1 ; Options for the language- and target-independent parts of the compiler.
3 ; Copyright (C) 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
5 ; This file is part of GCC.
7 ; GCC is free software; you can redistribute it and/or modify it under
8 ; the terms of the GNU General Public License as published by the Free
9 ; Software Foundation; either version 2, or (at your option) any later
12 ; GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 ; WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 ; FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 ; You should have received a copy of the GNU General Public License
18 ; along with GCC; see the file COPYING. If not, write to the Free
19 ; Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
22 ; See the GCC internals manual 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
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
98 Common Var(warnings_are_errors)
99 Treat all warnings as errors
103 Treat specified warning as error
107 Print extra (possibly unwanted) warnings
110 Common Var(flag_fatal_errors)
111 Exit on the first error occurred
114 Common Var(warn_inline) Warning
115 Warn when an inlined function cannot be inlined
118 Common RejectNegative Joined UInteger Warning
119 -Wlarger-than-<number> Warn if an object is larger than <number> bytes
122 Common Warning Var(warn_logical_op)
123 Warn when a logical operator is suspicously always evaluating to true or false
125 Wunsafe-loop-optimizations
126 Common Var(warn_unsafe_loop_optimizations) Warning
127 Warn if the loop cannot be optimized due to nontrivial assumptions.
130 Common Var(warn_missing_noreturn) Warning
131 Warn about functions which might be candidates for __attribute__((noreturn))
134 Common Var(warn_overflow) Init(1) Warning
135 Warn about overflow in arithmetic expressions
138 Common Var(warn_packed) Warning
139 Warn when the packed attribute has no effect on struct layout
142 Common Var(warn_padded) Warning
143 Warn when padding is required to align structure members
146 Common Var(warn_shadow) Warning
147 Warn when one local variable shadows another
150 Common Var(warn_stack_protect) Warning
151 Warn when not issuing stack smashing protection for some reason
155 Warn about code which might break strict aliasing rules
158 Common Joined UInteger Warning
159 Warn about code which might break strict aliasing rules
163 Warn about optimizations that assume that signed overflow is undefined
166 Common Joined UInteger Warning
167 Warn about optimizations that assume that signed overflow is undefined
170 Common Var(warn_switch) Warning
171 Warn about enumerated switches, with no default, missing a case
174 Common Var(warn_switch_default) Warning
175 Warn about enumerated switches missing a \"default:\" statement
178 Common Var(warn_switch_enum) Warning
179 Warn about all enumerated switches missing a specific case
182 Common Var(warn_system_headers) Warning
183 Do not suppress warnings from system headers
186 Common Var(warn_uninitialized) Warning
187 Warn about uninitialized automatic variables
190 Common Var(warn_notreached) Warning
191 Warn about code that will never be executed
195 Enable all -Wunused- warnings
198 Common Var(warn_unused_function) Warning
199 Warn when a function is unused
202 Common Var(warn_unused_label) Warning
203 Warn when a label is unused
206 Common Var(warn_unused_parameter) Warning
207 Warn when a function parameter is unused
210 Common Var(warn_unused_value) Warning
211 Warn when an expression value is unused
214 Common Var(warn_unused_variable) Warning
215 Warn when a variable is unused
217 Wvolatile-register-var
218 Common Var(warn_register_var) Warning
219 Warn when a register variable is declared volatile
222 Common RejectNegative Var(warn_coverage_mismatch) Warning
223 Warn instead of error in case profiles in -fprofile-use do not match
227 -aux-info <file> Emit declaration information into <file>
240 -d<letters> Enable dumps from specific passes of the compiler
244 -dumpbase <file> Set the file basename to be used for dumps
246 ; The version of the C++ ABI in use. The following values are allowed:
248 ; 0: The version of the ABI believed most conformant with the C++ ABI
249 ; specification. This ABI may change as bugs are discovered and fixed.
250 ; Therefore, 0 will not necessarily indicate the same ABI in different
253 ; 1: The version of the ABI first used in G++ 3.2.
255 ; Additional positive integers will be assigned as new versions of
256 ; the ABI become the default version of the ABI.
