contrib/gcc-8.0/gcc/common.opt

   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) Optimization
 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) Optimization
 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) Optimization
 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) Optimization
 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 type of coverage sanitization.
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 -fdebug-prefix-map=<old>=<new> Map one directory name to another in debug information.
1179
1180 ffile-prefix-map=
1181 Common Joined RejectNegative Var(common_deferred_options) Defer
1182 -ffile-prefix-map=<old>=<new> Map one directory name to another in compilation result.
1183
1184 fdebug-types-section
1185 Common Report Var(flag_debug_types_section) Init(0)
1186 Output .debug_types section when using DWARF v4 debuginfo.
1187
1188 ; Nonzero for -fdefer-pop: don't pop args after each function call
1189 ; instead save them up to pop many calls' args with one insns.
1190 fdefer-pop
1191 Common Report Var(flag_defer_pop) Optimization
1192 Defer popping functions args from stack until later.
1193
1194 fdelayed-branch
1195 Common Report Var(flag_delayed_branch) Optimization
1196 Attempt to fill delay slots of branch instructions.
1197
1198 fdelete-dead-exceptions
1199 Common Report Var(flag_delete_dead_exceptions) Init(0) Optimization
1200 Delete dead instructions that may throw exceptions.
1201
1202 fdelete-null-pointer-checks
1203 Common Report Var(flag_delete_null_pointer_checks) Init(-1) Optimization
1204 Delete useless null pointer checks.
1205
1206 fdevirtualize-at-ltrans
1207 Common Report Var(flag_ltrans_devirtualize)
1208 Stream extra data to support more aggressive devirtualization in LTO local transformation mode.
1209
1210 fdevirtualize-speculatively
1211 Common Report Var(flag_devirtualize_speculatively) Optimization
1212 Perform speculative devirtualization.
1213
1214 fdevirtualize
1215 Common Report Var(flag_devirtualize) Optimization
1216 Try to convert virtual calls to direct ones.
1217
1218 fdiagnostics-show-location=
1219 Common Joined RejectNegative Enum(diagnostic_prefixing_rule)
1220 -fdiagnostics-show-location=[once|every-line]   How often to emit source location at the beginning of line-wrapped diagnostics.
1221
1222 ; Required for these enum values.
1223 SourceInclude
1224 pretty-print.h
1225
1226 Enum
1227 Name(diagnostic_prefixing_rule) Type(int)
1228
1229 EnumValue
1230 Enum(diagnostic_prefixing_rule) String(once) Value(DIAGNOSTICS_SHOW_PREFIX_ONCE)
1231
1232 EnumValue
1233 Enum(diagnostic_prefixing_rule) String(every-line) Value(DIAGNOSTICS_SHOW_PREFIX_EVERY_LINE)
1234
1235 fdiagnostics-show-caret
1236 Common Var(flag_diagnostics_show_caret) Init(1)
1237 Show the source line with a caret indicating the column.
1238
1239 fdiagnostics-color
1240 Common Alias(fdiagnostics-color=,always,never)
1241 ;
1242
1243 fdiagnostics-color=
1244 Driver Common Joined RejectNegative Var(flag_diagnostics_show_color) Enum(diagnostic_color_rule) Init(DIAGNOSTICS_COLOR_NO)
1245 -fdiagnostics-color=[never|always|auto] Colorize diagnostics.
1246
1247 ; Required for these enum values.
1248 SourceInclude
1249 diagnostic-color.h
1250
1251 Enum
1252 Name(diagnostic_color_rule) Type(int)
1253
1254 EnumValue
1255 Enum(diagnostic_color_rule) String(never) Value(DIAGNOSTICS_COLOR_NO)
1256
1257 EnumValue
1258 Enum(diagnostic_color_rule) String(always) Value(DIAGNOSTICS_COLOR_YES)
1259
1260 EnumValue
1261 Enum(diagnostic_color_rule) String(auto) Value(DIAGNOSTICS_COLOR_AUTO)
1262
1263 fdiagnostics-parseable-fixits
1264 Common Var(flag_diagnostics_parseable_fixits)
1265 Print fix-it hints in machine-readable form.
1266
1267 fdiagnostics-generate-patch
1268 Common Var(flag_diagnostics_generate_patch)
1269 Print fix-it hints to stderr in unified diff format.
1270
1271 fdiagnostics-show-option
1272 Common Var(flag_diagnostics_show_option) Init(1)
1273 Amend appropriate diagnostic messages with the command line option that controls them.
1274
1275 fdisable-
1276 Common Joined RejectNegative Var(common_deferred_options) Defer
1277 -fdisable-[tree|rtl|ipa]-<pass>=range1+range2 disables an optimization pass.
1278
1279 fenable-
1280 Common Joined RejectNegative Var(common_deferred_options) Defer
1281 -fenable-[tree|rtl|ipa]-<pass>=range1+range2 enables an optimization pass.
1282
1283 fdump-
1284 Common Joined RejectNegative Var(common_deferred_options) Defer
1285 -fdump-<type>   Dump various compiler internals to a file.
1286
1287 fdump-final-insns
1288 Driver RejectNegative
1289
1290 fdump-final-insns=
1291 Common RejectNegative Joined Var(flag_dump_final_insns)
1292 -fdump-final-insns=filename     Dump to filename the insns at the end of translation.
1293
1294 fdump-go-spec=
1295 Common RejectNegative Joined Var(flag_dump_go_spec)
1296 -fdump-go-spec=filename Write all declarations to file as Go code.
1297
1298 fdump-noaddr
1299 Common Report Var(flag_dump_noaddr)
1300 Suppress output of addresses in debugging dumps.
1301
1302 freport-bug
1303 Common Driver Var(flag_report_bug)
1304 Collect and dump debug information into temporary file if ICE in C/C++
1305 compiler occurred.
1306
1307 fdump-internal-locations
1308 Common Var(flag_dump_locations) Init(0)
1309 Dump detailed information on GCC's internal representation of source code locations.
1310
1311 fdump-passes
1312 Common Var(flag_dump_passes) Init(0)
1313 Dump optimization passes.
1314
1315 fdump-unnumbered
1316 Common Report Var(flag_dump_unnumbered)
1317 Suppress output of instruction numbers, line number notes and addresses in debugging dumps.
1318
1319 fdump-unnumbered-links
1320 Common Report Var(flag_dump_unnumbered_links)
1321 Suppress output of previous and next insn numbers in debugging dumps.
1322
1323 fdwarf2-cfi-asm
1324 Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
1325 Enable CFI tables via GAS assembler directives.
1326
1327 fearly-inlining
1328 Common Report Var(flag_early_inlining) Init(1) Optimization
1329 Perform early inlining.
1330
1331 feliminate-dwarf2-dups
1332 Common Ignore
1333 Does nothing.  Preserved for backward compatibility.
1334
1335 fipa-sra
1336 Common Report Var(flag_ipa_sra) Init(0) Optimization
1337 Perform interprocedural reduction of aggregates.
1338
1339 feliminate-unused-debug-symbols
1340 Common Report Var(flag_debug_only_used_symbols)
1341 Perform unused symbol elimination in debug info.
1342
1343 feliminate-unused-debug-types
1344 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
1345 Perform unused type elimination in debug info.
1346
1347 femit-class-debug-always
1348 Common Report Var(flag_emit_class_debug_always) Init(0)
1349 Do not suppress C++ class debug information.
1350
1351 fexceptions
1352 Common Report Var(flag_exceptions) Optimization
1353 Enable exception handling.
1354
1355 fexpensive-optimizations
1356 Common Report Var(flag_expensive_optimizations) Optimization
1357 Perform a number of minor, expensive optimizations.
1358
1359 fexcess-precision=
1360 Common Joined RejectNegative Enum(excess_precision) Var(flag_excess_precision_cmdline) Init(EXCESS_PRECISION_DEFAULT) SetByCombined
1361 -fexcess-precision=[fast|standard]      Specify handling of excess floating-point precision.
1362
1363 Enum
1364 Name(excess_precision) Type(enum excess_precision) UnknownError(unknown excess precision style %qs)
1365
1366 EnumValue
1367 Enum(excess_precision) String(fast) Value(EXCESS_PRECISION_FAST)
1368
1369 EnumValue
1370 Enum(excess_precision) String(standard) Value(EXCESS_PRECISION_STANDARD)
1371
1372 ; Whether we permit the extended set of values for FLT_EVAL_METHOD
1373 ; introduced in ISO/IEC TS 18661-3, or limit ourselves to those in C99/C11.
1374 fpermitted-flt-eval-methods=
1375 Common Joined RejectNegative Enum(permitted_flt_eval_methods) Var(flag_permitted_flt_eval_methods) Init(PERMITTED_FLT_EVAL_METHODS_DEFAULT)
1376 -fpermitted-flt-eval-methods=[c11|ts-18661]     Specify which values of FLT_EVAL_METHOD are permitted.
1377
1378 Enum
1379 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)
1380
1381 EnumValue
1382 Enum(permitted_flt_eval_methods) String(c11) Value(PERMITTED_FLT_EVAL_METHODS_C11)
1383
1384 EnumValue
1385 Enum(permitted_flt_eval_methods) String(ts-18661-3) Value(PERMITTED_FLT_EVAL_METHODS_TS_18661)
1386
1387 ffast-math
1388 Common Optimization
1389
1390 ffat-lto-objects
1391 Common Var(flag_fat_lto_objects)
1392 Output lto objects containing both the intermediate language and binary output.
1393
1394 ffinite-math-only
1395 Common Report Var(flag_finite_math_only) Optimization SetByCombined
1396 Assume no NaNs or infinities are generated.
1397
1398 ffixed-
1399 Common Joined RejectNegative Var(common_deferred_options) Defer
1400 -ffixed-<register>      Mark <register> as being unavailable to the compiler.
