@c Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
-@c 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
+@c 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
@c Free Software Foundation, Inc.
@c This is part of the GCC manual.
@c For copying conditions, see the file gcc.texi.
@c man begin COPYRIGHT
Copyright @copyright{} 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
-1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
-2007 Free Software Foundation, Inc.
+1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
+Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.2 or
-Werror -Werror=* @gol
-Wfatal-errors -Wfloat-equal -Wformat -Wformat=2 @gol
-Wno-format-extra-args -Wformat-nonliteral @gol
--Wformat-security -Wformat-y2k @gol
+-Wformat-security -Wformat-y2k -Wignored-qualifiers @gol
-Wimplicit -Wimplicit-function-declaration -Wimplicit-int @gol
-Wimport -Wno-import -Winit-self -Winline @gol
-Wno-int-to-pointer-cast -Wno-invalid-offsetof @gol
-ftest-coverage -ftime-report -fvar-tracking @gol
-g -g@var{level} -gcoff -gdwarf-2 @gol
-ggdb -gstabs -gstabs+ -gvms -gxcoff -gxcoff+ @gol
--fdebug-prefix-map=@var{old}=@var{new} @gol
+-fno-merge-debug-strings -fdebug-prefix-map=@var{old}=@var{new} @gol
-femit-struct-debug-baseonly -femit-struct-debug-reduced @gol
-femit-struct-debug-detailed@r{[}=@var{spec-list}@r{]} @gol
-p -pg -print-file-name=@var{library} -print-libgcc-file-name @gol
@emph{System V Options}
@gccoptlist{-Qy -Qn -YP,@var{paths} -Ym,@var{dir}}
-@emph{TMS320C3x/C4x Options}
-@gccoptlist{-mcpu=@var{cpu} -mbig -msmall -mregparm -mmemparm @gol
--mfast-fix -mmpyi -mbk -mti -mdp-isr-reload @gol
--mrpts=@var{count} -mrptb -mdb -mloop-unsigned @gol
--mparallel-insns -mparallel-mpy -mpreserve-float}
-
@emph{V850 Options}
@gccoptlist{-mlong-calls -mno-long-calls -mep -mno-ep @gol
-mprolog-function -mno-prolog-function -mspace @gol
Enable handling of OpenMP directives @code{#pragma omp} in C/C++ and
@code{!$omp} in Fortran. When @option{-fopenmp} is specified, the
compiler generates parallel code according to the OpenMP Application
-Program Interface v2.5 @w{@uref{http://www.openmp.org/}}.
+Program Interface v2.5 @w{@uref{http://www.openmp.org/}}. This option
+implies @option{-pthread}, and thus is only supported on targets that
+have support for @option{-pthread}.
@item -fms-extensions
@opindex fms-extensions
-Wsequence-point @gol
-Wsign-compare @r{(only in C++)} @gol
-Wstrict-aliasing @gol
--Wstrict-overflow @gol
+-Wstrict-overflow=1 @gol
-Wswitch @gol
-Wtrigraphs @gol
-Wuninitialized @r{(only with} @option{-O1} @r{and above)} @gol
@gccoptlist{-Wclobbered @gol
-Wempty-body @gol
+-Wignored-qualifiers @gol
-Wmissing-field-initializers @gol
-Wmissing-parameter-type @r{(C only)} @gol
-Wold-style-declaration @r{(C only)} @gol
Same as @option{-Wimplicit-int} and @option{-Wimplicit-function-declaration}.
This warning is enabled by @option{-Wall}.
+@item -Wignored-qualifiers
+@opindex Wignored-qualifiers
+@opindex Wno-ignored-qualifiers
+Warn if the return type of a function has a type qualifier
+such as @code{const}. For ISO C such a type qualifier has no effect,
+since the value returned by a function is not an lvalue.
+For C++, the warning is only emitted for scalar types or @code{void}.
+ISO C prohibits qualified @code{void} return types on function
+definitions, so such return types always receive a warning
+even without this option.
+
+This warning is also enabled by @option{-Wextra}.
+
@item -Wmain
@opindex Wmain
Warn if the type of @samp{main} is suspicious. @samp{main} should be a
without a value), and about a @code{return} statement with a
expression in a function whose return-type is @code{void}.
-Also warn if the return type of a function has a type qualifier
-such as @code{const}. For ISO C such a type qualifier has no effect,
-since the value returned by a function is not an lvalue.
-For C++, the warning is only emitted for scalar types or @code{void}.
-ISO C prohibits qualified @code{void} return types on function
-definitions, so such return types always receive a warning
-even without this option.
-
For C++, a function without return type always produces a diagnostic
message, even when @option{-Wno-return-type} is specified. The only
exceptions are @samp{main} and functions defined in system headers.
Does not warn about incomplete types.
@item -Wstrict-overflow
-@item -Wstrict-overflow=@var{n}
+@itemx -Wstrict-overflow=@var{n}
@opindex Wstrict-overflow
This option is only active when @option{-fstrict-overflow} is active.
It warns about cases where the compiler optimizes based on the
This option works only with DWARF 2.
