Module std::intrinsics

Unstable (core_intrinsics)

: intrinsics are unlikely to ever be stabilized, instead they should be used through stabilized interfaces in the rest of the standard library

rustc compiler intrinsics.

The corresponding definitions are in librustc_trans/trans/intrinsic.rs.

Volatiles

The volatile intrinsics provide operations intended to act on I/O memory, which are guaranteed to not be reordered by the compiler across other volatile intrinsics. See the LLVM documentation on [volatile].

Atomics

The atomic intrinsics provide common atomic operations on machine words, with multiple possible memory orderings. They obey the same semantics as C++11. See the LLVM documentation on [atomics].

A quick refresher on memory ordering:

• Acquire - a barrier for acquiring a lock. Subsequent reads and writes take place after the barrier.
• Release - a barrier for releasing a lock. Preceding reads and writes take place before the barrier.
• Sequentially consistent - sequentially consistent operations are guaranteed to happen in order. This is the standard mode for working with atomic types and is equivalent to Java's volatile.

Functions

copy	Copies count * size_of<T> bytes from src to dst. The source and destination may overlap.
copy_nonoverlapping	Copies count * size_of<T> bytes from src to dst. The source and destination may not overlap.
drop_in_place	Executes the destructor (if any) of the pointed-to value.
transmute	Unsafely transforms a value of one type into a value of another type.
write_bytes	Invokes memset on the specified pointer, setting count * size_of::<T>() bytes of memory starting at dst to val.
abort	[Unstable] Aborts the execution of the process.
add_with_overflow	[Unstable] Performs checked integer addition.
arith_offset	[Unstable] Calculates the offset from a pointer, potentially wrapping.
assume	[Unstable] Informs the optimizer that a condition is always true. If the condition is false, the behavior is undefined.
atomic_and	[Unstable]
atomic_and_acq	[Unstable]
atomic_and_acqrel	[Unstable]
atomic_and_rel	[Unstable]
atomic_and_relaxed	[Unstable]
atomic_cxchg	[Unstable]
atomic_cxchg_acq	[Unstable]
atomic_cxchg_acq_failrelaxed	[Unstable]
atomic_cxchg_acqrel	[Unstable]
atomic_cxchg_acqrel_failrelaxed	[Unstable]
atomic_cxchg_failacq	[Unstable]
atomic_cxchg_failrelaxed	[Unstable]
atomic_cxchg_rel	[Unstable]
atomic_cxchg_relaxed	[Unstable]
atomic_cxchgweak	[Unstable]
atomic_cxchgweak_acq	[Unstable]
atomic_cxchgweak_acq_failrelaxed	[Unstable]
atomic_cxchgweak_acqrel	[Unstable]
atomic_cxchgweak_acqrel_failrelaxed	[Unstable]
atomic_cxchgweak_failacq	[Unstable]
atomic_cxchgweak_failrelaxed	[Unstable]
atomic_cxchgweak_rel	[Unstable]
atomic_cxchgweak_relaxed	[Unstable]
atomic_fence	[Unstable]
atomic_fence_acq	[Unstable]
atomic_fence_acqrel	[Unstable]
atomic_fence_rel	[Unstable]
atomic_load	[Unstable]
atomic_load_acq	[Unstable]
atomic_load_relaxed	[Unstable]
atomic_load_unordered	[Unstable]
atomic_max	[Unstable]
atomic_max_acq	[Unstable]
atomic_max_acqrel	[Unstable]
atomic_max_rel	[Unstable]
atomic_max_relaxed	[Unstable]
atomic_min	[Unstable]
atomic_min_acq	[Unstable]
atomic_min_acqrel	[Unstable]
atomic_min_rel	[Unstable]
atomic_min_relaxed	[Unstable]
atomic_nand	[Unstable]
atomic_nand_acq	[Unstable]
atomic_nand_acqrel	[Unstable]
atomic_nand_rel	[Unstable]
atomic_nand_relaxed	[Unstable]
atomic_or	[Unstable]
atomic_or_acq	[Unstable]
atomic_or_acqrel	[Unstable]
atomic_or_rel	[Unstable]
atomic_or_relaxed	[Unstable]
atomic_singlethreadfence	[Unstable] A compiler-only memory barrier.
atomic_singlethreadfence_acq	[Unstable]
