From f1bb42f5543f646d008a54397bde6311caf7f5c7 Mon Sep 17 00:00:00 2001
From: xushiwei <x@goplus.org>
Date: Fri, 3 May 2024 23:10:02 +0800
Subject: [PATCH] llgo/ssa: SizeOf, MakeSlice, VoidPtr

---
 cl/_testdata/index/out.ll             | 130 -------
 cl/_testrt/_intgen/in.go              |  20 +
 cl/_testrt/_intgen/out.ll             |   0
 cl/_testrt/builtin/out.ll             |   8 +-
 cl/_testrt/concat/out.ll              |   4 +-
 cl/_testrt/gblarray/out.ll            |   4 +-
 cl/{_testdata => _testrt}/index/in.go |   0
 cl/_testrt/index/out.ll               | 138 +++++++
 cl/_testrt/qsort/out.ll               |   4 +-
 cl/_testrt/struct/out.ll              |  30 +-
 cl/_testrt/sum/out.ll                 |   4 +-
 cl/_testrt/typalias/out.ll            |   4 +-
 cl/compile.go                         |  22 +-
 internal/runtime/llgo_autogen.ll      | 522 ++++++++++++++------------
 internal/runtime/z_c.go               |  15 +-
 internal/runtime/z_slice.go           |  28 +-
 internal/runtime/z_string.go          |   4 +-
 ssa/expr.go                           |  83 ++--
 ssa/package.go                        |  30 +-
 ssa/type.go                           |  12 +-
 20 files changed, 595 insertions(+), 467 deletions(-)
 delete mode 100644 cl/_testdata/index/out.ll
 create mode 100644 cl/_testrt/_intgen/in.go
 create mode 100644 cl/_testrt/_intgen/out.ll
 rename cl/{_testdata => _testrt}/index/in.go (100%)
 create mode 100644 cl/_testrt/index/out.ll

diff --git a/cl/_testdata/index/out.ll b/cl/_testdata/index/out.ll
deleted file mode 100644
index 5a7e3d7a..00000000
--- a/cl/_testdata/index/out.ll
+++ /dev/null
@@ -1,130 +0,0 @@
-; ModuleID = 'main'
-source_filename = "main"
-
-%main.point = type { i64, i64 }
-%"github.com/goplus/llgo/internal/runtime.String" = type { ptr, i64 }
-
-@"main.init$guard" = global ptr null
-@0 = private unnamed_addr constant [7 x i8] c"%d %d\0A\00", align 1
-@1 = private unnamed_addr constant [7 x i8] c"%d %d\0A\00", align 1
-@2 = private unnamed_addr constant [4 x i8] c"%d\0A\00", align 1
-@3 = private unnamed_addr constant [4 x i8] c"%d\0A\00", align 1
-@4 = private unnamed_addr constant [4 x i8] c"%c\0A\00", align 1
-@5 = private unnamed_addr constant [7 x i8] c"123456\00", align 1
-@6 = private unnamed_addr constant [4 x i8] c"%c\0A\00", align 1
-@7 = private unnamed_addr constant [7 x i8] c"123456\00", align 1
-
-define void @main.init() {
-_llgo_0:
-  %0 = load i1, ptr @"main.init$guard", align 1
-  br i1 %0, label %_llgo_2, label %_llgo_1
-
-_llgo_1:                                          ; preds = %_llgo_0
-  store i1 true, ptr @"main.init$guard", align 1
-  br label %_llgo_2
-
-_llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
-  ret void
-}
-
-define void @main() {
-_llgo_0:
-  call void @"github.com/goplus/llgo/internal/runtime.init"()
-  call void @main.init()
-  %0 = alloca %main.point, align 8
-  %1 = alloca [3 x %main.point], align 8
-  %2 = getelementptr inbounds %main.point, ptr %1, i64 0
-  %3 = getelementptr inbounds %main.point, ptr %2, i32 0, i32 0
-  %4 = getelementptr inbounds %main.point, ptr %2, i32 0, i32 1
-  %5 = getelementptr inbounds %main.point, ptr %1, i64 1
-  %6 = getelementptr inbounds %main.point, ptr %5, i32 0, i32 0
-  %7 = getelementptr inbounds %main.point, ptr %5, i32 0, i32 1
-  %8 = getelementptr inbounds %main.point, ptr %1, i64 2
-  %9 = getelementptr inbounds %main.point, ptr %8, i32 0, i32 0
-  %10 = getelementptr inbounds %main.point, ptr %8, i32 0, i32 1
-  store i64 1, ptr %3, align 4
-  store i64 2, ptr %4, align 4
-  store i64 3, ptr %6, align 4
-  store i64 4, ptr %7, align 4
-  store i64 5, ptr %9, align 4
-  store i64 6, ptr %10, align 4
-  %11 = load [3 x %main.point], ptr %1, align 4
-  %12 = getelementptr inbounds %main.point, ptr %1, i64 2
-  %13 = load %main.point, ptr %12, align 4
-  store %main.point %13, ptr %0, align 4
-  %14 = getelementptr inbounds %main.point, ptr %0, i32 0, i32 0
-  %15 = load i64, ptr %14, align 4
-  %16 = getelementptr inbounds %main.point, ptr %0, i32 0, i32 1
-  %17 = load i64, ptr %16, align 4
-  %18 = call i32 (ptr, ...) @printf(ptr @0, i64 %15, i64 %17)
-  %19 = alloca [2 x i64], align 8
-  %20 = alloca [2 x [2 x i64]], align 8
-  %21 = getelementptr inbounds [2 x i64], ptr %20, i64 0
-  %22 = getelementptr inbounds i64, ptr %21, i64 0
-  %23 = getelementptr inbounds i64, ptr %21, i64 1
-  %24 = getelementptr inbounds [2 x i64], ptr %20, i64 1
-  %25 = getelementptr inbounds i64, ptr %24, i64 0
-  %26 = getelementptr inbounds i64, ptr %24, i64 1
-  store i64 1, ptr %22, align 4
-  store i64 2, ptr %23, align 4
-  store i64 3, ptr %25, align 4
-  store i64 4, ptr %26, align 4
-  %27 = load [2 x [2 x i64]], ptr %20, align 4
-  %28 = getelementptr inbounds [2 x i64], ptr %20, i64 1
-  %29 = load [2 x i64], ptr %28, align 4
-  store [2 x i64] %29, ptr %19, align 4
-  %30 = getelementptr inbounds i64, ptr %19, i64 0
-  %31 = load i64, ptr %30, align 4
-  %32 = getelementptr inbounds i64, ptr %19, i64 1
-  %33 = load i64, ptr %32, align 4
-  %34 = call i32 (ptr, ...) @printf(ptr @1, i64 %31, i64 %33)
-  %35 = alloca [5 x i64], align 8
-  %36 = getelementptr inbounds i64, ptr %35, i64 0
-  %37 = getelementptr inbounds i64, ptr %35, i64 1
-  %38 = getelementptr inbounds i64, ptr %35, i64 2
-  %39 = getelementptr inbounds i64, ptr %35, i64 3
-  %40 = getelementptr inbounds i64, ptr %35, i64 4
-  store i64 1, ptr %36, align 4
-  store i64 2, ptr %37, align 4
-  store i64 3, ptr %38, align 4
-  store i64 4, ptr %39, align 4
-  store i64 5, ptr %40, align 4
-  %41 = load [5 x i64], ptr %35, align 4
-  %42 = getelementptr inbounds i64, ptr %35, i64 2
-  %43 = load i64, ptr %42, align 4
-  %44 = call i32 (ptr, ...) @printf(ptr @2, i64 %43)
-  %45 = alloca [5 x i64], align 8
-  %46 = getelementptr inbounds i64, ptr %45, i64 0
-  %47 = getelementptr inbounds i64, ptr %45, i64 1
-  %48 = getelementptr inbounds i64, ptr %45, i64 2
-  %49 = getelementptr inbounds i64, ptr %45, i64 3
-  %50 = getelementptr inbounds i64, ptr %45, i64 4
-  store i64 1, ptr %46, align 4
-  store i64 2, ptr %47, align 4
-  store i64 3, ptr %48, align 4
-  store i64 4, ptr %49, align 4
-  store i64 5, ptr %50, align 4
-  %51 = load [5 x i64], ptr %45, align 4
-  %52 = getelementptr inbounds i64, ptr %45, i64 2
-  %53 = load i64, ptr %52, align 4
-  %54 = call i32 (ptr, ...) @printf(ptr @3, i64 %53)
-  %55 = call %"github.com/goplus/llgo/internal/runtime.String" @"github.com/goplus/llgo/internal/runtime.NewString"(ptr @5, i64 6)
-  %56 = call ptr @"github.com/goplus/llgo/internal/runtime.StringData"(%"github.com/goplus/llgo/internal/runtime.String" %55)
-  %57 = getelementptr inbounds i8, ptr %56, i64 2
-  %58 = load i8, ptr %57, align 1
-  %59 = call i32 (ptr, ...) @printf(ptr @4, i8 %58)
-  %60 = call %"github.com/goplus/llgo/internal/runtime.String" @"github.com/goplus/llgo/internal/runtime.NewString"(ptr @7, i64 6)
-  %61 = call ptr @"github.com/goplus/llgo/internal/runtime.StringData"(%"github.com/goplus/llgo/internal/runtime.String" %60)
-  %62 = getelementptr inbounds i8, ptr %61, i64 1
-  %63 = load i8, ptr %62, align 1
-  %64 = call i32 (ptr, ...) @printf(ptr @6, i8 %63)
-  ret void
-}
-
-declare void @"github.com/goplus/llgo/internal/runtime.init"()
-
-declare i32 @printf(ptr, ...)
-
-declare %"github.com/goplus/llgo/internal/runtime.String" @"github.com/goplus/llgo/internal/runtime.NewString"(ptr, i64)
-
-declare ptr @"github.com/goplus/llgo/internal/runtime.StringData"(%"github.com/goplus/llgo/internal/runtime.String")
diff --git a/cl/_testrt/_intgen/in.go b/cl/_testrt/_intgen/in.go
new file mode 100644
index 00000000..a5e277d0
--- /dev/null
+++ b/cl/_testrt/_intgen/in.go
@@ -0,0 +1,20 @@
+package main
+
+import (
+	"github.com/goplus/llgo/internal/runtime/c"
+)
+
+func genInts(n int, gen func() c.Int) []c.Int {
+	a := make([]c.Int, n)
+	for i := range a {
+		a[i] = gen()
+	}
+	return a
+}
+
+func main() {
+	a := genInts(5, c.Rand)
+	for _, v := range a {
+		c.Printf(c.Str("%d\n"), v)
+	}
+}
diff --git a/cl/_testrt/_intgen/out.ll b/cl/_testrt/_intgen/out.ll
new file mode 100644
index 00000000..e69de29b
diff --git a/cl/_testrt/builtin/out.ll b/cl/_testrt/builtin/out.ll
index a48e9c94..389430c9 100644
--- a/cl/_testrt/builtin/out.ll
+++ b/cl/_testrt/builtin/out.ll
@@ -34,7 +34,7 @@ define void @main() {
 _llgo_0:
   call void @"github.com/goplus/llgo/internal/runtime.init"()
   call void @main.init()
-  %0 = call ptr @"github.com/goplus/llgo/internal/runtime.Alloc"(i64 32)
+  %0 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 32)
   %1 = getelementptr inbounds i64, ptr %0, i64 0
   store i64 1, ptr %1, align 4
   %2 = getelementptr inbounds i64, ptr %0, i64 1
@@ -44,7 +44,7 @@ _llgo_0:
   %4 = getelementptr inbounds i64, ptr %0, i64 3
   store i64 4, ptr %4, align 4
   %5 = call %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %0, i64 8, i64 4, i64 0, i64 4, i64 4)
-  %6 = call ptr @"github.com/goplus/llgo/internal/runtime.Alloc"(i64 32)
+  %6 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 32)
   %7 = getelementptr inbounds i64, ptr %6, i64 0
   %8 = getelementptr inbounds i64, ptr %6, i64 1
   %9 = getelementptr inbounds i64, ptr %6, i64 2
@@ -55,7 +55,7 @@ _llgo_0:
   store i64 4, ptr %10, align 4
   %11 = call i64 @"github.com/goplus/llgo/internal/runtime.SliceLen"(%"github.com/goplus/llgo/internal/runtime.Slice" %5)
   call void @main.out(i64 %11)
-  %12 = call ptr @"github.com/goplus/llgo/internal/runtime.Alloc"(i64 32)
+  %12 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 32)
   %13 = getelementptr inbounds i64, ptr %12, i64 0
   store i64 1, ptr %13, align 4
   %14 = getelementptr inbounds i64, ptr %12, i64 1
@@ -155,7 +155,7 @@ _llgo_0:
 
