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Module std::intrinsics

🔬 This is a nightly-only experimental API. (core_intrinsics #0)intrinsics are unlikely to ever be stabilized, instead they should be used through stabilized interfaces in the rest of the standard library

Compiler intrinsics.

The corresponding definitions are in librustc_codegen_llvm/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

copyâš 

Copies count * size_of::<T>() bytes from src to dst. The source and destination may overlap.
copy_nonoverlappingâš 

Copies count * size_of::<T>() bytes from src to dst. The source and destination must not overlap.
drop_in_placeâš 

Executes the destructor (if any) of the pointed-to value.
transmuteâš 

Reinterprets the bits of a value of one type as another type.
write_bytesâš 

Sets count * size_of::<T>() bytes of memory starting at dst to val.
abortâš  Experimental

Aborts the execution of the process.
add_with_overflow Experimental

Performs checked integer addition. The stabilized versions of this intrinsic are available on the integer primitives via the overflowing_add method. For example, std::u32::overflowing_add
arith_offsetâš  Experimental

Calculates the offset from a pointer, potentially wrapping.
assumeâš  Experimental

Informs the optimizer that a condition is always true. If the condition is false, the behavior is undefined.
atomic_andâš  Experimental

Bitwise and with the current value, returning the previous value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the fetch_and method by passing Ordering::SeqCst as the order. For example, AtomicBool::fetch_and.
atomic_and_acqâš  Experimental

Bitwise and with the current value, returning the previous value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the fetch_and method by passing Ordering::Acquire as the order. For example, AtomicBool::fetch_and.
atomic_and_acqrelâš  Experimental

Bitwise and with the current value, returning the previous value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the fetch_and method by passing Ordering::AcqRel as the order. For example, AtomicBool::fetch_and.
atomic_and_relâš  Experimental

Bitwise and with the current value, returning the previous value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the fetch_and method by passing Ordering::Release as the order. For example, AtomicBool::fetch_and.
atomic_and_relaxedâš  Experimental

Bitwise and with the current value, returning the previous value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the fetch_and method by passing Ordering::Relaxed as the order. For example, AtomicBool::fetch_and.
atomic_cxchgâš  Experimental

Stores a value if the current value is the same as the old value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the compare_exchange method by passing Ordering::SeqCst as both the success and failure parameters. For example, AtomicBool::compare_exchange.
atomic_cxchg_acqâš  Experimental

Stores a value if the current value is the same as the old value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the compare_exchange method by passing Ordering::Acquire as both the success and failure parameters. For example, AtomicBool::compare_exchange.
atomic_cxchg_acq_failrelaxedâš  Experimental

Stores a value if the current value is the same as the old value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the compare_exchange method by passing Ordering::Acquire as the success and Ordering::Relaxed as the failure parameters. For example, AtomicBool::compare_exchange.
atomic_cxchg_acqrelâš  Experimental

Stores a value if the current value is the same as the old value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the compare_exchange method by passing Ordering::AcqRel as the success and Ordering::Acquire as the failure parameters. For example, AtomicBool::compare_exchange.
atomic_cxchg_acqrel_failrelaxedâš  Experimental

Stores a value if the current value is the same as the old value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the compare_exchange method by passing Ordering::AcqRel as the success and Ordering::Relaxed as the failure parameters. For example, AtomicBool::compare_exchange.
atomic_cxchg_failacqâš  Experimental

Stores a value if the current value is the same as the old value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the compare_exchange method by passing Ordering::SeqCst as the success and Ordering::Acquire as the failure parameters. For example, AtomicBool::compare_exchange.
atomic_cxchg_failrelaxedâš  Experimental

Stores a value if the current value is the same as the old value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the compare_exchange method by passing Ordering::SeqCst as the success and Ordering::Relaxed as the failure parameters. For example, AtomicBool::compare_exchange.
atomic_cxchg_relâš  Experimental

Stores a value if the current value is the same as the old value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the compare_exchange method by passing Ordering::Release as the success and Ordering::Relaxed as the failure parameters. For example, AtomicBool::compare_exchange.
atomic_cxchg_relaxedâš  Experimental

Stores a value if the current value is the same as the old value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the compare_exchange method by passing Ordering::Relaxed as both the success and failure parameters. For example, AtomicBool::compare_exchange.
atomic_cxchgweakâš  Experimental

