gcc.info: Library Calls
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Implicit Calls to Library Routines
Here is an explanation of implicit calls to library routines.
`MULSI3_LIBCALL'
A C string constant giving the name of the function to call for
multiplication of one signed full-word by another. If you do not
define this macro, the default name is used, which is `__mulsi3',
a function defined in `libgcc.a'.
`DIVSI3_LIBCALL'
A C string constant giving the name of the function to call for
division of one signed full-word by another. If you do not define
this macro, the default name is used, which is `__divsi3', a
function defined in `libgcc.a'.
`UDIVSI3_LIBCALL'
A C string constant giving the name of the function to call for
division of one unsigned full-word by another. If you do not
define this macro, the default name is used, which is `__udivsi3',
a function defined in `libgcc.a'.
`MODSI3_LIBCALL'
A C string constant giving the name of the function to call for the
remainder in division of one signed full-word by another. If you
do not define this macro, the default name is used, which is
`__modsi3', a function defined in `libgcc.a'.
`UMODSI3_LIBCALL'
A C string constant giving the name of the function to call for the
remainder in division of one unsigned full-word by another. If
you do not define this macro, the default name is used, which is
`__umodsi3', a function defined in `libgcc.a'.
`MULDI3_LIBCALL'
A C string constant giving the name of the function to call for
multiplication of one signed double-word by another. If you do not
define this macro, the default name is used, which is `__muldi3',
a function defined in `libgcc.a'.
`DIVDI3_LIBCALL'
A C string constant giving the name of the function to call for
division of one signed double-word by another. If you do not
define this macro, the default name is used, which is `__divdi3', a
function defined in `libgcc.a'.
`UDIVDI3_LIBCALL'
A C string constant giving the name of the function to call for
division of one unsigned full-word by another. If you do not
define this macro, the default name is used, which is `__udivdi3',
a function defined in `libgcc.a'.
`MODDI3_LIBCALL'
A C string constant giving the name of the function to call for the
remainder in division of one signed double-word by another. If
you do not define this macro, the default name is used, which is
`__moddi3', a function defined in `libgcc.a'.
`UMODDI3_LIBCALL'
A C string constant giving the name of the function to call for the
remainder in division of one unsigned full-word by another. If
you do not define this macro, the default name is used, which is
`__umoddi3', a function defined in `libgcc.a'.
`INIT_TARGET_OPTABS'
Define this macro as a C statement that declares additional library
routines renames existing ones. `init_optabs' calls this macro
after initializing all the normal library routines.
`TARGET_EDOM'
The value of `EDOM' on the target machine, as a C integer constant
expression. If you don't define this macro, GNU CC does not
attempt to deposit the value of `EDOM' into `errno' directly.
Look in `/usr/include/errno.h' to find the value of `EDOM' on your
system.
If you do not define `TARGET_EDOM', then compiled code reports
domain errors by calling the library function and letting it
report the error. If mathematical functions on your system use
`matherr' when there is an error, then you should leave
`TARGET_EDOM' undefined so that `matherr' is used normally.
`GEN_ERRNO_RTX'
Define this macro as a C expression to create an rtl expression
that refers to the global "variable" `errno'. (On certain systems,
`errno' may not actually be a variable.) If you don't define this
macro, a reasonable default is used.
`TARGET_MEM_FUNCTIONS'
Define this macro if GNU CC should generate calls to the System V
(and ANSI C) library functions `memcpy' and `memset' rather than
the BSD functions `bcopy' and `bzero'.
`LIBGCC_NEEDS_DOUBLE'
Define this macro if only `float' arguments cannot be passed to
library routines (so they must be converted to `double'). This
macro affects both how library calls are generated and how the
library routines in `libgcc1.c' accept their arguments. It is
useful on machines where floating and fixed point arguments are
passed differently, such as the i860.
`FLOAT_ARG_TYPE'
Define this macro to override the type used by the library
routines to pick up arguments of type `float'. (By default, they
use a union of `float' and `int'.)
The obvious choice would be `float'--but that won't work with
traditional C compilers that expect all arguments declared as
`float' to arrive as `double'. To avoid this conversion, the
library routines ask for the value as some other type and then
treat it as a `float'.
On some systems, no other type will work for this. For these
systems, you must use `LIBGCC_NEEDS_DOUBLE' instead, to force
conversion of the values `double' before they are passed.
`FLOATIFY (PASSED-VALUE)'
Define this macro to override the way library routines redesignate
a `float' argument as a `float' instead of the type it was passed
as. The default is an expression which takes the `float' field of
the union.
`FLOAT_VALUE_TYPE'
Define this macro to override the type used by the library
routines to return values that ought to have type `float'. (By
default, they use `int'.)
The obvious choice would be `float'--but that won't work with
traditional C compilers gratuitously convert values declared as
`float' into `double'.
`INTIFY (FLOAT-VALUE)'
Define this macro to override the way the value of a
`float'-returning library routine should be packaged in order to
return it. These functions are actually declared to return type
`FLOAT_VALUE_TYPE' (normally `int').
These values can't be returned as type `float' because traditional
C compilers would gratuitously convert the value to a `double'.
A local variable named `intify' is always available when the macro
`INTIFY' is used. It is a union of a `float' field named `f' and
a field named `i' whose type is `FLOAT_VALUE_TYPE' or `int'.
If you don't define this macro, the default definition works by
copying the value through that union.
`nongcc_SI_type'
Define this macro as the name of the data type corresponding to
`SImode' in the system's own C compiler.
You need not define this macro if that type is `long int', as it
usually is.
`nongcc_word_type'
Define this macro as the name of the data type corresponding to the
word_mode in the system's own C compiler.
You need not define this macro if that type is `long int', as it
usually is.
`perform_...'
Define these macros to supply explicit C statements to carry out
various arithmetic operations on types `float' and `double' in the
library routines in `libgcc1.c'. See that file for a full list of
these macros and their arguments.
On most machines, you don't need to define any of these macros,
because the C compiler that comes with the system takes care of
doing them.
`NEXT_OBJC_RUNTIME'
Define this macro to generate code for Objective C message sending
using the calling convention of the NeXT system. This calling
convention involves passing the object, the selector and the
method arguments all at once to the method-lookup library function.
The default calling convention passes just the object and the
selector to the lookup function, which returns a pointer to the
method.
Created Wed Sep 1 16:42:25 2004 on bee with info_to_html version 0.9.6.