Assembler bugfixes - tests run successfully now

5 files changed, 236 insertions, 45 deletions

diff --git a/asm/assembler.cpp b/asm/assembler.cpp
index b555125..4eb37f0 100644
--- a/asm/assembler.cpp
+++ b/asm/assembler.cpp
@@ -2,6 +2,14 @@
 
 using namespace std::string_literals;
 
+Asm::Args::Immediate32::Immediate32(const Asm::Args::Immediate64& imm64)
+{
+ if (imm64.value() < 0x100000000)
+  m_value = static_cast<uint32_t>(imm64.value());
+ else
+  throw std::runtime_error("Immediate32: Constructed from too big Immediate64");
+}
+
 namespace {
 
 std::unordered_map<std::string, FactoryFunction> ops;
diff --git a/asm/assembler.h b/asm/assembler.h
index ea23fbc..8cdaa31 100644
--- a/asm/assembler.h
+++ b/asm/assembler.h
@@ -28,18 +28,21 @@ public:
  {
  public:
   Immediate8(uint8_t value): m_value(value) {}
-  uint8_t value() {return m_value;}
+  uint8_t value() const {return m_value;}
   std::vector<uint8_t> getCode() {return {m_value};};
 
  private:
   uint8_t m_value;
  };
 
+ class Immediate64;
+
  class Immediate32
  {
  public:
   Immediate32(uint32_t value): m_value(value) {}
-  uint32_t value() { return m_value; }
+  Immediate32(const Immediate64&); ///< Convert from Immediate64 if data is small enough
+  uint32_t value() const { return m_value; }
   std::vector<uint8_t> getCode() {
    std::vector<uint8_t> result(size_t(4));
    *(reinterpret_cast<uint32_t*>(result.data())) = boost::endian::native_to_little(m_value);
@@ -54,7 +57,7 @@ public:
  {
  public:
   Immediate64(uint64_t value): m_value(value) {}
-  uint64_t value() { return m_value; }
+  uint64_t value() const { return m_value; }
   std::vector<uint8_t> getCode() {
    std::vector<uint8_t> result(size_t(8));
    *(reinterpret_cast<uint64_t*>(result.data())) = boost::endian::native_to_little(m_value);
@@ -69,7 +72,7 @@ public:
  {
  public:
   Register8(const std::string& name): m_name(name) {}
-  std::string name() { return m_name; }
+  std::string name() const { return m_name; }
 
  private:
   std::string m_name;
@@ -79,7 +82,7 @@ public:
  {
  public:
   Register32(const std::string& name): m_name(name) {}
-  std::string name() { return m_name; }
+  std::string name() const { return m_name; }
 
  private:
   std::string m_name;
@@ -89,7 +92,7 @@ public:
  {
  public:
   Register64(const std::string& name): m_name(name) {}
-  std::string name() { return m_name; }
+  std::string name() const { return m_name; }
 
  private:
   std::string m_name;
@@ -100,10 +103,10 @@ public:
  {
  public:
   Mem8Ptr64(const std::string& reg, int32_t offs = 0): m_reg(reg), m_offs(offs) {}
-  Mem8Ptr64(const std::string& reg, const std::string& reg2 = ""s, int32_t offs = 0): m_reg(reg), m_reg2(reg2), m_offs(offs) {}
-  std::string reg() { return m_reg; }
-  std::string reg2() { return m_reg2; }
-  int32_t offs() { return m_offs; }
+  Mem8Ptr64(const std::string& reg, const std::string& reg2, int32_t offs = 0): m_reg(reg), m_reg2(reg2), m_offs(offs) {}
+  std::string reg() const { return m_reg; }
+  std::string reg2() const { return m_reg2; }
+  int32_t offs() const { return m_offs; }
 
