compile.scm serialization: emit 32bit-format header when possible

miniml/compiler/compile.scm

@@ -1167,13 +1167,27 @@
        ))
      (emit-header (lambda ()
        ; we assume that 'count' ran first to initialize len, objcount, size32, size64
-       (bytecode-put-u32 #x8495A6BF) ; Intext_magic_number_big
-       (bytecode-put-u32 0)          ; Unused
-       (bytecode-put-u64 len)
-       (bytecode-put-u64 objcount)   ; note: always 0, as objects are not used in the bytecode-object format
-       (bytecode-put-u64 size64)
+       (cond
+        ((and
+          (fits-unsigned 32 len)
+          (fits-unsigned 32 size32)
+          (fits-unsigned 32 size64)
+         )
+           (bytecode-put-u32 #x8495A6BE) ; Intext_magic_number_small
+           (bytecode-put-u32 len)
+           (bytecode-put-u32 objcount)   ; note: always 0, as objects are not used in the bytecode-object format
+           (bytecode-put-u32 size32)
+           (bytecode-put-u32 size64)
+        )
+        (else
+           (bytecode-put-u32 #x8495A6BF) ; Intext_magic_number_big
+           (bytecode-put-u32 0)          ; Unused
+           (bytecode-put-u64 len)
+           (bytecode-put-u64 objcount)
+           (bytecode-put-u64 size64)
        ))
-     )
+     ))
+  )
   (begin
     (count value)
     (emit-header)

miniml/compiler/test/arith.info.reference

@@ -1 +1 @@
-Bytecode size:    7624 bytes
+Bytecode size:    7600 bytes

miniml/compiler/test/empty.info.reference

@@ -1 +1 @@
-Bytecode size:    5044 bytes
+Bytecode size:    5020 bytes

miniml/compiler/test/exceptions.info.reference

@@ -1 +1 @@
-Bytecode size:   10060 bytes
+Bytecode size:   10036 bytes

miniml/compiler/test/exits.info.reference

@@ -1 +1 @@
-Bytecode size:    7920 bytes
+Bytecode size:    7896 bytes

miniml/compiler/test/external_exceptions.info.reference

@@ -1 +1 @@
-Bytecode size:   10622 bytes
+Bytecode size:   10598 bytes

miniml/compiler/test/functions.info.reference

@@ -1 +1 @@
-Bytecode size:    9316 bytes
+Bytecode size:    9292 bytes

miniml/compiler/test/functors.info.reference

@@ -1 +1 @@
-Bytecode size:    6183 bytes
+Bytecode size:    6159 bytes

miniml/compiler/test/infix_sugar.info.reference

@@ -1 +1 @@
-Bytecode size:    5613 bytes
+Bytecode size:    5589 bytes

miniml/compiler/test/labels.info.reference

@@ -1 +1 @@
-Bytecode size:    6704 bytes
+Bytecode size:    6680 bytes

miniml/compiler/test/let_open.info.reference

@@ -1 +1 @@
-Bytecode size:    6327 bytes
+Bytecode size:    6303 bytes

miniml/compiler/test/lists.info.reference

@@ -1 +1 @@
-Bytecode size:    7883 bytes
+Bytecode size:    7859 bytes

miniml/compiler/test/loops.info.reference

@@ -1 +1 @@
-Bytecode size:    6862 bytes
+Bytecode size:    6838 bytes

miniml/compiler/test/patterns.info.reference

@@ -1 +1 @@
-Bytecode size:   17753 bytes
+Bytecode size:   17729 bytes

miniml/compiler/test/records.info.reference

@@ -1 +1 @@
-Bytecode size:    7311 bytes
+Bytecode size:    7287 bytes