1 ; Options for the language- and target-independent parts of the compiler.
3 ; Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009
4 ; Free Software Foundation, Inc.
6 ; This file is part of GCC.
8 ; GCC is free software; you can redistribute it and/or modify it under
9 ; the terms of the GNU General Public License as published by the Free
10 ; Software Foundation; either version 3, or (at your option) any later
13 ; GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 ; WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 ; FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 ; You should have received a copy of the GNU General Public License
19 ; along with GCC; see the file COPYING3. If not see
20 ; <http://www.gnu.org/licenses/>.
22 ; See the GCC internals manual (options.texi) for a description of this file's format.
24 ; Please try to keep this file in ASCII collating order.
28 Display this information
32 --help=<class> Display descriptions of a specific class of options. <class> is one or more of optimizers, target, warnings, undocumented, params
36 Alias for --help=target
38 ;; The following four entries are to work around the gcc driver
39 ;; program's insatiable desire to turn options starting with a
40 ;; double dash (--) into options starting with a dash f (-f).
55 --param <param>=<value> Set parameter <param> to value. See below for a complete list of parameters
61 Common Joined Separate UInteger
62 -G<number> Put global and static data smaller than <number> bytes into a special section (on some targets)
65 Common JoinedOrMissing Optimization
66 -O<number> Set optimization level to <number>
70 Optimize for space rather than speed
73 Common RejectNegative Var(extra_warnings) Warning
74 This switch is deprecated; use -Wextra instead
77 Common Var(warn_aggregate_return) Warning
78 Warn about returning structures, unions or arrays
81 Common Var(warn_array_bounds) Warning
82 Warn if an array is accessed out of bounds
85 Common Var(warn_attributes) Init(1) Warning
86 Warn about inappropriate attribute usage
89 Common Var(warn_cast_align) Warning
90 Warn about pointer casts which increase alignment
92 Wdeprecated-declarations
93 Common Var(warn_deprecated_decl) Init(1) Warning
94 Warn about uses of __attribute__((deprecated)) declarations
96 Wdisabled-optimization
97 Common Var(warn_disabled_optimization) Warning
98 Warn when an optimization pass is disabled
101 Common Var(warnings_are_errors)
102 Treat all warnings as errors
106 Treat specified warning as error
109 Common Var(extra_warnings) Warning
110 Print extra (possibly unwanted) warnings
113 Common Var(flag_fatal_errors)
114 Exit on the first error occurred
117 Common RejectNegative Joined UInteger
118 -Wframe-larger-than=<number> Warn if a function's stack frame requires more than <number> bytes
121 Common Var(warn_inline) Warning
122 Warn when an inlined function cannot be inlined
125 Common RejectNegative Joined UInteger Warning
128 Common RejectNegative Joined UInteger Warning
129 -Wlarger-than=<number> Warn if an object is larger than <number> bytes
131 Wunsafe-loop-optimizations
132 Common Var(warn_unsafe_loop_optimizations) Warning
133 Warn if the loop cannot be optimized due to nontrivial assumptions.
136 Common Var(warn_missing_noreturn) Warning
137 Warn about functions which might be candidates for __attribute__((noreturn))
140 Common Var(warn_mudflap) Init(1) Warning
141 Warn about constructs not instrumented by -fmudflap
144 Common Var(warn_overflow) Init(1) Warning
145 Warn about overflow in arithmetic expressions
148 Common Var(warn_packed) Warning
149 Warn when the packed attribute has no effect on struct layout
152 Common Var(warn_padded) Warning
153 Warn when padding is required to align structure members
156 Common Var(warn_shadow) Warning
157 Warn when one local variable shadows another
160 Common Var(warn_stack_protect) Warning
161 Warn when not issuing stack smashing protection for some reason
165 Warn about code which might break strict aliasing rules
168 Common Joined UInteger Var(warn_strict_aliasing) Init(-1) Warning
169 Warn about code which might break strict aliasing rules
173 Warn about optimizations that assume that signed overflow is undefined
176 Common Joined UInteger Var(warn_strict_overflow) Init(-1) Warning
177 Warn about optimizations that assume that signed overflow is undefined
180 Common Var(warn_switch) Warning
181 Warn about enumerated switches, with no default, missing a case
184 Common Var(warn_switch_default) Warning
185 Warn about enumerated switches missing a \"default:\" statement
188 Common Var(warn_switch_enum) Warning
189 Warn about all enumerated switches missing a specific case
192 Common Var(warn_system_headers) Warning
193 Do not suppress warnings from system headers
196 Common Var(warn_type_limits) Init(-1) Warning
197 Warn if a comparison is always true or always false due to the limited range of the data type
200 Common Var(warn_uninitialized) Init(-1) Warning
201 Warn about uninitialized automatic variables
204 Common Var(warn_notreached) Warning
205 Warn about code that will never be executed
208 Common Var(warn_unused) Init(0) Warning
209 Enable all -Wunused- warnings
212 Common Var(warn_unused_function) Init(-1) Warning
213 Warn when a function is unused
216 Common Var(warn_unused_label) Init(-1) Warning
217 Warn when a label is unused
220 Common Var(warn_unused_parameter) Init(-1) Warning
221 Warn when a function parameter is unused
224 Common Var(warn_unused_value) Init(-1) Warning
225 Warn when an expression value is unused
228 Common Var(warn_unused_variable) Init(-1) Warning
229 Warn when a variable is unused
232 Common RejectNegative Var(warn_coverage_mismatch) Warning
233 Warn instead of error in case profiles in -fprofile-use do not match
237 -aux-info <file> Emit declaration information into <file>
250 -d<letters> Enable dumps from specific passes of the compiler
254 -dumpbase <file> Set the file basename to be used for dumps
256 ; The version of the C++ ABI in use. The following values are allowed:
258 ; 0: The version of the ABI believed most conformant with the C++ ABI
259 ; specification. This ABI may change as bugs are discovered and fixed.