258 Common Joined UInteger Var(flag_abi_version) Init(2)
261 Common Report Var(align_functions,0)
262 Align the start of functions
265 Common RejectNegative Joined UInteger
268 Common Report Var(align_jumps,0) Optimization
269 Align labels which are only reached by jumping
272 Common RejectNegative Joined UInteger
275 Common Report Var(align_labels,0) Optimization
279 Common RejectNegative Joined UInteger
282 Common Report Var(align_loops) Optimization
283 Align the start of loops
286 Common RejectNegative Joined UInteger
288 ; This flag is only tested if alias checking is enabled.
289 ; 0 if pointer arguments may alias each other. True in C.
290 ; 1 if pointer arguments may not alias each other but may alias
292 ; 2 if pointer arguments may not alias each other and may not
293 ; alias global variables.
294 ; 3 if pointer arguments may not alias anything. True in Fortran.
295 ; Set by the front end.
297 Common Report Var(flag_argument_noalias,0) Optimization
298 Specify that arguments may alias each other and globals
301 Common Report Var(flag_argument_noalias,1) VarExists Optimization
302 Assume arguments may alias globals but not each other
304 fargument-noalias-global
305 Common Report Var(flag_argument_noalias,2) VarExists Optimization
306 Assume arguments alias neither each other nor globals
308 fargument-noalias-anything
309 Common Report Var(flag_argument_noalias,3) VarExists Optimization
310 Assume arguments alias no other storage
312 fasynchronous-unwind-tables
313 Common Report Var(flag_asynchronous_unwind_tables) Optimization
314 Generate unwind tables that are exact at each instruction boundary
316 ; -fcheck-bounds causes gcc to generate array bounds checks.
317 ; For C, C++ and ObjC: defaults off.
318 ; For Java: defaults to on.
319 ; For Fortran: defaults to off.
321 Common Report Var(flag_bounds_check)
322 Generate code to check bounds before indexing arrays
325 Common Report Var(flag_branch_on_count_reg) Init(1) Optimization
326 Replace add, compare, branch with branch on count register
328 fbranch-probabilities
329 Common Report Var(flag_branch_probabilities) Optimization
330 Use profiling information for branch probabilities
332 fbranch-target-load-optimize
333 Common Report Var(flag_branch_target_load_optimize) Optimization
334 Perform branch target load optimization before prologue / epilogue threading
336 fbranch-target-load-optimize2
337 Common Report Var(flag_branch_target_load_optimize2) Optimization
338 Perform branch target load optimization after prologue / epilogue threading
341 Common Report Var(flag_btr_bb_exclusive) Optimization
342 Restrict target load migration not to re-use registers in any basic block
345 Common Joined RejectNegative
346 -fcall-saved-<register> Mark <register> as being preserved across functions
349 Common Joined RejectNegative
350 -fcall-used-<register> Mark <register> as being corrupted by function calls
352 ; Nonzero for -fcaller-saves: allocate values in regs that need to
353 ; be saved across function calls, if that produces overall better code.
354 ; Optional now, so people can test it.
356 Common Report Var(flag_caller_saves) Optimization
357 Save registers around function calls
360 Common Report Var(flag_check_data_deps)
361 Compare the results of several data dependence analyzers.
364 Common Report Var(flag_no_common,0) Optimization
365 Do not put uninitialized globals in the common section
368 Common Report Var(flag_cprop_registers) Optimization
369 Perform a register copy-propagation optimization pass
372 Common Report Var(flag_crossjumping) Optimization
373 Perform cross-jumping optimization
376 Common Report Var(flag_cse_follow_jumps) Optimization
377 When running CSE, follow jumps to their targets
380 Common Report Var(flag_cse_skip_blocks) Optimization
381 When running CSE, follow conditional jumps
384 Common Report Var(flag_cx_limited_range) Optimization
385 Omit range reduction step when performing complex division
388 Common Report Var(flag_data_sections) Optimization
389 Place data items into their own section
391 ; Nonzero for -fdefer-pop: don't pop args after each function call
392 ; instead save them up to pop many calls' args with one insns.