1401
1402 ffloat-store
1403 Common Report Var(flag_float_store) Optimization
1404 Don't allocate floats and doubles in extended-precision registers.
1405
1406 fforce-addr
1407 Common Ignore
1408 Does nothing.  Preserved for backward compatibility.
1409
1410 fforward-propagate
1411 Common Report Var(flag_forward_propagate) Optimization
1412 Perform a forward propagation pass on RTL.
1413
1414 ffp-contract=
1415 Common Joined RejectNegative Enum(fp_contract_mode) Var(flag_fp_contract_mode) Init(FP_CONTRACT_FAST) Optimization
1416 -ffp-contract=[off|on|fast]     Perform floating-point expression contraction.
1417
1418 Enum
1419 Name(fp_contract_mode) Type(enum fp_contract_mode) UnknownError(unknown floating point contraction style %qs)
1420
1421 EnumValue
1422 Enum(fp_contract_mode) String(off) Value(FP_CONTRACT_OFF)
1423
1424 ; Not implemented, fall back to conservative FP_CONTRACT_OFF.
1425 EnumValue
1426 Enum(fp_contract_mode) String(on) Value(FP_CONTRACT_OFF)
1427
1428 EnumValue
1429 Enum(fp_contract_mode) String(fast) Value(FP_CONTRACT_FAST)
1430
1431 ffp-int-builtin-inexact
1432 Common Report Var(flag_fp_int_builtin_inexact) Init(1) Optimization
1433 Allow built-in functions ceil, floor, round, trunc to raise \"inexact\" exceptions.
1434
1435 ; Nonzero means don't put addresses of constant functions in registers.
1436 ; Used for compiling the Unix kernel, where strange substitutions are
1437 ; done on the assembly output.
1438 ffunction-cse
1439 Common Report Var(flag_no_function_cse,0) Optimization
1440 Allow function addresses to be held in registers.
1441
1442 ffunction-sections
1443 Common Report Var(flag_function_sections)
1444 Place each function into its own section.
1445
1446 fgcse
1447 Common Report Var(flag_gcse) Optimization
1448 Perform global common subexpression elimination.
1449
1450 fgcse-lm
1451 Common Report Var(flag_gcse_lm) Init(1) Optimization
1452 Perform enhanced load motion during global common subexpression elimination.
1453
1454 fgcse-sm
1455 Common Report Var(flag_gcse_sm) Init(0) Optimization
1456 Perform store motion after global common subexpression elimination.
1457
1458 fgcse-las
1459 Common Report Var(flag_gcse_las) Init(0) Optimization
1460 Perform redundant load after store elimination in global common subexpression
1461 elimination.
1462
1463 fgcse-after-reload
1464 Common Report Var(flag_gcse_after_reload) Optimization
1465 Perform global common subexpression elimination after register allocation has
1466 finished.
1467
1468 Enum
1469 Name(dwarf_gnat_encodings) Type(int)
1470
1471 EnumValue
1472 Enum(dwarf_gnat_encodings) String(all) Value(DWARF_GNAT_ENCODINGS_ALL)
1473
1474 EnumValue
1475 Enum(dwarf_gnat_encodings) String(gdb) Value(DWARF_GNAT_ENCODINGS_GDB)
1476
1477 EnumValue
1478 Enum(dwarf_gnat_encodings) String(minimal) Value(DWARF_GNAT_ENCODINGS_MINIMAL)
1479
1480 fgnat-encodings=
1481 Common Enum(dwarf_gnat_encodings) Joined RejectNegative Report Undocumented Var(gnat_encodings)
1482 -fgnat-encodings=[all|gdb|minimal]      Select the balance between GNAT encodings and standard DWARF emitted in the debug information
1483
1484 ; This option is not documented yet as its semantics will change.
1485 fgraphite
1486 Common Report Var(flag_graphite) Optimization
1487 Enable in and out of Graphite representation.
1488
1489 fgraphite-identity
1490 Common Report Var(flag_graphite_identity) Optimization
1491 Enable Graphite Identity transformation.
1492
1493 fhoist-adjacent-loads
1494 Common Report Var(flag_hoist_adjacent_loads) Optimization
1495 Enable hoisting adjacent loads to encourage generating conditional move
1496 instructions.
1497
1498 fkeep-gc-roots-live
1499 Common Undocumented Report Var(flag_keep_gc_roots_live) Optimization
1500 ; Always keep a pointer to a live memory block
1501
1502 floop-parallelize-all
1503 Common Report Var(flag_loop_parallelize_all) Optimization
1504 Mark all loops as parallel.
1505
1506 floop-strip-mine
1507 Common Alias(floop-nest-optimize)
1508 Enable loop nest transforms.  Same as -floop-nest-optimize.
1509
1510 floop-interchange
1511 Common Report Var(flag_loop_interchange) Optimization
1512 Enable loop interchange on trees.
1513
1514 floop-block
1515 Common Alias(floop-nest-optimize)
1516 Enable loop nest transforms.  Same as -floop-nest-optimize.
1517
1518 floop-unroll-and-jam
1519 Common Report Var(flag_unroll_jam) Optimization
1520 Perform unroll-and-jam on loops.
1521
1522 fgnu-tm
1523 Common Report Var(flag_tm)
1524 Enable support for GNU transactional memory.
1525
1526 fgnu-unique
1527 Common Report Var(flag_gnu_unique) Init(1)
1528 Use STB_GNU_UNIQUE if supported by the assembler.
1529
1530 floop-flatten
1531 Common Ignore
1532 Does nothing. Preserved for backward compatibility.
1533
1534 floop-nest-optimize
1535 Common Report Var(flag_loop_nest_optimize) Optimization
1536 Enable the loop nest optimizer.
1537
1538 fstrict-volatile-bitfields
1539 Common Report Var(flag_strict_volatile_bitfields) Init(-1) Optimization
1540 Force bitfield accesses to match their type width.
1541
1542 fstore-merging
1543 Common Report Var(flag_store_merging) Optimization
1544 Merge adjacent stores.
1545
1546 fguess-branch-probability
1547 Common Report Var(flag_guess_branch_prob) Optimization
1548 Enable guessing of branch probabilities.
1549
1550 ; Nonzero means ignore `#ident' directives.  0 means handle them.
1551 ; Generate position-independent code for executables if possible
1552 ; On SVR4 targets, it also controls whether or not to emit a
1553 ; string identifying the compiler.
1554 fident
1555 Common Report Var(flag_no_ident,0)
1556 Process #ident directives.
1557
1558 fif-conversion
1559 Common Report Var(flag_if_conversion) Optimization
1560 Perform conversion of conditional jumps to branchless equivalents.
1561
1562 fif-conversion2
1563 Common Report Var(flag_if_conversion2) Optimization
1564 Perform conversion of conditional jumps to conditional execution.
1565
1566 fstack-reuse=
1567 Common Joined RejectNegative Enum(stack_reuse_level) Var(flag_stack_reuse) Init(SR_ALL) Optimization
1568 -fstack-reuse=[all|named_vars|none]     Set stack reuse level for local variables.
1569
1570 Enum
1571 Name(stack_reuse_level) Type(enum stack_reuse_level) UnknownError(unknown Stack Reuse Level %qs)
1572
1573 EnumValue
1574 Enum(stack_reuse_level) String(all) Value(SR_ALL)
1575
1576 EnumValue
1577 Enum(stack_reuse_level) String(named_vars) Value(SR_NAMED_VARS)
1578
1579 EnumValue
1580 Enum(stack_reuse_level) String(none) Value(SR_NONE)
1581
1582 ftree-loop-if-convert
1583 Common Report Var(flag_tree_loop_if_convert) Init(-1) Optimization
1584 Convert conditional jumps in innermost loops to branchless equivalents.
1585
1586 ftree-loop-if-convert-stores
1587 Common Ignore
1588 Does nothing. Preserved for backward compatibility.
1589
1590 ; -finhibit-size-directive inhibits output of .size for ELF.
1591 ; This is used only for compiling crtstuff.c,
1592 ; and it may be extended to other effects
1593 ; needed for crtstuff.c on other systems.
1594 finhibit-size-directive
1595 Common Report Var(flag_inhibit_size_directive)
1596 Do not generate .size directives.
1597
1598 findirect-inlining
1599 Common Report Var(flag_indirect_inlining) Optimization
1600 Perform indirect inlining.
1601
1602 ; General flag to enable inlining.  Specifying -fno-inline will disable
1603 ; all inlining apart from always-inline functions.
1604 finline
1605 Common Report Var(flag_no_inline,0) Init(0) Optimization
1606 Enable inlining of function declared \"inline\", disabling disables all inlining.
1607
1608 finline-small-functions
1609 Common Report Var(flag_inline_small_functions) Optimization
1610 Integrate functions into their callers when code size is known not to grow.
1611
1612 finline-functions
1613 Common Report Var(flag_inline_functions) Optimization
1614 Integrate functions not declared \"inline\" into their callers when profitable.
1615
1616 finline-functions-called-once
1617 Common Report Var(flag_inline_functions_called_once) Optimization
1618 Integrate functions only required by their single caller.
1619
1620 finline-limit-
1621 Common RejectNegative Joined Alias(finline-limit=)
1622
1623 finline-limit=
1624 Common RejectNegative Joined UInteger
1625 -finline-limit=<number> Limit the size of inlined functions to <number>.
1626
1627 finline-atomics
1628 Common Report Var(flag_inline_atomics) Init(1) Optimization
1629 Inline __atomic operations when a lock free instruction sequence is available.
1630
1631 fcf-protection
1632 Common RejectNegative Alias(fcf-protection=,full)
1633
1634 fcf-protection=
1635 Common Report Joined RejectNegative Enum(cf_protection_level) Var(flag_cf_protection) Init(CF_NONE)
1636 -fcf-protection=[full|branch|return|none]       Instrument functions with checks to verify jump/call/return control-flow transfer
1637 instructions have valid targets.
