func (p *exporter) value(x exact.Value) {
if trace {
p.tracef("value { ")
defer p.tracef("} ")
}
switch kind := x.Kind(); kind {
case exact.Bool:
tag := falseTag
if exact.BoolVal(x) {
tag = trueTag
}
p.int(tag)
case exact.Int:
if i, ok := exact.Int64Val(x); ok {
p.int(int64Tag)
p.int64(i)
return
}
p.int(floatTag)
p.float(x)
case exact.Float:
p.int(fractionTag)
p.fraction(x)
case exact.Complex:
p.int(complexTag)
p.fraction(exact.Real(x))
p.fraction(exact.Imag(x))
case exact.String:
p.int(stringTag)
p.string(exact.StringVal(x))
default:
panic(fmt.Sprintf("unexpected value kind %d", kind))
}
}
// representableConst reports whether x can be represented as
// value of the given basic type kind and for the configuration
// provided (only needed for int/uint sizes).
//
// If rounded != nil, *rounded is set to the rounded value of x for
// representable floating-point values; it is left alone otherwise.
// It is ok to provide the addressof the first argument for rounded.
func representableConst(x exact.Value, conf *Config, as BasicKind, rounded *exact.Value) bool {
switch x.Kind() {
case exact.Unknown:
return true
case exact.Bool:
return as == Bool || as == UntypedBool
case exact.Int:
if x, ok := exact.Int64Val(x); ok {
switch as {
case Int:
var s = uint(conf.sizeof(Typ[as])) * 8
return int64(-1)<<(s-1) <= x && x <= int64(1)<<(s-1)-1
case Int8:
const s = 8
return -1<<(s-1) <= x && x <= 1<<(s-1)-1
case Int16:
const s = 16
return -1<<(s-1) <= x && x <= 1<<(s-1)-1
case Int32:
const s = 32
return -1<<(s-1) <= x && x <= 1<<(s-1)-1
case Int64:
return true
case Uint, Uintptr:
if s := uint(conf.sizeof(Typ[as])) * 8; s < 64 {
return 0 <= x && x <= int64(1)<<s-1
}
return 0 <= x
case Uint8:
const s = 8
return 0 <= x && x <= 1<<s-1
case Uint16:
const s = 16
return 0 <= x && x <= 1<<s-1
case Uint32:
const s = 32
return 0 <= x && x <= 1<<s-1
case Uint64:
return 0 <= x
case Float32, Float64, Complex64, Complex128,
UntypedInt, UntypedFloat, UntypedComplex:
return true
}
}
n := exact.BitLen(x)
switch as {
case Uint, Uintptr:
var s = uint(conf.sizeof(Typ[as])) * 8
return exact.Sign(x) >= 0 && n <= int(s)
case Uint64:
return exact.Sign(x) >= 0 && n <= 64
case Float32, Complex64:
if rounded == nil {
return fitsFloat32(x)
}
r := roundFloat32(x)
if r != nil {
*rounded = r
return true
}
case Float64, Complex128:
if rounded == nil {
return fitsFloat64(x)
}
r := roundFloat64(x)
if r != nil {
*rounded = r
return true
}
case UntypedInt, UntypedFloat, UntypedComplex:
return true
}
case exact.Float:
switch as {
case Float32, Complex64:
if rounded == nil {
return fitsFloat32(x)
}
r := roundFloat32(x)
if r != nil {
*rounded = r
return true
}
case Float64, Complex128:
if rounded == nil {
return fitsFloat64(x)
}
r := roundFloat64(x)
if r != nil {
*rounded = r
return true
}
case UntypedFloat, UntypedComplex:
return true
}
case exact.Complex:
switch as {
case Complex64:
if rounded == nil {
return fitsFloat32(exact.Real(x)) && fitsFloat32(exact.Imag(x))
}
re := roundFloat32(exact.Real(x))
im := roundFloat32(exact.Imag(x))
if re != nil && im != nil {
*rounded = exact.BinaryOp(re, token.ADD, exact.MakeImag(im))
return true
}
case Complex128:
if rounded == nil {
return fitsFloat64(exact.Real(x)) && fitsFloat64(exact.Imag(x))
}
re := roundFloat64(exact.Real(x))
im := roundFloat64(exact.Imag(x))
if re != nil && im != nil {
*rounded = exact.BinaryOp(re, token.ADD, exact.MakeImag(im))
return true
}
case UntypedComplex:
return true
}
case exact.String:
return as == String || as == UntypedString
default:
unreachable()
}
return false
}
// newValueFromConst converts a constant value to an LLVM value.
