From 541a2dffdcb02063f71d21af22aebbd293c9e49f Mon Sep 17 00:00:00 2001
From: Roland Reichwein <mail@reichwein.it>
Date: Fri, 27 Nov 2020 22:51:50 +0100
Subject: Added CMP

---
 asm/intel64/cmp.cpp | 114 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 114 insertions(+)
 create mode 100644 asm/intel64/cmp.cpp

(limited to 'asm/intel64/cmp.cpp')

diff --git a/asm/intel64/cmp.cpp b/asm/intel64/cmp.cpp
new file mode 100644
index 0000000..3a2a582
--- /dev/null
+++ b/asm/intel64/cmp.cpp
@@ -0,0 +1,114 @@
+#include "cmp.h"
+
+#include "codes.h"
+
+#include <asm/assembler.h>
+#include <asm/operators.h>
+
+using namespace std::string_literals;
+
+Op_cmp::Op_cmp(const Asm::Args& args)
+{
+ if (args[0].type() == typeid(Asm::Args::Register32) &&
+     std::any_cast<Asm::Args::Register32>(args[0]).name() == "eax" &&
+     args[1].type() == typeid(Asm::Args::Immediate32))
+ { // cmp eax, imm32 (before "cmp reg32, imm32"! It's shorter.)
+  machine_code = std::vector<uint8_t>{ 0x3D } + std::any_cast<Asm::Args::Immediate32>(args[1]).getCode();
+
+ } else if (args[0].type() == typeid(Asm::Args::Register32) &&
+     args[1].type() == typeid(Asm::Args::Immediate32))
+ { // cmp reg32, imm32
+  machine_code = std::vector<uint8_t>{ 0x81 } + ModRM("/7", std::any_cast<Asm::Args::Register32>(args[0]).name()) + std::any_cast<Asm::Args::Immediate32>(args[1]).getCode();
+
+ } else if (args[0].type() == typeid(Asm::Args::Register64) &&
+            std::any_cast<Asm::Args::Register64>(args[0]).name() == "rax"  &&
+            args[1].type() == typeid(Asm::Args::Immediate32))
+
+ { // cmp rax, imm32 (sign extended)
+  machine_code = REX("W") + std::vector<uint8_t>{ 0x3D } + 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)) { // cmp reg8, reg8
+  machine_code = std::vector<uint8_t>{ 0x38 } + 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::Register16) && args[1].type() == typeid(Asm::Args::Register16)) { // cmp reg16, reg16
+  machine_code = OpSizePrefix() + std::vector<uint8_t>{ 0x39 } + 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)) { // cmp reg32, reg32
+  machine_code = std::vector<uint8_t>{ 0x39 } + 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)) { // cmp reg64, reg64
+  machine_code = REX("W") + std::vector<uint8_t>{ 0x39 } + 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)) { // cmp reg32, [reg64]
+  Asm::Args::Mem32Ptr64 ptr{std::any_cast<Asm::Args::Mem32Ptr64>(args[1])};
+  machine_code = std::vector<uint8_t>{ 0x3B } + ModRM(std::any_cast<Asm::Args::Register32>(args[0]).name(), ptr.reg(), ptr.offs());
+
+ } else if (args[0].type() == typeid(Asm::Args::Register64) && args[1].type() == typeid(Asm::Args::Mem64Ptr64)) { // cmp reg64, [reg64]
+  Asm::Args::Mem64Ptr64 ptr{std::any_cast<Asm::Args::Mem64Ptr64>(args[1])};
+  machine_code = REX("W") + std::vector<uint8_t>{ 0x3B } + ModRM(std::any_cast<Asm::Args::Register64>(args[0]).name(), ptr.reg(), ptr.offs());
+
+ } else if (args[0].type() == typeid(Asm::Args::Mem8Ptr64) && args[1].type() == typeid(Asm::Args::Immediate8)) { // cmp [reg64], imm8
+  Asm::Args::Mem8Ptr64 ptr{std::any_cast<Asm::Args::Mem8Ptr64>(args[0])};
+  machine_code = std::vector<uint8_t>{ 0x80 } + ModRM("/7", ptr.reg(), ptr.offs()) + 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)) { // cmp [reg64], imm32
+  Asm::Args::Mem32Ptr64 ptr{std::any_cast<Asm::Args::Mem32Ptr64>(args[0])};
+  machine_code = std::vector<uint8_t>{ 0x81 } + ModRM("/7", ptr.reg(), ptr.offs()) + 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)) { // cmp qword ptr [reg64], imm32 (sign-extended)
+  Asm::Args::Mem64Ptr64 ptr{std::any_cast<Asm::Args::Mem64Ptr64>(args[0])};
