gcc/common.opt

   1 ; Options for the language- and target-independent parts of the compiler.
   2 ; Copyright (C) 2003, 2004 Free Software Foundation, Inc.
   3 ;
   4 ; This file is part of GCC.
   5 ;
   6 ; GCC is free software; you can redistribute it and/or modify it under
   7 ; the terms of the GNU General Public License as published by the Free
   8 ; Software Foundation; either version 2, or (at your option) any later
   9 ; version.
  10 ;
  11 ; GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 ; WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 ; FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 ; for more details.
  15 ;
  16 ; You should have received a copy of the GNU General Public License
  17 ; along with GCC; see the file COPYING.  If not, write to the Free
  18 ; Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  19 ; 02111-1307, USA.
  20
  21 ; See c.opt for a description of this file's format.
  22
  23 ; Please try to keep this file in ASCII collating order.
  24
  25 -help
  26 Common
  27 Display this information
  28
  29 -param
  30 Common Separate
  31 --param <param>=<value> Set paramter <param> to value.  See below for a complete list of parameters
  32
  33 -target-help
  34 Common
  35
  36 -version
  37 Common
  38
  39 G
  40 Common Joined Separate UInteger
  41 -G<number>      Put global and static data smaller than <number> bytes into a special section (on some targets)
  42
  43 O
  44 Common JoinedOrMissing
  45 -O<number>      Set optimization level to <number>
  46
  47 Os
  48 Common
  49 Optimize for space rather than speed
  50
  51 W
  52 Common RejectNegative
  53 This switch is deprecated; use -Wextra instead
  54
  55 Waggregate-return
  56 Common
  57 Warn about returning structures, unions or arrays
  58
  59 Wcast-align
  60 Common
  61 Warn about pointer casts which increase alignment
  62
  63 Wdeprecated-declarations
  64 Common
  65 Warn about uses of __attribute__((deprecated)) declarations
  66
  67 Wdisabled-optimization
  68 Common
  69 Warn when an optimization pass is disabled
  70
  71 Werror
  72 Common
  73 Treat all warnings as errors
  74
  75 Wextra
  76 Common
  77 Print extra (possibly unwanted) warnings
  78
  79 Winline
  80 Common
  81 Warn when an inlined function cannot be inlined
  82
  83 Wlarger-than-
  84 Common RejectNegative Joined UInteger
  85 -Wlarger-than-<number>  Warn if an object is larger than <number> bytes
  86
  87 Wmissing-noreturn
  88 Common
  89 Warn about functions which might be candidates for __attribute__((noreturn))
  90
  91 Wpacked
  92 Common
  93 Warn when the packed attribute has no effect on struct layout
  94
  95 Wpadded
  96 Common
  97 Warn when padding is required to align structure members
  98
  99 Wshadow
 100 Common
 101 Warn when one local variable shadows another
 102
 103 Wstrict-aliasing
 104 Common
 105 Warn about code which might break strict aliasing rules
 106
 107 Wswitch
 108 Common
 109 Warn about enumerated switches, with no default, missing a case
 110
 111 Wswitch-default
 112 Common
 113 Warn about enumerated switches missing a \"default:\" statement
 114
 115 Wswitch-enum
 116 Common
 117 Warn about all enumerated switches missing a specific case
 118
 119 Wsystem-headers
 120 Common
 121 Do not suppress warnings from system headers
 122
 123 Wuninitialized
 124 Common
 125 Warn about uninitialized automatic variables
 126
 127 Wunreachable-code
 128 Common
 129 Warn about code that will never be executed
 130
 131 Wunused
 132 Common
 133 Enable all -Wunused- warnings
 134
 135 Wunused-function
 136 Common
 137 Warn when a function is unused
 138
 139 Wunused-label
 140 Common
 141 Warn when a label is unused
 142
 143 Wunused-parameter
 144 Common
 145 Warn when a function parameter is unused
 146
 147 Wunused-value
 148 Common
 149 Warn when an expression value is unused
 150
 151 Wunused-variable
 152 Common
