Data: unsafe.Pointer(&s[0]),
		Len:  int((uintptr(len(s)) + scale - 1) / scale),
		Cap:  int((uintptr(cap(s)) + scale - 1) / scale),
	}
	c.freeInt64Slice(*(*[]int64)(unsafe.Pointer(&b)))
}
func (c *Cache) allocIDSlice(n int) []ID {
	var base int64
	var derived ID
	if unsafe.Sizeof(base)%unsafe.Sizeof(derived) != 0 {
		panic("bad")
	}
	scale := unsafe.Sizeof(base) / unsafe.Sizeof(derived)

	// Adapted directly from the original TOPLAS article's "simple" algorithm

	maxBlockID := entry.Func.NumBlocks()
	scratch := f.Cache.allocIDSlice(7 * maxBlockID)
	defer f.Cache.freeIDSlice(scratch)
	semi := scratch[0*maxBlockID : 1*maxBlockID]
	vertex := scratch[1*maxBlockID : 2*maxBlockID]
	label := scratch[2*maxBlockID : 3*maxBlockID]

				f.auxmap[v.Aux] = int32(len(f.auxmap)) + 1
			}
			a = append(a, v)
		}
	}
	partition := partitionValues(a, f.auxmap)

	// map from value id back to eqclass id
	valueEqClass := f.Cache.allocIDSlice(f.NumValues())
	defer f.Cache.freeIDSlice(valueEqClass)
	for _, b := range f.Blocks {
		for _, v := range b.Values {
			// Use negative equivalence class #s for unique values.
			valueEqClass[v.ID] = -v.ID
		}
	}