On Thu, Nov 24, 2022 at 3:16 PM twp...@gmail.com <twpa...@gmail.com> wrote: > > tl;dr: on 64-bit little-endian machines, does > > x := math.Float64frombits(binary.LittleEndian.Uint64(byteSlice[:8])) > > get optimized to a single move instruction from byteSlice[:8] to x? > > > Background info: > > I'm currently writing a bunch of code that unmarshals binary data. A small > example is this that unmarshals eight float64s, and a longer example is this > that unmarshals an arbitrary number of float64s. In theory, when the > endianness of the binary data matches the endianness of the architecture, > these should become simple memory copies. Does Go 1.19 do this? > > Although this is a performance question, performance is not a concern in my > use case. This is just an idle "can Go do this yet?" question and I'm curious > about the answer.
The godbolt.org website is a good way to play with this kind of question. For example https://godbolt.org/z/fasvKa3dx shows, on lines 43 and 44, that, ignoring the check that the slice bounds check, this code boils down to two instructions. Ian -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/CAOyqgcVHKbsddHx%2BM%2B2_8pYGdu1y2D%2BJGQd9dKPC%2BeM8Bc%2BM1A%40mail.gmail.com.
