From 78c43b5f0e39c5053384adf73d55303018e64893 Mon Sep 17 00:00:00 2001
From: Matthias Goergens <matthias.goergens@gmail.com>
Date: Thu, 12 Dec 2024 11:01:28 +0800
Subject: [PATCH] Cleaned up

---
 ceno_zkvm/src/instructions/riscv/ecall/halt.rs | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/ceno_zkvm/src/instructions/riscv/ecall/halt.rs b/ceno_zkvm/src/instructions/riscv/ecall/halt.rs
index 3d3e2ec75..eb5c0849d 100644
--- a/ceno_zkvm/src/instructions/riscv/ecall/halt.rs
+++ b/ceno_zkvm/src/instructions/riscv/ecall/halt.rs
@@ -2,7 +2,7 @@ use crate::{
     chip_handler::RegisterChipOperations,
     circuit_builder::CircuitBuilder,
     error::ZKVMError,
-    expression::{Expression, ToExpr, WitIn},
+    expression::{ToExpr, WitIn},
     gadgets::AssertLTConfig,
     instructions::{
         Instruction,
@@ -51,8 +51,7 @@ impl<E: ExtensionField> Instruction<E> for HaltInstruction<E> {
         // read exit_code from arg0 (X10 register)
         let (_, lt_x10_cfg) = cb.register_read(
             || "read x10",
-            // TODO(Matthias): clean up.
-            &Expression::Constant(E::BaseField::from(ceno_emul::Platform::reg_arg0() as u64)),
+            ceno_emul::Platform::reg_arg0(),
             prev_x10_ts,
             ecall_cfg.ts.expr() + Tracer::SUBCYCLE_RS2,
             exit_code,