go asm 源码
golang asm 代码
文件路径：/src/cmd/asm/internal/asm/asm.go
// Copyright 2014 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
import (
"bytes"
"fmt"
"strconv"
"text/scanner"
"cmd/asm/internal/arch"
"cmd/asm/internal/flags"
"cmd/asm/internal/lex"
"cmd/internal/obj"
"cmd/internal/obj/ppc64"
"cmd/internal/obj/x86"
"cmd/internal/objabi"
"cmd/internal/sys"
)
// TODO: configure the architecture
var testOut *bytes.Buffer // Gathers output when testing.
// append adds the Prog to the end of the program-thus-far.
// If doLabel is set, it also defines the labels collect for this Prog.
func (p *Parser) append(prog *obj.Prog, cond string, doLabel bool) {
if cond != "" {
switch p.arch.Family {
case sys.ARM:
if !arch.ARMConditionCodes(prog, cond) {
p.errorf("unrecognized condition code .%q", cond)
return
}
case sys.ARM64:
if !arch.ARM64Suffix(prog, cond) {
p.errorf("unrecognized suffix .%q", cond)
return
}
case sys.AMD64, sys.I386:
if err := x86.ParseSuffix(prog, cond); err != nil {
p.errorf("%v", err)
return
}
default:
p.errorf("unrecognized suffix .%q", cond)
return
}
}
if p.firstProg == nil {
p.firstProg = prog
} else {
p.lastProg.Link = prog
}
p.lastProg = prog
if doLabel {
p.pc++
for _, label := range p.pendingLabels {
if p.labels[label] != nil {
p.errorf("label %q multiply defined", label)
return
}
p.labels[label] = prog
}
p.pendingLabels = p.pendingLabels[0:0]
}
prog.Pc = p.pc
if *flags.Debug {
fmt.Println(p.lineNum, prog)
}
if testOut != nil {
fmt.Fprintln(testOut, prog)
}
}
// validSymbol checks that addr represents a valid name for a pseudo-op.
func (p *Parser) validSymbol(pseudo string, addr *obj.Addr, offsetOk bool) bool {
if addr.Sym == nil || addr.Name != obj.NAME_EXTERN && addr.Name != obj.NAME_STATIC || addr.Scale != 0 || addr.Reg != 0 {
p.errorf("%s symbol %q must be a symbol(SB)", pseudo, symbolName(addr))
return false
}
if !offsetOk && addr.Offset != 0 {
p.errorf("%s symbol %q must not be offset from SB", pseudo, symbolName(addr))
return false
}
return true
}
// evalInteger evaluates an integer constant for a pseudo-op.
func (p *Parser) evalInteger(pseudo string, operands []lex.Token) int64 {
addr := p.address(operands)
return p.getConstantPseudo(pseudo, &addr)
}
// validImmediate checks that addr represents an immediate constant.
func (p *Parser) validImmediate(pseudo string, addr *obj.Addr) bool {
if addr.Type != obj.TYPE_CONST || addr.Name != 0 || addr.Reg != 0 || addr.Index != 0 {
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
}
// Labels are function scoped. Patch existing labels and
// create a new label space for this TEXT.
p.patch()
p.labels = make(map[string]*obj.Prog)
// Operand 0 is the symbol name in the form foo(SB).
// That means symbol plus indirect on SB and no offset.
nameAddr := p.address(operands[0])
if !p.validSymbol("TEXT", &nameAddr, false) {
return
}
name := symbolName(&nameAddr)
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.
if nameAddr.Sym.ABI() == obj.ABIInternal && flag&obj.NOSPLIT == 0 {
p.errorf("TEXT %q: ABIInternal requires NOSPLIT", name)
}
// Next operand is the frame and arg size.
// Bizarre syntax: $frameSize-argSize is two words, not subtraction.
// Both frameSize and argSize must be simple integers; only frameSize
// can be negative.
// The "-argSize" may be missing; if so, set it to objabi.ArgsSizeUnknown.