  private:
   std::string m_reg;
@@ -116,10 +119,10 @@ public:
  {
  public:
   Mem32Ptr64(const std::string& reg, int32_t offs = 0): m_reg(reg), m_offs(offs) {}
-  Mem32Ptr64(const std::string& reg, const std::string& reg2 = ""s, int32_t offs = 0): m_reg(reg), m_reg2(reg2), m_offs(offs) {}
-  std::string reg() { return m_reg; }
-  std::string reg2() { return m_reg2; }
-  int32_t offs() { return m_offs; }
+  Mem32Ptr64(const std::string& reg, const std::string& reg2, int32_t offs = 0): m_reg(reg), m_reg2(reg2), m_offs(offs) {}
+  std::string reg() const { return m_reg; }
+  std::string reg2() const { return m_reg2; }
+  int32_t offs() const { return m_offs; }
 
  private:
   std::string m_reg;
@@ -132,10 +135,10 @@ public:
  {
  public:
   Mem64Ptr64(const std::string& reg, int32_t offs = 0): m_reg(reg), m_offs(offs) {}
-  Mem64Ptr64(const std::string& reg, const std::string& reg2 = ""s, int32_t offs = 0): m_reg(reg), m_reg2(reg2), m_offs(offs) {}
-  std::string reg() { return m_reg; }
-  std::string reg2() { return m_reg2; }
-  int32_t offs() { return m_offs; }
+  Mem64Ptr64(const std::string& reg, const std::string& reg2, int32_t offs = 0): m_reg(reg), m_reg2(reg2), m_offs(offs) {}
+  std::string reg() const { return m_reg; }
+  std::string reg2() const { return m_reg2; }
+  int32_t offs() const { return m_offs; }
 
  private:
   std::string m_reg;
@@ -147,7 +150,7 @@ public:
  {
  public:
   Label(const std::string& name): m_name(name) {}
-  std::string name() { return m_name; }
+  std::string name() const { return m_name; }
 
  private:
   std::string m_name;
diff --git a/asm/intel64/add.cpp b/asm/intel64/add.cpp
index 957c27f..07b14a1 100644
--- a/asm/intel64/add.cpp
+++ b/asm/intel64/add.cpp
@@ -28,12 +28,34 @@ Op_add::Op_add(const Asm::Args& args)
  { // add rax, imm32
   machine_code = REX("W") + std::vector<uint8_t>{ 0x05 } + std::any_cast<Asm::Args::Immediate32>(args[1]).getCode();
 
+ } else if (args[0].type() == typeid(Asm::Args::Register8) && args[1].type() == typeid(Asm::Args::Register8)) { // add reg8, reg8
+  machine_code = std::vector<uint8_t>{ 0x00 } + ModRM(std::any_cast<Asm::Args::Register8>(args[1]).name(), std::any_cast<Asm::Args::Register8>(args[0]).name());
+
+ } else if (args[0].type() == typeid(Asm::Args::Register32) && args[1].type() == typeid(Asm::Args::Register32)) { // add reg32, reg32
+  machine_code = std::vector<uint8_t>{ 0x01 } + ModRM(std::any_cast<Asm::Args::Register32>(args[1]).name(), std::any_cast<Asm::Args::Register32>(args[0]).name());
+
+ } else if (args[0].type() == typeid(Asm::Args::Register64) && args[1].type() == typeid(Asm::Args::Register64)) { // add reg64, reg64
+  machine_code = REX("W") + std::vector<uint8_t>{ 0x01 } + ModRM(std::any_cast<Asm::Args::Register64>(args[1]).name(), std::any_cast<Asm::Args::Register64>(args[0]).name());
+
  } else if (args[0].type() == typeid(Asm::Args::Register32) && args[1].type() == typeid(Asm::Args::Mem32Ptr64)) { // add reg32, [reg64]
   machine_code = std::vector<uint8_t>{ 0x03 } + ModRM(std::any_cast<Asm::Args::Register32>(args[0]).name(), std::any_cast<Asm::Args::Mem32Ptr64>(args[1]).reg());
 
