gcc/common.opt

   1 ; Options for the language- and target-independent parts of the compiler.
   2
   3 ; Copyright (C) 2003, 2004, 2005, 2006 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 2, 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 COPYING.  If not, write to the Free
  19 ; Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
  20 ; 02110-1301, USA.
  21
  22 ; See the GCC internals manual for a description of this file's format.
  23
  24 ; Please try to keep this file in ASCII collating order.
  25
  26 -help
  27 Common
  28 Display this information
  29
  30 -param
  31 Common Separate
  32 --param <param>=<value> Set parameter <param> to value.  See below for a complete list of parameters
  33
  34 -target-help
  35 Common
  36
  37 -version
  38 Common
  39
  40 G
  41 Common Joined Separate UInteger
  42 -G<number>      Put global and static data smaller than <number> bytes into a special section (on some targets)
  43
  44 O
  45 Common JoinedOrMissing
  46 -O<number>      Set optimization level to <number>
  47
  48 Os
  49 Common
  50 Optimize for space rather than speed
  51
  52 W
  53 Common RejectNegative
  54 This switch is deprecated; use -Wextra instead
  55
  56 Waggregate-return
  57 Common Var(warn_aggregate_return)
  58 Warn about returning structures, unions or arrays
  59
  60 Walways-true
  61 Common Var(warn_always_true)
  62 Warn about comparisons that always evaluate to true
  63
  64 Warray-bounds
  65 Common Var(warn_array_bounds)
  66 Warn if an array is accessed out of bounds
  67
  68 Wattributes
  69 Common Var(warn_attributes) Init(1)
  70 Warn about inappropriate attribute usage
  71
  72 Wcast-align
  73 Common Var(warn_cast_align)
  74 Warn about pointer casts which increase alignment
  75
  76 Wdeprecated-declarations
  77 Common Var(warn_deprecated_decl) Init(1)
  78 Warn about uses of __attribute__((deprecated)) declarations
  79
  80 Wdisabled-optimization
  81 Common Var(warn_disabled_optimization)
  82 Warn when an optimization pass is disabled
  83
  84 Werror
  85 Common Var(warnings_are_errors)
  86 Treat all warnings as errors
  87
  88 Werror=
  89 Common Joined
  90 Treat specified warning as error
  91
  92 Wextra
  93 Common
  94 Print extra (possibly unwanted) warnings
  95
  96 Wfatal-errors
  97 Common Var(flag_fatal_errors)
  98 Exit on the first error occurred
  99
 100 Winline
 101 Common Var(warn_inline)
 102 Warn when an inlined function cannot be inlined
 103
 104 Wlarger-than-
 105 Common RejectNegative Joined UInteger
 106 -Wlarger-than-<number>  Warn if an object is larger than <number> bytes
 107
 108 Wunsafe-loop-optimizations
 109 Common Var(warn_unsafe_loop_optimizations)
 110 Warn if the loop cannot be optimized due to nontrivial assumptions.
 111
 112 Wmissing-noreturn
 113 Common Var(warn_missing_noreturn)
 114 Warn about functions which might be candidates for __attribute__((noreturn))
 115
 116 Woverflow
 117 Common Var(warn_overflow) Init(1)
 118 Warn about overflow in arithmetic expressions
 119
 120 Wpacked
 121 Common Var(warn_packed)
 122 Warn when the packed attribute has no effect on struct layout
 123
 124 Wpadded
 125 Common Var(warn_padded)
 126 Warn when padding is required to align structure members
 127
 128 Wshadow
 129 Common Var(warn_shadow)
 130 Warn when one local variable shadows another
 131
 132 Wstack-protector
 133 Common Var(warn_stack_protect)
 134 Warn when not issuing stack smashing protection for some reason
 135
 136 Wstrict-aliasing
 137 Common
 138 Warn about code which might break strict aliasing rules
 139
 140 Wstrict-aliasing=
 141 Common Joined UInteger
 142 Warn about code which might break strict aliasing rules
 143
 144 Wstring-literal-comparison
 145 Common Var(warn_string_literal_comparison)
 146 Warn about comparisons to constant string literals
 147
 148 Wswitch
 149 Common Var(warn_switch)
 150 Warn about enumerated switches, with no default, missing a case
 151
 152 Wswitch-default
 153 Common Var(warn_switch_default)
 154 Warn about enumerated switches missing a \"default:\" statement
 155
 156 Wswitch-enum
 157 Common Var(warn_switch_enum)
 158 Warn about all enumerated switches missing a specific case
 159
 160 Wsystem-headers
 161 Common Var(warn_system_headers)
 162 Do not suppress warnings from system headers
 163
 164 Wuninitialized
 165 Common Var(warn_uninitialized)
 166 Warn about uninitialized automatic variables
 167
 168 Wunreachable-code
 169 Common Var(warn_notreached)
 170 Warn about code that will never be executed
 171
 172 Wunused
 173 Common
 174 Enable all -Wunused- warnings
 175
 176 Wunused-function
 177 Common Var(warn_unused_function)
 178 Warn when a function is unused
 179
 180 Wunused-label
 181 Common Var(warn_unused_label)
 182 Warn when a label is unused
 183
 184 Wunused-parameter
 185 Common Var(warn_unused_parameter)
 186 Warn when a function parameter is unused
 187
 188 Wunused-value
 189 Common Var(warn_unused_value)
 190 Warn when an expression value is unused
 191
 192 Wunused-variable
 193 Common Var(warn_unused_variable)
 194 Warn when a variable is unused
 195
 196 Wvolatile-register-var
 197 Common Var(warn_register_var)
 198 Warn when a register variable is declared volatile
 199
 200 aux-info
 201 Common Separate
 202 -aux-info <file>        Emit declaration information into <file>
 203
 204 aux-info=
 205 Common Joined
 206
 207 auxbase
 208 Common Separate
 209
 210 auxbase-strip
 211 Common Separate
 212
 213 d
 214 Common Joined
 215 -d<letters>     Enable dumps from specific passes of the compiler
 216
 217 dumpbase
 218 Common Separate
 219 -dumpbase <file>        Set the file basename to be used for dumps
 220
 221 ; The version of the C++ ABI in use.  The following values are allowed:
 222 ;
 223 ; 0: The version of the ABI believed most conformant with the C++ ABI
 224 ;    specification.  This ABI may change as bugs are discovered and fixed.
