diff --git a/morphisms/.gitignore b/morphisms/.gitignore
new file mode 100644
index 0000000..82f5cc4
--- /dev/null
+++ b/morphisms/.gitignore
@@ -0,0 +1,6 @@
+*.so
+posint-dec-to-hex-generated-gcc
+posint-dec-to-hex-generated-clang
+posint-dec-to-hex-optimal-gcc
+posint-dec-to-hex-optimal-clang
+
diff --git a/morphisms/Makefile b/morphisms/Makefile
index 3912ac9..6526bf8 100644
--- a/morphisms/Makefile
+++ b/morphisms/Makefile
@@ -6,8 +6,26 @@ all: $(TARGETS)
 lib/libmorph_%.so: src/%.c
 	$(CC) -O3 -shared -o $@ -fPIC -Iinclude $<
 
-test: test.c lib/libmorph_length-prefix.so lib/libmorph_posint.so
-	$(CC) -O3 -L$(LIB_DIR) -o $@ -Iinclude $< -lmorph_length-prefix -lmorph_posint
+posint-dec-to-hex-generated-gcc: posint-dec-to-hex-generated.c
+	gcc -g -Os -flto -o $@ -Iinclude $< src/length-prefix.c src/posint.c
+
+posint-dec-to-hex-generated-clang: posint-dec-to-hex-generated.c
+	clang -g -Os -flto -o $@ -Iinclude $< src/length-prefix.c src/posint.c
+
+posint-dec-to-hex-optimal-gcc: posint-dec-to-hex-optimal.c
+	gcc -g -Os -flto -o $@ $<
+
+posint-dec-to-hex-optimal-clang: posint-dec-to-hex-optimal.c
+	clang -g -Os -flto -o $@ $<
+
+code-size-benchmark: posint-dec-to-hex-generated-gcc \
+					posint-dec-to-hex-generated-clang \
+				 	posint-dec-to-hex-optimal-gcc \
+					posint-dec-to-hex-optimal-clang
+	INST_COUNT_GEN_GCC=$(shell gdb --batch -ex "file posint-dec-to-hex-generated-gcc" -ex "disassemble main" | wc -l)
+	INST_COUNT_GEN_CLANG=$(shell gdb --batch -ex "file posint-dec-to-hex-generated-clang" -ex "disassemble main" | wc -l)
+	INST_COUNT_OPT_GCC=$(shell gdb --batch -ex "file posint-dec-to-hex-optimal-gcc" -ex "disassemble main" | wc -l)
+	INST_COUNT_OPT_CLANG=$(shell gdb --batch -ex "file posint-dec-to-hex-optimal-clang" -ex "disassemble main" | wc -l)
 
 clean:
 	rm $(TARGETS)
diff --git a/morphisms/morphism-base/length_prefix.morphism-base b/morphisms/morphism-base/length_prefix.morphism-base
index a8c13be..a5d9bd5 100644
--- a/morphisms/morphism-base/length_prefix.morphism-base
+++ b/morphisms/morphism-base/length_prefix.morphism-base
@@ -1,9 +1,9 @@
 morph_string_as_nullterm_to_length_prefix ()
-    [~<ValueDelim '\0'> Char ~ Ascii]
---> [~<LengthPrefix x86.UInt64> Char ~ Ascii]
+    <Seq~<ValueDelim '\0'> Char ~ Ascii ~ Byte>
+--> <Seq~<LengthPrefix x86.UInt64> Char ~ Ascii ~ Byte>
 @lib/libmorph_length-prefix.so:src/length_prefix.c
 
 morph_string_as_length_prefix_to_nullterm ()
-    [~<LengthPrefix x86.UInt64> Char ~ Ascii]
---> [~<ValueDelim '\0'> Char ~ Ascii]
+    <Seq~<LengthPrefix x86.UInt64> Char ~ Ascii ~ Byte>
+--> <Seq~<ValueDelim '\0'> Char ~ Ascii ~ Byte>
 @lib/libmorph_length-prefix.so:src/length_prefix.c
diff --git a/morphisms/morphism-base/posint.morphism-base b/morphisms/morphism-base/posint.morphism-base
index af1e3f1..aeb5e37 100644
--- a/morphisms/morphism-base/posint.morphism-base
+++ b/morphisms/morphism-base/posint.morphism-base
@@ -11,26 +11,26 @@ morph_digit_as_uint8_to_char (Radix:ℤ_16)
 morph_posint_radix (SrcRadix:ℤ, DstRadix:ℤ)
       ℕ
     ~ <PosInt SrcRadix LittleEndian>
-    ~ [~<LengthPrefix x86.UInt64> <Digit SrcRadix>~x86.UInt64]
+    ~ <Seq~<LengthPrefix x86.UInt64> <Digit SrcRadix>~x86.UInt64>
 -->   ℕ
     ~ <PosInt DstRadix LittleEndian>
-    ~ [~<LengthPrefix x86.UInt64> <Digit DstRadix>~x86.UInt64]
+    ~ <Seq~<LengthPrefix x86.UInt64> <Digit DstRadix>~x86.UInt64>
 @lib/libmorph-posint.so:src/posint.c
 