Stores a value if the current value is the same as the old value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the compare_exchange_weak method by passing Ordering::SeqCst as both the success and failure parameters. For example, AtomicBool::compare_exchange_weak.
atomic_cxchgweak_acqâš  Experimental

Stores a value if the current value is the same as the old value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the compare_exchange_weak method by passing Ordering::Acquire as both the success and failure parameters. For example, AtomicBool::compare_exchange_weak.
atomic_cxchgweak_acq_failrelaxedâš  Experimental

Stores a value if the current value is the same as the old value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the compare_exchange_weak method by passing Ordering::Acquire as the success and Ordering::Relaxed as the failure parameters. For example, AtomicBool::compare_exchange_weak.
atomic_cxchgweak_acqrelâš  Experimental

Stores a value if the current value is the same as the old value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the compare_exchange_weak method by passing Ordering::AcqRel as the success and Ordering::Acquire as the failure parameters. For example, AtomicBool::compare_exchange_weak.
atomic_cxchgweak_acqrel_failrelaxedâš  Experimental

Stores a value if the current value is the same as the old value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the compare_exchange_weak method by passing Ordering::AcqRel as the success and Ordering::Relaxed as the failure parameters. For example, AtomicBool::compare_exchange_weak.
atomic_cxchgweak_failacqâš  Experimental

Stores a value if the current value is the same as the old value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the compare_exchange_weak method by passing Ordering::SeqCst as the success and Ordering::Acquire as the failure parameters. For example, AtomicBool::compare_exchange_weak.
atomic_cxchgweak_failrelaxedâš  Experimental

Stores a value if the current value is the same as the old value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the compare_exchange_weak method by passing Ordering::SeqCst as the success and Ordering::Relaxed as the failure parameters. For example, AtomicBool::compare_exchange_weak.
atomic_cxchgweak_relâš  Experimental

Stores a value if the current value is the same as the old value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the compare_exchange_weak method by passing Ordering::Release as the success and Ordering::Relaxed as the failure parameters. For example, AtomicBool::compare_exchange_weak.
atomic_cxchgweak_relaxedâš  Experimental

Stores a value if the current value is the same as the old value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the compare_exchange_weak method by passing Ordering::Relaxed as both the success and failure parameters. For example, AtomicBool::compare_exchange_weak.
atomic_fenceâš  Experimental
atomic_fence_acqâš  Experimental
atomic_fence_acqrelâš  Experimental
atomic_fence_relâš  Experimental
atomic_loadâš  Experimental

Loads the current value of the pointer. The stabilized version of this intrinsic is available on the std::sync::atomic types via the load method by passing Ordering::SeqCst as the order. For example, AtomicBool::load.
atomic_load_acqâš  Experimental

Loads the current value of the pointer. The stabilized version of this intrinsic is available on the std::sync::atomic types via the load method by passing Ordering::Acquire as the order. For example, AtomicBool::load.
atomic_load_relaxedâš  Experimental

Loads the current value of the pointer. The stabilized version of this intrinsic is available on the std::sync::atomic types via the load method by passing Ordering::Relaxed as the order. For example, AtomicBool::load.
atomic_load_unorderedâš  Experimental
atomic_maxâš  Experimental
atomic_max_acqâš  Experimental
atomic_max_acqrelâš  Experimental
atomic_max_relâš  Experimental
atomic_max_relaxedâš  Experimental
atomic_minâš  Experimental
atomic_min_acqâš  Experimental
atomic_min_acqrelâš  Experimental
atomic_min_relâš  Experimental
atomic_min_relaxedâš  Experimental
atomic_nandâš  Experimental

Bitwise nand with the current value, returning the previous value. The stabilized version of this intrinsic is available on the std::sync::atomic::AtomicBool type via the fetch_nand method by passing Ordering::SeqCst as the order. For example, AtomicBool::fetch_nand.
atomic_nand_acqâš  Experimental

Bitwise nand with the current value, returning the previous value. The stabilized version of this intrinsic is available on the std::sync::atomic::AtomicBool type via the fetch_nand method by passing Ordering::Acquire as the order. For example, AtomicBool::fetch_nand.
atomic_nand_acqrelâš  Experimental

Bitwise nand with the current value, returning the previous value. The stabilized version of this intrinsic is available on the std::sync::atomic::AtomicBool type via the fetch_nand method by passing Ordering::AcqRel as the order. For example, AtomicBool::fetch_nand.
atomic_nand_relâš  Experimental