 225 ;    Therefore, 0 will not necessarily indicate the same ABI in different
 226 ;    versions of G++.
 227 ;
 228 ; 1: The version of the ABI first used in G++ 3.2.
 229 ;
 230 ; Additional positive integers will be assigned as new versions of
 231 ; the ABI become the default version of the ABI.
 232 fabi-version=
 233 Common Joined UInteger Var(flag_abi_version) Init(2)
 234
 235 falign-functions
 236 Common Report Var(align_functions,0)
 237 Align the start of functions
 238
 239 falign-functions=
 240 Common RejectNegative Joined UInteger
 241
 242 falign-jumps
 243 Common Report Var(align_jumps,0)
 244 Align labels which are only reached by jumping
 245
 246 falign-jumps=
 247 Common RejectNegative Joined UInteger
 248
 249 falign-labels
 250 Common Report Var(align_labels,0)
 251 Align all labels
 252
 253 falign-labels=
 254 Common RejectNegative Joined UInteger
 255
 256 falign-loops
 257 Common Report Var(align_loops)
 258 Align the start of loops
 259
 260 falign-loops=
 261 Common RejectNegative Joined UInteger
 262
 263 ; This flag is only tested if alias checking is enabled.
 264 ; 0 if pointer arguments may alias each other.  True in C.
 265 ; 1 if pointer arguments may not alias each other but may alias
 266 ;   global variables.
 267 ; 2 if pointer arguments may not alias each other and may not
 268 ;   alias global variables.
 269 ; 3 if pointer arguments may not alias anything.  True in Fortran.
 270 ;   Set by the front end.
 271 fargument-alias
 272 Common Report Var(flag_argument_noalias,0)
 273 Specify that arguments may alias each other and globals
 274
 275 fargument-noalias
 276 Common Report Var(flag_argument_noalias,1) VarExists
 277 Assume arguments may alias globals but not each other
 278
 279 fargument-noalias-global
 280 Common Report Var(flag_argument_noalias,2) VarExists
 281 Assume arguments alias neither each other nor globals
 282
 283 fargument-noalias-anything
 284 Common Report Var(flag_argument_noalias,3) VarExists
 285 Assume arguments alias no other storage
 286
 287 fasynchronous-unwind-tables
 288 Common Report Var(flag_asynchronous_unwind_tables)
 289 Generate unwind tables that are exact at each instruction boundary
 290
 291 ; -fcheck-bounds causes gcc to generate array bounds checks.
 292 ; For C, C++ and ObjC: defaults off.
 293 ; For Java: defaults to on.
 294 ; For Fortran: defaults to off.
 295 fbounds-check
 296 Common Report Var(flag_bounds_check)
 297 Generate code to check bounds before indexing arrays
 298
 299 fbranch-count-reg
 300 Common Report Var(flag_branch_on_count_reg) Init(1)
 301 Replace add, compare, branch with branch on count register
 302
 303 fbranch-probabilities
 304 Common Report Var(flag_branch_probabilities)
 305 Use profiling information for branch probabilities
 306
 307 fbranch-target-load-optimize
 308 Common Report Var(flag_branch_target_load_optimize)
 309 Perform branch target load optimization before prologue / epilogue threading
 310
 311 fbranch-target-load-optimize2
 312 Common Report Var(flag_branch_target_load_optimize2)
 313 Perform branch target load optimization after prologue / epilogue threading
 314
 315 fbtr-bb-exclusive
 316 Common Report Var(flag_btr_bb_exclusive)
 317 Restrict target load migration not to re-use registers in any basic block
 318
 319 fcall-saved-
 320 Common Joined RejectNegative
 321 -fcall-saved-<register> Mark <register> as being preserved across functions
 322
 323 fcall-used-
 324 Common Joined RejectNegative
 325 -fcall-used-<register>  Mark <register> as being corrupted by function calls
 326
 327 ; Nonzero for -fcaller-saves: allocate values in regs that need to
 328 ; be saved across function calls, if that produces overall better code.
