Red Hat ENTERPRISE LINUX 4 Manual page 218

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6.45. Other built-in functions provided by GCC
GCC provides a large number of built-in functions other than the ones mentioned above. Some of
these are for internal use in the processing of exceptions or variable-length argument lists and will not
be documented here because they may change from time to time; we do not recommend general use
of these functions.
The remaining functions are provided for optimization purposes.
GCC includes built-in versions of many of the functions in the standard C library. The versions pre-
fixed with
__builtin_
even if you specify the
these functions are only optimized in certain cases; if they are not optimized in a particular case, a call
to the library function will be emitted.
Outside strict ISO C mode (
, ,
bzero dcgettext
fprintf_unlocked
, , , ,
j0 j1f j1l j1 jnf
, ,
scalbf scalbl scalb
, ,
sincos stpcpy strdup
as built-in functions. All these functions have corresponding versions prefixed with
which may be used even in strict C89 mode.
The ISO C99 functions
, ,
atanhl atanh cabsf
, ,
cargf cargl carg
, ,
catanhl catanh
, ,
ccosl ccos cexpf
,
copysignl copysign
, ,
csinf csinhf csinhl
, ,
ctanhl ctanh ctanl
, ,
expm1f expm1l expm1
, ,
fminl fmin hypotf
, ,
lgamma llabs llrintf
, ,
log1p log2f log2l
,
lround nearbyintf
,
nexttowardf nexttowardl
, ,
remquol remquo
,
scalbln scalbnf
, ,
truncl trunc vfscanf
except in strict ISO C90 mode (
There are also built-in versions of the ISO C99 functions
, ,
atan2l atanf atanl
, ,
floorf floorl fmodf
, ,
logl modfl modf
and that are recognized in any mode since ISO C90 reserves these names for the
tanhl tanl
purpose to which ISO C99 puts them. All these functions have corresponding versions prefixed with
.
__builtin_
The ISO C90 functions
, , ,
exp fabs floor fmod
, ,
memcmp memcpy memset
, ,
sprintf sqrt sscanf
,
strncmp strncpy
and are all recognized as built-in functions unless
vsprintf
-fno-builtin-
function
corresponding versions prefixed with
will always be treated as having the same meaning as the C library function
option. (Section 4.4 Options Controlling C Dialect) Many of
-fno-builtin
,
-ansi -std=c89
, ,
dgettext dremf dreml
,
fputs_unlocked
, , ,
jnl jn mempcpy
,
significandf
, ,
strfmon y0f
,
_Exit acoshf
, , ,
cabsl cabs
, ,
casinf casinhf
, ,
catanl catan cbrtf
, , ,
cexpl cexp cimagf
, , ,
cpowf cpowl
, ,
csinh csinl
, , ,
ctan erfcf
, ,
fdimf fdiml
, , ,
hypotl hypot
, ,
llrintl llrint
, , ,
log2 logbf logbl
, ,
nearbyintl
,
nexttoward
, ,
rintf rintl rint
, ,
scalbnl scalbn
, ,
vscanf vsnprintf
or
-ansi
, , ,
ceilf ceill
, ,
fmodl frexpf
, , ,
powf powl sinf
, ,
abort abs acos
, ,
fprintf fputs
, , ,
modf pow printf
, ,
strcat strchr
, ,
strpbrk strrchr
is specified for an individual function). All of these functions have
__builtin_
Chapter 6. Extensions to the C Language Family
or ), the functions
-std=c99
, ,
drem exp10f
, , ,
gammaf gammal
, , ,
pow10f pow10l
, ,
significandl
, , , ,
y0l y0 y1f y1l
, , ,
acoshl acosh
, ,
cacosf cacoshf
, ,
casinhl casinh
, ,
cbrtl cbrt
, ,
cimagl cimag
, ,
cpow cprojf cprojl
, ,
csin csqrtf
, ,
erfcl erfc erff
, , ,
fdim fmaf fmal
, ,
ilogbf ilogbl ilogb
, ,
llroundf llroundl
, , ,
logb lrintf
,
nearbyint nextafterf
, ,
remainderf
, ,
roundf roundl
, ,
snprintf tgammaf
and
vsscanf
).
-std=c89
acosf
, ,
cosf coshf coshl
, ,
frexpl ldexpf
, , ,
sinhf sinhl sinl
, , ,
asin atan2 atan
, ,
frexp fscanf
, ,
putchar puts
, ,
strcmp strcpy
, ,
strspn strstr
.
_exit
, , ,
exp10l exp10 ffsll
, ,
gamma gettext index
,
pow10 printf_unlocked
,
significand sincosf
, , , and
y1 ynf ynl yn
, ,
asinhf asinhl
, ,
cacoshl cacosh
, , ,
casinl casin catanf
, , ,
ccosf ccoshf
, , ,
conjf conjl conj
, , ,
cproj crealf
, , ,
csqrtl csqrt
, , ,
erfl erf exp2f
, , ,
fmaxf fmaxl fmax
, ,
imaxabs lgammaf
, ,
llround log1pf
, ,
lrintl lrint lroundf
,
nextafterl
,
remainderl remainder
, ,
round scalblnf
, ,
tgammal tgamma
are handled as built-in functions
, , ,
acosl asinf
, , ,
cosl expf expl
, ,
ldexpl log10f
, ,
sqrtf sqrtl
, , ,
calloc ceil cosh
, , ,
labs ldexp log10
, , ,
scanf sinh
, ,
strcspn strlen
, , ,
tanh tan vfprintf
-fno-builtin
, , ,
alloca bcmp
, , ,
ffsl ffs
, , ,
j0f j0l
, ,
rindex
, ,
sincosl
may be handled
,
__builtin_
, ,
asinh atanhf
, ,
cacosl cacos
, ,
catanhf
, ,
ccoshl ccosh
, ,
copysignf
, ,
creall creal
, ,
ctanf ctanhf
, , ,
exp2l exp2
, , ,
fma fminf
, ,
lgammal
, ,
log1pl
, ,
lroundl
, ,
nextafter
, ,
remquof
, ,
scalblnl
, ,
truncf
, ,
asinl atan2f
, , ,
fabsf fabsl
, , ,
log10l logf
, , ,
tanf tanhf
, , ,
cos exit
, , ,
log malloc
, ,
sin snprintf
, ,
strncat
,
vprintf
is specified (or