diff --git a/gossa/decl.go b/ssa/decl.go
similarity index 98%
rename from gossa/decl.go
rename to ssa/decl.go
index e6f05579..4d460dc3 100644
--- a/gossa/decl.go
+++ b/ssa/decl.go
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package gossa
+package ssa
 
 import (
 	"github.com/goplus/llvm"
diff --git a/gossa/func.go b/ssa/func.go
similarity index 99%
rename from gossa/func.go
rename to ssa/func.go
index e1c2a226..13ef513a 100644
--- a/gossa/func.go
+++ b/ssa/func.go
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package gossa
+package ssa
 
 // Function represents the parameters, results, and code of a function
 // or method.
diff --git a/gossa/package.go b/ssa/package.go
similarity index 78%
rename from gossa/package.go
rename to ssa/package.go
index e6a1b01e..66908f47 100644
--- a/gossa/package.go
+++ b/ssa/package.go
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package gossa
+package ssa
 
 import (
 	"go/constant"
@@ -30,7 +30,10 @@ import (
 type Program struct {
 	ctx  llvm.Context
 	typs typeutil.Map
-	td   llvm.TargetData
+
+	target *Target
+	td     llvm.TargetData
+	tm     llvm.TargetMachine
 
 	intType   llvm.Type
 	int8Type  llvm.Type
@@ -39,11 +42,14 @@ type Program struct {
 	int64Type llvm.Type
 }
 
-func NewProgram(targetRep string) *Program {
+func NewProgram(target *Target) *Program {
+	if target == nil {
+		target = &Target{}
+	}
 	ctx := llvm.NewContext()
 	ctx.Finalize()
-	td := llvm.NewTargetData(targetRep)
-	return &Program{ctx: ctx, td: td}
+	td := llvm.NewTargetData("") // TODO(xsw): target config
+	return &Program{ctx: ctx, target: target, td: td}
 }
 
 func (p *Program) NewPackage(name, pkgPath string) *Package {
@@ -82,7 +88,24 @@ func (p *Package) NewFunc(name string, sig *types.Signature) *Function {
 	return &Function{}
 }
 
-func (p *Package) Bytes() []byte {
+type CodeGenFileType = llvm.CodeGenFileType
+
+const (
+	AssemblyFile = llvm.AssemblyFile
+	ObjectFile   = llvm.ObjectFile
+)
+
+func (p *Package) CodeGen(ft CodeGenFileType) (ret []byte, err error) {
+	buf, err := p.prog.targetMachine().EmitToMemoryBuffer(p.mod, ft)
+	if err != nil {
+		return
+	}
+	ret = buf.Bytes()
+	buf.Dispose()
+	return
+}
+
+func (p *Package) Bitcode() []byte {
 	buf := llvm.WriteBitcodeToMemoryBuffer(p.mod)
 	ret := buf.Bytes()
 	buf.Dispose()
@@ -90,7 +113,7 @@ func (p *Package) Bytes() []byte {
 }
 
 func (p *Package) WriteTo(w io.Writer) (int64, error) {
-	n, err := w.Write(p.Bytes())
+	n, err := w.Write(p.Bitcode())
 	return int64(n), err
 }
 
diff --git a/gossa/gossa_test.go b/ssa/ssa_test.go
similarity index 82%
rename from gossa/gossa_test.go
rename to ssa/ssa_test.go
index 63391891..bd5070a9 100644
--- a/gossa/gossa_test.go
+++ b/ssa/ssa_test.go
@@ -14,28 +14,25 @@
  * limitations under the License.
  */
 
-package gossa
+package ssa
 
 import (
 	"go/types"
 	"testing"
-
-	"github.com/goplus/llvm"
 )
 
 func assertPkg(t *testing.T, p *Package) {
-	ctx := llvm.NewContext()
-	buf := llvm.WriteBitcodeToMemoryBuffer(p.mod)
-	mod, err := ctx.ParseIR(buf)
-	// buf.Dispose()
+	b, err := p.CodeGen(AssemblyFile)
 	if err != nil {
 		t.Fatal("ctx.ParseIR:", err)
 	}
-	_ = mod
+	if v := string(b); v != "" {
+		t.Log(v)
+	}
 }
 