 morph_posint_endianness (Radix:ℤ)
       ℕ
     ~ <PosInt Radix LittleEndian>
-    ~ [~<LengthPrefix x86.UInt64> <Digit Radix> ~ x86.UInt64]
+    ~ <Seq~<LengthPrefix x86.UInt64> <Digit Radix> ~ x86.UInt64>
 -->   ℕ
     ~ <PosInt Radix BigEndian>
-    ~ [~<LengthPrefix x86.UInt64> <Digit Radix> ~ x86.UInt64]
+    ~ <Seq~<LengthPrefix x86.UInt64> <Digit Radix> ~ x86.UInt64>
 @lib/libmorph-posint.so:src/posint.c
 
 morph_posint_endianness (Radix:ℤ)
       ℕ
     ~ <PosInt Radix BigEndian>
-    ~ [~<LengthPrefix x86.UInt64> <Digit Radix> ~ x86.UInt64]
+    ~ <Seq~<LengthPrefix x86.UInt64> <Digit Radix> ~ x86.UInt64>
 -->   ℕ
     ~ <PosInt Radix LittleEndian>
-    ~ [~<LengthPrefix x86.UInt64> <Digit Radix> ~ x86.UInt64]
+    ~ <Seq~<LengthPrefix x86.UInt64> <Digit Radix> ~ x86.UInt64>
 @lib/libmorph-posint.so:src/posint.c
diff --git a/morphisms/posint-dec-to-hex-generated.c b/morphisms/posint-dec-to-hex-generated.c
new file mode 100644
index 0000000..f1aa7cf
--- /dev/null
+++ b/morphisms/posint-dec-to-hex-generated.c
@@ -0,0 +1,82 @@
+#include <stdio.h>
+#include <stdint.h>
+#include <morphisms/length-prefix.h>
+#include <morphisms/posint.h>
+
+int main() {
+    uint8_t bufA[1024];
+    uint8_t bufB[1024];
+
+    scanf("%s", bufA);
+
+    // morph to
+    //     ℕ ~ <PosInt 10 BigEndian> ~ [~<LengthPrefix x86.UInt64> <Digit 10> ~ Char ~ Ascii]
+    {
+        char const * src = (void*) bufA;
+        struct LengthPrefixUInt8Array * dst = (void*) bufB;
+        morph_string_as_nullterm_to_length_prefix( src, dst );
+    }
+
+    // morph to
+    //     ℕ ~ <PosInt 10 BigEndian> ~ [~<LengthPrefix x86.UInt64> <Digit 10> ~ ℤ_10 ~ x86.UInt64]
+    {
+        struct LengthPrefixUInt8Array * src = (void*) bufB;
+        struct LengthPrefixUInt64Array * dst = (void*) bufA;
+
+        dst->len = src->len;
+        for( uint64_t i = 0; i < src->len; ++i )
+            morph_digit_as_char_to_uint64( &src->items[i], &dst->items[i] );
+    }
+
+    // morph to
+    //    ℕ ~ <PosInt 10 LittleEndian> ~ [~<LengthPrefix x86.UInt64> <Digit 10> ~ ℤ_10 ~ x86.UInt64]
+    {
+        uint64_t const radix = 10;
+        struct LengthPrefixUInt64Array * src = (void*) bufA;
+        struct LengthPrefixUInt64Array * dst = (void*) bufB;
+        morph_posint_endianness( radix, src, dst );
+    }
+
+    // morph to
+    //    ℕ ~ <PosInt 16 LittleEndian> ~ [~<LengthPrefix x86.UInt64> <Digit 16> ~ ℤ_16 ~ x86.UInt64]
+    {
+        uint64_t const src_radix = 10;
+        uint64_t const dst_radix = 16;
+        struct LengthPrefixUInt64Array * src = (void*) bufB;
+        struct LengthPrefixUInt64Array * dst = (void*) bufA;
+        morph_posint_radix( src_radix, dst_radix, src, dst );
+    }
+
+
+    // morph to
+    //    ℕ ~ <PosInt 16 LittleEndian> ~ [~<LengthPrefix x86.UInt64> <Digit 10> ~ ℤ_10 ~ x86.UInt64]
+    {
+        uint64_t const radix = 16;
+        struct LengthPrefixUInt64Array * src = (void*) bufA;
+        struct LengthPrefixUInt64Array * dst = (void*) bufB;
+        morph_posint_endianness( radix, src, dst );
+    }
+
+    // morph to
+    //    ℕ ~ <PosInt 16 BigEndian> ~ [~<LengthPrefix x86.UInt64> <Digit 16> ~ Char ~ Ascii]
+    {
+        struct LengthPrefixUInt64Array * src = (void*) bufB;
+        struct LengthPrefixUInt8Array * dst = (void*) bufA;
+
+        dst->len = src->len;
+        for( uint64_t i = 0; i < src->len; ++i )
+            morph_digit_as_uint64_to_char( &src->items[i], &dst->items[i] );
+    }
+
+    // morph to
+    //    ℕ ~ <PosInt 16 BigEndian> ~ [~<ValueDelim '\0'> <Digit 16> ~ Char ~ Ascii]
+    {
+        struct LengthPrefixUInt8Array * src = (void*) bufA;