 329 ; Optional now, so people can test it.
 330 fcaller-saves
 331 Common Report Var(flag_caller_saves)
 332 Save registers around function calls
 333
 334 fcommon
 335 Common Report Var(flag_no_common,0)
 336 Do not put uninitialized globals in the common section
 337
 338 fcprop-registers
 339 Common Report Var(flag_cprop_registers)
 340 Perform a register copy-propagation optimization pass
 341
 342 fcrossjumping
 343 Common Report Var(flag_crossjumping)
 344 Perform cross-jumping optimization
 345
 346 fcse-follow-jumps
 347 Common Report Var(flag_cse_follow_jumps)
 348 When running CSE, follow jumps to their targets
 349
 350 fcse-skip-blocks
 351 Common Report Var(flag_cse_skip_blocks)
 352 When running CSE, follow conditional jumps
 353
 354 fcx-limited-range
 355 Common Report Var(flag_cx_limited_range)
 356 Omit range reduction step when performing complex division
 357
 358 fdata-sections
 359 Common Report Var(flag_data_sections)
 360 Place data items into their own section
 361
 362 ; Nonzero for -fdefer-pop: don't pop args after each function call
 363 ; instead save them up to pop many calls' args with one insns.
 364 fdefer-pop
 365 Common Report Var(flag_defer_pop)
 366 Defer popping functions args from stack until later
 367
 368 fdelayed-branch
 369 Common Report Var(flag_delayed_branch)
 370 Attempt to fill delay slots of branch instructions
 371
 372 fdelete-null-pointer-checks
 373 Common Report Var(flag_delete_null_pointer_checks)
 374 Delete useless null pointer checks
 375
 376 fdiagnostics-show-location=
 377 Common Joined RejectNegative
 378 -fdiagnostics-show-location=[once|every-line]   How often to emit source location at the beginning of line-wrapped diagnostics
 379
 380 fdiagnostics-show-option
 381 Common
 382 Amend appropriate diagnostic messages with the command line option that controls them
 383
 384 fdump-
 385 Common Joined RejectNegative
 386 -fdump-<type>   Dump various compiler internals to a file
 387
 388 fdump-noaddr
 389 Common Report Var(flag_dump_noaddr)
 390 Suppress output of addresses in debugging dumps
 391
 392 fdump-unnumbered
 393 Common Report Var(flag_dump_unnumbered) VarExists
 394 Suppress output of instruction numbers, line number notes and addresses in debugging dumps
 395
 396 fearly-inlining
 397 Common Report Var(flag_early_inlining) Init(1)
 398 Perform early inlining
 399
 400 feliminate-dwarf2-dups
 401 Common Report Var(flag_eliminate_dwarf2_dups)
 402 Perform DWARF2 duplicate elimination
 403
 404 feliminate-unused-debug-symbols
 405 Common Report Var(flag_debug_only_used_symbols)
 406 Perform unused type elimination in debug info
 407
 408 feliminate-unused-debug-types
 409 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
 410 Perform unused type elimination in debug info
 411
 412 femit-class-debug-always
 413 Common Report Var(flag_emit_class_debug_always) Init(1)
 414 Do not suppress C++ class debug information.
 415
 416 fexceptions
 417 Common Report Var(flag_exceptions)
 418 Enable exception handling
 419
 420 fexpensive-optimizations
 421 Common Report Var(flag_expensive_optimizations)
 422 Perform a number of minor, expensive optimizations
 423
 424 ffast-math
 425 Common
 426
 427 ffinite-math-only
 428 Common Report Var(flag_finite_math_only)
 429 Assume no NaNs or infinities are generated
 430
 431 ffixed-
 432 Common Joined RejectNegative
 433 -ffixed-<register>      Mark <register> as being unavailable to the compiler
 434
 435 ffloat-store
 436 Common Report Var(flag_float_store)
 437 Don't allocate floats and doubles in extended-precision registers
 438
 439 ; Nonzero for -fforce-addr: load memory address into a register before
 440 ; reference to memory.  This makes better cse but slower compilation.
 441 fforce-addr
 442 Common Report Var(flag_force_addr)
 443 Copy memory address constants into registers before use
 444
 445 fforward-propagate
 446 Common Report Var(flag_forward_propagate)
 447 Perform a forward propagation pass on RTL
 448
 449 ; Nonzero means don't put addresses of constant functions in registers.
 450 ; Used for compiling the Unix kernel, where strange substitutions are
 451 ; done on the assembly output.