394 Common Report Var(flag_defer_pop) Optimization
395 Defer popping functions args from stack until later
398 Common Report Var(flag_delayed_branch) Optimization
399 Attempt to fill delay slots of branch instructions
401 fdelete-null-pointer-checks
402 Common Report Var(flag_delete_null_pointer_checks) Optimization
403 Delete useless null pointer checks
405 fdiagnostics-show-location=
406 Common Joined RejectNegative
407 -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics
409 fdiagnostics-show-option
411 Amend appropriate diagnostic messages with the command line option that controls them
414 Common Joined RejectNegative
415 -fdump-<type> Dump various compiler internals to a file
418 Common Report Var(flag_dump_noaddr)
419 Suppress output of addresses in debugging dumps
422 Common Report Var(flag_dump_unnumbered) VarExists
423 Suppress output of instruction numbers, line number notes and addresses in debugging dumps
426 Common Report Var(flag_early_inlining) Init(1) Optimization
427 Perform early inlining
429 feliminate-dwarf2-dups
430 Common Report Var(flag_eliminate_dwarf2_dups)
431 Perform DWARF2 duplicate elimination
433 feliminate-unused-debug-symbols
434 Common Report Var(flag_debug_only_used_symbols)
435 Perform unused type elimination in debug info
437 feliminate-unused-debug-types
438 Common Report Var(flag_eliminate_unused_debug_types) Init(1)
439 Perform unused type elimination in debug info
441 femit-class-debug-always
442 Common Report Var(flag_emit_class_debug_always) Init(1)
443 Do not suppress C++ class debug information.
446 Common Report Var(flag_exceptions) Optimization
447 Enable exception handling
449 fexpensive-optimizations
450 Common Report Var(flag_expensive_optimizations) Optimization
451 Perform a number of minor, expensive optimizations
457 Common Report Var(flag_finite_math_only) Optimization
458 Assume no NaNs or infinities are generated
461 Common Joined RejectNegative
462 -ffixed-<register> Mark <register> as being unavailable to the compiler
465 Common Report Var(flag_float_store) Optimization
466 Don't allocate floats and doubles in extended-precision registers
468 ; Nonzero for -fforce-addr: load memory address into a register before
469 ; reference to memory. This makes better cse but slower compilation.
471 Common Report Var(flag_force_addr) Optimization
472 Copy memory address constants into registers before use
475 Common Report Var(flag_forward_propagate) Optimization
476 Perform a forward propagation pass on RTL
478 ; Nonzero means don't put addresses of constant functions in registers.
479 ; Used for compiling the Unix kernel, where strange substitutions are
480 ; done on the assembly output.
482 Common Report Var(flag_no_function_cse,0)
483 Allow function addresses to be held in registers
486 Common Report Var(flag_function_sections)
487 Place each function into its own section
490 Common Report Var(flag_gcse) Optimization
491 Perform global common subexpression elimination
494 Common Report Var(flag_gcse_lm) Init(1) Optimization
495 Perform enhanced load motion during global common subexpression elimination
498 Common Report Var(flag_gcse_sm) Init(0) Optimization
499 Perform store motion after global common subexpression elimination
502 Common Report Var(flag_gcse_las) Init(0) Optimization
503 Perform redundant load after store elimination in global common subexpression
507 Common Report Var(flag_gcse_after_reload) Optimization
508 Perform global common subexpression elimination after register allocation
511 fguess-branch-probability
512 Common Report Var(flag_guess_branch_prob) Optimization
513 Enable guessing of branch probabilities
515 ; Nonzero means ignore `#ident' directives. 0 means handle them.
516 ; Generate position-independent code for executables if possible
517 ; On SVR4 targets, it also controls whether or not to emit a
518 ; string identifying the compiler.
520 Common Report Var(flag_no_ident,0)
521 Process #ident directives
524 Common Report Var(flag_if_conversion) Optimization
525 Perform conversion of conditional jumps to branchless equivalents
528 Common Report Var(flag_if_conversion2) Optimization
529 Perform conversion of conditional jumps to conditional execution
531 ; -finhibit-size-directive inhibits output of .size for ELF.
