in go/analysis/passes/asmdecl/asmdecl.go [638:823]
func asmCheckVar(badf func(string, ...interface{}), fn *asmFunc, line, expr string, off int, v *asmVar, archDef *asmArch) {
m := asmOpcode.FindStringSubmatch(line)
if m == nil {
if !strings.HasPrefix(strings.TrimSpace(line), "//") {
badf("cannot find assembly opcode")
}
return
}
addr := strings.HasPrefix(expr, "$")
// Determine operand sizes from instruction.
// Typically the suffix suffices, but there are exceptions.
var src, dst, kind asmKind
op := m[1]
switch fn.arch.name + "." + op {
case "386.FMOVLP":
src, dst = 8, 4
case "arm.MOVD":
src = 8
case "arm.MOVW":
src = 4
case "arm.MOVH", "arm.MOVHU":
src = 2
case "arm.MOVB", "arm.MOVBU":
src = 1
// LEA* opcodes don't really read the second arg.
// They just take the address of it.
case "386.LEAL":
dst = 4
addr = true
case "amd64.LEAQ":
dst = 8
addr = true
default:
switch fn.arch.name {
case "386", "amd64":
if strings.HasPrefix(op, "F") && (strings.HasSuffix(op, "D") || strings.HasSuffix(op, "DP")) {
// FMOVDP, FXCHD, etc
src = 8
break
}
if strings.HasPrefix(op, "P") && strings.HasSuffix(op, "RD") {
// PINSRD, PEXTRD, etc
src = 4
break
}
if strings.HasPrefix(op, "F") && (strings.HasSuffix(op, "F") || strings.HasSuffix(op, "FP")) {
// FMOVFP, FXCHF, etc
src = 4
break
}
if strings.HasSuffix(op, "SD") {
// MOVSD, SQRTSD, etc
src = 8
break
}
if strings.HasSuffix(op, "SS") {
// MOVSS, SQRTSS, etc
src = 4
break
}
if op == "MOVO" || op == "MOVOU" {
src = 16
break
}
if strings.HasPrefix(op, "SET") {
// SETEQ, etc
src = 1
break
}
switch op[len(op)-1] {
case 'B':
src = 1
case 'W':
src = 2
case 'L':
src = 4
case 'D', 'Q':
src = 8
}
case "ppc64", "ppc64le":
// Strip standard suffixes to reveal size letter.
m := ppc64Suff.FindStringSubmatch(op)
if m != nil {
switch m[1][0] {
case 'B':
src = 1
case 'H':
src = 2
case 'W':
src = 4
case 'D':
src = 8
}
}
case "mips", "mipsle", "mips64", "mips64le":
switch op {
case "MOVB", "MOVBU":
src = 1
case "MOVH", "MOVHU":
src = 2
case "MOVW", "MOVWU", "MOVF":
src = 4
case "MOVV", "MOVD":
src = 8
}
case "s390x":
switch op {
case "MOVB", "MOVBZ":
src = 1
case "MOVH", "MOVHZ":
src = 2
case "MOVW", "MOVWZ", "FMOVS":
src = 4
case "MOVD", "FMOVD":
src = 8
}
}
}
if dst == 0 {
dst = src
}
// Determine whether the match we're holding
// is the first or second argument.
if strings.Index(line, expr) > strings.Index(line, ",") {
kind = dst
} else {
kind = src
}
vk := v.kind
vs := v.size
vt := v.typ
switch vk {
case asmInterface, asmEmptyInterface, asmString, asmSlice:
// allow reference to first word (pointer)
vk = v.inner[0].kind
vs = v.inner[0].size
vt = v.inner[0].typ
case asmComplex:
// Allow a single instruction to load both parts of a complex.
if int(kind) == vs {
kind = asmComplex
}
}
if addr {
vk = asmKind(archDef.ptrSize)
vs = archDef.ptrSize
vt = "address"
}
if off != v.off {
var inner bytes.Buffer
for i, vi := range v.inner {
if len(v.inner) > 1 {
fmt.Fprintf(&inner, ",")
}
fmt.Fprintf(&inner, " ")
if i == len(v.inner)-1 {
fmt.Fprintf(&inner, "or ")
}
fmt.Fprintf(&inner, "%s+%d(FP)", vi.name, vi.off)
}
badf("invalid offset %s; expected %s+%d(FP)%s", expr, v.name, v.off, inner.String())
return
}
if kind != 0 && kind != vk {
var inner bytes.Buffer
if len(v.inner) > 0 {
fmt.Fprintf(&inner, " containing")
for i, vi := range v.inner {
if i > 0 && len(v.inner) > 2 {
fmt.Fprintf(&inner, ",")
}
fmt.Fprintf(&inner, " ")
if i > 0 && i == len(v.inner)-1 {
fmt.Fprintf(&inner, "and ")
}
fmt.Fprintf(&inner, "%s+%d(FP)", vi.name, vi.off)
}
}
badf("invalid %s of %s; %s is %d-byte value%s", op, expr, vt, vs, inner.String())
}
}