Initial commit.

1 files changed, 272 insertions, 0 deletions

diff --git a/py/bc.c b/py/bc.c
new file mode 100644
index 0000000000..1edd911ab6
--- /dev/null
+++ b/py/bc.c
@@ -0,0 +1,272 @@
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+
+#include "misc.h"
+#include "machine.h"
+#include "runtime.h"
+#include "bc.h"
+
+#define DECODE_UINT do { unum = *ip++; if (unum > 127) { unum = ((unum & 0x3f) << 8) | (*ip++); } } while (0)
+#define DECODE_QSTR do { qstr = *ip++; if (qstr > 127) { qstr = ((qstr & 0x3f) << 8) | (*ip++); } } while (0)
+#define PUSH(val) *--sp = (val)
+#define POP() (*sp++)
+
+py_obj_t py_execute_byte_code(byte *code, uint len, py_obj_t *args, uint n_args) {
+    byte *ip = code;
+    py_obj_t stack[10];
+    py_obj_t *sp = &stack[10]; // stack grows down, sp points to top of stack
+    machine_uint_t unum;
+    machine_int_t snum;
+    qstr qstr;
+    py_obj_t obj1, obj2;
+    py_obj_t fast0 = NULL, fast1 = NULL, fast2 = NULL, fastn[4] = {NULL, NULL, NULL, NULL};
+
+    // init args
+    for (int i = 0; i < n_args; i++) {
+        if (i == 0) {
+            fast0 = args[0];
+        } else if (i == 1) {
+            fast1 = args[1];
+        } else if (i == 2) {
+            fast2 = args[2];
+        } else {
+            assert(i - 3 < 4);
+            fastn[i - 3] = args[i];
+        }
+    }
+
+    // execute byte code
+    for (;;) {
+        int op = *ip++;
+        switch (op) {
+            case PYBC_LOAD_CONST_FALSE:
+                PUSH(py_const_false);
+                break;
+
+            case PYBC_LOAD_CONST_NONE:
+                PUSH(py_const_none);
+                break;
+
+            case PYBC_LOAD_CONST_TRUE:
+                PUSH(py_const_true);
+                break;
+
+            case PYBC_LOAD_CONST_SMALL_INT:
+                snum = ip[0] | (ip[1] << 8);
+                if (snum & 0x8000) {
+                    snum |= ~0xffff;
+                }
+                ip += 2;
+                PUSH((py_obj_t)(snum << 1 | 1));
+                break;
+
+            case PYBC_LOAD_CONST_ID:
+                DECODE_QSTR;
+                PUSH(rt_load_const_str(qstr)); // TODO
+                break;
+
+            case PYBC_LOAD_CONST_STRING:
+                DECODE_QSTR;
+                PUSH(rt_load_const_str(qstr));
+                break;
+
+            case PYBC_LOAD_FAST_0:
+                PUSH(fast0);
+                break;
+
+            case PYBC_LOAD_FAST_1:
+                PUSH(fast1);
+                break;
+
+            case PYBC_LOAD_FAST_2:
+                PUSH(fast2);
+                break;
+
+            case PYBC_LOAD_FAST_N:
+                DECODE_UINT;
+                PUSH(fastn[unum - 3]);
+                break;
+
+            case PYBC_LOAD_NAME:
+                DECODE_QSTR;
+                PUSH(rt_load_name(qstr));
+                break;
+
+            case PYBC_LOAD_GLOBAL:
+                DECODE_QSTR;
+                PUSH(rt_load_global(qstr));
+                break;
+
+            case PYBC_LOAD_ATTR:
+                DECODE_QSTR;
+                *sp = rt_load_attr(*sp, qstr);
+                break;
+
+            case PYBC_LOAD_METHOD:
+                DECODE_QSTR;
+                sp -= 1;
+                rt_load_method(sp[1], qstr, sp);
+                break;
+
+            case PYBC_LOAD_BUILD_CLASS:
+                PUSH(rt_load_build_class());
+                break;
+
+            case PYBC_STORE_FAST_0:
+                fast0 = POP();
+                break;
+
+            case PYBC_STORE_FAST_1:
+                fast1 = POP();
+                break;
+
+            case PYBC_STORE_FAST_2:
+                fast2 = POP();
+                break;
+
+            case PYBC_STORE_FAST_N:
+                DECODE_UINT;
+                fastn[unum - 3] = POP();
+                break;
+
+            case PYBC_STORE_NAME:
+                DECODE_QSTR;
+                rt_store_name(qstr, POP());
+                break;
+
+            case PYBC_STORE_SUBSCR:
