mirror of
git://gcc.gnu.org/git/gcc.git
synced 2025-04-15 22:21:20 +08:00
invoke.texi: Clean up "n-bit/byte/word" modifiers.
2012-02-15 Sandra Loosemore <sandra@codesourcery.com> gcc/ * doc/invoke.texi: Clean up "n-bit/byte/word" modifiers. From-SVN: r184291
This commit is contained in:
Sandra Loosemore
Sandra Loosemore
parent
ca59d219fe
commit
e3a66c3884
@ -1,3 +1,7 @@
|
||||
2012-02-15 Sandra Loosemore <sandra@codesourcery.com>
|
||||
|
||||
* doc/invoke.texi: Clean up "n-bit/byte/word" modifiers.
|
||||
|
||||
2012-02-15 Michael Meissner <meissner@linux.vnet.ibm.com>
|
||||
|
||||
PR target/52199
|
||||
|
||||
@ -10440,7 +10440,7 @@ for direct calls. The default is @option{-mlong-calls}.
|
||||
|
||||
@item -msmall16
|
||||
@opindex msmall16
|
||||
Assume addresses can be loaded as 16 bit unsigned values. This does not
|
||||
Assume addresses can be loaded as 16-bit unsigned values. This does not
|
||||
apply to function addresses for which @option{-mlong-calls} semantics
|
||||
are in effect.
|
||||
|
||||
@ -10487,8 +10487,8 @@ The default is @option{-mfp-mode=caller}
|
||||
@opindex mno-postinc
|
||||
@item -mno-postmodify
|
||||
@opindex mno-postmodify
|
||||
Code generation tweaks that disable, respectively, splitting of 32
|
||||
bit loads, generation of post-increment addresses, and generation of
|
||||
Code generation tweaks that disable, respectively, splitting of 32-bit
|
||||
loads, generation of post-increment addresses, and generation of
|
||||
post-modify addresses. The defaults are @option{msplit-lohi},
|
||||
@option{-mpost-inc}, and @option{-mpost-modify}.
|
||||
|
||||
@ -10903,7 +10903,7 @@ this option and always use the original scheme.
|
||||
|
||||
@item -mword-relocations
|
||||
@opindex mword-relocations
|
||||
Only generate absolute relocations on word sized values (i.e. R_ARM_ABS32).
|
||||
Only generate absolute relocations on word-sized values (i.e. R_ARM_ABS32).
|
||||
This is enabled by default on targets (uClinux, SymbianOS) where the runtime
|
||||
loader imposes this restriction, and when @option{-fpic} or @option{-fPIC}
|
||||
is specified.
|
||||
@ -11021,7 +11021,7 @@ subroutines. Code size will be smaller.
|
||||
|
||||
@item -mint8
|
||||
@opindex mint8
|
||||
Assume int to be 8 bit integer. This affects the sizes of all types: A
|
||||
Assume int to be 8-bit integer. This affects the sizes of all types: a
|
||||
char will be 1 byte, an int will be 1 byte, a long will be 2 bytes
|
||||
and long long will be 4 bytes. Please note that this option does not
|
||||
comply to the C standards, but it will provide you with smaller code
|
||||
@ -11251,7 +11251,7 @@ with up to 128@tie{}KiB of program memory.
|
||||
|
||||
@item __AVR_HAVE_8BIT_SP__
|
||||
@item __AVR_HAVE_16BIT_SP__
|
||||
The stack pointer (SP) is 8@tie{}bits resp. 16@tie{}bits wide.
|
||||
The stack pointer (SP) is respectively 8 or 16 bits wide.
|
||||
The definition of these macros is affected by @code{-mtiny-stack}.
|
||||
|
||||
@item __NO_INTERRUPTS__
|
||||
@ -11410,7 +11410,7 @@ This is the default.
|
||||
Tells the compiler to perform function calls by first loading the
|
||||
address of the function into a register and then performing a subroutine
|
||||
call on this register. This switch is needed if the target function
|
||||
will lie outside of the 24 bit addressing range of the offset based
|
||||
lies outside of the 24-bit addressing range of the offset-based
|
||||
version of subroutine call instruction.
|
||||
|
||||
This feature is not enabled by default. Specifying
|
||||
@ -12312,7 +12312,7 @@ routine for the debugger.
|
||||
|
||||
@item -mmalloc64
|
||||
@opindex mmalloc64
|
||||
Default to 64bit memory allocation routines.
|
||||
Default to 64-bit memory allocation routines.
