1 ; Options for the language- and target-independent parts of the compiler.
3 ; Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008
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 three 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).
52 --param <param>=<value> Set parameter <param> to value. See below for a complete list of parameters
58 Common Joined Separate UInteger
59 -G<number> Put global and static data smaller than <number> bytes into a special section (on some targets)
62 Common JoinedOrMissing Optimization
63 -O<number> Set optimization level to <number>
67 Optimize for space rather than speed
71 This switch is deprecated; use -Wextra instead
74 Common Var(warn_aggregate_return) Warning
75 Warn about returning structures, unions or arrays
78 Common Var(warn_array_bounds) Warning
79 Warn if an array is accessed out of bounds
82 Common Var(warn_attributes) Init(1) Warning
83 Warn about inappropriate attribute usage
86 Common Var(warn_cast_align) Warning
87 Warn about pointer casts which increase alignment
89 Wdeprecated-declarations
90 Common Var(warn_deprecated_decl) Init(1) Warning
91 Warn about uses of __attribute__((deprecated)) declarations
93 Wdisabled-optimization
94 Common Var(warn_disabled_optimization) Warning
95 Warn when an optimization pass is disabled
97 Wdisallowed-function-list=
98 Common RejectNegative Joined Warning
99 Warn on calls to these functions
102 Common Var(warnings_are_errors)
103 Treat all warnings as errors
107 Treat specified warning as error
111 Print extra (possibly unwanted) warnings
114 Common Var(flag_fatal_errors)
115 Exit on the first error occurred
118 Common RejectNegative Joined UInteger
119 -Wframe-larger-than=<number> Warn if a function's stack frame requires more than <number> bytes
122 Common Var(warn_inline) Warning
123 Warn when an inlined function cannot be inlined
126 Common RejectNegative Joined UInteger Warning
129 Common RejectNegative Joined UInteger Warning
130 -Wlarger-than=<number> Warn if an object is larger than <number> bytes
133 Common Warning Var(warn_logical_op)
134 Warn when a logical operator is suspicously always evaluating to true or false
136 Wunsafe-loop-optimizations
137 Common Var(warn_unsafe_loop_optimizations) Warning
138 Warn if the loop cannot be optimized due to nontrivial assumptions.
141 Common Var(warn_missing_noreturn) Warning
142 Warn about functions which might be candidates for __attribute__((noreturn))
145 Common Var(warn_mudflap) Init(1) Warning
146 Warn about constructs not instrumented by -fmudflap
149 Common Var(warn_overflow) Init(1) Warning
150 Warn about overflow in arithmetic expressions
153 Common Var(warn_packed) Warning
154 Warn when the packed attribute has no effect on struct layout
157 Common Var(warn_padded) Warning
158 Warn when padding is required to align structure members
161 Common Var(warn_shadow) Warning
162 Warn when one local variable shadows another
165 Common Var(warn_stack_protect) Warning
166 Warn when not issuing stack smashing protection for some reason
170 Warn about code which might break strict aliasing rules
173 Common Joined UInteger Var(warn_strict_aliasing) Init(-1) Warning
174 Warn about code which might break strict aliasing rules
178 Warn about optimizations that assume that signed overflow is undefined
181 Common Joined UInteger Var(warn_strict_overflow) Init(-1) Warning
182 Warn about optimizations that assume that signed overflow is undefined
185 Common Var(warn_switch) Warning
186 Warn about enumerated switches, with no default, missing a case
189 Common Var(warn_switch_default) Warning
190 Warn about enumerated switches missing a \"default:\" statement
193 Common Var(warn_switch_enum) Warning
194 Warn about all enumerated switches missing a specific case
197 Common Var(warn_system_headers) Warning
198 Do not suppress warnings from system headers
201 Common Var(warn_type_limits) Init(-1) Warning
202 Warn if a comparison is always true or always false due to the limited range of the data type
205 Common Var(warn_uninitialized) Warning
206 Warn about uninitialized automatic variables
209 Common Var(warn_notreached) Warning
210 Warn about code that will never be executed
213 Common Var(warn_unused) Init(0) Warning
214 Enable all -Wunused- warnings
217 Common Var(warn_unused_function) Init(-1) Warning
218 Warn when a function is unused
221 Common Var(warn_unused_label) Init(-1) Warning
222 Warn when a label is unused
225 Common Var(warn_unused_parameter) Init(-1) Warning
226 Warn when a function parameter is unused
229 Common Var(warn_unused_value) Init(-1) Warning
230 Warn when an expression value is unused
233 Common Var(warn_unused_variable) Init(-1) Warning
234 Warn when a variable is unused
237 Common RejectNegative Var(warn_coverage_mismatch) Warning
238 Warn instead of error in case profiles in -fprofile-use do not match
242 -aux-info <file> Emit declaration information into <file>
255 -d<letters> Enable dumps from specific passes of the compiler
259 -dumpbase <file> Set the file basename to be used for dumps
261 ; The version of the C++ ABI in use. The following values are allowed:
263 ; 0: The version of the ABI believed most conformant with the C++ ABI
264 ; specification. This ABI may change as bugs are discovered and fixed.
