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())
}
switch instr := instr.(type) {
case *ssa.Alloc:
typ := deref(instr.Type())
llvmtyp := fr.llvmtypes.ToLLVM(typ)
var value llvm.Value
if !instr.Heap {
value = fr.env[instr].value
fr.memsetZero(value, llvm.SizeOf(llvmtyp))
} else if fr.isInit && fr.shouldStaticallyAllocate(instr) {
// If this is the init function and we think it may be beneficial,
// allocate memory statically in the object file rather than on the
// heap. This allows us to optimize constant stores into such
// variables as static initializations.
global := llvm.AddGlobal(fr.module.Module, llvmtyp, "")
global.SetLinkage(llvm.InternalLinkage)
fr.addGlobal(global, typ)
ptr := llvm.ConstBitCast(global, llvm.PointerType(llvm.Int8Type(), 0))
fr.env[instr] = newValue(ptr, instr.Type())
} else {
value = fr.createTypeMalloc(typ)
value.SetName(instr.Comment)
value = fr.builder.CreateBitCast(value, llvm.PointerType(llvm.Int8Type(), 0), "")
fr.env[instr] = newValue(value, instr.Type())
}
case *ssa.BinOp:
lhs, rhs := fr.value(instr.X), fr.value(instr.Y)
fr.env[instr] = fr.binaryOp(lhs, instr.Op, rhs)
case *ssa.Call:
tuple := fr.callInstruction(instr)
if len(tuple) == 1 {
fr.env[instr] = tuple[0]
} else {
fr.tuples[instr] = tuple
}
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 {
x = fr.changeInterface(x, instr.Type(), false)
} else {
x = fr.convertI2E(x)
}
fr.env[instr] = x
case *ssa.ChangeType:
value := fr.llvmvalue(instr.X)
if _, ok := instr.Type().Underlying().(*types.Pointer); ok {
value = fr.builder.CreateBitCast(value, fr.llvmtypes.ToLLVM(instr.Type()), "")
}
fr.env[instr] = newValue(value, instr.Type())
case *ssa.Convert:
v := fr.value(instr.X)
fr.env[instr] = fr.convert(v, instr.Type())
case *ssa.Defer:
fn, arg := fr.createThunk(instr)
fr.runtime.Defer.call(fr, fr.frameptr, fn, arg)
case *ssa.Extract:
var elem llvm.Value
if t, ok := fr.tuples[instr.Tuple]; ok {
elem = t[instr.Index].value
} else {
tuple := fr.llvmvalue(instr.Tuple)
elem = fr.builder.CreateExtractValue(tuple, instr.Index, instr.Name())
}
elemtyp := instr.Type()
fr.env[instr] = newValue(elem, elemtyp)
case *ssa.Field:
fieldtyp := instr.Type()
if p, ok := fr.ptr[instr.X]; ok {
field := fr.builder.CreateStructGEP(p, instr.Field, instr.Name())
if fr.canAvoidElementLoad(*instr.Referrers()) {
fr.ptr[instr] = field
} else {
fr.env[instr] = newValue(fr.builder.CreateLoad(field, ""), fieldtyp)
}
} else {
value := fr.llvmvalue(instr.X)
field := fr.builder.CreateExtractValue(value, instr.Field, instr.Name())
fr.env[instr] = newValue(field, fieldtyp)
}
case *ssa.FieldAddr:
ptr := fr.llvmvalue(instr.X)
fr.nilCheck(instr.X, ptr)
xtyp := instr.X.Type().Underlying().(*types.Pointer).Elem()
ptrtyp := llvm.PointerType(fr.llvmtypes.ToLLVM(xtyp), 0)
ptr = fr.builder.CreateBitCast(ptr, ptrtyp, "")
fieldptr := fr.builder.CreateStructGEP(ptr, instr.Field, instr.Name())
fieldptr = fr.builder.CreateBitCast(fieldptr, llvm.PointerType(llvm.Int8Type(), 0), "")
fieldptrtyp := instr.Type()
fr.env[instr] = newValue(fieldptr, fieldptrtyp)
case *ssa.Go:
fn, arg := fr.createThunk(instr)
fr.runtime.Go.call(fr, fn, arg)
case *ssa.If:
cond := fr.llvmvalue(instr.Cond)
block := instr.Block()
trueBlock := fr.block(block.Succs[0])
falseBlock := fr.block(block.Succs[1])
cond = fr.builder.CreateTrunc(cond, llvm.Int1Type(), "")
fr.builder.CreateCondBr(cond, trueBlock, falseBlock)
case *ssa.Index:
var arrayptr llvm.Value
if ptr, ok := fr.ptr[instr.X]; ok {
arrayptr = ptr
} else {
array := fr.llvmvalue(instr.X)
arrayptr = fr.allocaBuilder.CreateAlloca(array.Type(), "")
fr.builder.CreateStore(array, arrayptr)
}
index := fr.llvmvalue(instr.Index)
arraytyp := instr.X.Type().Underlying().(*types.Array)
arraylen := llvm.ConstInt(fr.llvmtypes.inttype, uint64(arraytyp.Len()), false)
// The index may not have been promoted to int (for example, if it
// came from a composite literal).