|
||||
@end table
|
||||
|
||||
@node FR30 Options
|
||||
@ -12730,9 +12730,9 @@ Make @code{int} data 32 bits by default.
|
||||
@item -malign-300
|
||||
@opindex malign-300
|
||||
On the H8/300H and H8S, use the same alignment rules as for the H8/300.
|
||||
The default for the H8/300H and H8S is to align longs and floats on 4
|
||||
byte boundaries.
|
||||
@option{-malign-300} causes them to be aligned on 2 byte boundaries.
|
||||
The default for the H8/300H and H8S is to align longs and floats on
|
||||
4-byte boundaries.
|
||||
@option{-malign-300} causes them to be aligned on 2-byte boundaries.
|
||||
This option has no effect on the H8/300.
|
||||
@end table
|
||||
|
||||
@ -12869,7 +12869,7 @@ are passed to that ld. The ld that is called is determined by the
|
||||
@option{--with-ld} configure option, GCC's program search path, and
|
||||
finally by the user's @env{PATH}. The linker used by GCC can be printed
|
||||
using @samp{which `gcc -print-prog-name=ld`}. This option is only available
|
||||
on the 64 bit HP-UX GCC, i.e.@: configured with @samp{hppa*64*-*-hpux*}.
|
||||
on the 64-bit HP-UX GCC, i.e.@: configured with @samp{hppa*64*-*-hpux*}.
|
||||
|
||||
@item -mhp-ld
|
||||
@opindex mhp-ld
|
||||
@ -12881,7 +12881,7 @@ which ld is called, it only changes what parameters are passed to that
|
||||
ld. The ld that is called is determined by the @option{--with-ld}
|
||||
configure option, GCC's program search path, and finally by the user's
|
||||
@env{PATH}. The linker used by GCC can be printed using @samp{which
|
||||
`gcc -print-prog-name=ld`}. This option is only available on the 64 bit
|
||||
`gcc -print-prog-name=ld`}. This option is only available on the 64-bit
|
||||
HP-UX GCC, i.e.@: configured with @samp{hppa*64*-*-hpux*}.
|
||||
|
||||
@item -mlong-calls
|
||||
@ -13140,7 +13140,7 @@ effective. For the x86-64 compiler, these extensions are enabled by default.
|
||||
|
||||
The resulting code should be considerably faster in the majority of cases and avoid
|
||||
the numerical instability problems of 387 code, but may break some existing
|
||||
code that expects temporaries to be 80bit.
|
||||
code that expects temporaries to be 80 bits.
|
||||
|
||||
This is the default choice for the x86-64 compiler.
|
||||
|
||||
@ -13209,9 +13209,9 @@ instructions are not generated unless you also use the
|
||||
@opindex malign-double
|
||||
@opindex mno-align-double
|
||||
Control whether GCC aligns @code{double}, @code{long double}, and
|
||||
@code{long long} variables on a two word boundary or a one word
|
||||
boundary. Aligning @code{double} variables on a two word boundary will
|
||||
produce code that runs somewhat faster on a @samp{Pentium} at the
|
||||
@code{long long} variables on a two-word boundary or a one-word
|
||||
boundary. Aligning @code{double} variables on a two-word boundary
|
||||
produces code that runs somewhat faster on a @samp{Pentium} at the
|
||||
expense of more memory.
|
||||
|
||||
On x86-64, @option{-malign-double} is enabled by default.
|
||||
@ -13228,17 +13228,17 @@ without that switch.
|
||||
@opindex m128bit-long-double
|
||||
These switches control the size of @code{long double} type. The i386
|
||||
application binary interface specifies the size to be 96 bits,
|
||||
so @option{-m96bit-long-double} is the default in 32 bit mode.
|
||||
so @option{-m96bit-long-double} is the default in 32-bit mode.
|
||||
|
||||
Modern architectures (Pentium and newer) would prefer @code{long double}
|
||||
to be aligned to an 8 or 16 byte boundary. In arrays or structures
|
||||
conforming to the ABI, this would not be possible. So specifying a
|
||||
@option{-m128bit-long-double} will align @code{long double}
|
||||
to a 16 byte boundary by padding the @code{long double} with an additional
|
||||
32 bit zero.
|
||||
Modern architectures (Pentium and newer) prefer @code{long double}
|
||||
to be aligned to an 8- or 16-byte boundary. In arrays or structures
|
||||
conforming to the ABI, this is not possible. So specifying
|
||||
@option{-m128bit-long-double} aligns @code{long double}
|
||||
to a 16-byte boundary by padding the @code{long double} with an additional
|
||||
32-bit zero.
