add more tests

tests/unit/compiler/venom/test_literals_codesize.py

@@ -7,7 +7,7 @@
 from vyper.venom.passes import ReduceLiteralsCodesize
 
 
-@pytest.mark.parametrize("orig_value", [0xFF << 248, 2**256 - 1])
+@pytest.mark.parametrize("orig_value", [0xFFFF << 240, 2**256 - 1])
 def test_ff_inversion(orig_value):
     ctx = IRContext()
     fn = ctx.create_function("_global")
@@ -20,3 +20,58 @@ def test_ff_inversion(orig_value):
 
     assert bb.instructions[0].opcode == "not"
     assert evm_not(bb.instructions[0].operands[0].value) == orig_value
+
+
+should_not_invert = [1, 0xFE << 248 | (2**248 - 1)]  # 0xfeff...ff
+
+
+@pytest.mark.parametrize("orig_value", should_not_invert)
+def test_no_inversion(orig_value):
+    ctx = IRContext()
+    fn = ctx.create_function("_global")
+    bb = fn.get_basic_block()
+
+    bb.append_instruction("store", IRLiteral(orig_value))
+    bb.append_instruction("stop")
+    ac = IRAnalysesCache(fn)
+    ReduceLiteralsCodesize(ac, fn).run_pass()
+
+    assert bb.instructions[0].opcode == "store"
+    assert bb.instructions[0].operands[0].value == orig_value
+
+
+should_shl = [0x01_000000]  # saves 3 bytes
+
+
+@pytest.mark.parametrize("orig_value", should_shl)
+def test_shl(orig_value):
+    ctx = IRContext()
+    fn = ctx.create_function("_global")
+    bb = fn.get_basic_block()
+
+    bb.append_instruction("store", IRLiteral(orig_value))
+    bb.append_instruction("stop")
+    ac = IRAnalysesCache(fn)
+    ReduceLiteralsCodesize(ac, fn).run_pass()
+
+    assert bb.instructions[0].opcode == "shl"
+    op0, op1 = bb.instructions[0].operands
+    assert op0.value << op1.value == orig_value
+
+
+should_not_shl = [0x01_00]  # only saves 2 bytes
+
+
+@pytest.mark.parametrize("orig_value", should_not_shl)
+def test_no_shl(orig_value):
+    ctx = IRContext()
+    fn = ctx.create_function("_global")
+    bb = fn.get_basic_block()
+
+    bb.append_instruction("store", IRLiteral(orig_value))
+    bb.append_instruction("stop")
+    ac = IRAnalysesCache(fn)
+    ReduceLiteralsCodesize(ac, fn).run_pass()
+
+    assert bb.instructions[0].opcode == "store"
+    assert bb.instructions[0].operands[0].value == orig_value

vyper/venom/passes/literals_codesize.py

@@ -23,7 +23,7 @@ def _process_bb(self, bb):
             val = op.value % (2**256)
 
             # transform things like 0xffff...01 to (not 0xfe)
-            if len(hex(val)) // 2 - len(hex(evm_not(val))) // 2 > 0:
+            if len(hex(val)) // 2 - len(hex(evm_not(val))) // 2 > 1:  # not is 1 byte
                 inst.opcode = "not"
                 op.value = evm_not(val)
                 continue