+                rt_store_subscr(sp[1], sp[0], sp[2]);
+                sp += 3;
+                break;
+
+            case PYBC_DUP_TOP:
+                obj1 = *sp;
+                PUSH(obj1);
+                break;
+
+            case PYBC_DUP_TOP_TWO:
+                sp -= 2;
+                sp[0] = sp[2];
+                sp[1] = sp[3];
+                break;
+
+            case PYBC_POP_TOP:
+                ++sp;
+                break;
+
+            case PYBC_ROT_THREE:
+                obj1 = sp[0];
+                sp[0] = sp[1];
+                sp[1] = sp[2];
+                sp[2] = obj1;
+                break;
+
+            case PYBC_JUMP:
+                DECODE_UINT;
+                ip = code + unum;
+                break;
+
+            case PYBC_POP_JUMP_IF_FALSE:
+                DECODE_UINT;
+                if (!rt_is_true(POP())) {
+                    ip = code + unum;
+                }
+                break;
+
+            case PYBC_SETUP_LOOP:
+                DECODE_UINT;
+                break;
+
+            case PYBC_POP_BLOCK:
+                break;
+
+            case PYBC_BINARY_OP:
+                unum = *ip++;
+                obj2 = POP();
+                obj1 = *sp;
+                *sp = rt_binary_op(unum, obj1, obj2);
+                break;
+
+            case PYBC_COMPARE_OP:
+                unum = *ip++;
+                obj2 = POP();
+                obj1 = *sp;
+                *sp = rt_compare_op(unum, obj1, obj2);
+                break;
+
+            case PYBC_BUILD_LIST:
+                DECODE_UINT;
+                obj1 = rt_build_list(unum, sp);
+                sp += unum - 1;
+                *sp = obj1;
+                break;
+
+            case PYBC_BUILD_MAP:
+                DECODE_UINT;
+                PUSH(rt_build_map(unum));
+                break;
+
+            case PYBC_STORE_MAP:
+                sp += 2;
+                rt_store_map(sp[0], sp[-2], sp[-1]);
+                break;
+
+            case PYBC_BUILD_SET:
+                DECODE_UINT;
+                obj1 = rt_build_set(unum, sp);
+                sp += unum - 1;
+                *sp = obj1;
+                break;
+
+            case PYBC_MAKE_FUNCTION:
+                DECODE_UINT;
+                PUSH(rt_make_function_from_id(unum));
+                break;
+
+            case PYBC_CALL_FUNCTION:
+                DECODE_UINT;
+                assert((unum & 0xff00) == 0); // n_keyword
+                // switch on n_positional
+                if ((unum & 0xff) == 0) {
+                    *sp = rt_call_function_0(*sp);
+                } else if ((unum & 0xff) == 1) {
+                    obj1 = *sp++; // the single argument
+                    *sp = rt_call_function_1(*sp, obj1);
+                } else if ((unum & 0xff) == 2) {
+                    obj2 = *sp++; // the second argument
+                    obj1 = *sp++; // the first argument
+                    *sp = rt_call_function_2(*sp, obj1, obj2);
+                } else {
+                    assert(0);
+                }
+                break;
+
+            case PYBC_CALL_METHOD:
+                DECODE_UINT;
+                assert((unum & 0xff00) == 0); // n_keyword
+                // switch on n_positional
+                if ((unum & 0xff) == 0) {
+                    obj1 = *sp++; // the self object (or NULL)
+                    *sp = rt_call_method_1(*sp, obj1);
+                } else if ((unum & 0xff) == 1) {
+                    obj2 = *sp++; // the first argument
+                    obj1 = *sp++; // the self object (or NULL)
+                    *sp = rt_call_function_2(*sp, obj1, obj2);
+                } else {
+                    assert(0);
+                }
+                break;
+
+            case PYBC_RETURN_VALUE:
+                return *sp;
+
+            default:
+                printf("code %p, offset %u, byte code 0x%02x not implemented\n", code, (uint)(ip - code), op);
+                assert(0);
+                return py_const_none;
+        }
+    }
+}