265 ; Therefore, 0 will not necessarily indicate the same ABI in different
268 ; 1: The version of the ABI first used in G++ 3.2.
270 ; 2: The version of the ABI first used in G++ 3.4.
272 ; Additional positive integers will be assigned as new versions of
273 ; the ABI become the default version of the ABI.
275 Common Joined UInteger Var(flag_abi_version) Init(2)
278 Common Report Var(align_functions,0) Optimization UInteger
279 Align the start of functions
282 Common RejectNegative Joined UInteger
285 Common Report Var(align_jumps,0) Optimization UInteger
286 Align labels which are only reached by jumping
289 Common RejectNegative Joined UInteger
292 Common Report Var(align_labels,0) Optimization UInteger
296 Common RejectNegative Joined UInteger
299 Common Report Var(align_loops) Optimization UInteger
300 Align the start of loops
303 Common RejectNegative Joined UInteger
305 ; This flag is only tested if alias checking is enabled.
306 ; 0 if pointer arguments may alias each other. True in C.
307 ; 1 if pointer arguments may not alias each other but may alias
309 ; 2 if pointer arguments may not alias each other and may not
310 ; alias global variables.
311 ; 3 if pointer arguments may not alias anything. True in Fortran.
312 ; Set by the front end.
314 Common Report Var(flag_argument_noalias,0) Optimization
315 Specify that arguments may alias each other and globals
318 Common Report Var(flag_argument_noalias,1) VarExists Optimization
319 Assume arguments may alias globals but not each other
321 fargument-noalias-global
322 Common Report Var(flag_argument_noalias,2) VarExists Optimization
323 Assume arguments alias neither each other nor globals
325 fargument-noalias-anything
326 Common Report Var(flag_argument_noalias,3) VarExists Optimization
327 Assume arguments alias no other storage
329 fasynchronous-unwind-tables
330 Common Report Var(flag_asynchronous_unwind_tables) Optimization
331 Generate unwind tables that are exact at each instruction boundary
334 Common Report Var(flag_auto_inc_dec) Init(1)
335 Generate auto-inc/dec instructions
337 ; -fcheck-bounds causes gcc to generate array bounds checks.
338 ; For C, C++ and ObjC: defaults off.
339 ; For Java: defaults to on.
340 ; For Fortran: defaults to off.
342 Common Report Var(flag_bounds_check)
343 Generate code to check bounds before indexing arrays
346 Common Report Var(flag_branch_on_count_reg) Init(1) Optimization
347 Replace add, compare, branch with branch on count register
349 fbranch-probabilities
350 Common Report Var(flag_branch_probabilities) Optimization
351 Use profiling information for branch probabilities
353 fbranch-target-load-optimize
354 Common Report Var(flag_branch_target_load_optimize) Optimization
355 Perform branch target load optimization before prologue / epilogue threading
357 fbranch-target-load-optimize2
358 Common Report Var(flag_branch_target_load_optimize2) Optimization
359 Perform branch target load optimization after prologue / epilogue threading
362 Common Report Var(flag_btr_bb_exclusive) Optimization
363 Restrict target load migration not to re-use registers in any basic block
366 Common Joined RejectNegative
367 -fcall-saved-<register> Mark <register> as being preserved across functions
370 Common Joined RejectNegative
371 -fcall-used-<register> Mark <register> as being corrupted by function calls
373 ; Nonzero for -fcaller-saves: allocate values in regs that need to
374 ; be saved across function calls, if that produces overall better code.
375 ; Optional now, so people can test it.
