remove swapper in venom_to_assembly

and small rename

vyper/venom/basicblock.py

@@ -84,7 +84,7 @@
 
 COMMUTATIVE_INSTRUCTIONS = frozenset(["add", "mul", "smul", "or", "xor", "and", "eq"])
 
-FLIPPABLE_INSTRUCTIONS = ("gt", "lt", "sgt", "slt")
+COMPARATOR_INSTRUCTIONS = ("gt", "lt", "sgt", "slt")
 
 if TYPE_CHECKING:
     from vyper.venom.function import IRFunction
@@ -233,8 +233,8 @@ def is_commutative(self) -> bool:
         return self.opcode in COMMUTATIVE_INSTRUCTIONS
 
     @property
-    def is_flippable(self) -> bool:
-        return self.opcode in FLIPPABLE_INSTRUCTIONS
+    def is_comparator(self) -> bool:
+        return self.opcode in COMPARATOR_INSTRUCTIONS
 
     @property
     def is_bb_terminator(self) -> bool:
@@ -288,8 +288,8 @@ def get_outputs(self) -> list[IROperand]:
         """
         return [self.output] if self.output else []
 
-    def flip_operands(self):
-        assert self.is_flippable
+    def flip_comparison(self):
+        assert self.is_comparator
         if self.opcode in ("gt", "sgt"):
             self.opcode = self.opcode.replace("g", "l")
         else:

vyper/venom/passes/dft.py

@@ -72,11 +72,11 @@ def key(x):
         # heuristic: sort by size of child dependency graph
         children.sort(key=key)
 
-        if inst.is_commutative and children != list(self.ida[inst]):
+        if inst.is_commutative and children == list(self.ida[inst]):
             inst.operands.reverse()
 
-        if inst.is_flippable and children != list(self.ida[inst]):
-            inst.flip_operands()
+        if inst.is_comparator and children != list(self.ida[inst]):
+            inst.flip_comparison()
 
         for dep_inst in children:
             self._process_instruction_r(instructions, dep_inst)

vyper/venom/venom_to_assembly.py

@@ -434,13 +434,6 @@ def _generate_evm_for_instruction(
             # the same variable, however, before a jump that is not possible
             self._stack_reorder(assembly, stack, list(target_stack))
 
-        if inst.is_commutative:
-            cost_no_swap = self._stack_reorder([], stack, operands, dry_run=True)
-            operands[-1], operands[-2] = operands[-2], operands[-1]
-            cost_with_swap = self._stack_reorder([], stack, operands, dry_run=True)
-            if cost_with_swap > cost_no_swap:
-                operands[-1], operands[-2] = operands[-2], operands[-1]
-
         cost = self._stack_reorder([], stack, operands, dry_run=True)
         if DEBUG_SHOW_COST and cost:
             print("ENTER", inst, file=sys.stderr)