// stringIterNext advances the iterator, and returns the tuple (ok, k, v).
func (c *compiler) stringIterNext(str *LLVMValue, preds []llvm.BasicBlock) *LLVMValue {
// While Range/Next expresses a mutating operation, we represent them using
// a Phi node where the first incoming branch (before the loop), and all
// others take the previous value plus one.
//
// See ssa.go for comments on (and assertions of) our assumptions.
index := c.builder.CreatePHI(c.types.inttype, "index")
strnext := c.runtime.strnext.LLVMValue()
args := []llvm.Value{
c.coerceString(str.LLVMValue(), strnext.Type().ElementType().ParamTypes()[0]),
index,
}
result := c.builder.CreateCall(strnext, args, "")
nextindex := c.builder.CreateExtractValue(result, 0, "")
runeval := c.builder.CreateExtractValue(result, 1, "")
values := make([]llvm.Value, len(preds))
values[0] = llvm.ConstNull(index.Type())
for i, _ := range preds[1:] {
values[i+1] = nextindex
}
index.AddIncoming(values, preds)
// Create an (ok, index, rune) tuple.
ok := c.builder.CreateIsNotNull(nextindex, "")
typ := tupleType(types.Typ[types.Bool], types.Typ[types.Int], types.Typ[types.Rune])
tuple := llvm.Undef(c.types.ToLLVM(typ))
tuple = c.builder.CreateInsertValue(tuple, ok, 0, "")
tuple = c.builder.CreateInsertValue(tuple, index, 1, "")
tuple = c.builder.CreateInsertValue(tuple, runeval, 2, "")
return c.NewValue(tuple, typ)
}
func (c *compiler) makeInterface(v *LLVMValue, iface types.Type) *LLVMValue {
llv := v.LLVMValue()
lltyp := llv.Type()
i8ptr := llvm.PointerType(llvm.Int8Type(), 0)
if lltyp.TypeKind() == llvm.PointerTypeKind {
llv = c.builder.CreateBitCast(llv, i8ptr, "")
} else {
// If the value fits exactly in a pointer, then we can just
// bitcast it. Otherwise we need to malloc.
if c.target.TypeStoreSize(lltyp) <= uint64(c.target.PointerSize()) {
bits := c.target.TypeSizeInBits(lltyp)
if bits > 0 {
llv = coerce(c.builder, llv, llvm.IntType(int(bits)))
llv = c.builder.CreateIntToPtr(llv, i8ptr, "")
} else {
llv = llvm.ConstNull(i8ptr)
}
} else {
ptr := c.createTypeMalloc(lltyp)
c.builder.CreateStore(llv, ptr)
llv = c.builder.CreateBitCast(ptr, i8ptr, "")
}
}
value := llvm.Undef(c.types.ToLLVM(iface))
rtype := c.types.ToRuntime(v.Type())
rtype = c.builder.CreateBitCast(rtype, llvm.PointerType(llvm.Int8Type(), 0), "")
value = c.builder.CreateInsertValue(value, rtype, 0, "")
value = c.builder.CreateInsertValue(value, llv, 1, "")
if iface.Underlying().(*types.Interface).NumMethods() > 0 {
result := c.NewValue(value, types.NewInterface(nil, nil))
result, _ = result.convertE2I(iface)
return result
}
return c.NewValue(value, iface)
}
// interfaceMethod returns a function pointer for the specified
// interface and method pair.
func (c *compiler) interfaceMethod(iface *LLVMValue, method *types.Func) *LLVMValue {
lliface := iface.LLVMValue()
llitab := c.builder.CreateExtractValue(lliface, 0, "")
llvalue := c.builder.CreateExtractValue(lliface, 1, "")
sig := method.Type().(*types.Signature)
methodset := c.types.MethodSet(sig.Recv().Type())
// TODO(axw) cache ordered method index
var index int
for i := 0; i < methodset.Len(); i++ {
if methodset.At(i).Obj() == method {
index = i
break
}
}
llitab = c.builder.CreateBitCast(llitab, llvm.PointerType(c.runtime.itab.llvm, 0), "")
llifn := c.builder.CreateGEP(llitab, []llvm.Value{
llvm.ConstInt(llvm.Int32Type(), 0, false),
llvm.ConstInt(llvm.Int32Type(), 5, false), // index of itab.fun
}, "")
_ = index
llifn = c.builder.CreateGEP(llifn, []llvm.Value{
llvm.ConstInt(llvm.Int32Type(), uint64(index), false),
}, "")
llifn = c.builder.CreateLoad(llifn, "")
// Strip receiver.