// Parse left to right.
op := operands[next]
if len(op) < 2 || op[0].ScanToken != '$' {
p.errorf("TEXT %s: frame size must be an immediate constant", name)
return
}
op = op[1:]
negative := false
if op[0].ScanToken == '-' {
negative = true
op = op[1:]
}
if len(op) == 0 || op[0].ScanToken != scanner.Int {
p.errorf("TEXT %s: frame size must be an immediate constant", name)
return
}
frameSize := p.positiveAtoi(op[0].String())
if negative {
frameSize = -frameSize
}
op = op[1:]
argSize := int64(objabi.ArgsSizeUnknown)
if len(op) > 0 {
// There is an argument size. It must be a minus sign followed by a non-negative integer literal.
if len(op) != 2 || op[0].ScanToken != '-' || op[1].ScanToken != scanner.Int {
p.errorf("TEXT %s: argument size must be of form -integer", name)
return
}
argSize = p.positiveAtoi(op[1].String())
}
p.ctxt.InitTextSym(nameAddr.Sym, int(flag))
prog := &obj.Prog{
Ctxt: p.ctxt,
As: obj.ATEXT,
Pos: p.pos(),
From: nameAddr,
To: obj.Addr{
Type: obj.TYPE_TEXTSIZE,
Offset: frameSize,
// Argsize set below.
},
}
nameAddr.Sym.Func().Text = prog
prog.To.Val = int32(argSize)
p.append(prog, "", true)
}
// asmData assembles a DATA pseudo-op.
// DATA masks<>+0x00(SB)/4, $0x00000000
func (p *Parser) asmData(operands [][]lex.Token) {
if len(operands) != 2 {
p.errorf("expect two operands for DATA")
return
}
// Operand 0 has the general form foo<>+0x04(SB)/4.
op := operands[0]
n := len(op)
if n < 3 || op[n-2].ScanToken != '/' || op[n-1].ScanToken != scanner.Int {
p.errorf("expect /size for DATA argument")
return
}
szop := op[n-1].String()
sz, err := strconv.Atoi(szop)
if err != nil {
p.errorf("bad size for DATA argument: %q", szop)
}
op = op[:n-2]
nameAddr := p.address(op)
if !p.validSymbol("DATA", &nameAddr, true) {
return
}
name := symbolName(&nameAddr)
// Operand 1 is an immediate constant or address.
valueAddr := p.address(operands[1])
switch valueAddr.Type {
case obj.TYPE_CONST, obj.TYPE_FCONST, obj.TYPE_SCONST, obj.TYPE_ADDR:
// OK
default:
p.errorf("DATA value must be an immediate constant or address")
return
}
// The addresses must not overlap. Easiest test: require monotonicity.
if lastAddr, ok := p.dataAddr[name]; ok && nameAddr.Offset < lastAddr {
p.errorf("overlapping DATA entry for %s", name)
return
}
p.dataAddr[name] = nameAddr.Offset + int64(sz)
switch valueAddr.Type {
case obj.TYPE_CONST:
switch sz {
case 1, 2, 4, 8:
nameAddr.Sym.WriteInt(p.ctxt, nameAddr.Offset, int(sz), valueAddr.Offset)
default:
p.errorf("bad int size for DATA argument: %d", sz)
}
case obj.TYPE_FCONST:
switch sz {
case 4:
nameAddr.Sym.WriteFloat32(p.ctxt, nameAddr.Offset, float32(valueAddr.Val.(float64)))
case 8:
nameAddr.Sym.WriteFloat64(p.ctxt, nameAddr.Offset, valueAddr.Val.(float64))
default:
p.errorf("bad float size for DATA argument: %d", sz)
}
case obj.TYPE_SCONST:
nameAddr.Sym.WriteString(p.ctxt, nameAddr.Offset, int(sz), valueAddr.Val.(string))
case obj.TYPE_ADDR:
if sz == p.arch.PtrSize {
nameAddr.Sym.WriteAddr(p.ctxt, nameAddr.Offset, int(sz), valueAddr.Sym, valueAddr.Offset)
} else {
p.errorf("bad addr size for DATA argument: %d", sz)
}
}
}
// asmGlobl assembles a GLOBL pseudo-op.
// GLOBL shifts<>(SB),8,$256
// GLOBL shifts<>(SB),$256
func (p *Parser) asmGlobl(operands [][]lex.Token) {
if len(operands) != 2 && len(operands) != 3 {
p.errorf("expect two or three operands for GLOBL")
return
}
// Operand 0 has the general form foo<>+0x04(SB).
nameAddr := p.address(operands[0])
if !p.validSymbol("GLOBL", &nameAddr, false) {
return
}
next := 1
// Next operand is the optional flag, a literal integer.
var flag = int64(0)
if len(operands) == 3 {
flag = p.evalInteger("GLOBL", operands[1])
next++
}
// Final operand is an immediate constant.
addr := p.address(operands[next])
if !p.validImmediate("GLOBL", &addr) {
return
}
// log.Printf("GLOBL %s %d, $%d", name, flag, size)
p.ctxt.Globl(nameAddr.Sym, addr.Offset, int(flag))
}
// asmPCData assembles a PCDATA pseudo-op.
