From 8a381e5ef1de9f0d44ddea6f592e5f587f3633fa Mon Sep 17 00:00:00 2001
From: Ulf Norell <ulf.norell@gmail.com>
Date: Thu, 25 Apr 2019 16:06:50 +0200
Subject: [PATCH] Support equality on bytes(N)

---
 src/aeso_ast_to_icode.erl         | 22 ++++++++++++++++++----
 test/aeso_compiler_tests.erl      |  3 ++-
 test/contracts/bytes_equality.aes | 18 ++++++++++++++++++
 3 files changed, 38 insertions(+), 5 deletions(-)
 create mode 100644 test/contracts/bytes_equality.aes

diff --git a/src/aeso_ast_to_icode.erl b/src/aeso_ast_to_icode.erl
index 62dc31a..bb7447a 100644
--- a/src/aeso_ast_to_icode.erl
+++ b/src/aeso_ast_to_icode.erl
@@ -579,15 +579,29 @@ ast_binop(Op, Ann, {typed, _, A, Type}, B, Icode)
         _ when not Monomorphic ->
             gen_error({cant_compare_polymorphic_type, Ann, Op, Type});
         word   -> #binop{op = Op, left = ast_body(A, Icode), right = ast_body(B, Icode)};
-        string ->
+        OtherType ->
             Neg = case Op of
                     '==' -> fun(X) -> X end;
                     '!=' -> fun(X) -> #unop{ op = '!', rand = X } end;
                     _    -> gen_error({cant_compare, Ann, Op, Type})
                   end,
-            Neg(#funcall{ function = #var_ref{name = {builtin, str_equal}},
-                          args     = [ast_body(A, Icode), ast_body(B, Icode)] });
-        _ -> gen_error({cant_compare, Ann, Op, Type})
+            Args = [ast_body(A, Icode), ast_body(B, Icode)],
+            Builtin =
+                case OtherType of
+                    string ->
+                        #funcall{ function = #var_ref{name = {builtin, str_equal}},
+                                  args     = Args };
+                    {tuple, Types} ->
+                        case lists:usort(Types) of
+                            [word] ->
+                                #funcall{ function = #var_ref{name = {builtin, str_equal_p}},
+                                          args = [ #integer{value = 32 * length(Types)} | Args] };
+                            _ -> gen_error({cant_compare, Ann, Op, Type})
+                        end;
+                    _ ->
+                        gen_error({cant_compare, Ann, Op, Type})
+                end,
+            Neg(Builtin)
     end;
 ast_binop('++', _, A, B, Icode) ->
     #funcall{ function = #var_ref{ name = {builtin, list_concat} },
diff --git a/test/aeso_compiler_tests.erl b/test/aeso_compiler_tests.erl
index 320a5fb..7bcda3d 100644
--- a/test/aeso_compiler_tests.erl
+++ b/test/aeso_compiler_tests.erl
@@ -106,7 +106,8 @@ compilable_contracts() ->
      "include",
      "basic_auth",
      "bitcoin_auth",
-     "address_literals"
+     "address_literals",
+     "bytes_equality"
     ].
 
 %% Contracts that should produce type errors
diff --git a/test/contracts/bytes_equality.aes b/test/contracts/bytes_equality.aes
new file mode 100644
index 0000000..cd0165b
--- /dev/null
+++ b/test/contracts/bytes_equality.aes
@@ -0,0 +1,18 @@
+
+contract BytesEquality =
+
+  function eq16(a : bytes(16), b) = a == b
+  function ne16(a : bytes(16), b) = a != b
+
+  function eq32(a : bytes(32), b) = a == b
+  function ne32(a : bytes(32), b) = a != b
+
+  function eq47(a : bytes(47), b) = a == b
+  function ne47(a : bytes(47), b) = a != b
+
+  function eq64(a : bytes(64), b) = a == b
+  function ne64(a : bytes(64), b) = a != b
+
+  function eq65(a : bytes(65), b) = a == b
+  function ne65(a : bytes(65), b) = a != b
+