package scan

Import Path
	internal/runtime/gc/scan (on go.dev)

Dependency Relation
	imports 5 packages, and imported by one package



Package-Level Functions (total 10)


	 func CanAVX512() bool
	
		ExpandAVX512 expands each bit in packed into f consecutive bits in unpacked,
		where f is the word size of objects in sizeClass.
		
		This is a testing entrypoint to the expanders used by scanSpanPacked*.


	
		ExpandReference is a reference implementation of an expander function
		that translates object mark bits into a bitmap of one bit per word of
		marked object, assuming the object is of the provided size class.


	
		FilterNil packs non-nil (non-zero) values in bufp together
		at the beginning of bufp, returning the length of the
		packed buffer. It treats bufp as an array of size n.


	
		FilterNilAVX512 is the simd version of FilterNil,
		it is implemented in assembly.


	 func ScanSpanPacked(mem unsafe.Pointer, bufp *uintptr, objMarks *gc.ObjMask, sizeClass uintptr, ptrMask *gc.PtrMask) (count int32)
	 func ScanSpanPackedAVX512(mem unsafe.Pointer, bufp *uintptr, objMarks *gc.ObjMask, sizeClass uintptr, ptrMask *gc.PtrMask) (count int32)
	
		ScanSpanPackedGo is an optimized pure Go implementation of ScanSpanPacked.


	
		ScanSpanPackedReference is the reference implementation of ScanScanPacked. It prioritizes clarity over performance.
		
		Concretely, ScanScanPacked functions read pointers from mem, assumed to be gc.PageSize-aligned and gc.PageSize in size,
		and writes them to bufp, which is large enough to guarantee that even if pointer-word of mem is a pointer, it will fit.
		Therefore bufp, is always at least gc.PageSize in size.
		
		ScanSpanPacked is supposed to identify pointers by first filtering words by objMarks, where each bit of the mask
		represents gc.SizeClassToSize[sizeClass] bytes of memory, and then filtering again by the bits in ptrMask.