 452 ffunction-cse
 453 Common Report Var(flag_no_function_cse,0)
 454 Allow function addresses to be held in registers
 455
 456 ffunction-sections
 457 Common Report Var(flag_function_sections)
 458 Place each function into its own section
 459
 460 fgcse
 461 Common Report Var(flag_gcse)
 462 Perform global common subexpression elimination
 463
 464 fgcse-lm
 465 Common Report Var(flag_gcse_lm) Init(1)
 466 Perform enhanced load motion during global common subexpression elimination
 467
 468 fgcse-sm
 469 Common Report Var(flag_gcse_sm) Init(0)
 470 Perform store motion after global common subexpression elimination
 471
 472 fgcse-las
 473 Common Report Var(flag_gcse_las) Init(0)
 474 Perform redundant load after store elimination in global common subexpression
 475 elimination
 476
 477 fgcse-after-reload
 478 Common Report Var(flag_gcse_after_reload)
 479 Perform global common subexpression elimination after register allocation
 480 has finished
 481
 482 fguess-branch-probability
 483 Common Report Var(flag_guess_branch_prob)
 484 Enable guessing of branch probabilities
 485
 486 ; Nonzero means ignore `#ident' directives.  0 means handle them.
 487 ; Generate position-independent code for executables if possible
 488 ; On SVR4 targets, it also controls whether or not to emit a
 489 ; string identifying the compiler.
 490 fident
 491 Common Report Var(flag_no_ident,0)
 492 Process #ident directives
 493
 494 fif-conversion
 495 Common Report Var(flag_if_conversion)
 496 Perform conversion of conditional jumps to branchless equivalents
 497
 498 fif-conversion2
 499 Common Report Var(flag_if_conversion2)
 500 Perform conversion of conditional jumps to conditional execution
 501
 502 ; -finhibit-size-directive inhibits output of .size for ELF.
 503 ; This is used only for compiling crtstuff.c,
 504 ; and it may be extended to other effects
 505 ; needed for crtstuff.c on other systems.
 506 finhibit-size-directive
 507 Common Report Var(flag_inhibit_size_directive)
 508 Do not generate .size directives
 509
 510 ; Nonzero means that functions declared `inline' will be treated
 511 ; as `static'.  Prevents generation of zillions of copies of unused
 512 ; static inline functions; instead, `inlines' are written out
 513 ; only when actually used.  Used in conjunction with -g.  Also
 514 ; does the right thing with #pragma interface.
 515 finline
 516 Common Report Var(flag_no_inline,0) Init(2)
 517 Pay attention to the \"inline\" keyword
 518
 519 finline-functions
 520 Common Report Var(flag_inline_functions)
 521 Integrate simple functions into their callers
 522
 523 finline-functions-called-once
 524 Common Report Var(flag_inline_functions_called_once) Init(1)
 525 Integrate functions called once into their callers
 526
 527 finline-limit-
 528 Common RejectNegative Joined UInteger
 529
 530 finline-limit=
 531 Common RejectNegative Joined UInteger
 532 -finline-limit=<number> Limit the size of inlined functions to <number>
 533
 534 finstrument-functions
 535 Common Report Var(flag_instrument_function_entry_exit)
 536 Instrument function entry and exit with profiling calls
 537
 538 fipa-cp
 539 Common Report Var(flag_ipa_cp)
 540 Perform Interprocedural constant propagation
 541
 542 fipa-pure-const
 543 Common Report Var(flag_ipa_pure_const) Init(0)
 544 Discover pure and const functions
 545
 546 fipa-pta
 547 Common Report Var(flag_ipa_pta) Init(0)
 548 Perform interprocedural points-to analysis
 549
 550 fipa-reference
 551 Common Report Var(flag_ipa_reference) Init(0)
 552 Discover readonly and non addressable static variables
 553
 554 fipa-type-escape
 555 Common Report Var(flag_ipa_type_escape) Init(0)
 556 Type based escape and alias analysis
 557
 558 fivopts
 559 Common Report Var(flag_ivopts) Init(1)
 560 Optimize induction variables on trees
 561
 562 fjump-tables
 563 Common Var(flag_jump_tables) Init(1)
 564 Use jump tables for sufficiently large switch statements
 565
 566 fkeep-inline-functions
 567 Common Report Var(flag_keep_inline_functions)
 568 Generate code for functions even if they are fully inlined
 569
 570 fkeep-static-consts
 571 Common Report Var(flag_keep_static_consts) Init(1)
 572 Emit static const variables even if they are not used
 573
 574 fleading-underscore
 575 Common Report Var(flag_leading_underscore) Init(-1)
 576 Give external symbols a leading underscore
 577
 578 floop-optimize
 579 Common
 580 Does nothing.  Preserved for backward compatibility.
 581
 582 fmath-errno
 583 Common Report Var(flag_errno_math) Init(1)
 584 Set errno after built-in math functions
 585
 586 fmem-report
 587 Common Report Var(mem_report)
 588 Report on permanent memory allocation
 589
 590 ; This will attempt to merge constant section constants, if 1 only
 591 ; string constants and constants from constant pool, if 2 also constant
 592 ; variables.
