unit::alu_branch::add_sub: bug fix: actually add in carry_in

crates/cpu/src/unit/alu_branch.rs

@@ -87,8 +87,11 @@ fn add_sub<C: Type + PhantomConstCpuConfig, SrcCount: KnownSize>(config: C) {
         connect(src1, src_values[1].int_fp);
     }
     #[hdl]
-    let carry_in = wire();
-    connect(carry_in, carry_in_before_inversion ^ invert_carry_in);
+    let carry_in: UInt<1> = wire();
+    connect(
+        carry_in,
+        (carry_in_before_inversion ^ invert_carry_in).cast_to_static::<UInt<1>>(),
+    );
     #[hdl]
     let src0 = wire();
     connect(src0, src_values[0].int_fp);
@@ -104,7 +107,12 @@ fn add_sub<C: Type + PhantomConstCpuConfig, SrcCount: KnownSize>(config: C) {
         connect(pc_or_zero, pc);
     }
     let sum_of_sliced = |slice: RangeTo<usize>| {
-        src0[slice] + src1[slice] + src_values[2].int_fp[slice] + pc_or_zero[slice] + imm[slice]
+        src0[slice]
+            + src1[slice]
+            + src_values[2].int_fp[slice]
+            + pc_or_zero[slice]
+            + imm[slice]
+            + carry_in
     };
     #[hdl]
     let sum: UInt<64> = wire();