atomic_singlethreadfence_acqrel	[Unstable]
atomic_singlethreadfence_rel	[Unstable]
atomic_store	[Unstable]
atomic_store_rel	[Unstable]
atomic_store_relaxed	[Unstable]
atomic_store_unordered	[Unstable]
atomic_umax	[Unstable]
atomic_umax_acq	[Unstable]
atomic_umax_acqrel	[Unstable]
atomic_umax_rel	[Unstable]
atomic_umax_relaxed	[Unstable]
atomic_umin	[Unstable]
atomic_umin_acq	[Unstable]
atomic_umin_acqrel	[Unstable]
atomic_umin_rel	[Unstable]
atomic_umin_relaxed	[Unstable]
atomic_xadd	[Unstable]
atomic_xadd_acq	[Unstable]
atomic_xadd_acqrel	[Unstable]
atomic_xadd_rel	[Unstable]
atomic_xadd_relaxed	[Unstable]
atomic_xchg	[Unstable]
atomic_xchg_acq	[Unstable]
atomic_xchg_acqrel	[Unstable]
atomic_xchg_rel	[Unstable]
atomic_xchg_relaxed	[Unstable]
atomic_xor	[Unstable]
atomic_xor_acq	[Unstable]
atomic_xor_acqrel	[Unstable]
atomic_xor_rel	[Unstable]
atomic_xor_relaxed	[Unstable]
atomic_xsub	[Unstable]
atomic_xsub_acq	[Unstable]
atomic_xsub_acqrel	[Unstable]
atomic_xsub_rel	[Unstable]
atomic_xsub_relaxed	[Unstable]
breakpoint	[Unstable] Executes a breakpoint trap, for inspection by a debugger.
bswap	[Unstable] Reverses the bytes in an integer type T.
ceilf32	[Unstable] Returns the smallest integer greater than or equal to an f32.
ceilf64	[Unstable] Returns the smallest integer greater than or equal to an f64.
copysignf32	[Unstable] Copies the sign from y to x for f32 values.
copysignf64	[Unstable] Copies the sign from y to x for f64 values.
cosf32	[Unstable] Returns the cosine of an f32.
cosf64	[Unstable] Returns the cosine of an f64.
ctlz	[Unstable] Returns the number of leading bits unset in an integer type T
ctpop	[Unstable] Returns the number of bits set in an integer type T
cttz	[Unstable] Returns the number of trailing bits unset in an integer type T
discriminant_value	[Unstable] Returns the value of the discriminant for the variant in 'v', cast to a u64; if T has no discriminant, returns 0.
exp2f32	[Unstable] Returns 2 raised to the power of an f32.
exp2f64	[Unstable] Returns 2 raised to the power of an f64.
expf32	[Unstable] Returns the exponential of an f32.
expf64	[Unstable] Returns the exponential of an f64.
fabsf32	[Unstable] Returns the absolute value of an f32.
fabsf64	[Unstable] Returns the absolute value of an f64.
fadd_fast	[Unstable] Float addition that allows optimizations based on algebraic rules. May assume inputs are finite.
fdiv_fast	[Unstable] Float division that allows optimizations based on algebraic rules. May assume inputs are finite.
floorf32	[Unstable] Returns the largest integer less than or equal to an f32.
floorf64	[Unstable] Returns the largest integer less than or equal to an f64.
fmaf32	[Unstable] Returns a * b + c for f32 values.
fmaf64	[Unstable] Returns a * b + c for f64 values.
fmul_fast	[Unstable] Float multiplication that allows optimizations based on algebraic rules. May assume inputs are finite.
forget	[Unstable] Moves a value out of scope without running drop glue.
frem_fast	[Unstable] Float remainder that allows optimizations based on algebraic rules. May assume inputs are finite.
fsub_fast	[Unstable] Float subtraction that allows optimizations based on algebraic rules. May assume inputs are finite.
init	[Unstable] Creates a value initialized to zero.
init_dropped	[Unstable] Creates a value initialized to so that its drop flag, if any, says that it has been dropped.
log10f32	[Unstable] Returns the base 10 logarithm of an f32.
log10f64	[Unstable] Returns the base 10 logarithm of an f64.
log2f32	[Unstable] Returns the base 2 logarithm of an f32.
log2f64	[Unstable] Returns the base 2 logarithm of an f64.
