[Python-checkins] gh-104909: Implement conditional stack effects for macros (#105748)
gvanrossum
webhook-mailer at python.org
Wed Jun 14 16:50:52 EDT 2023
https://github.com/python/cpython/commit/4caa728b2c78c5ded7c91579f21fbb67e3867d80
commit: 4caa728b2c78c5ded7c91579f21fbb67e3867d80
branch: main
author: Guido van Rossum <guido at python.org>
committer: gvanrossum <gvanrossum at gmail.com>
date: 2023-06-14T20:50:48Z
summary:
gh-104909: Implement conditional stack effects for macros (#105748)
files:
M Tools/cases_generator/generate_cases.py
M Tools/cases_generator/test_generator.py
diff --git a/Tools/cases_generator/generate_cases.py b/Tools/cases_generator/generate_cases.py
index 8d5739f307ab..544568e0294e 100644
--- a/Tools/cases_generator/generate_cases.py
+++ b/Tools/cases_generator/generate_cases.py
@@ -179,14 +179,12 @@ def block(self, head: str):
def stack_adjust(
self,
- diff: int,
input_effects: list[StackEffect],
output_effects: list[StackEffect],
):
- # TODO: Get rid of 'diff' parameter
shrink, isym = list_effect_size(input_effects)
grow, osym = list_effect_size(output_effects)
- diff += grow - shrink
+ diff = grow - shrink
if isym and isym != osym:
self.emit(f"STACK_SHRINK({isym});")
if diff < 0:
@@ -355,7 +353,6 @@ def write(self, out: Formatter) -> None:
# Write net stack growth/shrinkage
out.stack_adjust(
- 0,
[ieff for ieff in self.input_effects],
[oeff for oeff in self.output_effects],
)
@@ -848,9 +845,14 @@ def stack_analysis(
Ignore cache effects.
- Return the list of variable names and the initial stack pointer.
+ Return the list of variables (as StackEffects) and the initial stack pointer.
"""
lowest = current = highest = 0
+ conditions: dict[int, str] = {} # Indexed by 'current'.
+ last_instr: Instruction | None = None
+ for thing in components:
+ if isinstance(thing, Instruction):
+ last_instr = thing
for thing in components:
match thing:
case Instruction() as instr:
@@ -863,9 +865,24 @@ def stack_analysis(
"which are not supported in macro instructions",
instr.inst, # TODO: Pass name+location of macro
)
+ if any(eff.cond for eff in instr.input_effects):
+ self.error(
+ f"Instruction {instr.name!r} has conditional input stack effect, "
+ "which are not supported in macro instructions",
+ instr.inst, # TODO: Pass name+location of macro
+ )
+ if any(eff.cond for eff in instr.output_effects) and instr is not last_instr:
+ self.error(
+ f"Instruction {instr.name!r} has conditional output stack effect, "
+ "but is not the last instruction in a macro",
+ instr.inst, # TODO: Pass name+location of macro
+ )
current -= len(instr.input_effects)
lowest = min(lowest, current)
- current += len(instr.output_effects)
+ for eff in instr.output_effects:
+ if eff.cond:
+ conditions[current] = eff.cond
+ current += 1
highest = max(highest, current)
case parser.CacheEffect():
pass
@@ -874,9 +891,9 @@ def stack_analysis(
# At this point, 'current' is the net stack effect,
# and 'lowest' and 'highest' are the extremes.
# Note that 'lowest' may be negative.
- # TODO: Reverse the numbering.
