work.baseStacks = work.baseSpans + uint32(work.nSpanRoots)
	work.baseEnd = work.baseStacks + uint32(work.nStackRoots)
}

// gcMarkRootCheck checks that all roots have been scanned. It is
// purely for debugging.
func gcMarkRootCheck() {
	if work.markrootNext < work.markrootJobs {
		print(work.markrootNext, " of ", work.markrootJobs, " markroot jobs done\n")
		throw("left over markroot jobs")
	}

		panic("non-empty mark queue after concurrent mark")
	}

	if debug.gccheckmark > 0 {
		// This is expensive when there's a large number of
		// Gs, so only do it if checkmark is also enabled.
		gcMarkRootCheck()
	}

	// Drop allg snapshot. allgs may have grown, in which case
	// this is the only reference to the old backing store and
	// there's no need to keep it around.
	work.stackRoots = nil