  } else if (args[0].type() == typeid(Asm::Args::Register64) && args[1].type() == typeid(Asm::Args::Mem64Ptr64)) { // add reg64, [reg64]
   machine_code = REX("W") + std::vector<uint8_t>{ 0x03 } + ModRM(std::any_cast<Asm::Args::Register64>(args[0]).name(), std::any_cast<Asm::Args::Mem64Ptr64>(args[1]).reg());
 
+ } else if (args[0].type() == typeid(Asm::Args::Mem8Ptr64) && args[1].type() == typeid(Asm::Args::Immediate8)) { // add [reg64], imm8
+  machine_code = std::vector<uint8_t>{ 0x80 } + ModRM("/0", std::any_cast<Asm::Args::Mem8Ptr64>(args[0]).reg()) + std::any_cast<Asm::Args::Immediate8>(args[1]).getCode();
+
+ } else if (args[0].type() == typeid(Asm::Args::Mem32Ptr64) && args[1].type() == typeid(Asm::Args::Immediate32)) { // add [reg64], imm32
+  machine_code = std::vector<uint8_t>{ 0x81 } + ModRM("/0", std::any_cast<Asm::Args::Mem32Ptr64>(args[0]).reg()) + std::any_cast<Asm::Args::Immediate32>(args[1]).getCode();
+
+ } else if (args[0].type() == typeid(Asm::Args::Mem64Ptr64) && args[1].type() == typeid(Asm::Args::Immediate32)) { // add qword ptr [reg64], imm32 (sign-extended)
+  machine_code = REX("W") + std::vector<uint8_t>{ 0x81 } + ModRM("/0", std::any_cast<Asm::Args::Mem64Ptr64>(args[0]).reg()) + std::any_cast<Asm::Args::Immediate32>(args[1]).getCode();
+
+ } else if (args[0].type() == typeid(Asm::Args::Mem64Ptr64) && args[1].type() == typeid(Asm::Args::Immediate64)) { // add qword ptr [reg64], imm32 (sign-extended) - reduce imm64 to imm32!
+  Asm::Args::Immediate32 imm32{std::any_cast<Asm::Args::Immediate64>(args[1])};
+  machine_code = REX("W") + std::vector<uint8_t>{ 0x81 } + ModRM("/0", std::any_cast<Asm::Args::Mem64Ptr64>(args[0]).reg()) + imm32.getCode();
+
  } else {
   throw std::runtime_error("Unimplemented: add "s + args[0].type().name() + " "s + args[1].type().name());
  }
@@ -48,11 +70,32 @@ bool registered {
  registerOp(mangleName<Asm::Args::Register64, Asm::Args::Immediate32>("add"), [](const Asm::Args& args) -> std::shared_ptr<Op>{
                              return std::make_shared<Op_add>(args);
                              }) &&
+ registerOp(mangleName<Asm::Args::Register8, Asm::Args::Register8>("add"), [](const Asm::Args& args) -> std::shared_ptr<Op>{
+                             return std::make_shared<Op_add>(args);
+                             }) &&
+ registerOp(mangleName<Asm::Args::Register32, Asm::Args::Register32>("add"), [](const Asm::Args& args) -> std::shared_ptr<Op>{
+                             return std::make_shared<Op_add>(args);
+                             }) &&
+ registerOp(mangleName<Asm::Args::Register64, Asm::Args::Register64>("add"), [](const Asm::Args& args) -> std::shared_ptr<Op>{
+                             return std::make_shared<Op_add>(args);
+                             }) &&
  registerOp(mangleName<Asm::Args::Register32, Asm::Args::Mem32Ptr64>("add"), [](const Asm::Args& args) -> std::shared_ptr<Op>{
                              return std::make_shared<Op_add>(args);
                              }) &&
  registerOp(mangleName<Asm::Args::Register64, Asm::Args::Mem64Ptr64>("add"), [](const Asm::Args& args) -> std::shared_ptr<Op>{
                              return std::make_shared<Op_add>(args);
+                             }) &&
+ registerOp(mangleName<Asm::Args::Mem8Ptr64, Asm::Args::Immediate8>("add"), [](const Asm::Args& args) -> std::shared_ptr<Op>{
+                             return std::make_shared<Op_add>(args);
+                             }) &&
+ registerOp(mangleName<Asm::Args::Mem32Ptr64, Asm::Args::Immediate32>("add"), [](const Asm::Args& args) -> std::shared_ptr<Op>{
+                             return std::make_shared<Op_add>(args);
+                             }) &&
+ registerOp(mangleName<Asm::Args::Mem64Ptr64, Asm::Args::Immediate32>("add"), [](const Asm::Args& args) -> std::shared_ptr<Op>{
+                             return std::make_shared<Op_add>(args);
+                             }) &&
+ registerOp(mangleName<Asm::Args::Mem64Ptr64, Asm::Args::Immediate64>("add"), [](const Asm::Args& args) -> std::shared_ptr<Op>{ // automatically converted to 32-bit (sign extended) if small enough. Intel doesn't support ADD ..., imm64
+                             return std::make_shared<Op_add>(args);
                              })
 };
 