1638
1639 Enum
1640 Name(cf_protection_level) Type(enum cf_protection_level) UnknownError(unknown Control-Flow Protection Level %qs)
1641
1642 EnumValue
1643 Enum(cf_protection_level) String(full) Value(CF_FULL)
1644
1645 EnumValue
1646 Enum(cf_protection_level) String(branch) Value(CF_BRANCH)
1647
1648 EnumValue
1649 Enum(cf_protection_level) String(return) Value(CF_RETURN)
1650
1651 EnumValue
1652 Enum(cf_protection_level) String(none) Value(CF_NONE)
1653
1654 finstrument-functions
1655 Common Report Var(flag_instrument_function_entry_exit)
1656 Instrument function entry and exit with profiling calls.
1657
1658 finstrument-functions-exclude-function-list=
1659 Common RejectNegative Joined
1660 -finstrument-functions-exclude-function-list=name,...  Do not instrument listed functions.
1661
1662 finstrument-functions-exclude-file-list=
1663 Common RejectNegative Joined
1664 -finstrument-functions-exclude-file-list=filename,...  Do not instrument functions listed in files.
1665
1666 fipa-cp
1667 Common Report Var(flag_ipa_cp) Optimization
1668 Perform interprocedural constant propagation.
1669
1670 fipa-cp-clone
1671 Common Report Var(flag_ipa_cp_clone) Optimization
1672 Perform cloning to make Interprocedural constant propagation stronger.
1673
1674 fipa-cp-alignment
1675 Common Ignore
1676 Does nothing.  Preserved for backward compatibility.
1677
1678 fipa-bit-cp
1679 Common Report Var(flag_ipa_bit_cp) Optimization
1680 Perform interprocedural bitwise constant propagation.
1681
1682 fipa-profile
1683 Common Report Var(flag_ipa_profile) Init(0) Optimization
1684 Perform interprocedural profile propagation.
1685
1686 fipa-pta
1687 Common Report Var(flag_ipa_pta) Init(0) Optimization
1688 Perform interprocedural points-to analysis.
1689
1690 fipa-pure-const
1691 Common Report Var(flag_ipa_pure_const) Init(0) Optimization
1692 Discover pure and const functions.
1693
1694 fipa-icf
1695 Common Report Var(flag_ipa_icf) Optimization
1696 Perform Identical Code Folding for functions and read-only variables.
1697
1698 fipa-icf-functions
1699 Common Report Var(flag_ipa_icf_functions) Optimization
1700 Perform Identical Code Folding for functions.
1701
1702 fipa-icf-variables
1703 Common Report Var(flag_ipa_icf_variables) Optimization
1704 Perform Identical Code Folding for variables.
1705
1706 fipa-reference
1707 Common Report Var(flag_ipa_reference) Init(0) Optimization
1708 Discover readonly and non addressable static variables.
1709
1710 fipa-matrix-reorg
1711 Common Ignore
1712 Does nothing. Preserved for backward compatibility.
1713
1714 fipa-struct-reorg
1715 Common Ignore
1716 Does nothing. Preserved for backward compatibility.
1717
1718 fipa-vrp
1719 Common Report Var(flag_ipa_vrp) Optimization
1720 Perform IPA Value Range Propagation.
1721
1722 fira-algorithm=
1723 Common Joined RejectNegative Enum(ira_algorithm) Var(flag_ira_algorithm) Init(IRA_ALGORITHM_CB) Optimization
1724 -fira-algorithm=[CB|priority]   Set the used IRA algorithm.
1725
1726 Enum
1727 Name(ira_algorithm) Type(enum ira_algorithm) UnknownError(unknown IRA algorithm %qs)
1728
1729 EnumValue
1730 Enum(ira_algorithm) String(CB) Value(IRA_ALGORITHM_CB)
1731
1732 EnumValue
1733 Enum(ira_algorithm) String(priority) Value(IRA_ALGORITHM_PRIORITY)
1734
1735 fira-region=
1736 Common Joined RejectNegative Enum(ira_region) Var(flag_ira_region) Init(IRA_REGION_AUTODETECT) Optimization
1737 -fira-region=[one|all|mixed]    Set regions for IRA.
1738
1739 Enum
1740 Name(ira_region) Type(enum ira_region) UnknownError(unknown IRA region %qs)
1741
1742 EnumValue
1743 Enum(ira_region) String(one) Value(IRA_REGION_ONE)
1744
1745 EnumValue
1746 Enum(ira_region) String(all) Value(IRA_REGION_ALL)
1747
1748 EnumValue
1749 Enum(ira_region) String(mixed) Value(IRA_REGION_MIXED)
1750
1751 fira-hoist-pressure
1752 Common Report Var(flag_ira_hoist_pressure) Init(1) Optimization
1753 Use IRA based register pressure calculation
1754 in RTL hoist optimizations.
1755
1756 fira-loop-pressure
1757 Common Report Var(flag_ira_loop_pressure) Optimization
1758 Use IRA based register pressure calculation
1759 in RTL loop optimizations.
1760
1761 fira-share-save-slots
1762 Common Report Var(flag_ira_share_save_slots) Init(1) Optimization
1763 Share slots for saving different hard registers.
1764
1765 fira-share-spill-slots
1766 Common Report Var(flag_ira_share_spill_slots) Init(1) Optimization
1767 Share stack slots for spilled pseudo-registers.
1768
1769 fira-verbose=
1770 Common RejectNegative Joined UInteger Var(flag_ira_verbose) Init(5)
1771 -fira-verbose=<number>  Control IRA's level of diagnostic messages.
1772
1773 fivopts
1774 Common Report Var(flag_ivopts) Init(1) Optimization
1775 Optimize induction variables on trees.
1776
1777 fjump-tables
1778 Common Var(flag_jump_tables) Init(1) Optimization
1779 Use jump tables for sufficiently large switch statements.
1780
1781 fkeep-inline-functions
1782 Common Report Var(flag_keep_inline_functions)
1783 Generate code for functions even if they are fully inlined.
1784
1785 fkeep-static-functions
1786 Common Report Var(flag_keep_static_functions)
1787 Generate code for static functions even if they are never called.
1788
1789 fkeep-static-consts
1790 Common Report Var(flag_keep_static_consts) Init(1)
1791 Emit static const variables even if they are not used.
1792
1793 fleading-underscore
1794 Common Report Var(flag_leading_underscore) Init(-1)
1795 Give external symbols a leading underscore.
1796
1797 floop-optimize
1798 Common Ignore
1799 Does nothing.  Preserved for backward compatibility.
1800
1801 flra-remat
1802 Common Report Var(flag_lra_remat) Optimization
1803 Do CFG-sensitive rematerialization in LRA.
1804
1805 flto
1806 Common
1807 Enable link-time optimization.
1808
1809 flto=
1810 Common RejectNegative Joined Var(flag_lto)
1811 Link-time optimization with number of parallel jobs or jobserver.
1812
1813 Enum
1814 Name(lto_partition_model) Type(enum lto_partition_model) UnknownError(unknown LTO partitioning model %qs)
1815
1816 EnumValue
1817 Enum(lto_partition_model) String(none) Value(LTO_PARTITION_NONE)
1818
1819 EnumValue
1820 Enum(lto_partition_model) String(one) Value(LTO_PARTITION_ONE)
1821
1822 EnumValue
1823 Enum(lto_partition_model) String(balanced) Value(LTO_PARTITION_BALANCED)
1824
1825 EnumValue
1826 Enum(lto_partition_model) String(1to1) Value(LTO_PARTITION_1TO1)
1827
1828 EnumValue
1829 Enum(lto_partition_model) String(max) Value(LTO_PARTITION_MAX)
1830
1831 flto-partition=
1832 Common Joined RejectNegative Enum(lto_partition_model) Var(flag_lto_partition) Init(LTO_PARTITION_BALANCED)
1833 Specify the algorithm to partition symbols and vars at linktime.
1834
1835 ; The initial value of -1 comes from Z_DEFAULT_COMPRESSION in zlib.h.
1836 flto-compression-level=
1837 Common Joined RejectNegative UInteger Var(flag_lto_compression_level) Init(-1) IntegerRange(0, 9)
1838 -flto-compression-level=<number>        Use zlib compression level <number> for IL.
1839
1840 flto-odr-type-merging
1841 Common Report Var(flag_lto_odr_type_mering) Init(1)
1842 Merge C++ types using One Definition Rule.
1843
1844 flto-report
1845 Common Report Var(flag_lto_report) Init(0)
1846 Report various link-time optimization statistics.
1847
1848 flto-report-wpa
1849 Common Report Var(flag_lto_report_wpa) Init(0)
1850 Report various link-time optimization statistics for WPA only.
1851
1852 fmath-errno
1853 Common Report Var(flag_errno_math) Init(1) Optimization SetByCombined
1854 Set errno after built-in math functions.
1855
1856 fmax-errors=
1857 Common Joined RejectNegative UInteger Var(flag_max_errors)
1858 -fmax-errors=<number>   Maximum number of errors to report.
1859
1860 fmem-report
1861 Common Report Var(mem_report)
1862 Report on permanent memory allocation.
1863
1864 fmem-report-wpa
1865 Common Report Var(mem_report_wpa)
1866 Report on permanent memory allocation in WPA only.
1867
1868 ; This will attempt to merge constant section constants, if 1 only
1869 ; string constants and constants from constant pool, if 2 also constant
1870 ; variables.
1871 fmerge-all-constants
1872 Common Report Var(flag_merge_constants,2) Init(1)
1873 Attempt to merge identical constants and constant variables.
1874
1875 fmerge-constants
1876 Common Report Var(flag_merge_constants,1)
1877 Attempt to merge identical constants across compilation units.
1878
1879 fmerge-debug-strings
1880 Common Report Var(flag_merge_debug_strings) Init(1)
1881 Attempt to merge identical debug strings across compilation units.
1882
1883 fmessage-length=
1884 Common RejectNegative Joined UInteger
1885 -fmessage-length=<number>       Limit diagnostics to <number> characters per line.  0 suppresses line-wrapping.