260 ; Therefore, 0 will not necessarily indicate the same ABI in different
263 ; 1: The version of the ABI first used in G++ 3.2.
265 ; 2: The version of the ABI first used in G++ 3.4.
267 ; Additional positive integers will be assigned as new versions of
268 ; the ABI become the default version of the ABI.
270 Common Joined UInteger Var(flag_abi_version) Init(2)
273 Common Report Var(align_functions,0) Optimization UInteger
274 Align the start of functions
277 Common RejectNegative Joined UInteger
280 Common Report Var(align_jumps,0) Optimization UInteger
281 Align labels which are only reached by jumping
284 Common RejectNegative Joined UInteger
287 Common Report Var(align_labels,0) Optimization UInteger
291 Common RejectNegative Joined UInteger
294 Common Report Var(align_loops) Optimization UInteger
295 Align the start of loops
298 Common RejectNegative Joined UInteger
300 ; This flag is only tested if alias checking is enabled.
301 ; 0 if pointer arguments may alias each other. True in C.
302 ; 1 if pointer arguments may not alias each other but may alias
304 ; 2 if pointer arguments may not alias each other and may not
305 ; alias global variables.
306 ; 3 if pointer arguments may not alias anything. True in Fortran.
307 ; Set by the front end.
309 Common Report Var(flag_argument_noalias,0) Optimization
310 Specify that arguments may alias each other and globals
313 Common Report Var(flag_argument_noalias,1) VarExists Optimization
314 Assume arguments may alias globals but not each other
316 fargument-noalias-global
317 Common Report Var(flag_argument_noalias,2) VarExists Optimization
318 Assume arguments alias neither each other nor globals
320 fargument-noalias-anything
321 Common Report Var(flag_argument_noalias,3) VarExists Optimization
322 Assume arguments alias no other storage
324 fasynchronous-unwind-tables
325 Common Report Var(flag_asynchronous_unwind_tables) Optimization
326 Generate unwind tables that are exact at each instruction boundary
329 Common Report Var(flag_auto_inc_dec) Init(1)
330 Generate auto-inc/dec instructions
332 ; -fcheck-bounds causes gcc to generate array bounds checks.
333 ; For C, C++ and ObjC: defaults off.
334 ; For Java: defaults to on.
335 ; For Fortran: defaults to off.
337 Common Report Var(flag_bounds_check)
338 Generate code to check bounds before indexing arrays
341 Common Report Var(flag_branch_on_count_reg) Init(1) Optimization
342 Replace add, compare, branch with branch on count register
344 fbranch-probabilities
345 Common Report Var(flag_branch_probabilities) Optimization
346 Use profiling information for branch probabilities
348 fbranch-target-load-optimize
349 Common Report Var(flag_branch_target_load_optimize) Optimization
350 Perform branch target load optimization before prologue / epilogue threading
352 fbranch-target-load-optimize2
353 Common Report Var(flag_branch_target_load_optimize2) Optimization
354 Perform branch target load optimization after prologue / epilogue threading
357 Common Report Var(flag_btr_bb_exclusive) Optimization
358 Restrict target load migration not to re-use registers in any basic block
361 Common Joined RejectNegative
362 -fcall-saved-<register> Mark <register> as being preserved across functions
365 Common Joined RejectNegative
366 -fcall-used-<register> Mark <register> as being corrupted by function calls
368 ; Nonzero for -fcaller-saves: allocate values in regs that need to
369 ; be saved across function calls, if that produces overall better code.
370 ; Optional now, so people can test it.
372 Common Report Var(flag_caller_saves) Optimization
373 Save registers around function calls
376 Common Report Var(flag_check_data_deps)
377 Compare the results of several data dependence analyzers.
380 Common Report Var(flag_no_common,0) Optimization
381 Do not put uninitialized globals in the common section
384 Common Var(flag_conserve_stack) Optimization
385 Do not perform optimizations increasing noticeably stack usage
388 Common JoinedOrMissing RejectNegative Var(flag_compare_debug_opt)
389 -fcompare-debug[=<opts>] Compile with and without e.g. -gtoggle, and compare the final-insns dump
391 fcompare-debug-second
392 Common RejectNegative Var(flag_compare_debug)
393 Run only the second compilation of -fcompare-debug
396 Common Report Var(flag_cprop_registers) Optimization
397 Perform a register copy-propagation optimization pass
400 Common Report Var(flag_crossjumping) Optimization
401 Perform cross-jumping optimization
404 Common Report Var(flag_cse_follow_jumps) Optimization
405 When running CSE, follow jumps to their targets
409 Does nothing. Preserved for backward compatibility.
412 Common Report Var(flag_cx_limited_range) Optimization
413 Omit range reduction step when performing complex division
416 Common Report Var(flag_cx_fortran_rules) Optimization
417 Complex multiplication and division follow Fortran rules
420 Common Report Var(flag_data_sections) Optimization
421 Place data items into their own section
425 List all available debugging counters with their limits and counts.
428 Common RejectNegative Joined
429 -fdbg-cnt=<counter>:<limit>[,<counter>:<limit>,...] Set the debug counter limit.
