GH-98831: Modernize a ton of simpler instructions (#100545)

* load_const and load_fast aren't families for now
* Don't decref unmoved names
* Modernize GET_ANEXT
* Modernize GET_AWAITABLE
* Modernize ASYNC_GEN_WRAP
* Modernize YIELD_VALUE
* Modernize POP_EXCEPT (in more than one way)
* Modernize PREP_RERAISE_STAR
* Modernize LOAD_ASSERTION_ERROR
* Modernize LOAD_BUILD_CLASS
* Modernize STORE_NAME
* Modernize LOAD_NAME
* Modernize LOAD_CLASSDEREF
* Modernize LOAD_DEREF
* Modernize STORE_DEREF
* Modernize COPY_FREE_VARS (mark it as done)
* Modernize LIST_TO_TUPLE
* Modernize LIST_EXTEND
* Modernize SET_UPDATE
* Modernize SETUP_ANNOTATIONS
* Modernize DICT_UPDATE
* Modernize DICT_MERGE
* Modernize MAP_ADD
* Modernize IS_OP
* Modernize CONTAINS_OP
* Modernize CHECK_EXC_MATCH
* Modernize IMPORT_NAME
* Modernize IMPORT_STAR
* Modernize IMPORT_FROM
* Modernize JUMP_FORWARD (mark it as done)
* Modernize JUMP_BACKWARD (mark it as done)

1 files changed, 12 insertions, 7 deletions

diff --git a/Tools/cases_generator/generate_cases.py b/Tools/cases_generator/generate_cases.py
index 85a7c60..5eed74c 100644
--- a/Tools/cases_generator/generate_cases.py
+++ b/Tools/cases_generator/generate_cases.py
@@ -125,6 +125,7 @@ class Instruction:
     # Set later
     family: parser.Family | None = None
     predicted: bool = False
+    unmoved_names: frozenset[str] = frozenset()
 
     def __init__(self, inst: parser.InstDef):
         self.inst = inst
@@ -141,6 +142,13 @@ class Instruction:
             effect for effect in inst.inputs if isinstance(effect, StackEffect)
         ]
         self.output_effects = inst.outputs  # For consistency/completeness
+        unmoved_names: set[str] = set()
+        for ieffect, oeffect in zip(self.input_effects, self.output_effects):
+            if ieffect.name == oeffect.name:
+                unmoved_names.add(ieffect.name)
+            else:
+                break
+        self.unmoved_names = frozenset(unmoved_names)
 
     def write(self, out: Formatter) -> None:
         """Write one instruction, sans prologue and epilogue."""
@@ -175,12 +183,8 @@ class Instruction:
         out.stack_adjust(diff)
 
         # Write output stack effect assignments
-        unmoved_names: set[str] = set()
-        for ieffect, oeffect in zip(self.input_effects, self.output_effects):
-            if ieffect.name == oeffect.name:
-                unmoved_names.add(ieffect.name)
         for i, oeffect in enumerate(reversed(self.output_effects), 1):
-            if oeffect.name not in unmoved_names:
+            if oeffect.name not in self.unmoved_names:
                 dst = StackEffect(f"PEEK({i})", "")
                 out.assign(dst, oeffect)
 
@@ -235,7 +239,8 @@ class Instruction:
             elif m := re.match(r"(\s*)DECREF_INPUTS\(\);\s*$", line):
                 space = m.group(1)
                 for ieff in self.input_effects:
-                    out.write_raw(f"{extra}{space}Py_DECREF({ieff.name});\n")
+                    if ieff.name not in self.unmoved_names:
+                        out.write_raw(f"{extra}{space}Py_DECREF({ieff.name});\n")
             else:
                 out.write_raw(extra + line)
 
@@ -533,7 +538,7 @@ class Analyzer:
     ) -> tuple[list[StackEffect], int]:
         """Analyze a super-instruction or macro.
 
-        Print an error if there's a cache effect (which we don't support yet).
+        Ignore cache effects.
 
         Return the list of variable names and the initial stack pointer.
         """