377 Common Report Var(flag_caller_saves) Optimization
378 Save registers around function calls
381 Common Report Var(flag_check_data_deps)
382 Compare the results of several data dependence analyzers.
385 Common Report Var(flag_no_common,0) Optimization
386 Do not put uninitialized globals in the common section
389 Common Report Var(flag_cprop_registers) Optimization
390 Perform a register copy-propagation optimization pass
393 Common Report Var(flag_crossjumping) Optimization
394 Perform cross-jumping optimization
397 Common Report Var(flag_cse_follow_jumps) Optimization
398 When running CSE, follow jumps to their targets
401 Common Report Var(flag_cse_skip_blocks) Optimization
402 When running CSE, follow conditional jumps
405 Common Report Var(flag_cx_limited_range) Optimization
406 Omit range reduction step when performing complex division
409 Common Report Var(flag_cx_fortran_rules) Optimization
410 Complex multiplication and division follow Fortran rules
413 Common Report Var(flag_data_sections) Optimization
414 Place data items into their own section
418 List all available debugging counters with their limits and counts.
421 Common RejectNegative Joined
422 -fdbg-cnt=<counter>:<limit>[,<counter>:<limit>,...] Set the debug counter limit.
425 Common Joined RejectNegative
426 Map one directory name to another in debug information
428 ; Nonzero for -fdefer-pop: don't pop args after each function call
429 ; instead save them up to pop many calls' args with one insns.
431 Common Report Var(flag_defer_pop) Optimization
432 Defer popping functions args from stack until later
435 Common Report Var(flag_delayed_branch) Optimization
436 Attempt to fill delay slots of branch instructions
438 fdelete-null-pointer-checks
439 Common Report Var(flag_delete_null_pointer_checks) Optimization
440 Delete useless null pointer checks
442 fdiagnostics-show-location=
443 Common Joined RejectNegative
444 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics
446 fdiagnostics-show-option
448 Amend appropriate diagnostic messages with the command line option that controls them
451 Common Joined RejectNegative
452 -fdump-<type> Dump various compiler internals to a file
455 Common Report Var(flag_dump_noaddr)
456 Suppress output of addresses in debugging dumps
459 Common Report Var(flag_dump_unnumbered) VarExists
460 Suppress output of instruction numbers, line number notes and addresses in debugging dumps
463 Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE)
464 Enable CFI tables via GAS assembler directives.
467 Common Report Var(flag_early_inlining) Init(1) Optimization
468 Perform early inlining
470 feliminate-dwarf2-dups
471 Common Report Var(flag_eliminate_dwarf2_dups)
472 Perform DWARF2 duplicate elimination
474 feliminate-unused-debug-symbols
475 Common Report Var(flag_debug_only_used_symbols)
476 Perform unused type elimination in debug info
478 feliminate-unused-debug-types
479 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
480 Perform unused type elimination in debug info
482 femit-class-debug-always
483 Common Report Var(flag_emit_class_debug_always) Init(0)
484 Do not suppress C++ class debug information.
487 Common Report Var(flag_exceptions) Optimization
488 Enable exception handling
490 fexpensive-optimizations
491 Common Report Var(flag_expensive_optimizations) Optimization
492 Perform a number of minor, expensive optimizations
498 Common Report Var(flag_finite_math_only) Optimization
499 Assume no NaNs or infinities are generated
502 Common Joined RejectNegative
503 -ffixed-<register> Mark <register> as being unavailable to the compiler
506 Common Report Var(flag_float_store) Optimization
507 Don't allocate floats and doubles in extended-precision registers
511 Does nothing. Preserved for backward compatibility.
514 Common Report Var(flag_forward_propagate) Optimization
515 Perform a forward propagation pass on RTL
517 ; Nonzero means don't put addresses of constant functions in registers.
518 ; Used for compiling the Unix kernel, where strange substitutions are
519 ; done on the assembly output.
521 Common Report Var(flag_no_function_cse,0)
522 Allow function addresses to be held in registers
525 Common Report Var(flag_function_sections)
526 Place each function into its own section
529 Common Report Var(flag_gcse) Optimization
530 Perform global common subexpression elimination
533 Common Report Var(flag_gcse_lm) Init(1) Optimization
534 Perform enhanced load motion during global common subexpression elimination
537 Common Report Var(flag_gcse_sm) Init(0) Optimization
538 Perform store motion after global common subexpression elimination
541 Common Report Var(flag_gcse_las) Init(0) Optimization
542 Perform redundant load after store elimination in global common subexpression
546 Common Report Var(flag_gcse_after_reload) Optimization
547 Perform global common subexpression elimination after register allocation
550 fguess-branch-probability
551 Common Report Var(flag_guess_branch_prob) Optimization
552 Enable guessing of branch probabilities
554 ; Nonzero means ignore `#ident' directives. 0 means handle them.
555 ; Generate position-independent code for executables if possible
556 ; On SVR4 targets, it also controls whether or not to emit a
557 ; string identifying the compiler.