+  machine_code = REX("W") + std::vector<uint8_t>{ 0x81 } + ModRM("/7", ptr.reg(), ptr.offs()) + 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)) { // cmp qword ptr [reg64], imm32 (sign-extended) - reduce imm64 to imm32!
+  Asm::Args::Mem64Ptr64 ptr{std::any_cast<Asm::Args::Mem64Ptr64>(args[0])};
+  Asm::Args::Immediate32 imm32{std::any_cast<Asm::Args::Immediate64>(args[1])};
+  machine_code = REX("W") + std::vector<uint8_t>{ 0x81 } + ModRM("/7", ptr.reg(), ptr.offs()) + imm32.getCode();
+
+ } else {
+  throw std::runtime_error("Unimplemented: cmp "s + args[0].type().name() + " "s + args[1].type().name());
+ }
+}
+
+namespace {
+
+bool registered {
+ registerOp(mangleName<Asm::Args::Register32, Asm::Args::Immediate32>("cmp"), [](const Asm::Args& args) -> std::shared_ptr<Op>{
+                             return std::make_shared<Op_cmp>(args);
+                             }) &&
+ registerOp(mangleName<Asm::Args::Register64, Asm::Args::Immediate32>("cmp"), [](const Asm::Args& args) -> std::shared_ptr<Op>{
+                             return std::make_shared<Op_cmp>(args);
+                             }) &&
+ registerOp(mangleName<Asm::Args::Register8, Asm::Args::Register8>("cmp"), [](const Asm::Args& args) -> std::shared_ptr<Op>{
+                             return std::make_shared<Op_cmp>(args);
+                             }) &&
+ registerOp(mangleName<Asm::Args::Register16, Asm::Args::Register16>("cmp"), [](const Asm::Args& args) -> std::shared_ptr<Op>{
+                             return std::make_shared<Op_cmp>(args);
+                             }) &&
+ registerOp(mangleName<Asm::Args::Register32, Asm::Args::Register32>("cmp"), [](const Asm::Args& args) -> std::shared_ptr<Op>{
+                             return std::make_shared<Op_cmp>(args);
+                             }) &&
+ registerOp(mangleName<Asm::Args::Register64, Asm::Args::Register64>("cmp"), [](const Asm::Args& args) -> std::shared_ptr<Op>{
+                             return std::make_shared<Op_cmp>(args);
+                             }) &&
+ registerOp(mangleName<Asm::Args::Register32, Asm::Args::Mem32Ptr64>("cmp"), [](const Asm::Args& args) -> std::shared_ptr<Op>{
+                             return std::make_shared<Op_cmp>(args);
+                             }) &&
+ registerOp(mangleName<Asm::Args::Register64, Asm::Args::Mem64Ptr64>("cmp"), [](const Asm::Args& args) -> std::shared_ptr<Op>{
+                             return std::make_shared<Op_cmp>(args);
+                             }) &&
+ registerOp(mangleName<Asm::Args::Mem8Ptr64, Asm::Args::Immediate8>("cmp"), [](const Asm::Args& args) -> std::shared_ptr<Op>{
+                             return std::make_shared<Op_cmp>(args);
+                             }) &&
+ registerOp(mangleName<Asm::Args::Mem32Ptr64, Asm::Args::Immediate32>("cmp"), [](const Asm::Args& args) -> std::shared_ptr<Op>{
+                             return std::make_shared<Op_cmp>(args);
+                             }) &&
+ registerOp(mangleName<Asm::Args::Mem64Ptr64, Asm::Args::Immediate32>("cmp"), [](const Asm::Args& args) -> std::shared_ptr<Op>{
+                             return std::make_shared<Op_cmp>(args);
+                             }) &&
+ registerOp(mangleName<Asm::Args::Mem64Ptr64, Asm::Args::Immediate64>("cmp"), [](const Asm::Args& args) -> std::shared_ptr<Op>{ // automatically converted to 32-bit (sign extended) if small enough. Intel doesn't support CMP ..., imm64
+                             return std::make_shared<Op_cmp>(args);
+                             })
+};
+
+}
+
-- 
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