|
||||
|
||||
In the x86-64 compiler, @option{-m128bit-long-double} is the default choice as
|
||||
its ABI specifies that @code{long double} is to be aligned on 16 byte boundary.
|
||||
its ABI specifies that @code{long double} is to be aligned on 16-byte boundary.
|
||||
|
||||
Notice that neither of these options enable any extra precision over the x87
|
||||
standard of 80 bits for a @code{long double}.
|
||||
@ -13361,10 +13361,10 @@ boundary. If @option{-mincoming-stack-boundary} is not specified,
|
||||
the one specified by @option{-mpreferred-stack-boundary} will be used.
|
||||
|
||||
On Pentium and PentiumPro, @code{double} and @code{long double} values
|
||||
should be aligned to an 8 byte boundary (see @option{-malign-double}) or
|
||||
should be aligned to an 8-byte boundary (see @option{-malign-double}) or
|
||||
suffer significant run time performance penalties. On Pentium III, the
|
||||
Streaming SIMD Extension (SSE) data type @code{__m128} may not work
|
||||
properly if it is not 16 byte aligned.
|
||||
properly if it is not 16-byte aligned.
|
||||
|
||||
To ensure proper alignment of this values on the stack, the stack boundary
|
||||
must be as aligned as that required by any value stored on the stack.
|
||||
@ -13625,8 +13625,9 @@ but GCC doesn't know about it.
|
||||
|
||||
@item -minline-all-stringops
|
||||
@opindex minline-all-stringops
|
||||
By default GCC inlines string operations only when destination is known to be
|
||||
aligned at least to 4 byte boundary. This enables more inlining, increase code
|
||||
By default GCC inlines string operations only when the destination is
|
||||
known to be aligned to least a 4-byte boundary.
|
||||
This enables more inlining, increase code
|
||||
size, but may improve performance of code that depends on fast memcpy, strlen
|
||||
and memset for short lengths.
|
||||
|
||||
@ -14118,7 +14119,7 @@ routine for the debugger.
|
||||
|
||||
@item -mmalloc64
|
||||
@opindex mmalloc64
|
||||
Default to 64bit memory allocation routines.
|
||||
Default to 64-bit memory allocation routines.
|
||||
@end table
|
||||
|
||||
@node LM32 Options
|
||||
@ -14727,7 +14728,7 @@ Always treat bit-fields as int-sized.
|
||||
@itemx -mno-4byte-functions
|
||||
@opindex m4byte-functions
|
||||
@opindex mno-4byte-functions
|
||||
Force all functions to be aligned to a four byte boundary.
|
||||
Force all functions to be aligned to a 4-byte boundary.
|
||||
|
||||
@item -mcallgraph-data
|
||||
@itemx -mno-callgraph-data
|
||||
@ -14795,7 +14796,7 @@ registers.
|
||||
@opindex mbased=
|
||||
Variables of size @var{n} bytes or smaller will be placed in the
|
||||
@code{.based} section by default. Based variables use the @code{$tp}
|
||||
register as a base register, and there is a 128 byte limit to the
|
||||
register as a base register, and there is a 128-byte limit to the
|
||||
@code{.based} section.
|
||||
|
||||
@item -mbitops
|
||||
@ -14895,7 +14896,7 @@ low-overhead looping.
|
||||
@item -ms
|
||||
@opindex ms
|
||||
Causes all variables to default to the @code{.tiny} section. Note
|
||||
that there is a 65536 byte limit to this section. Accesses to these
|
||||
that there is a 65536-byte limit to this section. Accesses to these
|
||||
variables use the @code{%gp} base register.
|
||||
|
||||
@item -msatur
|
||||
@ -14927,7 +14928,7 @@ this option, functions default to the @code{.near} section.
|
||||
Variables that are @var{n} bytes or smaller will be allocated to the
|
||||
@code{.tiny} section. These variables use the @code{$gp} base
|
||||
register. The default for this option is 4, but note that there's a
|
||||
65536 byte limit to the @code{.tiny} section.
|
||||
65536-byte limit to the @code{.tiny} section.
|
||||
|
||||
@end table
|
||||
|
||||
@ -16748,9 +16749,9 @@ and unions that contain bit-fields to be aligned to the base type of the
|
||||
bit-field.