sig = types.NewSignature(nil, nil, sig.Params(), sig.Results(), sig.Variadic())
llfn := llvm.Undef(c.types.ToLLVM(sig))
llifn = c.builder.CreateIntToPtr(llifn, llfn.Type().StructElementTypes()[0], "")
llfn = c.builder.CreateInsertValue(llfn, llifn, 0, "")
llfn = c.builder.CreateInsertValue(llfn, llvalue, 1, "")
return c.NewValue(llfn, sig)
}
// mapLookup implements v[, ok] = m[k]
func (c *compiler) mapLookup(m, k *LLVMValue, commaOk bool) *LLVMValue {
dyntyp := c.types.ToRuntime(m.Type())
dyntyp = c.builder.CreatePtrToInt(dyntyp, c.target.IntPtrType(), "")
stackptr := c.stacksave()
llk := k.LLVMValue()
pk := c.builder.CreateAlloca(llk.Type(), "")
c.builder.CreateStore(llk, pk)
elemtyp := m.Type().Underlying().(*types.Map).Elem()
pv := c.builder.CreateAlloca(c.types.ToLLVM(elemtyp), "")
ok := c.builder.CreateCall(
c.runtime.mapaccess.LLVMValue(),
[]llvm.Value{
dyntyp,
m.LLVMValue(),
c.builder.CreatePtrToInt(pk, c.target.IntPtrType(), ""),
c.builder.CreatePtrToInt(pv, c.target.IntPtrType(), ""),
}, "",
)
v := c.builder.CreateLoad(pv, "")
c.stackrestore(stackptr)
if !commaOk {
return c.NewValue(v, elemtyp)
}
typ := tupleType(elemtyp, types.Typ[types.Bool])
tuple := llvm.Undef(c.types.ToLLVM(typ))
tuple = c.builder.CreateInsertValue(tuple, v, 0, "")
tuple = c.builder.CreateInsertValue(tuple, ok, 1, "")
return c.NewValue(tuple, typ)
}
func (c *compiler) slice(x, low, high *LLVMValue) *LLVMValue {
if low != nil {
low = low.Convert(types.Typ[types.Int]).(*LLVMValue)
} else {
low = c.NewValue(llvm.ConstNull(c.types.inttype), types.Typ[types.Int])
}
if high != nil {
high = high.Convert(types.Typ[types.Int]).(*LLVMValue)
} else {
// all bits set is -1
high = c.NewValue(llvm.ConstAllOnes(c.types.inttype), types.Typ[types.Int])
}
switch typ := x.Type().Underlying().(type) {
case *types.Pointer: // *array
sliceslice := c.runtime.sliceslice.LLVMValue()
i8slice := sliceslice.Type().ElementType().ReturnType()
sliceValue := llvm.Undef(i8slice) // temporary slice
arraytyp := typ.Elem().Underlying().(*types.Array)
arrayptr := x.LLVMValue()
arrayptr = c.builder.CreateBitCast(arrayptr, i8slice.StructElementTypes()[0], "")
arraylen := llvm.ConstInt(c.llvmtypes.inttype, uint64(arraytyp.Len()), false)
sliceValue = c.builder.CreateInsertValue(sliceValue, arrayptr, 0, "")
sliceValue = c.builder.CreateInsertValue(sliceValue, arraylen, 1, "")
sliceValue = c.builder.CreateInsertValue(sliceValue, arraylen, 2, "")
sliceTyp := types.NewSlice(arraytyp.Elem())
runtimeTyp := c.types.ToRuntime(sliceTyp)
runtimeTyp = c.builder.CreatePtrToInt(runtimeTyp, c.target.IntPtrType(), "")
args := []llvm.Value{runtimeTyp, sliceValue, low.LLVMValue(), high.LLVMValue()}
result := c.builder.CreateCall(sliceslice, args, "")
llvmSliceTyp := c.types.ToLLVM(sliceTyp)
return c.NewValue(c.coerceSlice(result, llvmSliceTyp), sliceTyp)
case *types.Slice:
sliceslice := c.runtime.sliceslice.LLVMValue()
i8slice := sliceslice.Type().ElementType().ReturnType()
sliceValue := x.LLVMValue()
sliceTyp := sliceValue.Type()
sliceValue = c.coerceSlice(sliceValue, i8slice)
runtimeTyp := c.types.ToRuntime(x.Type())
runtimeTyp = c.builder.CreatePtrToInt(runtimeTyp, c.target.IntPtrType(), "")
args := []llvm.Value{runtimeTyp, sliceValue, low.LLVMValue(), high.LLVMValue()}
result := c.builder.CreateCall(sliceslice, args, "")
return c.NewValue(c.coerceSlice(result, sliceTyp), x.Type())
case *types.Basic:
stringslice := c.runtime.stringslice.LLVMValue()
llv := x.LLVMValue()
args := []llvm.Value{
c.coerceString(llv, stringslice.Type().ElementType().ParamTypes()[0]),
low.LLVMValue(),
high.LLVMValue(),
}
result := c.builder.CreateCall(stringslice, args, "")
return c.NewValue(c.coerceString(result, llv.Type()), x.Type())
default:
panic("unimplemented")
}
panic("unreachable")
}
func (c *compiler) coerceString(v llvm.Value, typ llvm.Type) llvm.Value {
result := llvm.Undef(typ)
ptr := c.builder.CreateExtractValue(v, 0, "")
len := c.builder.CreateExtractValue(v, 1, "")
result = c.builder.CreateInsertValue(result, ptr, 0, "")
result = c.builder.CreateInsertValue(result, len, 1, "")
return result
}
// coerceSlice takes a slice of one element type and coerces it to a
// slice of another.
func (c *compiler) coerceSlice(src llvm.Value, dsttyp llvm.Type) llvm.Value {
dst := llvm.Undef(dsttyp)
srcmem := c.builder.CreateExtractValue(src, 0, "")
srclen := c.builder.CreateExtractValue(src, 1, "")
srccap := c.builder.CreateExtractValue(src, 2, "")
dstmemtyp := dsttyp.StructElementTypes()[0]
dstmem := c.builder.CreateBitCast(srcmem, dstmemtyp, "")
dst = c.builder.CreateInsertValue(dst, dstmem, 0, "")
dst = c.builder.CreateInsertValue(dst, srclen, 1, "")
dst = c.builder.CreateInsertValue(dst, srccap, 2, "")
return dst
}
// makeClosure creates a closure from a function pointer and
// a set of bindings. The bindings are addresses of captured
// variables.
func (c *compiler) makeClosure(fn *LLVMValue, bindings []*LLVMValue) *LLVMValue {
types := make([]llvm.Type, len(bindings))
for i, binding := range bindings {
types[i] = c.types.ToLLVM(binding.Type())
}
block := c.createTypeMalloc(llvm.StructType(types, false))
for i, binding := range bindings {
addressPtr := c.builder.CreateStructGEP(block, i, "")
c.builder.CreateStore(binding.LLVMValue(), addressPtr)
}
block = c.builder.CreateBitCast(block, llvm.PointerType(llvm.Int8Type(), 0), "")
// fn is a raw function pointer; ToLLVM yields {*fn, *uint8}.
closure := llvm.Undef(c.types.ToLLVM(fn.Type()))
fnptr := c.builder.CreateBitCast(fn.LLVMValue(), closure.Type().StructElementTypes()[0], "")
closure = c.builder.CreateInsertValue(closure, fnptr, 0, "")
closure = c.builder.CreateInsertValue(closure, block, 1, "")
return c.NewValue(closure, fn.Type())
}
// makeLiteralSlice allocates a new slice, storing in it the provided elements.
