2280 fsched-last-insn-heuristic
2281 Common Report Var(flag_sched_last_insn_heuristic) Init(1) Optimization
2282 Enable the last instruction heuristic in the scheduler.
2283
2284 fsched-dep-count-heuristic
2285 Common Report Var(flag_sched_dep_count_heuristic) Init(1) Optimization
2286 Enable the dependent count heuristic in the scheduler.
2287
2288 fsection-anchors
2289 Common Report Var(flag_section_anchors) Optimization
2290 Access data in the same section from shared anchor points.
2291
2292 fsee
2293 Common Ignore
2294 Does nothing. Preserved for backward compatibility.
2295
2296 fzee
2297 Common Ignore
2298 Does nothing. Preserved for backward compatibility.
2299
2300 free
2301 Common Report Var(flag_ree) Init(0)
2302 Turn on Redundant Extensions Elimination pass.
2303
2304 fshow-column
2305 Common Report Var(flag_show_column) Init(1)
2306 Show column numbers in diagnostics, when available. Default on.
2307
2308 fshrink-wrap
2309 Common Report Var(flag_shrink_wrap) Optimization
2310 Emit function prologues only before parts of the function that need it,
2311 rather than at the top of the function.
2312
2313 fshrink-wrap-separate
2314 Common Report Var(flag_shrink_wrap_separate) Init(1) Optimization
2315 Shrink-wrap parts of the prologue and epilogue separately.
2316
2317 fsignaling-nans
2318 Common Report Var(flag_signaling_nans) Optimization SetByCombined
2319 Disable optimizations observable by IEEE signaling NaNs.
2320
2321 fsigned-zeros
2322 Common Report Var(flag_signed_zeros) Init(1) Optimization SetByCombined
2323 Disable floating point optimizations that ignore the IEEE signedness of zero.
2324
2325 fsingle-precision-constant
2326 Common Report Var(flag_single_precision_constant) Optimization
2327 Convert floating point constants to single precision constants.
2328
2329 fsplit-ivs-in-unroller
2330 Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
2331 Split lifetimes of induction variables when loops are unrolled.
2332
2333 fsplit-stack
2334 Common Report Var(flag_split_stack) Init(-1)
2335 Generate discontiguous stack frames.
2336
2337 fsplit-wide-types
2338 Common Report Var(flag_split_wide_types) Optimization
2339 Split wide types into independent registers.
2340
2341 fssa-backprop
2342 Common Report Var(flag_ssa_backprop) Init(1) Optimization
2343 Enable backward propagation of use properties at the SSA level.
2344
2345 fssa-phiopt
2346 Common Report Var(flag_ssa_phiopt) Optimization
2347 Optimize conditional patterns using SSA PHI nodes.
2348
2349 fstdarg-opt
2350 Common Report Var(flag_stdarg_opt) Init(1) Optimization
2351 Optimize amount of stdarg registers saved to stack at start of function.
2352
2353 fvariable-expansion-in-unroller
2354 Common Report Var(flag_variable_expansion_in_unroller) Optimization
2355 Apply variable expansion when loops are unrolled.
2356
2357 fstack-check=
2358 Common Report RejectNegative Joined Optimization
2359 -fstack-check=[no|generic|specific] Insert stack checking code into the program.
2360
2361 fstack-check
2362 Common Alias(fstack-check=, specific, no)
2363 Insert stack checking code into the program. Same as -fstack-check=specific.
2364
2365 fstack-clash-protection
2366 Common Report Var(flag_stack_clash_protection) Optimization
2367 Insert code to probe each page of stack space as it is allocated to protect
2368 from stack-clash style attacks.
2369
2370 fstack-limit
2371 Common Var(common_deferred_options) Defer
2372
2373 fstack-limit-register=
2374 Common RejectNegative Joined Var(common_deferred_options) Defer
2375 -fstack-limit-register=<register> Trap if the stack goes past <register>.
2376
2377 fstack-limit-symbol=
2378 Common RejectNegative Joined Var(common_deferred_options) Defer
2379 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>.
