// The location of each known slot, indexed by SlotID.
	slots []VarLoc
	// The slots present in each register, indexed by register number.
	registers [][]SlotID
}

// reset fills state with the live variables from live.
func (state *stateAtPC) reset(live abt.T) {
	slots, registers := state.slots, state.registers
	for i := range slots {
		slots[i] = VarLoc{}
	}
	for i := range registers {

   * number of CPUS. Table slots remain empty (null) until they are
   * needed.
   *
   * A single spinlock ("busy") is used for initializing and
   * resizing the table, as well as populating slots with new Cells.
   * There is no need for a blocking lock; when the lock is not
   * available, threads try other slots (or the base).  During these

   * number of CPUS. Table slots remain empty (null) until they are
   * needed.
   *
   * A single spinlock ("busy") is used for initializing and
   * resizing the table, as well as populating slots with new Cells.
   * There is no need for a blocking lock; when the lock is not
   * available, threads try other slots (or the base).  During these

   * number of CPUS. Table slots remain empty (null) until they are
   * needed.
   *
   * A single spinlock ("busy") is used for initializing and
   * resizing the table, as well as populating slots with new Cells.
   * There is no need for a blocking lock; when the lock is not
   * available, threads try other slots (or the base).  During these

   * number of CPUS. Table slots remain empty (null) until they are
   * needed.
   *
   * A single spinlock ("busy") is used for initializing and
   * resizing the table, as well as populating slots with new Cells.
   * There is no need for a blocking lock; when the lock is not
   * available, threads try other slots (or the base).  During these

In Go 1.23, overhead should be in the single digit percentages.

<!-- https://go.dev/issue/62737 , https://golang.org/cl/576681,  https://golang.org/cl/577615 -->
The compiler in Go 1.23 can now overlap the stack frame slots of local variables
accessed in disjoint regions of a function, which reduces stack usage
for Go applications.

<!-- https://go.dev/cl/577935 -->
For 386 and amd64, the compiler will use information from PGO to align certain

			if n.OpenDeferSlot() {
				// Open-coded defer args slots must be live
				// everywhere in a function, since a panic can
				// occur (almost) anywhere. Because it is live
				// everywhere, it must be zeroed on entry.
				livedefer.Set(int32(i))
				// It was already marked as Needzero when created.
				if !n.Needzero() {
					base.Fatalf("all pointer-containing defer arg slots should have Needzero set")
				}
			}
		}
	}

			for i := fb.cnt; i > 0; i-- {
				f := &fb.fin[i-1]

				var regs abi.RegArgs
				// The args may be passed in registers or on stack. Even for
				// the register case, we still need the spill slots.
				// TODO: revisit if we remove spill slots.
				//
				// Unfortunately because we can have an arbitrary
				// amount of returns and it would be complex to try and
				// figure out how many of those can get passed in registers,

	// of keys to make iteration order deterministic.
	Names []*LocalSlot
	// Canonicalize root/top-level local slots, and canonicalize their pieces.
	// Because LocalSlot pieces refer to their parents with a pointer, this ensures that equivalent slots really are equal.
	CanonicalLocalSlots  map[LocalSlot]*LocalSlot
	CanonicalLocalSplits map[LocalSlotSplitKey]*LocalSlot

	// does not own the mutex and competes with new arriving goroutines over
	// the ownership. New arriving goroutines have an advantage -- they are
	// already running on CPU and there can be lots of them, so a woken up
	// waiter has good chances of losing. In such case it is queued at front
	// of the wait queue. If a waiter fails to acquire the mutex for more than 1ms,
	// it switches mutex to the starvation mode.
	//