index = fr.createZExtOrTrunc(index, fr.types.inttype, "")
// Bounds checking: 0 <= index < len
zero := llvm.ConstNull(fr.types.inttype)
i0 := fr.builder.CreateICmp(llvm.IntSLT, index, zero, "")
li := fr.builder.CreateICmp(llvm.IntSLE, arraylen, index, "")
cond := fr.builder.CreateOr(i0, li, "")
fr.condBrRuntimeError(cond, gccgoRuntimeErrorARRAY_INDEX_OUT_OF_BOUNDS)
addr := fr.builder.CreateGEP(arrayptr, []llvm.Value{zero, index}, "")
if fr.canAvoidElementLoad(*instr.Referrers()) {
fr.ptr[instr] = addr
} else {
fr.env[instr] = newValue(fr.builder.CreateLoad(addr, ""), instr.Type())
}
case *ssa.IndexAddr:
x := fr.llvmvalue(instr.X)
index := fr.llvmvalue(instr.Index)
var arrayptr, arraylen llvm.Value
var elemtyp types.Type
var errcode uint64
switch typ := instr.X.Type().Underlying().(type) {
case *types.Slice:
elemtyp = typ.Elem()
arrayptr = fr.builder.CreateExtractValue(x, 0, "")
arraylen = fr.builder.CreateExtractValue(x, 1, "")
errcode = gccgoRuntimeErrorSLICE_INDEX_OUT_OF_BOUNDS
case *types.Pointer: // *array
arraytyp := typ.Elem().Underlying().(*types.Array)
elemtyp = arraytyp.Elem()
fr.nilCheck(instr.X, x)
arrayptr = x
arraylen = llvm.ConstInt(fr.llvmtypes.inttype, uint64(arraytyp.Len()), false)
errcode = gccgoRuntimeErrorARRAY_INDEX_OUT_OF_BOUNDS
}
// The index may not have been promoted to int (for example, if it
// came from a composite literal).
index = fr.createZExtOrTrunc(index, fr.types.inttype, "")
// Bounds checking: 0 <= index < len
zero := llvm.ConstNull(fr.types.inttype)
i0 := fr.builder.CreateICmp(llvm.IntSLT, index, zero, "")
li := fr.builder.CreateICmp(llvm.IntSLE, arraylen, index, "")
cond := fr.builder.CreateOr(i0, li, "")
fr.condBrRuntimeError(cond, errcode)
ptrtyp := llvm.PointerType(fr.llvmtypes.ToLLVM(elemtyp), 0)
arrayptr = fr.builder.CreateBitCast(arrayptr, ptrtyp, "")
addr := fr.builder.CreateGEP(arrayptr, []llvm.Value{index}, "")
addr = fr.builder.CreateBitCast(addr, llvm.PointerType(llvm.Int8Type(), 0), "")
fr.env[instr] = 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 {
v, ok := fr.mapLookup(x, index)
if instr.CommaOk {
fr.tuples[instr] = []*govalue{v, ok}
} else {
fr.env[instr] = v
}
}
case *ssa.MakeChan:
fr.env[instr] = fr.makeChan(instr.Type(), fr.value(instr.Size))
case *ssa.MakeClosure:
llfn := fr.resolveFunctionGlobal(instr.Fn.(*ssa.Function))
llfn = llvm.ConstBitCast(llfn, llvm.PointerType(llvm.Int8Type(), 0))
fn := newValue(llfn, instr.Fn.(*ssa.Function).Signature)
bindings := make([]*govalue, len(instr.Bindings))
for i, binding := range instr.Bindings {
bindings[i] = fr.value(binding)
}
fr.env[instr] = fr.makeClosure(fn, bindings)
case *ssa.MakeInterface:
// fr.ptr[instr.X] will be set if a pointer load was elided by canAvoidLoad
if ptr, ok := fr.ptr[instr.X]; ok {
fr.env[instr] = fr.makeInterfaceFromPointer(ptr, instr.X.Type(), instr.Type())
} else {
receiver := fr.llvmvalue(instr.X)
fr.env[instr] = fr.makeInterface(receiver, instr.X.Type(), 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.tuples[instr.Iter]
if instr.IsString {
fr.tuples[instr] = fr.stringIterNext(iter)
} else {
fr.tuples[instr] = fr.mapIterNext(iter)
}
case *ssa.Panic:
arg := fr.value(instr.X)
fr.callPanic(arg)
case *ssa.Phi:
typ := instr.Type()
phi := fr.builder.CreatePHI(fr.llvmtypes.ToLLVM(typ), instr.Comment)
fr.env[instr] = newValue(phi, typ)
fr.phis = append(fr.phis, pendingPhi{instr, phi})
case *ssa.Range:
x := fr.value(instr.X)
switch x.Type().Underlying().(type) {
case *types.Map:
fr.tuples[instr] = fr.mapIterInit(x)
case *types.Basic: // string
fr.tuples[instr] = fr.stringIterInit(x)
default:
panic(fmt.Sprintf("unhandled range for type %T", x.Type()))
}
case *ssa.Return:
vals := make([]llvm.Value, len(instr.Results))
for i, res := range instr.Results {
vals[i] = fr.llvmvalue(res)
}
fr.retInf.encode(llvm.GlobalContext(), fr.allocaBuilder, fr.builder, vals)
case *ssa.RunDefers:
fr.runDefers()
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),
}
}
index, recvOk, recvElems := fr.chanSelect(states, instr.Blocking)
tuple := append([]*govalue{index, recvOk}, recvElems...)