 declare void @"github.com/goplus/llgo/internal/runtime.init"()
 
-declare ptr @"github.com/goplus/llgo/internal/runtime.Alloc"(i64)
+declare ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64)
 
 declare %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr, i64, i64, i64, i64, i64)
 
diff --git a/cl/_testrt/concat/out.ll b/cl/_testrt/concat/out.ll
index 1fdae7e9..9cd7436a 100644
--- a/cl/_testrt/concat/out.ll
+++ b/cl/_testrt/concat/out.ll
@@ -64,7 +64,7 @@ define void @main() {
 _llgo_0:
   call void @"github.com/goplus/llgo/internal/runtime.init"()
   call void @main.init()
-  %0 = call ptr @"github.com/goplus/llgo/internal/runtime.Alloc"(i64 48)
+  %0 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 48)
   %1 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %0, i64 0
   %2 = call %"github.com/goplus/llgo/internal/runtime.String" @"github.com/goplus/llgo/internal/runtime.NewString"(ptr @1, i64 5)
   store %"github.com/goplus/llgo/internal/runtime.String" %2, ptr %1, align 8
@@ -95,7 +95,7 @@ declare %"github.com/goplus/llgo/internal/runtime.String" @"github.com/goplus/ll
 
 declare void @"github.com/goplus/llgo/internal/runtime.init"()
 
-declare ptr @"github.com/goplus/llgo/internal/runtime.Alloc"(i64)
+declare ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64)
 
 declare %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr, i64, i64, i64, i64, i64)
 
diff --git a/cl/_testrt/gblarray/out.ll b/cl/_testrt/gblarray/out.ll
index ab730de7..1a0221f8 100644
--- a/cl/_testrt/gblarray/out.ll
+++ b/cl/_testrt/gblarray/out.ll
@@ -18,7 +18,7 @@ _llgo_0:
 
 define ptr @main.basicType(i64 %0) {
 _llgo_0:
-  %1 = call ptr @"github.com/goplus/llgo/internal/runtime.Alloc"(i64 48)
+  %1 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 56)
   %2 = getelementptr inbounds %"github.com/goplus/llgo/internal/abi.Type", ptr %1, i32 0, i32 0
   %3 = getelementptr inbounds i64, ptr @main.sizeBasicTypes, i64 %0
   %4 = load i64, ptr %3, align 4
@@ -63,7 +63,7 @@ _llgo_0:
   ret void
 }
 
-declare ptr @"github.com/goplus/llgo/internal/runtime.Alloc"(i64)
+declare ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64)
 
 declare void @"github.com/goplus/llgo/internal/abi.init"()
 
diff --git a/cl/_testdata/index/in.go b/cl/_testrt/index/in.go
similarity index 100%
rename from cl/_testdata/index/in.go
rename to cl/_testrt/index/in.go
diff --git a/cl/_testrt/index/out.ll b/cl/_testrt/index/out.ll
new file mode 100644
index 00000000..1924727d
--- /dev/null
+++ b/cl/_testrt/index/out.ll
@@ -0,0 +1,138 @@
+; ModuleID = 'main'
+source_filename = "main"
+
+%main.point = type { i64, i64 }
+%"github.com/goplus/llgo/internal/runtime.String" = type { ptr, i64 }
+
+@"main.init$guard" = global ptr null
+@0 = private unnamed_addr constant [7 x i8] c"%d %d\0A\00", align 1
+@1 = private unnamed_addr constant [7 x i8] c"%d %d\0A\00", align 1
+@2 = private unnamed_addr constant [4 x i8] c"%d\0A\00", align 1
+@3 = private unnamed_addr constant [4 x i8] c"%d\0A\00", align 1
+@4 = private unnamed_addr constant [4 x i8] c"%c\0A\00", align 1
+@5 = private unnamed_addr constant [7 x i8] c"123456\00", align 1
+@6 = private unnamed_addr constant [4 x i8] c"%c\0A\00", align 1
+@7 = private unnamed_addr constant [7 x i8] c"123456\00", align 1
+
+define void @main.init() {
+_llgo_0:
+  %0 = load i1, ptr @"main.init$guard", align 1
+  br i1 %0, label %_llgo_2, label %_llgo_1
+
+_llgo_1:                                          ; preds = %_llgo_0
+  store i1 true, ptr @"main.init$guard", align 1
+  br label %_llgo_2
+
+_llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
+  ret void
+}
+
+define void @main() {
+_llgo_0:
+  call void @"github.com/goplus/llgo/internal/runtime.init"()
+  call void @main.init()
+  %0 = alloca %main.point, align 8
+  %1 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %0, i64 16)
+  %2 = alloca [3 x %main.point], align 8
+  %3 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %2, i64 48)
+  %4 = getelementptr inbounds %main.point, ptr %3, i64 0
+  %5 = getelementptr inbounds %main.point, ptr %4, i32 0, i32 0
+  %6 = getelementptr inbounds %main.point, ptr %4, i32 0, i32 1
+  %7 = getelementptr inbounds %main.point, ptr %3, i64 1
+  %8 = getelementptr inbounds %main.point, ptr %7, i32 0, i32 0
+  %9 = getelementptr inbounds %main.point, ptr %7, i32 0, i32 1
+  %10 = getelementptr inbounds %main.point, ptr %3, i64 2
+  %11 = getelementptr inbounds %main.point, ptr %10, i32 0, i32 0
+  %12 = getelementptr inbounds %main.point, ptr %10, i32 0, i32 1
+  store i64 1, ptr %5, align 4
+  store i64 2, ptr %6, align 4
+  store i64 3, ptr %8, align 4
+  store i64 4, ptr %9, align 4
+  store i64 5, ptr %11, align 4
+  store i64 6, ptr %12, align 4
+  %13 = load [3 x %main.point], ptr %3, align 4
+  %14 = getelementptr inbounds %main.point, ptr %3, i64 2
+  %15 = load %main.point, ptr %14, align 4
+  store %main.point %15, ptr %1, align 4
+  %16 = getelementptr inbounds %main.point, ptr %1, i32 0, i32 0
+  %17 = load i64, ptr %16, align 4
+  %18 = getelementptr inbounds %main.point, ptr %1, i32 0, i32 1
+  %19 = load i64, ptr %18, align 4
+  %20 = call i32 (ptr, ...) @printf(ptr @0, i64 %17, i64 %19)
+  %21 = alloca [2 x i64], align 8
+  %22 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %21, i64 16)
+  %23 = alloca [2 x [2 x i64]], align 8
+  %24 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %23, i64 32)
+  %25 = getelementptr inbounds [2 x i64], ptr %24, i64 0
+  %26 = getelementptr inbounds i64, ptr %25, i64 0
+  %27 = getelementptr inbounds i64, ptr %25, i64 1
+  %28 = getelementptr inbounds [2 x i64], ptr %24, i64 1
+  %29 = getelementptr inbounds i64, ptr %28, i64 0
+  %30 = getelementptr inbounds i64, ptr %28, i64 1
+  store i64 1, ptr %26, align 4
+  store i64 2, ptr %27, align 4
+  store i64 3, ptr %29, align 4
+  store i64 4, ptr %30, align 4
+  %31 = load [2 x [2 x i64]], ptr %24, align 4
+  %32 = getelementptr inbounds [2 x i64], ptr %24, i64 1
+  %33 = load [2 x i64], ptr %32, align 4
+  store [2 x i64] %33, ptr %22, align 4
+  %34 = getelementptr inbounds i64, ptr %22, i64 0
+  %35 = load i64, ptr %34, align 4
+  %36 = getelementptr inbounds i64, ptr %22, i64 1
+  %37 = load i64, ptr %36, align 4
+  %38 = call i32 (ptr, ...) @printf(ptr @1, i64 %35, i64 %37)
+  %39 = alloca [5 x i64], align 8
+  %40 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %39, i64 40)
+  %41 = getelementptr inbounds i64, ptr %40, i64 0
+  %42 = getelementptr inbounds i64, ptr %40, i64 1
+  %43 = getelementptr inbounds i64, ptr %40, i64 2
+  %44 = getelementptr inbounds i64, ptr %40, i64 3
+  %45 = getelementptr inbounds i64, ptr %40, i64 4
+  store i64 1, ptr %41, align 4
+  store i64 2, ptr %42, align 4
+  store i64 3, ptr %43, align 4
+  store i64 4, ptr %44, align 4
+  store i64 5, ptr %45, align 4
+  %46 = load [5 x i64], ptr %40, align 4
+  %47 = getelementptr inbounds i64, ptr %40, i64 2
+  %48 = load i64, ptr %47, align 4
+  %49 = call i32 (ptr, ...) @printf(ptr @2, i64 %48)
+  %50 = alloca [5 x i64], align 8
+  %51 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %50, i64 40)
+  %52 = getelementptr inbounds i64, ptr %51, i64 0
+  %53 = getelementptr inbounds i64, ptr %51, i64 1
+  %54 = getelementptr inbounds i64, ptr %51, i64 2
+  %55 = getelementptr inbounds i64, ptr %51, i64 3
+  %56 = getelementptr inbounds i64, ptr %51, i64 4
+  store i64 1, ptr %52, align 4
+  store i64 2, ptr %53, align 4
+  store i64 3, ptr %54, align 4
+  store i64 4, ptr %55, align 4
+  store i64 5, ptr %56, align 4
+  %57 = load [5 x i64], ptr %51, align 4
+  %58 = getelementptr inbounds i64, ptr %51, i64 2
+  %59 = load i64, ptr %58, align 4
+  %60 = call i32 (ptr, ...) @printf(ptr @3, i64 %59)
+  %61 = call %"github.com/goplus/llgo/internal/runtime.String" @"github.com/goplus/llgo/internal/runtime.NewString"(ptr @5, i64 6)
+  %62 = call ptr @"github.com/goplus/llgo/internal/runtime.StringData"(%"github.com/goplus/llgo/internal/runtime.String" %61)
+  %63 = getelementptr inbounds i8, ptr %62, i64 2
+  %64 = load i8, ptr %63, align 1
+  %65 = call i32 (ptr, ...) @printf(ptr @4, i8 %64)
+  %66 = call %"github.com/goplus/llgo/internal/runtime.String" @"github.com/goplus/llgo/internal/runtime.NewString"(ptr @7, i64 6)
+  %67 = call ptr @"github.com/goplus/llgo/internal/runtime.StringData"(%"github.com/goplus/llgo/internal/runtime.String" %66)
+  %68 = getelementptr inbounds i8, ptr %67, i64 1
+  %69 = load i8, ptr %68, align 1
+  %70 = call i32 (ptr, ...) @printf(ptr @6, i8 %69)
+  ret void
+}
+
+declare void @"github.com/goplus/llgo/internal/runtime.init"()
+
+declare ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr, i64)
+
+declare i32 @printf(ptr, ...)
+
+declare %"github.com/goplus/llgo/internal/runtime.String" @"github.com/goplus/llgo/internal/runtime.NewString"(ptr, i64)
+
+declare ptr @"github.com/goplus/llgo/internal/runtime.StringData"(%"github.com/goplus/llgo/internal/runtime.String")
diff --git a/cl/_testrt/qsort/out.ll b/cl/_testrt/qsort/out.ll
index c6699bd2..4e8a2f41 100644
--- a/cl/_testrt/qsort/out.ll
+++ b/cl/_testrt/qsort/out.ll
@@ -21,7 +21,7 @@ define void @main() {
 _llgo_0:
   call void @"github.com/goplus/llgo/internal/runtime.init"()
   call void @main.init()
-  %0 = call ptr @"github.com/goplus/llgo/internal/runtime.Alloc"(i64 40)
+  %0 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 40)
   %1 = getelementptr inbounds i64, ptr %0, i64 0
   %2 = getelementptr inbounds i64, ptr %0, i64 1
   %3 = getelementptr inbounds i64, ptr %0, i64 2
@@ -57,7 +57,7 @@ declare void @qsort(ptr, i64, i64, ptr)
 