2380
2381 fstack-protector
2382 Common Report Var(flag_stack_protect, 1) Init(-1) Optimization
2383 Use propolice as a stack protection method.
2384
2385 fstack-protector-all
2386 Common Report RejectNegative Var(flag_stack_protect, 2) Init(-1) Optimization
2387 Use a stack protection method for every function.
2388
2389 fstack-protector-strong
2390 Common Report RejectNegative Var(flag_stack_protect, 3) Init(-1) Optimization
2391 Use a smart stack protection method for certain functions.
2392
2393 fstack-protector-explicit
2394 Common Report RejectNegative Var(flag_stack_protect, 4) Optimization
2395 Use stack protection method only for functions with the stack_protect attribute.
2396
2397 fstack-usage
2398 Common RejectNegative Var(flag_stack_usage)
2399 Output stack usage information on a per-function basis.
2400
2401 fstrength-reduce
2402 Common Ignore
2403 Does nothing. Preserved for backward compatibility.
2404
2405 ; Nonzero if we should do (language-dependent) alias analysis.
2406 ; Typically, this analysis will assume that expressions of certain
2407 ; types do not alias expressions of certain other types. Only used
2408 ; if alias analysis (in general) is enabled.
2409 fstrict-aliasing
2410 Common Report Var(flag_strict_aliasing) Optimization
2411 Assume strict aliasing rules apply.
2412
2413 fstrict-overflow
2414 Common NegativeAlias Alias(fwrapv)
2415 Treat signed overflow as undefined. Negated as -fwrapv.
2416
2417 fsync-libcalls
2418 Common Report Var(flag_sync_libcalls) Init(1)
2419 Implement __atomic operations via libcalls to legacy __sync functions.
2420
2421 fsyntax-only
2422 Common Report Var(flag_syntax_only)
2423 Check for syntax errors, then stop.
2424
2425 ftest-coverage
2426 Common Report Var(flag_test_coverage)
2427 Create data files needed by \"gcov\".
2428
2429 fthread-jumps
2430 Common Report Var(flag_thread_jumps) Optimization
2431 Perform jump threading optimizations.
2432
2433 ftime-report
2434 Common Report Var(time_report)
2435 Report the time taken by each compiler pass.
2436
2437 ftime-report-details
2438 Common Report Var(time_report_details)
2439 Record times taken by sub-phases separately.
2440
2441 ftls-model=
2442 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
2443 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model.
2444
2445 Enum
2446 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
2447
2448 EnumValue
2449 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
2450
2451 EnumValue
2452 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
2453
2454 EnumValue
2455 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
2456
2457 EnumValue
2458 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
2459
2460 ftoplevel-reorder
2461 Common Report Var(flag_toplevel_reorder) Init(2)
2462 Reorder top level functions, variables, and asms.
2463
2464 ftracer
2465 Common Report Var(flag_tracer) Optimization
2466 Perform superblock formation via tail duplication.
2467
2468 ftrampolines
2469 Common Report Var(flag_trampolines) Init(0)
2470 For targets that normally need trampolines for nested functions, always
2471 generate them instead of using descriptors.
2472
2473 ; Zero means that floating-point math operations cannot generate a
2474 ; (user-visible) trap. This is the case, for example, in nonstop
2475 ; IEEE 754 arithmetic.
