diff options
Diffstat (limited to 'py/bc.h')
| -rw-r--r-- | py/bc.h | 74 |
1 files changed, 68 insertions, 6 deletions
@@ -32,12 +32,15 @@ // bytecode layout: // -// n_state : var uint -// n_exc_stack : var uint -// scope_flags : byte -// n_pos_args : byte number of arguments this function takes -// n_kwonly_args : byte number of keyword-only arguments this function takes -// n_def_pos_args : byte number of default positional arguments +// func signature : var uint +// contains six values interleaved bit-wise as: xSSSSEAA [xFSSKAED repeated] +// x = extension another byte follows +// S = n_state - 1 number of entries in Python value stack +// E = n_exc_stack number of entries in exception stack +// F = scope_flags four bits of flags, MP_SCOPE_FLAG_xxx +// A = n_pos_args number of arguments this function takes +// K = n_kwonly_args number of keyword-only arguments this function takes +// D = n_def_pos_args number of default positional arguments // // code_info_size : var uint | code_info_size counts bytes in this chunk // simple_name : var qstr | @@ -60,6 +63,65 @@ // const0 : obj // constN : obj +#define MP_BC_PRELUDE_SIG_ENCODE(S, E, scope, out_byte, out_env) \ +do { \ + /*// Get values to store in prelude */ \ + size_t F = scope->scope_flags & 0x0f; /* only need to store lower 4 flag bits */ \ + size_t A = scope->num_pos_args; \ + size_t K = scope->num_kwonly_args; \ + size_t D = scope->num_def_pos_args; \ + \ + /* Adjust S to shrink range, to compress better */ \ + S -= 1; \ + \ + /* Encode prelude */ \ + /* xSSSSEAA */ \ + uint8_t z = (S & 0xf) << 3 | (E & 1) << 2 | (A & 3); \ + S >>= 4; \ + E >>= 1; \ + A >>= 2; \ + while (S | E | F | A | K | D) { \ + out_byte(out_env, 0x80 | z); \ + /* xFSSKAED */ \ + z = (F & 1) << 6 | (S & 3) << 4 | (K & 1) << 3 \ + | (A & 1) << 2 | (E & 1) << 1 | (D & 1); \ + S >>= 2; \ + E >>= 1; \ + F >>= 1; \ + A >>= 1; \ + K >>= 1; \ + D >>= 1; \ + } \ + out_byte(out_env, z); \ +} while (0) + +#define MP_BC_PRELUDE_SIG_DECODE_INTO(ip, S, E, F, A, K, D) \ +do { \ + uint8_t z = *(ip)++; \ + /* xSSSSEAA */ \ + S = (z >> 3) & 0xf; \ + E = (z >> 2) & 0x1; \ + F = 0; \ + A = z & 0x3; \ + K = 0; \ + D = 0; \ + for (unsigned n = 0; z & 0x80; ++n) { \ + z = *(ip)++; \ + /* xFSSKAED */ \ + S |= (z & 0x30) << (2 * n); \ + E |= (z & 0x02) << n; \ + F |= ((z & 0x40) >> 6) << n; \ + A |= (z & 0x4) << n; \ + K |= ((z & 0x08) >> 3) << n; \ + D |= (z & 0x1) << n; \ + } \ + S += 1; \ +} while (0) + +#define MP_BC_PRELUDE_SIG_DECODE(ip) \ + size_t n_state, n_exc_stack, scope_flags, n_pos_args, n_kwonly_args, n_def_pos_args; \ + MP_BC_PRELUDE_SIG_DECODE_INTO(ip, n_state, n_exc_stack, scope_flags, n_pos_args, n_kwonly_args, n_def_pos_args) + // Sentinel value for mp_code_state_t.exc_sp_idx #define MP_CODE_STATE_EXC_SP_IDX_SENTINEL ((uint16_t)-1) |