func (fr *frame) newValueFromConst(v exact.Value, typ types.Type) *govalue {
switch {
case v == nil:
llvmtyp := fr.types.ToLLVM(typ)
return newValue(llvm.ConstNull(llvmtyp), typ)
case isString(typ):
if isUntyped(typ) {
typ = types.Typ[types.String]
}
llvmtyp := fr.types.ToLLVM(typ)
strval := exact.StringVal(v)
strlen := len(strval)
i8ptr := llvm.PointerType(llvm.Int8Type(), 0)
var ptr llvm.Value
if strlen > 0 {
init := llvm.ConstString(strval, false)
ptr = llvm.AddGlobal(fr.module.Module, init.Type(), "")
ptr.SetInitializer(init)
ptr.SetLinkage(llvm.InternalLinkage)
ptr = llvm.ConstBitCast(ptr, i8ptr)
} else {
ptr = llvm.ConstNull(i8ptr)
}
len_ := llvm.ConstInt(fr.types.inttype, uint64(strlen), false)
llvmvalue := llvm.Undef(llvmtyp)
llvmvalue = llvm.ConstInsertValue(llvmvalue, ptr, []uint32{0})
llvmvalue = llvm.ConstInsertValue(llvmvalue, len_, []uint32{1})
return newValue(llvmvalue, typ)
case isInteger(typ):
if isUntyped(typ) {
typ = types.Typ[types.Int]
}
llvmtyp := fr.types.ToLLVM(typ)
var llvmvalue llvm.Value
if isUnsigned(typ) {
v, _ := exact.Uint64Val(v)
llvmvalue = llvm.ConstInt(llvmtyp, v, false)
} else {
v, _ := exact.Int64Val(v)
llvmvalue = llvm.ConstInt(llvmtyp, uint64(v), true)
}
return newValue(llvmvalue, typ)
case isBoolean(typ):
if isUntyped(typ) {
typ = types.Typ[types.Bool]
}
return newValue(boolLLVMValue(exact.BoolVal(v)), typ)
case isFloat(typ):
if isUntyped(typ) {
typ = types.Typ[types.Float64]
}
llvmtyp := fr.types.ToLLVM(typ)
floatval, _ := exact.Float64Val(v)
llvmvalue := llvm.ConstFloat(llvmtyp, floatval)
return newValue(llvmvalue, typ)
case typ == types.Typ[types.UnsafePointer]:
llvmtyp := fr.types.ToLLVM(typ)
v, _ := exact.Uint64Val(v)
llvmvalue := llvm.ConstInt(fr.types.inttype, v, false)
llvmvalue = llvm.ConstIntToPtr(llvmvalue, llvmtyp)
return newValue(llvmvalue, typ)
case isComplex(typ):
if isUntyped(typ) {
typ = types.Typ[types.Complex128]
}
llvmtyp := fr.types.ToLLVM(typ)
floattyp := llvmtyp.StructElementTypes()[0]
llvmvalue := llvm.ConstNull(llvmtyp)
realv := exact.Real(v)
imagv := exact.Imag(v)
realfloatval, _ := exact.Float64Val(realv)
imagfloatval, _ := exact.Float64Val(imagv)
llvmre := llvm.ConstFloat(floattyp, realfloatval)
llvmim := llvm.ConstFloat(floattyp, imagfloatval)
llvmvalue = llvm.ConstInsertValue(llvmvalue, llvmre, []uint32{0})
llvmvalue = llvm.ConstInsertValue(llvmvalue, llvmim, []uint32{1})
return newValue(llvmvalue, typ)
}
// Special case for string -> [](byte|rune)
if u, ok := typ.Underlying().(*types.Slice); ok && isInteger(u.Elem()) {
if v.Kind() == exact.String {
strval := fr.newValueFromConst(v, types.Typ[types.String])
return fr.convert(strval, typ)
}
}
panic(fmt.Sprintf("unhandled: t=%s(%T), v=%v(%T)", typ, typ, v, v))
}