Example #1
0
File: ssa.go Project: hinike/llgo
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))
	}
}
Example #2
0
func visitInst(inst ssa.Instruction, fr *frame) {
	switch inst := inst.(type) {
	case *ssa.MakeChan:
		visitMakeChan(inst, fr)

	case *ssa.Send:
		visitSend(inst, fr)

	case *ssa.UnOp:
		switch inst.Op {
		case token.ARROW:
			visitRecv(inst, fr)
		case token.MUL:
			visitDeref(inst, fr)
		default:
			fmt.Fprintf(os.Stderr, "   # unhandled %s = %s\n", red(inst.Name()), red(inst.String()))
		}

	case *ssa.Call:
		visitCall(inst, fr)

	case *ssa.Extract:
		visitExtract(inst, fr)

	case *ssa.Go:
		fr.callGo(inst)

	case *ssa.Return:
		fr.retvals = visitReturn(inst, fr)

	case *ssa.Store:
		visitStore(inst, fr)

	case *ssa.Alloc:
		visitAlloc(inst, fr)

	case *ssa.MakeClosure:
		visitMakeClosure(inst, fr)

	case *ssa.Select:
		visitSelect(inst, fr)

	case *ssa.ChangeType:
		visitChangeType(inst, fr)

	case *ssa.ChangeInterface:
		visitChangeInterface(inst, fr)

	case *ssa.If:
		visitIf(inst, fr)

	case *ssa.Jump:
		visitJump(inst, fr)

	case *ssa.BinOp:
		visitBinOp(inst, fr)

	case *ssa.Slice:
		visitSlice(inst, fr)

	case *ssa.MakeSlice:
		visitMakeSlice(inst, fr)

	case *ssa.FieldAddr:
		visitFieldAddr(inst, fr)

	case *ssa.Field:
		visitField(inst, fr)

	case *ssa.IndexAddr:
		visitIndexAddr(inst, fr)

	case *ssa.Index:
		visitIndex(inst, fr)

	case *ssa.Defer:
		visitDefer(inst, fr)

	case *ssa.RunDefers:
		visitRunDefers(inst, fr)

	case *ssa.Phi:
		visitPhi(inst, fr)

	case *ssa.TypeAssert:
		visitTypeAssert(inst, fr)

	case *ssa.MakeInterface:
		visitMakeInterface(inst, fr)

	case *ssa.DebugRef:

	default:
		// Everything else not handled yet
		if v, ok := inst.(ssa.Value); ok {
			fmt.Fprintf(os.Stderr, "   # unhandled %s = %s\n", red(v.Name()), red(v.String()))
		} else {
			fmt.Fprintf(os.Stderr, "   # unhandled %s\n", red(inst.String()))
		}
	}
}