2476 ftrapping-math
2477 Common Report Var(flag_trapping_math) Init(1) Optimization SetByCombined
2478 Assume floating-point operations can trap.
2479
2480 ftrapv
2481 Common Report Var(flag_trapv) Optimization
2482 Trap for signed overflow in addition, subtraction and multiplication.
2483
2484 ftree-ccp
2485 Common Report Var(flag_tree_ccp) Optimization
2486 Enable SSA-CCP optimization on trees.
2487
2488 ftree-bit-ccp
2489 Common Report Var(flag_tree_bit_ccp) Optimization
2490 Enable SSA-BIT-CCP optimization on trees.
2491
2492 ftree-store-ccp
2493 Common Ignore
2494 Does nothing. Preserved for backward compatibility.
2495
2496 ftree-ch
2497 Common Report Var(flag_tree_ch) Optimization
2498 Enable loop header copying on trees.
2499
2500 ftree-coalesce-inlined-vars
2501 Common Ignore RejectNegative
2502 Does nothing. Preserved for backward compatibility.
2503
2504 ftree-coalesce-vars
2505 Common Report Var(flag_tree_coalesce_vars) Optimization
2506 Enable SSA coalescing of user variables.
2507
2508 ftree-copyrename
2509 Common Ignore
2510 Does nothing. Preserved for backward compatibility.
2511
2512 ftree-copy-prop
2513 Common Report Var(flag_tree_copy_prop) Optimization
2514 Enable copy propagation on trees.
2515
2516 ftree-store-copy-prop
2517 Common Ignore
2518 Does nothing. Preserved for backward compatibility.
2519
2520 ftree-cselim
2521 Common Report Var(flag_tree_cselim) Init(2) Optimization
2522 Transform condition stores into unconditional ones.
2523
2524 ftree-switch-conversion
2525 Common Report Var(flag_tree_switch_conversion) Optimization
2526 Perform conversions of switch initializations.
2527
2528 ftree-dce
2529 Common Report Var(flag_tree_dce) Optimization
2530 Enable SSA dead code elimination optimization on trees.
2531
2532 ftree-dominator-opts
2533 Common Report Var(flag_tree_dom) Optimization
2534 Enable dominator optimizations.
2535
2536 ftree-tail-merge
2537 Common Report Var(flag_tree_tail_merge) Optimization
2538 Enable tail merging on trees.
2539
2540 ftree-dse
2541 Common Report Var(flag_tree_dse) Optimization
2542 Enable dead store elimination.
2543
2544 ftree-forwprop
2545 Common Report Var(flag_tree_forwprop) Init(1) Optimization
2546 Enable forward propagation on trees.
2547
2548 ftree-fre
2549 Common Report Var(flag_tree_fre) Optimization
2550 Enable Full Redundancy Elimination (FRE) on trees.
2551
2552 foptimize-strlen
2553 Common Report Var(flag_optimize_strlen) Optimization
2554 Enable string length optimizations on trees.
2555
2556 fisolate-erroneous-paths-dereference
2557 Common Report Var(flag_isolate_erroneous_paths_dereference) Optimization
2558 Detect paths that trigger erroneous or undefined behavior due to
2559 dereferencing a null pointer. Isolate those paths from the main control
2560 flow and turn the statement with erroneous or undefined behavior into a trap.
2561
2562 fisolate-erroneous-paths-attribute
2563 Common Report Var(flag_isolate_erroneous_paths_attribute) Optimization
2564 Detect paths that trigger erroneous or undefined behavior due to a null value
2565 being used in a way forbidden by a returns_nonnull or nonnull
2566 attribute. Isolate those paths from the main control flow and turn the
2567 statement with erroneous or undefined behavior into a trap.
2568
2569 ftree-loop-distribution
2570 Common Report Var(flag_tree_loop_distribution) Optimization
2571 Enable loop distribution on trees.
2572
2573 ftree-loop-distribute-patterns
2574 Common Report Var(flag_tree_loop_distribute_patterns) Optimization
2575 Enable loop distribution for patterns transformed into a library call.
2576
2577 ftree-loop-im
2578 Common Report Var(flag_tree_loop_im) Init(1) Optimization
2579 Enable loop invariant motion on trees.
2580
2581 ftree-loop-linear
2582 Common Alias(floop-nest-optimize)
2583 Enable loop nest transforms. Same as -floop-nest-optimize.
2584
2585 ftree-loop-ivcanon
2586 Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
2587 Create canonical induction variables in loops.
2588
2589 ftree-loop-optimize
2590 Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
2591 Enable loop optimizations on tree level.
2592
2593 ftree-parallelize-loops=
2594 Common Report Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1) Optimization
2595 -ftree-parallelize-loops=<number> Enable automatic parallelization of loops.
