jit-trace: seed keyword-only defaults from a namespace mapping, and ask the is-None scan about the operand the branch tests

pyre/bench/synth/is_none_unboxed_operand_decline.cranelift.jitstats

@@ -0,0 +1,18 @@
+bridges_compiled=0
+descr_set_absent=0
+descr_set_ambiguous=0
+descr_set_stale_absent=0
+fbw_blackhole_adopted_multi_frame=0
+fbw_blackhole_adopted_single_frame=0
+fbw_escape_plain_fallback=0
+fbw_escape_plain_fallback_unclean=0
+fbw_midbody_latch_new_unjournaled=0
+fbw_rolled_back_with_effects=0
+fbw_store_journal_rollback_failed=0
+field_pos_attached_misplaced=0
+field_pos_spec_misplaced=0
+guard_failures=2
+internal_compile_panics=0
+loops_aborted=0
+loops_compiled=2
+retraces_compiled=0

pyre/bench/synth/is_none_unboxed_operand_decline.dynasm.jitstats

@@ -0,0 +1,18 @@
+bridges_compiled=0
+descr_set_absent=0
+descr_set_ambiguous=0
+descr_set_stale_absent=0
+fbw_blackhole_adopted_multi_frame=0
+fbw_blackhole_adopted_single_frame=0
+fbw_escape_plain_fallback=0
+fbw_escape_plain_fallback_unclean=0
+fbw_midbody_latch_new_unjournaled=0
+fbw_rolled_back_with_effects=0
+fbw_store_journal_rollback_failed=0
+field_pos_attached_misplaced=0
+field_pos_spec_misplaced=0
+guard_failures=2
+internal_compile_panics=0
+loops_aborted=0
+loops_compiled=2
+retraces_compiled=0

pyre/bench/synth/is_none_unboxed_operand_decline.py

@@ -0,0 +1,28 @@
+# `optional_none_arg_inline` with the default changed from `None` to an int, so
+# the local the `is`-against-None branch tests is the one the callee's register
+# banks hold unboxed.  That is the case the scan exists for: a mid-body guard
+# resume cannot source the operand's Ref form from those banks, the encoded
+# liveness stream disagrees with the decoder and the caller frame is corrupted.
+# `_read_from_buffer(self, size=-1)` was the shape that miscompiled.
+#
+# The gate is `loops_compiled` reading 2 -- the callee keeps a trace of its own.
+# Dropping the scan folds it into the caller's and the count falls to 1, which
+# is the movement this fixture is here to catch.
+N = 200000
+
+
+def read_n(buf, size=-1):
+    if size is None or size < 0:
+        return buf
+    return size
+
+
+def main():
+    total = 0
+    for i in range(N):
+        total += read_n(i)
+    total += read_n(1, 7)
+    print(total)
+
+
+main()

pyre/bench/synth/is_none_unboxed_operand_decline.wasm.jitstats

@@ -0,0 +1,18 @@
+bridges_compiled=0
+descr_set_absent=0
+descr_set_ambiguous=0
+descr_set_stale_absent=0
+fbw_blackhole_adopted_multi_frame=0
+fbw_blackhole_adopted_single_frame=0
+fbw_escape_plain_fallback=0
+fbw_escape_plain_fallback_unclean=0
+fbw_midbody_latch_new_unjournaled=0
+fbw_rolled_back_with_effects=0
+fbw_store_journal_rollback_failed=0
+field_pos_attached_misplaced=0
+field_pos_spec_misplaced=0
+guard_failures=2
+internal_compile_panics=0
+loops_aborted=0
+loops_compiled=2
+retraces_compiled=0

