Bswap32 returns its input with byte order reversed 0x01020304 -> 0x04030201.

Bswap64 returns its input with byte order reversed 0x0102030405060708 -> 0x0807060504030201.

LeadingZeros64 returns the number of leading zero bits in x; the result is 64 for x == 0.

LeadingZeros8 returns the number of leading zero bits in x; the result is 8 for x == 0.

Len64 returns the minimum number of bits required to represent x; the result is 0 for x == 0.

Len8 returns the minimum number of bits required to represent x; the result is 0 for x == 0.

OnesCount64 returns the number of one bits ("population count") in x.

Prefetch prefetches data from memory addr to cache AMD64: Produce PREFETCHT0 instruction ARM64: Produce PRFM instruction with PLDL1KEEP option.

PrefetchStreamed prefetches data from memory addr, with a hint that this data is being streamed.

TrailingZeros32 returns the number of trailing zero bits in x; the result is 32 for x == 0.

TrailingZeros64 returns the number of trailing zero bits in x; the result is 64 for x == 0.

TrailingZeros8 returns the number of trailing zero bits in x; the result is 8 for x == 0.

DefaultPhysPageSize is the default physical page size.

Int64Align is the required alignment for a 64-bit integer (4 on 32-bit systems, 8 on 64-bit).

MinFrameSize is the size of the system-reserved words at the bottom of a frame (just above the architectural stack pointer).

PCQuantum is the minimal unit for a program counter (1 on x86, 4 on most other systems).

StackAlign is the required alignment of the SP register.

AIX requires a larger stack for syscalls.

NotInHeap is a type must never be allocated from the GC'd heap or on the stack, and is called not-in-heap.