gplib/include/gp/vfs/platforms/gcc-x86_64.hpp

#pragma once

#include "gp/buffer.hpp"

#include <cstdint>

#define no_inline_decl(a) a __attribute__((noinline))

namespace gp{
	namespace specifics {
		struct platform_data {
			platform_data() = default;
			
			platform_data(gp::buffer<char> stack_str)
			: stack_ptr((stack_str.end()-16).data)
			, base_ptr(stack_ptr)
			{}

			uint64_t rbx, r12, r13, r14, r15;

			void* stack_ptr;
			void* base_ptr;

			void pull() __attribute__((always_inline))
			{
				__asm__ __volatile__(
					"movq %%rsp, %0\n"
					"movq %%rbp, %1\n" 
					"movq %%rbx, %2\n" 
					"movq %%r12, %3\n" 
					"movq %%r13, %4\n" 
					"movq %%r14, %5\n" 
					"movq %%r15, %6\n" 
					: "=m"(stack_ptr)
					, "=m"(base_ptr)
					, "=m"(rbx)
					, "=m"(r12)
					, "=m"(r13)
					, "=m"(r14)
					, "=m"(r15)
				);
			}

			void* push(void* location)  __attribute__((always_inline))
			{
				volatile void* volatile tmp = static_cast<char*>(stack_ptr) - sizeof(void*);
				*static_cast<volatile void* volatile * volatile>(tmp) = location;
				__asm__ __volatile__(
					"movq %1, %%rsp\n"
					"movq %2, %%rbp\n"
					"movq %3, %%rbx\n"
					"movq %4, %%r12\n"
					"movq %5, %%r13\n"
					"movq %6, %%r14\n"
					"movq %7, %%r15\n"
					"popq %0\n"
					: "+r"(location)
					: "m"(tmp)
					, "m"(base_ptr)
					, "m"(rbx)
					, "m"(r12)
					, "m"(r13)
					, "m"(r14)
					, "m"(r15)
					: "memory"
				);
				return location;
			}
		};
	}
}