559 Common Report Var(flag_no_ident,0)
560 Process #ident directives
563 Common Report Var(flag_if_conversion) Optimization
564 Perform conversion of conditional jumps to branchless equivalents
567 Common Report Var(flag_if_conversion2) Optimization
568 Perform conversion of conditional jumps to conditional execution
570 ; -finhibit-size-directive inhibits output of .size for ELF.
571 ; This is used only for compiling crtstuff.c,
572 ; and it may be extended to other effects
573 ; needed for crtstuff.c on other systems.
574 finhibit-size-directive
575 Common Report Var(flag_inhibit_size_directive)
576 Do not generate .size directives
579 Common Report Var(flag_indirect_inlining)
580 Perform indirect inlining
582 ; Nonzero means that functions declared `inline' will be treated
583 ; as `static'. Prevents generation of zillions of copies of unused
584 ; static inline functions; instead, `inlines' are written out
585 ; only when actually used. Used in conjunction with -g. Also
586 ; does the right thing with #pragma interface.
588 Common Report Var(flag_no_inline,0) Init(0)
589 Pay attention to the \"inline\" keyword
591 finline-small-functions
592 Common Report Var(flag_inline_small_functions) Optimization
593 Integrate simple functions into their callers when code size is known to not growth
596 Common Report Var(flag_inline_functions) Optimization
597 Integrate simple functions into their callers
599 finline-functions-called-once
600 Common Report Var(flag_inline_functions_called_once) Init(1) Optimization
601 Integrate functions called once into their callers
604 Common RejectNegative Joined UInteger
607 Common RejectNegative Joined UInteger
608 -finline-limit=<number> Limit the size of inlined functions to <number>
610 finstrument-functions
611 Common Report Var(flag_instrument_function_entry_exit)
612 Instrument function entry and exit with profiling calls
614 finstrument-functions-exclude-function-list=
615 Common RejectNegative Joined
616 -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions
618 finstrument-functions-exclude-file-list=
619 Common RejectNegative Joined
620 -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files
623 Common Report Var(flag_ipa_cp) Optimization
624 Perform Interprocedural constant propagation
627 Common Report Var(flag_ipa_cp_clone) Optimization
628 Perform cloning to make Interprocedural constant propagation stronger
631 Common Report Var(flag_ipa_pure_const) Init(0) Optimization
632 Discover pure and const functions
635 Common Report Var(flag_ipa_pta) Init(0) Optimization
636 Perform interprocedural points-to analysis
639 Common Report Var(flag_ipa_reference) Init(0) Optimization
640 Discover readonly and non addressable static variables
643 Common Report Var(flag_ipa_type_escape) Init(0) Optimization
644 Type based escape and alias analysis
647 Common Report Var(flag_ipa_matrix_reorg) Optimization
648 Perform matrix layout flattening and transposing based
649 on profiling information.
652 Common Report Var(flag_ipa_struct_reorg)
653 Perform structure layout optimizations based
654 on profiling information.