// PCDATA $2, $705
func (p *Parser) asmPCData(operands [][]lex.Token) {
if len(operands) != 2 {
p.errorf("expect two operands for PCDATA")
return
}
// Operand 0 must be an immediate constant.
key := p.address(operands[0])
if !p.validImmediate("PCDATA", &key) {
return
}
// Operand 1 must be an immediate constant.
value := p.address(operands[1])
if !p.validImmediate("PCDATA", &value) {
return
}
// log.Printf("PCDATA $%d, $%d", key.Offset, value.Offset)
prog := &obj.Prog{
Ctxt: p.ctxt,
As: obj.APCDATA,
Pos: p.pos(),
From: key,
To: value,
}
p.append(prog, "", true)
}
// asmPCAlign assembles a PCALIGN pseudo-op.
// PCALIGN $16
func (p *Parser) asmPCAlign(operands [][]lex.Token) {
if len(operands) != 1 {
p.errorf("expect one operand for PCALIGN")
return
}
// Operand 0 must be an immediate constant.
key := p.address(operands[0])
if !p.validImmediate("PCALIGN", &key) {
return
}
prog := &obj.Prog{
Ctxt: p.ctxt,
As: obj.APCALIGN,
From: key,
}
p.append(prog, "", true)
}
// asmFuncData assembles a FUNCDATA pseudo-op.
// FUNCDATA $1, funcdata<>+4(SB)
func (p *Parser) asmFuncData(operands [][]lex.Token) {
if len(operands) != 2 {
p.errorf("expect two operands for FUNCDATA")
return
}
// Operand 0 must be an immediate constant.
valueAddr := p.address(operands[0])
if !p.validImmediate("FUNCDATA", &valueAddr) {
return
}
// Operand 1 is a symbol name in the form foo(SB).
nameAddr := p.address(operands[1])
if !p.validSymbol("FUNCDATA", &nameAddr, true) {
return
}
prog := &obj.Prog{
Ctxt: p.ctxt,
As: obj.AFUNCDATA,
Pos: p.pos(),
From: valueAddr,
To: nameAddr,
}
p.append(prog, "", true)
}
// asmJump assembles a jump instruction.
// JMP R1
// JMP exit
// JMP 3(PC)
func (p *Parser) asmJump(op obj.As, cond string, a []obj.Addr) {
var target *obj.Addr
prog := &obj.Prog{
Ctxt: p.ctxt,
Pos: p.pos(),
As: op,
}
targetAddr := &prog.To
switch len(a) {
case 0:
if p.arch.Family == sys.Wasm {
target = &obj.Addr{Type: obj.TYPE_NONE}
break
}
p.errorf("wrong number of arguments to %s instruction", op)
return
case 1:
target = &a[0]
case 2:
// Special 2-operand jumps.
if p.arch.Family == sys.ARM64 && arch.IsARM64ADR(op) {
// ADR label, R. Label is in From.
target = &a[0]
prog.To = a[1]
targetAddr = &prog.From
} else {
target = &a[1]
prog.From = a[0]
}
case 3:
if p.arch.Family == sys.PPC64 {
// Special 3-operand jumps.
// a[1] is a register number expressed as a constant or register value
target = &a[2]
prog.From = a[0]
if a[0].Type != obj.TYPE_CONST {
// Legacy code may use a plain constant, accept it, and coerce
// into a constant. E.g:
// BC 4,...
// into
// BC $4,...
prog.From = obj.Addr{
Type: obj.TYPE_CONST,
Offset: p.getConstant(prog, op, &a[0]),
}
}
// Likewise, fixup usage like:
// BC x,LT,...
// BC x,foo+2,...
// BC x,4
// BC x,$5
// into
// BC x,CR0LT,...
// BC x,CR0EQ,...
// BC x,CR1LT,...
// BC x,CR1GT,...
