A new builtin function __builtin_isfpclass is added. It is called as:

__builtin_isfpclass(<floating point value>, <test>)

and returns an integer value, which is non-zero if the floating point

argument falls into one of the classes specified by the second argument,

and zero otherwise. The set of classes is an integer value, where each

value class is represented by a bit. There are ten data classes, as

defined by the IEEE-754 standard, they are represented by bits:

0x0001 (__FPCLASS_SNAN) - Signaling NaN 0x0002 (__FPCLASS_QNAN) - Quiet NaN 0x0004 (__FPCLASS_NEGINF) - Negative infinity 0x0008 (__FPCLASS_NEGNORMAL) - Negative normal 0x0010 (__FPCLASS_NEGSUBNORMAL) - Negative subnormal 0x0020 (__FPCLASS_NEGZERO) - Negative zero 0x0040 (__FPCLASS_POSZERO) - Positive zero 0x0080 (__FPCLASS_POSSUBNORMAL) - Positive subnormal 0x0100 (__FPCLASS_POSNORMAL) - Positive normal 0x0200 (__FPCLASS_POSINF) - Positive infinity

They have corresponding builtin macros to facilitate using the builtin

function:

if (__builtin_isfpclass(x, __FPCLASS_NEGZERO | __FPCLASS_POSZERO) { // x is any zero. }

The data class encoding is identical to that used in llvm.is.fpclass

function.