 593 fmerge-all-constants
 594 Common Report Var(flag_merge_constants,2) Init(1)
 595 Attempt to merge identical constants and constant variables
 596
 597 fmerge-constants
 598 Common Report Var(flag_merge_constants,1) VarExists
 599 Attempt to merge identical constants across compilation units
 600
 601 fmessage-length=
 602 Common RejectNegative Joined UInteger
 603 -fmessage-length=<number>       Limit diagnostics to <number> characters per line.  0 suppresses line-wrapping
 604
 605 fmodulo-sched
 606 Common Report Var(flag_modulo_sched)
 607 Perform SMS based modulo scheduling before the first scheduling pass
 608
 609 fmove-loop-invariants
 610 Common Report Var(flag_move_loop_invariants) Init(1)
 611 Move loop invariant computations out of loops
 612
 613 fmudflap
 614 Common RejectNegative Report Var(flag_mudflap)
 615 Add mudflap bounds-checking instrumentation for single-threaded program
 616
 617 fmudflapth
 618 Common RejectNegative Report VarExists Var(flag_mudflap,2)
 619 Add mudflap bounds-checking instrumentation for multi-threaded program
 620
 621 fmudflapir
 622 Common RejectNegative Report Var(flag_mudflap_ignore_reads)
 623 Ignore read operations when inserting mudflap instrumentation
 624
 625 freschedule-modulo-scheduled-loops
 626 Common Report Var(flag_resched_modulo_sched)
 627 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling
 628
 629 fnon-call-exceptions
 630 Common Report Var(flag_non_call_exceptions)
 631 Support synchronous non-call exceptions
 632
 633 fomit-frame-pointer
 634 Common Report Var(flag_omit_frame_pointer)
 635 When possible do not generate stack frames
 636
 637 foptimize-register-move
 638 Common Report Var(flag_regmove)
 639 Do the full register move optimization pass
 640
 641 foptimize-sibling-calls
 642 Common Report Var(flag_optimize_sibling_calls)
 643 Optimize sibling and tail recursive calls
 644
 645 fpre-ipa-mem-report
 646 Common Report Var(pre_ipa_mem_report)
 647 Report on memory allocation before interprocedural optimization
 648
 649 fpost-ipa-mem-report
 650 Common Report Var(post_ipa_mem_report)
 651 Report on memory allocation before interprocedural optimization
 652
 653 fpack-struct
 654 Common Report Var(flag_pack_struct)
 655 Pack structure members together without holes
 656
 657 fpack-struct=
 658 Common RejectNegative Joined UInteger
 659 -fpack-struct=<number>  Set initial maximum structure member alignment
 660
 661 fpcc-struct-return
 662 Common Report Var(flag_pcc_struct_return,1) VarExists
 663 Return small aggregates in memory, not registers
 664
 665 fpeel-loops
 666 Common Report Var(flag_peel_loops)
 667 Perform loop peeling
 668
 669 fpeephole
 670 Common Report Var(flag_no_peephole,0)
 671 Enable machine specific peephole optimizations
 672
 673 fpeephole2
 674 Common Report Var(flag_peephole2)
 675 Enable an RTL peephole pass before sched2
 676
 677 fPIC
 678 Common Report Var(flag_pic,2)
 679 Generate position-independent code if possible (large mode)
 680
 681 fPIE
 682 Common Report Var(flag_pie,2)
 683 Generate position-independent code for executables if possible (large mode)
 684
 685 fpic
 686 Common Report Var(flag_pic,1) VarExists
 687 Generate position-independent code if possible (small mode)
 688
 689 fpie
 690 Common Report Var(flag_pie,1) VarExists
 691 Generate position-independent code for executables if possible (small mode)
 692
 693 fprefetch-loop-arrays
 694 Common Report Var(flag_prefetch_loop_arrays)
 695 Generate prefetch instructions, if available, for arrays in loops
 696
 697 fprofile
 698 Common Report Var(profile_flag)
 699 Enable basic program profiling code
 700
 701 fprofile-arcs
 702 Common Report Var(profile_arc_flag)
 703 Insert arc-based program profiling code
 704
 705 fprofile-generate
 706 Common
 707 Enable common options for generating profile info for profile feedback directed optimizations
 708
 709 fprofile-use
 710 Common
 711 Enable common options for performing profile feedback directed optimizations
 712
 713 fprofile-values
 714 Common Report Var(flag_profile_values)
 715 Insert code to profile values of expressions
 716
 717 frandom-seed
 718 Common
 719
 720 frandom-seed=
 721 Common Joined RejectNegative
 722 -frandom-seed=<string>  Make compile reproducible using <string>
 723
 724 ; This switch causes the command line that was used to create an
 725 ; object file to be recorded into the object file.  The exact format
 726 ; of this recording is target and binary file format dependent.
 727 ; It is related to the -fverbose-asm switch, but that switch only
 728 ; records information in the assembler output file as comments, so
 729 ; they never reach the object file.
