mirror of
https://github.com/python/cpython.git
synced 2025-09-26 10:19:53 +00:00
GH-122155: Track local variables between pops and pushes in cases generator (GH-122286)
This commit is contained in:
Mark Shannon
GitHub
parent
46f5a4f9e1
commit
a9d56e38a0
13 changed files with 463 additions and 159 deletions
|
|
@ -38,6 +38,43 @@ def var_size(var: StackItem) -> str:
|
|||
else:
|
||||
return "1"
|
||||
|
||||
@dataclass
|
||||
class Local:
|
||||
|
||||
item: StackItem
|
||||
cached: bool
|
||||
in_memory: bool
|
||||
defined: bool
|
||||
|
||||
@staticmethod
|
||||
def unused(defn: StackItem) -> "Local":
|
||||
return Local(defn, False, defn.is_array(), False)
|
||||
|
||||
@staticmethod
|
||||
def local(defn: StackItem) -> "Local":
|
||||
array = defn.is_array()
|
||||
return Local(defn, not array, array, True)
|
||||
|
||||
@staticmethod
|
||||
def redefinition(var: StackItem, prev: "Local") -> "Local":
|
||||
assert var.is_array() == prev.is_array()
|
||||
return Local(var, prev.cached, prev.in_memory, True)
|
||||
|
||||
@property
|
||||
def size(self) -> str:
|
||||
return self.item.size
|
||||
|
||||
@property
|
||||
def name(self) -> str:
|
||||
return self.item.name
|
||||
|
||||
@property
|
||||
def condition(self) -> str | None:
|
||||
return self.item.condition
|
||||
|
||||
def is_array(self) -> bool:
|
||||
return self.item.is_array()
|
||||
|
||||
@dataclass
|
||||
class StackOffset:
|
||||
"The stack offset of the virtual base of the stack from the physical stack pointer"
|
||||
|
|
@ -66,7 +103,11 @@ class StackOffset:
|
|||
|
||||
def simplify(self) -> None:
|
||||
"Remove matching values from both the popped and pushed list"
|
||||
if not self.popped or not self.pushed:
|
||||
if not self.popped:
|
||||
self.pushed.sort()
|
||||
return
|
||||
if not self.pushed:
|
||||
self.popped.sort()
|
||||
return
|
||||
# Sort the list so the lexically largest element is last.
|
||||
popped = sorted(self.popped)
|
||||
|
|
@ -87,6 +128,8 @@ class StackOffset:
|
|||
popped.append(pop)
|
||||
self.popped.extend(popped)
|
||||
self.pushed.extend(pushed)
|
||||
self.pushed.sort()
|
||||
self.popped.sort()
|
||||
|
||||
def to_c(self) -> str:
|
||||
self.simplify()
|
||||
|
|
@ -125,10 +168,10 @@ class Stack:
|
|||
def __init__(self) -> None:
|
||||
self.top_offset = StackOffset.empty()
|
||||
self.base_offset = StackOffset.empty()
|
||||
self.variables: list[StackItem] = []
|
||||
self.variables: list[Local] = []
|
||||
self.defined: set[str] = set()
|
||||
|
||||
def pop(self, var: StackItem, extract_bits: bool = False) -> str:
|
||||
def pop(self, var: StackItem, extract_bits: bool = False) -> tuple[str, Local]:
|
||||
self.top_offset.pop(var)
|
||||
indirect = "&" if var.is_array() else ""
|
||||
if self.variables:
|
||||
|
|
@ -141,21 +184,32 @@ class Stack:
|
|||
if var.name in UNUSED:
|
||||
if popped.name not in UNUSED and popped.name in self.defined:
|
||||
raise StackError(f"Value is declared unused, but is already cached by prior operation")
|
||||
return ""
|
||||
if popped.name in UNUSED or popped.name not in self.defined:
|
||||
self.defined.add(var.name)
|
||||
return "", popped