2596
2597 ftree-phiprop
2598 Common Report Var(flag_tree_phiprop) Init(1) Optimization
2599 Enable hoisting loads from conditional pointers.
2600
2601 ftree-pre
2602 Common Report Var(flag_tree_pre) Optimization
2603 Enable SSA-PRE optimization on trees.
2604
2605 ftree-partial-pre
2606 Common Report Var(flag_tree_partial_pre) Optimization
2607 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination.
2608
2609 ftree-pta
2610 Common Report Var(flag_tree_pta) Optimization
2611 Perform function-local points-to analysis on trees.
2612
2613 ftree-reassoc
2614 Common Report Var(flag_tree_reassoc) Init(1) Optimization
2615 Enable reassociation on tree level.
2616
2617 ftree-salias
2618 Common Ignore
2619 Does nothing. Preserved for backward compatibility.
2620
2621 ftree-sink
2622 Common Report Var(flag_tree_sink) Optimization
2623 Enable SSA code sinking on trees.
2624
2625 ftree-slsr
2626 Common Report Var(flag_tree_slsr) Optimization
2627 Perform straight-line strength reduction.
2628
2629 ftree-sra
2630 Common Report Var(flag_tree_sra) Optimization
2631 Perform scalar replacement of aggregates.
2632
2633 ftree-ter
2634 Common Report Var(flag_tree_ter) Optimization
2635 Replace temporary expressions in the SSA->normal pass.
2636
2637 ftree-lrs
2638 Common Report Var(flag_tree_live_range_split) Optimization
2639 Perform live range splitting during the SSA->normal pass.
2640
2641 ftree-vrp
2642 Common Report Var(flag_tree_vrp) Init(0) Optimization
2643 Perform Value Range Propagation on trees.
2644
2645 fsplit-paths
2646 Common Report Var(flag_split_paths) Init(0) Optimization
2647 Split paths leading to loop backedges.
2648
2649 funconstrained-commons
2650 Common Var(flag_unconstrained_commons) Optimization
2651 Assume common declarations may be overridden with ones with a larger
2652 trailing array.
2653
2654 funit-at-a-time
2655 Common Report Var(flag_unit_at_a_time) Init(1)
2656 Compile whole compilation unit at a time.
2657
2658 funroll-loops
2659 Common Report Var(flag_unroll_loops) Optimization
2660 Perform loop unrolling when iteration count is known.
2661
2662 funroll-all-loops
2663 Common Report Var(flag_unroll_all_loops) Optimization
2664 Perform loop unrolling for all loops.
2665
2666 ; Nonzero means that loop optimizer may assume that the induction variables
2667 ; that control loops do not overflow and that the loops with nontrivial
2668 ; exit condition are not infinite
2669 funsafe-loop-optimizations
2670 Common Ignore
2671 Does nothing. Preserved for backward compatibility.
2672
2673 fassociative-math
2674 Common Report Var(flag_associative_math) SetByCombined Optimization
2675 Allow optimization for floating-point arithmetic which may change the
2676 result of the operation due to rounding.
2677
2678 freciprocal-math
2679 Common Report Var(flag_reciprocal_math) SetByCombined Optimization
2680 Same as -fassociative-math for expressions which include division.
2681
2682 ; Nonzero means that unsafe floating-point math optimizations are allowed
2683 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
2684 ; are allowed to assume that their arguments and results are "normal"
2685 ; (e.g., nonnegative for SQRT).
