From 85c8593e298d6bbed35ca661fcd55f5f5c3216a8 Mon Sep 17 00:00:00 2001
From: Bryan English <bryan@rethought.computer>
Date: Tue, 27 Jan 2026 23:50:38 -0500
Subject: [PATCH] comments in asm

---
 hylo-lang/hyloc/src/riscv_asm_codegen.rs | 23 ++++++++++++++++++-----
 1 file changed, 18 insertions(+), 5 deletions(-)

diff --git a/hylo-lang/hyloc/src/riscv_asm_codegen.rs b/hylo-lang/hyloc/src/riscv_asm_codegen.rs
index ca3cd99..4fa4be3 100644
--- a/hylo-lang/hyloc/src/riscv_asm_codegen.rs
+++ b/hylo-lang/hyloc/src/riscv_asm_codegen.rs
@@ -118,7 +118,7 @@ impl<'a> CodeGen<'a> {
         self.label(".data\n");
         self.label("data_stack:");
         self.line(format!(".space {}", self.data_stack_size));
-        self.label("data_stack_end:");
+        self.label(".globl data_stack_end\ndata_stack_end:\n");
 
         // Code
         self.label(".text\n");
@@ -136,20 +136,22 @@ impl<'a> CodeGen<'a> {
                     if name == "main" {
                         self.label(".globl _start"); // TODO is globl necessary?
                         self.label("_start:");
-                        self.line("la s2, data_stack_end"); // set stack pointer
+                        self.line("la s2, data_stack_end # set initial data stack pointer");
                     } else {
                         self.label(format!(".globl {}", name));
                         self.label(format!("{}:", name));
                     }
-                    self.line("addi sp, sp, -16"); // allocate 16 bytes on stack
-                    self.line("sw ra, 8(sp)");   // store return address on stack
+                    self.line("addi sp, sp, -16 # allocate 16 bytes on stack"); // allocate 16 bytes on stack
+                    self.line("sw ra, 8(sp) # store return address on stack");   // store return address on stack
                 },
                 IR::Call(name) => {
+                    self.label(format!("# call {}", name));
+
                     self.line(format!("call {}", name));    
                 },
                 IR::Ret => {
                     if last_label == "main" {
-                        // exit 0 syscall
+                        self.label("# exit 0 syscall");
                         self.line("li a7, 93");
                         self.line("mv a0, x0");
                         self.line("ecall");
@@ -171,17 +173,21 @@ impl<'a> CodeGen<'a> {
                     self.move_stack_ptr_by_cells(2);
                 },
                 IR::StackPush(num) => {
+                    self.label(format!("# stackpush {}", num));
                     self.line(format!("li t0, {}", num));
                     self.push_from("t0");
                 },
                 IR::StackPushString(name) => {
+                    self.label(format!("# stackpushstring {}", name));
                     self.line(format!("li t0, {}", name));
                     self.push_from("t0");
                 },
                 IR::AddU64 => {
+                    self.label("# add");
                     self.pop_call_push("t0 t1", "add t0, t0, t1", "t0"); 
                 },
                 IR::SubtractU64 => {
+                    self.label("# sub");
                     self.pop_call_push("t0 t1", "sub t0, t0, t1", "t0"); 
                 },
                 IR::MultiplyU64 => {
@@ -194,15 +200,18 @@ impl<'a> CodeGen<'a> {
                     self.pop_call_push("t0 t1", "rem t0, t0, t1", "t0"); 
                 },
                 IR::Dup => {
+                    self.label("# dup");
                     self.copy_top_stack_value_to("t0");
                     self.push_from("t0");
                 },
                 IR::Swap => {
+                    self.label("# swap");
                     self.pop_some_to("t1 t0");
                     self.push_from("t0");
                     self.push_from("t1");
                 },
                 IR::Drop => {
+                    self.label("# drop");
                     self.move_stack_ptr_by_cells(1);
                 },
                 IR::Equals => {
@@ -211,6 +220,7 @@ impl<'a> CodeGen<'a> {
                     self.pop_call_push("t0 t1", "sub t0, t0, t1", "t0"); 
                 },
                 IR::GreaterThan => {
+                    self.label("# >");
                     self.pop_some_to("t0 t1");
                     self.line("sgt  t0, t0, t1");
                     self.line("seqz t0, t0"); // remember, 0 is true, others are false
@@ -245,18 +255,21 @@ impl<'a> CodeGen<'a> {
                 },
                 // https://cmput229.github.io/229-labs-RISCV/RISC-V-Examples_Public/03-Conditionals/03b-If_Else.html
                 IR::If => {
+                    self.label("# if");
                     self.pop_to("t0");
                     self.line(format!("bnez t0, _else_{}", if_block_count));
                     if_stack.push(if_block_count);
                     if_block_count += 1;
                 },
                 IR::Else => {
+                    self.label("# else");
                     let if_counter = if_stack.last().unwrap().clone();
                     self.line(format!("j _endif_{}", if_counter));
                     self.label(format!("_else_{}:", if_counter));
                     seen_else.insert(if_counter);
                 },
                 IR::EndIf => {
+                    self.label("# endif");
                     let stack = &mut if_stack;
                     let if_counter = stack.last().unwrap().clone();
                     if !seen_else.contains(&if_counter) {
-- 
2.43.0