|
||||
if not var.used:
|
||||
return "", popped
|
||||
self.defined.add(var.name)
|
||||
# Always define array variables as it is free, and their offset might have changed
|
||||
if var.is_array():
|
||||
return (
|
||||
f"{var.name} = {indirect}stack_pointer[{self.top_offset.to_c()}];\n"
|
||||
f"{var.name} = &stack_pointer[{self.top_offset.to_c()}];\n",
|
||||
Local.redefinition(var, popped)
|
||||
)
|
||||
if not popped.defined:
|
||||
return (
|
||||
f"{var.name} = stack_pointer[{self.top_offset.to_c()}];\n",
|
||||
Local.redefinition(var, popped)
|
||||
)
|
||||
else:
|
||||
self.defined.add(var.name)
|
||||
if popped.name == var.name:
|
||||
return ""
|
||||
return "", popped
|
||||
else:
|
||||
return f"{var.name} = {popped.name};\n"
|
||||
return (
|
||||
f"{var.name} = {popped.name};\n",
|
||||
Local.redefinition(var, popped)
|
||||
)
|
||||
self.base_offset.pop(var)
|
||||
if var.name in UNUSED or not var.used:
|
||||
return ""
|
||||
return "", Local.unused(var)
|
||||
self.defined.add(var.name)
|
||||
cast = f"({var.type})" if (not indirect and var.type) else ""
|
||||
bits = ".bits" if cast and not extract_bits else ""
|
||||
|
|
@ -164,61 +218,80 @@ class Stack:
|
|||
)
|
||||
if var.condition:
|
||||
if var.condition == "1":
|
||||
return f"{assign}\n"
|
||||
assign = f"{assign}\n"
|
||||
elif var.condition == "0":
|
||||
return ""
|
||||
return "", Local.unused(var)
|
||||
else:
|
||||
return f"if ({var.condition}) {{ {assign} }}\n"
|
||||
return f"{assign}\n"
|
||||
assign = f"if ({var.condition}) {{ {assign} }}\n"
|
||||
else:
|
||||
assign = f"{assign}\n"
|
||||
in_memory = var.is_array() or var.peek
|
||||
return assign, Local(var, not var.is_array(), in_memory, True)
|
||||
|
||||
def push(self, var: StackItem) -> str:
|
||||
def push(self, var: Local) -> str:
|
||||
self.variables.append(var)
|
||||
if var.is_array() and var.name not in self.defined and var.name not in UNUSED:
|
||||
if var.is_array() and not var.defined and var.item.used:
|
||||
assert var.in_memory
|
||||
assert not var.cached
|
||||
c_offset = self.top_offset.to_c()
|
||||
self.top_offset.push(var)
|
||||
self.top_offset.push(var.item)
|
||||
self.defined.add(var.name)
|
||||
var.defined = True
|
||||
return f"{var.name} = &stack_pointer[{c_offset}];\n"
|
||||
else:
|
||||
self.top_offset.push(var)
|
||||
if var.used:
|
||||
self.top_offset.push(var.item)
|
||||
if var.item.used:
|
||||
self.defined.add(var.name)
|
||||
return ""
|
||||
|
||||
def flush(self, out: CWriter, cast_type: str = "uintptr_t", extract_bits: bool = False) -> None:
|
||||
def define_output_arrays(self, outputs: list[StackItem]) -> str:
|
||||
res = []
|
||||
top_offset = self.top_offset.copy()
|
||||
for var in outputs:
|
||||
if var.is_array() and var.used and not var.peek:
|
||||
c_offset = top_offset.to_c()
|
||||
top_offset.push(var)
|
||||
res.append(f"{var.name} = &stack_pointer[{c_offset}];\n")
|
||||
else:
|
||||
top_offset.push(var)
|
||||
return "\n".join(res)
|
||||
|
||||
@staticmethod
|
||||
def _do_flush(out: CWriter, variables: list[Local], base_offset: StackOffset, top_offset: StackOffset,
|
||||