diff --git a/asm/intel64/encode.cpp b/asm/intel64/encode.cpp
index 51ca7a0..1b35d89 100644
--- a/asm/intel64/encode.cpp
+++ b/asm/intel64/encode.cpp
@@ -14,7 +14,7 @@ namespace {
 std::shared_ptr<Op> makeLoadValue(const FlowGraph::Data& data, const FlowGraph::Graph& graph)
 {
  if (data.type() != FlowGraph::DataType::Int) {
-  std::runtime_error("Bad type for operand: "s + std::to_string(int(data.type())));
+  throw std::runtime_error("Bad type for operand: "s + std::to_string(int(data.type())));
  }
 
  if (!data.storage())
@@ -41,7 +41,7 @@ std::shared_ptr<Op> makeLoadValue(const FlowGraph::Data& data, const FlowGraph::
 std::shared_ptr<Op> makeStoreValue(const FlowGraph::Data& data, const FlowGraph::Graph& graph)
 {
  if (data.type() != FlowGraph::DataType::Int) {
-  std::runtime_error("Bad type for operand: "s + std::to_string(int(data.type())));
+  throw std::runtime_error("Bad type for operand: "s + std::to_string(int(data.type())));
  }
 
  if (!data.storage())
@@ -60,7 +60,7 @@ std::shared_ptr<Op> makeStoreValue(const FlowGraph::Data& data, const FlowGraph:
 std::shared_ptr<Op> makeAddValue(const FlowGraph::Data& data, const FlowGraph::Graph& graph)
 {
  if (data.type() != FlowGraph::DataType::Int) {
-  std::runtime_error("Bad type for operand: "s + std::to_string(int(data.type())));
+  throw std::runtime_error("Bad type for operand: "s + std::to_string(int(data.type())));
  }
 
  if (!data.storage())
@@ -87,7 +87,7 @@ std::shared_ptr<Op> makeAddValue(const FlowGraph::Data& data, const FlowGraph::G
 std::vector<std::shared_ptr<Chunk>> makeMulValue(const FlowGraph::Data& data, const FlowGraph::Graph& graph)
 {
  if (data.type() != FlowGraph::DataType::Int) {
-  std::runtime_error("Bad type for operand: "s + std::to_string(int(data.type())));
+  throw std::runtime_error("Bad type for operand: "s + std::to_string(int(data.type())));
  }
 
  if (!data.storage())
diff --git a/asm/parse.cpp b/asm/parse.cpp
index e62f585..8f6f831 100644
--- a/asm/parse.cpp
+++ b/asm/parse.cpp
@@ -5,6 +5,7 @@
 #include <boost/algorithm/string.hpp>
 
 #include <exception>
+#include <functional>
 #include <regex>
 #include <unordered_set>
 
@@ -43,11 +44,13 @@ namespace {
   }
  }
 
+ std::string reg_re{"[[:alpha:]][[:alnum:]]*"};
+
  // parse optional label
  bool parseLabel(const std::string& asm_code, size_t& pos, std::string& result) {
   parseWhitespace(asm_code, pos);
   