|
||||
|
||||
For example, by default a structure containing nothing but 8
|
||||
@code{unsigned} bit-fields of length 1 would be aligned to a 4 byte
|
||||
boundary and have a size of 4 bytes. By using @option{-mno-bit-align},
|
||||
the structure would be aligned to a 1 byte boundary and be one byte in
|
||||
@code{unsigned} bit-fields of length 1 is aligned to a 4-byte
|
||||
boundary and has a size of 4 bytes. By using @option{-mno-bit-align},
|
||||
the structure is aligned to a 1-byte boundary and is 1 byte in
|
||||
size.
|
||||
|
||||
@item -mno-strict-align
|
||||
@ -16771,7 +16772,7 @@ PowerPC system loader should relocate the entire contents of
|
||||
a table of 32-bit addresses generated by this option. For this to
|
||||
work, all objects linked together must be compiled with
|
||||
@option{-mrelocatable} or @option{-mrelocatable-lib}.
|
||||
@option{-mrelocatable} code aligns the stack to an 8 byte boundary.
|
||||
@option{-mrelocatable} code aligns the stack to an 8-byte boundary.
|
||||
|
||||
@item -mrelocatable-lib
|
||||
@itemx -mno-relocatable-lib
|
||||
@ -16987,11 +16988,11 @@ header to indicate that @samp{eabi} extended relocations are used.
|
||||
On System V.4 and embedded PowerPC systems do (do not) adhere to the
|
||||
Embedded Applications Binary Interface (eabi) which is a set of
|
||||
modifications to the System V.4 specifications. Selecting @option{-meabi}
|
||||
means that the stack is aligned to an 8 byte boundary, a function
|
||||
means that the stack is aligned to an 8-byte boundary, a function
|
||||
@code{__eabi} is called to from @code{main} to set up the eabi
|
||||
environment, and the @option{-msdata} option can use both @code{r2} and
|
||||
@code{r13} to point to two separate small data areas. Selecting
|
||||
@option{-mno-eabi} means that the stack is aligned to a 16 byte boundary,
|
||||
@option{-mno-eabi} means that the stack is aligned to a 16-byte boundary,
|
||||
do not call an initialization function from @code{main}, and the
|
||||
@option{-msdata} option will only use @code{r13} to point to a single
|
||||
small data area. The @option{-meabi} option is on by default if you
|
||||
@ -17201,7 +17202,7 @@ the floating-point number is too large to fit in an integer.
|
||||
@opindex mpointers-to-nested-functions
|
||||
Generate (do not generate) code to load up the static chain register
|
||||
(@var{r11}) when calling through a pointer on AIX and 64-bit Linux
|
||||
systems where a function pointer points to a 3 word descriptor giving
|
||||
systems where a function pointer points to a 3-word descriptor giving
|
||||
the function address, TOC value to be loaded in register @var{r2}, and
|
||||
static chain value to be loaded in register @var{r11}. The
|
||||
@option{-mpointers-to-nested-functions} is on by default. You will
|
||||
@ -17425,7 +17426,7 @@ instructions. This is the default for @option{-march=z9-ec} or higher.
|
||||
@opindex mlong-double-64
|
||||
@opindex mlong-double-128
|
||||
These switches control the size of @code{long double} type. A size
|
||||
of 64bit makes the @code{long double} type equivalent to the @code{double}
|
||||
of 64 bits makes the @code{long double} type equivalent to the @code{double}
|
||||
type. This is the default.
|
||||
|
||||
@item -mbackchain
|
||||
@ -17779,7 +17780,7 @@ Mark the @code{MAC} register as call-clobbered, even if
|
||||
@opindex mieee
|
||||
Increase IEEE compliance of floating-point code.
|
||||
At the moment, this is equivalent to @option{-fno-finite-math-only}.
|
||||
When generating 16 bit SH opcodes, getting IEEE-conforming results for
|
||||
When generating 16-bit SH opcodes, getting IEEE-conforming results for
|
||||
comparisons of NANs / infinities incurs extra overhead in every
|
||||
floating-point comparison, therefore the default is set to
|
||||
@option{-ffinite-math-only}.
|
||||
@ -17878,7 +17879,7 @@ needed for unwinding to avoid changing the stack frame around conditional code.
|
||||
|
||||
@item -mdivsi3_libfunc=@var{name}
|
||||
@opindex mdivsi3_libfunc=@var{name}
|
||||
Set the name of the library function used for 32 bit signed division to
|
||||
Set the name of the library function used for 32-bit signed division to
|
||||
@var{name}. This only affect the name used in the call and inv:call
|
||||
division strategies, and the compiler will still expect the same
|
||||
sets of input/output/clobbered registers as if this option was not present.