// The first and second case demonstrate a symbol name which is
// effectively discarded. In these cases, the offset determines
// the CR bit.
prog.Reg = a[1].Reg
if a[1].Type != obj.TYPE_REG {
// The CR bit is represented as a constant 0-31. Convert it to a Reg.
c := p.getConstant(prog, op, &a[1])
reg, success := ppc64.ConstantToCRbit(c)
if !success {
p.errorf("invalid CR bit register number %d", c)
}
prog.Reg = reg
}
break
}
if p.arch.Family == sys.MIPS || p.arch.Family == sys.MIPS64 || p.arch.Family == sys.RISCV64 {
// 3-operand jumps.
// First two must be registers
target = &a[2]
prog.From = a[0]
prog.Reg = p.getRegister(prog, op, &a[1])
break
}
if p.arch.Family == sys.Loong64 {
// 3-operand jumps.
// First two must be registers
target = &a[2]
prog.From = a[0]
prog.Reg = p.getRegister(prog, op, &a[1])
break
}
if p.arch.Family == sys.S390X {
// 3-operand jumps.
target = &a[2]
prog.From = a[0]
if a[1].Reg != 0 {
// Compare two registers and jump.
prog.Reg = p.getRegister(prog, op, &a[1])
} else {
// Compare register with immediate and jump.
prog.SetFrom3(a[1])
}
break
}
if p.arch.Family == sys.ARM64 {
// Special 3-operand jumps.
// a[0] must be immediate constant; a[1] is a register.
if a[0].Type != obj.TYPE_CONST {
p.errorf("%s: expected immediate constant; found %s", op, obj.Dconv(prog, &a[0]))
return
}
prog.From = a[0]
prog.Reg = p.getRegister(prog, op, &a[1])
target = &a[2]
break
}
p.errorf("wrong number of arguments to %s instruction", op)
return
case 4:
if p.arch.Family == sys.S390X || p.arch.Family == sys.PPC64 {
// 4-operand compare-and-branch.
prog.From = a[0]
prog.Reg = p.getRegister(prog, op, &a[1])
prog.SetFrom3(a[2])
target = &a[3]
break
}
p.errorf("wrong number of arguments to %s instruction", op)
return
default:
p.errorf("wrong number of arguments to %s instruction", op)
return
}
switch {
case target.Type == obj.TYPE_BRANCH:
// JMP 4(PC)
*targetAddr = obj.Addr{
Type: obj.TYPE_BRANCH,
Offset: p.pc + 1 + target.Offset, // +1 because p.pc is incremented in append, below.
}
case target.Type == obj.TYPE_REG:
// JMP R1
*targetAddr = *target
case target.Type == obj.TYPE_MEM && (target.Name == obj.NAME_EXTERN || target.Name == obj.NAME_STATIC):
// JMP main·morestack(SB)
*targetAddr = *target
case target.Type == obj.TYPE_INDIR && (target.Name == obj.NAME_EXTERN || target.Name == obj.NAME_STATIC):
// JMP *main·morestack(SB)
*targetAddr = *target
targetAddr.Type = obj.TYPE_INDIR
case target.Type == obj.TYPE_MEM && target.Reg == 0 && target.Offset == 0:
// JMP exit
if target.Sym == nil {
// Parse error left name unset.
return
}
targetProg := p.labels[target.Sym.Name]
if targetProg == nil {
p.toPatch = append(p.toPatch, Patch{targetAddr, target.Sym.Name})
} else {
p.branch(targetAddr, targetProg)
}
case target.Type == obj.TYPE_MEM && target.Name == obj.NAME_NONE:
// JMP 4(R0)
*targetAddr = *target
// On the ppc64, 9a encodes BR (CTR) as BR CTR. We do the same.
if p.arch.Family == sys.PPC64 && target.Offset == 0 {
targetAddr.Type = obj.TYPE_REG
}
case target.Type == obj.TYPE_CONST:
// JMP $4
*targetAddr = a[0]
case target.Type == obj.TYPE_NONE:
// JMP
default:
p.errorf("cannot assemble jump %+v", target)
return
}
p.append(prog, cond, true)
}
func (p *Parser) patch() {
for _, patch := range p.toPatch {
targetProg := p.labels[patch.label]
if targetProg == nil {
p.errorf("undefined label %s", patch.label)
return
}
p.branch(patch.addr, targetProg)
}
p.toPatch = p.toPatch[:0]
}
func (p *Parser) branch(addr *obj.Addr, target *obj.Prog) {
*addr = obj.Addr{
Type: obj.TYPE_BRANCH,
Index: 0,
}
addr.Val = target
}
// asmInstruction assembles an instruction.