 declare void @"github.com/goplus/llgo/internal/runtime.init"()
 
-declare ptr @"github.com/goplus/llgo/internal/runtime.Alloc"(i64)
+declare ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64)
 
 define i32 @"main.main$1"(ptr %0, ptr %1) {
 _llgo_0:
diff --git a/cl/_testrt/struct/out.ll b/cl/_testrt/struct/out.ll
index adead9a3..abce9854 100644
--- a/cl/_testrt/struct/out.ll
+++ b/cl/_testrt/struct/out.ll
@@ -9,15 +9,16 @@ source_filename = "main"
 define void @"(main.Foo).Print"(%main.Foo %0) {
 _llgo_0:
   %1 = alloca %main.Foo, align 8
-  store %main.Foo %0, ptr %1, align 4
-  %2 = getelementptr inbounds %main.Foo, ptr %1, i32 0, i32 1
-  %3 = load i1, ptr %2, align 1
-  br i1 %3, label %_llgo_1, label %_llgo_2
+  %2 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %1, i64 8)
+  store %main.Foo %0, ptr %2, align 4
+  %3 = getelementptr inbounds %main.Foo, ptr %2, i32 0, i32 1
+  %4 = load i1, ptr %3, align 1
+  br i1 %4, label %_llgo_1, label %_llgo_2
 
 _llgo_1:                                          ; preds = %_llgo_0
-  %4 = getelementptr inbounds %main.Foo, ptr %1, i32 0, i32 0
-  %5 = load i32, ptr %4, align 4
-  call void (ptr, ...) @printf(ptr @main.format, i32 %5)
+  %5 = getelementptr inbounds %main.Foo, ptr %2, i32 0, i32 0
+  %6 = load i32, ptr %5, align 4
+  call void (ptr, ...) @printf(ptr @main.format, i32 %6)
   br label %_llgo_2
 
 _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
@@ -59,15 +60,18 @@ _llgo_0:
   call void @"github.com/goplus/llgo/internal/runtime.init"()
   call void @main.init()
   %0 = alloca %main.Foo, align 8
-  %1 = getelementptr inbounds %main.Foo, ptr %0, i32 0, i32 0
-  %2 = getelementptr inbounds %main.Foo, ptr %0, i32 0, i32 1
-  store i32 100, ptr %1, align 4
-  store i1 true, ptr %2, align 1
-  %3 = load %main.Foo, ptr %0, align 4
-  call void @"(main.Foo).Print"(%main.Foo %3)
+  %1 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %0, i64 8)
+  %2 = getelementptr inbounds %main.Foo, ptr %1, i32 0, i32 0
+  %3 = getelementptr inbounds %main.Foo, ptr %1, i32 0, i32 1
+  store i32 100, ptr %2, align 4
+  store i1 true, ptr %3, align 1
+  %4 = load %main.Foo, ptr %1, align 4
+  call void @"(main.Foo).Print"(%main.Foo %4)
   ret void
 }
 
 declare void @printf(ptr, ...)
 
+declare ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr, i64)
+
 declare void @"github.com/goplus/llgo/internal/runtime.init"()
diff --git a/cl/_testrt/sum/out.ll b/cl/_testrt/sum/out.ll
index a41f91c5..24169d9d 100644
--- a/cl/_testrt/sum/out.ll
+++ b/cl/_testrt/sum/out.ll
@@ -23,7 +23,7 @@ define void @main() {
 _llgo_0:
   call void @"github.com/goplus/llgo/internal/runtime.init"()
   call void @main.init()
-  %0 = call ptr @"github.com/goplus/llgo/internal/runtime.Alloc"(i64 32)
+  %0 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 32)
   %1 = getelementptr inbounds i64, ptr %0, i64 0
   store i64 1, ptr %1, align 4
   %2 = getelementptr inbounds i64, ptr %0, i64 1
@@ -63,7 +63,7 @@ _llgo_3:                                          ; preds = %_llgo_1
 
 declare void @"github.com/goplus/llgo/internal/runtime.init"()
 
-declare ptr @"github.com/goplus/llgo/internal/runtime.Alloc"(i64)
+declare ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64)
 
 declare %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr, i64, i64, i64, i64, i64)
 
diff --git a/cl/_testrt/typalias/out.ll b/cl/_testrt/typalias/out.ll
index 655a98c3..3732bf97 100644
--- a/cl/_testrt/typalias/out.ll
+++ b/cl/_testrt/typalias/out.ll
@@ -47,7 +47,7 @@ define void @main() {
 _llgo_0:
   call void @"github.com/goplus/llgo/internal/runtime.init"()
   call void @main.init()
-  %0 = call ptr @"github.com/goplus/llgo/internal/runtime.Alloc"(i64 5)
+  %0 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 8)
   %1 = getelementptr inbounds { i32, i1 }, ptr %0, i32 0, i32 0
   %2 = getelementptr inbounds { i32, i1 }, ptr %0, i32 0, i32 1
   store i32 100, ptr %1, align 4
@@ -60,4 +60,4 @@ declare void @printf(ptr, ...)
 
 declare void @"github.com/goplus/llgo/internal/runtime.init"()
 
-declare ptr @"github.com/goplus/llgo/internal/runtime.Alloc"(i64)
+declare ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64)
diff --git a/cl/compile.go b/cl/compile.go
index 0e05e6f3..62d11ad3 100644
--- a/cl/compile.go
+++ b/cl/compile.go
@@ -504,13 +504,6 @@ func (p *context) compileInstrOrValue(b llssa.Builder, iv instrOrValue, asValue
 			max = p.compileValue(b, v.Max)
 		}
 		ret = b.Slice(x, low, high, max)
-	case *ssa.MakeMap:
-		var nReserve llssa.Expr
-		t := v.Type()
-		if v.Reserve != nil {
-			nReserve = p.compileValue(b, v.Reserve)
-		}
-		ret = b.MakeMap(p.prog.Type(t), nReserve)
 	case *ssa.MakeInterface:
 		const (
 			delayExpr = true // varargs: don't need to convert an expr to any
@@ -518,6 +511,21 @@ func (p *context) compileInstrOrValue(b llssa.Builder, iv instrOrValue, asValue
 		t := v.Type()
 		x := p.compileValue(b, v.X)
 		ret = b.MakeInterface(t, x, delayExpr)
+	case *ssa.MakeSlice:
+		var nCap llssa.Expr
+		t := v.Type()
+		nLen := p.compileValue(b, v.Len)
+		if v.Cap != nil {
+			nCap = p.compileValue(b, v.Cap)
+		}
+		ret = b.MakeSlice(p.prog.Type(t), nLen, nCap)
+	case *ssa.MakeMap:
+		var nReserve llssa.Expr
+		t := v.Type()
+		if v.Reserve != nil {
+			nReserve = p.compileValue(b, v.Reserve)
+		}
+		ret = b.MakeMap(p.prog.Type(t), nReserve)
 	case *ssa.TypeAssert:
 		x := p.compileValue(b, v.X)
 		ret = b.TypeAssert(x, p.prog.Type(v.AssertedType), v.CommaOk)
diff --git a/internal/runtime/llgo_autogen.ll b/internal/runtime/llgo_autogen.ll
index 392cc6e8..bec5ac78 100644
--- a/internal/runtime/llgo_autogen.ll
+++ b/internal/runtime/llgo_autogen.ll
@@ -19,12 +19,19 @@ source_filename = "github.com/goplus/llgo/internal/runtime"
 @__stderrp = external global ptr
 @3 = private unnamed_addr constant [11 x i8] c"panic: %s\0A\00", align 1
 
-define ptr @"github.com/goplus/llgo/internal/runtime.Alloc"(i64 %0) {
+define ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64 %0) {
 _llgo_0:
   %1 = call ptr @malloc(i64 %0)
   ret ptr %1
 }
 