657 Common Report Var(flag_ivopts) Init(1) Optimization
658 Optimize induction variables on trees
661 Common Var(flag_jump_tables) Init(1) Optimization
662 Use jump tables for sufficiently large switch statements
664 fkeep-inline-functions
665 Common Report Var(flag_keep_inline_functions)
666 Generate code for functions even if they are fully inlined
669 Common Report Var(flag_keep_static_consts) Init(1)
670 Emit static const variables even if they are not used
673 Common Report Var(flag_leading_underscore) Init(-1)
674 Give external symbols a leading underscore
678 Does nothing. Preserved for backward compatibility.
681 Common Report Var(flag_errno_math) Init(1) Optimization
682 Set errno after built-in math functions
685 Common Report Var(mem_report)
686 Report on permanent memory allocation
688 ; This will attempt to merge constant section constants, if 1 only
689 ; string constants and constants from constant pool, if 2 also constant
692 Common Report Var(flag_merge_constants,2) Init(1) Optimization
693 Attempt to merge identical constants and constant variables
696 Common Report Var(flag_merge_constants,1) VarExists Optimization
697 Attempt to merge identical constants across compilation units
700 Common Report Var(flag_merge_debug_strings) Init(1)
701 Attempt to merge identical debug strings across compilation units
704 Common RejectNegative Joined UInteger
705 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping
708 Common Report Var(flag_modulo_sched) Optimization
709 Perform SMS based modulo scheduling before the first scheduling pass
711 fmodulo-sched-allow-regmoves
712 Common Report Var(flag_modulo_sched_allow_regmoves)
713 Perform SMS based modulo scheduling with register moves allowed
715 fmove-loop-invariants
716 Common Report Var(flag_move_loop_invariants) Init(1) Optimization
717 Move loop invariant computations out of loops
720 Common RejectNegative Report Var(flag_mudflap)
721 Add mudflap bounds-checking instrumentation for single-threaded program
724 Common RejectNegative Report VarExists Var(flag_mudflap,2)
725 Add mudflap bounds-checking instrumentation for multi-threaded program
728 Common RejectNegative Report Var(flag_mudflap_ignore_reads)
729 Ignore read operations when inserting mudflap instrumentation
732 Common Var(flag_dce) Init(1) Optimization
733 Use the RTL dead code elimination pass
736 Common Var(flag_dse) Init(1) Optimization
737 Use the RTL dead store elimination pass
739 freschedule-modulo-scheduled-loops
740 Common Report Var(flag_resched_modulo_sched) Optimization
741 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling
744 Common Report Var(flag_non_call_exceptions) Optimization
745 Support synchronous non-call exceptions
748 Common Report Var(flag_omit_frame_pointer) Optimization
749 When possible do not generate stack frames
751 foptimize-register-move
752 Common Report Var(flag_regmove) Optimization
753 Do the full register move optimization pass
755 foptimize-sibling-calls
756 Common Report Var(flag_optimize_sibling_calls) Optimization
757 Optimize sibling and tail recursive calls
760 Common Report Var(pre_ipa_mem_report)
761 Report on memory allocation before interprocedural optimization
764 Common Report Var(post_ipa_mem_report)
765 Report on memory allocation before interprocedural optimization
768 Common Report Var(flag_pack_struct) Optimization
769 Pack structure members together without holes
772 Common RejectNegative Joined UInteger Optimization
773 -fpack-struct=<number> Set initial maximum structure member alignment
776 Common Report Var(flag_pcc_struct_return,1) VarExists
777 Return small aggregates in memory, not registers
780 Common Report Var(flag_peel_loops) Optimization
784 Common Report Var(flag_no_peephole,0) Optimization
785 Enable machine specific peephole optimizations
788 Common Report Var(flag_peephole2) Optimization
789 Enable an RTL peephole pass before sched2
792 Common Report Var(flag_pic,2)
793 Generate position-independent code if possible (large mode)
796 Common Report Var(flag_pie,2)
797 Generate position-independent code for executables if possible (large mode)
800 Common Report Var(flag_pic,1) VarExists
801 Generate position-independent code if possible (small mode)
804 Common Report Var(flag_pie,1) VarExists
805 Generate position-independent code for executables if possible (small mode)
807 fpredictive-commoning
808 Common Report Var(flag_predictive_commoning) Optimization
809 Run predictive commoning optimization.
811 fprefetch-loop-arrays
812 Common Report Var(flag_prefetch_loop_arrays) Optimization
813 Generate prefetch instructions, if available, for arrays in loops
816 Common Report Var(profile_flag)
817 Enable basic program profiling code
820 Common Report Var(profile_arc_flag)
821 Insert arc-based program profiling code
824 Common Joined RejectNegative
825 Set the top-level directory for storing the profile data.
826 The default is 'pwd'.
829 Common Report Var(flag_profile_correction)
830 Enable correction of flow inconsistent profile data input
834 Enable common options for generating profile info for profile feedback directed optimizations
837 Common Joined RejectNegative
838 Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir=
841 Common Var(flag_profile_use)
842 Enable common options for performing profile feedback directed optimizations
845 Common Joined RejectNegative
846 Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir=
849 Common Report Var(flag_profile_values)
850 Insert code to profile values of expressions
856 Common Joined RejectNegative
857 -frandom-seed=<string> Make compile reproducible using <string>
859 ; This switch causes the command line that was used to create an
860 ; object file to be recorded into the object file. The exact format
861 ; of this recording is target and binary file format dependent.
862 ; It is related to the -fverbose-asm switch, but that switch only
863 ; records information in the assembler output file as comments, so
864 ; they never reach the object file.