fr.tuples[instr] = tuple
case *ssa.Send:
fr.chanSend(fr.value(instr.Chan), fr.value(instr.X))
case *ssa.Slice:
x := fr.llvmvalue(instr.X)
low := fr.llvmvalue(instr.Low)
high := fr.llvmvalue(instr.High)
max := fr.llvmvalue(instr.Max)
slice := fr.slice(x, instr.X.Type(), low, high, max)
fr.env[instr] = newValue(slice, instr.Type())
case *ssa.Store:
addr := fr.llvmvalue(instr.Addr)
value := fr.llvmvalue(instr.Val)
addr = fr.builder.CreateBitCast(addr, llvm.PointerType(value.Type(), 0), "")
// If this is the init function, see if we can simulate the effect
// of the store in a global's initializer, in which case we can avoid
// generating code for it.
if !fr.isInit || !fr.maybeStoreInInitializer(value, addr) {
fr.nilCheck(instr.Addr, addr)
fr.builder.CreateStore(value, addr)
}
case *ssa.TypeAssert:
x := fr.value(instr.X)
if instr.CommaOk {
v, ok := fr.interfaceTypeCheck(x, instr.AssertedType)
fr.tuples[instr] = []*govalue{v, ok}
} else {
fr.env[instr] = fr.interfaceTypeAssert(x, instr.AssertedType)
}
case *ssa.UnOp:
operand := fr.value(instr.X)
switch instr.Op {
case token.ARROW:
x, ok := fr.chanRecv(operand, instr.CommaOk)
if instr.CommaOk {
fr.tuples[instr] = []*govalue{x, ok}
} else {
fr.env[instr] = x
}
case token.MUL:
fr.nilCheck(instr.X, operand.value)
if !fr.canAvoidLoad(instr, operand.value) {
// The bitcast is necessary to handle recursive pointer loads.
llptr := fr.builder.CreateBitCast(operand.value, llvm.PointerType(fr.llvmtypes.ToLLVM(instr.Type()), 0), "")
fr.env[instr] = newValue(fr.builder.CreateLoad(llptr, ""), instr.Type())
}
default:
fr.env[instr] = fr.unaryOp(operand, instr.Op)
}
default:
panic(fmt.Sprintf("unhandled: %v", instr))
}
}
func (u *unit) defineFunction(f *ssa.Function) {
// Only define functions from this package, or synthetic
// wrappers (which do not have a package).
if f.Pkg != nil && f.Pkg != u.pkg {
return
}
llfn := u.resolveFunctionGlobal(f)
linkage := u.getFunctionLinkage(f)
isMethod := f.Signature.Recv() != nil
// Methods cannot be referred to via a descriptor.
if !isMethod {
llfd := u.resolveFunctionDescriptorGlobal(f)
llfd.SetInitializer(llvm.ConstBitCast(llfn, llvm.PointerType(llvm.Int8Type(), 0)))
llfd.SetLinkage(linkage)
}
// We only need to emit a descriptor for functions without bodies.
if len(f.Blocks) == 0 {
return
}
ssaopt.LowerAllocsToStack(f)
if u.DumpSSA {
f.WriteTo(os.Stderr)
}
fr := newFrame(u, llfn)
defer fr.dispose()
fr.addCommonFunctionAttrs(fr.function)
fr.function.SetLinkage(linkage)
fr.logf("Define function: %s", f.String())
fti := u.llvmtypes.getSignatureInfo(f.Signature)
delete(u.undefinedFuncs, f)
fr.retInf = fti.retInf
// Push the compile unit and function onto the debug context.
if u.GenerateDebug {
u.debug.PushFunction(fr.function, f.Signature, f.Pos())
defer u.debug.PopFunction()
u.debug.SetLocation(fr.builder, f.Pos())
}
// If a function calls recover, we create a separate function to
// hold the real function, and this function calls __go_can_recover
// and bridges to it.
if callsRecover(f) {
fr = fr.bridgeRecoverFunc(fr.function, fti)
}
fr.blocks = make([]llvm.BasicBlock, len(f.Blocks))
fr.lastBlocks = make([]llvm.BasicBlock, len(f.Blocks))
for i, block := range f.Blocks {
fr.blocks[i] = llvm.AddBasicBlock(fr.function, fmt.Sprintf(".%d.%s", i, block.Comment))
}
fr.builder.SetInsertPointAtEnd(fr.blocks[0])
prologueBlock := llvm.InsertBasicBlock(fr.blocks[0], "prologue")
fr.builder.SetInsertPointAtEnd(prologueBlock)
// Map parameter positions to indices. We use this
// when processing locals to map back to parameters
// when generating debug metadata.
paramPos := make(map[token.Pos]int)
for i, param := range f.Params {
paramPos[param.Pos()] = i
llparam := fti.argInfos[i].decode(llvm.GlobalContext(), fr.builder, fr.builder)
if isMethod && i == 0 {
if _, ok := param.Type().Underlying().(*types.Pointer); !ok {
llparam = fr.builder.CreateBitCast(llparam, llvm.PointerType(fr.types.ToLLVM(param.Type()), 0), "")
llparam = fr.builder.CreateLoad(llparam, "")
}
}
fr.env[param] = newValue(llparam, param.Type())
}
// Load closure, extract free vars.
if len(f.FreeVars) > 0 {
for _, fv := range f.FreeVars {
fr.env[fv] = newValue(llvm.ConstNull(u.llvmtypes.ToLLVM(fv.Type())), fv.Type())
}
elemTypes := make([]llvm.Type, len(f.FreeVars)+1)
elemTypes[0] = llvm.PointerType(llvm.Int8Type(), 0) // function pointer
for i, fv := range f.FreeVars {
elemTypes[i+1] = u.llvmtypes.ToLLVM(fv.Type())
}
structType := llvm.StructType(elemTypes, false)
closure := fr.runtime.getClosure.call(fr)[0]
closure = fr.builder.CreateBitCast(closure, llvm.PointerType(structType, 0), "")
for i, fv := range f.FreeVars {
ptr := fr.builder.CreateStructGEP(closure, i+1, "")
ptr = fr.builder.CreateLoad(ptr, "")
fr.env[fv] = newValue(ptr, fv.Type())
}
}
// Allocate stack space for locals in the prologue block.
for _, local := range f.Locals {
typ := fr.llvmtypes.ToLLVM(deref(local.Type()))
alloca := fr.builder.CreateAlloca(typ, local.Comment)
fr.memsetZero(alloca, llvm.SizeOf(typ))
bcalloca := fr.builder.CreateBitCast(alloca, llvm.PointerType(llvm.Int8Type(), 0), "")
value := newValue(bcalloca, local.Type())
fr.env[local] = value
if fr.GenerateDebug {
paramIndex, ok := paramPos[local.Pos()]
if !ok {
paramIndex = -1
}
fr.debug.Declare(fr.builder, local, alloca, paramIndex)
}
}
// If this is the "init" function, enable init-specific optimizations.
if !isMethod && f.Name() == "init" {
fr.isInit = true
}
// If the function contains any defers, we must first create
// an unwind block. We can short-circuit the check for defers with
// f.Recover != nil.
if f.Recover != nil || hasDefer(f) {
fr.unwindBlock = llvm.AddBasicBlock(fr.function, "")
fr.frameptr = fr.builder.CreateAlloca(llvm.Int8Type(), "")
}
term := fr.builder.CreateBr(fr.blocks[0])
fr.allocaBuilder.SetInsertPointBefore(term)
for _, block := range f.DomPreorder() {
fr.translateBlock(block, fr.blocks[block.Index])
}
fr.fixupPhis()
if !fr.unwindBlock.IsNil() {
fr.setupUnwindBlock(f.Recover, f.Signature.Results())
}
// The init function needs to register the GC roots first. We do this
// after generating code for it because allocations may have caused
// additional GC roots to be created.
if fr.isInit {
fr.builder.SetInsertPointBefore(prologueBlock.FirstInstruction())
fr.registerGcRoots()
}
}