432 Common Joined RejectNegative
433 Map one directory name to another in debug information
435 ; Nonzero for -fdefer-pop: don't pop args after each function call
436 ; instead save them up to pop many calls' args with one insns.
438 Common Report Var(flag_defer_pop) Optimization
439 Defer popping functions args from stack until later
442 Common Report Var(flag_delayed_branch) Optimization
443 Attempt to fill delay slots of branch instructions
445 fdelete-null-pointer-checks
446 Common Report Var(flag_delete_null_pointer_checks) Init(1) Optimization
447 Delete useless null pointer checks
449 fdiagnostics-show-location=
450 Common Joined RejectNegative
451 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics
453 fdiagnostics-show-option
455 Amend appropriate diagnostic messages with the command line option that controls them
458 Common Joined RejectNegative
459 -fdump-<type> Dump various compiler internals to a file
462 Common RejectNegative Joined Var(flag_dump_final_insns)
463 -fdump-final-insns=filename Dump to filename the insns at the end of translation
466 Common Report Var(flag_dump_noaddr)
467 Suppress output of addresses in debugging dumps
470 Common Report Var(flag_dump_unnumbered) VarExists
471 Suppress output of instruction numbers, line number notes and addresses in debugging dumps
474 Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
475 Enable CFI tables via GAS assembler directives.
477 fdump-unnumbered-links
478 Common Report Var(flag_dump_unnumbered_links) VarExists
479 Suppress output of previous and next insn numbers in debugging dumps
482 Common Report Var(flag_early_inlining) Init(1) Optimization
483 Perform early inlining
485 feliminate-dwarf2-dups
486 Common Report Var(flag_eliminate_dwarf2_dups)
487 Perform DWARF2 duplicate elimination
489 feliminate-unused-debug-symbols
490 Common Report Var(flag_debug_only_used_symbols)
491 Perform unused type elimination in debug info
493 feliminate-unused-debug-types
494 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
495 Perform unused type elimination in debug info
497 femit-class-debug-always
498 Common Report Var(flag_emit_class_debug_always) Init(0)
499 Do not suppress C++ class debug information.
502 Common Report Var(flag_exceptions) Optimization
503 Enable exception handling
505 fexpensive-optimizations
506 Common Report Var(flag_expensive_optimizations) Optimization
507 Perform a number of minor, expensive optimizations
510 Common Joined RejectNegative
511 -fexcess-precision=[fast|standard] Specify handling of excess floating-point precision
517 Common Report Var(flag_finite_math_only) Optimization
518 Assume no NaNs or infinities are generated
521 Common Joined RejectNegative
522 -ffixed-<register> Mark <register> as being unavailable to the compiler
525 Common Report Var(flag_float_store) Optimization
526 Don't allocate floats and doubles in extended-precision registers
530 Does nothing. Preserved for backward compatibility.
533 Common Report Var(flag_forward_propagate) Optimization
534 Perform a forward propagation pass on RTL
536 ; Nonzero means don't put addresses of constant functions in registers.
537 ; Used for compiling the Unix kernel, where strange substitutions are
538 ; done on the assembly output.
540 Common Report Var(flag_no_function_cse,0)
541 Allow function addresses to be held in registers
544 Common Report Var(flag_function_sections)
545 Place each function into its own section
548 Common Report Var(flag_gcse) Optimization
549 Perform global common subexpression elimination
552 Common Report Var(flag_gcse_lm) Init(1) Optimization
553 Perform enhanced load motion during global common subexpression elimination
556 Common Report Var(flag_gcse_sm) Init(0) Optimization
557 Perform store motion after global common subexpression elimination
560 Common Report Var(flag_gcse_las) Init(0) Optimization
561 Perform redundant load after store elimination in global common subexpression
565 Common Report Var(flag_gcse_after_reload) Optimization
566 Perform global common subexpression elimination after register allocation
569 ; This option is not documented yet as its semantics will change.
571 Common Report Var(flag_graphite)
572 Enable in and out of Graphite representation
575 Common Report Var(flag_loop_strip_mine) Optimization
576 Enable Loop Strip Mining transformation
579 Common Report Var(flag_loop_interchange) Optimization
580 Enable Loop Interchange transformation
583 Common Report Var(flag_loop_block) Optimization
584 Enable Loop Blocking transformation
586 ; This option is not documented as it does not perform any useful optimization.
588 Common Report Var(flag_graphite_identity) Optimization
589 Enable Graphite Identity transformation
591 fguess-branch-probability
592 Common Report Var(flag_guess_branch_prob) Optimization
593 Enable guessing of branch probabilities
595 ; Nonzero means ignore `#ident' directives. 0 means handle them.
596 ; Generate position-independent code for executables if possible
597 ; On SVR4 targets, it also controls whether or not to emit a
598 ; string identifying the compiler.
