The compiler offers builtin constants and functions. Some are only available on certain targets. All builtins use the $$ name prefix.

Builtin constants

These can all safely be used by the user.


The current line as an integer.


The current function name, will return "" on the global level.


The current file name.


Usually the same as $$LINE, but in case of a macro inclusion it returns the line in the macro rather than the line where the macro was included.

Builtin functions

These functions are not guaranteed to exist on all platforms. They are intended for use standard library use, and typically the standard library has macros that wrap these builtins, so they should not be used on its own.


Emits a trap instruction.


Inserts an "unreachable" annotation.


Returns the current "callstack" reference if available. Compiler dependent.


Takes a variable and a value and stores the value as a volatile store.


Takes a variable and returns the value using a volatile load.


Builtin memcpy instruction.


Builtin memset instruction.


Prefetch a memory location.


Access to the cycle counter register (or similar low latency clock) on supported architectures (e.g. RDTSC on x86), otherwise $$sysclock will yield 0.


Makes a syscall according to the platform convention on platforms where it is supported.

Math functions

Functions $$ceil, $$trunc, $$sin, $$cos, $$log, $$log2, $$log10, $$rint, $$round $$sqrt, $$roundeven, $$floor, $$sqrt, $$pow, $$exp, $$fma and $$fabs, $$copysign, $$round, $$nearbyint.

Can be applied to float vectors or numbers. Returns the same type.

Functions $$min, $$abs and $$max can be applied to any integer or float number or vector.

Function $pow_int takes a float or floating vector + an integer and returns the same type as the first parameter.

Saturated addition, subtraction and left shift for integers and integer vectors: $$sat_add, $$sat_shl, $$sat_sub.

Bit functions

$$fshl and $$fshr

Funnel shift left and right, takes either two integers or two integer vectors.

$$ctz, $$clz, $$bitreverse, $$bswap, $$popcount

Bit functions work on an integer or an integer vector.

Vector functions

$$reduce_add, $$reduce_mul, $$reduce_and, $$reduce_or, $$reduce_xor work on integer vectors.

$$reduce_fadd, $$reduce_fmul works on float vectors.

$$reduce_max, $$reduce_min works on any vector.

$$reverse reverses the values in any vector.

$$shufflevector rearranges the values of two vectors using a fixed mask into a resulting vector.