+@item -fno-merge-debug-strings
+@opindex fmerge-debug-strings
+@opindex fno-merge-debug-strings
+Direct the linker to merge together strings which are identical in
+different object files. This is not supported by all assemblers or
+linker. This decreases the size of the debug information in the
+output file at the cost of increasing link processing time. This is
+on by default.
+
@item -fdebug-prefix-map=@var{old}=@var{new}
@opindex fdebug-prefix-map
When compiling files in directory @file{@var{old}}, record debugging
This is only possible for loops whose iterations are independent
and can be arbitrarily reordered. The optimization is only
profitable on multiprocessor machines, for loops that are CPU-intensive,
-rather than constrained e.g. by memory bandwidth.
+rather than constrained e.g. by memory bandwidth. This option
+implies @option{-pthread}, and thus is only supported on targets
+that have support for @option{-pthread}.
@item -ftree-sra
@opindex ftree-sra
Enabled at levels @option{-O}, @option{-O2}, @option{-O3}, @option{-Os}.
@item -fno-toplevel-reorder
+@opindex fno-toplevel-reorder
Do not reorder top-level functions, variables, and @code{asm}
statements. Output them in the same order that they appear in the
input file. When this option is used, unreferenced static variables
taken into account. 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 450.
+default value is 8.
@item min-inline-recursive-probability
Recursive inlining is profitable only for function having deep recursion
which prevents the runaway behaviour. Setting a value of 0 for
this paramter will allow an unlimited set length.
+@item sccvn-max-scc-size
+Maximum size of a strongly connected component (SCC) during SCCVN
+processing. If this limit is hit, SCCVN processing for the whole
+function will not be done and optimizations depending on it will
+be disabled. The default maximum SCC size is 10000.
+
@end table
@end table
* SPARC Options::
* SPU Options::
* System V Options::
-* TMS320C3x/C4x Options::
* V850 Options::
* VAX Options::
* VxWorks Options::
@item -mcpu=@var{cpu}@r{[}-@var{sirevision}@r{]}
@opindex mcpu=
Specifies the name of the target Blackfin processor. Currently, @var{cpu}
-can be one of @samp{bf522}, @samp{bf525}, @samp{bf527},
+can be one of @samp{bf522}, @samp{bf523}, @samp{bf524},
+@samp{bf525}, @samp{bf526}, @samp{bf527},
@samp{bf531}, @samp{bf532}, @samp{bf533}, @samp{bf534},
@samp{bf536}, @samp{bf537}, @samp{bf538}, @samp{bf539},
-@samp{bf542}, @samp{bf544}, @samp{bf548}, @samp{bf549},
+@samp{bf542}, @samp{bf544}, @samp{bf547}, @samp{bf548}, @samp{bf549},
@samp{bf561}.
The optional @var{sirevision} specifies the silicon revision of the target
Blackfin processor. Any workarounds available for the targeted silicon revision
@item -mrecip
@opindex mrecip
This option will enable GCC to use RCPSS and RSQRTSS instructions (and their
-vectorized variants RCPPS and RSQRTPS) instead of DIVSS and SQRTSS (and their
-vectorized variants). These instructions will be generated only when
-@option{-funsafe-math-optimizations} is enabled.
+vectorized variants RCPPS and RSQRTPS) with an additional Newton-Rhapson step
+to increase precision instead of DIVSS and SQRTSS (and their vectorized
+variants) for single precision floating point arguments. These instructions
+are generated only when @option{-funsafe-math-optimizations} is enabled
+together with @option{-finite-math-only} and @option{-fno-trapping-math}.
+Note that while the throughput of the sequence is higher than the throughput
+of the non-reciprocal instruction, the precision of the sequence can be
+decreased by up to 2 ulp (i.e. the inverse of 1.0 equals 0.99999994).
@item -mveclibabi=@var{type}
@opindex mveclibabi
@c the generic assembler that comes with Solaris takes just -Ym.
@end table
-@node TMS320C3x/C4x Options
-@subsection TMS320C3x/C4x Options
-@cindex TMS320C3x/C4x Options
-
-These @samp{-m} options are defined for TMS320C3x/C4x implementations:
-
-@table @gcctabopt
-
-@item -mcpu=@var{cpu_type}
-@opindex mcpu
-Set the instruction set, register set, and instruction scheduling
-parameters for machine type @var{cpu_type}. Supported values for
-@var{cpu_type} are @samp{c30}, @samp{c31}, @samp{c32}, @samp{c40}, and
-@samp{c44}. The default is @samp{c40} to generate code for the
-TMS320C40.
-
-@item -mbig-memory
-@itemx -mbig
-@itemx -msmall-memory
-@itemx -msmall
-@opindex mbig-memory
-@opindex mbig
-@opindex msmall-memory
-@opindex msmall
-Generates code for the big or small memory model. The small memory
-model assumed that all data fits into one 64K word page. At run-time
-the data page (DP) register must be set to point to the 64K page
-containing the .bss and .data program sections. The big memory model is
-the default and requires reloading of the DP register for every direct
-memory access.