600 Common Report Var(flag_no_ident,0)
601 Process #ident directives
604 Common Report Var(flag_if_conversion) Optimization
605 Perform conversion of conditional jumps to branchless equivalents
608 Common Report Var(flag_if_conversion2) Optimization
609 Perform conversion of conditional jumps to conditional execution
611 ; -finhibit-size-directive inhibits output of .size for ELF.
612 ; This is used only for compiling crtstuff.c,
613 ; and it may be extended to other effects
614 ; needed for crtstuff.c on other systems.
615 finhibit-size-directive
616 Common Report Var(flag_inhibit_size_directive)
617 Do not generate .size directives
620 Common Report Var(flag_indirect_inlining)
621 Perform indirect inlining
623 ; Nonzero means that functions declared `inline' will be treated
624 ; as `static'. Prevents generation of zillions of copies of unused
625 ; static inline functions; instead, `inlines' are written out
626 ; only when actually used. Used in conjunction with -g. Also
627 ; does the right thing with #pragma interface.
629 Common Report Var(flag_no_inline,0) Init(0)
630 Pay attention to the \"inline\" keyword
632 finline-small-functions
633 Common Report Var(flag_inline_small_functions) Optimization
634 Integrate simple functions into their callers when code size is known to not growth
637 Common Report Var(flag_inline_functions) Optimization
638 Integrate simple functions into their callers
640 finline-functions-called-once
641 Common Report Var(flag_inline_functions_called_once) Init(1) Optimization
642 Integrate functions called once into their callers
645 Common RejectNegative Joined UInteger
648 Common RejectNegative Joined UInteger
649 -finline-limit=<number> Limit the size of inlined functions to <number>
651 finstrument-functions
652 Common Report Var(flag_instrument_function_entry_exit)
653 Instrument function entry and exit with profiling calls
655 finstrument-functions-exclude-function-list=
656 Common RejectNegative Joined
657 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions
659 finstrument-functions-exclude-file-list=
660 Common RejectNegative Joined
661 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files
664 Common Report Var(flag_ipa_cp) Optimization
665 Perform Interprocedural constant propagation
668 Common Report Var(flag_ipa_cp_clone) Optimization
669 Perform cloning to make Interprocedural constant propagation stronger
672 Common Report Var(flag_ipa_pure_const) Init(0) Optimization
673 Discover pure and const functions
676 Common Report Var(flag_ipa_pta) Init(0) Optimization
677 Perform interprocedural points-to analysis
680 Common Report Var(flag_ipa_reference) Init(0) Optimization
681 Discover readonly and non addressable static variables
684 Common Report Var(flag_ipa_type_escape) Init(0) Optimization
685 Type based escape and alias analysis
688 Common Report Var(flag_ipa_matrix_reorg) Optimization
689 Perform matrix layout flattening and transposing based
690 on profiling information.
693 Common Report Var(flag_ipa_struct_reorg)
694 Perform structure layout optimizations based
695 on profiling information.
698 Common Joined RejectNegative
699 -fira-algorithm=[CB|priority] Set the used IRA algorithm
702 Common Joined RejectNegative
703 -fira-region=[one|all|mixed] Set regions for IRA
706 Common Report Var(flag_ira_coalesce) Init(0)
707 Do optimistic coalescing.
709 fira-share-save-slots
710 Common Report Var(flag_ira_share_save_slots) Init(1)
711 Share slots for saving different hard registers.
713 fira-share-spill-slots
714 Common Report Var(flag_ira_share_spill_slots) Init(1)
715 Share stack slots for spilled pseudo-registers.
718 Common RejectNegative Joined UInteger
719 -fira-verbose=<number> Control IRA's level of diagnostic messages.