func (c *compiler) makeLiteralSlice(v []llvm.Value, elttyp types.Type) llvm.Value {
n := llvm.ConstInt(c.types.inttype, uint64(len(v)), false)
eltType := c.types.ToLLVM(elttyp)
arrayType := llvm.ArrayType(eltType, len(v))
mem := c.createMalloc(llvm.SizeOf(arrayType))
mem = c.builder.CreateIntToPtr(mem, llvm.PointerType(eltType, 0), "")
for i, value := range v {
indices := []llvm.Value{llvm.ConstInt(llvm.Int32Type(), uint64(i), false)}
ep := c.builder.CreateGEP(mem, indices, "")
c.builder.CreateStore(value, ep)
}
slicetyp := types.NewSlice(elttyp)
struct_ := llvm.Undef(c.types.ToLLVM(slicetyp))
struct_ = c.builder.CreateInsertValue(struct_, mem, 0, "")
struct_ = c.builder.CreateInsertValue(struct_, n, 1, "")
struct_ = c.builder.CreateInsertValue(struct_, n, 2, "")
return struct_
}
// chanRecv implements x[, ok] = <-ch
func (c *compiler) chanRecv(ch *LLVMValue, commaOk bool) *LLVMValue {
elemtyp := ch.Type().Underlying().(*types.Chan).Elem()
stackptr := c.stacksave()
ptr := c.builder.CreateAlloca(c.types.ToLLVM(elemtyp), "")
chanrecv := c.runtime.chanrecv.LLVMValue()
chantyp := c.types.ToRuntime(ch.Type().Underlying())
chantyp = c.builder.CreateBitCast(chantyp, chanrecv.Type().ElementType().ParamTypes()[0], "")
ok := c.builder.CreateCall(chanrecv, []llvm.Value{
chantyp,
ch.LLVMValue(),
c.builder.CreatePtrToInt(ptr, c.target.IntPtrType(), ""),
boolLLVMValue(false), // nb
}, "")
elem := c.builder.CreateLoad(ptr, "")
c.stackrestore(stackptr)
if !commaOk {
return c.NewValue(elem, elemtyp)
}
typ := tupleType(elemtyp, types.Typ[types.Bool])
tuple := llvm.Undef(c.types.ToLLVM(typ))
tuple = c.builder.CreateInsertValue(tuple, elem, 0, "")
tuple = c.builder.CreateInsertValue(tuple, ok, 1, "")
return c.NewValue(tuple, typ)
}
// indirectFunction creates an indirect function from a
// given function and arguments, suitable for use with
// "defer" and "go".
func (c *compiler) indirectFunction(fn *LLVMValue, args []*LLVMValue) *LLVMValue {
nilarytyp := types.NewSignature(nil, nil, nil, nil, false)
if len(args) == 0 {
val := fn.LLVMValue()
ptr := c.builder.CreateExtractValue(val, 0, "")
ctx := c.builder.CreateExtractValue(val, 1, "")
fnval := llvm.Undef(c.types.ToLLVM(nilarytyp))
ptr = c.builder.CreateBitCast(ptr, fnval.Type().StructElementTypes()[0], "")
ctx = c.builder.CreateBitCast(ctx, fnval.Type().StructElementTypes()[1], "")
fnval = c.builder.CreateInsertValue(fnval, ptr, 0, "")
fnval = c.builder.CreateInsertValue(fnval, ctx, 1, "")
return c.NewValue(fnval, nilarytyp)
}
// Check if function pointer or context pointer is global/null.
fnval := fn.LLVMValue()
fnptr := fnval
var nctx int
var fnctx llvm.Value
var fnctxindex uint64
var globalfn bool
if fnptr.Type().TypeKind() == llvm.StructTypeKind {
fnptr = c.builder.CreateExtractValue(fnval, 0, "")
fnctx = c.builder.CreateExtractValue(fnval, 1, "")
globalfn = !fnptr.IsAFunction().IsNil()
if !globalfn {
nctx++
}
if !fnctx.IsNull() {
fnctxindex = uint64(nctx)
nctx++
}
} else {
// We've got a raw global function pointer. Convert to <ptr,ctx>.
fnval = llvm.ConstNull(c.types.ToLLVM(fn.Type()))
fnval = llvm.ConstInsertValue(fnval, fnptr, []uint32{0})
fn = c.NewValue(fnval, fn.Type())
fnctx = llvm.ConstExtractValue(fnval, []uint32{1})
globalfn = true
}
i8ptr := llvm.PointerType(llvm.Int8Type(), 0)
llvmargs := make([]llvm.Value, len(args)+nctx)
llvmargtypes := make([]llvm.Type, len(args)+nctx)
for i, arg := range args {
llvmargs[i+nctx] = arg.LLVMValue()
llvmargtypes[i+nctx] = llvmargs[i+nctx].Type()
}
if !globalfn {
llvmargtypes[0] = fnptr.Type()
llvmargs[0] = fnptr
}
if !fnctx.IsNull() {
llvmargtypes[fnctxindex] = fnctx.Type()
llvmargs[fnctxindex] = fnctx
}
// TODO(axw) investigate an option for go statements
// to allocate argument structure on the stack in the
// initiator, and block until the spawned goroutine
// has loaded the arguments from it.
structtyp := llvm.StructType(llvmargtypes, false)
argstruct := c.createTypeMalloc(structtyp)
for i, llvmarg := range llvmargs {
argptr := c.builder.CreateGEP(argstruct, []llvm.Value{
llvm.ConstInt(llvm.Int32Type(), 0, false),
llvm.ConstInt(llvm.Int32Type(), uint64(i), false)}, "")
c.builder.CreateStore(llvmarg, argptr)
}
// Create a function that will take a pointer to a structure of the type
// defined above, or no parameters if there are none to pass.