-  std::regex re_label("([[:alpha:]]([[:alnum:]])+):", std::regex_constants::ECMAScript);
+  std::regex re_label("("s + reg_re + "):"s, std::regex_constants::ECMAScript);
 
   std::smatch match;
   if (std::regex_search(asm_code.cbegin() + pos, asm_code.cend(), match, re_label, std::regex_constants::match_continuous)) {
@@ -64,7 +67,7 @@ namespace {
  bool parseMnemonic(const std::string& asm_code, size_t& pos, std::string& result) {
   parseWhitespace(asm_code, pos);
   
-  std::regex re_mnemonic("[[:alpha:]]([[:alnum:]])+", std::regex_constants::ECMAScript);
+  std::regex re_mnemonic(reg_re, std::regex_constants::ECMAScript);
 
   std::smatch match;
   if (std::regex_search(asm_code.cbegin() + pos, asm_code.cend(), match, re_mnemonic, std::regex_constants::match_continuous)) {
@@ -77,10 +80,10 @@ namespace {
   return false;
  }
  
- bool parseRegister8(const std::string& asm_code, size_t& pos, std::any& result) {
+ bool parseRegister8(const std::string& asm_code, size_t& pos, std::any& result, size_t& size_hint) {
   parseWhitespace(asm_code, pos);
   
-  std::regex re_name("[[:alpha:]]+", std::regex_constants::ECMAScript);
+  std::regex re_name(reg_re, std::regex_constants::ECMAScript);
 
   std::smatch match;
   if (std::regex_search(asm_code.cbegin() + pos, asm_code.cend(), match, re_name, std::regex_constants::match_continuous)) {
@@ -88,6 +91,7 @@ namespace {
    if (reg8.contains(name)) {
     pos += name.size();
     result = Asm::Args::Register8(name);
+    size_hint = 8;
     return true;
    }
   }
@@ -95,10 +99,10 @@ namespace {
   return false;
  }
 
- bool parseRegister32(const std::string& asm_code, size_t& pos, std::any& result) {
+ bool parseRegister32(const std::string& asm_code, size_t& pos, std::any& result, size_t& size_hint) {
   parseWhitespace(asm_code, pos);
   
-  std::regex re_name("[[:alpha:]]+", std::regex_constants::ECMAScript);
+  std::regex re_name(reg_re, std::regex_constants::ECMAScript);
 
   std::smatch match;
   if (std::regex_search(asm_code.cbegin() + pos, asm_code.cend(), match, re_name, std::regex_constants::match_continuous)) {
@@ -106,6 +110,7 @@ namespace {
    if (reg32.contains(name)) {
     pos += name.size();
     result = Asm::Args::Register32(name);
+    size_hint = 32;
     return true;
    }
   }
@@ -113,10 +118,10 @@ namespace {
   return false;
  }
 
- bool parseRegister64(const std::string& asm_code, size_t& pos, std::any& result) {
+ bool parseRegister64(const std::string& asm_code, size_t& pos, std::any& result, size_t& size_hint) {
   parseWhitespace(asm_code, pos);
   
-  std::regex re_name("[[:alpha:]]+", std::regex_constants::ECMAScript);
+  std::regex re_name(reg_re, std::regex_constants::ECMAScript);
 
