When flen is a constant, use the constant integer value instead of flen expr.

diff --git a/pa_bitmatch.ml b/pa_bitmatch.ml
index 1e3225c..d8698e2 100644 (file)
--- a/pa_bitmatch.ml
+++ b/pa_bitmatch.ml
@@ -303,7 +303,7 @@ let output_constructor _loc fields =
            exn_used := true;
 
            <:expr<
-             Bitmatch.$lid:construct_func$ $lid:buffer$ $fexpr$ $flen$
+             Bitmatch.$lid:construct_func$ $lid:buffer$ $fexpr$ $`int:i$
                $lid:exn$
            >>
 
@@ -335,9 +335,10 @@ let output_constructor _loc fields =
         (* String, constant length > 0, must be a multiple of 8. *)
        | String, Some i when i > 0 && i land 7 = 0 ->
            let bs = gensym "bs" in
+           let j = i lsr 3 in
            <:expr<
              let $lid:bs$ = $fexpr$ in
-             if String.length $lid:bs$ = ($flen$ lsr 3) then
+             if String.length $lid:bs$ = $`int:j$ then
                Bitmatch.construct_string $lid:buffer$ $lid:bs$
              else
                raise (Bitmatch.Construct_failure
@@ -394,7 +395,7 @@ let output_constructor _loc fields =
            let bs = gensym "bs" in
            <:expr<
              let $lid:bs$ = $fexpr$ in
-             if Bitmatch.bitstring_length $lid:bs$ = $flen$ then
+             if Bitmatch.bitstring_length $lid:bs$ = $`int:i$ then
                Bitmatch.construct_bitstring $lid:buffer$ $lid:bs$
              else
                raise (Bitmatch.Construct_failure
@@ -561,10 +562,10 @@ let output_bitmatch _loc bs cases =
              let extract_func = name_of_int_extract_const (i,endian,signed) in
              let v = gensym "val" in
              <:expr<
-               if $lid:len$ >= $flen$ then (
+               if $lid:len$ >= $`int:i$ then (
                  let $lid:v$, $lid:off$, $lid:len$ =
                    Bitmatch.$lid:extract_func$ $lid:data$ $lid:off$ $lid:len$
-                     $flen$ in
+                     $`int:i$ in
                  match $lid:v$ with $fpatt$ when true -> $inner$ | _ -> ()
                )
              >>
@@ -592,10 +593,10 @@ let output_bitmatch _loc bs cases =
          | String, Some i when i > 0 && i land 7 = 0 ->
              let bs = gensym "bs" in
              <:expr<
-               if $lid:len$ >= $flen$ then (
+               if $lid:len$ >= $`int:i$ then (
                  let $lid:bs$, $lid:off$, $lid:len$ =
                    Bitmatch.extract_bitstring $lid:data$ $lid:off$ $lid:len$
-                     $flen$ in
+                     $`int:i$ in
                  match Bitmatch.string_of_bitstring $lid:bs$ with
                  | $fpatt$ when true -> $inner$
                  | _ -> ()
@@ -648,10 +649,10 @@ let output_bitmatch _loc bs cases =
                    Loc.raise _loc
                      (Failure "cannot compare a bitstring to a constant") in
              <:expr<
-               if $lid:len$ >= $flen$ then (
+               if $lid:len$ >= $`int:i$ then (
                  let $lid:ident$, $lid:off$, $lid:len$ =
                    Bitmatch.extract_bitstring $lid:data$ $lid:off$ $lid:len$
-                     $flen$ in
+                     $`int:i$ in
                  $inner$
                )
              >>