722 Common Report Var(flag_ivopts) Init(1) Optimization
723 Optimize induction variables on trees
726 Common Var(flag_jump_tables) Init(1) Optimization
727 Use jump tables for sufficiently large switch statements
729 fkeep-inline-functions
730 Common Report Var(flag_keep_inline_functions)
731 Generate code for functions even if they are fully inlined
734 Common Report Var(flag_keep_static_consts) Init(1)
735 Emit static const variables even if they are not used
738 Common Report Var(flag_leading_underscore) Init(-1)
739 Give external symbols a leading underscore
743 Does nothing. Preserved for backward compatibility.
746 Common Report Var(flag_errno_math) Init(1) Optimization
747 Set errno after built-in math functions
750 Common Report Var(mem_report)
751 Report on permanent memory allocation
753 ; This will attempt to merge constant section constants, if 1 only
754 ; string constants and constants from constant pool, if 2 also constant
757 Common Report Var(flag_merge_constants,2) Init(1) Optimization
758 Attempt to merge identical constants and constant variables
761 Common Report Var(flag_merge_constants,1) VarExists Optimization
762 Attempt to merge identical constants across compilation units
765 Common Report Var(flag_merge_debug_strings) Init(1)
766 Attempt to merge identical debug strings across compilation units
769 Common RejectNegative Joined UInteger
770 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping
773 Common Report Var(flag_modulo_sched) Optimization
774 Perform SMS based modulo scheduling before the first scheduling pass
776 fmodulo-sched-allow-regmoves
777 Common Report Var(flag_modulo_sched_allow_regmoves)
778 Perform SMS based modulo scheduling with register moves allowed
780 fmove-loop-invariants
781 Common Report Var(flag_move_loop_invariants) Init(1) Optimization
782 Move loop invariant computations out of loops
785 Common RejectNegative Report Var(flag_mudflap)
786 Add mudflap bounds-checking instrumentation for single-threaded program
789 Common RejectNegative Report VarExists Var(flag_mudflap,2)
790 Add mudflap bounds-checking instrumentation for multi-threaded program
793 Common RejectNegative Report Var(flag_mudflap_ignore_reads)
794 Ignore read operations when inserting mudflap instrumentation
797 Common Var(flag_dce) Init(1) Optimization
798 Use the RTL dead code elimination pass
801 Common Var(flag_dse) Init(1) Optimization
802 Use the RTL dead store elimination pass
804 freschedule-modulo-scheduled-loops
805 Common Report Var(flag_resched_modulo_sched) Optimization
806 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling
809 Common Report Var(flag_non_call_exceptions) Optimization
810 Support synchronous non-call exceptions
813 Common Report Var(flag_omit_frame_pointer) Optimization
814 When possible do not generate stack frames
816 foptimize-register-move
817 Common Report Var(flag_regmove) Optimization
818 Do the full register move optimization pass
820 foptimize-sibling-calls
821 Common Report Var(flag_optimize_sibling_calls) Optimization
822 Optimize sibling and tail recursive calls
825 Common Report Var(pre_ipa_mem_report)
826 Report on memory allocation before interprocedural optimization
829 Common Report Var(post_ipa_mem_report)
830 Report on memory allocation before interprocedural optimization
833 Common Report Var(flag_pack_struct) Optimization
834 Pack structure members together without holes
837 Common RejectNegative Joined UInteger Optimization
838 -fpack-struct=<number> Set initial maximum structure member alignment
841 Common Report Var(flag_pcc_struct_return,1) VarExists
842 Return small aggregates in memory, not registers
845 Common Report Var(flag_peel_loops) Optimization
849 Common Report Var(flag_no_peephole,0) Optimization
850 Enable machine specific peephole optimizations
853 Common Report Var(flag_peephole2) Optimization
854 Enable an RTL peephole pass before sched2
857 Common Report Var(flag_pic,2)
858 Generate position-independent code if possible (large mode)
861 Common Report Var(flag_pie,2)
862 Generate position-independent code for executables if possible (large mode)
865 Common Report Var(flag_pic,1) VarExists
866 Generate position-independent code if possible (small mode)
869 Common Report Var(flag_pie,1) VarExists
870 Generate position-independent code for executables if possible (small mode)
873 Common Joined RejectNegative
874 Specify a plugin to load
877 Common Joined RejectNegative
878 -fplugin-arg-<name>-<key>[=<value>] Specify argument <key>=<value> for plugin <name>
880 fpredictive-commoning
881 Common Report Var(flag_predictive_commoning) Optimization
882 Run predictive commoning optimization.
884 fprefetch-loop-arrays
885 Common Report Var(flag_prefetch_loop_arrays) Optimization
886 Generate prefetch instructions, if available, for arrays in loops
889 Common Report Var(profile_flag)
890 Enable basic program profiling code
893 Common Report Var(profile_arc_flag)
894 Insert arc-based program profiling code
897 Common Joined RejectNegative
898 Set the top-level directory for storing the profile data.
899 The default is 'pwd'.
902 Common Report Var(flag_profile_correction)
903 Enable correction of flow inconsistent profile data input
907 Enable common options for generating profile info for profile feedback directed optimizations
910 Common Joined RejectNegative
911 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=
914 Common Var(flag_profile_use)
915 Enable common options for performing profile feedback directed optimizations
918 Common Joined RejectNegative
919 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=
922 Common Report Var(flag_profile_values)
923 Insert code to profile values of expressions
929 Common Joined RejectNegative
930 -frandom-seed=<string> Make compile reproducible using <string>
932 ; This switch causes the command line that was used to create an
933 ; object file to be recorded into the object file. The exact format
934 ; of this recording is target and binary file format dependent.
935 ; It is related to the -fverbose-asm switch, but that switch only
936 ; records information in the assembler output file as comments, so
937 ; they never reach the object file.
