factor/vm/cpu-x86.hpp

82 lines
2.1 KiB
C++

#include <assert.h>
namespace factor
{
#define FRAME_RETURN_ADDRESS(frame,vm) *(void **)(vm->frame_successor(frame) + 1)
inline static void flush_icache(cell start, cell len) {}
/* In the instruction sequence:
MOV EBX,...
JMP blah
the offset from the immediate operand to MOV to the instruction after
the jump is a cell for the immediate operand, 4 bytes for the JMP
destination, and one byte for the JMP opcode. */
static const fixnum xt_tail_pic_offset = sizeof(cell) + 4 + 1;
static const unsigned char call_opcode = 0xe8;
static const unsigned char jmp_opcode = 0xe9;
inline static unsigned char call_site_opcode(cell return_address)
{
return *(unsigned char *)(return_address - 5);
}
inline static void check_call_site(cell return_address)
{
#ifdef FACTOR_DEBUG
unsigned char opcode = call_site_opcode(return_address);
assert(opcode == call_opcode || opcode == jmp_opcode);
#endif
}
inline static void *get_call_target(cell return_address)
{
check_call_site(return_address);
return (void *)(*(int *)(return_address - 4) + return_address);
}
inline static void set_call_target(cell return_address, void *target)
{
check_call_site(return_address);
*(int *)(return_address - 4) = ((cell)target - return_address);
}
inline static bool tail_call_site_p(cell return_address)
{
return call_site_opcode(return_address) == jmp_opcode;
}
inline static unsigned int fpu_status(unsigned int status)
{
unsigned int r = 0;
if (status & 0x01)
r |= FP_TRAP_INVALID_OPERATION;
if (status & 0x04)
r |= FP_TRAP_ZERO_DIVIDE;
if (status & 0x08)
r |= FP_TRAP_OVERFLOW;
if (status & 0x10)
r |= FP_TRAP_UNDERFLOW;
if (status & 0x20)
r |= FP_TRAP_INEXACT;
return r;
}
/* Defined in assembly */
VM_ASM_API void c_to_factor(cell quot, void *vm);
VM_ASM_API void throw_impl(cell quot, stack_frame *rewind_to, void *vm);
VM_ASM_API void lazy_jit_compile(cell quot, void *vm);
VM_C_API void set_callstack(stack_frame *to,
stack_frame *from,
cell length,
void *(*memcpy)(void*,const void*, size_t));
}