fntype := llvm.FunctionType(llvm.VoidType(), []llvm.Type{argstruct.Type()}, false)
indirectfn := llvm.AddFunction(c.module.Module, "", fntype)
i8argstruct := c.builder.CreateBitCast(argstruct, i8ptr, "")
currblock := c.builder.GetInsertBlock()
c.builder.SetInsertPointAtEnd(llvm.AddBasicBlock(indirectfn, "entry"))
argstruct = indirectfn.Param(0)
newargs := make([]*LLVMValue, len(args))
for i := range llvmargs[nctx:] {
argptr := c.builder.CreateGEP(argstruct, []llvm.Value{
llvm.ConstInt(llvm.Int32Type(), 0, false),
llvm.ConstInt(llvm.Int32Type(), uint64(i+nctx), false)}, "")
newargs[i] = c.NewValue(c.builder.CreateLoad(argptr, ""), args[i].Type())
}
// Unless we've got a global function, extract the
// function pointer from the context.
if !globalfn {
fnval = llvm.Undef(fnval.Type())
fnptrptr := c.builder.CreateGEP(argstruct, []llvm.Value{
llvm.ConstInt(llvm.Int32Type(), 0, false),
llvm.ConstInt(llvm.Int32Type(), 0, false)}, "")
fnptr = c.builder.CreateLoad(fnptrptr, "")
fnval = c.builder.CreateInsertValue(fnval, fnptr, 0, "")
}
if !fnctx.IsNull() {
fnctxptr := c.builder.CreateGEP(argstruct, []llvm.Value{
llvm.ConstInt(llvm.Int32Type(), 0, false),
llvm.ConstInt(llvm.Int32Type(), fnctxindex, false)}, "")
fnctx = c.builder.CreateLoad(fnctxptr, "")
fnval = c.builder.CreateInsertValue(fnval, fnctx, 1, "")
fn = c.NewValue(fnval, fn.Type())
}
c.createCall(fn, newargs)
// Indirect function calls' return values are always ignored.
c.builder.CreateRetVoid()
c.builder.SetInsertPointAtEnd(currblock)
fnval = llvm.Undef(c.types.ToLLVM(nilarytyp))
indirectfn = c.builder.CreateBitCast(indirectfn, fnval.Type().StructElementTypes()[0], "")
fnval = c.builder.CreateInsertValue(fnval, indirectfn, 0, "")
fnval = c.builder.CreateInsertValue(fnval, i8argstruct, 1, "")
fn = c.NewValue(fnval, nilarytyp)
return fn
}
func (c *compiler) NewConstValue(v exact.Value, typ types.Type) *LLVMValue {
switch {
case v == nil:
llvmtyp := c.types.ToLLVM(typ)
return c.NewValue(llvm.ConstNull(llvmtyp), typ)
case isString(typ):
if isUntyped(typ) {
typ = types.Typ[types.String]
}
llvmtyp := c.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(c.module.Module, init.Type(), "")
ptr.SetInitializer(init)
ptr = llvm.ConstBitCast(ptr, i8ptr)
} else {
ptr = llvm.ConstNull(i8ptr)
}
len_ := llvm.ConstInt(c.types.inttype, uint64(strlen), false)
llvmvalue := llvm.Undef(llvmtyp)
llvmvalue = llvm.ConstInsertValue(llvmvalue, ptr, []uint32{0})
llvmvalue = llvm.ConstInsertValue(llvmvalue, len_, []uint32{1})
return c.NewValue(llvmvalue, typ)
case isInteger(typ):
if isUntyped(typ) {
typ = types.Typ[types.Int]
}
llvmtyp := c.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 c.NewValue(llvmvalue, typ)
case isBoolean(typ):
if isUntyped(typ) {
typ = types.Typ[types.Bool]
}
var llvmvalue llvm.Value
if exact.BoolVal(v) {
llvmvalue = llvm.ConstAllOnes(llvm.Int1Type())
} else {
llvmvalue = llvm.ConstNull(llvm.Int1Type())
}
return c.NewValue(llvmvalue, typ)
case isFloat(typ):
if isUntyped(typ) {
typ = types.Typ[types.Float64]
}
llvmtyp := c.types.ToLLVM(typ)
floatval, _ := exact.Float64Val(v)
llvmvalue := llvm.ConstFloat(llvmtyp, floatval)
return c.NewValue(llvmvalue, typ)
case typ == types.Typ[types.UnsafePointer]:
llvmtyp := c.types.ToLLVM(typ)
v, _ := exact.Uint64Val(v)
llvmvalue := llvm.ConstInt(llvmtyp, v, false)
return c.NewValue(llvmvalue, typ)
case isComplex(typ):
if isUntyped(typ) {
typ = types.Typ[types.Complex128]
}
llvmtyp := c.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 c.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 := c.NewConstValue(v, types.Typ[types.String])
return strval.Convert(typ).(*LLVMValue)
}
}
panic(fmt.Sprintf("unhandled: t=%s(%T), v=%v(%T)", typ, typ, v, v))
}
func (v *LLVMValue) Convert(dsttyp types.Type) Value {
b := v.compiler.builder
// If it's a stack allocated value, we'll want to compare the
// value type, not the pointer type.
srctyp := v.typ
// Get the underlying type, if any.
origdsttyp := dsttyp
dsttyp = dsttyp.Underlying()
srctyp = srctyp.Underlying()
// Identical (underlying) types? Just swap in the destination type.
if types.Identical(srctyp, dsttyp) {
return v.compiler.NewValue(v.LLVMValue(), origdsttyp)
}
// Both pointer types with identical underlying types? Same as above.
if srctyp, ok := srctyp.(*types.Pointer); ok {
if dsttyp, ok := dsttyp.(*types.Pointer); ok {
srctyp := srctyp.Elem().Underlying()
dsttyp := dsttyp.Elem().Underlying()
if types.Identical(srctyp, dsttyp) {
return v.compiler.NewValue(v.LLVMValue(), origdsttyp)
}
}
}
byteslice := types.NewSlice(types.Typ[types.Byte])
runeslice := types.NewSlice(types.Typ[types.Rune])
// string ->
if isString(srctyp) {
// (untyped) string -> string
// XXX should untyped strings be able to escape go/types?