1886
1887 fmodulo-sched
1888 Common Report Var(flag_modulo_sched) Optimization
1889 Perform SMS based modulo scheduling before the first scheduling pass.
1890
1891 fmodulo-sched-allow-regmoves
1892 Common Report Var(flag_modulo_sched_allow_regmoves) Optimization
1893 Perform SMS based modulo scheduling with register moves allowed.
1894
1895 fmove-loop-invariants
1896 Common Report Var(flag_move_loop_invariants) Optimization
1897 Move loop invariant computations out of loops.
1898
1899 fdce
1900 Common Var(flag_dce) Init(1) Optimization
1901 Use the RTL dead code elimination pass.
1902
1903 fdse
1904 Common Var(flag_dse) Init(1) Optimization
1905 Use the RTL dead store elimination pass.
1906
1907 freschedule-modulo-scheduled-loops
1908 Common Report Var(flag_resched_modulo_sched) Optimization
1909 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling.
1910
1911 fnon-call-exceptions
1912 Common Report Var(flag_non_call_exceptions) Optimization
1913 Support synchronous non-call exceptions.
1914
1915 foffload=
1916 Common Driver Joined MissingArgError(options or targets missing after %qs)
1917 -foffload=<targets>=<options>  Specify offloading targets and options for them.
1918
1919 foffload-abi=
1920 Common Joined RejectNegative Enum(offload_abi) Var(flag_offload_abi) Init(OFFLOAD_ABI_UNSET)
1921 -foffload-abi=[lp64|ilp32]     Set the ABI to use in an offload compiler.
1922
1923 Enum
1924 Name(offload_abi) Type(enum offload_abi) UnknownError(unknown offload ABI %qs)
1925
1926 EnumValue
1927 Enum(offload_abi) String(ilp32) Value(OFFLOAD_ABI_ILP32)
1928
1929 EnumValue
1930 Enum(offload_abi) String(lp64) Value(OFFLOAD_ABI_LP64)
1931
1932 fomit-frame-pointer
1933 Common Report Var(flag_omit_frame_pointer) Optimization
1934 When possible do not generate stack frames.
1935
1936 fopt-info
1937 Common Report Var(flag_opt_info) Optimization
1938 Enable all optimization info dumps on stderr.
1939
1940 fopt-info-
1941 Common Joined RejectNegative Var(common_deferred_options) Defer
1942 -fopt-info[-<type>=filename]    Dump compiler optimization details.
1943
1944 foptimize-register-move
1945 Common Ignore
1946 Does nothing. Preserved for backward compatibility.
1947
1948 foptimize-sibling-calls
1949 Common Report Var(flag_optimize_sibling_calls) Optimization
1950 Optimize sibling and tail recursive calls.
1951
1952 fpartial-inlining
1953 Common Report Var(flag_partial_inlining) Optimization
1954 Perform partial inlining.
1955
1956 fpre-ipa-mem-report
1957 Common Report Var(pre_ipa_mem_report)
1958 Report on memory allocation before interprocedural optimization.
1959
1960 fpost-ipa-mem-report
1961 Common Report Var(post_ipa_mem_report)
1962 Report on memory allocation before interprocedural optimization.
1963
1964 fpack-struct
1965 Common Report Var(flag_pack_struct) Optimization
1966 Pack structure members together without holes.
1967
1968 fpack-struct=
1969 Common RejectNegative Joined UInteger Optimization
1970 -fpack-struct=<number>  Set initial maximum structure member alignment.
1971
1972 fpcc-struct-return
1973 Common Report Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN)
1974 Return small aggregates in memory, not registers.
1975
1976 fpeel-loops
1977 Common Report Var(flag_peel_loops) Optimization
1978 Perform loop peeling.
1979
1980 fpeephole
1981 Common Report Var(flag_no_peephole,0) Optimization
1982 Enable machine specific peephole optimizations.
1983
1984 fpeephole2
1985 Common Report Var(flag_peephole2) Optimization
1986 Enable an RTL peephole pass before sched2.
1987
1988 fPIC
1989 Common Report Var(flag_pic,2) Negative(fPIE) Init(-1)
1990 Generate position-independent code if possible (large mode).
1991
1992 fPIE
1993 Common Report Var(flag_pie,2) Negative(fpic) Init(-1)
1994 Generate position-independent code for executables if possible (large mode).
1995
1996 fpic
1997 Common Report Var(flag_pic,1) Negative(fpie) Init(-1)
1998 Generate position-independent code if possible (small mode).
1999
2000 fpie
2001 Common Report Var(flag_pie,1) Negative(fPIC) Init(-1)
2002 Generate position-independent code for executables if possible (small mode).
2003
2004 fplt
2005 Common Report Var(flag_plt) Init(1) Optimization
2006 Use PLT for PIC calls (-fno-plt: load the address from GOT at call site).
2007
2008 fplugin=
2009 Common Joined RejectNegative Var(common_deferred_options) Defer
2010 Specify a plugin to load.
2011
2012 fplugin-arg-
2013 Common Joined RejectNegative Var(common_deferred_options) Defer
2014 -fplugin-arg-<name>-<key>[=<value>]     Specify argument <key>=<value> for plugin <name>.
2015
2016 fpredictive-commoning
2017 Common Report Var(flag_predictive_commoning) Optimization
2018 Run predictive commoning optimization.
2019
2020 fprefetch-loop-arrays
2021 Common Report Var(flag_prefetch_loop_arrays) Init(-1) Optimization
2022 Generate prefetch instructions, if available, for arrays in loops.
2023
2024 fprofile
2025 Common Report Var(profile_flag)
2026 Enable basic program profiling code.
2027
2028 fprofile-abs-path
2029 Common Report Var(profile_abs_path_flag)
2030 Generate absolute source path names for gcov.
2031
2032 fprofile-arcs
2033 Common Report Var(profile_arc_flag)
2034 Insert arc-based program profiling code.
2035
2036 fprofile-dir=
2037 Common Joined RejectNegative Var(profile_data_prefix)
2038 Set the top-level directory for storing the profile data.
2039 The default is 'pwd'.
2040
2041 fprofile-correction
2042 Common Report Var(flag_profile_correction)
2043 Enable correction of flow inconsistent profile data input.
2044
2045 fprofile-update=
2046 Common Joined RejectNegative Enum(profile_update) Var(flag_profile_update) Init(PROFILE_UPDATE_SINGLE)
2047 -fprofile-update=[single|atomic|prefer-atomic]  Set the profile update method.
2048
2049 Enum
2050 Name(profile_update) Type(enum profile_update) UnknownError(unknown profile update method %qs)
2051
2052 EnumValue
2053 Enum(profile_update) String(single) Value(PROFILE_UPDATE_SINGLE)
2054
2055 EnumValue
2056 Enum(profile_update) String(atomic) Value(PROFILE_UPDATE_ATOMIC)
2057
2058 EnumValue
2059 Enum(profile_update) String(prefer-atomic) Value(PROFILE_UPDATE_PREFER_ATOMIC)
2060
2061 fprofile-generate
2062 Common
2063 Enable common options for generating profile info for profile feedback directed optimizations.
2064
2065 fprofile-generate=
2066 Common Joined RejectNegative
2067 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=.
2068
2069 fprofile-use
2070 Common Var(flag_profile_use)
2071 Enable common options for performing profile feedback directed optimizations.
2072
2073 fprofile-use=
2074 Common Joined RejectNegative
2075 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=.
2076
2077 fprofile-values
2078 Common Report Var(flag_profile_values)
2079 Insert code to profile values of expressions.
2080
2081 fprofile-report
2082 Common Report Var(profile_report)
2083 Report on consistency of profile.
2084
2085 fprofile-reorder-functions
2086 Common Report Var(flag_profile_reorder_functions)
2087 Enable function reordering that improves code placement.
2088
2089 fpatchable-function-entry=
2090 Common Joined Optimization
2091 Insert NOP instructions at each function entry.
2092
2093 frandom-seed
2094 Common Var(common_deferred_options) Defer
2095
2096 frandom-seed=
2097 Common Joined RejectNegative Var(common_deferred_options) Defer
2098 -frandom-seed=<string>  Make compile reproducible using <string>.
2099
2100 ; This switch causes the command line that was used to create an
2101 ; object file to be recorded into the object file.  The exact format
2102 ; of this recording is target and binary file format dependent.
2103 ; It is related to the -fverbose-asm switch, but that switch only
2104 ; records information in the assembler output file as comments, so
2105 ; they never reach the object file.
2106 frecord-gcc-switches
2107 Common Report Var(flag_record_gcc_switches)
2108 Record gcc command line switches in the object file.
2109
2110 freg-struct-return
2111 Common Report Var(flag_pcc_struct_return,0) Optimization
2112 Return small aggregates in registers.
2113
2114 fregmove
2115 Common Ignore
2116 Does nothing. Preserved for backward compatibility.
2117
2118 flifetime-dse
2119 Common Report Var(flag_lifetime_dse,2) Init(2) Optimization
2120 Tell DSE that the storage for a C++ object is dead when the constructor
2121 starts and when the destructor finishes.
2122
2123 flifetime-dse=
2124 Common Joined RejectNegative UInteger Var(flag_lifetime_dse) Optimization IntegerRange(0, 2)
2125
2126 flive-range-shrinkage
2127 Common Report Var(flag_live_range_shrinkage) Init(0) Optimization
2128 Relief of register pressure through live range shrinkage.
2129
2130 frename-registers
2131 Common Report Var(flag_rename_registers) Init(2) Optimization
2132 Perform a register renaming optimization pass.
2133
2134 fschedule-fusion
2135 Common Report Var(flag_schedule_fusion) Init(2) Optimization
2136 Perform a target dependent instruction fusion optimization pass.
2137
2138 freorder-blocks
2139 Common Report Var(flag_reorder_blocks) Optimization
2140 Reorder basic blocks to improve code placement.
2141
2142 freorder-blocks-algorithm=
2143 Common Joined RejectNegative Enum(reorder_blocks_algorithm) Var(flag_reorder_blocks_algorithm) Init(REORDER_BLOCKS_ALGORITHM_SIMPLE) Optimization
2144 -freorder-blocks-algorithm=[simple|stc] Set the used basic block reordering algorithm.