866 Common Report Var(flag_record_gcc_switches)
867 Record gcc command line switches in the object file.
870 Common Report Var(flag_pcc_struct_return,0) VarExists Optimization
871 Return small aggregates in registers
874 Common Report Var(flag_regmove) Optimization
875 Enables a register move optimization
878 Common Report Var(flag_rename_registers) Init(2) Optimization
879 Perform a register renaming optimization pass
882 Common Report Var(flag_reorder_blocks) Optimization
883 Reorder basic blocks to improve code placement
885 freorder-blocks-and-partition
886 Common Report Var(flag_reorder_blocks_and_partition) Optimization
887 Reorder basic blocks and partition into hot and cold sections
890 Common Report Var(flag_reorder_functions) Optimization
891 Reorder functions to improve code placement
893 frerun-cse-after-loop
894 Common Report Var(flag_rerun_cse_after_loop) Init(2) Optimization
895 Add a common subexpression elimination pass after loop optimizations
899 Does nothing. Preserved for backward compatibility.
902 Common Report Var(flag_rounding_math) Optimization
903 Disable optimizations that assume default FP rounding behavior
906 Common Report Var(flag_schedule_interblock) Init(1) Optimization
907 Enable scheduling across basic blocks
910 Common Report Var(flag_schedule_speculative) Init(1) Optimization
911 Allow speculative motion of non-loads
914 Common Report Var(flag_schedule_speculative_load) Optimization
915 Allow speculative motion of some loads
917 fsched-spec-load-dangerous
918 Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
919 Allow speculative motion of more loads
922 Common RejectNegative Joined
923 -fsched-verbose=<number> Set the verbosity level of the scheduler
925 fsched2-use-superblocks
926 Common Report Var(flag_sched2_use_superblocks) Optimization
927 If scheduling post reload, do superblock scheduling
930 Common Report Var(flag_sched2_use_traces) Optimization
931 If scheduling post reload, do trace scheduling
934 Common Report Var(flag_schedule_insns) Optimization
935 Reschedule instructions before register allocation
938 Common Report Var(flag_schedule_insns_after_reload) Optimization
939 Reschedule instructions after register allocation
941 ; sched_stalled_insns means that insns can be moved prematurely from the queue
942 ; of stalled insns into the ready list.
944 Common Report Var(flag_sched_stalled_insns) Optimization UInteger
945 Allow premature scheduling of queued insns
947 fsched-stalled-insns=
948 Common RejectNegative Joined UInteger
949 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled
951 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
952 ; be examined for a dependency on a stalled insn that is candidate for
953 ; premature removal from the queue of stalled insns into the ready list (has
954 ; an effect only if the flag 'sched_stalled_insns' is set).
955 fsched-stalled-insns-dep
956 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger
957 Set dependence distance checking in premature scheduling of queued insns
959 fsched-stalled-insns-dep=
960 Common RejectNegative Joined UInteger
961 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns
964 Common Report Var(flag_section_anchors) Optimization
965 Access data in the same section from shared anchor points
967 frtl-abstract-sequences
968 Common Report Var(flag_rtl_seqabstr) Optimization
969 Perform sequence abstraction optimization on RTL
972 Common Report Var(flag_see) Init(0)
973 Eliminate redundant sign extensions using LCM.
976 Common C ObjC C++ ObjC++ Report Var(flag_show_column) Init(0)
977 Show column numbers in diagnostics, when available. Default off
980 Common Report Var(flag_signaling_nans) Optimization
981 Disable optimizations observable by IEEE signaling NaNs
984 Common Report Var(flag_signed_zeros) Init(1) Optimization
985 Disable floating point optimizations that ignore the IEEE signedness of zero
987 fsingle-precision-constant
988 Common Report Var(flag_single_precision_constant) Optimization
989 Convert floating point constants to single precision constants
991 fsplit-ivs-in-unroller
992 Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
993 Split lifetimes of induction variables when loops are unrolled
996 Common Report Var(flag_split_wide_types) Optimization
997 Split wide types into independent registers
999 fvariable-expansion-in-unroller
1000 Common Report Var(flag_variable_expansion_in_unroller) Optimization
1001 Apply variable expansion when loops are unrolled
1004 Common Report RejectNegative Joined
1005 -fstack-check=[no|generic|specific] Insert stack checking code into the program
1009 Insert stack checking code into the program. Same as -fstack-check=specific
1014 fstack-limit-register=
1015 Common RejectNegative Joined
1016 -fstack-limit-register=<register> Trap if the stack goes past <register>
1018 fstack-limit-symbol=
1019 Common RejectNegative Joined
1020 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>
1023 Common Report Var(flag_stack_protect, 1)
1024 Use propolice as a stack protection method
1026 fstack-protector-all
1027 Common Report RejectNegative Var(flag_stack_protect, 2) VarExists
1028 Use a stack protection method for every function
1032 Does nothing. Preserved for backward compatibility.
1034 ; Nonzero if we should do (language-dependent) alias analysis.
1035 ; Typically, this analysis will assume that expressions of certain
1036 ; types do not alias expressions of certain other types. Only used
1037 ; if alias analysis (in general) is enabled.