939 Common Report Var(flag_record_gcc_switches)
940 Record gcc command line switches in the object file.
943 Common Report Var(flag_pcc_struct_return,0) VarExists Optimization
944 Return small aggregates in registers
947 Common Report Var(flag_regmove) Optimization
948 Enables a register move optimization
951 Common Report Var(flag_rename_registers) Init(2) Optimization
952 Perform a register renaming optimization pass
955 Common Report Var(flag_reorder_blocks) Optimization
956 Reorder basic blocks to improve code placement
958 freorder-blocks-and-partition
959 Common Report Var(flag_reorder_blocks_and_partition) Optimization
960 Reorder basic blocks and partition into hot and cold sections
963 Common Report Var(flag_reorder_functions) Optimization
964 Reorder functions to improve code placement
966 frerun-cse-after-loop
967 Common Report Var(flag_rerun_cse_after_loop) Init(2) Optimization
968 Add a common subexpression elimination pass after loop optimizations
972 Does nothing. Preserved for backward compatibility.
975 Common Report Var(flag_rounding_math) Optimization
976 Disable optimizations that assume default FP rounding behavior
979 Common Report Var(flag_schedule_interblock) Init(1) Optimization
980 Enable scheduling across basic blocks
983 Common Report Var(flag_schedule_speculative) Init(1) Optimization
984 Allow speculative motion of non-loads
987 Common Report Var(flag_schedule_speculative_load) Optimization
988 Allow speculative motion of some loads
990 fsched-spec-load-dangerous
991 Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
992 Allow speculative motion of more loads
995 Common RejectNegative Joined
996 -fsched-verbose=<number> Set the verbosity level of the scheduler
998 fsched2-use-superblocks
999 Common Report Var(flag_sched2_use_superblocks) Optimization
1000 If scheduling post reload, do superblock scheduling
1003 Common Report Var(flag_sched2_use_traces) Optimization
1004 If scheduling post reload, do trace scheduling
1007 Common Report Var(flag_schedule_insns) Optimization
1008 Reschedule instructions before register allocation
1011 Common Report Var(flag_schedule_insns_after_reload) Optimization
1012 Reschedule instructions after register allocation
1014 ; This flag should be on when a target implements non-trivial
1015 ; scheduling hooks, maybe saving some information for its own sake.
1016 ; On IA64, for example, this is used for correct bundling.
1017 fselective-scheduling
1018 Common Report Var(flag_selective_scheduling) Optimization
1019 Schedule instructions using selective scheduling algorithm
1021 fselective-scheduling2
1022 Common Report Var(flag_selective_scheduling2) Optimization
1023 Run selective scheduling after reload
1025 fsel-sched-pipelining
1026 Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization
1027 Perform software pipelining of inner loops during selective scheduling
1029 fsel-sched-pipelining-outer-loops
1030 Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization
1031 Perform software pipelining of outer loops during selective scheduling
1033 fsel-sched-reschedule-pipelined
1034 Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization
1035 Reschedule pipelined regions without pipelining
1037 ; sched_stalled_insns means that insns can be moved prematurely from the queue
1038 ; of stalled insns into the ready list.
1039 fsched-stalled-insns
1040 Common Report Var(flag_sched_stalled_insns) Optimization UInteger
1041 Allow premature scheduling of queued insns
1043 fsched-stalled-insns=
1044 Common RejectNegative Joined UInteger
1045 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled
1047 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
1048 ; be examined for a dependency on a stalled insn that is candidate for
1049 ; premature removal from the queue of stalled insns into the ready list (has
1050 ; an effect only if the flag 'sched_stalled_insns' is set).
1051 fsched-stalled-insns-dep
1052 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
1053 Set dependence distance checking in premature scheduling of queued insns
1055 fsched-stalled-insns-dep=
1056 Common RejectNegative Joined UInteger
1057 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns
1059 fsched-group-heuristic
1060 Common Report Var(flag_sched_group_heuristic) Init(1) Optimization
1061 Enable the group heuristic in the scheduler
1063 fsched-critical-path-heuristic
1064 Common Report Var(flag_sched_critical_path_heuristic) Init(1) Optimization
1065 Enable the critical path heuristic in the scheduler
1067 fsched-spec-insn-heuristic
1068 Common Report Var(flag_sched_spec_insn_heuristic) Init(1) Optimization
1069 Enable the speculative instruction heuristic in the scheduler
1071 fsched-reg-pressure-heuristic
1072 Common Report Var(flag_sched_reg_pressure_heuristic) Init(1) Optimization
1073 Enable the register pressure heuristic in the scheduler
1075 fsched-rank-heuristic
1076 Common Report Var(flag_sched_rank_heuristic) Init(1) Optimization
1077 Enable the rank heuristic in the scheduler
1079 fsched-last-insn-heuristic
1080 Common Report Var(flag_sched_last_insn_heuristic) Init(1) Optimization
1081 Enable the last instruction heuristic in the scheduler
1083 fsched-dep-count-heuristic
1084 Common Report Var(flag_sched_dep_count_heuristic) Init(1) Optimization
1085 Enable the dependent count heuristic in the scheduler
1088 Common Report Var(flag_section_anchors) Optimization
1089 Access data in the same section from shared anchor points
1093 Does nothing. Preserved for backward compatibility.
1096 Common C ObjC C++ ObjC++ Report Var(flag_show_column) Init(1)
1097 Show column numbers in diagnostics, when available. Default on
1100 Common Report Var(flag_signaling_nans) Optimization
1101 Disable optimizations observable by IEEE signaling NaNs
1104 Common Report Var(flag_signed_zeros) Init(1) Optimization
1105 Disable floating point optimizations that ignore the IEEE signedness of zero
1107 fsingle-precision-constant
1108 Common Report Var(flag_single_precision_constant) Optimization
1109 Convert floating point constants to single precision constants
1111 fsplit-ivs-in-unroller
1112 Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
1113 Split lifetimes of induction variables when loops are unrolled
1116 Common Report Var(flag_split_wide_types) Optimization
1117 Split wide types into independent registers
1119 fvariable-expansion-in-unroller
1120 Common Report Var(flag_variable_expansion_in_unroller) Optimization
1121 Apply variable expansion when loops are unrolled
1124 Common Report RejectNegative Joined
1125 -fstack-check=[no|generic|specific] Insert stack checking code into the program
1129 Insert stack checking code into the program. Same as -fstack-check=specific
1134 fstack-limit-register=
1135 Common RejectNegative Joined
1136 -fstack-limit-register=<register> Trap if the stack goes past <register>
1138 fstack-limit-symbol=
1139 Common RejectNegative Joined
1140 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>
1143 Common Report Var(flag_stack_protect, 1)
1144 Use propolice as a stack protection method
1146 fstack-protector-all
1147 Common Report RejectNegative Var(flag_stack_protect, 2) VarExists
1148 Use a stack protection method for every function
1152 Does nothing. Preserved for backward compatibility.
1154 ; Nonzero if we should do (language-dependent) alias analysis.