2145
2146 Enum
2147 Name(reorder_blocks_algorithm) Type(enum reorder_blocks_algorithm) UnknownError(unknown basic block reordering algorithm %qs)
2148
2149 EnumValue
2150 Enum(reorder_blocks_algorithm) String(simple) Value(REORDER_BLOCKS_ALGORITHM_SIMPLE)
2151
2152 EnumValue
2153 Enum(reorder_blocks_algorithm) String(stc) Value(REORDER_BLOCKS_ALGORITHM_STC)
2154
2155 freorder-blocks-and-partition
2156 Common Report Var(flag_reorder_blocks_and_partition) Optimization
2157 Reorder basic blocks and partition into hot and cold sections.
2158
2159 freorder-functions
2160 Common Report Var(flag_reorder_functions) Optimization
2161 Reorder functions to improve code placement.
2162
2163 frerun-cse-after-loop
2164 Common Report Var(flag_rerun_cse_after_loop) Optimization
2165 Add a common subexpression elimination pass after loop optimizations.
2166
2167 frerun-loop-opt
2168 Common Ignore
2169 Does nothing.  Preserved for backward compatibility.
2170
2171 frounding-math
2172 Common Report Var(flag_rounding_math) Optimization SetByCombined
2173 Disable optimizations that assume default FP rounding behavior.
2174
2175 fsched-interblock
2176 Common Report Var(flag_schedule_interblock) Init(1) Optimization
2177 Enable scheduling across basic blocks.
2178
2179 fsched-pressure
2180 Common Report Var(flag_sched_pressure) Init(0) Optimization
2181 Enable register pressure sensitive insn scheduling.
2182
2183 fsched-spec
2184 Common Report Var(flag_schedule_speculative) Init(1) Optimization
2185 Allow speculative motion of non-loads.
2186
2187 fsched-spec-load
2188 Common Report Var(flag_schedule_speculative_load) Optimization
2189 Allow speculative motion of some loads.
2190
2191 fsched-spec-load-dangerous
2192 Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
2193 Allow speculative motion of more loads.
2194
2195 fsched-verbose=
2196 Common RejectNegative Joined UInteger Var(sched_verbose_param) Init(1)
2197 -fsched-verbose=<number>        Set the verbosity level of the scheduler.
2198
2199 fsched2-use-superblocks
2200 Common Report Var(flag_sched2_use_superblocks) Optimization
2201 If scheduling post reload, do superblock scheduling.
2202
2203 fsched2-use-traces
2204 Common Ignore
2205 Does nothing.  Preserved for backward compatibility.
2206
2207 fschedule-insns
2208 Common Report Var(flag_schedule_insns) Optimization
2209 Reschedule instructions before register allocation.
2210
2211 fschedule-insns2
2212 Common Report Var(flag_schedule_insns_after_reload) Optimization
2213 Reschedule instructions after register allocation.
2214
2215 ; This flag should be on when a target implements non-trivial
2216 ; scheduling hooks, maybe saving some information for its own sake.
2217 ; On IA64, for example, this is used for correct bundling.
2218 fselective-scheduling
2219 Common Report Var(flag_selective_scheduling) Optimization
2220 Schedule instructions using selective scheduling algorithm.
2221
2222 fselective-scheduling2
2223 Common Report Var(flag_selective_scheduling2) Optimization
2224 Run selective scheduling after reload.
2225
2226 fself-test=
2227 Common Undocumented Joined Var(flag_self_test)
2228 Run self-tests, using the given path to locate test files.
2229
2230 fsel-sched-pipelining
2231 Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization
2232 Perform software pipelining of inner loops during selective scheduling.
2233
2234 fsel-sched-pipelining-outer-loops
2235 Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
2236 Perform software pipelining of outer loops during selective scheduling.
2237
2238 fsel-sched-reschedule-pipelined
2239 Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
2240 Reschedule pipelined regions without pipelining.
2241
2242 fsemantic-interposition
2243 Common Report Var(flag_semantic_interposition) Init(1)
2244 Allow interposing function (or variables) by ones with different semantics (or initializer) respectively by dynamic linker.
2245
2246 ; sched_stalled_insns means that insns can be moved prematurely from the queue
2247 ; of stalled insns into the ready list.
2248 fsched-stalled-insns
2249 Common Report Var(flag_sched_stalled_insns) Optimization UInteger
2250 Allow premature scheduling of queued insns.
2251
2252 fsched-stalled-insns=
2253 Common RejectNegative Joined UInteger Optimization
2254 -fsched-stalled-insns=<number>  Set number of queued insns that can be prematurely scheduled.
2255
2256 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
2257 ; be examined for a dependency on a stalled insn that is candidate for
2258 ; premature removal from the queue of stalled insns into the ready list (has
2259 ; an effect only if the flag 'sched_stalled_insns' is set).
2260 fsched-stalled-insns-dep
2261 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
2262 Set dependence distance checking in premature scheduling of queued insns.
2263
2264 fsched-stalled-insns-dep=
2265 Common RejectNegative Joined UInteger Optimization
2266 -fsched-stalled-insns-dep=<number>      Set dependence distance checking in premature scheduling of queued insns.
2267
2268 fsched-group-heuristic
2269 Common Report Var(flag_sched_group_heuristic) Init(1) Optimization
2270 Enable the group heuristic in the scheduler.
2271
2272 fsched-critical-path-heuristic
2273 Common Report Var(flag_sched_critical_path_heuristic) Init(1) Optimization
2274 Enable the critical path heuristic in the scheduler.
2275
2276 fsched-spec-insn-heuristic
2277 Common Report Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
2278 Enable the speculative instruction heuristic in the scheduler.
2279
2280 fsched-rank-heuristic
2281 Common Report Var(flag_sched_rank_heuristic) Init(1) Optimization
2282 Enable the rank heuristic in the scheduler.
2283
2284 fsched-last-insn-heuristic
2285 Common Report Var(flag_sched_last_insn_heuristic) Init(1) Optimization
2286 Enable the last instruction heuristic in the scheduler.
2287
2288 fsched-dep-count-heuristic
2289 Common Report Var(flag_sched_dep_count_heuristic) Init(1) Optimization
2290 Enable the dependent count heuristic in the scheduler.
2291
2292 fsection-anchors
2293 Common Report Var(flag_section_anchors) Optimization
2294 Access data in the same section from shared anchor points.
2295
2296 fsee
2297 Common Ignore
2298 Does nothing.  Preserved for backward compatibility.
2299
2300 fzee
2301 Common Ignore
2302 Does nothing.  Preserved for backward compatibility.
2303
2304 free
2305 Common Report Var(flag_ree) Init(0)
2306 Turn on Redundant Extensions Elimination pass.
2307
2308 fshow-column
2309 Common Report Var(flag_show_column) Init(1)
2310 Show column numbers in diagnostics, when available.  Default on.
2311
2312 fshrink-wrap
2313 Common Report Var(flag_shrink_wrap) Optimization
2314 Emit function prologues only before parts of the function that need it,
2315 rather than at the top of the function.
2316
2317 fshrink-wrap-separate
2318 Common Report Var(flag_shrink_wrap_separate) Init(1) Optimization
2319 Shrink-wrap parts of the prologue and epilogue separately.
2320
2321 fsignaling-nans
2322 Common Report Var(flag_signaling_nans) Optimization SetByCombined
2323 Disable optimizations observable by IEEE signaling NaNs.
2324
2325 fsigned-zeros
2326 Common Report Var(flag_signed_zeros) Init(1) Optimization SetByCombined
2327 Disable floating point optimizations that ignore the IEEE signedness of zero.
2328
2329 fsingle-precision-constant
2330 Common Report Var(flag_single_precision_constant) Optimization
2331 Convert floating point constants to single precision constants.
2332
2333 fsplit-ivs-in-unroller
2334 Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
2335 Split lifetimes of induction variables when loops are unrolled.
2336
2337 fsplit-stack
2338 Common Report Var(flag_split_stack) Init(-1)
2339 Generate discontiguous stack frames.
2340
2341 fsplit-wide-types
2342 Common Report Var(flag_split_wide_types) Optimization
2343 Split wide types into independent registers.
2344
2345 fssa-backprop
2346 Common Report Var(flag_ssa_backprop) Init(1) Optimization
2347 Enable backward propagation of use properties at the SSA level.
2348
2349 fssa-phiopt
2350 Common Report Var(flag_ssa_phiopt) Optimization
2351 Optimize conditional patterns using SSA PHI nodes.
2352
2353 fstdarg-opt
2354 Common Report Var(flag_stdarg_opt) Init(1) Optimization
2355 Optimize amount of stdarg registers saved to stack at start of function.
2356
2357 fvariable-expansion-in-unroller
2358 Common Report Var(flag_variable_expansion_in_unroller) Optimization
2359 Apply variable expansion when loops are unrolled.
2360
2361 fstack-check=
2362 Common Report RejectNegative Joined Optimization
2363 -fstack-check=[no|generic|specific]     Insert stack checking code into the program.
2364
2365 fstack-check
2366 Common Alias(fstack-check=, specific, no)
2367 Insert stack checking code into the program.  Same as -fstack-check=specific.
2368
2369 fstack-clash-protection
2370 Common Report Var(flag_stack_clash_protection) Optimization
2371 Insert code to probe each page of stack space as it is allocated to protect
2372 from stack-clash style attacks.
2373
2374 fstack-limit
2375 Common Var(common_deferred_options) Defer
2376
2377 fstack-limit-register=
2378 Common RejectNegative Joined Var(common_deferred_options) Defer
2379 -fstack-limit-register=<register>       Trap if the stack goes past <register>.
2380
2381 fstack-limit-symbol=
2382 Common RejectNegative Joined Var(common_deferred_options) Defer
2383 -fstack-limit-symbol=<name>     Trap if the stack goes past symbol <name>.