 153 Warn when a variable is unused
 154
 155 aux-info
 156 Common Separate
 157 -aux-info <file>        Emit declaration information into <file>
 158
 159 aux-info=
 160 Common Joined
 161
 162 auxbase
 163 Common Separate
 164
 165 auxbase-strip
 166 Common Separate
 167
 168 d
 169 Common Joined
 170 -d<letters>     Enable dumps from specific passes of the compiler
 171
 172 dumpbase
 173 Common Separate
 174 -dumpbase <file>        Set the file basename to be used for dumps
 175
 176 fPIC
 177 Common
 178
 179 fPIE
 180 Common
 181
 182 fabi-version=
 183 Common Joined UInteger
 184
 185 falign-functions
 186 Common
 187 Align the start of functions
 188
 189 falign-functions=
 190 Common RejectNegative Joined UInteger
 191
 192 falign-jumps
 193 Common
 194 Align labels which are only reached by jumping
 195
 196 falign-jumps=
 197 Common RejectNegative Joined UInteger
 198
 199 falign-labels
 200 Common
 201 Align all labels
 202
 203 falign-labels=
 204 Common RejectNegative Joined UInteger
 205
 206 falign-loops
 207 Common
 208 Align the start of loops
 209
 210 falign-loops=
 211 Common RejectNegative Joined UInteger
 212
 213 fargument-alias
 214 Common
 215 Specify that arguments may alias each other and globals
 216
 217 fargument-noalias
 218 Common
 219 Assume arguments may alias globals but not each other
 220
 221 fargument-noalias-global
 222 Common
 223 Assume arguments alias neither each other nor globals
 224
 225 fasynchronous-unwind-tables
 226 Common
 227 Generate unwind tables that are exact at each instruction boundary
 228
 229 fbounds-check
 230 Common
 231 Generate code to check bounds before indexing arrays
 232
 233 fbranch-count-reg
 234 Common
 235 Replace add, compare, branch with branch on count register
 236
 237 fbranch-probabilities
 238 Common
 239 Use profiling information for branch probabilities
 240
 241 fbranch-target-load-optimize
 242 Common
 243 Perform branch target load optimization before prologue / epilogue threading
 244
 245 fbranch-target-load-optimize2
 246 Common
 247 Perform branch target load optimization after prologue / epilogue threading
 248
 249 fbtr-bb-exclusive
 250 Common
 251 Restrict target load migration not to re-use registers in any basic block
 252
 253 fcall-saved-
 254 Common Joined RejectNegative
 255 -fcall-saved-<register> Mark <register> as being preserved across functions
 256
 257 fcall-used-
 258 Common Joined RejectNegative
 259 -fcall-used-<register>  Mark <register> as being corrupted by function calls
 260
 261 fcaller-saves
 262 Common
 263 Save registers around function calls
 264
 265 fcommon
 266 Common
 267 Do not put uninitialized globals in the common section
 268
 269 fcprop-registers
 270 Common
 271 Perform a register copy-propagation optimization pass
 272
 273 fcrossjumping
 274 Common
 275 Perform cross-jumping optimization
 276
 277 fcse-follow-jumps
 278 Common
 279 When running CSE, follow jumps to their targets
 280
 281 fcse-skip-blocks
 282 Common
 283 When running CSE, follow conditional jumps
 284
 285 fdata-sections
 286 Common
 287 Place data items into their own section
 288
 289 fdefer-pop
 290 Common
 291 Defer popping functions args from stack until later
 292
 293 fdelayed-branch
 294 Common
 295 Attempt to fill delay slots of branch instructions
 296
 297 fdelete-null-pointer-checks
 298 Common
 299 Delete useless null pointer checks
 300
 301 fdiagnostics-show-location=
 302 Common Joined RejectNegative
 303 -fdiagnostics-show-location=[once|every-line]   How often to emit source location at the beginning of line-wrapped diagnostics
 304
 305 fdump-unnumbered
 306 Common
 307 Suppress output of instruction numbers and line number notes in debugging dumps
 308
 309 feliminate-dwarf2-dups
 310 Common
 311 Perform DWARF2 duplicate elimination
 312
 313 feliminate-unused-debug-symbols
 314 Common
 315 Perform unused type elimination in debug info
 316
 317 feliminate-unused-debug-types