532 ; This is used only for compiling crtstuff.c,
533 ; and it may be extended to other effects
534 ; needed for crtstuff.c on other systems.
535 finhibit-size-directive
536 Common Report Var(flag_inhibit_size_directive)
537 Do not generate .size directives
539 ; Nonzero means that functions declared `inline' will be treated
540 ; as `static'. Prevents generation of zillions of copies of unused
541 ; static inline functions; instead, `inlines' are written out
542 ; only when actually used. Used in conjunction with -g. Also
543 ; does the right thing with #pragma interface.
545 Common Report Var(flag_no_inline,0) Init(2)
546 Pay attention to the \"inline\" keyword
549 Common Report Var(flag_inline_functions) Optimization
550 Integrate simple functions into their callers
552 finline-functions-called-once
553 Common Report Var(flag_inline_functions_called_once) Init(1) Optimization
554 Integrate functions called once into their callers
557 Common RejectNegative Joined UInteger
560 Common RejectNegative Joined UInteger
561 -finline-limit=<number> Limit the size of inlined functions to <number>
563 finstrument-functions
564 Common Report Var(flag_instrument_function_entry_exit)
565 Instrument function entry and exit with profiling calls
568 Common Report Var(flag_ipa_cp) Optimization
569 Perform Interprocedural constant propagation
572 Common Report Var(flag_ipa_pure_const) Init(0) Optimization
573 Discover pure and const functions
576 Common Report Var(flag_ipa_pta) Init(0) Optimization
577 Perform interprocedural points-to analysis
580 Common Report Var(flag_ipa_reference) Init(0) Optimization
581 Discover readonly and non addressable static variables
584 Common Report Var(flag_ipa_type_escape) Init(0) Optimization
585 Type based escape and alias analysis
588 Common Report Var(flag_ipa_matrix_reorg)
589 Perform matrix layout flattening and transposing based
590 on profiling information.
593 Common Report Var(flag_ivopts) Init(1) Optimization
594 Optimize induction variables on trees
597 Common Var(flag_jump_tables) Init(1) Optimization
598 Use jump tables for sufficiently large switch statements
600 fkeep-inline-functions
601 Common Report Var(flag_keep_inline_functions)
602 Generate code for functions even if they are fully inlined
605 Common Report Var(flag_keep_static_consts) Init(1)
606 Emit static const variables even if they are not used
609 Common Report Var(flag_leading_underscore) Init(-1)
610 Give external symbols a leading underscore
614 Does nothing. Preserved for backward compatibility.
617 Common Report Var(flag_errno_math) Init(1)
618 Set errno after built-in math functions
621 Common Report Var(mem_report)
622 Report on permanent memory allocation
624 ; This will attempt to merge constant section constants, if 1 only
625 ; string constants and constants from constant pool, if 2 also constant
628 Common Report Var(flag_merge_constants,2) Init(1) Optimization
629 Attempt to merge identical constants and constant variables
632 Common Report Var(flag_merge_constants,1) VarExists Optimization
633 Attempt to merge identical constants across compilation units
636 Common RejectNegative Joined UInteger
637 -fmessage-length=<number> Limit diagnostics to <number> characters per line. 0 suppresses line-wrapping
640 Common Report Var(flag_modulo_sched) Optimization
641 Perform SMS based modulo scheduling before the first scheduling pass
643 fmove-loop-invariants
644 Common Report Var(flag_move_loop_invariants) Init(1) Optimization
645 Move loop invariant computations out of loops
648 Common RejectNegative Report Var(flag_mudflap)
649 Add mudflap bounds-checking instrumentation for single-threaded program
652 Common RejectNegative Report VarExists Var(flag_mudflap,2)
653 Add mudflap bounds-checking instrumentation for multi-threaded program
656 Common RejectNegative Report Var(flag_mudflap_ignore_reads)
657 Ignore read operations when inserting mudflap instrumentation
659 freschedule-modulo-scheduled-loops
660 Common Report Var(flag_resched_modulo_sched) Optimization
661 Enable/Disable the traditional scheduling in loops that already passed modulo scheduling
664 Common Report Var(flag_non_call_exceptions) Optimization
665 Support synchronous non-call exceptions
668 Common Report Var(flag_omit_frame_pointer) Optimization
669 When possible do not generate stack frames
671 foptimize-register-move
672 Common Report Var(flag_regmove) Optimization
673 Do the full register move optimization pass
675 foptimize-sibling-calls
676 Common Report Var(flag_optimize_sibling_calls) Optimization
677 Optimize sibling and tail recursive calls
680 Common Report Var(pre_ipa_mem_report)
681 Report on memory allocation before interprocedural optimization
684 Common Report Var(post_ipa_mem_report)
685 Report on memory allocation before interprocedural optimization
688 Common Report Var(flag_pack_struct) Optimization
689 Pack structure members together without holes
692 Common RejectNegative Joined UInteger Optimization
693 -fpack-struct=<number> Set initial maximum structure member alignment
696 Common Report Var(flag_pcc_struct_return,1) VarExists
697 Return small aggregates in memory, not registers
700 Common Report Var(flag_peel_loops) Optimization
704 Common Report Var(flag_no_peephole,0) Optimization
705 Enable machine specific peephole optimizations
708 Common Report Var(flag_peephole2) Optimization
709 Enable an RTL peephole pass before sched2
712 Common Report Var(flag_pic,2)
713 Generate position-independent code if possible (large mode)
716 Common Report Var(flag_pie,2)
717 Generate position-independent code for executables if possible (large mode)
720 Common Report Var(flag_pic,1) VarExists
721 Generate position-independent code if possible (small mode)
724 Common Report Var(flag_pie,1) VarExists
725 Generate position-independent code for executables if possible (small mode)
727 fpredictive-commoning
728 Common Report Var(flag_predictive_commoning)
729 Run predictive commoning optimization.
731 fprefetch-loop-arrays
732 Common Report Var(flag_prefetch_loop_arrays) Optimization
733 Generate prefetch instructions, if available, for arrays in loops
736 Common Report Var(profile_flag)
737 Enable basic program profiling code
740 Common Report Var(profile_arc_flag)
741 Insert arc-based program profiling code
745 Enable common options for generating profile info for profile feedback directed optimizations
749 Enable common options for performing profile feedback directed optimizations
752 Common Report Var(flag_profile_values)
753 Insert code to profile values of expressions
759 Common Joined RejectNegative
760 -frandom-seed=<string> Make compile reproducible using <string>
762 ; This switch causes the command line that was used to create an
763 ; object file to be recorded into the object file. The exact format
764 ; of this recording is target and binary file format dependent.
765 ; It is related to the -fverbose-asm switch, but that switch only
766 ; records information in the assembler output file as comments, so
767 ; they never reach the object file.
769 Common Report Var(flag_record_gcc_switches)
770 Record gcc command line switches in the object file.
773 Common Report Var(flag_pcc_struct_return,0) VarExists Optimization
774 Return small aggregates in registers
777 Common Report Var(flag_regmove) Optimization
778 Enables a register move optimization
781 Common Report Var(flag_rename_registers) Init(2) Optimization
782 Perform a register renaming optimization pass
785 Common Report Var(flag_reorder_blocks) Optimization
786 Reorder basic blocks to improve code placement
788 freorder-blocks-and-partition
789 Common Report Var(flag_reorder_blocks_and_partition) Optimization
790 Reorder basic blocks and partition into hot and cold sections
793 Common Report Var(flag_reorder_functions) Optimization
794 Reorder functions to improve code placement
796 frerun-cse-after-loop
797 Common Report Var(flag_rerun_cse_after_loop) Init(2) Optimization
798 Add a common subexpression elimination pass after loop optimizations
802 Does nothing. Preserved for backward compatibility.
805 Common Report Var(flag_rounding_math) Optimization
806 Disable optimizations that assume default FP rounding behavior
809 Common Report Var(flag_schedule_interblock) Init(1) Optimization
810 Enable scheduling across basic blocks
813 Common Report Var(flag_schedule_speculative) Init(1) Optimization
814 Allow speculative motion of non-loads
817 Common Report Var(flag_schedule_speculative_load) Optimization
818 Allow speculative motion of some loads
820 fsched-spec-load-dangerous
821 Common Report Var(flag_schedule_speculative_load_dangerous) Optimization
822 Allow speculative motion of more loads
825 Common RejectNegative Joined
826 -fsched-verbose=<number> Set the verbosity level of the scheduler
828 fsched2-use-superblocks
829 Common Report Var(flag_sched2_use_superblocks) Optimization
830 If scheduling post reload, do superblock scheduling
833 Common Report Var(flag_sched2_use_traces) Optimization
834 If scheduling post reload, do trace scheduling
837 Common Report Var(flag_schedule_insns) Optimization
838 Reschedule instructions before register allocation
841 Common Report Var(flag_schedule_insns_after_reload) Optimization
842 Reschedule instructions after register allocation
844 ; sched_stalled_insns means that insns can be moved prematurely from the queue
845 ; of stalled insns into the ready list.
847 Common Report Var(flag_sched_stalled_insns) Optimization
848 Allow premature scheduling of queued insns
850 fsched-stalled-insns=
851 Common RejectNegative Joined UInteger
852 -fsched-stalled-insns=<number> Set number of queued insns that can be prematurely scheduled
854 ; sched_stalled_insns_dep controls how many recently scheduled cycles will
855 ; be examined for a dependency on a stalled insn that is candidate for
856 ; premature removal from the queue of stalled insns into the ready list (has
857 ; an effect only if the flag 'sched_stalled_insns' is set).
858 fsched-stalled-insns-dep
859 Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization
860 Set dependence distance checking in premature scheduling of queued insns
862 fsched-stalled-insns-dep=
863 Common RejectNegative Joined UInteger
864 -fsched-stalled-insns-dep=<number> Set dependence distance checking in premature scheduling of queued insns
867 Common Report Var(flag_section_anchors) Optimization
868 Access data in the same section from shared anchor points
870 frtl-abstract-sequences
871 Common Report Var(flag_rtl_seqabstr) Optimization
872 Perform sequence abstraction optimization on RTL
875 Common Report Var(flag_see) Init(0)
876 Eliminate redundant sign extensions using LCM.
879 Common C ObjC C++ ObjC++ Report Var(flag_show_column) Init(1)
880 Show column numbers in diagnostics, when available. Default on
883 Common Report Var(flag_signaling_nans) Optimization
884 Disable optimizations observable by IEEE signaling NaNs
887 Common Report Var(flag_signed_zeros) Init(1) Optimization
888 Disable floating point optimizations that ignore the IEEE signedness of zero
890 fsingle-precision-constant
891 Common Report Var(flag_single_precision_constant) Optimization
892 Convert floating point constants to single precision constants
894 fsplit-ivs-in-unroller
895 Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization
896 Split lifetimes of induction variables when loops are unrolled
899 Common Report Var(flag_split_wide_types) Optimization
900 Split wide types into independent registers
902 fvariable-expansion-in-unroller
903 Common Report Var(flag_variable_expansion_in_unroller) Optimization
904 Apply variable expansion when loops are unrolled
906 ; Emit code to probe the stack, to help detect stack overflow; also
907 ; may cause large objects to be allocated dynamically.
909 Common Report Var(flag_stack_check)
910 Insert stack checking code into the program
915 fstack-limit-register=
916 Common RejectNegative Joined
917 -fstack-limit-register=<register> Trap if the stack goes past <register>
920 Common RejectNegative Joined
921 -fstack-limit-symbol=<name> Trap if the stack goes past symbol <name>
924 Common Report Var(flag_stack_protect, 1)
925 Use propolice as a stack protection method
928 Common Report RejectNegative Var(flag_stack_protect, 2) VarExists
929 Use a stack protection method for every function
933 Does nothing. Preserved for backward compatibility.
935 ; Nonzero if we should do (language-dependent) alias analysis.
936 ; Typically, this analysis will assume that expressions of certain
937 ; types do not alias expressions of certain other types. Only used
938 ; if alias analysis (in general) is enabled.
940 Common Report Var(flag_strict_aliasing) Optimization
941 Assume strict aliasing rules apply
944 Common Report Var(flag_strict_overflow)
945 Treat signed overflow as undefined
948 Common Report Var(flag_syntax_only)
949 Check for syntax errors, then stop
952 Common Report Var(flag_test_coverage)
953 Create data files needed by \"gcov\"
956 Common Report Var(flag_thread_jumps) Optimization
957 Perform jump threading optimizations
960 Common Report Var(time_report)
961 Report the time taken by each compiler pass
964 Common Joined RejectNegative
965 -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model
968 Common Report Var(flag_toplevel_reorder) Init(1) Optimization
969 Reorder top level functions, variables, and asms
972 Common Report Var(flag_tracer)
973 Perform superblock formation via tail duplication
975 ; Zero means that floating-point math operations cannot generate a
976 ; (user-visible) trap. This is the case, for example, in nonstop
977 ; IEEE 754 arithmetic.
979 Common Report Var(flag_trapping_math) Init(1) Optimization
980 Assume floating-point operations can trap
983 Common Report Var(flag_trapv) Optimization
984 Trap for signed overflow in addition, subtraction and multiplication
987 Common Report Var(flag_tree_ccp) Optimization
988 Enable SSA-CCP optimization on trees
991 Common Report Var(flag_tree_store_ccp) Optimization
992 Enable SSA-CCP optimization for stores and loads
995 Common Report Var(flag_tree_ch) Optimization
996 Enable loop header copying on trees
999 Common Report Var(flag_tree_copyrename) Optimization
1000 Replace SSA temporaries with better names in copies
1003 Common Report Var(flag_tree_copy_prop) Optimization
1004 Enable copy propagation on trees
1006 ftree-store-copy-prop
1007 Common Report Var(flag_tree_store_copy_prop) Optimization
1008 Enable copy propagation for stores and loads
1011 Common Report Var(flag_tree_dce) Optimization
1012 Enable SSA dead code elimination optimization on trees
1014 ftree-dominator-opts
1015 Common Report Var(flag_tree_dom) Optimization
1016 Enable dominator optimizations
1019 Common Report Var(flag_tree_dse) Optimization
1020 Enable dead store elimination
1023 Common Report Var(flag_tree_fre) Optimization
1024 Enable Full Redundancy Elimination (FRE) on trees
1027 Common Report Var(flag_tree_loop_im) Init(1) Optimization
1028 Enable loop invariant motion on trees
1031 Common Report Var(flag_tree_loop_linear) Optimization
1032 Enable linear loop transforms on trees
1035 Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization
1036 Create canonical induction variables in loops
1039 Common Report Var(flag_tree_loop_optimize) Init(1) Optimization
1040 Enable loop optimizations on tree level
1043 Common Report Var(flag_tree_pre) Optimization
1044 Enable SSA-PRE optimization on trees
1047 Common Report Var(flag_tree_salias) Optimization
1048 Perform structural alias analysis
1051 Common Report Var(flag_tree_sink) Optimization
1052 Enable SSA code sinking on trees
1055 Common Report Var(flag_tree_sra) Optimization
1056 Perform scalar replacement of aggregates
1059 Common Report Var(flag_tree_ter) Optimization
1060 Replace temporary expressions in the SSA->normal pass
1063 Common Report Var(flag_tree_live_range_split) Optimization
1064 Perform live range splitting during the SSA->normal pass
1067 Common Report Var(flag_tree_vrp) Init(0) Optimization
1068 Perform Value Range Propagation on trees
1071 Common Report Var(flag_unit_at_a_time) Optimization
1072 Compile whole compilation unit at a time
1075 Common Report Var(flag_unroll_loops) Optimization
1076 Perform loop unrolling when iteration count is known
1079 Common Report Var(flag_unroll_all_loops) Optimization
1080 Perform loop unrolling for all loops
1082 ; Nonzero means that loop optimizer may assume that the induction variables
1083 ; that control loops do not overflow and that the loops with nontrivial
1084 ; exit condition are not infinite
1085 funsafe-loop-optimizations
1086 Common Report Var(flag_unsafe_loop_optimizations) Optimization
1087 Allow loop optimizations to assume that the loops behave in normal way
1089 ; Nonzero means that unsafe floating-point math optimizations are allowed
1090 ; for the sake of speed. IEEE compliance is not guaranteed, and operations
1091 ; are allowed to assume that their arguments and results are "normal"
1092 ; (e.g., nonnegative for SQRT).
1093 funsafe-math-optimizations
1094 Common Report Var(flag_unsafe_math_optimizations) Optimization
1095 Allow math optimizations that may violate IEEE or ISO standards
1098 Common Report Var(flag_unswitch_loops) Optimization
1099 Perform loop unswitching
1102 Common Report Var(flag_unwind_tables) Optimization
1103 Just generate unwind tables for exception handling
1106 Common Report Var(flag_var_tracking) VarExists Optimization
1107 Perform variable tracking
1110 Common Report Var(flag_tree_vectorize) Optimization
1111 Enable loop vectorization on trees
1113 ftree-vect-loop-version
1114 Common Report Var(flag_tree_vect_loop_version) Init(1) Optimization
1115 Enable loop versioning when doing loop vectorization on trees
1117 ftree-vectorizer-verbose=
1118 Common RejectNegative Joined
1119 -ftree-vectorizer-verbose=<number> Set the verbosity level of the vectorizer
1122 Common Report Var(flag_tree_scev_cprop) Init(1) Optimization
1123 Enable copy propagation of scalar-evolution information.
1125 ; -fverbose-asm causes extra commentary information to be produced in
1126 ; the generated assembly code (to make it more readable). This option
1127 ; is generally only of use to those who actually need to read the
1128 ; generated assembly code (perhaps while debugging the compiler itself).
1129 ; -fno-verbose-asm, the default, causes the extra information
1130 ; to not be added and is useful when comparing two assembler files.
1132 Common Report Var(flag_verbose_asm)
1133 Add extra commentary to assembler output
1136 Common Joined RejectNegative
1137 -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility
1141 Common Report Var(flag_value_profile_transformations) Optimization
1142 Use expression value profiles in optimizations
1145 Common Report Var(flag_web) Init(2) Optimization
1146 Construct webs and split unrelated uses of single variable
1149 Common Report Var(flag_whole_program) Init(0) Optimization
1150 Perform whole program optimizations
1153 Common Report Var(flag_wrapv) Optimization
1154 Assume signed arithmetic overflow wraps around
1156 fzero-initialized-in-bss
1157 Common Report Var(flag_zero_initialized_in_bss) Init(1)
1158 Put zero initialized data in the bss section
1161 Common JoinedOrMissing
1162 Generate debug information in default format
1165 Common JoinedOrMissing Negative(gdwarf-2)
1166 Generate debug information in COFF format
1169 Common JoinedOrMissing Negative(gstabs)
1170 Generate debug information in DWARF v2 format
1173 Common JoinedOrMissing
1174 Generate debug information in default extended format
1177 Common JoinedOrMissing Negative(gstabs+)
1178 Generate debug information in STABS format
1181 Common JoinedOrMissing Negative(gvms)
1182 Generate debug information in extended STABS format
1185 Common JoinedOrMissing Negative(gxcoff)
1186 Generate debug information in VMS format
1189 Common JoinedOrMissing Negative(gxcoff+)
1190 Generate debug information in XCOFF format
1193 Common JoinedOrMissing Negative(gcoff)
1194 Generate debug information in extended XCOFF format
1197 Common Joined Separate
1198 -o <file> Place output into <file>
1201 Common Var(profile_flag)
1202 Enable function profiling
1205 Common Var(pedantic)
1206 Issue warnings needed for strict compliance to the standard
1210 Like -pedantic but issue them as errors
1213 Common Var(quiet_flag)
1214 Do not display functions compiled or elapsed time
1217 Common Var(version_flag)
1218 Display the compiler's version
1221 Common Var(inhibit_warnings)
1224 ; This comment is to ensure we retain the blank line above.