2686 funsafe-math-optimizations
2687 Common Report Var(flag_unsafe_math_optimizations) Optimization SetByCombined
2688 Allow math optimizations that may violate IEEE or ISO standards.
2689
2690 funswitch-loops
2691 Common Report Var(flag_unswitch_loops) Optimization
2692 Perform loop unswitching.
2693
2694 fsplit-loops
2695 Common Report Var(flag_split_loops) Optimization
2696 Perform loop splitting.
2697
2698 funwind-tables
2699 Common Report Var(flag_unwind_tables) Optimization
2700 Just generate unwind tables for exception handling.
2701
2702 fuse-ld=bfd
2703 Common Driver Negative(fuse-ld=gold)
2704 Use the bfd linker instead of the default linker.
2705
2706 fuse-ld=gold
2707 Common Driver Negative(fuse-ld=bfd)
2708 Use the gold linker instead of the default linker.
2709
2710 fuse-linker-plugin
2711 Common Undocumented Var(flag_use_linker_plugin)
2712
2713 ; Positive if we should track variables, negative if we should run
2714 ; the var-tracking pass only to discard debug annotations, zero if
2715 ; we're not to run it. When flag_var_tracking == 2 (AUTODETECT_VALUE) it
2716 ; will be set according to optimize, debug_info_level and debug_hooks
2717 ; in process_options ().
2718 fvar-tracking
2719 Common Report Var(flag_var_tracking) Init(2) PerFunction
2720 Perform variable tracking.
2721
2722 ; Positive if we should track variables at assignments, negative if
2723 ; we should run the var-tracking pass only to discard debug
2724 ; annotations. When flag_var_tracking_assignments ==
2725 ; AUTODETECT_VALUE it will be set according to flag_var_tracking.
2726 fvar-tracking-assignments
2727 Common Report Var(flag_var_tracking_assignments) Init(2) PerFunction
2728 Perform variable tracking by annotating assignments.
2729
2730 ; Nonzero if we should toggle flag_var_tracking_assignments after
2731 ; processing options and computing its default. */
2732 fvar-tracking-assignments-toggle
2733 Common Report Var(flag_var_tracking_assignments_toggle) PerFunction
2734 Toggle -fvar-tracking-assignments.
2735
2736 ; Positive if we should track uninitialized variables, negative if
2737 ; we should run the var-tracking pass only to discard debug
2738 ; annotations. When flag_var_tracking_uninit == AUTODETECT_VALUE it
2739 ; will be set according to flag_var_tracking.
2740 fvar-tracking-uninit
2741 Common Report Var(flag_var_tracking_uninit) PerFunction
2742 Perform variable tracking and also tag variables that are uninitialized.
2743
2744 ; Alias to enable both -ftree-loop-vectorize and -ftree-slp-vectorize.
2745 ftree-vectorize
2746 Common Report Optimization
2747 Enable vectorization on trees.
2748
2749 ftree-vectorizer-verbose=
2750 Common Joined RejectNegative Ignore
2751 Does nothing. Preserved for backward compatibility.
2752
2753 ftree-loop-vectorize
2754 Common Report Var(flag_tree_loop_vectorize) Optimization EnabledBy(ftree-vectorize)
2755 Enable loop vectorization on trees.
2756
2757 ftree-slp-vectorize
2758 Common Report Var(flag_tree_slp_vectorize) Optimization EnabledBy(ftree-vectorize)
2759 Enable basic block vectorization (SLP) on trees.
2760
2761 fvect-cost-model=
2762 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_vect_cost_model) Init(VECT_COST_MODEL_DEFAULT) Optimization
2763 Specifies the cost model for vectorization.
2764 -fvect-cost-model=[unlimited|dynamic|cheap] Specifies the cost model for vectorization.
2765
2766 fsimd-cost-model=
2767 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_simd_cost_model) Init(VECT_COST_MODEL_UNLIMITED) Optimization
2768 -fsimd-cost-model=[unlimited|dynamic|cheap] Specifies the vectorization cost model for code marked with a simd directive.
2769
2770 Enum
2771 Name(vect_cost_model) Type(enum vect_cost_model) UnknownError(unknown vectorizer cost model %qs)
2772
2773 EnumValue
2774 Enum(vect_cost_model) String(unlimited) Value(VECT_COST_MODEL_UNLIMITED)
2775
2776 EnumValue
2777 Enum(vect_cost_model) String(dynamic) Value(VECT_COST_MODEL_DYNAMIC)
2778
2779 EnumValue
2780 Enum(vect_cost_model) String(cheap) Value(VECT_COST_MODEL_CHEAP)
2781
2782 fvect-cost-model
2783 Common Alias(fvect-cost-model=,dynamic,unlimited)
2784 Enables the dynamic vectorizer cost model. Preserved for backward compatibility.
2785
2786 ftree-vect-loop-version
2787 Common Ignore
2788 Does nothing. Preserved for backward compatibility.
2789
2790 ftree-scev-cprop
2791 Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
2792 Enable copy propagation of scalar-evolution information.
2793
2794 ; -fverbose-asm causes extra commentary information to be produced in
2795 ; the generated assembly code (to make it more readable). This option
2796 ; is generally only of use to those who actually need to read the
2797 ; generated assembly code (perhaps while debugging the compiler itself).
