bool compile(const Program &program, Translator &trans, Environment &env) {
jit_node_t *ref;
jit_node_t *fn = jit_note(NULL, 0);
jit_prolog();
const int stack_base_offset = jit_allocai(32 * sizeof(double));
int stack_top_idx = 0;
auto &&stackPush = [&](int reg) {
jit_stxi_d(stack_base_offset + stack_top_idx * sizeof(double), JIT_FP, reg);
++stack_top_idx;
};
auto &&stackPop = [&](int reg) {
--stack_top_idx;
jit_ldxi_d(reg, JIT_FP, stack_base_offset + stack_top_idx * sizeof(double));
return reg;
};
size_t pc = 0;
const size_t progsz = program.size();
while (pc < progsz) {
const Instruction &instr = program[pc];
switch (instr.op) {
case OP_NOP:
break;
case OP_PUSH:
stackPush(JIT_F0);
jit_movi_d(JIT_F0, instr.dval);
break;
case OP_ADD: {
const int reg = stackPop(JIT_F1);
jit_addr_d(JIT_F0, reg, JIT_F0);
}
break;
case OP_SUB: {
const int reg = stackPop(JIT_F1);
jit_subr_d(JIT_F0, reg, JIT_F0);
}
break;
case OP_MUL: {
const int reg = stackPop(JIT_F1);
jit_mulr_d(JIT_F0, reg, JIT_F0);
}
break;
case OP_DIV: {
const int reg = stackPop(JIT_F1);
jit_divr_d(JIT_F0, reg, JIT_F0);
}
break;
case OP_CALL: {
stackPush(JIT_F0);
const int sp = stack_top_idx - (instr.callop.nargs);
jit_addi(JIT_R0, JIT_FP, stack_base_offset + sp * sizeof(double));
jit_prepare();
jit_pushargi((jit_word_t)&env); // 1st arg: userdata
jit_pushargi(instr.callop.nargs); // 2nd arg: # of arguments
jit_pushargr(JIT_R0); // 3rd arg: pointer to args on stack
jit_pushargi((jit_word_t)&error_); // 4th arg: pointer to error message
auto &&cb = trans.lookup(instr.callop.fidx);
jit_finishi(reinterpret_cast<jit_pointer_t>(cb));
stack_top_idx -= instr.callop.nargs; // consume arguments on stack
jit_retval_d(JIT_F0);
jit_retval(JIT_R0);
ref = jit_bnei(JIT_R0, 0);
jit_reti_d(*reinterpret_cast<const double*>(&JIT_ERROR));
jit_patch(ref);
}
break;
}
++pc;
}
jit_retr_d(JIT_F0);
jit_epilog();
(void)jit_emit();
func_ = reinterpret_cast<JitFunction>(jit_address(fn));
return true;
}
pdfd
compile_rpn (char *expr)
{
pdfd fn;
int ofs, sp = 1;
fn = (pdfd) (jit_get_ip ().dptr);
jit_leaf (1);
ofs = jit_arg_d ();
jit_getarg_d (regs[0], ofs);
while (*expr)
{
char buf[32];
int n;
/* This scanner is much less advanced than the one in rpn.c. */
if (sscanf (expr, "%[0-9]%n", buf, &n))
{
double d = strtod (buf, NULL);
expr += n - 1;
jit_movi_d (regs[sp], d);
sp++;
}
else if (*expr == '+')
{
jit_addr_d (regs[sp - 2], regs[sp - 2], regs[sp - 1]);
sp--;
}
else if (*expr == '-')
{
jit_subr_d (regs[sp - 2], regs[sp - 2], regs[sp - 1]);
sp--;
}
else if (*expr == '*')
{
jit_mulr_d (regs[sp - 2], regs[sp - 2], regs[sp - 1]);
sp--;
}
else if (*expr == '/')
{
jit_divr_d (regs[sp - 2], regs[sp - 2], regs[sp - 1]);
sp--;
}
else
{
fprintf (stderr, "cannot compile: %s\n", expr);
abort ();
}
++expr;
}
jit_movr_d (JIT_FPRET, regs[0]);
jit_ret ();
jit_flush_code ((char *) fn, jit_get_ip ().ptr);
#ifdef LIGHTNING_DISASSEMBLE
disassemble (stderr, (char *) fn, jit_get_ip ().ptr);
#endif
return fn;
}