|
||||
@ -17900,12 +17901,12 @@ TARGET_ADJUST_UNROLL_MAX target hook.
|
||||
@item -mindexed-addressing
|
||||
@opindex mindexed-addressing
|
||||
Enable the use of the indexed addressing mode for SHmedia32/SHcompact.
|
||||
This is only safe if the hardware and/or OS implement 32 bit wrap-around
|
||||
This is only safe if the hardware and/or OS implement 32-bit wrap-around
|
||||
semantics for the indexed addressing mode. The architecture allows the
|
||||
implementation of processors with 64 bit MMU, which the OS could use to
|
||||
get 32 bit addressing, but since no current hardware implementation supports
|
||||
implementation of processors with 64-bit MMU, which the OS could use to
|
||||
get 32-bit addressing, but since no current hardware implementation supports
|
||||
this or any other way to make the indexed addressing mode safe to use in
|
||||
the 32 bit ABI, the default is -mno-indexed-addressing.
|
||||
the 32-bit ABI, the default is @option{-mno-indexed-addressing}.
|
||||
|
||||
@item -mgettrcost=@var{number}
|
||||
@opindex mgettrcost=@var{number}
|
||||
@ -18059,11 +18060,11 @@ this is much slower than calling the ABI library routines. Thus the
|
||||
@itemx -munaligned-doubles
|
||||
@opindex mno-unaligned-doubles
|
||||
@opindex munaligned-doubles
|
||||
Assume that doubles have 8 byte alignment. This is the default.
|
||||
Assume that doubles have 8-byte alignment. This is the default.
|
||||
|
||||
With @option{-munaligned-doubles}, GCC assumes that doubles have 8 byte
|
||||
With @option{-munaligned-doubles}, GCC assumes that doubles have 8-byte
|
||||
alignment only if they are contained in another type, or if they have an
|
||||
absolute address. Otherwise, it assumes they have 4 byte alignment.
|
||||
absolute address. Otherwise, it assumes they have 4-byte alignment.
|
||||
Specifying this option avoids some rare compatibility problems with code
|
||||
generated by other compilers. It is not the default because it results
|
||||
in a performance loss, especially for floating-point code.
|
||||
@ -18073,7 +18074,7 @@ in a performance loss, especially for floating-point code.
|
||||
@opindex mno-faster-structs
|
||||
@opindex mfaster-structs
|
||||
With @option{-mfaster-structs}, the compiler assumes that structures
|
||||
should have 8 byte alignment. This enables the use of pairs of
|
||||
should have 8-byte alignment. This enables the use of pairs of
|
||||
@code{ldd} and @code{std} instructions for copies in structure
|
||||
assignment, in place of twice as many @code{ld} and @code{st} pairs.
|
||||
However, the use of this changed alignment directly violates the SPARC
|
||||
@ -18181,7 +18182,7 @@ native Solaris and GNU/Linux toolchains, @samp{native} can also be used.
|
||||
@opindex mno-v8plus
|
||||
With @option{-mv8plus}, GCC generates code for the SPARC-V8+ ABI@. The
|
||||
difference from the V8 ABI is that the global and out registers are
|
||||
considered 64-bit wide. This is enabled by default on Solaris in 32-bit
|
||||
considered 64 bits wide. This is enabled by default on Solaris in 32-bit
|
||||
mode for all SPARC-V9 processors.
|
||||
|
||||
@item -mvis
|
||||
@ -18364,7 +18365,7 @@ or to make an object a little bit smaller.
|
||||
|
||||
By default, GCC generates code assuming that addresses are never larger
|
||||
than 18 bits. With @option{-mlarge-mem} code is generated that assumes
|
||||
a full 32 bit address.
|
||||
a full 32-bit address.
|
||||
|
||||
@item -mstdmain
|
||||
@opindex mstdmain
|
||||
@ -19388,8 +19389,8 @@ field's type, aligned to a natural alignment if possible. For
|
||||
example, targets with memory-mapped peripheral registers might require
|
||||
all such accesses to be 16 bits wide; with this flag the user could
|
||||
declare all peripheral bitfields as ``unsigned short'' (assuming short
|
||||
is 16 bits on these targets) to force GCC to use 16 bit accesses
|
||||
instead of, perhaps, a more efficient 32 bit access.
|
||||
is 16 bits on these targets) to force GCC to use 16-bit accesses
|
||||
instead of, perhaps, a more efficient 32-bit access.
|
||||
|
||||
If this option is disabled, the compiler will use the most efficient
|
||||
instruction. In the previous example, that might be a 32-bit load
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user