2798 ; -fno-verbose-asm, the default, causes the extra information
2799 ; to not be added and is useful when comparing two assembler files.
2800 fverbose-asm
2801 Common Report Var(flag_verbose_asm)
2802 Add extra commentary to assembler output.
2803
2804 fvisibility=
2805 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
2806 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility.
2807
2808 Enum
2809 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
2810
2811 EnumValue
2812 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
2813
2814 EnumValue
2815 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
2816
2817 EnumValue
2818 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
2819
2820 EnumValue
2821 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
2822
2823 fvtable-verify=
2824 Common Joined RejectNegative Enum(vtv_priority) Var(flag_vtable_verify) Init(VTV_NO_PRIORITY)
2825 Validate vtable pointers before using them.
2826
2827 Enum
2828 Name(vtv_priority) Type(enum vtv_priority) UnknownError(unknown vtable verify initialization priority %qs)
2829
2830 EnumValue
2831 Enum(vtv_priority) String(none) Value(VTV_NO_PRIORITY)
2832
2833 EnumValue
2834 Enum(vtv_priority) String(std) Value(VTV_STANDARD_PRIORITY)
2835
2836 EnumValue
2837 Enum(vtv_priority) String(preinit) Value(VTV_PREINIT_PRIORITY)
2838
2839 fvtv-counts
2840 Common Var(flag_vtv_counts)
2841 Output vtable verification counters.
2842
2843 fvtv-debug
2844 Common Var(flag_vtv_debug)
2845 Output vtable verification pointer sets information.
2846
2847 fvpt
2848 Common Report Var(flag_value_profile_transformations) Optimization
2849 Use expression value profiles in optimizations.
2850
2851 fweb
2852 Common Report Var(flag_web) Init(2) Optimization
2853 Construct webs and split unrelated uses of single variable.
2854
2855 ftree-builtin-call-dce
2856 Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization
2857 Enable conditional dead code elimination for builtin calls.
2858
2859 fwhole-program
2860 Common Report Var(flag_whole_program) Init(0)
2861 Perform whole program optimizations.
2862
2863 fwrapv
2864 Common Report Var(flag_wrapv) Optimization
2865 Assume signed arithmetic overflow wraps around.
2866
2867 fzero-initialized-in-bss
2868 Common Report Var(flag_zero_initialized_in_bss) Init(1)
2869 Put zero initialized data in the bss section.
2870
2871 g
2872 Common Driver RejectNegative JoinedOrMissing
2873 Generate debug information in default format.
2874
2875 gcoff
2876 Common Driver Ignore Warn(switch %qs no longer supported)
2877 Does nothing. Preserved for backward compatibility.
2878
2879 gcoff1
2880 Common Driver Ignore Warn(switch %qs no longer supported)
2881 Does nothing. Preserved for backward compatibility.
2882
2883 gcoff2
2884 Common Driver Ignore Warn(switch %qs no longer supported)
2885 Does nothing. Preserved for backward compatibility.
2886
2887 gcoff3
2888 Common Driver Ignore Warn(switch %qs no longer supported)
2889 Does nothing. Preserved for backward compatibility.
2890
2891 gcolumn-info
2892 Common Driver Var(debug_column_info,1) Init(1)
2893 Record DW_AT_decl_column and DW_AT_call_column in DWARF.
2894
2895 gdwarf
2896 Common Driver JoinedOrMissing Negative(gdwarf-)
2897 Generate debug information in default version of DWARF format.
2898
2899 gdwarf-
2900 Common Driver Joined UInteger Var(dwarf_version) Init(4) Negative(gstabs)
2901 Generate debug information in DWARF v2 (or later) format.
2902
2903 ggdb
2904 Common Driver JoinedOrMissing
2905 Generate debug information in default extended format.
2906
2907 gno-
2908 RejectNegative Joined Undocumented
2909 ; Catch the gno- prefix, so it doesn't backtrack to g<level>.