 730 frecord-gcc-switches
 731 Common Report Var(flag_record_gcc_switches)
 732 Record gcc command line switches in the object file.
 733
 734 freg-struct-return
 735 Common Report Var(flag_pcc_struct_return,0) VarExists
 736 Return small aggregates in registers
 737
 738 fregmove
 739 Common Report Var(flag_regmove)
 740 Enables a register move optimization
 741
 742 frename-registers
 743 Common Report Var(flag_rename_registers) Init(2)
 744 Perform a register renaming optimization pass
 745
 746 freorder-blocks
 747 Common Report Var(flag_reorder_blocks)
 748 Reorder basic blocks to improve code placement
 749
 750 freorder-blocks-and-partition
 751 Common Report Var(flag_reorder_blocks_and_partition)
 752 Reorder basic blocks and partition into hot and cold sections
 753
 754 freorder-functions
 755 Common Report Var(flag_reorder_functions)
 756 Reorder functions to improve code placement
 757
 758 frerun-cse-after-loop
 759 Common Report Var(flag_rerun_cse_after_loop) Init(2)
 760 Add a common subexpression elimination pass after loop optimizations
 761
 762 frerun-loop-opt
 763 Common
 764 Does nothing.  Preserved for backward compatibility.
 765
 766 frounding-math
 767 Common Report Var(flag_rounding_math)
 768 Disable optimizations that assume default FP rounding behavior
 769
 770 fsched-interblock
 771 Common Report Var(flag_schedule_interblock) Init(1)
 772 Enable scheduling across basic blocks
 773
 774 fsched-spec
 775 Common Report Var(flag_schedule_speculative) Init(1)
 776 Allow speculative motion of non-loads
 777
 778 fsched-spec-load
 779 Common Report Var(flag_schedule_speculative_load)
 780 Allow speculative motion of some loads
 781
 782 fsched-spec-load-dangerous
 783 Common Report Var(flag_schedule_speculative_load_dangerous)
 784 Allow speculative motion of more loads
 785
 786 fsched-verbose=
 787 Common RejectNegative Joined
 788 -fsched-verbose=<number>        Set the verbosity level of the scheduler
 789
 790 fsched2-use-superblocks
 791 Common Report Var(flag_sched2_use_superblocks)
 792 If scheduling post reload, do superblock scheduling
 793
 794 fsched2-use-traces
 795 Common Report Var(flag_sched2_use_traces)
 796 If scheduling post reload, do trace scheduling
 797
 798 fschedule-insns
 799 Common Report Var(flag_schedule_insns)
 800 Reschedule instructions before register allocation
 801
 802 fschedule-insns2
 803 Common Report Var(flag_schedule_insns_after_reload)
 804 Reschedule instructions after register allocation
 805
 806 ; sched_stalled_insns means that insns can be moved prematurely from the queue
 807 ; of stalled insns into the ready list.
 808 fsched-stalled-insns
 809 Common Report Var(flag_sched_stalled_insns)
 810 Allow premature scheduling of queued insns
 811
 812 fsched-stalled-insns=
 813 Common RejectNegative Joined UInteger
 814 -fsched-stalled-insns=<number>  Set number of queued insns that can be prematurely scheduled
 815
 816 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
 817 ; be examined for a dependency on a stalled insn that is candidate for
 818 ; premature removal from the queue of stalled insns into the ready list (has
 819 ; an effect only if the flag 'sched_stalled_insns' is set).
 820 fsched-stalled-insns-dep
 821 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1)
 822 Set dependence distance checking in premature scheduling of queued insns
 823
 824 fsched-stalled-insns-dep=
 825 Common RejectNegative Joined UInteger
 826 -fsched-stalled-insns-dep=<number>      Set dependence distance checking in premature scheduling of queued insns
 827
 828 fsection-anchors
 829 Common Report Var(flag_section_anchors)
 830 Access data in the same section from shared anchor points
 831
 832 frtl-abstract-sequences
 833 Common Report Var(flag_rtl_seqabstr)
 834 Perform sequence abstraction optimization on RTL
 835
 836 fsee
 837 Common Report Var(flag_see) Init(0)
 838 Eliminate redundant sign extensions using LCM.
 839
 840 fshow-column
 841 Common C ObjC C++ ObjC++ Report Var(flag_show_column) Init(1)
 842 Show column numbers in diagnostics, when available.  Default on
 843
 844 fsignaling-nans
 845 Common Report Var(flag_signaling_nans)
 846 Disable optimizations observable by IEEE signaling NaNs
 847
 848 fsigned-zeros
 849 Common Report Var(flag_signed_zeros) Init(1)
 850 Disable floating point optimizations that ignore the IEEE signedness of zero
 851
 852 fsingle-precision-constant
 853 Common Report Var(flag_single_precision_constant)
 854 Convert floating point constants to single precision constants
 855
 856 fsplit-ivs-in-unroller
 857 Common Report Var(flag_split_ivs_in_unroller) Init(1)
 858 Split lifetimes of induction variables when loops are unrolled
 859
 860 fvariable-expansion-in-unroller
 861 Common Report Var(flag_variable_expansion_in_unroller)
 862 Apply variable expansion when loops are unrolled
 863
 864 ; Emit code to probe the stack, to help detect stack overflow; also
 865 ; may cause large objects to be allocated dynamically.
 866 fstack-check
 867 Common Report Var(flag_stack_check)
 868 Insert stack checking code into the program
 869
 870 fstack-limit
 871 Common
 872
 873 fstack-limit-register=
 874 Common RejectNegative Joined
 875 -fstack-limit-register=<register>       Trap if the stack goes past <register>
 876
 877 fstack-limit-symbol=
 878 Common RejectNegative Joined
 879 -fstack-limit-symbol=<name>     Trap if the stack goes past symbol <name>
 880
 881 fstack-protector
 882 Common Report Var(flag_stack_protect, 1)
 883 Use propolice as a stack protection method
 884
 885 fstack-protector-all
 886 Common Report RejectNegative Var(flag_stack_protect, 2) VarExists
 887 Use a stack protection method for every function
 888
 889 fstrength-reduce
 890 Common
 891 Does nothing.  Preserved for backward compatibility.
 892
 893 ; Nonzero if we should do (language-dependent) alias analysis.
