From d6daad93a4b2cf2575c334d09fcf83edc557a53c Mon Sep 17 00:00:00 2001
From: Xavier Leroy <xavier.leroy@college-de-france.fr>
Date: Tue, 30 Dec 2025 09:37:12 +0100
Subject: [PATCH 1/3] Ceval.binop: add missing casts to `tyop`

The arguments must always be converted to `tyop` before the comparison is done.

Fixes: #565
---
 cparser/Ceval.ml | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/cparser/Ceval.ml b/cparser/Ceval.ml
index 0800e25ba2..7fdc400632 100644
--- a/cparser/Ceval.ml
+++ b/cparser/Ceval.ml
@@ -122,9 +122,10 @@ let unop env op tyres ty v =
   in cast env ty res
 
 let comparison env direction ptraction tyop v1 v2 =
-  (* tyop = type at which the comparison is done *)
+  (* tyop = type at which the comparison is done.
+     v1, v2 have been converted to tyop already. *)
   let b =
-    match cast env tyop v1, cast env tyop v2 with
+    match v1, v2 with
     | I n1, I n2 ->
         if is_signed env tyop
         then direction (compare n1 n2) 0
@@ -140,29 +141,31 @@ let comparison env direction ptraction tyop v1 v2 =
 let binop env op tyop tyres ty1 v1 ty2 v2 =
   (* tyop = type at which the computation is done
      tyres = expected result type *)
+  let v1 = cast env tyop v1
+  and v2 = cast env tyop v2 in
   let res =
     match op with
     | Oadd ->
         if is_arith_type env ty1 && is_arith_type env ty2 then begin
-          match cast env tyop v1, cast env tyop v2 with
+          match v1, v2 with
           | I n1, I n2 -> I (Int64.add n1 n2)
           | _, _ -> raise Notconst
         end else
           raise Notconst
     | Osub ->
         if is_arith_type env ty1 && is_arith_type env ty2 then begin
-          match cast env tyop v1, cast env tyop v2 with
+          match v1, v2 with
           | I n1, I n2 -> I (Int64.sub n1 n2)
           | _, _ -> raise Notconst
         end else
           raise Notconst
     | Omul ->
-        begin match cast env tyop v1, cast env tyop v2 with
+        begin match v1, v2 with
           | I n1, I n2 -> I (Int64.mul n1 n2)
           | _, _ -> raise Notconst
         end
     | Odiv ->
-        begin match cast env tyop v1, cast env tyop v2 with
+        begin match v1, v2 with
           | I n1, I n2 ->
               if n2 = 0L then raise Notconst else
               if is_signed env tyop then I (Int64.div n1 n2)

From 1e449f2d42de1b58aa52ac65c2fda513ca6b2dc8 Mon Sep 17 00:00:00 2001
From: Xavier Leroy <xavier.leroy@college-de-france.fr>
Date: Tue, 30 Dec 2025 09:39:36 +0100
Subject: [PATCH 2/3] Ceval.unop: wrong cast of result value

Fixes: #565
---
 cparser/Ceval.ml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cparser/Ceval.ml b/cparser/Ceval.ml
index 7fdc400632..052fbdeba2 100644
--- a/cparser/Ceval.ml
+++ b/cparser/Ceval.ml
@@ -119,7 +119,7 @@ let unop env op tyres ty v =
    | Olognot, _, _ -> if boolean_value v then I 0L else I 1L
    | Onot, _, I n -> I (Int64.lognot n)
    | _ -> raise Notconst
-  in cast env ty res
+  in cast env tyres res
 
 let comparison env direction ptraction tyop v1 v2 =
   (* tyop = type at which the comparison is done.

From 23b1f34de2cf74eed70a3191cfe471fd1e6e5acd Mon Sep 17 00:00:00 2001
From: Xavier Leroy <xavier.leroy@college-de-france.fr>
Date: Tue, 30 Dec 2025 10:32:58 +0100
Subject: [PATCH 3/3] Update small test suite

---
 test | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test b/test
index ddb2ea33a7..081175df37 160000
--- a/test
+++ b/test
@@ -1 +1 @@
-Subproject commit ddb2ea33a776bb576edb79a4476b06280087fb84
+Subproject commit 081175df374260304a5cd78dd3dfaded93dceb41