From d8642bfe0ac9ab578d4f8a0a7e3a16ca4110614e Mon Sep 17 00:00:00 2001
From: luccie <luccie@sideros.org>
Date: Sun, 10 Aug 2025 22:52:04 +0200
Subject: [PATCH] [MODS/IR]: Fix a bug in fix_branches_for_block

---
 src/mods/ir.zig | 8 +++-----
 src/mods/vm.zig | 9 +++++----
 src/sideros.zig | 4 ++--
 3 files changed, 10 insertions(+), 11 deletions(-)

diff --git a/src/mods/ir.zig b/src/mods/ir.zig
index 48a6700..a6624db 100644
--- a/src/mods/ir.zig
+++ b/src/mods/ir.zig
@@ -630,7 +630,6 @@ const IRParserState = struct {
             0x02...0x03 => self.parseBlock(b),
             0x04 => self.parseIf(),
             0x0C...0x0D => self.parseBranch(b),
-            // 0x0E => self.parseTableBranch(b),
             0x0E => self.parseBrTable(b),
             0x0F => self.push(@enumFromInt(b), .{ .u64 = 0 }),
             0x10 => self.push(@enumFromInt(b), .{ .u32 = try self.parser.readU32() }),
@@ -793,14 +792,12 @@ const IRParserState = struct {
         var todel: std.ArrayListUnmanaged(u32) = .{};
         defer todel.deinit(self.allocator);
 
-        var idx: u32 = 0;
-        for (self.branches.items) |branch| {
+        for (self.branches.items, 0..) |branch, idx| {
             if (start <= branch.pc and branch.pc < end) {
                 const ptr = if (branch.table) &self.br_table_vectors.items[branch.index] else &self.indices.items[branch.index].u32;
                 if (ptr.* == 0) {
                     ptr.* = jump_addr;
                     try todel.append(self.allocator, @intCast(idx));
-                    idx += 1;
                 } else {
                     ptr.* -= 1;
                 }
@@ -863,7 +860,8 @@ pub fn parse(parser: *Parser) !IR {
         .allocator = parser.allocator,
     };
     try state.parseFunction();
-    // if (state.branches.count() != 0) return Parser.Error.unresolved_branch;
+    std.debug.print("Br length: {d}\n", .{state.branches.items.len});
+    if (state.branches.items.len != 0) return Parser.Error.unresolved_branch;
     return .{
         .opcodes = try state.opcodes.toOwnedSlice(state.allocator),
         .indices = try state.indices.toOwnedSlice(state.allocator),
diff --git a/src/mods/vm.zig b/src/mods/vm.zig
index 24e08ae..9e3e2a0 100644
--- a/src/mods/vm.zig
+++ b/src/mods/vm.zig
@@ -123,7 +123,7 @@ pub const Runtime = struct {
         loop: while (frame.program_counter < frame.code.opcodes.len) {
             const opcode: IR.Opcode = frame.code.opcodes[frame.program_counter];
             const index = frame.code.indices[frame.program_counter];
-            // std.debug.print("Executing at {X} {any} \n", .{frame.program_counter, opcode});
+            std.debug.print("Executing at {X} {any} {X}\n", .{frame.program_counter, opcode, if (opcode == IR.Opcode.br_if) @as(i64, @intCast(index.u32)) else -1});
             switch (opcode) {
                 .@"unreachable" => {
                     std.debug.panic("Reached unreachable statement at IR counter {any}\n", .{frame.program_counter});
@@ -134,7 +134,7 @@ pub const Runtime = struct {
                     continue;
                 },
                 .br_if => {
-                    if (self.stack.items[self.stack.items.len - 1].i32 != 0) {
+                    if (self.stack.pop().?.i32 != 0) {
                         frame.program_counter = index.u32;
                         continue;
                     }
@@ -408,7 +408,7 @@ pub const Runtime = struct {
                 .i64_lt_u => {
                     const a = @as(u64, @intCast(self.stack.pop().?.i64));
                     const b = @as(u64, @intCast(self.stack.pop().?.i64));
-                    try self.stack.append(Value{ .i32 = @intCast(@as(u1, @bitCast(b < a))) });
+                    try self.stack.append(Value{ .i64 = @intCast(@as(u1, @bitCast(b < a))) });
                 },
                 .i64_gt_s => @panic("UNIMPLEMENTED"),
                 .i64_gt_u => @panic("UNIMPLEMENTED"),
@@ -531,7 +531,7 @@ pub const Runtime = struct {
                 .i64_shl => {
                     const a = self.stack.pop().?.i64;
                     const b = self.stack.pop().?.i64;
-                    try self.stack.append(.{ .i64 = (b << @as(u6, @intCast(a))) });
+                    try self.stack.append(.{ .i64 = @intCast(b << @as(u6, @intCast(a))) });
                 },
                 .i64_shr_s => @panic("UNIMPLEMENTED"),
                 .i64_shr_u => {
@@ -656,6 +656,7 @@ pub const Runtime = struct {
         }
         switch (f.typ) {
             .internal => {
+                std.debug.print("Calling {d}\n", .{function});
                 const ir: IR = f.typ.internal.ir;
                 const function_type = f.func_type;
                 var frame = CallFrame{
diff --git a/src/sideros.zig b/src/sideros.zig
index 5c22c70..54603c1 100644
--- a/src/sideros.zig
+++ b/src/sideros.zig
@@ -26,8 +26,8 @@ fn init_mods() void {
     var global_runtime = mods.GlobalRuntime.init(allocator);
     defer global_runtime.deinit();
 
-    const file = std.fs.cwd().openFile("assets/mods/core.wasm", .{}) catch @panic("Couldn't open assets/mods/core.wasm");
-    // const file = std.fs.cwd().openFile("./test.wasm", .{}) catch @panic("Couldn't open test.wasm");
+    // const file = std.fs.cwd().openFile("assets/mods/core.wasm", .{}) catch @panic("Couldn't open assets/mods/core.wasm");
+    const file = std.fs.cwd().openFile("./test.wasm", .{}) catch @panic("Couldn't open test.wasm");
     const all = file.readToEndAlloc(allocator, 1_000_000) catch @panic("Unable to read the file"); // 1 MB
     defer allocator.free(all);
     var parser = mods.Parser.init(allocator, all) catch @panic("Failed to init parser");