+        char * dst = (void*) bufB;
+        morph_string_as_length_prefix_to_nullterm( src, dst );
+    }
+
+    printf("%s\n", bufB);
+
+    return 0;
+}
diff --git a/morphisms/posint-dec-to-hex-optimal.c b/morphisms/posint-dec-to-hex-optimal.c
new file mode 100644
index 0000000..7118ae0
--- /dev/null
+++ b/morphisms/posint-dec-to-hex-optimal.c
@@ -0,0 +1,47 @@
+#include <stdio.h>
+#include <stdint.h>
+
+int main() {
+    char bufA[1024];
+    char bufB[1024];
+
+    char * in = bufA;
+    char * out = bufB;
+
+    scanf("%s", in);
+
+    uint64_t value = 0;
+    while( *in ) {
+        if( *in >= '0' && *in <= '9' ) {
+            value *= 10;
+            value += *in - '0';
+        }
+        else
+            return -1;
+
+        in++;
+    }
+
+    uint64_t v = value;
+    while( v ) {
+        out ++;
+        v /= 16;
+    }
+
+    *out-- = '\0';
+    while( value ) {
+        unsigned digit = value % 16;
+        if( digit < 10 ) {
+            *out-- = digit + '0';
+        } else if( digit < 16 ) {
+            *out-- = digit + 'a' - 10;
+        } else {
+            return -1;
+        }
+        value /= 16;
+    }
+
+    printf("%s\n", out);
+
+    return 0;
+}
diff --git a/morphisms/test.c b/morphisms/test.c
deleted file mode 100644
index 1346287..0000000
--- a/morphisms/test.c
+++ /dev/null
@@ -1,55 +0,0 @@
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <morphisms/length-prefix.h>
-#include <morphisms/posint.h>
-
-int main( int argc, char * argv[] ) {
-    char * int1 = malloc(4096);
-    struct LengthPrefixUInt8Array * int2 = malloc(4096);
-    struct LengthPrefixUInt64Array * int3 = malloc(4096);
-    struct LengthPrefixUInt64Array * int4 = malloc(4096);
-    struct LengthPrefixUInt64Array * int5 = malloc(4096);
-    struct LengthPrefixUInt64Array * int6 = malloc(4096);
-    struct LengthPrefixUInt8Array * int7 = malloc(4096);
-    char * int8 = malloc(4096);
-
-    // ℕ ~ <PosInt 10 BigEndian> ~ [~<ValueDelim '\0'> <Digit 10> ~ Char ~ Ascii]
-    scanf("%s", int1);
-
-    // morph to
-    //     ℕ ~ <PosInt 10 BigEndian> ~ [~<LengthPrefix x86.UInt64> <Digit 10> ~ Char ~ Ascii]
-    morph_string_as_nullterm_to_length_prefix( int1, int2 );
-
-    // morph to
-    //     ℕ ~ <PosInt 10 BigEndian> ~ [~<LengthPrefix x86.UInt64> <Digit 10> ~ ℤ_10 ~ x86.UInt64]
-    int3->len = int2->len;
-    for( uint64_t i = 0; i < int2->len; ++i )
-        morph_digit_as_char_to_uint64( &int2->items[i], &int3->items[i] );
-
-    // morph to
-    //    ℕ ~ <PosInt 10 LittleEndian> ~ [~<LengthPrefix x86.UInt64> <Digit 10> ~ ℤ_10 ~ x86.UInt64]
-    morph_posint_endianness( 10, int3, int4 );
-
-    // morph to
-    //    ℕ ~ <PosInt 16 LittleEndian> ~ [~<LengthPrefix x86.UInt64> <Digit 16> ~ ℤ_16 ~ x86.UInt64]
-    morph_posint_radix( 10, 16, int4, int5 );
-
-    // morph to
-    //    ℕ ~ <PosInt 16 BigEndian> ~ [~<LengthPrefix x86.UInt64> <Digit 16> ~ ℤ_16 ~ x86.UInt64]
-    morph_posint_endianness( 16, int5, int6 );
-
-    // morph to
-    //    ℕ ~ <PosInt 16 BigEndian> ~ [~<LengthPrefix x86.UInt64> <Digit 16> ~ Char ~ Ascii]
-    int7->len = int6->len;
-    for( uint64_t i = 0; i < int6->len; ++i )
-        morph_digit_as_uint64_to_char( &int6->items[i], &int7->items[i] );
-
-    // morph to
-    //    ℕ ~ <PosInt 16 BigEndian> ~ [~<ValueDelim '\0'> <Digit 16> ~ Char ~ Ascii]
-    morph_string_as_length_prefix_to_nullterm( int7, int8 );
-
-    printf("%s\n", int8);
-
-    return 0;
-}
diff --git a/src/main.rs b/src/main.rs
index bcbda32..34ddeb8 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -11,8 +11,60 @@ use {
     std::sync::{Arc, RwLock}
 };
 