logf32	[Unstable] Returns the natural logarithm of an f32.
logf64	[Unstable] Returns the natural logarithm of an f64.
min_align_of	[Unstable]
min_align_of_val	[Unstable]
move_val_init	[Unstable] Moves a value to an uninitialized memory location.
mul_with_overflow	[Unstable] Performs checked integer multiplication
nearbyintf32	[Unstable] Returns the nearest integer to an f32.
nearbyintf64	[Unstable] Returns the nearest integer to an f64.
needs_drop	[Unstable] Returns true if the actual type given as T requires drop glue; returns false if the actual type provided for T implements Copy.
offset	[Unstable] Calculates the offset from a pointer.
overflowing_add	[Unstable] Returns (a + b) mod 2N, where N is the width of T in bits.
overflowing_mul	[Unstable] Returns (a * b) mod 2N, where N is the width of T in bits.
overflowing_sub	[Unstable] Returns (a - b) mod 2N, where N is the width of T in bits.
powf32	[Unstable] Raises an f32 to an f32 power.
powf64	[Unstable] Raises an f64 to an f64 power.
powif32	[Unstable] Raises an f32 to an integer power.
powif64	[Unstable] Raises an f64 to an integer power.
pref_align_of	[Unstable]
return_address	[Unstable] Gives the address for the return value of the enclosing function.
rintf32	[Unstable] Returns the nearest integer to an f32. May raise an inexact floating-point exception if the argument is not an integer.
rintf64	[Unstable] Returns the nearest integer to an f64. May raise an inexact floating-point exception if the argument is not an integer.
roundf32	[Unstable] Returns the nearest integer to an f32. Rounds half-way cases away from zero.
roundf64	[Unstable] Returns the nearest integer to an f64. Rounds half-way cases away from zero.
sinf32	[Unstable] Returns the sine of an f32.
sinf64	[Unstable] Returns the sine of an f64.
size_of	[Unstable] The size of a type in bytes.
size_of_val	[Unstable]
sqrtf32	[Unstable] Returns the square root of an f32
sqrtf64	[Unstable] Returns the square root of an f64
sub_with_overflow	[Unstable] Performs checked integer subtraction
truncf32	[Unstable] Returns the integer part of an f32.
truncf64	[Unstable] Returns the integer part of an f64.
try	[Unstable] Rust's "try catch" construct which invokes the function pointer f with the data pointer data.
type_id	[Unstable] Gets an identifier which is globally unique to the specified type. This function will return the same value for a type regardless of whichever crate it is invoked in.
type_name	[Unstable] Gets a static string slice containing the name of a type.
unchecked_div	[Unstable] Performs an unchecked division, resulting in undefined behavior where y = 0 or x = T::min_value() and y = -1
unchecked_rem	[Unstable] Returns the remainder of an unchecked division, resulting in undefined behavior where y = 0 or x = T::min_value() and y = -1
uninit	[Unstable] Creates an uninitialized value.
unreachable	[Unstable] Tells LLVM that this point in the code is not reachable, enabling further optimizations.
volatile_copy_memory	[Unstable] Equivalent to the appropriate llvm.memmove.p0i8.0i8.* intrinsic, with a size of count * size_of::<T>() and an alignment of min_align_of::<T>()
volatile_copy_nonoverlapping_memory	[Unstable] Equivalent to the appropriate llvm.memcpy.p0i8.0i8.* intrinsic, with a size of count * size_of::<T>() and an alignment of min_align_of::<T>()
volatile_load	[Unstable] Perform a volatile load from the src pointer.
volatile_set_memory	[Unstable] Equivalent to the appropriate llvm.memset.p0i8.* intrinsic, with a size of count * size_of::<T>() and an alignment of min_align_of::<T>().
volatile_store	[Unstable] Perform a volatile store to the dst pointer.