 func TestVar(t *testing.T) {
-	prog := NewProgram("")
+	prog := NewProgram(nil)
 	pkg := prog.NewPackage("foo", "foo")
 	pkg.NewVar("a", types.Typ[types.Int])
 	assertPkg(t, pkg)
diff --git a/ssa/target.go b/ssa/target.go
new file mode 100644
index 00000000..1154f10c
--- /dev/null
+++ b/ssa/target.go
@@ -0,0 +1,152 @@
+/*
+ * Copyright (c) 2024 The GoPlus Authors (goplus.org). All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ssa
+
+import (
+	"runtime"
+
+	"github.com/goplus/llvm"
+)
+
+func init() {
+	llvm.InitializeAllTargetInfos()
+	llvm.InitializeAllTargets()
+	llvm.InitializeAllTargetMCs()
+	llvm.InitializeAllAsmParsers()
+	llvm.InitializeAllAsmPrinters()
+}
+
+type Target struct {
+	GOOS   string
+	GOARCH string
+	GOARM  string // "5", "6", "7" (default)
+}
+
+func (p *Program) targetMachine() llvm.TargetMachine {
+	if p.tm.C == nil {
+		spec := p.target.toSpec()
+		target, err := llvm.GetTargetFromTriple(spec.triple)
+		if err != nil {
+			panic(err)
+		}
+		p.tm = target.CreateTargetMachine(
+			spec.triple,
+			spec.cpu,
+			spec.features,
+			llvm.CodeGenLevelDefault,
+			llvm.RelocDefault,
+			llvm.CodeModelDefault,
+		)
+	}
+	return p.tm
+}
+
+type targetSpec struct {
+	triple   string
+	cpu      string
+	features string
+}
+
+func (p *Target) toSpec() (spec targetSpec) {
+	// Configure based on GOOS/GOARCH environment variables (falling back to
+	// runtime.GOOS/runtime.GOARCH), and generate a LLVM target based on it.
+	var llvmarch string
+	var goarch = p.GOARCH
+	var goos = p.GOOS
+	if goarch == "" {
+		goarch = runtime.GOARCH
+	}
+	if goos == "" {
+		goos = runtime.GOOS
+	}
+	switch goarch {
+	case "386":
+		llvmarch = "i386"
+	case "amd64":
+		llvmarch = "x86_64"
+	case "arm64":
+		llvmarch = "aarch64"
+	case "arm":
+		switch p.GOARM {
+		case "5":
+			llvmarch = "armv5"
+		case "6":
+			llvmarch = "armv6"
+		default:
+			llvmarch = "armv7"
+		}
+	case "wasm":
+		llvmarch = "wasm32"
+	default:
+		llvmarch = goarch
+	}
+	llvmvendor := "unknown"
+	llvmos := goos
+	switch goos {
+	case "darwin":
+		// Use macosx* instead of darwin, otherwise darwin/arm64 will refer
+		// to iOS!
+		llvmos = "macosx10.12.0"
+		if llvmarch == "aarch64" {
+			// Looks like Apple prefers to call this architecture ARM64
+			// instead of AArch64.
+			llvmarch = "arm64"
+			llvmos = "macosx11.0.0"
+		}
+		llvmvendor = "apple"
+	case "wasip1":
+		llvmos = "wasi"
+	}
+	// Target triples (which actually have four components, but are called
+	// triples for historical reasons) have the form:
+	//   arch-vendor-os-environment
+	spec.triple = llvmarch + "-" + llvmvendor + "-" + llvmos
+	if llvmos == "windows" {
+		spec.triple += "-gnu"
+	} else if goarch == "arm" {
+		spec.triple += "-gnueabihf"
+	}
+	switch goarch {
+	case "386":
+		spec.cpu = "pentium4"
+		spec.features = "+cx8,+fxsr,+mmx,+sse,+sse2,+x87"
+	case "amd64":
+		spec.cpu = "x86-64"
+		spec.features = "+cx8,+fxsr,+mmx,+sse,+sse2,+x87"
+	case "arm":
+		spec.cpu = "generic"
+		switch llvmarch {
+		case "armv5":
+			spec.features = "+armv5t,+strict-align,-aes,-bf16,-d32,-dotprod,-fp-armv8,-fp-armv8d16,-fp-armv8d16sp,-fp-armv8sp,-fp16,-fp16fml,-fp64,-fpregs,-fullfp16,-mve.fp,-neon,-sha2,-thumb-mode,-vfp2,-vfp2sp,-vfp3,-vfp3d16,-vfp3d16sp,-vfp3sp,-vfp4,-vfp4d16,-vfp4d16sp,-vfp4sp"
+		case "armv6":
+			spec.features = "+armv6,+dsp,+fp64,+strict-align,+vfp2,+vfp2sp,-aes,-d32,-fp-armv8,-fp-armv8d16,-fp-armv8d16sp,-fp-armv8sp,-fp16,-fp16fml,-fullfp16,-neon,-sha2,-thumb-mode,-vfp3,-vfp3d16,-vfp3d16sp,-vfp3sp,-vfp4,-vfp4d16,-vfp4d16sp,-vfp4sp"
+		case "armv7":
+			spec.features = "+armv7-a,+d32,+dsp,+fp64,+neon,+vfp2,+vfp2sp,+vfp3,+vfp3d16,+vfp3d16sp,+vfp3sp,-aes,-fp-armv8,-fp-armv8d16,-fp-armv8d16sp,-fp-armv8sp,-fp16,-fp16fml,-fullfp16,-sha2,-thumb-mode,-vfp4,-vfp4d16,-vfp4d16sp,-vfp4sp"
+		}
+	case "arm64":
+		spec.cpu = "generic"
+		if goos == "darwin" {
+			spec.features = "+neon"
+		} else { // windows, linux
+			spec.features = "+neon,-fmv"
+		}
+	case "wasm":
+		spec.cpu = "generic"
+		spec.features = "+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext"
+	}
+	return
+}
diff --git a/gossa/type.go b/ssa/type.go
similarity index 99%
rename from gossa/type.go
rename to ssa/type.go
index af1e92b6..270561aa 100644
--- a/gossa/type.go
+++ b/ssa/type.go
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package gossa
+package ssa
 
 import (
 	"go/types"