1155 ; Typically, this analysis will assume that expressions of certain
1156 ; types do not alias expressions of certain other types. Only used
1157 ; if alias analysis (in general) is enabled.
1159 Common Report Var(flag_strict_aliasing) Optimization
1160 Assume strict aliasing rules apply
1163 Common Report Var(flag_strict_overflow)
1164 Treat signed overflow as undefined
1167 Common Report Var(flag_syntax_only)
1168 Check for syntax errors, then stop
1171 Common Report Var(flag_test_coverage)
1172 Create data files needed by \"gcov\"
1175 Common Report Var(flag_thread_jumps) Optimization
1176 Perform jump threading optimizations
1179 Common Report Var(time_report)
1180 Report the time taken by each compiler pass
1183 Common Joined RejectNegative
1184 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model
1187 Common Report Var(flag_toplevel_reorder) Init(2) Optimization
1188 Reorder top level functions, variables, and asms
1191 Common Report Var(flag_tracer)
1192 Perform superblock formation via tail duplication
1194 ; Zero means that floating-point math operations cannot generate a
1195 ; (user-visible) trap. This is the case, for example, in nonstop
1196 ; IEEE 754 arithmetic.
1198 Common Report Var(flag_trapping_math) Init(1) Optimization
1199 Assume floating-point operations can trap
1202 Common Report Var(flag_trapv) Optimization
1203 Trap for signed overflow in addition, subtraction and multiplication
1206 Common Report Var(flag_tree_ccp) Optimization
1207 Enable SSA-CCP optimization on trees
1211 Does nothing. Preserved for backward compatibility.
1214 Common Report Var(flag_tree_ch) Optimization
1215 Enable loop header copying on trees
1218 Common Report Var(flag_tree_copyrename) Optimization
1219 Replace SSA temporaries with better names in copies
1222 Common Report Var(flag_tree_copy_prop) Optimization
1223 Enable copy propagation on trees
1225 ftree-store-copy-prop
1227 Does nothing. Preserved for backward compatibility.
1230 Common Report Var(flag_tree_cselim) Init(2) Optimization
1231 Transform condition stores into unconditional ones
1233 ftree-switch-conversion
1234 Common Report Var(flag_tree_switch_conversion) Optimization
1235 Perform conversions of switch initializations.
1238 Common Report Var(flag_tree_dce) Optimization
1239 Enable SSA dead code elimination optimization on trees
1241 ftree-dominator-opts
1242 Common Report Var(flag_tree_dom) Optimization
1243 Enable dominator optimizations
1246 Common Report Var(flag_tree_dse) Optimization
1247 Enable dead store elimination
1250 Common Report Var(flag_tree_forwprop) Init(1) Optimization
1251 Enable forward propagation on trees
1254 Common Report Var(flag_tree_fre) Optimization
1255 Enable Full Redundancy Elimination (FRE) on trees
1257 ftree-loop-distribution
1258 Common Report Var(flag_tree_loop_distribution) Optimization
1259 Enable loop distribution on trees
1262 Common Report Var(flag_tree_loop_im) Init(1) Optimization
1263 Enable loop invariant motion on trees
1266 Common Report Var(flag_tree_loop_linear) Optimization
1267 Enable linear loop transforms on trees
1270 Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
1271 Create canonical induction variables in loops
1274 Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
1275 Enable loop optimizations on tree level
1277 ftree-parallelize-loops=
1278 Common Report Joined UInteger Var(flag_tree_parallelize_loops) Init(1)
1279 Enable automatic parallelization of loops
1282 Common Report Var(flag_tree_phiprop) Init(1) Optimization
1283 Enable hoisting loads from conditional pointers.
1286 Common Report Var(flag_tree_pre) Optimization
1287 Enable SSA-PRE optimization on trees
1290 Common Report Var(flag_tree_pta) Init(1) Optimization
1291 Perform function-local points-to analysis on trees.
1294 Common Report Var(flag_tree_reassoc) Init(1) Optimization
1295 Enable reassociation on tree level
1299 Does nothing. Preserved for backward compatibility.
1302 Common Report Var(flag_tree_sink) Optimization
1303 Enable SSA code sinking on trees
1306 Common Report Var(flag_tree_sra) Optimization
1307 Perform scalar replacement of aggregates
1310 Common Report Var(flag_tree_ter) Init(1) Optimization
1311 Replace temporary expressions in the SSA->normal pass
1314 Common Report Var(flag_tree_live_range_split) Optimization
1315 Perform live range splitting during the SSA->normal pass
1318 Common Report Var(flag_tree_vrp) Init(0) Optimization
1319 Perform Value Range Propagation on trees
1322 Common Report Var(flag_unit_at_a_time) Init(1) Optimization
1323 Compile whole compilation unit at a time
1326 Common Report Var(flag_unroll_loops) Optimization
1327 Perform loop unrolling when iteration count is known
1330 Common Report Var(flag_unroll_all_loops) Optimization
1331 Perform loop unrolling for all loops
1333 ; Nonzero means that loop optimizer may assume that the induction variables
1334 ; that control loops do not overflow and that the loops with nontrivial
1335 ; exit condition are not infinite
1336 funsafe-loop-optimizations
1337 Common Report Var(flag_unsafe_loop_optimizations) Optimization
1338 Allow loop optimizations to assume that the loops behave in normal way
1341 Common Report Var(flag_associative_math)
1342 Allow optimization for floating-point arithmetic which may change the
1343 result of the operation due to rounding.
