From 87a210919c51093879604720e3030a8814377246 Mon Sep 17 00:00:00 2001
From: Lucas Clemente Vella <lucas.vella@powdrlabs.com>
Date: Mon, 29 Jan 2024 19:33:27 +0000
Subject: [PATCH] In off(reg) syntax, makes register optinal, defaulting to x0.

---
 riscv/src/compiler.rs | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/riscv/src/compiler.rs b/riscv/src/compiler.rs
index 8987f578e..cbe5eb718 100644
--- a/riscv/src/compiler.rs
+++ b/riscv/src/compiler.rs
@@ -885,6 +885,10 @@ fn rro(args: &[Argument]) -> (Register, Register, u32) {
             *r2,
             expression_to_number(off.as_ref().unwrap_or(&Expression::Number(0))),
         ),
+        [Argument::Register(r1), Argument::Expression(off)] => {
+            // If the register is not specified, it defaults to x0
+            (*r1, Register::new(0), expression_to_number(off))
+        }
         _ => panic!(),
     }
 }
@@ -897,6 +901,10 @@ fn rrro(args: &[Argument]) -> (Register, Register, Register, u32) {
             *r3,
             expression_to_number(off.as_ref().unwrap_or(&Expression::Number(0))),
         ),
+        [Argument::Register(r1), Argument::Register(r2), Argument::Expression(off)] => {
+            // If the register is not specified, it defaults to x0
+            (*r1, *r2, Register::new(0), expression_to_number(off))
+        }
         _ => panic!(),
     }
 }