From 4b221b4da70783ba00fe82926f7c58c2d502763e Mon Sep 17 00:00:00 2001
From: _xeroxz <xerox@back.engineering>
Date: Fri, 6 Aug 2021 15:43:18 -0700
Subject: [PATCH] figured out how to call CreateGEP lol...

---
 include/vm_lifters.hpp |  5 ++++-
 include/vmp_rtn.hpp    |  5 +++--
 src/lifters/lconst.cpp |  3 ++-
 src/lifters/sreg.cpp   | 22 ++++++++++++++++++++++
 src/vmp_rtn.cpp        | 14 +++++++++++---
 5 files changed, 42 insertions(+), 7 deletions(-)

diff --git a/include/vm_lifters.hpp b/include/vm_lifters.hpp
index 1063bba..0e8827b 100644
--- a/include/vm_lifters.hpp
+++ b/include/vm_lifters.hpp
@@ -23,7 +23,10 @@ namespace vmp2::lifters
                              const vm::instrs::virt_instr_t &vinstr, llvm::IRBuilder<> *ir_builder ) >;
 
     extern lifter_callback_t lconstq;
-    inline std::map< vm::handler::mnemonic_t, lifter_callback_t * > lifters = { { vm::handler::LCONSTQ, &lconstq } };
+    extern lifter_callback_t sregq;
+
+    inline std::map< vm::handler::mnemonic_t, lifter_callback_t * > lifters = { { vm::handler::LCONSTQ, &lconstq },
+                                                                                { vm::handler::SREGQ, &sregq } };
 
     inline bool lift( vm::vmp_rtn_t *rtn, const vm::instrs::code_block_t &vm_code_block,
                       const vm::instrs::virt_instr_t &vinstr, llvm::IRBuilder<> *ir_builder )
diff --git a/include/vmp_rtn.hpp b/include/vmp_rtn.hpp
index fa88dc4..05993b6 100644
--- a/include/vmp_rtn.hpp
+++ b/include/vmp_rtn.hpp
@@ -26,11 +26,12 @@ namespace vm
         llvm::Function *lift( void );
         llvm::LLVMContext *llvm_ctx;
         llvm::Module *llvm_module;
-      private:
         std::uintptr_t rtn_begin;
         llvm::Function *llvm_fptr;
         std::shared_ptr< llvm::IRBuilder<> > ir_builder;
-        llvm::AllocaInst *virutal_registers, *virtual_stack;
+        llvm::AllocaInst *virtual_stack, *stack_ptr;
+
+        std::vector< llvm::AllocaInst * > virtual_registers;
         std::vector< llvm::BasicBlock * > llvm_code_blocks;
         std::vector< vm::instrs::code_block_t > vmp2_code_blocks;
     };
diff --git a/src/lifters/lconst.cpp b/src/lifters/lconst.cpp
index 55e6b4c..638960b 100644
--- a/src/lifters/lconst.cpp
+++ b/src/lifters/lconst.cpp
@@ -3,7 +3,8 @@
 namespace vmp2::lifters
 {
     lifter_callback_t lconstq = [ & ]( vm::vmp_rtn_t *rtn, const vm::instrs::code_block_t &vm_code_block,
-                                       const vm::instrs::virt_instr_t &vinstr, llvm::IRBuilder<> *ir_builder ) {
+                                const vm::instrs::virt_instr_t &vinstr, llvm::IRBuilder<> *ir_builder ) {
         auto push_val = llvm::ConstantInt::get( llvm::IntegerType::getInt64Ty( *rtn->llvm_ctx ), vinstr.operand.imm.u );
+
     };
 }
\ No newline at end of file
diff --git a/src/lifters/sreg.cpp b/src/lifters/sreg.cpp
index e69de29..3b899b9 100644
--- a/src/lifters/sreg.cpp
+++ b/src/lifters/sreg.cpp
@@ -0,0 +1,22 @@
+#include <vm_lifters.hpp>
+
+namespace vmp2::lifters
+{
+    // %t1 = %stack[%sp]
+    // add %sp, 8
+    // %vregX = %1
+    lifter_callback_t sregq = [ & ]( vm::vmp_rtn_t *rtn, const vm::instrs::code_block_t &vm_code_block,
+                                     const vm::instrs::virt_instr_t &vinstr, llvm::IRBuilder<> *ir_builder ) {
+        auto old_sp =
+            ir_builder->CreateLoad( llvm::IntegerType::get( *rtn->llvm_ctx, 64 ), rtn->stack_ptr, false, "old_sp" );
+
+        auto new_sp = ir_builder->CreateSub(
+            old_sp, llvm::ConstantInt::get( llvm::IntegerType::get( *rtn->llvm_ctx, 64 ), 8 ), "new_sp" );
+
+        ir_builder->CreateStore( new_sp, rtn->stack_ptr );
+
+        auto top_stack =
+            ir_builder->CreateGEP( llvm::ArrayType::get( llvm::IntegerType::get( *rtn->llvm_ctx, 8 ), 1024 ),
+                                   rtn->virtual_stack, new_sp, "top_stack" );
+    };
+} // namespace vmp2::lifters
\ No newline at end of file
diff --git a/src/vmp_rtn.cpp b/src/vmp_rtn.cpp
index ee8f895..3760363 100644
--- a/src/vmp_rtn.cpp
+++ b/src/vmp_rtn.cpp
@@ -30,13 +30,21 @@ namespace vm
         ir_builder = std::make_shared< llvm::IRBuilder<> >( *llvm_ctx );
         ir_builder->SetInsertPoint( llvm_code_blocks[ 0 ] );
 
-        // allocate virtual register space...
-        virutal_registers = ir_builder->CreateAlloca(
-            llvm::ArrayType::get( llvm::IntegerType::get( *llvm_ctx, 64 ), 24 ), nullptr, "vregs" );
+        for ( auto idx = 0u; idx < 24; ++idx )
+            // allocate virtual register space...
+            virtual_registers.push_back(
+                ir_builder->CreateAlloca( llvm::IntegerType::get( *llvm_ctx, 64 ), nullptr,
+                                          ( std::string( "vreg" ) + std::to_string( idx ) ).c_str() ) );
 
         // allocate stack space...
         virtual_stack = ir_builder->CreateAlloca( llvm::ArrayType::get( llvm::IntegerType::get( *llvm_ctx, 8 ), 1024 ),
                                                   nullptr, "stack" );
+
+        // allocate stack pointer...
+        stack_ptr = ir_builder->CreateAlloca( llvm::IntegerType::get( *llvm_ctx, 64 ), nullptr, "sp" );
+
+        ir_builder->CreateStore( llvm::ConstantInt::get( llvm::IntegerType::getInt64Ty( *llvm_ctx ), 1024 ),
+                                 stack_ptr );
     }
 
     llvm::Function *vmp_rtn_t::lift( void )