From 10615526cd7edc4c31523c41e736611320b1be4e Mon Sep 17 00:00:00 2001
From: Sean <skasun@gmail.com>
Date: Sat, 1 Jun 2024 04:29:59 -0700
Subject: [PATCH] supports 32bit labels on pea or ldx/lda pairs

---
 src/disasm.cc | 18 ++++++++++++++++++
 src/disasm.h  |  2 ++
 src/map.h     |  1 +
 3 files changed, 21 insertions(+)

diff --git a/src/disasm.cc b/src/disasm.cc
index d239fc6..f2073ea 100644
--- a/src/disasm.cc
+++ b/src/disasm.cc
@@ -74,6 +74,8 @@ std::shared_ptr<Inst> Disassembler::decodeInst(Handle f, Entry *entry) {
   uint32_t addr = entry->org;
   entry->flags &= IsFlags;  // clear changed flags
   uint32_t oldFlags = entry->flags;
+  inst->prevWord = entry->prevWord;
+  entry->prevWord = 0;
   switch (mode) {
     case IMP:
       inst->operType = Opr::None;
@@ -94,6 +96,7 @@ std::shared_ptr<Inst> Disassembler::decodeInst(Handle f, Entry *entry) {
       } else {
         inst->oper = f->r16();
         inst->operType = Opr::Imm16;
+        entry->prevWord = inst->oper;
       }
       break;
     case IMMX:
@@ -103,11 +106,13 @@ std::shared_ptr<Inst> Disassembler::decodeInst(Handle f, Entry *entry) {
       } else {
         inst->oper = f->r16();
         inst->operType = Opr::Imm16;
+        entry->prevWord = inst->oper;
       }
       break;
     case IMMS:
       inst->oper = f->r16();
       inst->operType = Opr::Imm16;
+      entry->prevWord = inst->oper;
       break;
     case ABS:
       inst->oper = f->r16();
@@ -267,6 +272,9 @@ std::string Disassembler::printInst(std::shared_ptr<Inst> inst) {
       break;
     case Opr::Imm16:
       args = "#" + hex(inst->oper, 4);
+      if (inst->prevWord && inst->oper) {
+        comment = checkDW(inst->oper, inst->prevWord);
+      }
       break;
     case Opr::Abs:
       args = hex(inst->oper, 6);
@@ -377,6 +385,16 @@ std::string Disassembler::lookup(uint16_t val) {
   return symbols[addr];
 }
 
+std::string Disassembler::checkDW(uint16_t cur, uint16_t prev) {
+  uint32_t addr = (cur << 16) + prev;
+  std::string ret = symbols[addr];
+  if (ret.empty()) {
+    addr = (prev << 16) + cur;
+    ret = symbols[addr];
+  }
+  return ret;
+}
+
 std::string Disassembler::hex(uint32_t val, int width) {
   static const char *digits = "0123456789abcdef";
   std::string ret;
diff --git a/src/disasm.h b/src/disasm.h
index d488d09..ca810d8 100644
--- a/src/disasm.h
+++ b/src/disasm.h
@@ -39,6 +39,7 @@ struct Inst {
   Opr operType;
   uint32_t oper;
   uint32_t flags;
+  uint16_t prevWord;
 };
 
 class Disassembler {
@@ -54,6 +55,7 @@ class Disassembler {
   bool valid(uint32_t address);
   std::string hex(uint32_t value, int width);
   std::string lookup(uint16_t value);
+  std::string checkDW(uint16_t val, uint16_t prev);
 
   std::map<uint32_t, std::string> symbols;
   std::shared_ptr<Fingerprints> fingerprints;
diff --git a/src/map.h b/src/map.h
index 40109ea..f5b36fb 100644
--- a/src/map.h
+++ b/src/map.h
@@ -27,6 +27,7 @@ class File {
 struct Entry {
   uint32_t org;
   uint32_t flags;
+  uint16_t prevWord;
 };
 
 class Map {