+/* for a given ladder type `t`, get the corresponding C type
+ */
+pub fn get_c_repr_type(dict: &mut impl TypeDict, t: laddertypes::TypeTerm, skip_pointer: bool) -> Option<String> {
+    let lnf = t.normalize().decurry().get_lnf_vec();
+
+    match lnf.last() {
+        Some(t) => {
+            if t == &dict.parse("Byte").expect("parse")
+            || t == &dict.parse("x86.UInt8").expect("parse")
+            || t == &dict.parse("<StaticLength 8 Bit>").expect("parse")
+            {
+                Some("uint8_t".into())
+            } else if t == &dict.parse("x86.UInt16").expect("parse") {
+                Some("uint16_t".into())
+            } else if t == &dict.parse("x86.UInt32").expect("parse") {
+                Some("uint32_t".into())
+            } else if t == &dict.parse("x86.UInt64").expect("parse") {
+                Some("uint64_t".into())
+            } else {
+                match t {
+                    laddertypes::TypeTerm::App(args) => {
+                        if args[0] == laddertypes::TypeTerm::TypeID(dict.get_typeid(&"LengthPrefix".into()).unwrap())
+                        {
+                            let item_c_type : String = get_c_repr_type(dict, args[2].clone(), false)?;
+                            match item_c_type.as_str() {
+                                "uint8_t" => Some(format!("LengthPrefixUInt8Array")),
+                                "uint16_t" => Some(format!("LengthPrefixUInt16Array")),
+                                "uint32_t" => Some(format!("LengthPrefixUInt32Array")),
+                                "uint64_t" => Some(format!("LengthPrefixUInt64Array")),
+                                _ => None
+                            }
+                        }
+                        else if args[0] == laddertypes::TypeTerm::TypeID(dict.get_typeid(&"ValueDelim".into()).unwrap())
+                        {
+                            let c_type = get_c_repr_type(dict, args[2].clone(), false)?;
+                            if skip_pointer {
+                                Some(c_type)
+                            } else {
+                                Some(format!("{} *", c_type))
+                            }
+                        } else {
+                            None
+                        }
+                    }
+                    _ => None
+                }
+            }
+        }
+        None => None
+    }
+}
+
 #[derive(Debug)]
-struct Morphism {
+struct LdmcMorphism {
     symbol: String,
     type_args: Vec<(String, String)>,
     src_type: laddertypes::TypeTerm,
@@ -20,6 +72,34 @@ struct Morphism {
     locations: Vec<String>
 }
 