// MOVW R9, (R10)
func (p *Parser) asmInstruction(op obj.As, cond string, a []obj.Addr) {
// fmt.Printf("%s %+v\n", op, a)
prog := &obj.Prog{
Ctxt: p.ctxt,
Pos: p.pos(),
As: op,
}
switch len(a) {
case 0:
// Nothing to do.
case 1:
if p.arch.UnaryDst[op] || op == obj.ARET || op == obj.AGETCALLERPC {
// prog.From is no address.
prog.To = a[0]
} else {
prog.From = a[0]
// prog.To is no address.
}
if p.arch.Family == sys.PPC64 && arch.IsPPC64NEG(op) {
// NEG: From and To are both a[0].
prog.To = a[0]
prog.From = a[0]
break
}
case 2:
if p.arch.Family == sys.ARM {
if arch.IsARMCMP(op) {
prog.From = a[0]
prog.Reg = p.getRegister(prog, op, &a[1])
break
}
// Strange special cases.
if arch.IsARMFloatCmp(op) {
prog.From = a[0]
prog.Reg = p.getRegister(prog, op, &a[1])
break
}
} else if p.arch.Family == sys.ARM64 && arch.IsARM64CMP(op) {
prog.From = a[0]
prog.Reg = p.getRegister(prog, op, &a[1])
break
} else if p.arch.Family == sys.MIPS || p.arch.Family == sys.MIPS64 {
if arch.IsMIPSCMP(op) || arch.IsMIPSMUL(op) {
prog.From = a[0]
prog.Reg = p.getRegister(prog, op, &a[1])
break
}
} else if p.arch.Family == sys.Loong64 {
if arch.IsLoong64CMP(op) {
prog.From = a[0]
prog.Reg = p.getRegister(prog, op, &a[1])
break
}
}
prog.From = a[0]
prog.To = a[1]
case 3:
switch p.arch.Family {
case sys.MIPS, sys.MIPS64:
prog.From = a[0]
prog.Reg = p.getRegister(prog, op, &a[1])
prog.To = a[2]
case sys.Loong64:
prog.From = a[0]
prog.Reg = p.getRegister(prog, op, &a[1])
prog.To = a[2]
case sys.ARM:
// Special cases.
if arch.IsARMSTREX(op) {
/*
STREX x, (y), z
from=(y) reg=x to=z
*/
prog.From = a[1]
prog.Reg = p.getRegister(prog, op, &a[0])
prog.To = a[2]
break
}
if arch.IsARMBFX(op) {
// a[0] and a[1] must be constants, a[2] must be a register
prog.From = a[0]
prog.SetFrom3(a[1])
prog.To = a[2]
break
}
// Otherwise the 2nd operand (a[1]) must be a register.
prog.From = a[0]
prog.Reg = p.getRegister(prog, op, &a[1])
prog.To = a[2]
case sys.AMD64:
prog.From = a[0]
prog.SetFrom3(a[1])
prog.To = a[2]
case sys.ARM64:
switch {
case arch.IsARM64STLXR(op):
// ARM64 instructions with one input and two outputs.
prog.From = a[0]
prog.To = a[1]
if a[2].Type != obj.TYPE_REG {
p.errorf("invalid addressing modes for third operand to %s instruction, must be register", op)
return
}
prog.RegTo2 = a[2].Reg
case arch.IsARM64TBL(op):
// one of its inputs does not fit into prog.Reg.
prog.From = a[0]
prog.SetFrom3(a[1])
prog.To = a[2]
case arch.IsARM64CASP(op):
prog.From = a[0]
prog.To = a[1]
// both 1st operand and 3rd operand are (Rs, Rs+1) register pair.