Bitwise nand with the current value, returning the previous value. The stabilized version of this intrinsic is available on the std::sync::atomic::AtomicBool type via the fetch_nand method by passing Ordering::Release as the order. For example, AtomicBool::fetch_nand.
atomic_nand_relaxedâš  Experimental

Bitwise nand with the current value, returning the previous value. The stabilized version of this intrinsic is available on the std::sync::atomic::AtomicBool type via the fetch_nand method by passing Ordering::Relaxed as the order. For example, AtomicBool::fetch_nand.
atomic_orâš  Experimental

Bitwise or with the current value, returning the previous value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the fetch_or method by passing Ordering::SeqCst as the order. For example, AtomicBool::fetch_or.
atomic_or_acqâš  Experimental

Bitwise or with the current value, returning the previous value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the fetch_or method by passing Ordering::Acquire as the order. For example, AtomicBool::fetch_or.
atomic_or_acqrelâš  Experimental

Bitwise or with the current value, returning the previous value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the fetch_or method by passing Ordering::AcqRel as the order. For example, AtomicBool::fetch_or.
atomic_or_relâš  Experimental

Bitwise or with the current value, returning the previous value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the fetch_or method by passing Ordering::Release as the order. For example, AtomicBool::fetch_or.
atomic_or_relaxedâš  Experimental

Bitwise or with the current value, returning the previous value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the fetch_or method by passing Ordering::Relaxed as the order. For example, AtomicBool::fetch_or.
atomic_singlethreadfenceâš  Experimental

A compiler-only memory barrier.
atomic_singlethreadfence_acqâš  Experimental
atomic_singlethreadfence_acqrelâš  Experimental
atomic_singlethreadfence_relâš  Experimental
atomic_storeâš  Experimental

Stores the value at the specified memory location. The stabilized version of this intrinsic is available on the std::sync::atomic types via the store method by passing Ordering::SeqCst as the order. For example, AtomicBool::store.
atomic_store_relâš  Experimental

Stores the value at the specified memory location. The stabilized version of this intrinsic is available on the std::sync::atomic types via the store method by passing Ordering::Release as the order. For example, AtomicBool::store.
atomic_store_relaxedâš  Experimental

Stores the value at the specified memory location. The stabilized version of this intrinsic is available on the std::sync::atomic types via the store method by passing Ordering::Relaxed as the order. For example, AtomicBool::store.
atomic_store_unorderedâš  Experimental
atomic_umaxâš  Experimental
atomic_umax_acqâš  Experimental
atomic_umax_acqrelâš  Experimental
atomic_umax_relâš  Experimental
atomic_umax_relaxedâš  Experimental
atomic_uminâš  Experimental
atomic_umin_acqâš  Experimental
atomic_umin_acqrelâš  Experimental
atomic_umin_relâš  Experimental
atomic_umin_relaxedâš  Experimental
atomic_xaddâš  Experimental

Adds to the current value, returning the previous value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the fetch_add method by passing Ordering::SeqCst as the order. For example, AtomicIsize::fetch_add.
atomic_xadd_acqâš  Experimental

Adds to the current value, returning the previous value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the fetch_add method by passing Ordering::Acquire as the order. For example, AtomicIsize::fetch_add.
atomic_xadd_acqrelâš  Experimental

Adds to the current value, returning the previous value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the fetch_add method by passing Ordering::AcqRel as the order. For example, AtomicIsize::fetch_add.
atomic_xadd_relâš  Experimental

Adds to the current value, returning the previous value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the fetch_add method by passing Ordering::Release as the order. For example, AtomicIsize::fetch_add.
atomic_xadd_relaxedâš  Experimental

Adds to the current value, returning the previous value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the fetch_add method by passing Ordering::Relaxed as the order. For example, AtomicIsize::fetch_add.
atomic_xchgâš  Experimental

Stores the value at the specified memory location, returning the old value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the swap method by passing Ordering::SeqCst as the order. For example, AtomicBool::swap.
atomic_xchg_acqâš  Experimental

Stores the value at the specified memory location, returning the old value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the swap method by passing Ordering::Acquire as the order. For example, AtomicBool::swap.
atomic_xchg_acqrelâš  Experimental

Stores the value at the specified memory location, returning the old value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the swap method by passing Ordering::AcqRel as the order. For example, AtomicBool::swap.
atomic_xchg_relâš  Experimental