+impl LdmcMorphism {
+    pub fn expected_c_type_signature(&self, dict: &mut impl TypeDict) -> String {
+        format!("int {} ({} const * restrict src, {} * restrict dst);",
+            self.symbol,
+            get_c_repr_type(dict, self.src_type.clone(), true).expect("cant get c-repr type for src type"),
+            get_c_repr_type(dict, self.dst_type.clone(), true).expect("cant get c-repr type for dst type"))
+    }
+
+    pub fn generate_call(&self, dict: &mut impl TypeDict) {
+        let src_c_type = get_c_repr_type(dict, self.src_type.clone(), true).expect("cant get c-repr type for src type");
+        let dst_c_type = get_c_repr_type(dict, self.dst_type.clone(), true).expect("cant get c-repr type for dst type");
+
+        let src_buf = "bufA";
+        let dst_buf = "bufB";
+        println!(
+"{}
+    {} const * restrict src = {};
+    {} * restrict dst = {};
+    {} ( src, dst );
+{}",
+    '{',
+    src_c_type, src_buf,
+    dst_c_type, dst_buf,
+    self.symbol,
+    '}');
+    }
+}
+
 /* morphism-base text format:
  *     NAME '(' [TYPE-ARG-NAME ':' KIND]  ')'
  *           SRC-TYPE
@@ -28,7 +108,7 @@ struct Morphism {
  */
 fn parser(
     type_dict: Arc<RwLock< BimapTypeDict >>
-) -> impl Parser<char, Vec<Morphism>, Error = Simple<char>> {
+) -> impl Parser<char, Vec<LdmcMorphism>, Error = Simple<char>> {
 
     ident().padded()
     .then(
@@ -57,7 +137,7 @@ fn parser(
             let src_type = type_dict.parse(&src_type.iter().collect::<String>()).expect("couldnt parse src type");
             let dst_type = type_dict.parse(&dst_type.iter().collect::<String>()).expect("couldnt parse dst type");
 
-            Morphism {
+            LdmcMorphism {
                 symbol,
                 type_args,
                 src_type,
@@ -69,40 +149,27 @@ fn parser(
 }
 
 fn main() {
-    println!("Hello, world!");
-
-    let src = "
-        morph_digit_as_char_to_uint8 (Radix:ℤ_16)
-            <Digit Radix> ~ Char ~ Ascii ~ Byte
-        --> <Digit Radix> ~ x86.UInt8 ~ Byte
-        @lib/libmorph_posint.so:src/posint.c
-
-        morph_string_as_nullterm_to_length_prefix ()
-            <Seq~<ValueDelim '\\0'> Char ~ Ascii>
-        --> <Seq~<LengthPrefix x86.UInt64> Char ~ Ascii>
-        @lib/libmorph_length-prefix.so:src/length_prefix.c
-
-        morph_string_as_length_prefix_to_nullterm ()
-            <Seq~<LengthPrefix x86.UInt64> Char ~ Ascii>
-        --> <Seq~<ValueDelim '\\0'> Char ~ Ascii>
-        @lib/libmorph_length-prefix.so:src/length_prefix.c
-    ";
-
     let type_dict = Arc::new(RwLock::new(BimapTypeDict::new()));
 
-   let result = parser(type_dict.clone()).parse(src);
+    let src = std::fs::read_to_string(
+        std::env::args().nth(1).expect("expected file name")
+    ).expect("read");
 
+    let result = parser(type_dict.clone()).parse(src.clone());
     match result {
         Ok(morphisms) => {
             println!("parse ok.");
-
             let mut dict = type_dict.write().unwrap();
 
             for m in morphisms {
-                println!("{}\n    {}\n---> \n    {}\n", m.symbol,
-                    m.src_type.normalize().sugar(&mut *dict).pretty(&mut *dict, 1),
-                    m.dst_type.normalize().sugar(&mut *dict).pretty(&mut *dict, 1),
+                println!("{}\n    {}\n---> \n    {}\n{}\n\n", m.symbol,
+                    m.src_type.clone().sugar(&mut *dict).pretty(&mut *dict, 1),
+                    m.dst_type.clone().sugar(&mut *dict).pretty(&mut *dict, 1),
+
+                    m.expected_c_type_signature(&mut *dict),
                 );
+
+                m.generate_call(&mut *dict);
             }
         }
         Err(errs) => {