From 4965493a0eeec5f717a3fb035c095c853fe1a19e Mon Sep 17 00:00:00 2001
From: Noratrieb <48135649+Noratrieb@users.noreply.github.com>
Date: Mon, 10 Mar 2025 19:48:09 +0100
Subject: [PATCH] fix c.addi16sp

---
 src/emu.rs    | 41 +++++++++++++++++++++++++++++++++++++----
 src/inst.rs   |  9 ++++++---
 test/Makefile |  3 +++
 test/init1.rs |  9 ---------
 4 files changed, 46 insertions(+), 16 deletions(-)

diff --git a/src/emu.rs b/src/emu.rs
index 83dcd2e..0b10ee7 100644
--- a/src/emu.rs
+++ b/src/emu.rs
@@ -150,10 +150,33 @@ impl Display for Reg {
     }
 }
 
+fn hash_color(value: u32) -> impl Display {
+    use owo_colors::*;
+    use std::hash::{Hash, Hasher};
+    let mut w = std::collections::hash_map::DefaultHasher::new();
+    value.hash(&mut w);
+    let hash = w.finish();
+    let arr = [
+        AnsiColors::Black,
+        AnsiColors::Red,
+        AnsiColors::Green,
+        AnsiColors::Yellow,
+        AnsiColors::Blue,
+        AnsiColors::Magenta,
+        AnsiColors::Cyan,
+        AnsiColors::White,
+        AnsiColors::Default,
+    ];
+    format!(
+        "{}",
+        format!("{value:x}").color(arr[(hash % arr.len() as u64) as usize])
+    )
+}
+
 impl Emulator {
     pub fn start_linux(&mut self) -> Status {
         // set top of stack. just some yolo address. with no values there. who needs abi?
-        self[Reg::SP] = 4096;
+        self[Reg::SP] = 4096 * 8;
 
         self.execute()
     }
@@ -180,7 +203,15 @@ impl Emulator {
         }
 
         if self.debug {
-            println!("executing 0x{:x} {inst:?}", self.pc);
+            println!(
+                "0x{:x} {} (sp: {}) {inst:?}",
+                self.pc,
+                match was_compressed {
+                    IsCompressed::Yes => "C",
+                    IsCompressed::No => " ",
+                },
+                hash_color(self.xreg[Reg::SP.0 as usize])
+            );
         }
 
         let next_pc = self.pc.wrapping_add(match was_compressed {
@@ -435,7 +466,7 @@ impl Emulator {
         Ok(())
     }
 
-    fn debug_interactive(&mut self) {
+    pub fn debug_interactive(&mut self) {
         use owo_colors::OwoColorize;
         loop {
             print!("> ");
@@ -451,6 +482,7 @@ impl Emulator {
                 "s" => {
                     return;
                 }
+                "q" => std::process::exit(0),
                 "p" => {
                     let format_value = |v: u32| {
                         if v == 0 {
@@ -554,7 +586,8 @@ impl Emulator {
 - ?: help
 - p: print registers
 - c: continue until next breakpoint
-- s: step one instruction"
+- s: step one instruction
+- q: quit"
                 ),
             }
         }
diff --git a/src/inst.rs b/src/inst.rs
index 782dbb8..0d73d34 100644
--- a/src/inst.rs
+++ b/src/inst.rs
@@ -224,7 +224,11 @@ impl Display for Inst {
                 }
             }
             Inst::Jalr { offset, base, dest } => {
-                write!(f, "jalr {dest}, {}({base})", offset as i32)
+                if dest == Reg::ZERO && offset == 0 && base == Reg::RA {
+                    write!(f, "ret")
+                } else {
+                    write!(f, "jalr {dest}, {}({base})", offset as i32)
+                }
             }
             Inst::Beq { offset, src1, src2 } => write!(f, "beq {src1}, {src2}, {}", offset as i32),
             Inst::Bne { offset, src1, src2 } => write!(f, "bne {src1}, {src2}, {}", offset as i32),
@@ -554,7 +558,6 @@ impl Inst {
         if code.0 == 0 {
             return Err(Status::IllegalInstruction(code.into(), "null instruction"));
         }
-
         let inst = match code.quadrant() {
             // C0
             0b00 => match code.funct3() {
@@ -695,7 +698,7 @@ impl Inst {
                         // C.ADDI16SP -> addi sp, sp, \imm
                         2 => Inst::Addi {
                             imm: code.immediate_s(&[
-                                (2..=2, 2),
+                                (2..=2, 5),
                                 (3..=4, 7),
                                 (5..=5, 6),
                                 (6..=6, 4),
diff --git a/test/Makefile b/test/Makefile
index 086da9e..1910c02 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -10,3 +10,6 @@ init: init.c
 
 init1: init1.rs
 	$(RUSTC) init1.rs
+
+x: x.S
+	$(CC_STATIC) x.S -o x
diff --git a/test/init1.rs b/test/init1.rs
index c22f5c7..aa6047b 100644
--- a/test/init1.rs
+++ b/test/init1.rs
@@ -93,19 +93,10 @@ fn input() -> u64 {
     }
 }
 
-fn x(a: i32) {}
-
-
 #[no_mangle]
 fn _start() -> ! {
-    x(0);
-    x(0);
-    exit(0);
     let random_number = 45;
 
-    let num = core::sync::atomic::AtomicI32::new(0);
-    num.swap(10, core::sync::atomic::Ordering::SeqCst);
-
     loop {
         let n = input();
         if n == random_number {