<!--{
	"Title": "A Quick Guide to Go's Assembler",
	"Path":  "/doc/asm"
}-->

<h2 id="introduction">A Quick Guide to Go's Assembler</h2>

<p>
This document is a quick outline of the unusual form of assembly language used by the <code>gc</code> Go compiler.
The document is not comprehensive.
</p>

<p>
The assembler is based on the input style of the Plan 9 assemblers, which is documented in detail

        Model assembled = child.clone();
        assembler.assembleModelInheritance(assembled, parent, null, problems);

        // write baseName + "-actual"
        File actual = new File(
                "target/test-classes/poms/inheritance/" + baseName + (fromRepo ? "-build" : "-repo") + "-actual.xml");
        writer.write(actual, null, assembled);

// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// Package flags implements top-level flags and the usage message for the assembler.
package flags

import (
	"cmd/internal/obj"
	"cmd/internal/objabi"
	"flag"
	"fmt"
	"os"
	"path/filepath"
	"strings"
)

var (

	var ok bool
	testOut = new(strings.Builder) // The assembler writes test output to this buffer.
	ctxt.Bso = bufio.NewWriter(os.Stdout)
	ctxt.IsAsm = true
	defer ctxt.Bso.Flush()
	failed := false
	ctxt.DiagFunc = func(format string, args ...any) {
		failed = true
		t.Errorf(format, args...)
	}
	pList.Firstpc, ok = parser.Parse()
	if !ok || failed {
		t.Errorf("asm: %s assembly failed", goarch)
		return
	}

// license that can be found in the LICENSE file.

// This file encapsulates some of the odd characteristics of the RISCV64
// instruction set, to minimize its interaction with the core of the
// assembler.

package arch

import (
	"cmd/internal/obj"
	"cmd/internal/obj/riscv"
	"fmt"
)

// IsRISCV64AMO reports whether op is an AMO instruction that requires
// special handling.

// license that can be found in the LICENSE file.

// This file encapsulates some of the odd characteristics of the ARM64
// instruction set, to minimize its interaction with the core of the
// assembler.

package arch

import (
	"cmd/internal/obj"
	"cmd/internal/obj/arm64"
	"errors"
)

var arm64LS = map[string]uint8{
	"P": arm64.C_XPOST,
	"W": arm64.C_XPRE,
}

// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// Package asm implements the parser and instruction generator for the assembler.
// TODO: Split apart?
package asm

import (
	"fmt"
	"io"
	"log"
	"os"
	"strconv"
	"strings"
	"text/scanner"
	"unicode/utf8"

	"cmd/asm/internal/arch"
	"cmd/asm/internal/flags"

    "groups" : [ {
      "testProject" : "largeJavaMultiProjectNoBuildSrc",
      "coverage" : {
        "per_commit" : [ "linux" ]
      }
    } ]
  }, {
    "testId" : "org.gradle.performance.regression.java.JavaConfigurationCachePerformanceTest.assemble loading configuration cache state with hot daemon",

		p.errorf("%s: expected immediate constant; found %s", pseudo, obj.Dconv(&emptyProg, addr))
		return false
	}
	return true
}

// asmText assembles a TEXT pseudo-op.
// TEXT runtime·sigtramp(SB),4,$0-0
func (p *Parser) asmText(operands [][]lex.Token) {
	if len(operands) != 2 && len(operands) != 3 {
		p.errorf("expect two or three operands for TEXT")
		return

  "scenario" : "org.gradle.performance.regression.buildcache.TaskOutputCachingJavaPerformanceTest.clean assemble for abi change with local cache",
  "durations" : [ {
    "testProject" : "largeJavaMultiProject",
    "linux" : 1034
  } ]
}, {
  "scenario" : "org.gradle.performance.regression.buildcache.TaskOutputCachingJavaPerformanceTest.clean assemble for non-abi change with local cache",
  "durations" : [ {