 894 ; Typically, this analysis will assume that expressions of certain
 895 ; types do not alias expressions of certain other types.  Only used
 896 ; if alias analysis (in general) is enabled.
 897 fstrict-aliasing
 898 Common Report Var(flag_strict_aliasing)
 899 Assume strict aliasing rules apply
 900
 901 fsyntax-only
 902 Common Report Var(flag_syntax_only)
 903 Check for syntax errors, then stop
 904
 905 ftest-coverage
 906 Common Report Var(flag_test_coverage)
 907 Create data files needed by \"gcov\"
 908
 909 fthread-jumps
 910 Common Report Var(flag_thread_jumps)
 911 Perform jump threading optimizations
 912
 913 ftime-report
 914 Common Report Var(time_report)
 915 Report the time taken by each compiler pass
 916
 917 ftls-model=
 918 Common Joined RejectNegative
 919 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec]      Set the default thread-local storage code generation model
 920
 921 ftoplevel-reorder
 922 Common Report Var(flag_toplevel_reorder) Init(1)
 923 Reorder top level functions, variables, and asms
 924
 925 ftracer
 926 Common Report Var(flag_tracer)
 927 Perform superblock formation via tail duplication
 928
 929 ; Zero means that floating-point math operations cannot generate a
 930 ; (user-visible) trap.  This is the case, for example, in nonstop
 931 ; IEEE 754 arithmetic.
 932 ftrapping-math
 933 Common Report Var(flag_trapping_math) Init(1)
 934 Assume floating-point operations can trap
 935
 936 ftrapv
 937 Common Report Var(flag_trapv)
 938 Trap for signed overflow in addition, subtraction and multiplication
 939
 940 ftree-ccp
 941 Common Report Var(flag_tree_ccp)
 942 Enable SSA-CCP optimization on trees
 943
 944 ftree-store-ccp
 945 Common Report Var(flag_tree_store_ccp)
 946 Enable SSA-CCP optimization for stores and loads
 947
 948 ftree-ch
 949 Common Report Var(flag_tree_ch)
 950 Enable loop header copying on trees
 951
 952 ftree-copyrename
 953 Common Report Var(flag_tree_copyrename)
 954 Replace SSA temporaries with better names in copies
 955
 956 ftree-copy-prop
 957 Common Report Var(flag_tree_copy_prop)
 958 Enable copy propagation on trees
 959
 960 ftree-store-copy-prop
 961 Common Report Var(flag_tree_store_copy_prop)
 962 Enable copy propagation for stores and loads
 963
 964 ftree-dce
 965 Common Report Var(flag_tree_dce)
 966 Enable SSA dead code elimination optimization on trees
 967
 968 ftree-dominator-opts
 969 Common Report Var(flag_tree_dom)
 970 Enable dominator optimizations
 971
 972 ftree-dse
 973 Common Report Var(flag_tree_dse)
 974 Enable dead store elimination
 975
 976 ftree-fre
 977 Common Report Var(flag_tree_fre)
 978 Enable Full Redundancy Elimination (FRE) on trees
 979
 980 ftree-loop-im
 981 Common Report Var(flag_tree_loop_im) Init(1)
 982 Enable loop invariant motion on trees
 983
 984 ftree-loop-linear
 985 Common Report Var(flag_tree_loop_linear)
 986 Enable linear loop transforms on trees
 987
 988 ftree-loop-ivcanon
 989 Common Report Var(flag_tree_loop_ivcanon) Init(1)
 990 Create canonical induction variables in loops
 991
 992 ftree-loop-optimize
 993 Common Report Var(flag_tree_loop_optimize) Init(1)
 994 Enable loop optimizations on tree level
 995
 996 ftree-pre
 997 Common Report Var(flag_tree_pre)
 998 Enable SSA-PRE optimization on trees
 999
1000 ftree-salias
1001 Common Report Var(flag_tree_salias)
1002 Perform structural alias analysis
1003
1004 ftree-sink
1005 Common Report Var(flag_tree_sink)
1006 Enable SSA code sinking on trees
1007
1008 ftree-sra
1009 Common Report Var(flag_tree_sra)
1010 Perform scalar replacement of aggregates
1011
1012 ftree-ter
1013 Common Report Var(flag_tree_ter)
1014 Replace temporary expressions in the SSA->normal pass
1015
1016 ftree-vrp
1017 Common Report Var(flag_tree_vrp) Init(0)
1018 Perform Value Range Propagation on trees
1019
1020 funit-at-a-time
1021 Common Report Var(flag_unit_at_a_time)
1022 Compile whole compilation unit at a time
1023
1024 funroll-loops
1025 Common Report Var(flag_unroll_loops)
1026 Perform loop unrolling when iteration count is known
1027
1028 funroll-all-loops
1029 Common Report Var(flag_unroll_all_loops)
1030 Perform loop unrolling for all loops
1031
1032 ; Nonzero means that loop optimizer may assume that the induction variables
1033 ; that control loops do not overflow and that the loops with nontrivial
1034 ; exit condition are not infinite
1035 funsafe-loop-optimizations
1036 Common Report Var(flag_unsafe_loop_optimizations)
1037 Allow loop optimizations to assume that the loops behave in normal way
1038
1039 ; Nonzero means that unsafe floating-point math optimizations are allowed
1040 ; for the sake of speed.  IEEE compliance is not guaranteed, and operations
1041 ; are allowed to assume that their arguments and results are "normal"
1042 ; (e.g., nonnegative for SQRT).