 318 Common
 319 Perform unused type elimination in debug info
 320
 321 fexceptions
 322 Common
 323 Enable exception handling
 324
 325 fexpensive-optimizations
 326 Common
 327 Perform a number of minor, expensive optimizations
 328
 329 ffast-math
 330 Common
 331
 332 ffinite-math-only
 333 Common
 334 Assume no NaNs or infinities are generated
 335
 336 ffixed-
 337 Common Joined RejectNegative
 338 -ffixed-<register>      Mark <register> as being unavailable to the compiler
 339
 340 ffloat-store
 341 Common
 342 Do not store floats in registers
 343
 344 fforce-addr
 345 Common
 346 Copy memory address constants into registers before use
 347
 348 fforce-mem
 349 Common
 350 Copy memory operands into registers before use
 351
 352 ffunction-cse
 353 Common
 354 Allow function addresses to be held in registers
 355
 356 ffunction-sections
 357 Common
 358 Place each function into its own section
 359
 360 fgcse
 361 Common
 362 Perform global common subexpression elimination
 363
 364 fgcse-lm
 365 Common
 366 Perform enhanced load motion during global common subexpression elimination
 367
 368 fgcse-sm
 369 Common
 370 Perform store motion after global common subexpression elimination
 371
 372 fgcse-las
 373 Common
 374 Perform redundant load after store elimination in global common subexpression
 375 elimination
 376
 377 fgcse-after-reload
 378 Common
 379 Perform global common subexpression elimination after register allocation
 380 has finished.
 381
 382 fguess-branch-probability
 383 Common
 384 Enable guessing of branch probabilities
 385
 386 fident
 387 Common
 388 Process #ident directives
 389
 390 fif-conversion
 391 Common
 392 Perform conversion of conditional jumps to branchless equivalents
 393
 394 fif-conversion2
 395 Common
 396 Perform conversion of conditional jumps to conditional execution
 397
 398 finhibit-size-directive
 399 Common
 400 Do not generate .size directives
 401
 402 finline
 403 Common
 404 Pay attention to the \"inline\" keyword
 405
 406 finline-functions
 407 Common
 408 Integrate simple functions into their callers
 409
 410 finline-limit-
 411 Common RejectNegative Joined UInteger
 412
 413 finline-limit=
 414 Common RejectNegative Joined UInteger
 415 -finline-limit=<number> Limit the size of inlined functions to <number>
 416
 417 finstrument-functions
 418 Common
 419 Instrument function entry and exit with profiling calls
 420
 421 fkeep-inline-functions
 422 Common
 423 Generate code for functions even if they are fully inlined
 424
 425 fkeep-static-consts
 426 Common
 427 Emit static const variables even if they are not used
 428
 429 fleading-underscore
 430 Common
 431 Give external symbols a leading underscore
 432
 433 floop-optimize
 434 Common
 435 Perform loop optimizations
 436
 437 fmath-errno
 438 Common
 439 Set errno after built-in math functions
 440
 441 fmem-report
 442 Common
 443 Report on permanent memory allocation
 444
 445 fmerge-all-constants
 446 Common
 447 Attempt to merge identical constants and constant variables
 448
 449 fmerge-constants
 450 Common
 451 Attempt to merge identical constants across compilation units
 452
 453 fmessage-length=
 454 Common RejectNegative Joined UInteger
 455 -fmessage-length=<number>       Limit diagnostics to <number> characters per line.  0 suppresses line-wrapping
 456
 457 fmove-all-movables
 458 Common
 459 Force all loop invariant computations out of loops
 460
 461 fnew-ra
 462 Common
 463 Use graph-coloring register allocation
 464
 465 fnon-call-exceptions
 466 Common
 467 Support synchronous non-call exceptions
 468
 469 fold-unroll-loops
 470 Common
 471 Perform loop unrolling when iteration count is known
 472
 473 fold-unroll-all-loops
 474 Common
 475 Perform loop unrolling for all loops
 476
 477 fomit-frame-pointer
 478 Common
 479 When possible do not generate stack frames
 480
 481 foptimize-register-move
 482 Common