2910
2911 gno-pubnames
2912 Common Driver Negative(gpubnames) Var(debug_generate_pub_sections, 0) Init(-1)
2913 Don't generate DWARF pubnames and pubtypes sections.
2914
2915 gpubnames
2916 Common Driver Negative(ggnu-pubnames) Var(debug_generate_pub_sections, 1)
2917 Generate DWARF pubnames and pubtypes sections.
2918
2919 ggnu-pubnames
2920 Common Driver Negative(gno-pubnames) Var(debug_generate_pub_sections, 2)
2921 Generate DWARF pubnames and pubtypes sections with GNU extensions.
2922
2923 grecord-gcc-switches
2924 Common Driver Var(dwarf_record_gcc_switches) Init(1)
2925 Record gcc command line switches in DWARF DW_AT_producer.
2926
2927 gsplit-dwarf
2928 Common Driver Var(dwarf_split_debug_info) Init(0)
2929 Generate debug information in separate .dwo files.
2930
2931 gstabs
2932 Common Driver JoinedOrMissing Negative(gstabs+)
2933 Generate debug information in STABS format.
2934
2935 gstabs+
2936 Common Driver JoinedOrMissing Negative(gvms)
2937 Generate debug information in extended STABS format.
2938
2939 gstatement-frontiers
2940 Common Driver Var(debug_nonbind_markers_p) Init(2)
2941 Emit progressive recommended breakpoint locations.
2942
2943 gstrict-dwarf
2944 Common Driver Report Var(dwarf_strict) Init(0)
2945 Don't emit DWARF additions beyond selected version.
2946
2947 gtoggle
2948 Common Driver Report Var(flag_gtoggle)
2949 Toggle debug information generation.
2950
2951 gvms
2952 Common Driver JoinedOrMissing Negative(gxcoff)
2953 Generate debug information in VMS format.
2954
2955 gxcoff
2956 Common Driver JoinedOrMissing Negative(gxcoff+)
2957 Generate debug information in XCOFF format.
2958
2959 gxcoff+
2960 Common Driver JoinedOrMissing Negative(gdwarf)
2961 Generate debug information in extended XCOFF format.
2962
2963 Enum
2964 Name(compressed_debug_sections) Type(int)
2965
2966 ; Since -gz= is completely handled in specs, the values aren't used and we
2967 ; assign arbitrary constants.
2968 EnumValue
2969 Enum(compressed_debug_sections) String(none) Value(0)
2970
2971 EnumValue
2972 Enum(compressed_debug_sections) String(zlib) Value(1)
2973
2974 EnumValue
2975 Enum(compressed_debug_sections) String(zlib-gnu) Value(2)
2976
2977 gz
2978 Common Driver
2979 Generate compressed debug sections.
2980
2981 gz=
2982 Common Driver RejectNegative Joined Enum(compressed_debug_sections)
2983 -gz=<format> Generate compressed debug sections in format <format>.
2984
2985 h
2986 Driver Joined Separate
2987
2988 iplugindir=
2989 Common Joined Var(plugindir_string) Init(0)
2990 -iplugindir=<dir> Set <dir> to be the default plugin directory.
2991
2992 imultiarch
2993 Common Joined Separate RejectDriver Var(imultiarch) Init(0)
2994 -imultiarch <dir> Set <dir> to be the multiarch include subdirectory.
2995
2996 l
2997 Driver Joined Separate
2998
2999 n
3000 Driver
3001
3002 no-canonical-prefixes
3003 Driver
3004
3005 nodefaultlibs
3006 Driver
3007
3008 nostartfiles
3009 Driver
3010
3011 nostdlib
3012 Driver
3013
3014 o
3015 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
3016 -o <file> Place output into <file>.