   std::smatch match;
   if (std::regex_search(asm_code.cbegin() + pos, asm_code.cend(), match, re_name, std::regex_constants::match_continuous)) {
@@ -124,6 +129,64 @@ namespace {
    if (reg64.contains(name)) {
     pos += name.size();
     result = Asm::Args::Register64(name);
+    size_hint = 64;
+    return true;
+   }
+  }
+
+  return false;
+ }
+
+ bool parseMem8Ptr64(const std::string& asm_code, size_t& pos, std::any& result, size_t& size_hint) {
+  parseWhitespace(asm_code, pos);
+  
+  std::regex re_name("byte ptr *\\[("s + reg_re + ")\\]"s, std::regex_constants::ECMAScript);
+
+  std::smatch match;
+  if (std::regex_search(asm_code.cbegin() + pos, asm_code.cend(), match, re_name, std::regex_constants::match_continuous)) {
+   std::string name {boost::algorithm::to_lower_copy(match[1].str())};
+   if (reg64.contains(name)) {
+    pos += match[0].length();
+    result = Asm::Args::Mem8Ptr64{name};
+    size_hint = 8;
+    return true;
+   }
+  }
+
+  return false;
+ }
+
+ bool parseMem32Ptr64(const std::string& asm_code, size_t& pos, std::any& result, size_t& size_hint) {
+  parseWhitespace(asm_code, pos);
+  
+  std::regex re_name("(dword ptr *)?\\[("s + reg_re + ")\\]"s, std::regex_constants::ECMAScript);
+
+  std::smatch match;
+  if (std::regex_search(asm_code.cbegin() + pos, asm_code.cend(), match, re_name, std::regex_constants::match_continuous)) {
+   std::string name {boost::algorithm::to_lower_copy(match[2].str())};
+   if (reg64.contains(name)) {
+    pos += match[0].length();
+    result = Asm::Args::Mem32Ptr64(name);
+    size_hint = 32;
+    return true;
+   }
+  }
+
+  return false;
+ }
+
+ bool parseMem64Ptr64(const std::string& asm_code, size_t& pos, std::any& result, size_t& size_hint) {
+  parseWhitespace(asm_code, pos);
+  
+  std::regex re_name("qword ptr *\\[("s + reg_re + ")\\]"s, std::regex_constants::ECMAScript);
+
+  std::smatch match;
+  if (std::regex_search(asm_code.cbegin() + pos, asm_code.cend(), match, re_name, std::regex_constants::match_continuous)) {
+   std::string name {boost::algorithm::to_lower_copy(match[1].str())};
+   if (reg64.contains(name)) {
+    pos += match[0].length();
+    result = Asm::Args::Mem64Ptr64(name);
+    size_hint = 64;
     return true;
    }
   }
@@ -131,7 +194,37 @@ namespace {
   return false;
  }
 
- bool parseImmediate32(const std::string& asm_code, size_t& pos, std::any& result) {
+ bool parseImmediate8(const std::string& asm_code, size_t& pos, std::any& result, size_t& size_hint) {
+  if (size_hint != 8)
+   return false;
+
+  parseWhitespace(asm_code, pos);
+  
+  std::regex re_name("[[:digit:]]+|0x[[:xdigit:]]+", std::regex_constants::ECMAScript);
+
+  std::smatch match;
+  if (std::regex_search(asm_code.cbegin() + pos, asm_code.cend(), match, re_name, std::regex_constants::match_continuous)) {
+   int32_t value{};
+   try {
+    value = stoll(match[0]);
+   } catch (...) {
+    throw std::runtime_error("Assembler parse error: Bad immediate: "s + match[0].str());
+   }
+   if (value < -128 || value > 255)
+    throw std::runtime_error("Assembler parse error: Bad 8 bit immediate: "s + match[0].str());
+
+   pos += match[0].length();
+   result = Asm::Args::Immediate8(static_cast<uint8_t>(value));
+   return true;
+  }
+
+  return false;
+ }
+
+ bool parseImmediate32(const std::string& asm_code, size_t& pos, std::any& result, size_t& size_hint) {
+  if (size_hint != 32 && size_hint != 0)
+   return false;
+  
   parseWhitespace(asm_code, pos);
   
   std::regex re_name("[[:digit:]]+|0x[[:xdigit:]]+", std::regex_constants::ECMAScript);
@@ -152,18 +245,54 @@ namespace {
   return false;
  }
 