1346 Common Report Var(flag_reciprocal_math)
1347 Same as -fassociative-math for expressions which include division.
1349 ; Nonzero means that unsafe floating-point math optimizations are allowed
1350 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
1351 ; are allowed to assume that their arguments and results are "normal"
1352 ; (e.g., nonnegative for SQRT).
1353 funsafe-math-optimizations
1354 Common Report Var(flag_unsafe_math_optimizations) Optimization
1355 Allow math optimizations that may violate IEEE or ISO standards
1358 Common Report Var(flag_unswitch_loops) Optimization
1359 Perform loop unswitching
1362 Common Report Var(flag_unwind_tables) Optimization
1363 Just generate unwind tables for exception handling
1366 Common Report Var(flag_var_tracking) VarExists Optimization
1367 Perform variable tracking
1369 fvar-tracking-uninit
1370 Common Report Var(flag_var_tracking_uninit) Optimization
1371 Perform variable tracking and also tag variables that are uninitialized
1374 Common Report Var(flag_tree_vectorize) Optimization
1375 Enable loop vectorization on trees
1378 Common Report Var(flag_tree_slp_vectorize) Init(2) Optimization
1379 Enable basic block vectorization (SLP) on trees
1382 Common Report Var(flag_vect_cost_model) Optimization
1383 Enable use of cost model in vectorization
1385 ftree-vect-loop-version
1386 Common Report Var(flag_tree_vect_loop_version) Init(1) Optimization
1387 Enable loop versioning when doing loop vectorization on trees
1389 ftree-vectorizer-verbose=
1390 Common RejectNegative Joined
1391 -ftree-vectorizer-verbose=<number> Set the verbosity level of the vectorizer
1394 Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
1395 Enable copy propagation of scalar-evolution information.
1397 ; -fverbose-asm causes extra commentary information to be produced in
1398 ; the generated assembly code (to make it more readable). This option
1399 ; is generally only of use to those who actually need to read the
1400 ; generated assembly code (perhaps while debugging the compiler itself).
1401 ; -fno-verbose-asm, the default, causes the extra information
1402 ; to not be added and is useful when comparing two assembler files.
1404 Common Report Var(flag_verbose_asm)
1405 Add extra commentary to assembler output
1408 Common Joined RejectNegative
1409 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility
1413 Common Report Var(flag_value_profile_transformations) Optimization
1414 Use expression value profiles in optimizations
1417 Common Report Var(flag_web) Init(2) Optimization
1418 Construct webs and split unrelated uses of single variable
1420 ftree-builtin-call-dce
1421 Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization
1422 Enable conditional dead code elimination for builtin calls
1425 Common Report Var(flag_whole_program) Init(0) Optimization
1426 Perform whole program optimizations
1429 Common Report Var(flag_wrapv) Optimization
1430 Assume signed arithmetic overflow wraps around
1432 fzero-initialized-in-bss
1433 Common Report Var(flag_zero_initialized_in_bss) Init(1)
1434 Put zero initialized data in the bss section
1437 Common JoinedOrMissing
1438 Generate debug information in default format
1441 Common JoinedOrMissing Negative(gdwarf-)
1442 Generate debug information in COFF format
1445 Common Joined UInteger Var(dwarf_version) Init(2) Negative(gstabs)
1446 Generate debug information in DWARF v2 (or later) format
1449 Common JoinedOrMissing
1450 Generate debug information in default extended format
1453 Common JoinedOrMissing Negative(gstabs+)
1454 Generate debug information in STABS format
1457 Common JoinedOrMissing Negative(gvms)
1458 Generate debug information in extended STABS format
1461 Common Report Var(flag_gtoggle)
1462 Toggle debug information generation
1465 Common JoinedOrMissing Negative(gxcoff)
1466 Generate debug information in VMS format
1469 Common JoinedOrMissing Negative(gxcoff+)
1470 Generate debug information in XCOFF format
1473 Common JoinedOrMissing Negative(gcoff)
1474 Generate debug information in extended XCOFF format
1477 Common Joined Separate
1478 -o <file> Place output into <file>
1481 Common Var(profile_flag)
1482 Enable function profiling
1485 Common Var(pedantic)
1486 Issue warnings needed for strict compliance to the standard
1490 Like -pedantic but issue them as errors
1493 Common Var(quiet_flag)
1494 Do not display functions compiled or elapsed time
1497 Common Var(version_flag)
1498 Display the compiler's version
1501 Common Var(inhibit_warnings)
1505 Common RejectNegative Negative(pie)
1506 Create a shared library
1509 Common RejectNegative Negative(shared)
1510 Create a position independent executable
1512 ; This comment is to ensure we retain the blank line above.