3017
3018 p
3019 Common Var(profile_flag)
3020 Enable function profiling.
3021
3022 pass-exit-codes
3023 Driver Var(pass_exit_codes)
3024
3025 pedantic
3026 Common Alias(Wpedantic)
3027
3028 pedantic-errors
3029 Common Var(flag_pedantic_errors)
3030 Like -pedantic but issue them as errors.
3031
3032 pg
3033 Driver
3034
3035 pipe
3036 Driver Var(use_pipes)
3037
3038 print-file-name=
3039 Driver JoinedOrMissing Var(print_file_name)
3040
3041 print-libgcc-file-name
3042 Driver
3043
3044 print-multi-directory
3045 Driver Var(print_multi_directory)
3046
3047 print-multi-lib
3048 Driver Var(print_multi_lib)
3049
3050 print-multi-os-directory
3051 Driver Var(print_multi_os_directory)
3052
3053 print-multiarch
3054 Driver Var(print_multiarch)
3055
3056 print-prog-name=
3057 Driver JoinedOrMissing Var(print_prog_name)
3058
3059 print-search-dirs
3060 Driver Var(print_search_dirs)
3061
3062 print-sysroot
3063 Driver Var(print_sysroot)
3064
3065 print-sysroot-headers-suffix
3066 Driver Var(print_sysroot_headers_suffix)
3067
3068 quiet
3069 Common Var(quiet_flag) RejectDriver
3070 Do not display functions compiled or elapsed time.
3071
3072 r
3073 Driver
3074
3075 s
3076 Driver
3077
3078 save-temps
3079 Driver
3080
3081 save-temps=
3082 Driver Joined
3083
3084 t
3085 Driver
3086
3087 time
3088 Driver Var(report_times)
3089
3090 time=
3091 Driver JoinedOrMissing
3092
3093 u
3094 Driver Joined Separate
3095
3096 undef
3097 Driver
3098 ; C option, but driver must not handle as "-u ndef".
3099
3100 v
3101 Common Driver Var(verbose_flag)
3102 Enable verbose output.
3103
3104 version
3105 Common Var(version_flag) RejectDriver
3106 Display the compiler's version.
3107
3108 w
3109 Common Var(inhibit_warnings)
3110 Suppress warnings.
3111
3112 wrapper
3113 Driver Separate Var(wrapper_string)
3114
3115 x
3116 Driver Joined Separate
3117
3118 shared
3119 Driver RejectNegative Negative(static-pie)
3120 Create a shared library.
3121
3122 shared-libgcc
3123 Driver
3124
3125 specs
3126 Driver Separate Alias(specs=)
3127
3128 specs=
3129 Driver Joined
3130
3131 static
3132 Driver
3133
3134 static-libgcc
3135 Driver
3136
3137 static-libgfortran
3138 Driver
3139 ; Documented for Fortran, but always accepted by driver.
3140
3141 static-libstdc++
3142 Driver
3143
3144 static-libgo
3145 Driver
3146 ; Documented for Go, but always accepted by driver.
3147
3148 static-libasan
3149 Driver
3150
3151 static-libtsan
3152 Driver
3153
3154 static-liblsan
3155 Driver
3156
3157 static-libubsan
3158 Driver
3159
3160 symbolic
3161 Driver
3162
3163 no-pie
3164 Driver RejectNegative Negative(shared)
3165 Don't create a dynamically linked position independent executable.
3166
3167 pie
3168 Driver RejectNegative Negative(no-pie)
3169 Create a dynamically linked position independent executable.
3170
3171 static-pie
3172 Driver RejectNegative Negative(pie)
3173 Create a static position independent executable.
3174
3175 z
3176 Driver Joined Separate
3177
3178 fipa-ra
3179 Common Report Var(flag_ipa_ra) Optimization
3180 Use caller save register across calls if possible.
3181
3182 ; This comment is to ensure we retain the blank line above.