In general, machine-specific operations tend to appear as themselves, while more general concepts like
memory move and subroutine call and return are more abstract.
The details vary with architecture, and we apologize for the imprecision; the situation is not well-defined.
</p>

<p>
The assembler program is a way to parse a description of that
semi-abstract instruction set and turn it into instructions to be

// complicated that it seems like it should be. First, we make everything "old": but
// only a few seconds old, or it might be older than gc (or the runtime source) and
// everything will get rebuilt. Then define a timestamp slightly newer than this
// time, which is what we set the mtime to of a file to cause it to be seen as new,
// and finally another slightly even newer one that we can compare files against to
// see if they have been rebuilt.

	t.Logf("%v\n%s", argv, out)
	if err != nil {
		t.Fatal(err)
	}
}

// TestCompileWithoutShared tests that if we compile code without the
// -shared option, we can put it into an archive. When we use the go
// tool with -buildmode=c-archive, it passes -shared to the compiler,
// so we override that. The go tool doesn't work this way, but Bazel
// will likely do it in the future. And it ought to work. This test

	// General address (with a few exceptions) looks like
	//	$sym±offset(SB)(reg)(index*scale)
	// Exceptions are:
	//
	//	R1
	//	offset
	//	$offset
	// Every piece is optional, so we scan left to right and what
	// we discover tells us where we are.

	// Prefix: $.
	var prefix rune
	switch tok := p.peek(); tok {
	case '$', '*':
		prefix = rune(tok)
		p.next()
	}

	// Symbol: sym±offset(SB)

	"internal/buildcfg"
	"os"
	"path/filepath"
	"regexp"
	"sort"
	"strconv"
	"strings"
	"testing"

	"cmd/asm/internal/lex"
	"cmd/internal/obj"
)

// An end-to-end test for the assembler: Do we print what we parse?
// Output is generated by, in effect, turning on -S and comparing the
// result against a golden file.

func testEndToEnd(t *testing.T, goarch, file string) {
	input := filepath.Join("testdata", file+".s")

(discussed below).

When preparing any change that is permitted by Go 1 compatibility
but may nonetheless break some existing programs,
we first engineer the change to keep as many existing programs working as possible.
For the remaining programs,
we define a new GODEBUG setting that
allows individual programs to opt back in to the old behavior.
A GODEBUG setting may not be added if doing so is infeasible,

	}
	for (i = 0; i < N; i++)
		pthread_join(tid[i], 0);
}
#endif

// issue 3261
// libgcc on ARM might be compiled as thumb code, but our 5l
// can't handle that, so we have to disable this test on arm.
#ifdef __ARMEL__
int vabs(int x) {
	puts("testLibgcc is disabled on ARM because 5l cannot handle thumb library.");
	return (x < 0) ? -x : x;
}

		// with NULs in the key.
		file: "testdata/pax-nul-xattrs.tar",
		err:  ErrHeader,
	}, {
		// BSD tar v3.1.2 rejects a PAX path with NUL in the value, while
		// GNU tar v1.27.1 simply truncates at first NUL.
		// We emulate the behavior of BSD since it is strange doing NUL
		// truncations since PAX records are length-prefix strings instead
		// of NUL-terminated C-strings.
		file: "testdata/pax-nul-path.tar",
		err:  ErrHeader,
	}, {

	next := 1

	// Next operand is the optional text flag, a literal integer.
	var flag = int64(0)
	if len(operands) == 3 {
		flag = p.evalInteger("TEXT", operands[1])
		next++
	}

	// Issue an error if we see a function defined as ABIInternal
	// without NOSPLIT. In ABIInternal, obj needs to know the function
	// signature in order to construct the morestack path, so this
	// currently isn't supported for asm functions.

		}
	}
	// Annoying aliases.
	instructions["B"] = obj.AJMP
	instructions["BL"] = obj.ACALL
	// MCR differs from MRC by the way fields of the word are encoded.
	// (Details in arm.go). Here we add the instruction so parse will find
	// it, but give it an opcode number known only to us.
	instructions["MCR"] = aMCR

	return &Arch{
		LinkArch:       &arm.Linkarm,
		Instructions:   instructions,