+define ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 %0) {
+_llgo_0:
+  %1 = call ptr @malloc(i64 %0)
+  %2 = call ptr @memset(ptr %1, i32 0, i64 %0)
+  ret ptr %2
+}
+
 define ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 %0) {
 _llgo_0:
   %1 = getelementptr inbounds ptr, ptr @"github.com/goplus/llgo/internal/runtime.basicTypes", i64 %0
@@ -35,46 +42,49 @@ _llgo_0:
 define ptr @"github.com/goplus/llgo/internal/runtime.CStrCopy"(ptr %0, %"github.com/goplus/llgo/internal/runtime.String" %1) {
 _llgo_0:
   %2 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
-  store %"github.com/goplus/llgo/internal/runtime.String" %1, ptr %2, align 8
-  %3 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %2, i32 0, i32 1
-  %4 = load i64, ptr %3, align 4
-  %5 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %2, i32 0, i32 0
-  %6 = load ptr, ptr %5, align 8
-  %7 = call ptr @memcpy(ptr %0, ptr %6, i64 %4)
-  %8 = getelementptr inbounds i8, ptr %0, i64 %4
-  store i8 0, ptr %8, align 1
+  %3 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %2, i64 16)
+  store %"github.com/goplus/llgo/internal/runtime.String" %1, ptr %3, align 8
+  %4 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %3, i32 0, i32 1
+  %5 = load i64, ptr %4, align 4
+  %6 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %3, i32 0, i32 0
+  %7 = load ptr, ptr %6, align 8
+  %8 = call ptr @memcpy(ptr %0, ptr %7, i64 %5)
+  %9 = getelementptr inbounds i8, ptr %0, i64 %5
+  store i8 0, ptr %9, align 1
   ret ptr %0
 }
 
 define ptr @"github.com/goplus/llgo/internal/runtime.CStrDup"(%"github.com/goplus/llgo/internal/runtime.String" %0) {
 _llgo_0:
   %1 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
-  store %"github.com/goplus/llgo/internal/runtime.String" %0, ptr %1, align 8
-  %2 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %1, i32 0, i32 1
-  %3 = load i64, ptr %2, align 4
-  %4 = add i64 %3, 1
-  %5 = call ptr @"github.com/goplus/llgo/internal/runtime.Alloc"(i64 %4)
-  %6 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %1, align 8
-  %7 = call ptr @"github.com/goplus/llgo/internal/runtime.CStrCopy"(ptr %5, %"github.com/goplus/llgo/internal/runtime.String" %6)
-  ret ptr %7
+  %2 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %1, i64 16)
+  store %"github.com/goplus/llgo/internal/runtime.String" %0, ptr %2, align 8
+  %3 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %2, i32 0, i32 1
+  %4 = load i64, ptr %3, align 4
+  %5 = add i64 %4, 1
+  %6 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64 %5)
+  %7 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %2, align 8
+  %8 = call ptr @"github.com/goplus/llgo/internal/runtime.CStrCopy"(ptr %6, %"github.com/goplus/llgo/internal/runtime.String" %7)
+  ret ptr %8
 }
 
 define { i64, i1 } @"github.com/goplus/llgo/internal/runtime.CheckI2Int"(%"github.com/goplus/llgo/internal/runtime.iface" %0, ptr %1) {
 _llgo_0:
   %2 = alloca %"github.com/goplus/llgo/internal/runtime.iface", align 8
-  store %"github.com/goplus/llgo/internal/runtime.iface" %0, ptr %2, align 8
-  %3 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %2, i32 0, i32 0
-  %4 = load ptr, ptr %3, align 8
-  %5 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.itab", ptr %4, i32 0, i32 1
-  %6 = load ptr, ptr %5, align 8
-  %7 = icmp eq ptr %6, %1
-  br i1 %7, label %_llgo_1, label %_llgo_2
+  %3 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %2, i64 16)
+  store %"github.com/goplus/llgo/internal/runtime.iface" %0, ptr %3, align 8
+  %4 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %3, i32 0, i32 0
+  %5 = load ptr, ptr %4, align 8
+  %6 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.itab", ptr %5, i32 0, i32 1
+  %7 = load ptr, ptr %6, align 8
+  %8 = icmp eq ptr %7, %1
+  br i1 %8, label %_llgo_1, label %_llgo_2
 
 _llgo_1:                                          ; preds = %_llgo_0
-  %8 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %2, i32 0, i32 1
-  %9 = load ptr, ptr %8, align 8
-  %10 = ptrtoint ptr %9 to i64
-  %mrv = insertvalue { i64, i1 } poison, i64 %10, 0
+  %9 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %3, i32 0, i32 1
+  %10 = load ptr, ptr %9, align 8
+  %11 = ptrtoint ptr %10 to i64
+  %mrv = insertvalue { i64, i1 } poison, i64 %11, 0
   %mrv1 = insertvalue { i64, i1 } %mrv, i1 true, 1
   ret { i64, i1 } %mrv1
 
@@ -85,41 +95,43 @@ _llgo_2:                                          ; preds = %_llgo_0
 define %"github.com/goplus/llgo/internal/runtime.String" @"github.com/goplus/llgo/internal/runtime.EmptyString"() {
 _llgo_0:
   %0 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
-  %1 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %0, i32 0, i32 0
-  %2 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %0, i32 0, i32 1
-  store ptr null, ptr %1, align 8
-  store i64 0, ptr %2, align 4
-  %3 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %0, align 8
-  ret %"github.com/goplus/llgo/internal/runtime.String" %3
+  %1 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %0, i64 16)
+  %2 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %1, i32 0, i32 0
+  %3 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %1, i32 0, i32 1
+  store ptr null, ptr %2, align 8
+  store i64 0, ptr %3, align 4
+  %4 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %1, align 8
+  ret %"github.com/goplus/llgo/internal/runtime.String" %4
 }
 
 define i64 @"github.com/goplus/llgo/internal/runtime.I2Int"(%"github.com/goplus/llgo/internal/runtime.iface" %0, ptr %1) {
 _llgo_0:
   %2 = alloca %"github.com/goplus/llgo/internal/runtime.iface", align 8
-  store %"github.com/goplus/llgo/internal/runtime.iface" %0, ptr %2, align 8
-  %3 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %2, i32 0, i32 0
-  %4 = load ptr, ptr %3, align 8
-  %5 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.itab", ptr %4, i32 0, i32 1
-  %6 = load ptr, ptr %5, align 8
-  %7 = icmp eq ptr %6, %1
-  br i1 %7, label %_llgo_1, label %_llgo_2
+  %3 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %2, i64 16)
+  store %"github.com/goplus/llgo/internal/runtime.iface" %0, ptr %3, align 8
+  %4 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %3, i32 0, i32 0
+  %5 = load ptr, ptr %4, align 8
+  %6 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.itab", ptr %5, i32 0, i32 1
+  %7 = load ptr, ptr %6, align 8
+  %8 = icmp eq ptr %7, %1
+  br i1 %8, label %_llgo_1, label %_llgo_2
 
 _llgo_1:                                          ; preds = %_llgo_0
-  %8 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %2, i32 0, i32 1
-  %9 = load ptr, ptr %8, align 8
-  %10 = ptrtoint ptr %9 to i64
-  ret i64 %10
+  %9 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %3, i32 0, i32 1
+  %10 = load ptr, ptr %9, align 8
+  %11 = ptrtoint ptr %10 to i64
+  ret i64 %11
 
 _llgo_2:                                          ; preds = %_llgo_0
-  %11 = call %"github.com/goplus/llgo/internal/runtime.String" @"github.com/goplus/llgo/internal/runtime.NewString"(ptr @0, i64 20)
-  %12 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyString"(%"github.com/goplus/llgo/internal/runtime.String" %11)
-  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.iface" %12)
+  %12 = call %"github.com/goplus/llgo/internal/runtime.String" @"github.com/goplus/llgo/internal/runtime.NewString"(ptr @0, i64 20)
+  %13 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyString"(%"github.com/goplus/llgo/internal/runtime.String" %12)
+  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.iface" %13)
   unreachable
 }
 
 define %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAny"(ptr %0, ptr %1) {
 _llgo_0:
-  %2 = call ptr @"github.com/goplus/llgo/internal/runtime.Alloc"(i64 32)
+  %2 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 32)
   %3 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.itab", ptr %2, i32 0, i32 0
   %4 = load ptr, ptr @"github.com/goplus/llgo/internal/runtime.TyAny", align 8
   %5 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.itab", ptr %2, i32 0, i32 1
@@ -131,17 +143,18 @@ _llgo_0:
   store i32 0, ptr %6, align 4
   store i64 0, ptr %8, align 4
   %9 = alloca %"github.com/goplus/llgo/internal/runtime.iface", align 8
-  %10 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %9, i32 0, i32 0
-  %11 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %9, i32 0, i32 1
-  store ptr %2, ptr %10, align 8
-  store ptr %1, ptr %11, align 8
-  %12 = load %"github.com/goplus/llgo/internal/runtime.iface", ptr %9, align 8
-  ret %"github.com/goplus/llgo/internal/runtime.iface" %12
+  %10 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %9, i64 16)
+  %11 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %10, i32 0, i32 0
+  %12 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %10, i32 0, i32 1
+  store ptr %2, ptr %11, align 8
+  store ptr %1, ptr %12, align 8
+  %13 = load %"github.com/goplus/llgo/internal/runtime.iface", ptr %10, align 8
+  ret %"github.com/goplus/llgo/internal/runtime.iface" %13
 }
 
 define %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyInt"(ptr %0, i64 %1) {
 _llgo_0:
-  %2 = call ptr @"github.com/goplus/llgo/internal/runtime.Alloc"(i64 32)
+  %2 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 32)
   %3 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.itab", ptr %2, i32 0, i32 0
   %4 = load ptr, ptr @"github.com/goplus/llgo/internal/runtime.TyAny", align 8
   %5 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.itab", ptr %2, i32 0, i32 1
@@ -153,21 +166,22 @@ _llgo_0:
   store i32 0, ptr %6, align 4
   store i64 0, ptr %8, align 4
   %9 = alloca %"github.com/goplus/llgo/internal/runtime.iface", align 8
-  %10 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %9, i32 0, i32 0
-  %11 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %9, i32 0, i32 1
-  %12 = inttoptr i64 %1 to ptr
-  store ptr %2, ptr %10, align 8
-  store ptr %12, ptr %11, align 8
-  %13 = load %"github.com/goplus/llgo/internal/runtime.iface", ptr %9, align 8
-  ret %"github.com/goplus/llgo/internal/runtime.iface" %13
+  %10 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %9, i64 16)
+  %11 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %10, i32 0, i32 0
+  %12 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %10, i32 0, i32 1
+  %13 = inttoptr i64 %1 to ptr
+  store ptr %2, ptr %11, align 8
+  store ptr %13, ptr %12, align 8
+  %14 = load %"github.com/goplus/llgo/internal/runtime.iface", ptr %10, align 8
+  ret %"github.com/goplus/llgo/internal/runtime.iface" %14
 }
 