-
-@item -mbk
-@itemx -mno-bk
-@opindex mbk
-@opindex mno-bk
-Allow (disallow) allocation of general integer operands into the block
-count register BK@.
-
-@item -mdb
-@itemx -mno-db
-@opindex mdb
-@opindex mno-db
-Enable (disable) generation of code using decrement and branch,
-DBcond(D), instructions. This is enabled by default for the C4x. To be
-on the safe side, this is disabled for the C3x, since the maximum
-iteration count on the C3x is @math{2^{23} + 1} (but who iterates loops more than
-@math{2^{23}} times on the C3x?). Note that GCC will try to reverse a loop so
-that it can utilize the decrement and branch instruction, but will give
-up if there is more than one memory reference in the loop. Thus a loop
-where the loop counter is decremented can generate slightly more
-efficient code, in cases where the RPTB instruction cannot be utilized.
-
-@item -mdp-isr-reload
-@itemx -mparanoid
-@opindex mdp-isr-reload
-@opindex mparanoid
-Force the DP register to be saved on entry to an interrupt service
-routine (ISR), reloaded to point to the data section, and restored on
-exit from the ISR@. This should not be required unless someone has
-violated the small memory model by modifying the DP register, say within
-an object library.
-
-@item -mmpyi
-@itemx -mno-mpyi
-@opindex mmpyi
-@opindex mno-mpyi
-For the C3x use the 24-bit MPYI instruction for integer multiplies
-instead of a library call to guarantee 32-bit results. Note that if one
-of the operands is a constant, then the multiplication will be performed
-using shifts and adds. If the @option{-mmpyi} option is not specified for the C3x,
-then squaring operations are performed inline instead of a library call.
-
-@item -mfast-fix
-@itemx -mno-fast-fix
-@opindex mfast-fix
-@opindex mno-fast-fix
-The C3x/C4x FIX instruction to convert a floating point value to an
-integer value chooses the nearest integer less than or equal to the
-floating point value rather than to the nearest integer. Thus if the
-floating point number is negative, the result will be incorrectly
-truncated an additional code is necessary to detect and correct this
-case. This option can be used to disable generation of the additional
-code required to correct the result.
-
-@item -mrptb
-@itemx -mno-rptb
-@opindex mrptb
-@opindex mno-rptb
-Enable (disable) generation of repeat block sequences using the RPTB
-instruction for zero overhead looping. The RPTB construct is only used
-for innermost loops that do not call functions or jump across the loop
-boundaries. There is no advantage having nested RPTB loops due to the
-overhead required to save and restore the RC, RS, and RE registers.
-This is enabled by default with @option{-O2}.
-
-@item -mrpts=@var{count}
-@itemx -mno-rpts
-@opindex mrpts
-@opindex mno-rpts
-Enable (disable) the use of the single instruction repeat instruction
-RPTS@. If a repeat block contains a single instruction, and the loop
-count can be guaranteed to be less than the value @var{count}, GCC will
-emit a RPTS instruction instead of a RPTB@. If no value is specified,
-then a RPTS will be emitted even if the loop count cannot be determined
-at compile time. Note that the repeated instruction following RPTS does
-not have to be reloaded from memory each iteration, thus freeing up the
-CPU buses for operands. However, since interrupts are blocked by this
-instruction, it is disabled by default.
-
-@item -mloop-unsigned
-@itemx -mno-loop-unsigned
-@opindex mloop-unsigned
-@opindex mno-loop-unsigned
-The maximum iteration count when using RPTS and RPTB (and DB on the C40)
-is @math{2^{31} + 1} since these instructions test if the iteration count is
-negative to terminate the loop. If the iteration count is unsigned
-there is a possibility than the @math{2^{31} + 1} maximum iteration count may be
-exceeded. This switch allows an unsigned iteration count.
-
-@item -mti
-@opindex mti
-Try to emit an assembler syntax that the TI assembler (asm30) is happy
-with. This also enforces compatibility with the API employed by the TI
-C3x C compiler. For example, long doubles are passed as structures
-rather than in floating point registers.
-
-@item -mregparm
-@itemx -mmemparm
-@opindex mregparm
-@opindex mmemparm
-Generate code that uses registers (stack) for passing arguments to functions.
-By default, arguments are passed in registers where possible rather
-than by pushing arguments on to the stack.
-
-@item -mparallel-insns
-@itemx -mno-parallel-insns
-@opindex mparallel-insns
-@opindex mno-parallel-insns
-Allow the generation of parallel instructions. This is enabled by
-default with @option{-O2}.
-
-@item -mparallel-mpy
-@itemx -mno-parallel-mpy
-@opindex mparallel-mpy
-@opindex mno-parallel-mpy
-Allow the generation of MPY||ADD and MPY||SUB parallel instructions,
-provided @option{-mparallel-insns} is also specified. These instructions have
-tight register constraints which can pessimize the code generation
-of large functions.
-
-@end table
-
@node V850 Options
@subsection V850 Options
@cindex V850 Options
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