factor/vm/cpu-ppc.hpp

namespace factor
{

#define FACTOR_CPU_STRING "ppc"
#define VM_ASM_API VM_C_API

register cell ds asm("r13");
register cell rs asm("r14");

/* In the instruction sequence:

   LOAD32 r3,...
   B blah

   the offset from the immediate operand to LOAD32 to the instruction after
   the branch is two instructions. */
static const fixnum xt_tail_pic_offset = 4 * 2;

inline static void check_call_site(cell return_address)
{
#ifdef FACTOR_DEBUG
	cell insn = *(cell *)return_address;
	/* Check that absolute bit is 0 */
	assert((insn & 0x2) == 0x0);
	/* Check that instruction is branch */
	assert((insn >> 26) == 0x12);
#endif
}

static const cell b_mask = 0x3fffffc;

inline static void *get_call_target(cell return_address)
{
	return_address -= sizeof(cell);
	check_call_site(return_address);

	cell insn = *(cell *)return_address;
	cell unsigned_addr = (insn & b_mask);
	fixnum signed_addr = (fixnum)(unsigned_addr << 6) >> 6;
	return (void *)(signed_addr + return_address);
}

inline static void set_call_target(cell return_address, void *target)
{
	return_address -= sizeof(cell);
	check_call_site(return_address);

	cell insn = *(cell *)return_address;

	fixnum relative_address = ((cell)target - return_address);
	insn = ((insn & ~b_mask) | (relative_address & b_mask));
	*(cell *)return_address = insn;

	/* Flush the cache line containing the call we just patched */
	__asm__ __volatile__ ("icbi 0, %0\n" "sync\n"::"r" (return_address):);
}

inline static bool tail_call_site_p(cell return_address)
{
	return_address -= sizeof(cell);
	cell insn = *(cell *)return_address;
	return (insn & 0x1) == 0;
}

inline static unsigned int fpu_status(unsigned int status)
{
        unsigned int r = 0;

        if (status & 0x20000000)
		r |= FP_TRAP_INVALID_OPERATION;
        if (status & 0x10000000)
		r |= FP_TRAP_OVERFLOW;
        if (status & 0x08000000)
		r |= FP_TRAP_UNDERFLOW;
        if (status & 0x04000000)
		r |= FP_TRAP_ZERO_DIVIDE;
        if (status & 0x02000000)
		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, void *vm);
VM_ASM_API void lazy_jit_compile(cell quot, void *vm);
VM_ASM_API void flush_icache(cell start, cell len);

VM_ASM_API void set_callstack(stack_frame *to,
			       stack_frame *from,
			       cell length,
			       void *(*memcpy)(void*,const void*, size_t));

}