 define %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyString"(%"github.com/goplus/llgo/internal/runtime.String" %0) {
 _llgo_0:
-  %1 = call ptr @"github.com/goplus/llgo/internal/runtime.Alloc"(i64 16)
+  %1 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 16)
   store %"github.com/goplus/llgo/internal/runtime.String" %0, ptr %1, align 8
   %2 = load ptr, ptr getelementptr inbounds (ptr, ptr @"github.com/goplus/llgo/internal/runtime.basicTypes", i64 24), align 8
-  %3 = call ptr @"github.com/goplus/llgo/internal/runtime.Alloc"(i64 32)
+  %3 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 32)
   %4 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.itab", ptr %3, i32 0, i32 0
   %5 = load ptr, ptr @"github.com/goplus/llgo/internal/runtime.TyAny", align 8
   %6 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.itab", ptr %3, i32 0, i32 1
@@ -179,17 +193,18 @@ _llgo_0:
   store i32 0, ptr %7, align 4
   store i64 0, ptr %9, align 4
   %10 = alloca %"github.com/goplus/llgo/internal/runtime.iface", align 8
-  %11 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %10, i32 0, i32 0
-  %12 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %10, i32 0, i32 1
-  store ptr %3, ptr %11, align 8
-  store ptr %1, ptr %12, align 8
-  %13 = load %"github.com/goplus/llgo/internal/runtime.iface", ptr %10, align 8
-  ret %"github.com/goplus/llgo/internal/runtime.iface" %13
+  %11 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %10, i64 16)
+  %12 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %11, i32 0, i32 0
+  %13 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %11, i32 0, i32 1
+  store ptr %3, ptr %12, align 8
+  store ptr %1, ptr %13, align 8
+  %14 = load %"github.com/goplus/llgo/internal/runtime.iface", ptr %11, align 8
+  ret %"github.com/goplus/llgo/internal/runtime.iface" %14
 }
 
 define %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeInterface"(ptr %0, ptr %1, ptr %2) {
 _llgo_0:
-  %3 = call ptr @"github.com/goplus/llgo/internal/runtime.Alloc"(i64 32)
+  %3 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 32)
   %4 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.itab", ptr %3, i32 0, i32 0
   %5 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.itab", ptr %3, i32 0, i32 1
   %6 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.itab", ptr %3, i32 0, i32 2
@@ -200,12 +215,13 @@ _llgo_0:
   store i32 0, ptr %6, align 4
   store i64 0, ptr %8, align 4
   %9 = alloca %"github.com/goplus/llgo/internal/runtime.iface", align 8
-  %10 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %9, i32 0, i32 0
-  %11 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %9, i32 0, i32 1
-  store ptr %3, ptr %10, align 8
-  store ptr %2, ptr %11, align 8
-  %12 = load %"github.com/goplus/llgo/internal/runtime.iface", ptr %9, align 8
-  ret %"github.com/goplus/llgo/internal/runtime.iface" %12
+  %10 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %9, i64 16)
+  %11 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %10, i32 0, i32 0
+  %12 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %10, i32 0, i32 1
+  store ptr %3, ptr %11, align 8
+  store ptr %2, ptr %12, align 8
+  %13 = load %"github.com/goplus/llgo/internal/runtime.iface", ptr %10, align 8
+  ret %"github.com/goplus/llgo/internal/runtime.iface" %13
 }
 
 define ptr @"github.com/goplus/llgo/internal/runtime.MakeSmallMap"() {
@@ -217,263 +233,286 @@ _llgo_0:
 define %"github.com/goplus/llgo/internal/runtime.Closure" @"github.com/goplus/llgo/internal/runtime.NewClosure"(ptr %0, ptr %1) {
 _llgo_0:
   %2 = alloca %"github.com/goplus/llgo/internal/runtime.Closure", align 8
-  %3 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Closure", ptr %2, i32 0, i32 0
-  %4 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Closure", ptr %2, i32 0, i32 1
-  store ptr %0, ptr %3, align 8
-  store ptr %1, ptr %4, align 8
-  %5 = load %"github.com/goplus/llgo/internal/runtime.Closure", ptr %2, align 8
-  ret %"github.com/goplus/llgo/internal/runtime.Closure" %5
+  %3 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %2, i64 16)
+  %4 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Closure", ptr %3, i32 0, i32 0
+  %5 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Closure", ptr %3, i32 0, i32 1
+  store ptr %0, ptr %4, align 8
+  store ptr %1, ptr %5, align 8
+  %6 = load %"github.com/goplus/llgo/internal/runtime.Closure", ptr %3, align 8
+  ret %"github.com/goplus/llgo/internal/runtime.Closure" %6
 }
 
 define %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice"(ptr %0, i64 %1, i64 %2) {
 _llgo_0:
   %3 = alloca %"github.com/goplus/llgo/internal/runtime.Slice", align 8
-  %4 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %3, i32 0, i32 0
-  %5 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %3, i32 0, i32 1
-  %6 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %3, i32 0, i32 2
-  store ptr %0, ptr %4, align 8
-  store i64 %1, ptr %5, align 4
-  store i64 %2, ptr %6, align 4
-  %7 = load %"github.com/goplus/llgo/internal/runtime.Slice", ptr %3, align 8
-  ret %"github.com/goplus/llgo/internal/runtime.Slice" %7
+  %4 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %3, i64 24)
+  %5 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %4, i32 0, i32 0
+  %6 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %4, i32 0, i32 1
+  %7 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %4, i32 0, i32 2
+  store ptr %0, ptr %5, align 8
+  store i64 %1, ptr %6, align 4
+  store i64 %2, ptr %7, align 4
+  %8 = load %"github.com/goplus/llgo/internal/runtime.Slice", ptr %4, align 8
+  ret %"github.com/goplus/llgo/internal/runtime.Slice" %8
 }
 
 define %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NewSlice3"(ptr %0, i64 %1, i64 %2, i64 %3, i64 %4, i64 %5) {
 _llgo_0:
   %6 = alloca %"github.com/goplus/llgo/internal/runtime.Slice", align 8
-  %7 = icmp slt i64 %3, 0
-  br i1 %7, label %_llgo_1, label %_llgo_5
+  %7 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %6, i64 24)
+  %8 = icmp slt i64 %3, 0
+  br i1 %8, label %_llgo_1, label %_llgo_5
 
 _llgo_1:                                          ; preds = %_llgo_5, %_llgo_4, %_llgo_3, %_llgo_0
-  %8 = call %"github.com/goplus/llgo/internal/runtime.String" @"github.com/goplus/llgo/internal/runtime.NewString"(ptr @1, i64 25)
-  %9 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyString"(%"github.com/goplus/llgo/internal/runtime.String" %8)
-  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.iface" %9)
+  %9 = call %"github.com/goplus/llgo/internal/runtime.String" @"github.com/goplus/llgo/internal/runtime.NewString"(ptr @1, i64 25)
+  %10 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyString"(%"github.com/goplus/llgo/internal/runtime.String" %9)
+  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.iface" %10)
   unreachable
 
 _llgo_2:                                          ; preds = %_llgo_3
-  %10 = sub i64 %4, %3
-  %11 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %6, i32 0, i32 1
-  store i64 %10, ptr %11, align 4
-  %12 = sub i64 %5, %3
-  %13 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %6, i32 0, i32 2
-  store i64 %12, ptr %13, align 4
-  %14 = sub i64 %5, %3
-  %15 = icmp sgt i64 %14, 0
-  br i1 %15, label %_llgo_6, label %_llgo_8
+  %11 = sub i64 %4, %3
+  %12 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %7, i32 0, i32 1
+  store i64 %11, ptr %12, align 4
+  %13 = sub i64 %5, %3
+  %14 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %7, i32 0, i32 2
+  store i64 %13, ptr %14, align 4
+  %15 = sub i64 %5, %3
+  %16 = icmp sgt i64 %15, 0
+  br i1 %16, label %_llgo_6, label %_llgo_8
 
 _llgo_3:                                          ; preds = %_llgo_4
-  %16 = icmp sgt i64 %5, %2
-  br i1 %16, label %_llgo_1, label %_llgo_2
+  %17 = icmp sgt i64 %5, %2
+  br i1 %17, label %_llgo_1, label %_llgo_2
 
 _llgo_4:                                          ; preds = %_llgo_5
-  %17 = icmp slt i64 %5, %4
-  br i1 %17, label %_llgo_1, label %_llgo_3
+  %18 = icmp slt i64 %5, %4
+  br i1 %18, label %_llgo_1, label %_llgo_3
 
 _llgo_5:                                          ; preds = %_llgo_0
-  %18 = icmp slt i64 %4, %3
-  br i1 %18, label %_llgo_1, label %_llgo_4
+  %19 = icmp slt i64 %4, %3
+  br i1 %19, label %_llgo_1, label %_llgo_4
 
 _llgo_6:                                          ; preds = %_llgo_2
-  %19 = mul i64 %3, %1
-  %20 = getelementptr i8, ptr %0, i64 %19
-  %21 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %6, i32 0, i32 0
-  store ptr %20, ptr %21, align 8
+  %20 = mul i64 %3, %1
+  %21 = getelementptr i8, ptr %0, i64 %20
+  %22 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %7, i32 0, i32 0
+  store ptr %21, ptr %22, align 8
   br label %_llgo_7
 
 _llgo_7:                                          ; preds = %_llgo_8, %_llgo_6
-  %22 = load %"github.com/goplus/llgo/internal/runtime.Slice", ptr %6, align 8
-  ret %"github.com/goplus/llgo/internal/runtime.Slice" %22
+  %23 = load %"github.com/goplus/llgo/internal/runtime.Slice", ptr %7, align 8
+  ret %"github.com/goplus/llgo/internal/runtime.Slice" %23
 
 _llgo_8:                                          ; preds = %_llgo_2
-  %23 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %6, i32 0, i32 0
-  store ptr %0, ptr %23, align 8
+  %24 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %7, i32 0, i32 0
+  store ptr %0, ptr %24, align 8
   br label %_llgo_7
 }
 
 define %"github.com/goplus/llgo/internal/runtime.String" @"github.com/goplus/llgo/internal/runtime.NewString"(ptr %0, i64 %1) {
 _llgo_0:
   %2 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
-  %3 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %2, i32 0, i32 0
-  %4 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %2, i32 0, i32 1
-  store ptr %0, ptr %3, align 8
-  store i64 %1, ptr %4, align 4
-  %5 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %2, align 8
-  ret %"github.com/goplus/llgo/internal/runtime.String" %5
+  %3 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %2, i64 16)
+  %4 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %3, i32 0, i32 0
+  %5 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %3, i32 0, i32 1
+  store ptr %0, ptr %4, align 8
+  store i64 %1, ptr %5, align 4
+  %6 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %3, align 8
+  ret %"github.com/goplus/llgo/internal/runtime.String" %6
 }
 
 define %"github.com/goplus/llgo/internal/runtime.String" @"github.com/goplus/llgo/internal/runtime.NewStringSlice"(%"github.com/goplus/llgo/internal/runtime.String" %0, i64 %1, i64 %2) {
 _llgo_0:
   %3 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
-  store %"github.com/goplus/llgo/internal/runtime.String" %0, ptr %3, align 8
-  %4 = icmp slt i64 %1, 0
-  br i1 %4, label %_llgo_1, label %_llgo_4
+  %4 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %3, i64 16)
+  store %"github.com/goplus/llgo/internal/runtime.String" %0, ptr %4, align 8
+  %5 = icmp slt i64 %1, 0
+  br i1 %5, label %_llgo_1, label %_llgo_4
 