 483 Do the full register move optimization pass
 484
 485 foptimize-sibling-calls
 486 Common
 487 Optimize sibling and tail recursive calls
 488
 489 fpack-struct
 490 Common
 491 Pack structure members together without holes
 492
 493 fpcc-struct-return
 494 Common
 495 Return small aggregates in memory, not registers
 496
 497 fpeel-loops
 498 Common
 499 Perform loop peeling
 500
 501 fpeephole
 502 Common
 503 Enable machine specific peephole optimizations
 504
 505 fpeephole2
 506 Common
 507 Enable an RTL peephole pass before sched2
 508
 509 fpic
 510 Common
 511 Generate position-independent code if possible
 512
 513 fpie
 514 Common
 515 Generate position-independent code for executables if possible
 516
 517 fprefetch-loop-arrays
 518 Common
 519 Generate prefetch instructions, if available, for arrays in loops
 520
 521 fprofile
 522 Common
 523 Enable basic program profiling code
 524
 525 fprofile-arcs
 526 Common
 527 Insert arc-based program profiling code
 528
 529 fprofile-generate
 530 Common
 531 Enable common options for generating profile info for profile feedback directed optimizations
 532
 533 fprofile-use
 534 Common
 535 Enable common options for performing profile feedback directed optimizations
 536
 537 fprofile-values
 538 Common
 539 Insert code to profile values of expressions
 540
 541 frandom-seed
 542 Common
 543
 544 frandom-seed=
 545 Common Joined RejectNegative
 546 -frandom-seed=<string>  Make compile reproducible using <string>
 547
 548 freduce-all-givs
 549 Common
 550 Strength reduce all loop general induction variables
 551
 552 freg-struct-return
 553 Common
 554 Return small aggregates in registers
 555
 556 fregmove
 557 Common
 558 Enables a register move optimization
 559
 560 frename-registers
 561 Common
 562 Perform a register renaming optimization pass
 563
 564 freorder-blocks
 565 Common
 566 Reorder basic blocks to improve code placement
 567
 568 freorder-functions
 569 Common
 570 Reorder functions to improve code placement
 571
 572 frerun-cse-after-loop
 573 Common
 574 Add a common subexpression elimination pass after loop optimizations
 575
 576 frerun-loop-opt
 577 Common
 578 Run the loop optimizer twice
 579
 580 frounding-math
 581 Common
 582 Disable optimizations that assume default FP rounding behavior
 583
 584 fsched-interblock
 585 Common
 586 Enable scheduling across basic blocks
 587
 588 fsched-spec
 589 Common
 590 Allow speculative motion of non-loads
 591
 592 fsched-spec-load
 593 Common
 594 Allow speculative motion of some loads
 595
 596 fsched-spec-load-dangerous
 597 Common
 598 Allow speculative motion of more loads
 599
 600 fsched-verbose=
 601 Common RejectNegative Joined
 602 -fsched-verbose=<number>        Set the verbosity level of the scheduler
 603
 604 fsched2-use-superblocks
 605 Common
 606 If scheduling post reload, do superblock scheduling
 607
 608 fsched2-use-traces
 609 Common
 610 If scheduling post reload, do trace scheduling
 611
 612 fschedule-insns
 613 Common
 614 Reschedule instructions before register allocation
 615
 616 fschedule-insns2
 617 Common
 618 Reschedule instructions after register allocation
 619
 620 fsched-stalled-insns
 621 Common
 622 Allow premature scheduling of queued insns
 623
 624 fsched-stalled-insns=
 625 Common RejectNegative Joined UInteger
 626 -fsched-stalled-insns=<number>       Set number of queued insns that can be prematurely scheduled
 627
 628 fsched-stalled-insns-dep
 629 Common
 630 Set dependence distance checking in premature scheduling of queued insns
 631
 632 fsched-stalled-insns-dep=
 633 Common RejectNegative Joined UInteger
 634 -fsched-stalled-insns-dep=<number>   Set dependence distance checking in premature scheduling of queued insns
 635
 636 fshared-data
 637 Common
 638 Mark data as shared rather than private
 639
 640 fsignaling-nans
 641 Common
 642 Disable optimizations observable by IEEE signaling NaNs
 643
 644 fsingle-precision-constant