1039 Common Report Var(flag_strict_aliasing) Optimization
1040 Assume strict aliasing rules apply
1043 Common Report Var(flag_strict_overflow)
1044 Treat signed overflow as undefined
1047 Common Report Var(flag_syntax_only)
1048 Check for syntax errors, then stop
1051 Common Report Var(flag_test_coverage)
1052 Create data files needed by \"gcov\"
1055 Common Report Var(flag_thread_jumps) Optimization
1056 Perform jump threading optimizations
1059 Common Report Var(time_report)
1060 Report the time taken by each compiler pass
1063 Common Joined RejectNegative
1064 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model
1067 Common Report Var(flag_toplevel_reorder) Init(2) Optimization
1068 Reorder top level functions, variables, and asms
1071 Common Report Var(flag_tracer)
1072 Perform superblock formation via tail duplication
1074 ; Zero means that floating-point math operations cannot generate a
1075 ; (user-visible) trap. This is the case, for example, in nonstop
1076 ; IEEE 754 arithmetic.
1078 Common Report Var(flag_trapping_math) Init(1) Optimization
1079 Assume floating-point operations can trap
1082 Common Report Var(flag_trapv) Optimization
1083 Trap for signed overflow in addition, subtraction and multiplication
1086 Common Report Var(flag_tree_ccp) Optimization
1087 Enable SSA-CCP optimization on trees
1090 Common Report Var(flag_tree_store_ccp) Optimization
1091 Enable SSA-CCP optimization for stores and loads
1094 Common Report Var(flag_tree_ch) Optimization
1095 Enable loop header copying on trees
1098 Common Report Var(flag_tree_copyrename) Optimization
1099 Replace SSA temporaries with better names in copies
1102 Common Report Var(flag_tree_copy_prop) Optimization
1103 Enable copy propagation on trees
1105 ftree-store-copy-prop
1107 Does nothing. Preserved for backward compatibility.
1110 Common Report Var(flag_tree_cselim) Init(2) Optimization
1111 Transform condition stores into unconditional ones
1113 ftree-switch-conversion
1114 Common Report Var(flag_tree_switch_conversion) Optimization
1115 Perform conversions of switch initializations.
1118 Common Report Var(flag_tree_dce) Optimization
1119 Enable SSA dead code elimination optimization on trees
1121 ftree-dominator-opts
1122 Common Report Var(flag_tree_dom) Optimization
1123 Enable dominator optimizations
1126 Common Report Var(flag_tree_dse) Optimization
1127 Enable dead store elimination
1130 Common Report Var(flag_tree_fre) Optimization
1131 Enable Full Redundancy Elimination (FRE) on trees
1133 ftree-loop-distribution
1134 Common Report Var(flag_tree_loop_distribution) Optimization
1135 Enable loop distribution on trees
1138 Common Report Var(flag_tree_loop_im) Init(1) Optimization
1139 Enable loop invariant motion on trees
1142 Common Report Var(flag_tree_loop_linear) Optimization
1143 Enable linear loop transforms on trees
1146 Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
1147 Create canonical induction variables in loops
1150 Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
1151 Enable loop optimizations on tree level
1153 ftree-parallelize-loops=
1154 Common Report Joined UInteger Var(flag_tree_parallelize_loops) Init(1)
1155 Enable automatic parallelization of loops
1158 Common Report Var(flag_tree_pre) Optimization
1159 Enable SSA-PRE optimization on trees
1162 Common Report Var(flag_tree_reassoc) Init(1) Optimization
1163 Enable reassociation on tree level
1167 Does nothing. Preserved for backward compatibility.
1170 Common Report Var(flag_tree_sink) Optimization
1171 Enable SSA code sinking on trees
1174 Common Report Var(flag_tree_sra) Optimization
1175 Perform scalar replacement of aggregates
1178 Common Report Var(flag_tree_ter) Init(1) Optimization
1179 Replace temporary expressions in the SSA->normal pass
1182 Common Report Var(flag_tree_live_range_split) Optimization
1183 Perform live range splitting during the SSA->normal pass
1186 Common Report Var(flag_tree_vrp) Init(0) Optimization
1187 Perform Value Range Propagation on trees
1190 Common Report Var(flag_unit_at_a_time) Init(1) Optimization
1191 Compile whole compilation unit at a time
1194 Common Report Var(flag_unroll_loops) Optimization
1195 Perform loop unrolling when iteration count is known
1198 Common Report Var(flag_unroll_all_loops) Optimization
1199 Perform loop unrolling for all loops
1201 ; Nonzero means that loop optimizer may assume that the induction variables
1202 ; that control loops do not overflow and that the loops with nontrivial
1203 ; exit condition are not infinite
1204 funsafe-loop-optimizations
1205 Common Report Var(flag_unsafe_loop_optimizations) Optimization
1206 Allow loop optimizations to assume that the loops behave in normal way
1209 Common Report Var(flag_associative_math)
1210 Allow optimization for floating-point arithmetic which may change the
1211 result of the operation due to rounding.
