})
	}
}

type operandTest struct {
	input, output string
}

type badOperandTest struct {
	input, error string
}

// Examples collected by scanning all the assembly in the standard repo.

var amd64OperandTests = []operandTest{
	{"$(-1.0)", "$(-1.0)"},
	{"$(0.0)", "$(0.0)"},
	{"$(0x2000000+116)", "$33554548"},
	{"$(0x3F<<7)", "$8064"},
	{"$(112+8)", "$120"},

---
title: "Go, Backwards Compatibility, and GODEBUG"
layout: article
---

<!--
This document is kept in the Go repo, not x/website,
because it documents the full list of known GODEBUG settings,
which are tied to a specific release.
-->

## Introduction {#intro}

Go's emphasis on backwards compatibility is one of its key strengths.
There are, however, times when we cannot maintain complete compatibility.

			// walking the tree and copying it piecewise. If the directory tree
			// contains nested modules this could push a lot of unnecessary contents,
			// but for the golang.org/x repos it seems to be significantly (~2x)
			// faster than copying one file at a time (via filepath.WalkDir),
			// apparently due to high latency in 'adb' commands.
			if err := adb("push", modDir, deviceModDir); err != nil {