+ bool parseImmediate64(const std::string& asm_code, size_t& pos, std::any& result, size_t& size_hint) {
+  if (size_hint != 64)
+   return false;
+
+  parseWhitespace(asm_code, pos);
+  
+  std::regex re_name("[[:digit:]]+|0x[[:xdigit:]]+", std::regex_constants::ECMAScript);
+
+  std::smatch match;
+  if (std::regex_search(asm_code.cbegin() + pos, asm_code.cend(), match, re_name, std::regex_constants::match_continuous)) {
+   int64_t value{};
+   try {
+    value = stoll(match[0]);
+   } catch (...) {
+    throw std::runtime_error("Assembler parse error: Bad immediate: "s + match[0].str());
+   }
+
+   pos += match[0].length();
+   result = Asm::Args::Immediate64(static_cast<uint64_t>(value));
+   return true;
+  }
+
+  return false;
+ }
+
  // parse optional single operand
- bool parseOperand(const std::string& asm_code, size_t& pos, std::any& result) {
+ bool parseOperand(const std::string& asm_code, size_t& pos, std::any& result, size_t& size_hint) {
   parseWhitespace(asm_code, pos);
 
-  if (parseRegister8(asm_code, pos, result))
+  if (parseRegister8(asm_code, pos, result, size_hint))
+   return true;
+  if (parseRegister32(asm_code, pos, result, size_hint))
+   return true;
+  if (parseRegister64(asm_code, pos, result, size_hint))
    return true;
-  if (parseRegister32(asm_code, pos, result))
+  
+  if (parseMem8Ptr64(asm_code, pos, result, size_hint))
+   return true;
+  if (parseMem32Ptr64(asm_code, pos, result, size_hint))
    return true;
-  if (parseRegister64(asm_code, pos, result))
+  if (parseMem64Ptr64(asm_code, pos, result, size_hint))
    return true;
 
-  if (parseImmediate32(asm_code, pos, result))
+  if (parseImmediate8(asm_code, pos, result, size_hint))
+   return true;
+  if (parseImmediate32(asm_code, pos, result, size_hint))
+   return true;
+  if (parseImmediate64(asm_code, pos, result, size_hint))
    return true;
 
   return false;
@@ -172,12 +301,13 @@ namespace {
  // parse optional multiple operands, separated by commas
  void parseOperands(const std::string& asm_code, size_t& pos, Asm::Args& result) {
   std::any operand;
-  if (parseOperand(asm_code, pos, operand)) {
+  size_t size_hint{0}; // in bits, 0=no hint
+  if (parseOperand(asm_code, pos, operand, size_hint)) {
    result.push_back(operand);
    parseWhitespace(asm_code, pos);
    while (pos < asm_code.size() && asm_code[pos] == ',') {
     pos++;
-    if (parseOperand(asm_code, pos, operand)) {
+    if (parseOperand(asm_code, pos, operand, size_hint)) {
      result.push_back(operand);
     } else {
      throw std::runtime_error("Assembler error: expected operand after comma");
@@ -223,20 +353,27 @@ namespace {
   // all optional:
   // label: mnemonic operands... ;comment <eol>
 
-  std::string result_string;
-  if (parseLabel(asm_code, pos, result_string))
-   result.emplace_back(std::make_shared<Label>(result_string));
+  std::string label;
+  std::function<void()> label_fn {[](){}};
+  if (parseLabel(asm_code, pos, label))
+   label_fn = [&]() { result.emplace_back(std::make_shared<Label>(label)); }; // defer to successfully completed line
 
-  if (parseMnemonic(asm_code, pos, result_string)) {
-   Asm::Args args;
+  std::string mnemonic;
+  Asm::Args args;
+  std::function<void()> mnemonic_fn {[](){}};
+  if (parseMnemonic(asm_code, pos, mnemonic)) {
    parseOperands(asm_code, pos, args);
-   result.emplace_back(makeOp(result_string, args));
+   mnemonic_fn = [&]() { result.emplace_back(makeOp(mnemonic, args)); }; // defer to successfully completed line
   }
 
   parseComment(asm_code, pos);
 
   if (!parseEol(asm_code, pos))
    throw std::runtime_error("Assembler error at pos "s + std::to_string(pos));
+
+  // Append only if no error occured, to get the correct error
+  label_fn();
+  mnemonic_fn();
  }
 
 } // namespace