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Diffstat (limited to 'gcc/doc/extend.texi')
| -rw-r--r-- | gcc/doc/extend.texi | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi index 786c18d..cf7fdbf 100644 --- a/gcc/doc/extend.texi +++ b/gcc/doc/extend.texi @@ -7511,6 +7511,18 @@ future revisions. @end deftypefn +@deftypefn {Built-in Function} @var{type} __builtin_complex (@var{real}, @var{imag}) + +The built-in function @code{__builtin_complex} is provided for use in +implementing the ISO C1X macros @code{CMPLXF}, @code{CMPLX} and +@code{CMPLXL}. @var{real} and @var{imag} must have the same type, a +real binary floating-point type, and the result has the corresponding +complex type with real and imaginary parts @var{real} and @var{imag}. +Unlike @samp{@var{real} + I * @var{imag}}, this works even when +infinities, NaNs and negative zeros are involved. + +@end deftypefn + @deftypefn {Built-in Function} int __builtin_constant_p (@var{exp}) You can use the built-in function @code{__builtin_constant_p} to determine if a value is known to be constant at compile-time and hence |