Initial commit of llgo.

llvm-svn: 222857
diff --git a/llgo/irgen/builtins.go b/llgo/irgen/builtins.go
new file mode 100644
index 0000000..404962f
--- /dev/null
+++ b/llgo/irgen/builtins.go
@@ -0,0 +1,116 @@
+//===- builtins.go - IR generation for builtins ---------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements IR generation for the built-in functions.
+//
+//===----------------------------------------------------------------------===//
+
+package irgen
+
+import (
+	"llvm.org/llgo/third_party/go.tools/go/types"
+	"llvm.org/llvm/bindings/go/llvm"
+)
+
+func (fr *frame) callCap(arg *govalue) *govalue {
+	var v llvm.Value
+	switch typ := arg.Type().Underlying().(type) {
+	case *types.Array:
+		v = llvm.ConstInt(fr.llvmtypes.inttype, uint64(typ.Len()), false)
+	case *types.Pointer:
+		atyp := typ.Elem().Underlying().(*types.Array)
+		v = llvm.ConstInt(fr.llvmtypes.inttype, uint64(atyp.Len()), false)
+	case *types.Slice:
+		v = fr.builder.CreateExtractValue(arg.value, 2, "")
+	case *types.Chan:
+		v = fr.runtime.chanCap.call(fr, arg.value)[0]
+	}
+	return newValue(v, types.Typ[types.Int])
+}
+
+func (fr *frame) callLen(arg *govalue) *govalue {
+	var lenvalue llvm.Value
+	switch typ := arg.Type().Underlying().(type) {
+	case *types.Array:
+		lenvalue = llvm.ConstInt(fr.llvmtypes.inttype, uint64(typ.Len()), false)
+	case *types.Pointer:
+		atyp := typ.Elem().Underlying().(*types.Array)
+		lenvalue = llvm.ConstInt(fr.llvmtypes.inttype, uint64(atyp.Len()), false)
+	case *types.Slice:
+		lenvalue = fr.builder.CreateExtractValue(arg.value, 1, "")
+	case *types.Map:
+		lenvalue = fr.runtime.mapLen.call(fr, arg.value)[0]
+	case *types.Basic:
+		if isString(typ) {
+			lenvalue = fr.builder.CreateExtractValue(arg.value, 1, "")
+		}
+	case *types.Chan:
+		lenvalue = fr.runtime.chanLen.call(fr, arg.value)[0]
+	}
+	return newValue(lenvalue, types.Typ[types.Int])
+}
+
+// callAppend takes two slices of the same type, and yields
+// the result of appending the second to the first.
+func (fr *frame) callAppend(a, b *govalue) *govalue {
+	bptr := fr.builder.CreateExtractValue(b.value, 0, "")
+	blen := fr.builder.CreateExtractValue(b.value, 1, "")
+	elemsizeInt64 := fr.types.Sizeof(a.Type().Underlying().(*types.Slice).Elem())
+	elemsize := llvm.ConstInt(fr.target.IntPtrType(), uint64(elemsizeInt64), false)
+	result := fr.runtime.append.call(fr, a.value, bptr, blen, elemsize)[0]
+	return newValue(result, a.Type())
+}
+
+// callCopy takes two slices a and b of the same type, and
+// yields the result of calling "copy(a, b)".
+func (fr *frame) callCopy(dest, source *govalue) *govalue {
+	aptr := fr.builder.CreateExtractValue(dest.value, 0, "")
+	alen := fr.builder.CreateExtractValue(dest.value, 1, "")
+	bptr := fr.builder.CreateExtractValue(source.value, 0, "")
+	blen := fr.builder.CreateExtractValue(source.value, 1, "")
+	aless := fr.builder.CreateICmp(llvm.IntULT, alen, blen, "")
+	minlen := fr.builder.CreateSelect(aless, alen, blen, "")
+	elemsizeInt64 := fr.types.Sizeof(dest.Type().Underlying().(*types.Slice).Elem())
+	elemsize := llvm.ConstInt(fr.types.inttype, uint64(elemsizeInt64), false)
+	bytes := fr.builder.CreateMul(minlen, elemsize, "")
+	fr.runtime.copy.call(fr, aptr, bptr, bytes)
+	return newValue(minlen, types.Typ[types.Int])
+}
+
+func (fr *frame) callRecover(isDeferredRecover bool) *govalue {
+	startbb := fr.builder.GetInsertBlock()
+	recoverbb := llvm.AddBasicBlock(fr.function, "")
+	contbb := llvm.AddBasicBlock(fr.function, "")
+	canRecover := fr.builder.CreateTrunc(fr.canRecover, llvm.Int1Type(), "")
+	fr.builder.CreateCondBr(canRecover, recoverbb, contbb)
+
+	fr.builder.SetInsertPointAtEnd(recoverbb)
+	var recovered llvm.Value
+	if isDeferredRecover {
+		recovered = fr.runtime.deferredRecover.call(fr)[0]
+	} else {
+		recovered = fr.runtime.recover.call(fr)[0]
+	}
+	recoverbb = fr.builder.GetInsertBlock()
+	fr.builder.CreateBr(contbb)
+
+	fr.builder.SetInsertPointAtEnd(contbb)
+	eface := types.NewInterface(nil, nil)
+	llv := fr.builder.CreatePHI(fr.types.ToLLVM(eface), "")
+	llv.AddIncoming(
+		[]llvm.Value{llvm.ConstNull(llv.Type()), recovered},
+		[]llvm.BasicBlock{startbb, recoverbb},
+	)
+	return newValue(llv, eface)
+}
+
+func (fr *frame) callPanic(arg *govalue) {
+	fr.runtime.panic.call(fr, arg.value)
+	fr.builder.CreateUnreachable()
+}