Stores the value at the specified memory location, returning the old value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the swap method by passing Ordering::Release as the order. For example, AtomicBool::swap.
atomic_xchg_relaxedâš  Experimental

Stores the value at the specified memory location, returning the old value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the swap method by passing Ordering::Relaxed as the order. For example, AtomicBool::swap.
atomic_xorâš  Experimental

Bitwise xor with the current value, returning the previous value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the fetch_xor method by passing Ordering::SeqCst as the order. For example, AtomicBool::fetch_xor.
atomic_xor_acqâš  Experimental

Bitwise xor with the current value, returning the previous value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the fetch_xor method by passing Ordering::Acquire as the order. For example, AtomicBool::fetch_xor.
atomic_xor_acqrelâš  Experimental

Bitwise xor with the current value, returning the previous value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the fetch_xor method by passing Ordering::AcqRel as the order. For example, AtomicBool::fetch_xor.
atomic_xor_relâš  Experimental

Bitwise xor with the current value, returning the previous value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the fetch_xor method by passing Ordering::Release as the order. For example, AtomicBool::fetch_xor.
atomic_xor_relaxedâš  Experimental

Bitwise xor with the current value, returning the previous value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the fetch_xor method by passing Ordering::Relaxed as the order. For example, AtomicBool::fetch_xor.
atomic_xsubâš  Experimental

Subtract from the current value, returning the previous value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the fetch_sub method by passing Ordering::SeqCst as the order. For example, AtomicIsize::fetch_sub.
atomic_xsub_acqâš  Experimental

Subtract from the current value, returning the previous value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the fetch_sub method by passing Ordering::Acquire as the order. For example, AtomicIsize::fetch_sub.
atomic_xsub_acqrelâš  Experimental

Subtract from the current value, returning the previous value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the fetch_sub method by passing Ordering::AcqRel as the order. For example, AtomicIsize::fetch_sub.
atomic_xsub_relâš  Experimental

Subtract from the current value, returning the previous value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the fetch_sub method by passing Ordering::Release as the order. For example, AtomicIsize::fetch_sub.
atomic_xsub_relaxedâš  Experimental

Subtract from the current value, returning the previous value. The stabilized version of this intrinsic is available on the std::sync::atomic types via the fetch_sub method by passing Ordering::Relaxed as the order. For example, AtomicIsize::fetch_sub.
bitreverse Experimental

Reverses the bits in an integer type T.
breakpointâš  Experimental

Executes a breakpoint trap, for inspection by a debugger.
bswap Experimental

Reverses the bytes in an integer type T.
ceilf32âš  Experimental

Returns the smallest integer greater than or equal to an f32.
ceilf64âš  Experimental

Returns the smallest integer greater than or equal to an f64.
copysignf32âš  Experimental

Copies the sign from y to x for f32 values.
copysignf64âš  Experimental

Copies the sign from y to x for f64 values.
cosf32âš  Experimental

Returns the cosine of an f32.
cosf64âš  Experimental

Returns the cosine of an f64.
ctlz Experimental

Returns the number of leading unset bits (zeroes) in an integer type T.
ctlz_nonzeroâš  Experimental

Like ctlz, but extra-unsafe as it returns undef when given an x with value 0.
ctpop Experimental

Returns the number of bits set in an integer type T
cttz Experimental

Returns the number of trailing unset bits (zeroes) in an integer type T.
cttz_nonzeroâš  Experimental

Like cttz, but extra-unsafe as it returns undef when given an x with value 0.
discriminant_valueâš  Experimental

Returns the value of the discriminant for the variant in 'v', cast to a u64; if T has no discriminant, returns 0.
exact_divâš  Experimental

Performs an exact division, resulting in undefined behavior where x % y != 0 or y == 0 or x == T::min_value() && y == -1
exp2f32âš  Experimental

Returns 2 raised to the power of an f32.
exp2f64âš  Experimental

Returns 2 raised to the power of an f64.
expf32âš  Experimental

Returns the exponential of an f32.
expf64âš  Experimental

Returns the exponential of an f64.
fabsf32âš  Experimental

Returns the absolute value of an f32.
fabsf64âš  Experimental

Returns the absolute value of an f64.
fadd_fastâš  Experimental

Float addition that allows optimizations based on algebraic rules. May assume inputs are finite.
fdiv_fastâš  Experimental