 _llgo_1:                                          ; preds = %_llgo_4, %_llgo_3, %_llgo_0
-  %5 = call %"github.com/goplus/llgo/internal/runtime.String" @"github.com/goplus/llgo/internal/runtime.NewString"(ptr @2, i64 32)
-  %6 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyString"(%"github.com/goplus/llgo/internal/runtime.String" %5)
-  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.iface" %6)
+  %6 = call %"github.com/goplus/llgo/internal/runtime.String" @"github.com/goplus/llgo/internal/runtime.NewString"(ptr @2, i64 32)
+  %7 = call %"github.com/goplus/llgo/internal/runtime.iface" @"github.com/goplus/llgo/internal/runtime.MakeAnyString"(%"github.com/goplus/llgo/internal/runtime.String" %6)
+  call void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.iface" %7)
   unreachable
 
 _llgo_2:                                          ; preds = %_llgo_3
-  %7 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %3, i32 0, i32 1
-  %8 = load i64, ptr %7, align 4
-  %9 = icmp slt i64 %1, %8
-  br i1 %9, label %_llgo_5, label %_llgo_6
+  %8 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %4, i32 0, i32 1
+  %9 = load i64, ptr %8, align 4
+  %10 = icmp slt i64 %1, %9
+  br i1 %10, label %_llgo_5, label %_llgo_6
 
 _llgo_3:                                          ; preds = %_llgo_4
-  %10 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %3, i32 0, i32 1
-  %11 = load i64, ptr %10, align 4
-  %12 = icmp sgt i64 %2, %11
-  br i1 %12, label %_llgo_1, label %_llgo_2
+  %11 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %4, i32 0, i32 1
+  %12 = load i64, ptr %11, align 4
+  %13 = icmp sgt i64 %2, %12
+  br i1 %13, label %_llgo_1, label %_llgo_2
 
 _llgo_4:                                          ; preds = %_llgo_0
-  %13 = icmp slt i64 %2, %1
-  br i1 %13, label %_llgo_1, label %_llgo_3
+  %14 = icmp slt i64 %2, %1
+  br i1 %14, label %_llgo_1, label %_llgo_3
 
 _llgo_5:                                          ; preds = %_llgo_2
-  %14 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
-  %15 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %14, i32 0, i32 0
-  %16 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %3, i32 0, i32 0
-  %17 = load ptr, ptr %16, align 8
-  %18 = getelementptr i8, ptr %17, i64 %1
-  %19 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %14, i32 0, i32 1
-  %20 = sub i64 %2, %1
-  store ptr %18, ptr %15, align 8
-  store i64 %20, ptr %19, align 4
-  %21 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %14, align 8
-  ret %"github.com/goplus/llgo/internal/runtime.String" %21
+  %15 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
+  %16 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %15, i64 16)
+  %17 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %16, i32 0, i32 0
+  %18 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %4, i32 0, i32 0
+  %19 = load ptr, ptr %18, align 8
+  %20 = getelementptr i8, ptr %19, i64 %1
+  %21 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %16, i32 0, i32 1
+  %22 = sub i64 %2, %1
+  store ptr %20, ptr %17, align 8
+  store i64 %22, ptr %21, align 4
+  %23 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %16, align 8
+  ret %"github.com/goplus/llgo/internal/runtime.String" %23
 
 _llgo_6:                                          ; preds = %_llgo_2
-  %22 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
-  %23 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %22, i32 0, i32 0
-  %24 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %22, i32 0, i32 1
-  store ptr null, ptr %23, align 8
-  store i64 0, ptr %24, align 4
-  %25 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %22, align 8
-  ret %"github.com/goplus/llgo/internal/runtime.String" %25
+  %24 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
+  %25 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %24, i64 16)
+  %26 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %25, i32 0, i32 0
+  %27 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %25, i32 0, i32 1
+  store ptr null, ptr %26, align 8
+  store i64 0, ptr %27, align 4
+  %28 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %25, align 8
+  ret %"github.com/goplus/llgo/internal/runtime.String" %28
 }
 
 define %"github.com/goplus/llgo/internal/runtime.Slice" @"github.com/goplus/llgo/internal/runtime.NilSlice"() {
 _llgo_0:
   %0 = alloca %"github.com/goplus/llgo/internal/runtime.Slice", align 8
-  %1 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %0, i32 0, i32 0
-  %2 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %0, i32 0, i32 1
-  %3 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %0, i32 0, i32 2
-  store ptr null, ptr %1, align 8
-  store i64 0, ptr %2, align 4
+  %1 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %0, i64 24)
+  %2 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %1, i32 0, i32 0
+  %3 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %1, i32 0, i32 1
+  %4 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %1, i32 0, i32 2
+  store ptr null, ptr %2, align 8
   store i64 0, ptr %3, align 4
-  %4 = load %"github.com/goplus/llgo/internal/runtime.Slice", ptr %0, align 8
-  ret %"github.com/goplus/llgo/internal/runtime.Slice" %4
+  store i64 0, ptr %4, align 4
+  %5 = load %"github.com/goplus/llgo/internal/runtime.Slice", ptr %1, align 8
+  ret %"github.com/goplus/llgo/internal/runtime.Slice" %5
 }
 
 define i64 @"github.com/goplus/llgo/internal/runtime.SliceCap"(%"github.com/goplus/llgo/internal/runtime.Slice" %0) {
 _llgo_0:
   %1 = alloca %"github.com/goplus/llgo/internal/runtime.Slice", align 8
-  store %"github.com/goplus/llgo/internal/runtime.Slice" %0, ptr %1, align 8
-  %2 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %1, i32 0, i32 2
-  %3 = load i64, ptr %2, align 4
-  ret i64 %3
+  %2 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %1, i64 24)
+  store %"github.com/goplus/llgo/internal/runtime.Slice" %0, ptr %2, align 8
+  %3 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %2, i32 0, i32 2
+  %4 = load i64, ptr %3, align 4
+  ret i64 %4
 }
 
 define ptr @"github.com/goplus/llgo/internal/runtime.SliceData"(%"github.com/goplus/llgo/internal/runtime.Slice" %0) {
 _llgo_0:
   %1 = alloca %"github.com/goplus/llgo/internal/runtime.Slice", align 8
-  store %"github.com/goplus/llgo/internal/runtime.Slice" %0, ptr %1, align 8
-  %2 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %1, i32 0, i32 0
-  %3 = load ptr, ptr %2, align 8
-  ret ptr %3
+  %2 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %1, i64 24)
+  store %"github.com/goplus/llgo/internal/runtime.Slice" %0, ptr %2, align 8
+  %3 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %2, i32 0, i32 0
+  %4 = load ptr, ptr %3, align 8
+  ret ptr %4
 }
 
 define i64 @"github.com/goplus/llgo/internal/runtime.SliceLen"(%"github.com/goplus/llgo/internal/runtime.Slice" %0) {
 _llgo_0:
   %1 = alloca %"github.com/goplus/llgo/internal/runtime.Slice", align 8
-  store %"github.com/goplus/llgo/internal/runtime.Slice" %0, ptr %1, align 8
-  %2 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %1, i32 0, i32 1
-  %3 = load i64, ptr %2, align 4
-  ret i64 %3
+  %2 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %1, i64 24)
+  store %"github.com/goplus/llgo/internal/runtime.Slice" %0, ptr %2, align 8
+  %3 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %2, i32 0, i32 1
+  %4 = load i64, ptr %3, align 4
+  ret i64 %4
 }
 
 define %"github.com/goplus/llgo/internal/runtime.String" @"github.com/goplus/llgo/internal/runtime.StringCat"(%"github.com/goplus/llgo/internal/runtime.String" %0, %"github.com/goplus/llgo/internal/runtime.String" %1) {
 _llgo_0:
   %2 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
-  store %"github.com/goplus/llgo/internal/runtime.String" %0, ptr %2, align 8
-  %3 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
-  store %"github.com/goplus/llgo/internal/runtime.String" %1, ptr %3, align 8
-  %4 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %2, i32 0, i32 1
-  %5 = load i64, ptr %4, align 4
+  %3 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %2, i64 16)
+  store %"github.com/goplus/llgo/internal/runtime.String" %0, ptr %3, align 8
+  %4 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
+  %5 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %4, i64 16)
+  store %"github.com/goplus/llgo/internal/runtime.String" %1, ptr %5, align 8
   %6 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %3, i32 0, i32 1
   %7 = load i64, ptr %6, align 4
-  %8 = add i64 %5, %7
-  %9 = call ptr @"github.com/goplus/llgo/internal/runtime.Alloc"(i64 %8)
-  %10 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %2, i32 0, i32 0
-  %11 = load ptr, ptr %10, align 8
-  %12 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %2, i32 0, i32 1
-  %13 = load i64, ptr %12, align 4
-  %14 = call ptr @memcpy(ptr %9, ptr %11, i64 %13)
-  %15 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %2, i32 0, i32 1
-  %16 = load i64, ptr %15, align 4
-  %17 = getelementptr i8, ptr %9, i64 %16
-  %18 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %3, i32 0, i32 0
-  %19 = load ptr, ptr %18, align 8
-  %20 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %3, i32 0, i32 1
-  %21 = load i64, ptr %20, align 4
-  %22 = call ptr @memcpy(ptr %17, ptr %19, i64 %21)
-  %23 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
-  %24 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %23, i32 0, i32 0
-  %25 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %23, i32 0, i32 1
-  store ptr %9, ptr %24, align 8
-  store i64 %8, ptr %25, align 4
-  %26 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %23, align 8
-  ret %"github.com/goplus/llgo/internal/runtime.String" %26
+  %8 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %5, i32 0, i32 1
+  %9 = load i64, ptr %8, align 4
+  %10 = add i64 %7, %9
+  %11 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64 %10)
+  %12 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %3, i32 0, i32 0
+  %13 = load ptr, ptr %12, align 8
+  %14 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %3, i32 0, i32 1
+  %15 = load i64, ptr %14, align 4
+  %16 = call ptr @memcpy(ptr %11, ptr %13, i64 %15)
+  %17 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %3, i32 0, i32 1
+  %18 = load i64, ptr %17, align 4
+  %19 = getelementptr i8, ptr %11, i64 %18
+  %20 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %5, i32 0, i32 0
+  %21 = load ptr, ptr %20, align 8
+  %22 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %5, i32 0, i32 1
+  %23 = load i64, ptr %22, align 4
+  %24 = call ptr @memcpy(ptr %19, ptr %21, i64 %23)
+  %25 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
+  %26 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %25, i64 16)
+  %27 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %26, i32 0, i32 0
+  %28 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %26, i32 0, i32 1
+  store ptr %11, ptr %27, align 8
+  store i64 %10, ptr %28, align 4
+  %29 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %26, align 8
+  ret %"github.com/goplus/llgo/internal/runtime.String" %29
 }
 
 define ptr @"github.com/goplus/llgo/internal/runtime.StringData"(%"github.com/goplus/llgo/internal/runtime.String" %0) {
 _llgo_0:
   %1 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
-  store %"github.com/goplus/llgo/internal/runtime.String" %0, ptr %1, align 8
-  %2 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %1, i32 0, i32 0
-  %3 = load ptr, ptr %2, align 8
-  ret ptr %3
+  %2 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %1, i64 16)
+  store %"github.com/goplus/llgo/internal/runtime.String" %0, ptr %2, align 8
+  %3 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %2, i32 0, i32 0
+  %4 = load ptr, ptr %3, align 8
+  ret ptr %4
 }
 