cast_type: str = "uintptr_t", extract_bits: bool = False) -> None:
|
||||
out.start_line()
|
||||
for var in self.variables:
|
||||
if not var.peek:
|
||||
cast = f"({cast_type})" if var.type else ""
|
||||
for var in variables:
|
||||
if var.cached and not var.in_memory and not var.item.peek and not var.name in UNUSED:
|
||||
cast = f"({cast_type})" if var.item.type else ""
|
||||
bits = ".bits" if cast and not extract_bits else ""
|
||||
if var.name not in UNUSED and not var.is_array():
|
||||
if var.condition:
|
||||
if var.condition == "0":
|
||||
continue
|
||||
elif var.condition != "1":
|
||||
out.emit(f"if ({var.condition}) ")
|
||||
out.emit(
|
||||
f"stack_pointer[{self.base_offset.to_c()}]{bits} = {cast}{var.name};\n"
|
||||
)
|
||||
self.base_offset.push(var)
|
||||
if self.base_offset.to_c() != self.top_offset.to_c():
|
||||
print("base", self.base_offset.to_c(), "top", self.top_offset.to_c())
|
||||
if var.condition == "0":
|
||||
continue
|
||||
if var.condition and var.condition != "1":
|
||||
out.emit(f"if ({var.condition}) ")
|
||||
out.emit(
|
||||
f"stack_pointer[{base_offset.to_c()}]{bits} = {cast}{var.name};\n"
|
||||
)
|
||||
base_offset.push(var.item)
|
||||
if base_offset.to_c() != top_offset.to_c():
|
||||
print("base", base_offset, "top", top_offset)
|
||||
assert False
|
||||
number = self.base_offset.to_c()
|
||||
number = base_offset.to_c()
|
||||
if number != "0":
|
||||
out.emit(f"stack_pointer += {number};\n")
|
||||
out.emit("assert(WITHIN_STACK_BOUNDS());\n")
|
||||
out.start_line()
|
||||
|
||||
def flush_locally(self, out: CWriter, cast_type: str = "uintptr_t", extract_bits: bool = False) -> None:
|
||||
self._do_flush(out, self.variables[:], self.base_offset.copy(), self.top_offset.copy(), cast_type, extract_bits)
|
||||
|
||||
def flush(self, out: CWriter, cast_type: str = "uintptr_t", extract_bits: bool = False) -> None:
|
||||
self._do_flush(out, self.variables, self.base_offset, self.top_offset, cast_type, extract_bits)
|
||||
self.variables = []
|
||||
self.base_offset.clear()
|
||||
self.top_offset.clear()
|
||||
out.start_line()
|
||||
|
||||
def peek_offset(self) -> str:
|
||||
peek = self.base_offset.copy()
|
||||
for var in self.variables:
|
||||
if not var.peek:
|
||||
break
|
||||
peek.push(var)
|
||||
return peek.to_c()
|
||||
return self.top_offset.to_c()
|
||||
|
||||
def as_comment(self) -> str:
|
||||
return f"/* Variables: {[v.name for v in self.variables]}. Base offset: {self.base_offset.to_c()}. Top offset: {self.top_offset.to_c()} */"
|
||||
|
|
@ -236,8 +309,15 @@ def get_stack_effect(inst: Instruction | PseudoInstruction) -> Stack:
|
|||
yield inst.stack
|
||||
|
||||
for s in stacks(inst):
|
||||
locals: dict[str, Local] = {}
|
||||
for var in reversed(s.inputs):
|
||||
stack.pop(var)
|
||||
_, local = stack.pop(var)
|
||||
if var.name != "unused":
|
||||
locals[local.name] = local
|
||||
for var in s.outputs:
|
||||
stack.push(var)
|
||||
if var.name in locals:
|
||||
local = locals[var.name]
|
||||
else:
|
||||
local = Local.unused(var)
|
||||
stack.push(local)
|
||||
return stack
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue