@gccoptlist{-d@var{letters} -dumpspecs -dumpmachine -dumpversion @gol
-fdump-unnumbered -fdump-translation-unit@r{[}-@var{n}@r{]} @gol
-fdump-class-hierarchy@r{[}-@var{n}@r{]} @gol
+-fdump-tree-all @gol
-fdump-tree-original@r{[}-@var{n}@r{]} @gol
-fdump-tree-optimized@r{[}-@var{n}@r{]} @gol
-fdump-tree-inlined@r{[}-@var{n}@r{]} @gol
+-fdump-tree-cfg -fdump-tree-vcg -fdump-tree-alias @gol
+-fdump-tree-ch @gol
+-fdump-tree-ssa@r{[}-@var{n}@r{]} -fdump-tree-pre@r{[}-@var{n}@r{]} @gol
+-fdump-tree-ccp@r{[}-@var{n}@r{]} -fdump-tree-dce@r{[}-@var{n}@r{]} @gol
+-fdump-tree-gimple@r{[}-raw@r{]} -fdump-tree-mudflap@r{[}-@var{n}@r{]} @gol
+-fdump-tree-dom@r{[}-@var{n}@r{]} @gol
+-fdump-tree-dse@r{[}-@var{n}@r{]} @gol
+-fdump-tree-phiopt@r{[}-@var{n}@r{]} @gol
+-fdump-tree-forwprop@r{[}-@var{n}@r{]} @gol
+-fdump-tree-copyrename@r{[}-@var{n}@r{]} @gol
+-fdump-tree-nrv @gol
+-fdump-tree-sra@r{[}-@var{n}@r{]} @gol
-feliminate-dwarf2-dups -feliminate-unused-debug-types @gol
--feliminate-unused-debug-symbols -fmem-report -fprofile-arcs @gol
+-feliminate-unused-debug-symbols -fmem-report -fprofile-arcs -ftree-based-profiling @gol
-frandom-seed=@var{string} -fsched-verbose=@var{n} @gol
-ftest-coverage -ftime-report -fvar-tracking @gol
-g -g@var{level} -gcoff -gdwarf-2 @gol
@xref{Optimize Options,,Options that Control Optimization}.
@gccoptlist{-falign-functions=@var{n} -falign-jumps=@var{n} @gol
-falign-labels=@var{n} -falign-loops=@var{n} @gol
+-fbounds-check -fmudflap -fmudflapth -fmudflapir @gol
-fbranch-probabilities -fprofile-values -fvpt -fbranch-target-load-optimize @gol
-fbranch-target-load-optimize2 -fbtr-bb-exclusive @gol
-fcaller-saves -fcprop-registers @gol
-fstrength-reduce -fstrict-aliasing -ftracer -fthread-jumps @gol
-funroll-all-loops -funroll-loops -fpeel-loops @gol
-funswitch-loops -fold-unroll-loops -fold-unroll-all-loops @gol
+-ftree-pre -ftree-ccp -ftree-dce @gol
+-ftree-dominator-opts -ftree-dse -ftree-copyrename @gol
+-ftree-ch -ftree-sra -ftree-ter -ftree-lrs @gol
--param @var{name}=@var{value}
-O -O0 -O1 -O2 -O3 -Os}
Fortran source code which must be preprocessed with a RATFOR
preprocessor (not included with GCC)@.
+@item @var{file}.f90
+@itemx @var{file}.f95
+Fortran 90/95 source code which should not be preprocessed.
+
@xref{Overall Options,,Options Controlling the Kind of Output, g77,
Using and Porting GNU Fortran}, for more details of the handling of
Fortran input files.
assembler assembler-with-cpp
ada
f77 f77-cpp-input ratfor
+f95
java
treelang
@end smallexample
instrumentation code can be added to the block; otherwise, a new basic
block must be created to hold the instrumentation code.
+@item -ftree-based-profiling
+@opindex ftree-based-profiling
+This option is used in addition to @option{-fprofile-arcs} or
+@option{-fbranch-probabilities} to control whether those optimizations
+are performed on a tree-based or rtl-based internal representation.
+If you use this option when compiling with @option{-fprofile-arcs},
+you must also use it when compiling later with @option{-fbranch-probabilities}.
+Currently the tree-based optimization is in an early stage of
+development, and this option is recommended only for those people
+working on improving it.
+
@need 2000
@item -ftest-coverage
@opindex ftest-coverage
@var{options} controls the details of the dump as described for the
@option{-fdump-tree} options.
-@item -fdump-tree-@var{switch} @r{(C++ only)}
-@itemx -fdump-tree-@var{switch}-@var{options} @r{(C++ only)}
+@item -fdump-tree-@var{switch} @r{(C and C++ only)}
+@itemx -fdump-tree-@var{switch}-@var{options} @r{(C and C++ only)}
@opindex fdump-tree
Control the dumping at various stages of processing the intermediate
language tree to a file. The file name is generated by appending a switch
is for tying up a dump file with a debug environment.
@item slim
Inhibit dumping of members of a scope or body of a function merely
-because that scope has been reached. Only dump such items when they
-are directly reachable by some other path.
+because that scope has been reached. Only dump such items when they
+are directly reachable by some other path. When dumping pretty-printed
+trees, this option inhibits dumping the bodies of control structures.
+@item raw
+Print a raw representation of the tree. By default, trees are
+pretty-printed into a C-like representation.
+@item details
+Enable more detailed dumps (not honored by every dump option).
+@item stats
+Enable dumping various statistics about the pass (not honored by every dump
+option).
+@item blocks
+Enable showing basic block boundaries (disabled in raw dumps).
+@item vops
+Enable showing virtual operands for every statement.
+@item lineno
+Enable showing line numbers for statements.
+@item uid
+Enable showing the unique ID (@code{DECL_UID}) for each variable.
@item all
-Turn on all options.
+Turn on all options, except @option{raw}, @option{slim} and @option{lineno}.
@end table
The following tree dumps are possible:
@table @samp
+
@item original
Dump before any tree based optimization, to @file{@var{file}.original}.
+
@item optimized
Dump after all tree based optimization, to @file{@var{file}.optimized}.
+
@item inlined
Dump after function inlining, to @file{@var{file}.inlined}.
+
+@item gimple
+@opindex fdump-tree-gimple
+Dump each function before and after the gimplification pass to a file. The
+file name is made by appending @file{.gimple} to the source file name.
+
+@item cfg
+@opindex fdump-tree-cfg
+Dump the control flow graph of each function to a file. The file name is
+made by appending @file{.cfg} to the source file name.
+
+@item vcg
+@opindex fdump-tree-vcg
+Dump the control flow graph of each function to a file in VCG format. The
+file name is made by appending @file{.vcg} to the source file name. Note
+that if the file contains more than one function, the generated file cannot
+be used directly by VCG. You will need to cut and paste each function's
+graph into its own separate file first.
+
+@item ch
+@opindex fdump-tree-ch
+Dump each function after copying loop headers. The file name is made by
+appending @file{.ch} to the source file name.
+
+@item ssa
+@opindex fdump-tree-ssa
+Dump SSA related information to a file. The file name is made by appending
+@file{.ssa} to the source file name.
+
+@item alias
+@opindex fdump-tree-alias
+Dump aliasing information for each function. The file name is made by
+appending @file{.alias} to the source file name.
+
+@item ccp
+@opindex fdump-tree-ccp
+Dump each function after CCP. The file name is made by appending
+@file{.ccp} to the source file name.
+
+@item pre
+@opindex fdump-tree-pre
+Dump trees after partial redundancy elimination. The file name is made
+by appending @file{.pre} to the source file name.
+
+@item dce
+@opindex fdump-tree-dce
+Dump each function after dead code elimination. The file name is made by
+appending @file{.dce} to the source file name.
+
+@item mudflap
+@opindex fdump-tree-mudflap
+Dump each function after adding mudflap instrumentation. The file name is
+made by appending @file{.mudflap} to the source file name.
+
+@item sra
+@opindex fdump-tree-sra
+Dump each function after performing scalar replacement of aggregates. The
+file name is made by appending @file{.sra} to the source file name.
+
+@item dom
+@opindex fdump-tree-dom
+Dump each function after applying dominator tree optimizations. The file
+name is made by appending @file{.dom} to the source file name.
+
+@item dse
+@opindex fdump-tree-dse
+Dump each function after applying dead store elimination. The file
+name is made by appending @file{.dse} to the source file name.
+
+@item phiopt
+@opindex fdump-tree-phiopt
+Dump each function after optimizing PHI nodes into straightline code. The file
+name is made by appending @file{.phiopt} to the source file name.
+
+@item forwprop
+@opindex fdump-tree-forwprop
+Dump each function after forward propagating single use variables. The file
+name is made by appending @file{.forwprop} to the source file name.
+
+@item copyrename
+@opindex fdump-tree-copyrename
+Dump each function after applying the copy rename optimization. The file
+name is made by appending @file{.copyrename} to the source file name.
+
+@item nrv
+@opindex fdump-tree-nrv
+Dump each function after applying the named return value optimization on
+generic trees. The file name is made by appending @file{.nrv} to the source
+file name.
+
+@item all
+@opindex fdump-tree-all
+Enable all the available tree dumps with the flags provided in this option.
@end table
@item -frandom-seed=@var{string}
The default is @option{-fzero-initialized-in-bss}.
+@item -fbounds-check
+@opindex fbounds-check
+For front-ends that support it, generate additional code to check that
+indices used to access arrays are within the declared range. This is
+currently only supported by the Java and Fortran front-ends, where
+this option defaults to true and false respectively.
+
+@item -fmudflap -fmudflapth -fmudflapir
+@opindex fmudflap
+@opindex fmudflapth
+@opindex fmudflapir
+@cindex bounds checking
+@cindex mudflap
+For front-ends that support it (C and C++), instrument all risky
+pointer/array dereferencing operations, some standard library
+string/heap functions, and some other associated constructs with
+range/validity tests. Modules so instrumented should be immune to
+buffer overflows, invalid heap use, and some other classes of C/C++
+programming errors. The instrumentation relies on a separate runtime
+library (@file{libmudflap}), which will be linked into a program if
+@option{-fmudflap} is given at link time. Run-time behavior of the
+instrumented program is controlled by the @env{MUDFLAP_OPTIONS}
+environment variable. See @code{env MUDFLAP_OPTIONS=-help a.out}
+for its options.
+
+Use @option{-fmudflapth} instead of @option{-fmudflap} to compile and to
+link if your program is multi-threaded. Use @option{-fmudflapir}, in
+addition to @option{-fmudflap} or @option{-fmudflapth}, if
+instrumentation should ignore pointer reads. This produces less
+instrumentation (and therefore faster execution) and still provides
+some protection against outright memory corrupting writes, but allows
+erroneously read data to propagate within a program.
+
@item -fstrength-reduce
@opindex fstrength-reduce
Perform the optimizations of loop strength reduction and
Enabled at levels @option{-O2}, @option{-O3}, @option{-Os}.
+@item -ftree-pre
+Perform Partial Redundancy Elimination (PRE) on trees. This flag is
+enabled by default at -O and higher.
+
+@item -ftree-ccp
+Perform sparse conditional constant propagation (CCP) on trees. This flag
+is enabled by default at -O and higher.
+
+@item -ftree-dce
+Perform dead code elimination (DCE) on trees. This flag is enabled by
+default at -O and higher.
+
+@item -ftree-dominator-opts
+Perform dead code elimination (DCE) on trees. This flag is enabled by
+default at -O and higher.
+
+@item -ftree-ch
+Perform loop header copying on trees. This is beneficial since it increases
+effectivity of code motion optimizations. It also saves one jump. This flag
+is enabled by default at -O and higher. It is not enabled for -Os, since it
+usually increases code size.
+
+@item -ftree-sra
+Perform scalar replacement of aggregates. This pass replaces structure
+references with scalars to prevent committing structures to memory too
+early. This flag is enabled by default at -O and higher.
+
+@item -ftree-copyrename
+Perform copy renaming on trees. This pass attempts to rename compiler
+temporaries to other variables at copy locations, usually resulting in
+variable names which more closely resemble the original variables. This flag
+is enabled by default at -O and higher.
+
+@item -ftree-ter
+Perform temporary expression replacement during the SSA->normal phase. Single
+use/single def temporaries are replaced at their use location with their
+defining expression. This results in non-GIMPLE code, but gives the expanders
+much more complex trees to work on resulting in better RTL generation. This is
+enabled by default at -O and higher.
+
+@item -ftree-lrs
+Perform live range splitting during the SSA->normal phase. Distinct live
+ranges of a variable are split into unique variables, allowing for better
+optimization later. This is enabled by default at -O and higher.
+
+@item -ftracer
+@opindex ftracer
+Perform tail duplication to enlarge superblock size. This transformation
+simplifies the control flow of the function allowing other optimizations to do
+better job.
+
+@item -funroll-loops
+@opindex funroll-loops
+Unroll loops whose number of iterations can be determined at compile
+time or upon entry to the loop. @option{-funroll-loops} implies both
+@option{-fstrength-reduce} and @option{-frerun-cse-after-loop}. This
+option makes code larger, and may or may not make it run faster.
+
+@item -funroll-all-loops
+@opindex funroll-all-loops
+Unroll all loops, even if their number of iterations is uncertain when
+the loop is entered. This usually makes programs run more slowly.
+@option{-funroll-all-loops} implies the same options as
+@option{-funroll-loops},
+
+@item -fprefetch-loop-arrays
+@opindex fprefetch-loop-arrays
+If supported by the target machine, generate instructions to prefetch
+memory to improve the performance of loops that access large arrays.
+
@item -fmove-all-movables
@opindex fmove-all-movables
Forces all invariant computations in loops to be moved
This parameter is ignored when @option{-funit-at-a-time} is not used.
The default value is 150.
+@item max-inline-insns-recursive
+@itemx max-inline-insns-recursive-auto
+Specifies maximum number of instructions out-of-line copy of self recursive inline
+function can grow into by performing recursive inlining.
+
+For functions declared inline @option{--param max-inline-insns-recursive} is
+taken into acount. For function not declared inline, recursive inlining
+happens only when @option{-finline-functions} (included in @option{-O3}) is
+enabled and @option{--param max-inline-insns-recursive-auto} is used. The
+default value is 500.
+
+@item max-inline-recursive-depth
+@itemx max-inline-recursive-depth-auto
+Specifies maximum recursion depth used by the recursive inlining.
+
+For functions declared inline @option{--param max-inline-recursive-depth} is
+taken into acount. For function not declared inline, recursive inlining
+happens only when @option{-finline-functions} (included in @option{-O3}) is
+enabled and @option{--param max-inline-recursive-depth-auto} is used. The
+default value is 500.
+
@item max-inline-insns-rtl
For languages that use the RTL inliner (this happens at a later stage
than tree inlining), you can set the maximum allowable size (counted
Maximum number of basic blocks on path that cse considers. The default is 10.
+@item global-var-threshold
+
+Counts the number of function calls (N) and the number of
+call-clobbered variables (V). If NxV is larger than this limit, a
+single artificial variable will be created to represent all the
+call-clobbered variables at function call sites. This artificial
+variable will then be made to alias every call-clobbered variable.
+(done as int * size_t on the host machine; beware overflow).
+
+@item max-aliased-vops
+
+Maxiumum number of virtual operands allowed to represent aliases
+before triggering the alias grouping heuristic. Alias grouping
+reduces compile times and memory consumption needed for aliasing at
+the expense of precision loss in alias information.
+
@item ggc-min-expand
GCC uses a garbage collector to manage its own memory allocation. This
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