Bit shifting

examples/crc32.py

@@ -82,7 +82,7 @@ _CRC32_Table: u32[256] = [
 ]
 
 def _crc32_f(crc: u32, byt: u8) -> u32:
-    return (crc >> 8) ^ _CRC32_Table[(crc & 0xFF) ^ byt]
+    return (crc >> 8) ^ _CRC32_Table[(crc & 0xFF) ^ u32(byt)]
 
 @exported
 def crc32(data: bytes) -> u32:

phasm/compiler.py

@@ -77,8 +77,11 @@ OPERATOR_MAP = {
 
 U8_OPERATOR_MAP = {
     # Under the hood, this is an i32
-    # Implementing XOR, OR, AND is fine since the 3 remaining
+    # Implementing Right Shift XOR, OR, AND is fine since the 3 remaining
     # bytes stay zero after this operation
+    # Since it's unsigned an unsigned value, Logical or Arithmetic shift right
+    # are the same operation
+    '>>': 'shr_u',
     '^': 'xor',
     '|': 'or',
     '&': 'and',
@@ -89,6 +92,8 @@ U32_OPERATOR_MAP = {
     '>': 'gt_u',
     '<=': 'le_u',
     '>=': 'ge_u',
+    '<<': 'shl',
+    '>>': 'shr_u',
     '^': 'xor',
     '|': 'or',
     '&': 'and',
@@ -99,6 +104,8 @@ U64_OPERATOR_MAP = {
     '>': 'gt_u',
     '<=': 'le_u',
     '>=': 'ge_u',
+    '<<': 'shl',
+    '>>': 'shr_u',
     '^': 'xor',
     '|': 'or',
     '&': 'and',

phasm/parser.py

@@ -244,6 +244,10 @@ class OurVisitor:
                 operator = '-'
             elif isinstance(node.op, ast.Mult):
                 operator = '*'
+            elif isinstance(node.op, ast.LShift):
+                operator = '<<'
+            elif isinstance(node.op, ast.RShift):
+                operator = '>>'
             elif isinstance(node.op, ast.BitOr):
                 operator = '|'
             elif isinstance(node.op, ast.BitXor):
@@ -433,16 +437,14 @@ class OurVisitor:
             if func.returns.__class__ != func.posonlyargs[0][1].__class__:
                 _raise_static_error(node, f'Expected a foldable function, {func.name} returns a {codestyle.type_(func.returns)} but expects a {codestyle.type_(func.posonlyargs[0][1])}')
 
-            t_u8 = module.types['u8']
-
-            if t_u8.__class__ != func.posonlyargs[1][1].__class__:
+            if module.types['u8'].__class__ != func.posonlyargs[1][1].__class__:
                 _raise_static_error(node, 'Only folding over bytes (u8) is supported at this time')
 
             return Fold(
                 exp_type,
                 Fold.Direction.LEFT,
                 func,
-                self.visit_Module_FunctionDef_expr(module, function, our_locals, t_u8, node.args[1]),
+                self.visit_Module_FunctionDef_expr(module, function, our_locals, func.returns, node.args[1]),
                 self.visit_Module_FunctionDef_expr(module, function, our_locals, module.types['bytes'], node.args[2]),
             )
         else:
@@ -550,7 +552,7 @@ class OurVisitor:
                 _raise_static_error(node, 'Expected integer value')
 
             if node.value < 0 or node.value > 255:
-                _raise_static_error(node, 'Integer value out of range')
+                _raise_static_error(node, f'Integer value out of range; expected 0..255, actual {node.value}')
 
             return ConstantUInt8(exp_type, node.value)
 

tests/integration/test_simple.py

@@ -60,6 +60,34 @@ def testEntry() -> {type_}:
     assert 7 == result.returned_value
     assert TYPE_MAP[type_] == type(result.returned_value)
 
+@pytest.mark.integration_test
+@pytest.mark.parametrize('type_', ['u32', 'u64']) # FIXME: Support u8, requires an extra AND operation
+def test_logical_left_shift(type_):
+    code_py = f"""
+@exported
+def testEntry() -> {type_}:
+    return 10 << 3
+"""
+
+    result = Suite(code_py).run_code()
+
+    assert 80 == result.returned_value
+    assert TYPE_MAP[type_] == type(result.returned_value)
+
+@pytest.mark.integration_test
+@pytest.mark.parametrize('type_', ['u8', 'u32', 'u64'])
+def test_logical_right_shift(type_):
+    code_py = f"""
+@exported
+def testEntry() -> {type_}:
+    return 10 >> 3
+"""
+
+    result = Suite(code_py).run_code()
+
+    assert 1 == result.returned_value
+    assert TYPE_MAP[type_] == type(result.returned_value)
+
 @pytest.mark.integration_test
 @pytest.mark.parametrize('type_', ['u8', 'u32', 'u64'])
 def test_bitwise_or(type_):