 define i64 @"github.com/goplus/llgo/internal/runtime.StringLen"(%"github.com/goplus/llgo/internal/runtime.String" %0) {
 _llgo_0:
   %1 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
-  store %"github.com/goplus/llgo/internal/runtime.String" %0, ptr %1, align 8
-  %2 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %1, i32 0, i32 1
-  %3 = load i64, ptr %2, align 4
-  ret i64 %3
+  %2 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %1, i64 16)
+  store %"github.com/goplus/llgo/internal/runtime.String" %0, ptr %2, align 8
+  %3 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %2, i32 0, i32 1
+  %4 = load i64, ptr %3, align 4
+  ret i64 %4
 }
 
 define void @"github.com/goplus/llgo/internal/runtime.TracePanic"(%"github.com/goplus/llgo/internal/runtime.iface" %0) {
 _llgo_0:
   %1 = alloca %"github.com/goplus/llgo/internal/runtime.iface", align 8
-  store %"github.com/goplus/llgo/internal/runtime.iface" %0, ptr %1, align 8
-  %2 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %1, i32 0, i32 0
-  %3 = load ptr, ptr %2, align 8
-  %4 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.itab", ptr %3, i32 0, i32 1
-  %5 = load ptr, ptr %4, align 8
-  %6 = getelementptr inbounds %"github.com/goplus/llgo/internal/abi.Type", ptr %5, i32 0, i32 6
-  %7 = load i8, ptr %6, align 1
-  %8 = sext i8 %7 to i64
-  %9 = icmp eq i64 %8, 24
-  br i1 %9, label %_llgo_2, label %_llgo_1
+  %2 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %1, i64 16)
+  store %"github.com/goplus/llgo/internal/runtime.iface" %0, ptr %2, align 8
+  %3 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %2, i32 0, i32 0
+  %4 = load ptr, ptr %3, align 8
+  %5 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.itab", ptr %4, i32 0, i32 1
+  %6 = load ptr, ptr %5, align 8
+  %7 = getelementptr inbounds %"github.com/goplus/llgo/internal/abi.Type", ptr %6, i32 0, i32 6
+  %8 = load i8, ptr %7, align 1
+  %9 = sext i8 %8 to i64
+  %10 = icmp eq i64 %9, 24
+  br i1 %10, label %_llgo_2, label %_llgo_1
 
 _llgo_1:                                          ; preds = %_llgo_2, %_llgo_0
   ret void
 
 _llgo_2:                                          ; preds = %_llgo_0
-  %10 = load ptr, ptr @__stderrp, align 8
-  %11 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %1, i32 0, i32 1
-  %12 = load ptr, ptr %11, align 8
-  %13 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %12, align 8
-  call void @"github.com/goplus/llgo/internal/runtime.stringTracef"(ptr %10, ptr @3, %"github.com/goplus/llgo/internal/runtime.String" %13)
+  %11 = load ptr, ptr @__stderrp, align 8
+  %12 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.iface", ptr %2, i32 0, i32 1
+  %13 = load ptr, ptr %12, align 8
+  %14 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %13, align 8
+  call void @"github.com/goplus/llgo/internal/runtime.stringTracef"(ptr %11, ptr @3, %"github.com/goplus/llgo/internal/runtime.String" %14)
   br label %_llgo_1
 }
 
+define ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %0, i64 %1) {
+_llgo_0:
+  %2 = call ptr @memset(ptr %0, i32 0, i64 %1)
+  ret ptr %2
+}
+
 define ptr @"github.com/goplus/llgo/internal/runtime.basicType"(i64 %0) {
 _llgo_0:
-  %1 = call ptr @"github.com/goplus/llgo/internal/runtime.Alloc"(i64 48)
+  %1 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 56)
   %2 = getelementptr inbounds %"github.com/goplus/llgo/internal/abi.Type", ptr %1, i32 0, i32 0
   %3 = getelementptr inbounds i64, ptr @"github.com/goplus/llgo/internal/runtime.sizeBasicTypes", i64 %0
   %4 = load i64, ptr %3, align 4
@@ -497,7 +536,7 @@ _llgo_0:
 _llgo_1:                                          ; preds = %_llgo_0
   store i1 true, ptr @"github.com/goplus/llgo/internal/runtime.init$guard", align 1
   call void @"github.com/goplus/llgo/internal/abi.init"()
-  %1 = call ptr @"github.com/goplus/llgo/internal/runtime.Alloc"(i64 80)
+  %1 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 88)
   store ptr %1, ptr @"github.com/goplus/llgo/internal/runtime.TyAny", align 8
   store i64 1, ptr getelementptr inbounds (i64, ptr @"github.com/goplus/llgo/internal/runtime.sizeBasicTypes", i64 1), align 4
   store i64 8, ptr getelementptr inbounds (i64, ptr @"github.com/goplus/llgo/internal/runtime.sizeBasicTypes", i64 2), align 4
@@ -564,7 +603,7 @@ _llgo_0:
 
 define ptr @"github.com/goplus/llgo/internal/runtime.makemap_small"() {
 _llgo_0:
-  %0 = call ptr @"github.com/goplus/llgo/internal/runtime.Alloc"(i64 48)
+  %0 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 48)
   %1 = call i32 @rand()
   %2 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.hmap", ptr %0, i32 0, i32 4
   store i32 %1, ptr %2, align 4
@@ -574,19 +613,22 @@ _llgo_0:
 define void @"github.com/goplus/llgo/internal/runtime.stringTracef"(ptr %0, ptr %1, %"github.com/goplus/llgo/internal/runtime.String" %2) {
 _llgo_0:
   %3 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
-  store %"github.com/goplus/llgo/internal/runtime.String" %2, ptr %3, align 8
-  %4 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %3, i32 0, i32 1
-  %5 = load i64, ptr %4, align 4
-  %6 = add i64 %5, 1
-  %7 = alloca i8, i64 %6, align 1
-  %8 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %3, align 8
-  %9 = call ptr @"github.com/goplus/llgo/internal/runtime.CStrCopy"(ptr %7, %"github.com/goplus/llgo/internal/runtime.String" %8)
-  %10 = call i32 (ptr, ptr, ...) @fprintf(ptr %0, ptr %1, ptr %9)
+  %4 = call ptr @"github.com/goplus/llgo/internal/runtime.Zeroinit"(ptr %3, i64 16)
+  store %"github.com/goplus/llgo/internal/runtime.String" %2, ptr %4, align 8
+  %5 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %4, i32 0, i32 1
+  %6 = load i64, ptr %5, align 4
+  %7 = add i64 %6, 1
+  %8 = alloca i8, i64 %7, align 1
+  %9 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %4, align 8
+  %10 = call ptr @"github.com/goplus/llgo/internal/runtime.CStrCopy"(ptr %8, %"github.com/goplus/llgo/internal/runtime.String" %9)
+  %11 = call i32 (ptr, ptr, ...) @fprintf(ptr %0, ptr %1, ptr %10)
   ret void
 }
 
 declare ptr @malloc(i64)
 
+declare ptr @memset(ptr, i32, i64)
+
 declare ptr @memcpy(ptr, ptr, i64)
 
 declare void @"github.com/goplus/llgo/internal/abi.init"()
diff --git a/internal/runtime/z_c.go b/internal/runtime/z_c.go
index 53a00a31..1ea1efbd 100644
--- a/internal/runtime/z_c.go
+++ b/internal/runtime/z_c.go
@@ -23,11 +23,22 @@ import (
 	"github.com/goplus/llgo/internal/runtime/c"
 )
 
-// Alloc allocates memory.
-func Alloc(size uintptr) unsafe.Pointer {
+// AllocU allocates uninitialized memory.
+func AllocU(size uintptr) unsafe.Pointer {
 	return c.Malloc(size)
 }
 
+// AllocZ allocates zero-initialized memory.
+func AllocZ(size uintptr) unsafe.Pointer {
+	ret := c.Malloc(size)
+	return c.Memset(ret, 0, size)
+}
+
+// Zeroinit initializes memory to zero.
+func Zeroinit(p c.Pointer, size uintptr) c.Pointer {
+	return c.Memset(p, 0, size)
+}
+
 // TracePanic prints panic message.
 func TracePanic(v Interface) {
 	kind := abi.Kind(v.tab._type.Kind_)
diff --git a/internal/runtime/z_slice.go b/internal/runtime/z_slice.go
index 15fb1a8d..f20924fb 100644
--- a/internal/runtime/z_slice.go
+++ b/internal/runtime/z_slice.go
@@ -41,6 +41,20 @@ func NewSlice(data unsafe.Pointer, len, cap int) Slice {
 	return Slice{data, len, cap}
 }
 
+func NewSlice3(base unsafe.Pointer, eltSize, cap, i, j, k int) (s Slice) {
+	if i < 0 || j < i || k < j || k > cap {
+		panic("slice index out of bounds")
+	}
+	s.len = j - i
+	s.cap = k - i
+	if k-i > 0 {
+		s.data = c.Advance(base, i*eltSize)
+	} else {
+		s.data = base
+	}
+	return
+}
+
 // SliceLen returns the length of a slice.
 func SliceLen(s Slice) int {
 	return s.len
@@ -56,18 +70,4 @@ func SliceData(s Slice) unsafe.Pointer {
 	return s.data
 }
 
-func NewSlice3(base unsafe.Pointer, eltSize, cap, i, j, k int) (s Slice) {
-	if i < 0 || j < i || k < j || k > cap {
-		panic("slice index out of bounds")
-	}
-	s.len = j - i
-	s.cap = k - i
-	if k-i > 0 {
-		s.data = c.Advance(base, i*eltSize)
-	} else {
-		s.data = base
-	}
-	return
-}
-
 // -----------------------------------------------------------------------------
diff --git a/internal/runtime/z_string.go b/internal/runtime/z_string.go
index 69079149..ee52e2c0 100644
--- a/internal/runtime/z_string.go
+++ b/internal/runtime/z_string.go
@@ -58,7 +58,7 @@ func StringData(s String) unsafe.Pointer {
 // StringCat concatenates two strings.
 func StringCat(a, b String) String {
 	n := a.len + b.len
-	dest := Alloc(uintptr(n))
+	dest := AllocU(uintptr(n))
 	c.Memcpy(dest, a.data, uintptr(a.len))
 	c.Memcpy(c.Advance(dest, a.len), b.data, uintptr(b.len))
 	return String{dest, n}
@@ -76,7 +76,7 @@ func CStrCopy(dest unsafe.Pointer, s String) *int8 {
 }
 
 func CStrDup(s String) *int8 {
-	dest := Alloc(uintptr(s.len + 1))
+	dest := AllocU(uintptr(s.len + 1))
 	return CStrCopy(dest, s)
 }
 
diff --git a/ssa/expr.go b/ssa/expr.go
index 55003ae7..19c4d5ff 100644
--- a/ssa/expr.go
+++ b/ssa/expr.go
@@ -173,6 +173,13 @@ func (b Builder) Const(v constant.Value, typ Type) Expr {
 	panic(fmt.Sprintf("unsupported Const: %v, %v", v, typ.t))
 }
 