2384
2385 fstack-protector
2386 Common Report Var(flag_stack_protect, 1) Init(-1) Optimization
2387 Use propolice as a stack protection method.
2388
2389 fstack-protector-all
2390 Common Report RejectNegative Var(flag_stack_protect, 2) Init(-1) Optimization
2391 Use a stack protection method for every function.
2392
2393 fstack-protector-strong
2394 Common Report RejectNegative Var(flag_stack_protect, 3) Init(-1) Optimization
2395 Use a smart stack protection method for certain functions.
2396
2397 fstack-protector-explicit
2398 Common Report RejectNegative Var(flag_stack_protect, 4) Optimization
2399 Use stack protection method only for functions with the stack_protect attribute.
2400
2401 fstack-usage
2402 Common RejectNegative Var(flag_stack_usage)
2403 Output stack usage information on a per-function basis.
2404
2405 fstrength-reduce
2406 Common Ignore
2407 Does nothing.  Preserved for backward compatibility.
2408
2409 ; Nonzero if we should do (language-dependent) alias analysis.
2410 ; Typically, this analysis will assume that expressions of certain
2411 ; types do not alias expressions of certain other types.  Only used
2412 ; if alias analysis (in general) is enabled.
2413 fstrict-aliasing
2414 Common Report Var(flag_strict_aliasing) Optimization
2415 Assume strict aliasing rules apply.
2416
2417 fstrict-overflow
2418 Common Report
2419 Treat signed overflow as undefined.  Negated as -fwrapv -fwrapv-pointer.
2420
2421 fsync-libcalls
2422 Common Report Var(flag_sync_libcalls) Init(1)
2423 Implement __atomic operations via libcalls to legacy __sync functions.
2424
2425 fsyntax-only
2426 Common Report Var(flag_syntax_only)
2427 Check for syntax errors, then stop.
2428
2429 ftest-coverage
2430 Common Report Var(flag_test_coverage)
2431 Create data files needed by \"gcov\".
2432
2433 fthread-jumps
2434 Common Report Var(flag_thread_jumps) Optimization
2435 Perform jump threading optimizations.
2436
2437 ftime-report
2438 Common Report Var(time_report)
2439 Report the time taken by each compiler pass.
2440
2441 ftime-report-details
2442 Common Report Var(time_report_details)
2443 Record times taken by sub-phases separately.
2444
2445 ftls-model=
2446 Common Joined RejectNegative Enum(tls_model) Var(flag_tls_default) Init(TLS_MODEL_GLOBAL_DYNAMIC)
2447 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec]      Set the default thread-local storage code generation model.
2448
2449 Enum
2450 Name(tls_model) Type(enum tls_model) UnknownError(unknown TLS model %qs)
2451
2452 EnumValue
2453 Enum(tls_model) String(global-dynamic) Value(TLS_MODEL_GLOBAL_DYNAMIC)
2454
2455 EnumValue
2456 Enum(tls_model) String(local-dynamic) Value(TLS_MODEL_LOCAL_DYNAMIC)
2457
2458 EnumValue
2459 Enum(tls_model) String(initial-exec) Value(TLS_MODEL_INITIAL_EXEC)
2460
2461 EnumValue
2462 Enum(tls_model) String(local-exec) Value(TLS_MODEL_LOCAL_EXEC)
2463
2464 ftoplevel-reorder
2465 Common Report Var(flag_toplevel_reorder) Init(2)
2466 Reorder top level functions, variables, and asms.
2467
2468 ftracer
2469 Common Report Var(flag_tracer) Optimization
2470 Perform superblock formation via tail duplication.
2471
2472 ftrampolines
2473 Common Report Var(flag_trampolines) Init(0)
2474 For targets that normally need trampolines for nested functions, always
2475 generate them instead of using descriptors.
2476
2477 ; Zero means that floating-point math operations cannot generate a
2478 ; (user-visible) trap.  This is the case, for example, in nonstop
2479 ; IEEE 754 arithmetic.
2480 ftrapping-math
2481 Common Report Var(flag_trapping_math) Init(1) Optimization SetByCombined
2482 Assume floating-point operations can trap.
2483
2484 ftrapv
2485 Common Report Var(flag_trapv) Optimization
2486 Trap for signed overflow in addition, subtraction and multiplication.
2487
2488 ftree-ccp
2489 Common Report Var(flag_tree_ccp) Optimization
2490 Enable SSA-CCP optimization on trees.
2491
2492 ftree-bit-ccp
2493 Common Report Var(flag_tree_bit_ccp) Optimization
2494 Enable SSA-BIT-CCP optimization on trees.
2495
2496 ftree-store-ccp
2497 Common Ignore
2498 Does nothing.  Preserved for backward compatibility.
2499
2500 ftree-ch
2501 Common Report Var(flag_tree_ch) Optimization
2502 Enable loop header copying on trees.
2503
2504 ftree-coalesce-inlined-vars
2505 Common Ignore RejectNegative
2506 Does nothing.  Preserved for backward compatibility.
2507
2508 ftree-coalesce-vars
2509 Common Report Var(flag_tree_coalesce_vars) Optimization
2510 Enable SSA coalescing of user variables.
2511
2512 ftree-copyrename
2513 Common Ignore
2514 Does nothing.  Preserved for backward compatibility.
2515
2516 ftree-copy-prop
2517 Common Report Var(flag_tree_copy_prop) Optimization
2518 Enable copy propagation on trees.
2519
2520 ftree-store-copy-prop
2521 Common Ignore
2522 Does nothing.  Preserved for backward compatibility.
2523
2524 ftree-cselim
2525 Common Report Var(flag_tree_cselim) Init(2) Optimization
2526 Transform condition stores into unconditional ones.
2527
2528 ftree-switch-conversion
2529 Common Report Var(flag_tree_switch_conversion) Optimization
2530 Perform conversions of switch initializations.
2531
2532 ftree-dce
2533 Common Report Var(flag_tree_dce) Optimization
2534 Enable SSA dead code elimination optimization on trees.
2535
2536 ftree-dominator-opts
2537 Common Report Var(flag_tree_dom) Optimization
2538 Enable dominator optimizations.
2539
2540 ftree-tail-merge
2541 Common Report Var(flag_tree_tail_merge) Optimization
2542 Enable tail merging on trees.
2543
2544 ftree-dse
2545 Common Report Var(flag_tree_dse) Optimization
2546 Enable dead store elimination.
2547
2548 ftree-forwprop
2549 Common Report Var(flag_tree_forwprop) Init(1) Optimization
2550 Enable forward propagation on trees.
2551
2552 ftree-fre
2553 Common Report Var(flag_tree_fre) Optimization
2554 Enable Full Redundancy Elimination (FRE) on trees.
2555
2556 foptimize-strlen
2557 Common Report Var(flag_optimize_strlen) Optimization
2558 Enable string length optimizations on trees.
2559
2560 fisolate-erroneous-paths-dereference
2561 Common Report Var(flag_isolate_erroneous_paths_dereference) Optimization
2562 Detect paths that trigger erroneous or undefined behavior due to
2563 dereferencing a null pointer.  Isolate those paths from the main control
2564 flow and turn the statement with erroneous or undefined behavior into a trap.
2565
2566 fisolate-erroneous-paths-attribute
2567 Common Report Var(flag_isolate_erroneous_paths_attribute) Optimization
2568 Detect paths that trigger erroneous or undefined behavior due to a null value
2569 being used in a way forbidden by a returns_nonnull or nonnull
2570 attribute.  Isolate those paths from the main control flow and turn the
2571 statement with erroneous or undefined behavior into a trap.
2572
2573 ftree-loop-distribution
2574 Common Report Var(flag_tree_loop_distribution) Optimization
2575 Enable loop distribution on trees.
2576
2577 ftree-loop-distribute-patterns
2578 Common Report Var(flag_tree_loop_distribute_patterns) Optimization
2579 Enable loop distribution for patterns transformed into a library call.
2580
2581 ftree-loop-im
2582 Common Report Var(flag_tree_loop_im) Init(1) Optimization
2583 Enable loop invariant motion on trees.
2584
2585 ftree-loop-linear
2586 Common Alias(floop-nest-optimize)
2587 Enable loop nest transforms.  Same as -floop-nest-optimize.
2588
2589 ftree-loop-ivcanon
2590 Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
2591 Create canonical induction variables in loops.
2592
2593 ftree-loop-optimize
2594 Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
2595 Enable loop optimizations on tree level.
2596
2597 ftree-parallelize-loops=
2598 Common Report Joined RejectNegative UInteger Var(flag_tree_parallelize_loops) Init(1) Optimization
2599 -ftree-parallelize-loops=<number>       Enable automatic parallelization of loops.
2600
2601 ftree-phiprop
2602 Common Report Var(flag_tree_phiprop) Init(1) Optimization
2603 Enable hoisting loads from conditional pointers.
2604
2605 ftree-pre
2606 Common Report Var(flag_tree_pre) Optimization
2607 Enable SSA-PRE optimization on trees.
2608
2609 ftree-partial-pre
2610 Common Report Var(flag_tree_partial_pre) Optimization
2611 In SSA-PRE optimization on trees, enable partial-partial redundancy elimination.
2612
2613 ftree-pta
2614 Common Report Var(flag_tree_pta) Optimization
2615 Perform function-local points-to analysis on trees.
2616
2617 ftree-reassoc
2618 Common Report Var(flag_tree_reassoc) Init(1) Optimization
2619 Enable reassociation on tree level.
2620
2621 ftree-salias
2622 Common Ignore
2623 Does nothing.  Preserved for backward compatibility.
2624
2625 ftree-sink
2626 Common Report Var(flag_tree_sink) Optimization
2627 Enable SSA code sinking on trees.
2628
2629 ftree-slsr
2630 Common Report Var(flag_tree_slsr) Optimization
2631 Perform straight-line strength reduction.
2632
2633 ftree-sra
2634 Common Report Var(flag_tree_sra) Optimization
2635 Perform scalar replacement of aggregates.
2636
2637 ftree-ter
2638 Common Report Var(flag_tree_ter) Optimization
2639 Replace temporary expressions in the SSA->normal pass.
2640
2641 ftree-lrs
2642 Common Report Var(flag_tree_live_range_split) Optimization
2643 Perform live range splitting during the SSA->normal pass.
2644
2645 ftree-vrp
2646 Common Report Var(flag_tree_vrp) Init(0) Optimization
2647 Perform Value Range Propagation on trees.
2648
2649 fsplit-paths
2650 Common Report Var(flag_split_paths) Init(0) Optimization
2651 Split paths leading to loop backedges.
2652
2653 funconstrained-commons
2654 Common Var(flag_unconstrained_commons) Optimization
2655 Assume common declarations may be overridden with ones with a larger
2656 trailing array.