if isString(dsttyp) {
return v.compiler.NewValue(v.LLVMValue(), origdsttyp)
}
// string -> []byte
if types.Identical(dsttyp, byteslice) {
c := v.compiler
value := v.LLVMValue()
strdata := c.builder.CreateExtractValue(value, 0, "")
strlen := c.builder.CreateExtractValue(value, 1, "")
// Data must be copied, to prevent changes in
// the byte slice from mutating the string.
newdata := c.createMalloc(strlen)
memcpy := c.runtime.memcpy.LLVMValue()
c.builder.CreateCall(memcpy, []llvm.Value{
newdata,
c.builder.CreatePtrToInt(strdata, c.target.IntPtrType(), ""),
strlen,
}, "")
strdata = c.builder.CreateIntToPtr(newdata, strdata.Type(), "")
struct_ := llvm.Undef(c.types.ToLLVM(byteslice))
struct_ = c.builder.CreateInsertValue(struct_, strdata, 0, "")
struct_ = c.builder.CreateInsertValue(struct_, strlen, 1, "")
struct_ = c.builder.CreateInsertValue(struct_, strlen, 2, "")
return c.NewValue(struct_, byteslice)
}
// string -> []rune
if types.Identical(dsttyp, runeslice) {
return v.stringToRuneSlice()
}
}
// []byte -> string
if types.Identical(srctyp, byteslice) && isString(dsttyp) {
c := v.compiler
value := v.LLVMValue()
data := c.builder.CreateExtractValue(value, 0, "")
len := c.builder.CreateExtractValue(value, 1, "")
// Data must be copied, to prevent changes in
// the byte slice from mutating the string.
newdata := c.createMalloc(len)
memcpy := c.runtime.memcpy.LLVMValue()
c.builder.CreateCall(memcpy, []llvm.Value{
newdata,
c.builder.CreatePtrToInt(data, c.target.IntPtrType(), ""),
len,
}, "")
data = c.builder.CreateIntToPtr(newdata, data.Type(), "")
struct_ := llvm.Undef(c.types.ToLLVM(types.Typ[types.String]))
struct_ = c.builder.CreateInsertValue(struct_, data, 0, "")
struct_ = c.builder.CreateInsertValue(struct_, len, 1, "")
return c.NewValue(struct_, types.Typ[types.String])
}
// []rune -> string
if types.Identical(srctyp, runeslice) && isString(dsttyp) {
return v.runeSliceToString()
}
// rune -> string
if isString(dsttyp) && isInteger(srctyp) {
return v.runeToString()
}
// TODO other special conversions?
llvm_type := v.compiler.types.ToLLVM(dsttyp)
// Unsafe pointer conversions.
if dsttyp == types.Typ[types.UnsafePointer] { // X -> unsafe.Pointer
if _, isptr := srctyp.(*types.Pointer); isptr {
value := b.CreatePtrToInt(v.LLVMValue(), llvm_type, "")
return v.compiler.NewValue(value, origdsttyp)
} else if srctyp == types.Typ[types.Uintptr] {
return v.compiler.NewValue(v.LLVMValue(), origdsttyp)
}
} else if srctyp == types.Typ[types.UnsafePointer] { // unsafe.Pointer -> X
if _, isptr := dsttyp.(*types.Pointer); isptr {
value := b.CreateIntToPtr(v.LLVMValue(), llvm_type, "")
return v.compiler.NewValue(value, origdsttyp)
} else if dsttyp == types.Typ[types.Uintptr] {
return v.compiler.NewValue(v.LLVMValue(), origdsttyp)
}
}
lv := v.LLVMValue()
srcType := lv.Type()
switch srcType.TypeKind() {
case llvm.IntegerTypeKind:
switch llvm_type.TypeKind() {
case llvm.IntegerTypeKind:
srcBits := srcType.IntTypeWidth()
dstBits := llvm_type.IntTypeWidth()
delta := srcBits - dstBits
switch {
case delta < 0:
if !isUnsigned(srctyp) {
lv = b.CreateSExt(lv, llvm_type, "")
} else {
lv = b.CreateZExt(lv, llvm_type, "")
}
case delta > 0:
lv = b.CreateTrunc(lv, llvm_type, "")
}
return v.compiler.NewValue(lv, origdsttyp)
case llvm.FloatTypeKind, llvm.DoubleTypeKind:
if !isUnsigned(v.Type()) {
lv = b.CreateSIToFP(lv, llvm_type, "")
} else {
lv = b.CreateUIToFP(lv, llvm_type, "")
}
return v.compiler.NewValue(lv, origdsttyp)
}
case llvm.DoubleTypeKind:
switch llvm_type.TypeKind() {
case llvm.FloatTypeKind:
lv = b.CreateFPTrunc(lv, llvm_type, "")
return v.compiler.NewValue(lv, origdsttyp)
case llvm.IntegerTypeKind:
if !isUnsigned(dsttyp) {
lv = b.CreateFPToSI(lv, llvm_type, "")
} else {
lv = b.CreateFPToUI(lv, llvm_type, "")
}
return v.compiler.NewValue(lv, origdsttyp)
}
case llvm.FloatTypeKind:
switch llvm_type.TypeKind() {
case llvm.DoubleTypeKind:
lv = b.CreateFPExt(lv, llvm_type, "")
return v.compiler.NewValue(lv, origdsttyp)
case llvm.IntegerTypeKind:
if !isUnsigned(dsttyp) {
lv = b.CreateFPToSI(lv, llvm_type, "")
} else {
lv = b.CreateFPToUI(lv, llvm_type, "")
}
return v.compiler.NewValue(lv, origdsttyp)
}
}
// Complex -> complex. Complexes are only convertible to other
// complexes, contant conversions aside. So we can just check the
// source type here; given that the types are not identical
// (checked above), we can assume the destination type is the alternate
// complex type.
if isComplex(srctyp) {
var fpcast func(llvm.Builder, llvm.Value, llvm.Type, string) llvm.Value
var fptype llvm.Type
if srctyp == types.Typ[types.Complex64] {
fpcast = (llvm.Builder).CreateFPExt
fptype = llvm.DoubleType()
} else {
fpcast = (llvm.Builder).CreateFPTrunc
fptype = llvm.FloatType()
}
if fpcast != nil {
realv := b.CreateExtractValue(lv, 0, "")
imagv := b.CreateExtractValue(lv, 1, "")
realv = fpcast(b, realv, fptype, "")
imagv = fpcast(b, imagv, fptype, "")
lv = llvm.Undef(v.compiler.types.ToLLVM(dsttyp))
lv = b.CreateInsertValue(lv, realv, 0, "")
lv = b.CreateInsertValue(lv, imagv, 1, "")
return v.compiler.NewValue(lv, origdsttyp)
}
}
panic(fmt.Sprintf("unimplemented conversion: %s (%s) -> %s", v.typ, lv.Type(), origdsttyp))
}
// prepareCall returns the evaluated function and arguments.
//
// For builtins that may not be used in go/defer, prepareCall
// will emits inline code. In this case, prepareCall returns
// nil for fn and args, and returns a non-nil value for result.
func (fr *frame) prepareCall(instr ssa.CallInstruction) (fn *LLVMValue, args []*LLVMValue, result *LLVMValue) {
call := instr.Common()
args = make([]*LLVMValue, len(call.Args))
for i, arg := range call.Args {
args[i] = fr.value(arg)
}
if call.IsInvoke() {
fn := fr.interfaceMethod(fr.value(call.Value), call.Method)
return fn, args, nil
}
switch v := call.Value.(type) {
case *ssa.Builtin:
// handled below
case *ssa.Function:
// Function handled specially; value() will convert
// a function to one with a context argument.
fn = fr.resolveFunction(v)
pair := llvm.ConstNull(fr.llvmtypes.ToLLVM(fn.Type()))
pair = llvm.ConstInsertValue(pair, fn.LLVMValue(), []uint32{0})
fn = fr.NewValue(pair, fn.Type())
return fn, args, nil
default:
fn = fr.value(call.Value)
return fn, args, nil
}
// Builtins may only be used in calls (i.e. can't be assigned),
// and only print[ln], panic and recover may be used in go/defer.
builtin := call.Value.(*ssa.Builtin)
switch builtin.Name() {
case "print", "println":
// print/println generates a call-site specific anonymous
// function to print the values. It's not inline because
// print/println may be deferred.
params := make([]*types.Var, len(call.Args))
for i, arg := range call.Args {
// make sure to use args[i].Type(), not call.Args[i].Type(),
// as the evaluated expression converts untyped.
params[i] = types.NewParam(arg.Pos(), nil, arg.Name(), args[i].Type())
}
sig := types.NewSignature(nil, nil, types.NewTuple(params...), nil, false)
llfntyp := fr.llvmtypes.ToLLVM(sig)
llfnptr := llvm.AddFunction(fr.module.Module, "", llfntyp.StructElementTypes()[0].ElementType())
currBlock := fr.builder.GetInsertBlock()
entry := llvm.AddBasicBlock(llfnptr, "entry")
fr.builder.SetInsertPointAtEnd(entry)
internalArgs := make([]Value, len(args))
for i, arg := range args {
internalArgs[i] = fr.NewValue(llfnptr.Param(i), arg.Type())
}
fr.printValues(builtin.Name() == "println", internalArgs...)
fr.builder.CreateRetVoid()
fr.builder.SetInsertPointAtEnd(currBlock)
return fr.NewValue(llfnptr, sig), args, nil
case "panic":
panic("TODO: panic")
case "recover":
// TODO(axw) determine number of frames to skip in pc check
indirect := fr.NewValue(llvm.ConstNull(llvm.Int32Type()), types.Typ[types.Int32])
return fr.runtime.recover_, []*LLVMValue{indirect}, nil
case "append":
return nil, nil, fr.callAppend(args[0], args[1])
case "close":
return fr.runtime.chanclose, args, nil
case "cap":
return nil, nil, fr.callCap(args[0])
case "len":
return nil, nil, fr.callLen(args[0])
case "copy":
return nil, nil, fr.callCopy(args[0], args[1])
case "delete":
fr.callDelete(args[0], args[1])
return nil, nil, nil
case "real":
return nil, nil, args[0].extractComplexComponent(0)
case "imag":
return nil, nil, args[0].extractComplexComponent(1)
case "complex":
r := args[0].LLVMValue()
i := args[1].LLVMValue()
typ := instr.Value().Type()
cmplx := llvm.Undef(fr.llvmtypes.ToLLVM(typ))
cmplx = fr.builder.CreateInsertValue(cmplx, r, 0, "")
cmplx = fr.builder.CreateInsertValue(cmplx, i, 1, "")
return nil, nil, fr.NewValue(cmplx, typ)
default:
panic("unimplemented: " + builtin.Name())
}
}
func (fr *frame) instruction(instr ssa.Instruction) {
fr.logf("[%T] %v @ %s\n", instr, instr, fr.pkg.Prog.Fset.Position(instr.Pos()))
if fr.GenerateDebug {
fr.debug.setLocation(fr.builder, instr.Pos())
}
// Check if we'll need to backpatch; see comment
// in fr.value().
if v, ok := instr.(ssa.Value); ok {
if b := fr.backpatcher(v); b != nil {
defer b()
}
}
switch instr := instr.(type) {
case *ssa.Alloc:
typ := fr.llvmtypes.ToLLVM(deref(instr.Type()))
var value llvm.Value
if instr.Heap {
value = fr.createTypeMalloc(typ)
value.SetName(instr.Comment)
fr.env[instr] = fr.NewValue(value, instr.Type())
} else {
value = fr.env[instr].LLVMValue()
}
fr.memsetZero(value, llvm.SizeOf(typ))
case *ssa.BinOp:
lhs, rhs := fr.value(instr.X), fr.value(instr.Y)
fr.env[instr] = lhs.BinaryOp(instr.Op, rhs).(*LLVMValue)
case *ssa.Call:
fn, args, result := fr.prepareCall(instr)
// Some builtins may only be used immediately, and not
// deferred; in this case, "fn" will be nil, and result
// may be non-nil (it will be nil for builtins without
// results.)
if fn == nil {
if result != nil {
fr.env[instr] = result
}
} else {
result = fr.createCall(fn, args)
fr.env[instr] = result
}
case *ssa.ChangeInterface:
x := fr.value(instr.X)
// The source type must be a non-empty interface,
// as ChangeInterface cannot fail (E2I may fail).
if instr.Type().Underlying().(*types.Interface).NumMethods() > 0 {
// TODO(axw) optimisation for I2I case where we
// know statically the methods to carry over.
x = x.convertI2E()
x, _ = x.convertE2I(instr.Type())
} else {
x = x.convertI2E()
x = fr.NewValue(x.LLVMValue(), instr.Type())
}
fr.env[instr] = x
case *ssa.ChangeType:
value := fr.value(instr.X).LLVMValue()
if _, ok := instr.Type().Underlying().(*types.Pointer); ok {
value = fr.builder.CreateBitCast(value, fr.llvmtypes.ToLLVM(instr.Type()), "")
}
v := fr.NewValue(value, instr.Type())
if _, ok := instr.X.(*ssa.Phi); ok {
v = phiValue(fr.compiler, v)
}
fr.env[instr] = v
case *ssa.Convert:
v := fr.value(instr.X)
if _, ok := instr.X.(*ssa.Phi); ok {
v = phiValue(fr.compiler, v)
}
fr.env[instr] = v.Convert(instr.Type()).(*LLVMValue)
//case *ssa.DebugRef:
case *ssa.Defer:
fn, args, result := fr.prepareCall(instr)
if result != nil {
panic("illegal use of builtin in defer statement")
}
fn = fr.indirectFunction(fn, args)
fr.createCall(fr.runtime.pushdefer, []*LLVMValue{fn})
case *ssa.Extract:
tuple := fr.value(instr.Tuple).LLVMValue()
elem := fr.builder.CreateExtractValue(tuple, instr.Index, instr.Name())
elemtyp := instr.Type()
fr.env[instr] = fr.NewValue(elem, elemtyp)
case *ssa.Field:
value := fr.value(instr.X).LLVMValue()
field := fr.builder.CreateExtractValue(value, instr.Field, instr.Name())
fieldtyp := instr.Type()
fr.env[instr] = fr.NewValue(field, fieldtyp)
case *ssa.FieldAddr:
// TODO: implement nil check and panic.
// TODO: combine a chain of {Field,Index}Addrs into a single GEP.
ptr := fr.value(instr.X).LLVMValue()
fieldptr := fr.builder.CreateStructGEP(ptr, instr.Field, instr.Name())
fieldptrtyp := instr.Type()
fr.env[instr] = fr.NewValue(fieldptr, fieldptrtyp)
case *ssa.Go:
fn, args, result := fr.prepareCall(instr)
if result != nil {
panic("illegal use of builtin in go statement")
}
fn = fr.indirectFunction(fn, args)
fr.createCall(fr.runtime.Go, []*LLVMValue{fn})
case *ssa.If:
cond := fr.value(instr.Cond).LLVMValue()
block := instr.Block()
trueBlock := fr.block(block.Succs[0])
falseBlock := fr.block(block.Succs[1])
fr.builder.CreateCondBr(cond, trueBlock, falseBlock)
case *ssa.Index:
// FIXME Surely we should be dealing with an
// *array, so we can do a GEP?
array := fr.value(instr.X).LLVMValue()
arrayptr := fr.builder.CreateAlloca(array.Type(), "")
fr.builder.CreateStore(array, arrayptr)
index := fr.value(instr.Index).LLVMValue()
zero := llvm.ConstNull(index.Type())
addr := fr.builder.CreateGEP(arrayptr, []llvm.Value{zero, index}, "")
fr.env[instr] = fr.NewValue(fr.builder.CreateLoad(addr, ""), instr.Type())
case *ssa.IndexAddr:
// TODO: implement nil-check and panic.
// TODO: combine a chain of {Field,Index}Addrs into a single GEP.
x := fr.value(instr.X).LLVMValue()
index := fr.value(instr.Index).LLVMValue()
var addr llvm.Value
var elemtyp types.Type
zero := llvm.ConstNull(index.Type())
switch typ := instr.X.Type().Underlying().(type) {
case *types.Slice:
elemtyp = typ.Elem()
x = fr.builder.CreateExtractValue(x, 0, "")
addr = fr.builder.CreateGEP(x, []llvm.Value{index}, "")
case *types.Pointer: // *array
elemtyp = typ.Elem().Underlying().(*types.Array).Elem()
addr = fr.builder.CreateGEP(x, []llvm.Value{zero, index}, "")
}
fr.env[instr] = fr.NewValue(addr, types.NewPointer(elemtyp))
case *ssa.Jump:
succ := instr.Block().Succs[0]
fr.builder.CreateBr(fr.block(succ))
case *ssa.Lookup:
x := fr.value(instr.X)
index := fr.value(instr.Index)
if isString(x.Type().Underlying()) {
fr.env[instr] = fr.stringIndex(x, index)
} else {
fr.env[instr] = fr.mapLookup(x, index, instr.CommaOk)
}
case *ssa.MakeChan:
fr.env[instr] = fr.makeChan(instr.Type(), fr.value(instr.Size))
case *ssa.MakeClosure:
fn := fr.resolveFunction(instr.Fn.(*ssa.Function))
bindings := make([]*LLVMValue, len(instr.Bindings))
for i, binding := range instr.Bindings {
bindings[i] = fr.value(binding)
}
fr.env[instr] = fr.makeClosure(fn, bindings)
case *ssa.MakeInterface:
receiver := fr.value(instr.X)
fr.env[instr] = fr.makeInterface(receiver, instr.Type())
case *ssa.MakeMap:
fr.env[instr] = fr.makeMap(instr.Type(), fr.value(instr.Reserve))
case *ssa.MakeSlice:
length := fr.value(instr.Len)
capacity := fr.value(instr.Cap)
fr.env[instr] = fr.makeSlice(instr.Type(), length, capacity)
case *ssa.MapUpdate:
m := fr.value(instr.Map)
k := fr.value(instr.Key)
v := fr.value(instr.Value)
fr.mapUpdate(m, k, v)
case *ssa.Next:
iter := fr.value(instr.Iter)
if !instr.IsString {
fr.env[instr] = fr.mapIterNext(iter)
return
}
// String range
//
// We make some assumptions for now around the
// current state of affairs in go.tools/ssa.
//
// - Range's block is a predecessor of Next's.
// (this is currently true, but may change in the future;
// adonovan says he will expose the dominator tree
// computation in the future, which we can use here).
// - Next is the first non-Phi instruction in its block.
// (this is not strictly necessary; we can move the Phi
// to the top of the block, and defer the tuple creation
// to Extract).
assert(instr.Iter.(*ssa.Range).Block() == instr.Block().Preds[0])
for _, blockInstr := range instr.Block().Instrs {
if instr == blockInstr {
break
}
_, isphi := blockInstr.(*ssa.Phi)
assert(isphi)
}
preds := instr.Block().Preds
llpreds := make([]llvm.BasicBlock, len(preds))
for i, b := range preds {
llpreds[i] = fr.block(b)
}
fr.env[instr] = fr.stringIterNext(iter, llpreds)
case *ssa.Panic:
arg := fr.value(instr.X).LLVMValue()
fr.builder.CreateCall(fr.runtime.panic_.LLVMValue(), []llvm.Value{arg}, "")
fr.builder.CreateUnreachable()
case *ssa.Phi:
typ := instr.Type()
phi := fr.builder.CreatePHI(fr.llvmtypes.ToLLVM(typ), instr.Comment)
fr.env[instr] = fr.NewValue(phi, typ)
values := make([]llvm.Value, len(instr.Edges))
blocks := make([]llvm.BasicBlock, len(instr.Edges))
block := instr.Block()
for i, edge := range instr.Edges {
values[i] = fr.value(edge).LLVMValue()
blocks[i] = fr.block(block.Preds[i])
}
phi.AddIncoming(values, blocks)
case *ssa.Range:
x := fr.value(instr.X)
switch x.Type().Underlying().(type) {
case *types.Map:
fr.env[instr] = fr.mapIterInit(x)
case *types.Basic: // string
fr.env[instr] = x
default:
panic(fmt.Sprintf("unhandled range for type %T", x.Type()))
}
case *ssa.Return:
switch n := len(instr.Results); n {
case 0:
// https://code.google.com/p/go/issues/detail?id=7022
if r := instr.Parent().Signature.Results(); r != nil && r.Len() > 0 {
fr.builder.CreateUnreachable()
} else {
fr.builder.CreateRetVoid()
}
case 1:
fr.builder.CreateRet(fr.value(instr.Results[0]).LLVMValue())
default:
values := make([]llvm.Value, n)
for i, result := range instr.Results {
values[i] = fr.value(result).LLVMValue()
}
fr.builder.CreateAggregateRet(values)
}
case *ssa.RunDefers:
fr.builder.CreateCall(fr.runtime.rundefers.LLVMValue(), nil, "")
case *ssa.Select:
states := make([]selectState, len(instr.States))
for i, state := range instr.States {
states[i] = selectState{
Dir: state.Dir,
Chan: fr.value(state.Chan),
Send: fr.value(state.Send),
}
}
fr.env[instr] = fr.chanSelect(states, instr.Blocking)
case *ssa.Send:
fr.chanSend(fr.value(instr.Chan), fr.value(instr.X))
case *ssa.Slice:
x := fr.value(instr.X)
low := fr.value(instr.Low)
high := fr.value(instr.High)
fr.env[instr] = fr.slice(x, low, high)
case *ssa.Store:
addr := fr.value(instr.Addr).LLVMValue()
value := fr.value(instr.Val).LLVMValue()
// The bitcast is necessary to handle recursive pointer stores.
addr = fr.builder.CreateBitCast(addr, llvm.PointerType(value.Type(), 0), "")
fr.builder.CreateStore(value, addr)
case *ssa.TypeAssert:
x := fr.value(instr.X)
if iface, ok := x.Type().Underlying().(*types.Interface); ok && iface.NumMethods() > 0 {
x = x.convertI2E()
}
if !instr.CommaOk {
if _, ok := instr.AssertedType.Underlying().(*types.Interface); ok {
fr.env[instr] = x.mustConvertE2I(instr.AssertedType)
} else {
fr.env[instr] = x.mustConvertE2V(instr.AssertedType)
}
} else {
var result, success *LLVMValue
if _, ok := instr.AssertedType.Underlying().(*types.Interface); ok {
result, success = x.convertE2I(instr.AssertedType)
} else {
result, success = x.convertE2V(instr.AssertedType)
}
resultval := result.LLVMValue()
okval := success.LLVMValue()
pairtyp := llvm.StructType([]llvm.Type{resultval.Type(), okval.Type()}, false)
pair := llvm.Undef(pairtyp)
pair = fr.builder.CreateInsertValue(pair, resultval, 0, "")
pair = fr.builder.CreateInsertValue(pair, okval, 1, "")
fr.env[instr] = fr.NewValue(pair, instr.Type())
}
case *ssa.UnOp:
operand := fr.value(instr.X)
switch instr.Op {
case token.ARROW:
fr.env[instr] = fr.chanRecv(operand, instr.CommaOk)
case token.MUL:
// The bitcast is necessary to handle recursive pointer loads.
llptr := fr.builder.CreateBitCast(operand.LLVMValue(), llvm.PointerType(fr.llvmtypes.ToLLVM(instr.Type()), 0), "")
fr.env[instr] = fr.NewValue(fr.builder.CreateLoad(llptr, ""), instr.Type())
default:
fr.env[instr] = operand.UnaryOp(instr.Op).(*LLVMValue)
}
default:
panic(fmt.Sprintf("unhandled: %v", instr))
}
}