+// SizeOf returns the size of a type.
+func (b Builder) SizeOf(t Type, n ...int64) Expr {
+	prog := b.Prog
+	size := prog.SizeOf(t, n...)
+	return prog.IntVal(size, prog.Uintptr())
+}
+
 // CStr returns a c-style string constant expression.
 func (b Builder) CStr(v string) Expr {
 	return Expr{llvm.CreateGlobalStringPtr(b.impl, v), b.Prog.CStr()}
@@ -483,12 +490,6 @@ func (b Builder) aggregateValue(t Type, flds ...llvm.Value) Expr {
 //
 // Type() returns a (possibly named) *types.Pointer.
 //
-// Pos() returns the position of the ast.SelectorExpr.Sel for the
-// field, if explicit in the source. For implicit selections, returns
-// the position of the inducing explicit selection. If produced for a
-// struct literal S{f: e}, it returns the position of the colon; for
-// S{e} it returns the start of expression e.
-//
 // Example printed form:
 //
 //	t1 = &t0.name [#1]
@@ -561,7 +562,8 @@ func (b Builder) Index(x, idx Expr, addr func(Expr) Expr) Expr {
 		if addr != nil {
 			ptr = addr(x)
 		} else {
-			ptr = b.Alloca(prog.IntVal(uint64(t.Len()*b.Prog.sizs.Sizeof(t.Elem())), prog.Index(x.Type)))
+			size := b.SizeOf(telem, t.Len())
+			ptr = b.Alloca(size)
 			b.Store(ptr, x)
 		}
 	}
@@ -580,10 +582,6 @@ func (b Builder) Index(x, idx Expr, addr func(Expr) Expr) Expr {
 // Type() returns string if the type of X was string, otherwise a
 // *types.Slice with the same element type as X.
 //
-// Pos() returns the ast.SliceExpr.Lbrack if created by a x[:] slice
-// operation, the ast.CompositeLit.Lbrace if created by a literal, or
-// NoPos if not explicit in the source (e.g. a variadic argument slice).
-//
 // Example printed form:
 //
 //	t1 = slice t0[1:]
@@ -601,12 +599,9 @@ func (b Builder) Slice(x, low, high, max Expr) (ret Expr) {
 	}
 	switch t := x.t.Underlying().(type) {
 	case *types.Basic:
-		if t.Info()&types.IsString == 0 {
+		if t.Kind() != types.String {
 			panic(fmt.Errorf("invalid operation: cannot slice %v", t))
 		}
-		if !max.IsNil() {
-			panic("invalid operation: 3-index slice of string")
-		}
 		if high.IsNil() {
 			high = b.InlineCall(pkg.rtFunc("StringLen"), x)
 		}
@@ -614,8 +609,8 @@ func (b Builder) Slice(x, low, high, max Expr) (ret Expr) {
 		ret.impl = b.InlineCall(pkg.rtFunc("NewStringSlice"), x, low, high).impl
 		return
 	case *types.Slice:
+		nEltSize = b.SizeOf(prog.Index(x.Type))
 		nCap = b.InlineCall(pkg.rtFunc("SliceCap"), x)
-		nEltSize = prog.IntVal(uint64(prog.sizs.Sizeof(t.Elem())), prog.Int())
 		if high.IsNil() {
 			high = b.InlineCall(pkg.rtFunc("SliceLen"), x)
 		}
@@ -625,9 +620,10 @@ func (b Builder) Slice(x, low, high, max Expr) (ret Expr) {
 		telem := t.Elem()
 		switch te := telem.Underlying().(type) {
 		case *types.Array:
-			ret.Type = prog.Type(types.NewSlice(te.Elem()))
+			elem := prog.Type(te.Elem())
+			ret.Type = prog.Slice(elem)
+			nEltSize = b.SizeOf(elem)
 			nCap = prog.IntVal(uint64(te.Len()), prog.Int())
-			nEltSize = prog.IntVal(uint64(prog.sizs.Sizeof(te.Elem())), prog.Int())
 			if high.IsNil() {
 				high = nCap
 			}
@@ -648,9 +644,6 @@ func (b Builder) Slice(x, low, high, max Expr) (ret Expr) {
 //
 // t is a (possibly named) *types.Map.
 //
-// Pos() returns the ast.CallExpr.Lparen, if created by make(map), or
-// the ast.CompositeLit.Lbrack if created by a literal.
-//
 // Example printed form:
 //
 //	t1 = make map[string]int t0
@@ -666,6 +659,36 @@ func (b Builder) MakeMap(t Type, nReserve Expr) (ret Expr) {
 	return
 }
 
+// The MakeSlice instruction yields a slice of length Len backed by a
+// newly allocated array of length Cap.
+//
+// Both Len and Cap must be non-nil Values of integer type.
+//
+// (Alloc(types.Array) followed by Slice will not suffice because
+// Alloc can only create arrays of constant length.)
+//
+// Type() returns a (possibly named) *types.Slice.
+//
+// Example printed form:
+//
+//	t1 = make []string 1:int t0
+//	t1 = make StringSlice 1:int t0
+func (b Builder) MakeSlice(t Type, len, cap Expr) (ret Expr) {
+	if debugInstr {
+		log.Printf("MakeSlice %v, %v, %v\n", t, len.impl, cap.impl)
+	}
+	pkg := b.fn.pkg
+	if cap.IsNil() {
+		cap = len
+	}
+	elemSize := b.SizeOf(b.Prog.Elem(t))
+	size := b.BinOp(token.MUL, cap, elemSize)
+	ptr := b.InlineCall(pkg.rtFunc("AllocZ"), size)
+	ret.impl = b.InlineCall(pkg.rtFunc("NewSlice"), ptr, len, cap).impl
+	ret.Type = t
+	return
+}
+
 // -----------------------------------------------------------------------------
 
 // The Alloc instruction reserves space for a variable of the given type,
@@ -692,15 +715,15 @@ func (b Builder) Alloc(t *types.Pointer, heap bool) (ret Expr) {
 		log.Printf("Alloc %v, %v\n", t, heap)
 	}
 	prog := b.Prog
-	telem := t.Elem()
+	pkg := b.fn.pkg
+	elem := prog.Type(t.Elem())
+	size := b.SizeOf(elem)
 	if heap {
-		pkg := b.fn.pkg
-		size := prog.sizs.Sizeof(telem)
-		ret = b.Call(pkg.rtFunc("Alloc"), prog.Val(uintptr(size)))
+		ret = b.InlineCall(pkg.rtFunc("AllocZ"), size)
 	} else {
-		ret.impl = llvm.CreateAlloca(b.impl, prog.Type(telem).ll)
+		ret = Expr{llvm.CreateAlloca(b.impl, elem.ll), prog.VoidPtr()}
+		ret.impl = b.InlineCall(pkg.rtFunc("Zeroinit"), ret, size).impl
 	}
-	// TODO(xsw): zero-initialize
 	ret.Type = prog.Type(t)
 	return
 }
@@ -802,9 +825,6 @@ func (b Builder) ChangeType(t Type, x Expr) (ret Expr) {
 // Conversions of untyped string/number/bool constants to a specific
 // representation are eliminated during SSA construction.
 //
-// Pos() returns the ast.CallExpr.Lparen, if the instruction arose
-// from an explicit conversion in the source.
-//
 // Example printed form:
 //
 //	t1 = convert []byte <- string (t0)
@@ -857,9 +877,6 @@ func castPtr(b llvm.Builder, x llvm.Value, t llvm.Type) llvm.Value {
 //
 //	NewConst(constant.MakeNil(), T, pos)
 //
-// Pos() returns the ast.CallExpr.Lparen, if the instruction arose
-// from an explicit conversion in the source.
-//
 // Example printed form:
 //
 //	t1 = make interface{} <- int (42:int)
diff --git a/ssa/package.go b/ssa/package.go
index 0d3800cb..ac464669 100644
--- a/ssa/package.go
+++ b/ssa/package.go
@@ -18,7 +18,6 @@ package ssa
 
 import (
 	"go/types"
-	"runtime"
 
 	"github.com/goplus/llgo/internal/typeutil"
 	"github.com/goplus/llvm"
@@ -97,7 +96,7 @@ func Initialize(flags InitFlags) {
 type aProgram struct {
 	ctx  llvm.Context
 	typs typeutil.Map
-	sizs types.Sizes
+	// sizs types.Sizes
 
 	rt    *types.Package
 	rtget func() *types.Package
@@ -123,6 +122,7 @@ type aProgram struct {
 
 	anyTy     Type
 	voidTy    Type
+	voidPtr   Type
 	boolTy    Type
 	cstrTy    Type
 	stringTy  Type
@@ -141,16 +141,19 @@ func NewProgram(target *Target) Program {
 	if target == nil {
 		target = &Target{}
 	}
-	arch := target.GOARCH
-	if arch == "" {
-		arch = runtime.GOARCH
-	}
 	ctx := llvm.NewContext()
-	sizes := types.SizesFor("gc", arch)
-	// TODO(xsw): Finalize may cause panic, so comment it.
-	// ctx.Finalize()
 	td := llvm.NewTargetData("") // TODO(xsw): target config
-	return &aProgram{ctx: ctx, sizs: sizes, target: target, td: td}
+	/*
+		arch := target.GOARCH
+		if arch == "" {
+			arch = runtime.GOARCH
+		}
+		sizes := types.SizesFor("gc", arch)
+
+		// TODO(xsw): Finalize may cause panic, so comment it.
+		ctx.Finalize()
+	*/
+	return &aProgram{ctx: ctx, target: target, td: td}
 }
 
 // SetRuntime sets the runtime.
@@ -239,6 +242,13 @@ func (p Program) Void() Type {
 	return p.voidTy
 }
 
+func (p Program) VoidPtr() Type {
+	if p.voidPtr == nil {
+		p.voidPtr = p.Type(types.Typ[types.UnsafePointer])
+	}
+	return p.voidPtr
+}
+
 // Bool returns bool type.
 func (p Program) Bool() Type {
 	if p.boolTy == nil {
diff --git a/ssa/type.go b/ssa/type.go
index b983a22e..5f83bbf0 100644
--- a/ssa/type.go
+++ b/ssa/type.go
@@ -91,11 +91,19 @@ type aType struct {
 
 type Type = *aType
 
-/*
+// TODO(xsw):
+// how to generate platform independent code?
+func (p Program) SizeOf(typ Type, n ...int64) uint64 {
+	size := p.td.TypeStoreSize(typ.ll)
+	if len(n) != 0 {
+		size *= uint64(n[0])
+	}
+	return size
+}
+
 func (p Program) Slice(typ Type) Type {
 	return p.Type(types.NewSlice(typ.t))
 }
-*/
 
 func (p Program) Pointer(typ Type) Type {
 	return p.Type(types.NewPointer(typ.t))