2657
2658 funit-at-a-time
2659 Common Report Var(flag_unit_at_a_time) Init(1)
2660 Compile whole compilation unit at a time.
2661
2662 funroll-loops
2663 Common Report Var(flag_unroll_loops) Optimization
2664 Perform loop unrolling when iteration count is known.
2665
2666 funroll-all-loops
2667 Common Report Var(flag_unroll_all_loops) Optimization
2668 Perform loop unrolling for all loops.
2669
2670 ; Nonzero means that loop optimizer may assume that the induction variables
2671 ; that control loops do not overflow and that the loops with nontrivial
2672 ; exit condition are not infinite
2673 funsafe-loop-optimizations
2674 Common Ignore
2675 Does nothing.  Preserved for backward compatibility.
2676
2677 fassociative-math
2678 Common Report Var(flag_associative_math) SetByCombined Optimization
2679 Allow optimization for floating-point arithmetic which may change the
2680 result of the operation due to rounding.
2681
2682 freciprocal-math
2683 Common Report Var(flag_reciprocal_math) SetByCombined Optimization
2684 Same as -fassociative-math for expressions which include division.
2685
2686 ; Nonzero means that unsafe floating-point math optimizations are allowed
2687 ; for the sake of speed.  IEEE compliance is not guaranteed, and operations
2688 ; are allowed to assume that their arguments and results are "normal"
2689 ; (e.g., nonnegative for SQRT).
2690 funsafe-math-optimizations
2691 Common Report Var(flag_unsafe_math_optimizations) Optimization SetByCombined
2692 Allow math optimizations that may violate IEEE or ISO standards.
2693
2694 funswitch-loops
2695 Common Report Var(flag_unswitch_loops) Optimization
2696 Perform loop unswitching.
2697
2698 fsplit-loops
2699 Common Report Var(flag_split_loops) Optimization
2700 Perform loop splitting.
2701
2702 funwind-tables
2703 Common Report Var(flag_unwind_tables) Optimization
2704 Just generate unwind tables for exception handling.
2705
2706 fuse-ld=bfd
2707 Common Driver Negative(fuse-ld=gold)
2708 Use the bfd linker instead of the default linker.
2709
2710 fuse-ld=gold
2711 Common Driver Negative(fuse-ld=bfd)
2712 Use the gold linker instead of the default linker.
2713
2714 fuse-linker-plugin
2715 Common Undocumented Var(flag_use_linker_plugin)
2716
2717 ; Positive if we should track variables, negative if we should run
2718 ; the var-tracking pass only to discard debug annotations, zero if
2719 ; we're not to run it.  When flag_var_tracking == 2 (AUTODETECT_VALUE) it
2720 ; will be set according to optimize, debug_info_level and debug_hooks
2721 ; in process_options ().
2722 fvar-tracking
2723 Common Report Var(flag_var_tracking) Init(2) PerFunction
2724 Perform variable tracking.
2725
2726 ; Positive if we should track variables at assignments, negative if
2727 ; we should run the var-tracking pass only to discard debug
2728 ; annotations.  When flag_var_tracking_assignments ==
2729 ; AUTODETECT_VALUE it will be set according to flag_var_tracking.
2730 fvar-tracking-assignments
2731 Common Report Var(flag_var_tracking_assignments) Init(2) PerFunction
2732 Perform variable tracking by annotating assignments.
2733
2734 ; Nonzero if we should toggle flag_var_tracking_assignments after
2735 ; processing options and computing its default.  */
2736 fvar-tracking-assignments-toggle
2737 Common Report Var(flag_var_tracking_assignments_toggle) PerFunction
2738 Toggle -fvar-tracking-assignments.
2739
2740 ; Positive if we should track uninitialized variables, negative if
2741 ; we should run the var-tracking pass only to discard debug
2742 ; annotations.  When flag_var_tracking_uninit == AUTODETECT_VALUE it
2743 ; will be set according to flag_var_tracking.
2744 fvar-tracking-uninit
2745 Common Report Var(flag_var_tracking_uninit) PerFunction
2746 Perform variable tracking and also tag variables that are uninitialized.
2747
2748 ; Alias to enable both -ftree-loop-vectorize and -ftree-slp-vectorize.
2749 ftree-vectorize
2750 Common Report Optimization
2751 Enable vectorization on trees.
2752
2753 ftree-vectorizer-verbose=
2754 Common Joined RejectNegative Ignore
2755 Does nothing.  Preserved for backward compatibility.
2756
2757 ftree-loop-vectorize
2758 Common Report Var(flag_tree_loop_vectorize) Optimization EnabledBy(ftree-vectorize)
2759 Enable loop vectorization on trees.
2760
2761 ftree-slp-vectorize
2762 Common Report Var(flag_tree_slp_vectorize) Optimization EnabledBy(ftree-vectorize)
2763 Enable basic block vectorization (SLP) on trees.
2764
2765 fvect-cost-model=
2766 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_vect_cost_model) Init(VECT_COST_MODEL_DEFAULT) Optimization
2767 Specifies the cost model for vectorization.
2768 -fvect-cost-model=[unlimited|dynamic|cheap]     Specifies the cost model for vectorization.
2769
2770 fsimd-cost-model=
2771 Common Joined RejectNegative Enum(vect_cost_model) Var(flag_simd_cost_model) Init(VECT_COST_MODEL_UNLIMITED) Optimization
2772 -fsimd-cost-model=[unlimited|dynamic|cheap]     Specifies the vectorization cost model for code marked with a simd directive.
2773
2774 Enum
2775 Name(vect_cost_model) Type(enum vect_cost_model) UnknownError(unknown vectorizer cost model %qs)
2776
2777 EnumValue
2778 Enum(vect_cost_model) String(unlimited) Value(VECT_COST_MODEL_UNLIMITED)
2779
2780 EnumValue
2781 Enum(vect_cost_model) String(dynamic) Value(VECT_COST_MODEL_DYNAMIC)
2782
2783 EnumValue
2784 Enum(vect_cost_model) String(cheap) Value(VECT_COST_MODEL_CHEAP)
2785
2786 fvect-cost-model
2787 Common Alias(fvect-cost-model=,dynamic,unlimited)
2788 Enables the dynamic vectorizer cost model.  Preserved for backward compatibility.
2789
2790 ftree-vect-loop-version
2791 Common Ignore
2792 Does nothing. Preserved for backward compatibility.
2793
2794 ftree-scev-cprop
2795 Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
2796 Enable copy propagation of scalar-evolution information.
2797
2798 ; -fverbose-asm causes extra commentary information to be produced in
2799 ; the generated assembly code (to make it more readable).  This option
2800 ; is generally only of use to those who actually need to read the
2801 ; generated assembly code (perhaps while debugging the compiler itself).
2802 ; -fno-verbose-asm, the default, causes the extra information
2803 ; to not be added and is useful when comparing two assembler files.
2804 fverbose-asm
2805 Common Report Var(flag_verbose_asm)
2806 Add extra commentary to assembler output.
2807
2808 fvisibility=
2809 Common Joined RejectNegative Enum(symbol_visibility) Var(default_visibility) Init(VISIBILITY_DEFAULT)
2810 -fvisibility=[default|internal|hidden|protected]        Set the default symbol visibility.