Float division that allows optimizations based on algebraic rules. May assume inputs are finite.
floorf32âš  Experimental

Returns the largest integer less than or equal to an f32.
floorf64âš  Experimental

Returns the largest integer less than or equal to an f64.
fmaf32âš  Experimental

Returns a * b + c for f32 values.
fmaf64âš  Experimental

Returns a * b + c for f64 values.
fmul_fastâš  Experimental

Float multiplication that allows optimizations based on algebraic rules. May assume inputs are finite.
forgetâš  Experimental

Moves a value out of scope without running drop glue.
frem_fastâš  Experimental

Float remainder that allows optimizations based on algebraic rules. May assume inputs are finite.
fsub_fastâš  Experimental

Float subtraction that allows optimizations based on algebraic rules. May assume inputs are finite.
initâš  Experimental

Creates a value initialized to zero.
likelyâš  Experimental

Hints to the compiler that branch condition is likely to be true. Returns the value passed to it.
log10f32âš  Experimental

Returns the base 10 logarithm of an f32.
log10f64âš  Experimental

Returns the base 10 logarithm of an f64.
log2f32âš  Experimental

Returns the base 2 logarithm of an f32.
log2f64âš  Experimental

Returns the base 2 logarithm of an f64.
logf32âš  Experimental

Returns the natural logarithm of an f32.
logf64âš  Experimental

Returns the natural logarithm of an f64.
maxnumf32 Experimental

Returns the maximum of two f32 values.
maxnumf64 Experimental

Returns the maximum of two f64 values.
min_align_of Experimental
min_align_of_valâš  Experimental
minnumf32 Experimental

Returns the minimum of two f32 values.
minnumf64 Experimental

Returns the minimum of two f64 values.
move_val_initâš  Experimental

Moves a value to an uninitialized memory location.
mul_with_overflow Experimental

Performs checked integer multiplication The stabilized versions of this intrinsic are available on the integer primitives via the overflowing_mul method. For example, std::u32::overflowing_mul
nearbyintf32âš  Experimental

Returns the nearest integer to an f32.
nearbyintf64âš  Experimental

Returns the nearest integer to an f64.
needs_drop Experimental

Returns true if the actual type given as T requires drop glue; returns false if the actual type provided for T implements Copy.
nontemporal_storeâš  Experimental

Emits a !nontemporal store according to LLVM (see their docs). Probably will never become stable.
offsetâš  Experimental

Calculates the offset from a pointer.
overflowing_add Experimental

Returns (a + b) mod 2N, where N is the width of T in bits. The stabilized versions of this intrinsic are available on the integer primitives via the wrapping_add method. For example, std::u32::wrapping_add
overflowing_mul Experimental

Returns (a * b) mod 2N, where N is the width of T in bits. The stabilized versions of this intrinsic are available on the integer primitives via the wrapping_mul method. For example, std::u32::wrapping_mul
overflowing_sub Experimental

Returns (a - b) mod 2N, where N is the width of T in bits. The stabilized versions of this intrinsic are available on the integer primitives via the wrapping_sub method. For example, std::u32::wrapping_sub
panic_if_uninhabitedâš  Experimental

A guard for unsafe functions that cannot ever be executed if T is uninhabited: This will statically either panic, or do nothing.
powf32âš  Experimental

Raises an f32 to an f32 power.
powf64âš  Experimental

Raises an f64 to an f64 power.
powif32âš  Experimental

Raises an f32 to an integer power.
powif64âš  Experimental

Raises an f64 to an integer power.
pref_align_ofâš  Experimental
prefetch_read_dataâš  Experimental

The prefetch intrinsic is a hint to the code generator to insert a prefetch instruction if supported; otherwise, it is a no-op. Prefetches have no effect on the behavior of the program but can change its performance characteristics.
prefetch_read_instructionâš  Experimental

The prefetch intrinsic is a hint to the code generator to insert a prefetch instruction if supported; otherwise, it is a no-op. Prefetches have no effect on the behavior of the program but can change its performance characteristics.
prefetch_write_dataâš  Experimental

The prefetch intrinsic is a hint to the code generator to insert a prefetch instruction if supported; otherwise, it is a no-op. Prefetches have no effect on the behavior of the program but can change its performance characteristics.
prefetch_write_instructionâš  Experimental

The prefetch intrinsic is a hint to the code generator to insert a prefetch instruction if supported; otherwise, it is a no-op. Prefetches have no effect on the behavior of the program but can change its performance characteristics.
rintf32âš  Experimental

Returns the nearest integer to an f32. May raise an inexact floating-point exception if the argument is not an integer.
rintf64âš  Experimental

Returns the nearest integer to an f64. May raise an inexact floating-point exception if the argument is not an integer.
rotate_left Experimental

Performs rotate left. The stabilized versions of this intrinsic are available on the integer primitives via the rotate_left method. For example, std::u32::rotate_left
rotate_right Experimental

Performs rotate right. The stabilized versions of this intrinsic are available on the integer primitives via the rotate_right method. For example, std::u32::rotate_right
roundf32âš  Experimental

Returns the nearest integer to an f32. Rounds half-way cases away from zero.
roundf64âš  Experimental

Returns the nearest integer to an f64. Rounds half-way cases away from zero.
rustc_peekâš  Experimental

Magic intrinsic that derives its meaning from attributes attached to the function.
saturating_add Experimental

Computes a + b, while saturating at numeric bounds. The stabilized versions of this intrinsic are available on the integer primitives via the saturating_add method. For example, std::u32::saturating_add
saturating_sub Experimental

Computes a - b, while saturating at numeric bounds. The stabilized versions of this intrinsic are available on the integer primitives via the saturating_sub method. For example, std::u32::saturating_sub
sinf32âš  Experimental

Returns the sine of an f32.
sinf64âš  Experimental

Returns the sine of an f64.
size_of Experimental

The size of a type in bytes.
size_of_valâš  Experimental

The size of the referenced value in bytes.
sqrtf32âš  Experimental

Returns the square root of an f32
sqrtf64âš  Experimental

Returns the square root of an f64
sub_with_overflow Experimental

Performs checked integer subtraction The stabilized versions of this intrinsic are available on the integer primitives via the overflowing_sub method. For example, std::u32::overflowing_sub
truncf32âš  Experimental

Returns the integer part of an f32.
truncf64âš  Experimental

Returns the integer part of an f64.
tryâš  Experimental

Rust's "try catch" construct which invokes the function pointer f with the data pointer data.
type_idâš  Experimental

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_nameâš  Experimental

Gets a static string slice containing the name of a type.
unaligned_volatile_loadâš  Experimental

Performs a volatile load from the src pointer The pointer is not required to be aligned.
unaligned_volatile_storeâš  Experimental

Performs a volatile store to the dst pointer. The pointer is not required to be aligned.
unchecked_addâš  Experimental

Returns the result of an unchecked addition, resulting in undefined behavior when x + y > T::max_value() or x + y < T::min_value().
unchecked_divâš  Experimental

Performs an unchecked division, resulting in undefined behavior where y = 0 or x = T::min_value() and y = -1
unchecked_mulâš  Experimental

Returns the result of an unchecked multiplication, resulting in undefined behavior when x * y > T::max_value() or x * y < T::min_value().
unchecked_remâš  Experimental

Returns the remainder of an unchecked division, resulting in undefined behavior where y = 0 or x = T::min_value() and y = -1
unchecked_shlâš  Experimental

Performs an unchecked left shift, resulting in undefined behavior when y < 0 or y >= N, where N is the width of T in bits.
unchecked_shrâš  Experimental

Performs an unchecked right shift, resulting in undefined behavior when y < 0 or y >= N, where N is the width of T in bits.
unchecked_subâš  Experimental

Returns the result of an unchecked substraction, resulting in undefined behavior when x - y > T::max_value() or x - y < T::min_value().
uninitâš  Experimental

Creates an uninitialized value.
unlikelyâš  Experimental

Hints to the compiler that branch condition is likely to be false. Returns the value passed to it.
unreachableâš  Experimental

Tells LLVM that this point in the code is not reachable, enabling further optimizations.
volatile_copy_memoryâš  Experimental

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_memoryâš  Experimental

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_loadâš  Experimental

Performs a volatile load from the src pointer. The stabilized version of this intrinsic is std::ptr::read_volatile.
volatile_set_memoryâš  Experimental

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_storeâš  Experimental

Performs a volatile store to the dst pointer. The stabilized version of this intrinsic is std::ptr::write_volatile.

© 2010 The Rust Project Developers
Licensed under the Apache License, Version 2.0 or the MIT license, at your option.
https://doc.rust-lang.org/std/intrinsics/index.html