stack = [
- StackEffect(f"_tmp_{i+1}", "") for i in reversed(range(highest - lowest))
+ StackEffect(f"_tmp_{i}", "", conditions.get(highest - i, ""))
+ for i in reversed(range(1, highest - lowest + 1))
]
return stack, -lowest
@@ -908,6 +925,7 @@ def effect_str(effects: list[StackEffect]) -> str:
low = 0
sp = 0
high = 0
+ pushed_symbolic: list[str] = []
for comp in parts:
for effect in comp.instr.input_effects:
assert not effect.cond, effect
@@ -915,8 +933,9 @@ def effect_str(effects: list[StackEffect]) -> str:
sp -= 1
low = min(low, sp)
for effect in comp.instr.output_effects:
- assert not effect.cond, effect
assert not effect.size, effect
+ if effect.cond:
+ pushed_symbolic.append(maybe_parenthesize(f"{maybe_parenthesize(effect.cond)} ? 1 : 0"))
sp += 1
high = max(sp, high)
if high != max(0, sp):
@@ -926,7 +945,8 @@ def effect_str(effects: list[StackEffect]) -> str:
# calculations to use the micro ops.
self.error("Macro has virtual stack growth", thing)
popped = str(-low)
- pushed = str(sp - low)
+ pushed_symbolic.append(str(sp - low - len(pushed_symbolic)))
+ pushed = " + ".join(pushed_symbolic)
case parser.Pseudo():
instr = self.pseudo_instrs[thing.name]
popped = pushed = None
@@ -1203,7 +1223,15 @@ def wrap_macro(self, mac: MacroInstruction):
with self.out.block(f"TARGET({mac.name})"):
if mac.predicted:
self.out.emit(f"PREDICTED({mac.name});")
- for i, var in reversed(list(enumerate(mac.stack))):
+
+ # The input effects should have no conditionals.
+ # Only the output effects do (for now).
+ ieffects = [
+ StackEffect(eff.name, eff.type) if eff.cond else eff
+ for eff in mac.stack
+ ]
+
+ for i, var in reversed(list(enumerate(ieffects))):
src = None
if i < mac.initial_sp:
src = StackEffect(f"stack_pointer[-{mac.initial_sp - i}]", "")
@@ -1211,8 +1239,7 @@ def wrap_macro(self, mac: MacroInstruction):
yield
- # TODO: Use slices of mac.stack instead of numeric values
- self.out.stack_adjust(mac.final_sp - mac.initial_sp, [], [])
+ self.out.stack_adjust(ieffects[:mac.initial_sp], mac.stack[:mac.final_sp])
for i, var in enumerate(reversed(mac.stack[: mac.final_sp]), 1):
dst = StackEffect(f"stack_pointer[-{i}]", "")
diff --git a/Tools/cases_generator/test_generator.py b/Tools/cases_generator/test_generator.py
index f8c79976fb72..9ff4c971fd21 100644
--- a/Tools/cases_generator/test_generator.py
+++ b/Tools/cases_generator/test_generator.py
@@ -432,3 +432,43 @@ def test_cond_effect():
}
"""
run_cases_test(input, output)
+
+def test_macro_cond_effect():
+ input = """
+ op(A, (left, middle, right --)) {
+ # Body of A
+ }
+ op(B, (-- deep, extra if (oparg), res)) {
+ # Body of B
+ }
+ macro(M) = A + B;
+ """
+ output = """
+ TARGET(M) {
+ PyObject *_tmp_1 = stack_pointer[-1];
+ PyObject *_tmp_2 = stack_pointer[-2];
+ PyObject *_tmp_3 = stack_pointer[-3];
+ {
+ PyObject *right = _tmp_1;
+ PyObject *middle = _tmp_2;
+ PyObject *left = _tmp_3;
+ # Body of A
+ }
+ {
+ PyObject *deep;
+ PyObject *extra = NULL;
+ PyObject *res;
+ # Body of B
+ _tmp_3 = deep;
+ if (oparg) { _tmp_2 = extra; }
+ _tmp_1 = res;
+ }
+ STACK_SHRINK(1);
+ STACK_GROW((oparg ? 1 : 0));
+ stack_pointer[-1] = _tmp_1;
+ if (oparg) { stack_pointer[-2] = _tmp_2; }
+ stack_pointer[-3] = _tmp_3;
+ DISPATCH();
+ }
+ """
+ run_cases_test(input, output)
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