 645 Common
 646 Convert floating point constants to single precision constants
 647
 648 fstack-check
 649 Common
 650 Insert stack checking code into the program
 651
 652 fstack-limit
 653 Common
 654
 655 fstack-limit-register=
 656 Common RejectNegative Joined
 657 -fstack-limit-register=<register>       Trap if the stack goes past <register>
 658
 659 fstack-limit-symbol=
 660 Common RejectNegative Joined
 661 -fstack-limit-symbol=<name>     Trap if the stack goes past symbol <name>
 662
 663 fstrength-reduce
 664 Common
 665 Perform strength reduction optimizations
 666
 667 fstrict-aliasing
 668 Common
 669 Assume strict aliasing rules apply
 670
 671 fsyntax-only
 672 Common
 673 Check for syntax errors, then stop
 674
 675 ftest-coverage
 676 Common
 677 Create data files needed by \"gcov\"
 678
 679 fthread-jumps
 680 Common
 681 Perform jump threading optimizations
 682
 683 ftime-report
 684 Common
 685 Report the time taken by each compiler pass
 686
 687 ftls-model=
 688 Common Joined RejectNegative
 689 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec]      Set the default thread-local storage code generation model
 690
 691 ftracer
 692 Common
 693 Perform superblock formation via tail duplication
 694
 695 ftrapping-math
 696 Common
 697 Assume floating-point operations can trap
 698
 699 ftrapv
 700 Common
 701 Trap for signed overflow in addition, subtraction and multiplication
 702
 703 funit-at-a-time
 704 Common
 705 Compile whole compilation unit at a time
 706
 707 funroll-loops
 708 Common
 709 Perform loop unrolling when iteration count is known
 710
 711 funroll-all-loops
 712 Common
 713 Perform loop unrolling for all loops
 714
 715 funsafe-math-optimizations
 716 Common
 717 Allow math optimizations that may violate IEEE or ISO standards
 718
 719 funswitch-loops
 720 Common
 721 Perform loop unswitching
 722
 723 funwind-tables
 724 Common
 725 Just generate unwind tables for exception handling
 726
 727 fvar-tracking
 728 Common
 729 Perform variable tracking
 730
 731 fverbose-asm
 732 Common
 733 Add extra commentary to assembler output
 734
 735 fvpt
 736 Common
 737 Use expression value profiles in optimizations
 738
 739 fweb
 740 Common
 741 Construct webs and split unrelated uses of single variable
 742
 743 fwrapv
 744 Common
 745 Assume signed arithmetic overflow wraps around
 746
 747 fzero-initialized-in-bss
 748 Common
 749 Put zero initialized data in the bss section
 750
 751 g
 752 Common JoinedOrMissing
 753 Generate debug information in default format
 754
 755 gcoff
 756 Common JoinedOrMissing
 757 Generate debug information in COFF format
 758
 759 gdwarf-2
 760 Common JoinedOrMissing
 761 Generate debug information in DWARF v2 format
 762
 763 ggdb
 764 Common JoinedOrMissing
 765 Generate debug information in default extended format
 766
 767 gstabs
 768 Common JoinedOrMissing
 769 Generate debug information in STABS format
 770
 771 gstabs+
 772 Common JoinedOrMissing
 773 Generate debug information in extended STABS format
 774
 775 gvms
 776 Common JoinedOrMissing
 777 Generate debug information in VMS format
 778
 779 gxcoff
 780 Common JoinedOrMissing
 781 Generate debug information in XCOFF format
 782
 783 gxcoff+
 784 Common JoinedOrMissing
 785 Generate debug information in extended XCOFF format
 786
 787 m
 788 Common Joined
 789
 790 o
 791 Common Joined Separate
 792 -o <file>       Place output into <file>
 793
 794 p
 795 Common
 796 Enable function profiling
 797
 798 pedantic
 799 Common
 800 Issue warnings needed for strict compliance to the standard
 801
 802 pedantic-errors
 803 Common
 804 Like -pedantic but issue them as errors
 805
 806 quiet
 807 Common
 808 Do not display functions compiled or elapsed time
 809
 810 version
 811 Common
 812 Display the compiler's version
 813
 814 w
 815 Common
 816 Suppress warnings
 817
 818 ; This comment is to ensure we retain the blank line above.