// And the register pair must be contiguous.
if (a[0].Type != obj.TYPE_REGREG) || (a[2].Type != obj.TYPE_REGREG) {
p.errorf("invalid addressing modes for 1st or 3rd operand to %s instruction, must be register pair", op)
return
}
// For ARM64 CASP-like instructions, its 2nd destination operand is register pair(Rt, Rt+1) that can
// not fit into prog.RegTo2, so save it to the prog.RestArgs.
prog.SetTo2(a[2])
default:
prog.From = a[0]
prog.Reg = p.getRegister(prog, op, &a[1])
prog.To = a[2]
}
case sys.I386:
prog.From = a[0]
prog.SetFrom3(a[1])
prog.To = a[2]
case sys.PPC64:
if arch.IsPPC64CMP(op) {
// CMPW etc.; third argument is a CR register that goes into prog.Reg.
prog.From = a[0]
prog.Reg = p.getRegister(prog, op, &a[2])
prog.To = a[1]
break
}
// Arithmetic. Choices are:
// reg reg reg
// imm reg reg
// reg imm reg
// If the immediate is the middle argument, use From3.
switch a[1].Type {
case obj.TYPE_REG:
prog.From = a[0]
prog.Reg = p.getRegister(prog, op, &a[1])
prog.To = a[2]
case obj.TYPE_CONST:
prog.From = a[0]
prog.SetFrom3(a[1])
prog.To = a[2]
default:
p.errorf("invalid addressing modes for %s instruction", op)
return
}
case sys.RISCV64:
// RISCV64 instructions with one input and two outputs.
if arch.IsRISCV64AMO(op) {
prog.From = a[0]
prog.To = a[1]
if a[2].Type != obj.TYPE_REG {
p.errorf("invalid addressing modes for third operand to %s instruction, must be register", op)
return
}
prog.RegTo2 = a[2].Reg
break
}
prog.From = a[0]
prog.Reg = p.getRegister(prog, op, &a[1])
prog.To = a[2]
case sys.S390X:
prog.From = a[0]
if a[1].Type == obj.TYPE_REG {
prog.Reg = p.getRegister(prog, op, &a[1])
} else {
prog.SetFrom3(a[1])
}
prog.To = a[2]
default:
p.errorf("TODO: implement three-operand instructions for this architecture")
return
}
case 4:
if p.arch.Family == sys.ARM {
if arch.IsARMBFX(op) {
// a[0] and a[1] must be constants, a[2] and a[3] must be registers
prog.From = a[0]
prog.SetFrom3(a[1])
prog.Reg = p.getRegister(prog, op, &a[2])
prog.To = a[3]
break
}
if arch.IsARMMULA(op) {
// All must be registers.
p.getRegister(prog, op, &a[0])
r1 := p.getRegister(prog, op, &a[1])
r2 := p.getRegister(prog, op, &a[2])
p.getRegister(prog, op, &a[3])
prog.From = a[0]
prog.To = a[3]
prog.To.Type = obj.TYPE_REGREG2
prog.To.Offset = int64(r2)
prog.Reg = r1
break
}
}
if p.arch.Family == sys.AMD64 {
prog.From = a[0]
prog.SetRestArgs([]obj.Addr{a[1], a[2]})
prog.To = a[3]
break
}
if p.arch.Family == sys.ARM64 {
prog.From = a[0]
prog.Reg = p.getRegister(prog, op, &a[1])
prog.SetFrom3(a[2])
prog.To = a[3]
break
}
if p.arch.Family == sys.PPC64 {
if arch.IsPPC64RLD(op) {
prog.From = a[0]
prog.Reg = p.getRegister(prog, op, &a[1])
prog.SetFrom3(a[2])
prog.To = a[3]
break
} else if arch.IsPPC64ISEL(op) {
// ISEL BC,RB,RA,RT becomes isel rt,ra,rb,bc
prog.SetFrom3(a[2]) // ra
prog.From = a[0] // bc
prog.Reg = p.getRegister(prog, op, &a[1]) // rb
prog.To = a[3] // rt
break
}
// Else, it is a VA-form instruction
// reg reg reg reg
// imm reg reg reg
// Or a VX-form instruction
// imm imm reg reg
if a[1].Type == obj.TYPE_REG {
prog.From = a[0]
prog.Reg = p.getRegister(prog, op, &a[1])
prog.SetFrom3(a[2])
prog.To = a[3]
break
} else if a[1].Type == obj.TYPE_CONST {
prog.From = a[0]
prog.Reg = p.getRegister(prog, op, &a[2])
prog.SetFrom3(a[1])
prog.To = a[3]
break
} else {
p.errorf("invalid addressing modes for %s instruction", op)
return
}
}
if p.arch.Family == sys.RISCV64 {
prog.From = a[0]
prog.Reg = p.getRegister(prog, op, &a[1])
prog.SetRestArgs([]obj.Addr{a[2]})
prog.To = a[3]
break
}
if p.arch.Family == sys.S390X {
if a[1].Type != obj.TYPE_REG {
p.errorf("second operand must be a register in %s instruction", op)
return
}
prog.From = a[0]
prog.Reg = p.getRegister(prog, op, &a[1])
prog.SetFrom3(a[2])
prog.To = a[3]
break
}
p.errorf("can't handle %s instruction with 4 operands", op)
return
case 5:
if p.arch.Family == sys.PPC64 {
prog.From = a[0]
// Second arg is always a register type on ppc64.
