feat: add support for booleans and comparision operators

src/backend/cranelift.rs

@@ -192,6 +192,14 @@ impl<'a> FunctionTranslator<'a> {
                 let inner_val = self.translate_expr(inner);
                 match op {
                     UnaryOp::Neg => self.builder.ins().ineg(inner_val),
+                    UnaryOp::Not => {
+                        // `!x` is equivalent to `x == 0` for booleans (0 or 1).
+                        let ty = CraneliftBackend::lower_type(&inner.ty);
+                        let zero = self.builder.ins().iconst(ty, 0);
+                        self.builder
+                            .ins()
+                            .icmp(ir::condcodes::IntCC::Equal, inner_val, zero)
+                    }
                 }
             }
             TypedExprKind::Binary { op, lhs, rhs } => {
@@ -218,6 +226,48 @@ impl<'a> FunctionTranslator<'a> {
                             self.builder.ins().urem(lhs_val, rhs_val)
                         }
                     }
+                    BinaryOp::Eq => {
+                        self.builder
+                            .ins()
+                            .icmp(ir::condcodes::IntCC::Equal, lhs_val, rhs_val)
+                    }
+                    BinaryOp::Neq => {
+                        self.builder
+                            .ins()
+                            .icmp(ir::condcodes::IntCC::NotEqual, lhs_val, rhs_val)
+                    }
+                    BinaryOp::Lt => {
+                        let cc = if is_signed {
+                            ir::condcodes::IntCC::SignedLessThan
+                        } else {
+                            ir::condcodes::IntCC::UnsignedLessThan
+                        };
+                        self.builder.ins().icmp(cc, lhs_val, rhs_val)
+                    }
+                    BinaryOp::Le => {
+                        let cc = if is_signed {
+                            ir::condcodes::IntCC::SignedLessThanOrEqual
+                        } else {
+                            ir::condcodes::IntCC::UnsignedLessThanOrEqual
+                        };
+                        self.builder.ins().icmp(cc, lhs_val, rhs_val)
+                    }
+                    BinaryOp::Gt => {
+                        let cc = if is_signed {
+                            ir::condcodes::IntCC::SignedGreaterThan
+                        } else {
+                            ir::condcodes::IntCC::UnsignedGreaterThan
+                        };
+                        self.builder.ins().icmp(cc, lhs_val, rhs_val)
+                    }
+                    BinaryOp::Ge => {
+                        let cc = if is_signed {
+                            ir::condcodes::IntCC::SignedGreaterThanOrEqual
+                        } else {
+                            ir::condcodes::IntCC::UnsignedGreaterThanOrEqual
+                        };
+                        self.builder.ins().icmp(cc, lhs_val, rhs_val)
+                    }
                 }
             }
         }