1043 funsafe-math-optimizations
1044 Common Report Var(flag_unsafe_math_optimizations)
1045 Allow math optimizations that may violate IEEE or ISO standards
1046
1047 funswitch-loops
1048 Common Report Var(flag_unswitch_loops)
1049 Perform loop unswitching
1050
1051 funwind-tables
1052 Common Report Var(flag_unwind_tables)
1053 Just generate unwind tables for exception handling
1054
1055 fvar-tracking
1056 Common Report Var(flag_var_tracking) VarExists
1057 Perform variable tracking
1058
1059 ftree-vectorize
1060 Common Report Var(flag_tree_vectorize)
1061 Enable loop vectorization on trees
1062
1063 ftree-vect-loop-version
1064 Common Report Var(flag_tree_vect_loop_version) Init(1)
1065 Enable loop versioning when doing loop vectorization on trees
1066
1067 ftree-vectorizer-verbose=
1068 Common RejectNegative Joined
1069 -ftree-vectorizer-verbose=<number>      Set the verbosity level of the vectorizer
1070
1071 ; -fverbose-asm causes extra commentary information to be produced in
1072 ; the generated assembly code (to make it more readable).  This option
1073 ; is generally only of use to those who actually need to read the
1074 ; generated assembly code (perhaps while debugging the compiler itself).
1075 ; -fno-verbose-asm, the default, causes the extra information
1076 ; to not be added and is useful when comparing two assembler files.
1077 fverbose-asm
1078 Common Report Var(flag_verbose_asm)
1079 Add extra commentary to assembler output
1080
1081 fvisibility=
1082 Common Joined RejectNegative
1083 -fvisibility=[default|internal|hidden|protected]        Set the default symbol visibility
1084
1085
1086 fvpt
1087 Common Report Var(flag_value_profile_transformations)
1088 Use expression value profiles in optimizations
1089
1090 fweb
1091 Common Report Var(flag_web) Init(2)
1092 Construct webs and split unrelated uses of single variable
1093
1094 fwhole-program
1095 Common Report Var(flag_whole_program) Init(0)
1096 Perform whole program optimizations
1097
1098 fwrapv
1099 Common Report Var(flag_wrapv)
1100 Assume signed arithmetic overflow wraps around
1101
1102 fzero-initialized-in-bss
1103 Common Report Var(flag_zero_initialized_in_bss) Init(1)
1104 Put zero initialized data in the bss section
1105
1106 g
1107 Common JoinedOrMissing
1108 Generate debug information in default format
1109
1110 gcoff
1111 Common JoinedOrMissing Negative(gdwarf-2)
1112 Generate debug information in COFF format
1113
1114 gdwarf-2
1115 Common JoinedOrMissing Negative(gstabs)
1116 Generate debug information in DWARF v2 format
1117
1118 ggdb
1119 Common JoinedOrMissing
1120 Generate debug information in default extended format
1121
1122 gstabs
1123 Common JoinedOrMissing Negative(gstabs+)
1124 Generate debug information in STABS format
1125
1126 gstabs+
1127 Common JoinedOrMissing Negative(gvms)
1128 Generate debug information in extended STABS format
1129
1130 gvms
1131 Common JoinedOrMissing Negative(gxcoff)
1132 Generate debug information in VMS format
1133
1134 gxcoff
1135 Common JoinedOrMissing Negative(gxcoff+)
1136 Generate debug information in XCOFF format
1137
1138 gxcoff+
1139 Common JoinedOrMissing Negative(gcoff)
1140 Generate debug information in extended XCOFF format
1141
1142 o
1143 Common Joined Separate
1144 -o <file>       Place output into <file>
1145
1146 p
1147 Common Var(profile_flag)
1148 Enable function profiling
1149
1150 pedantic
1151 Common Var(pedantic)
1152 Issue warnings needed for strict compliance to the standard
1153
1154 pedantic-errors
1155 Common
1156 Like -pedantic but issue them as errors
1157
1158 quiet
1159 Common Var(quiet_flag)
1160 Do not display functions compiled or elapsed time
1161
1162 version
1163 Common Var(version_flag)
1164 Display the compiler's version
1165
1166 w
1167 Common Var(inhibit_warnings)
1168 Suppress warnings
1169
1170 ; This comment is to ensure we retain the blank line above.