the offsets being used to access them are correct.
</p>

<h2 id="architectures">Architecture-specific details</h2>

<p>
It is impractical to list all the instructions and other details for each machine.
To see what instructions are defined for a given machine, say ARM,
look in the source for the <code>obj</code> support library for
that architecture, located in the directory <code>src/cmd/internal/obj/arm</code>.

	if runtime.Compiler != "gc" {
		// The exact function names are not going to be the same.
		t.Skip("skipping for non-gc toolchain")
	}
	if runtime.GOARCH != "amd64" {
		// TODO: support SEH on other architectures.
		t.Skip("skipping on non-amd64")
	}
	// Only frames in the test package are checked.
	want := []string{
		"test._Cfunc_backtrace",
		"test.testCallbackCallersSEH.func1.1",
		"test.testCallbackCallersSEH.func1",

# Command Line

Usage:

	go tool asm [flags] file

The specified file must be a Go assembly file.
The same assembler is used for all target operating systems and architectures.
The GOOS and GOARCH environment variables set the desired target.

Flags:

	-D name[=value]
		Predefine symbol name with an optional simple value.
		Can be repeated to define multiple symbols.
	-I dir1 -I dir2

# Use of this source code is governed by a BSD-style
# license that can be found in the LICENSE file.

# Usage: buildall.bash [-e] [pattern]
#
# buildall.bash builds the standard library for all Go-supported
# architectures.
#
# Originally the Go build system used it as a smoke test to quickly
# flag portability issues in builders named "misc-compile" or "all-compile".
# As of CL 464955, the build system uses make.bash -compile-only instead,

	buildcfg.GOOS = "linux" // obj can handle this OS for all architectures.
	buildcfg.GOARCH = goarch
	architecture := arch.Set(goarch, false)
	if architecture == nil {
		panic("asm: unrecognized architecture " + goarch)
	}
	ctxt := obj.Linknew(architecture.LinkArch)
	ctxt.Pkgpath = "pkg"
	return architecture, ctxt
}

func newParser(goarch string) *Parser {
	architecture, ctxt := setArch(goarch)

	}
	c := p.peek()
	if c == ':' || c == ',' || c == '+' {
		// 2nd register; syntax (R1+R2) etc. No two architectures agree.
		// Check the architectures match the syntax.
		switch p.next().ScanToken {
		case ',':
			if !p.arch.InFamily(sys.ARM, sys.ARM64) {
				p.errorf("(register,register) not supported on this architecture")
				return
			}
		case '+':
			if p.arch.Family != sys.PPC64 {

import (
	"errors"
	"fmt"
	"internal/godebug"
	"io/fs"
	"math"
	"path"
	"reflect"
	"strconv"
	"strings"
	"time"
)

// BUG: Use of the Uid and Gid fields in Header could overflow on 32-bit
// architectures. If a large value is encountered when decoding, the result
// stored in Header will be the truncated version.

var tarinsecurepath = godebug.New("tarinsecurepath")

var (

An explicit floating-point type <a href="#Conversions">conversion</a> rounds to
the precision of the target type, preventing fusion that would discard that rounding.
</p>

<p>
For instance, some architectures provide a "fused multiply and add" (FMA) instruction
that computes <code>x*y + z</code> without rounding the intermediate result <code>x*y</code>.
These examples show when a Go implementation can use that instruction:
</p>

		tests    []errtest
	}{
		{
			allowABI: false,
			tests:    nonRuntimeTests,
		},
		{
			allowABI: true,
			tests:    runtimeTests,
		},
	}

	// Note these errors should be independent of the architecture.
	// Just run the test with amd64.
	parser := newParser("amd64")
	var buf strings.Builder
	parser.errorWriter = &buf

	for _, cat := range testcats {
		for _, test := range cat.tests {

func main() {
	log.SetFlags(0)
	log.SetPrefix("asm: ")

	buildcfg.Check()
	GOARCH := buildcfg.GOARCH

	flags.Parse()

	architecture := arch.Set(GOARCH, *flags.Shared || *flags.Dynlink)
	if architecture == nil {
		log.Fatalf("unrecognized architecture %s", GOARCH)
	}
	ctxt := obj.Linknew(architecture.LinkArch)
	ctxt.Debugasm = flags.PrintOut
	ctxt.Debugvlog = flags.DebugV
	ctxt.Flag_dynlink = *flags.Dynlink