2811
2812 Enum
2813 Name(symbol_visibility) Type(enum symbol_visibility) UnknownError(unrecognized visibility value %qs)
2814
2815 EnumValue
2816 Enum(symbol_visibility) String(default) Value(VISIBILITY_DEFAULT)
2817
2818 EnumValue
2819 Enum(symbol_visibility) String(internal) Value(VISIBILITY_INTERNAL)
2820
2821 EnumValue
2822 Enum(symbol_visibility) String(hidden) Value(VISIBILITY_HIDDEN)
2823
2824 EnumValue
2825 Enum(symbol_visibility) String(protected) Value(VISIBILITY_PROTECTED)
2826
2827 fvtable-verify=
2828 Common Joined RejectNegative Enum(vtv_priority) Var(flag_vtable_verify) Init(VTV_NO_PRIORITY)
2829 Validate vtable pointers before using them.
2830
2831 Enum
2832 Name(vtv_priority) Type(enum vtv_priority) UnknownError(unknown vtable verify initialization priority %qs)
2833
2834 EnumValue
2835 Enum(vtv_priority) String(none) Value(VTV_NO_PRIORITY)
2836
2837 EnumValue
2838 Enum(vtv_priority) String(std) Value(VTV_STANDARD_PRIORITY)
2839
2840 EnumValue
2841 Enum(vtv_priority) String(preinit) Value(VTV_PREINIT_PRIORITY)
2842
2843 fvtv-counts
2844 Common Var(flag_vtv_counts)
2845 Output vtable verification counters.
2846
2847 fvtv-debug
2848 Common Var(flag_vtv_debug)
2849 Output vtable verification pointer sets information.
2850
2851 fvpt
2852 Common Report Var(flag_value_profile_transformations) Optimization
2853 Use expression value profiles in optimizations.
2854
2855 fweb
2856 Common Report Var(flag_web) Init(2) Optimization
2857 Construct webs and split unrelated uses of single variable.
2858
2859 ftree-builtin-call-dce
2860 Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization
2861 Enable conditional dead code elimination for builtin calls.
2862
2863 fwhole-program
2864 Common Report Var(flag_whole_program) Init(0)
2865 Perform whole program optimizations.
2866
2867 fwrapv-pointer
2868 Common Report Var(flag_wrapv_pointer) Optimization
2869 Assume pointer overflow wraps around.
2870
2871 fwrapv
2872 Common Report Var(flag_wrapv) Optimization
2873 Assume signed arithmetic overflow wraps around.
2874
2875 fzero-initialized-in-bss
2876 Common Report Var(flag_zero_initialized_in_bss) Init(1)
2877 Put zero initialized data in the bss section.
2878
2879 g
2880 Common Driver RejectNegative JoinedOrMissing
2881 Generate debug information in default format.
2882
2883 gas-loc-support
2884 Common Driver Var(dwarf2out_as_loc_support) Init(2)
2885 Assume assembler support for (DWARF2+) .loc directives
2886
2887 gas-locview-support
2888 Common Driver Var(dwarf2out_as_locview_support) Init(2)
2889 Assume assembler support for view in (DWARF2+) .loc directives
2890
2891 gcoff
2892 Common Driver Ignore Warn(switch %qs no longer supported)
2893 Does nothing.  Preserved for backward compatibility.
2894
2895 gcoff1
2896 Common Driver Ignore Warn(switch %qs no longer supported)
2897 Does nothing.  Preserved for backward compatibility.
2898
2899 gcoff2
2900 Common Driver Ignore Warn(switch %qs no longer supported)
2901 Does nothing.  Preserved for backward compatibility.
2902
2903 gcoff3
2904 Common Driver Ignore Warn(switch %qs no longer supported)
2905 Does nothing.  Preserved for backward compatibility.
2906
2907 gcolumn-info
2908 Common Driver Var(debug_column_info,1) Init(1)
2909 Record DW_AT_decl_column and DW_AT_call_column in DWARF.
2910
2911 gdwarf
2912 Common Driver JoinedOrMissing Negative(gdwarf-)
2913 Generate debug information in default version of DWARF format.
2914
2915 gdwarf-
2916 Common Driver Joined UInteger Var(dwarf_version) Init(4) Negative(gstabs)
2917 Generate debug information in DWARF v2 (or later) format.
2918
2919 ggdb
2920 Common Driver JoinedOrMissing
2921 Generate debug information in default extended format.
2922
2923 ginline-points
2924 Common Driver Var(debug_inline_points) Init(2)
2925 Generate extended entry point information for inlined functions
2926
2927 ginternal-reset-location-views
2928 Common Driver Var(debug_internal_reset_location_views) Init(2)
2929 Compute locview reset points based on insn length estimates
2930
2931 gno-
2932 RejectNegative Joined Undocumented
2933 ; Catch the gno- prefix, so it doesn't backtrack to g<level>.
2934
2935 gno-pubnames
2936 Common Driver Negative(gpubnames) Var(debug_generate_pub_sections, 0) Init(-1)
2937 Don't generate DWARF pubnames and pubtypes sections.
2938
2939 gpubnames
2940 Common Driver Negative(ggnu-pubnames) Var(debug_generate_pub_sections, 1)
2941 Generate DWARF pubnames and pubtypes sections.
2942
2943 ggnu-pubnames
2944 Common Driver Negative(gno-pubnames) Var(debug_generate_pub_sections, 2)
2945 Generate DWARF pubnames and pubtypes sections with GNU extensions.
2946
2947 grecord-gcc-switches
2948 Common Driver Var(dwarf_record_gcc_switches) Init(1)
2949 Record gcc command line switches in DWARF DW_AT_producer.
2950
2951 gsplit-dwarf
2952 Common Driver Var(dwarf_split_debug_info) Init(0)
2953 Generate debug information in separate .dwo files.
2954
2955 gstabs
2956 Common Driver JoinedOrMissing Negative(gstabs+)
2957 Generate debug information in STABS format.
2958
2959 gstabs+
2960 Common Driver JoinedOrMissing Negative(gvms)
2961 Generate debug information in extended STABS format.
2962
2963 gstatement-frontiers
2964 Common Driver Var(debug_nonbind_markers_p) Init(2)
2965 Emit progressive recommended breakpoint locations.
2966
2967 gstrict-dwarf
2968 Common Driver Report Var(dwarf_strict) Init(0)
2969 Don't emit DWARF additions beyond selected version.
2970
2971 gtoggle
2972 Common Driver Report Var(flag_gtoggle)
2973 Toggle debug information generation.
2974
2975 gvariable-location-views
2976 Common Driver Var(debug_variable_location_views, 1) Init(2)
2977 Augment variable location lists with progressive views.
2978
2979 gvariable-location-views=incompat5
2980 Common Driver RejectNegative Var(debug_variable_location_views, -1) Init(2)
2981
2982 gvms
2983 Common Driver JoinedOrMissing Negative(gxcoff)
2984 Generate debug information in VMS format.
2985
2986 gxcoff
2987 Common Driver JoinedOrMissing Negative(gxcoff+)
2988 Generate debug information in XCOFF format.
2989
2990 gxcoff+
2991 Common Driver JoinedOrMissing Negative(gdwarf)
2992 Generate debug information in extended XCOFF format.
2993
2994 Enum
2995 Name(compressed_debug_sections) Type(int)
2996
2997 ; Since -gz= is completely handled in specs, the values aren't used and we
2998 ; assign arbitrary constants.
2999 EnumValue
3000 Enum(compressed_debug_sections) String(none) Value(0)
3001
3002 EnumValue
3003 Enum(compressed_debug_sections) String(zlib) Value(1)
3004
3005 EnumValue
3006 Enum(compressed_debug_sections) String(zlib-gnu) Value(2)
3007
3008 gz
3009 Common Driver
3010 Generate compressed debug sections.
3011
3012 gz=
3013 Common Driver RejectNegative Joined Enum(compressed_debug_sections)
3014 -gz=<format>    Generate compressed debug sections in format <format>.
3015
3016 h
3017 Driver Joined Separate
3018
3019 iplugindir=
3020 Common Joined Var(plugindir_string) Init(0)
3021 -iplugindir=<dir>       Set <dir> to be the default plugin directory.
3022
3023 imultiarch
3024 Common Joined Separate RejectDriver Var(imultiarch) Init(0)
3025 -imultiarch <dir>       Set <dir> to be the multiarch include subdirectory.
3026
3027 l
3028 Driver Joined Separate
3029
3030 n
3031 Driver
3032
3033 no-canonical-prefixes
3034 Driver
3035
3036 nodefaultlibs
3037 Driver
3038
3039 nostartfiles
3040 Driver
3041
3042 nostdlib
3043 Driver
3044
3045 o
3046 Common Driver Joined Separate Var(asm_file_name) MissingArgError(missing filename after %qs)
3047 -o <file>       Place output into <file>.
3048
3049 p
3050 Common Var(profile_flag)
3051 Enable function profiling.
3052
3053 pass-exit-codes
3054 Driver Var(pass_exit_codes)
3055
3056 pedantic
3057 Common Alias(Wpedantic)
3058
3059 pedantic-errors
3060 Common Var(flag_pedantic_errors)
3061 Like -pedantic but issue them as errors.
3062
3063 pg
3064 Driver
3065
3066 pipe
3067 Driver Var(use_pipes)
3068
3069 print-file-name=
3070 Driver JoinedOrMissing Var(print_file_name)
3071
3072 print-libgcc-file-name
3073 Driver
3074
3075 print-multi-directory
3076 Driver Var(print_multi_directory)
3077
3078 print-multi-lib
3079 Driver Var(print_multi_lib)
3080
3081 print-multi-os-directory
3082 Driver Var(print_multi_os_directory)
3083
3084 print-multiarch
3085 Driver Var(print_multiarch)
3086
3087 print-prog-name=
3088 Driver JoinedOrMissing Var(print_prog_name)
3089
3090 print-search-dirs
3091 Driver Var(print_search_dirs)
3092
3093 print-sysroot
3094 Driver Var(print_sysroot)
3095
3096 print-sysroot-headers-suffix
3097 Driver Var(print_sysroot_headers_suffix)
3098
3099 quiet
3100 Common Var(quiet_flag) RejectDriver
3101 Do not display functions compiled or elapsed time.
3102
3103 r
3104 Driver
3105
3106 s
3107 Driver
3108
3109 save-temps
3110 Driver
3111
3112 save-temps=
3113 Driver Joined
3114
3115 t
3116 Driver
3117
3118 time
3119 Driver Var(report_times)
3120
3121 time=
3122 Driver JoinedOrMissing
3123
3124 u
3125 Driver Joined Separate
3126
3127 undef
3128 Driver
3129 ; C option, but driver must not handle as "-u ndef".
3130
3131 v
3132 Common Driver Var(verbose_flag)
3133 Enable verbose output.
3134
3135 version
3136 Common Var(version_flag) RejectDriver
3137 Display the compiler's version.
3138
3139 w
3140 Common Var(inhibit_warnings)
3141 Suppress warnings.
3142
3143 wrapper
3144 Driver Separate Var(wrapper_string)
3145
3146 x
3147 Driver Joined Separate
3148
3149 shared
3150 Driver RejectNegative Negative(static-pie)
3151 Create a shared library.
3152
3153 shared-libgcc
3154 Driver
3155
3156 specs
3157 Driver Separate Alias(specs=)
3158
3159 specs=
3160 Driver Joined
3161
3162 static
3163 Driver
3164
3165 static-libgcc
3166 Driver
3167
3168 static-libgfortran
3169 Driver
3170 ; Documented for Fortran, but always accepted by driver.
3171
3172 static-libstdc++
3173 Driver
3174
3175 static-libgo
3176 Driver
3177 ; Documented for Go, but always accepted by driver.
3178
3179 static-libasan
3180 Driver
3181
3182 static-libtsan
3183 Driver
3184
3185 static-liblsan
3186 Driver
3187
3188 static-libubsan
3189 Driver
3190
3191 symbolic
3192 Driver
3193
3194 no-pie
3195 Driver RejectNegative Negative(shared)
3196 Don't create a dynamically linked position independent executable.
3197
3198 pie
3199 Driver RejectNegative Negative(no-pie)
3200 Create a dynamically linked position independent executable.
3201
3202 static-pie
3203 Driver RejectNegative Negative(pie)
3204 Create a static position independent executable.
3205
3206 z
3207 Driver Joined Separate
3208
3209 fipa-ra
3210 Common Report Var(flag_ipa_ra) Optimization
3211 Use caller save register across calls if possible.
3212
3213 ; This comment is to ensure we retain the blank line above.