1214 Common Report Var(flag_reciprocal_math)
1215 Same as -fassociative-math for expressions which include division.
1217 ; Nonzero means that unsafe floating-point math optimizations are allowed
1218 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
1219 ; are allowed to assume that their arguments and results are "normal"
1220 ; (e.g., nonnegative for SQRT).
1221 funsafe-math-optimizations
1222 Common Report Var(flag_unsafe_math_optimizations) Optimization
1223 Allow math optimizations that may violate IEEE or ISO standards
1226 Common Report Var(flag_unswitch_loops) Optimization
1227 Perform loop unswitching
1230 Common Report Var(flag_unwind_tables) Optimization
1231 Just generate unwind tables for exception handling
1234 Common Report Var(flag_var_tracking) VarExists Optimization
1235 Perform variable tracking
1237 fvar-tracking-uninit
1238 Common Report Var(flag_var_tracking_uninit) Optimization
1239 Perform variable tracking and also tag variables that are uninitialized
1242 Common Report Var(flag_tree_vectorize) Optimization
1243 Enable loop vectorization on trees
1246 Common Report Var(flag_vect_cost_model) Optimization
1247 Enable use of cost model in vectorization
1249 ftree-vect-loop-version
1250 Common Report Var(flag_tree_vect_loop_version) Init(1) Optimization
1251 Enable loop versioning when doing loop vectorization on trees
1253 ftree-vectorizer-verbose=
1254 Common RejectNegative Joined
1255 -ftree-vectorizer-verbose=<number> Set the verbosity level of the vectorizer
1258 Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
1259 Enable copy propagation of scalar-evolution information.
1261 ; -fverbose-asm causes extra commentary information to be produced in
1262 ; the generated assembly code (to make it more readable). This option
1263 ; is generally only of use to those who actually need to read the
1264 ; generated assembly code (perhaps while debugging the compiler itself).
1265 ; -fno-verbose-asm, the default, causes the extra information
1266 ; to not be added and is useful when comparing two assembler files.
1268 Common Report Var(flag_verbose_asm)
1269 Add extra commentary to assembler output
1272 Common Joined RejectNegative
1273 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility
1277 Common Report Var(flag_value_profile_transformations) Optimization
1278 Use expression value profiles in optimizations
1281 Common Report Var(flag_web) Init(2) Optimization
1282 Construct webs and split unrelated uses of single variable
1284 ftree-builtin-call-dce
1285 Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization
1286 Enable conditional dead code elimination for builtin calls
1289 Common Report Var(flag_whole_program) Init(0) Optimization
1290 Perform whole program optimizations
1293 Common Report Var(flag_wrapv) Optimization
1294 Assume signed arithmetic overflow wraps around
1296 fzero-initialized-in-bss
1297 Common Report Var(flag_zero_initialized_in_bss) Init(1)
1298 Put zero initialized data in the bss section
1301 Common JoinedOrMissing
1302 Generate debug information in default format
1305 Common JoinedOrMissing Negative(gdwarf-2)
1306 Generate debug information in COFF format
1309 Common JoinedOrMissing Negative(gstabs)
1310 Generate debug information in DWARF v2 format
1313 Common JoinedOrMissing
1314 Generate debug information in default extended format
1317 Common JoinedOrMissing Negative(gstabs+)
1318 Generate debug information in STABS format
1321 Common JoinedOrMissing Negative(gvms)
1322 Generate debug information in extended STABS format
1325 Common JoinedOrMissing Negative(gxcoff)
1326 Generate debug information in VMS format
1329 Common JoinedOrMissing Negative(gxcoff+)
1330 Generate debug information in XCOFF format
1333 Common JoinedOrMissing Negative(gcoff)
1334 Generate debug information in extended XCOFF format
1337 Common Joined Separate
1338 -o <file> Place output into <file>
1341 Common Var(profile_flag)
1342 Enable function profiling
1345 Common Var(pedantic)
1346 Issue warnings needed for strict compliance to the standard
1350 Like -pedantic but issue them as errors
1353 Common Var(quiet_flag)
1354 Do not display functions compiled or elapsed time
1357 Common Var(version_flag)
1358 Display the compiler's version
1361 Common Var(inhibit_warnings)
1365 Common RejectNegative Negative(pie)
1366 Create a shared library
1369 Common RejectNegative Negative(shared)
1370 Create a position independent executable
1372 ; This comment is to ensure we retain the blank line above.