prog.Reg = p.getRegister(prog, op, &a[1])
prog.SetRestArgs([]obj.Addr{a[2], a[3]})
prog.To = a[4]
break
}
if p.arch.Family == sys.AMD64 {
prog.From = a[0]
prog.SetRestArgs([]obj.Addr{a[1], a[2], a[3]})
prog.To = a[4]
break
}
if p.arch.Family == sys.S390X {
prog.From = a[0]
prog.SetRestArgs([]obj.Addr{a[1], a[2], a[3]})
prog.To = a[4]
break
}
p.errorf("can't handle %s instruction with 5 operands", op)
return
case 6:
if p.arch.Family == sys.ARM && arch.IsARMMRC(op) {
// Strange special case: MCR, MRC.
prog.To.Type = obj.TYPE_CONST
x0 := p.getConstant(prog, op, &a[0])
x1 := p.getConstant(prog, op, &a[1])
x2 := int64(p.getRegister(prog, op, &a[2]))
x3 := int64(p.getRegister(prog, op, &a[3]))
x4 := int64(p.getRegister(prog, op, &a[4]))
x5 := p.getConstant(prog, op, &a[5])
// Cond is handled specially for this instruction.
offset, MRC, ok := arch.ARMMRCOffset(op, cond, x0, x1, x2, x3, x4, x5)
if !ok {
p.errorf("unrecognized condition code .%q", cond)
}
prog.To.Offset = offset
cond = ""
prog.As = MRC // Both instructions are coded as MRC.
break
}
fallthrough
default:
p.errorf("can't handle %s instruction with %d operands", op, len(a))
return
}
p.append(prog, cond, true)
}
// newAddr returns a new(Addr) initialized to x.
func newAddr(x obj.Addr) *obj.Addr {
p := new(obj.Addr)
*p = x
return p
}
// symbolName returns the symbol name, or an error string if none if available.
func symbolName(addr *obj.Addr) string {
if addr.Sym != nil {
return addr.Sym.Name
}
return "<erroneous symbol>"
}
var emptyProg obj.Prog
// getConstantPseudo checks that addr represents a plain constant and returns its value.
func (p *Parser) getConstantPseudo(pseudo string, addr *obj.Addr) int64 {
if addr.Type != obj.TYPE_MEM || addr.Name != 0 || addr.Reg != 0 || addr.Index != 0 {
p.errorf("%s: expected integer constant; found %s", pseudo, obj.Dconv(&emptyProg, addr))
}
return addr.Offset
}
// getConstant checks that addr represents a plain constant and returns its value.
func (p *Parser) getConstant(prog *obj.Prog, op obj.As, addr *obj.Addr) int64 {
if addr.Type != obj.TYPE_MEM || addr.Name != 0 || addr.Reg != 0 || addr.Index != 0 {
p.errorf("%s: expected integer constant; found %s", op, obj.Dconv(prog, addr))
}
return addr.Offset
}
// getImmediate checks that addr represents an immediate constant and returns its value.
func (p *Parser) getImmediate(prog *obj.Prog, op obj.As, addr *obj.Addr) int64 {
if addr.Type != obj.TYPE_CONST || addr.Name != 0 || addr.Reg != 0 || addr.Index != 0 {
p.errorf("%s: expected immediate constant; found %s", op, obj.Dconv(prog, addr))
}
return addr.Offset
}
// getRegister checks that addr represents a register and returns its value.
func (p *Parser) getRegister(prog *obj.Prog, op obj.As, addr *obj.Addr) int16 {
if addr.Type != obj.TYPE_REG || addr.Offset != 0 || addr.Name != 0 || addr.Index != 0 {
p.errorf("%s: expected register; found %s", op, obj.Dconv(prog, addr))
}
return addr.Reg
}
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