Module std::intrinsics

Unstable

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.
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 c.
abort	[Unstable] Aborts the execution of the process.
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_acqrel	[Unstable]
atomic_cxchg_rel	[Unstable]
atomic_cxchg_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.
bswap16	[Unstable] Reverses the bytes in a u16.
bswap32	[Unstable] Reverses the bytes in a u32.
bswap64	[Unstable] Reverses the bytes in a u64.
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.
ctlz16	[Unstable] Returns the number of leading bits unset in a u16.
ctlz32	[Unstable] Returns the number of leading bits unset in a u32.
ctlz64	[Unstable] Returns the number of leading bits unset in a u64.
ctlz8	[Unstable] Returns the number of leading bits unset in a u8.
ctpop16	[Unstable] Returns the number of bits set in a u16.
ctpop32	[Unstable] Returns the number of bits set in a u32.
ctpop64	[Unstable] Returns the number of bits set in a u64.
ctpop8	[Unstable] Returns the number of bits set in a u8.
cttz16	[Unstable] Returns the number of trailing bits unset in a u16.
cttz32	[Unstable] Returns the number of trailing bits unset in a u32.
cttz64	[Unstable] Returns the number of trailing bits unset in a u64.
cttz8	[Unstable] Returns the number of trailing bits unset in a u8.
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.
drop_in_place	[Unstable]
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.
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.
forget	[Unstable] Moves a value out of scope without running drop glue.
i16_add_with_overflow	[Unstable] Performs checked i16 addition.
i16_mul_with_overflow	[Unstable] Performs checked i16 multiplication.
i16_sub_with_overflow	[Unstable] Performs checked i16 subtraction.
i32_add_with_overflow	[Unstable] Performs checked i32 addition.
i32_mul_with_overflow	[Unstable] Performs checked i32 multiplication.
i32_sub_with_overflow	[Unstable] Performs checked i32 subtraction.
i64_add_with_overflow	[Unstable] Performs checked i64 addition.
i64_mul_with_overflow	[Unstable] Performs checked i64 multiplication.
i64_sub_with_overflow	[Unstable] Performs checked i64 subtraction.
i8_add_with_overflow	[Unstable] Performs checked i8 addition.
i8_mul_with_overflow	[Unstable] Performs checked i8 multiplication.
i8_sub_with_overflow	[Unstable] Performs checked i8 subtraction.
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.
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 N in bits.
overflowing_mul	[Unstable] Returns (a * b) mod 2N, where N is the width of N in bits.
overflowing_sub	[Unstable] Returns (a - b) mod 2N, where N is the width of N 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
truncf32	[Unstable] Returns the integer part of an f32.
truncf64	[Unstable] Returns the integer part of an f64.
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.
u16_add_with_overflow	[Unstable] Performs checked u16 addition.
u16_mul_with_overflow	[Unstable] Performs checked u16 multiplication.
u16_sub_with_overflow	[Unstable] Performs checked u16 subtraction.
u32_add_with_overflow	[Unstable] Performs checked u32 addition.
u32_mul_with_overflow	[Unstable] Performs checked u32 multiplication.
u32_sub_with_overflow	[Unstable] Performs checked u32 subtraction.
u64_add_with_overflow	[Unstable] Performs checked u64 addition.
u64_mul_with_overflow	[Unstable] Performs checked u64 multiplication.
u64_sub_with_overflow	[Unstable] Performs checked u64 subtraction.
u8_add_with_overflow	[Unstable] Performs checked u8 addition.
u8_mul_with_overflow	[Unstable] Performs checked u8 multiplication.
u8_sub_with_overflow	[Unstable] Performs checked u8 subtraction.
unchecked_sdiv	[Unstable] Performs an unchecked signed division, which results in undefined behavior, in cases where y == 0, or x == int::MIN and y == -1
unchecked_srem	[Unstable] Returns the remainder of an unchecked signed division, which results in undefined behavior, in cases where y == 0
unchecked_udiv	[Unstable] Performs an unchecked unsigned division, which results in undefined behavior, in cases where y == 0
unchecked_urem	[Unstable] Returns the remainder of an unchecked signed division, which results in undefined behavior, in cases where y == 0, or x == int::MIN 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.