pyre/bench/synth/kwdefaults_invalidation.py

@@ -0,0 +1,95 @@
+# pyre-check: selfcheck
+# pyre-check: selfcheck-compiles=hot
+# pyre-check: spec-folds=kwonly_defaults_inline
+# Self-checking guard for the pins under an inlined callee's keyword-only
+# defaults.
+#
+# Seeding those locals no longer probes `__kwdefaults__` per call.  The mapping
+# a definition builds carries a version, so the walker bakes each entry's cell,
+# records a quasi-immutable marker on `Function.w_kw_defs` and one on the
+# mapping's strategy version, drains both with a single `GuardNotInvalidated`,
+# and reads the cell's field live.  Three separate mechanisms therefore stand
+# between a mutation and the next call, and a census can only say the fold
+# fired -- not that the pins are honest.  Each site below moves one of them and
+# prints a wrong number if that one is missing.
+#
+# Sites:
+#   A  overwrite an existing entry in place.  A cell that already holds an
+#      object absorbs the store and bumps no version, so nothing invalidates:
+#      this is answered by the live field read alone, and a fold that baked the
+#      VALUE rather than the cell keeps returning the old one.
+#   B  delete an entry, then add it back.  Both move the strategy version, and
+#      the deleted window is observable on its own -- the call must raise
+#      rather than seed a stale default.
+#   C  rebind the attribute.  `f.__kwdefaults__ = d` stores `d` itself, so only
+#      the `Function.w_kw_defs` marker can catch this; the version marker is
+#      still watching the old mapping, which no longer answers anything.
+#   D  keep calling after that rebind.  A plain dict has no version to pin, so
+#      the resolve declines and the callee seeds through the ordinary path --
+#      which must still see a later in-place mutation.
+N = 20000
+
+
+def g(x, *, step=1, tag="a"):
+    return x + step, tag
+
+
+def hot(n, want_step, want_tag):
+    """Run the loop hot and count answers that disagree with the mapping."""
+    bad = 0
+    for i in range(n):
+        value, tag = g(i)
+        if value != i + want_step or tag != want_tag:
+            bad += 1
+    return bad
+
+
+def main():
+    # Warm first so the sites below mutate a compiled loop rather than an
+    # interpreted one.
+    if hot(N, 1, "a"):
+        print("FAIL warm-up disagreed with the declared defaults")
+        return 1
+
+    g.__kwdefaults__["step"] = 5
+    bad = hot(N, 5, "a")
+    if bad:
+        print(f"FAIL site A missed an in-place overwrite on {bad} of {N} calls")
+        return 1
+
+    del g.__kwdefaults__["tag"]
+    missing = 0
+    for i in range(N):
+        try:
+            g(i)
+        except TypeError:
+            missing += 1
+    if missing != N:
+        print(f"FAIL site B seeded a deleted default on {N - missing} of {N} calls")
+        return 1
+
+    g.__kwdefaults__["tag"] = "z"
+    bad = hot(N, 5, "z")
+    if bad:
+        print(f"FAIL site B missed the re-added default on {bad} of {N} calls")
+        return 1
+
+    g.__kwdefaults__ = {"step": 9, "tag": "q"}
+    bad = hot(N, 9, "q")
+    if bad:
+        print(f"FAIL site C missed the rebound mapping on {bad} of {N} calls")
+        return 1
+
+    g.__kwdefaults__["step"] = 11
+    bad = hot(N, 11, "q")
+    if bad:
+        print(f"FAIL site D missed a mutation after the rebind on {bad} of {N} calls")
+        return 1
+
+    print("PASS kwdefaults invalidation")
+    return 0
+
+
+import sys
+
+sys.exit(main())

pyre/bench/synth/kwonly_default_callee_inline.py

@@ -1,4 +1,5 @@
 # pyre-check: max-pypy-ratio=16
+# pyre-check: spec-folds=kwonly_defaults_inline
 # A hot call into a keyword-only callee that supplies nothing for it, so the
 # inline has to fill `step` from `__kwdefaults__` itself.
 #

pyre/bench/synth/optional_none_arg_inline.cranelift.jitstats

@@ -0,0 +1,18 @@
+bridges_compiled=0
+descr_set_absent=0
+descr_set_ambiguous=0
+descr_set_stale_absent=0
+fbw_blackhole_adopted_multi_frame=0
+fbw_blackhole_adopted_single_frame=0
+fbw_escape_plain_fallback=0
+fbw_escape_plain_fallback_unclean=0
+fbw_midbody_latch_new_unjournaled=0
+fbw_rolled_back_with_effects=0
+fbw_store_journal_rollback_failed=0
+field_pos_attached_misplaced=0
+field_pos_spec_misplaced=0
+guard_failures=1
+internal_compile_panics=0
+loops_aborted=0
+loops_compiled=1
+retraces_compiled=0

pyre/bench/synth/optional_none_arg_inline.dynasm.jitstats

@@ -0,0 +1,18 @@
+bridges_compiled=0
+descr_set_absent=0
+descr_set_ambiguous=0
+descr_set_stale_absent=0
+fbw_blackhole_adopted_multi_frame=0
+fbw_blackhole_adopted_single_frame=0
+fbw_escape_plain_fallback=0
+fbw_escape_plain_fallback_unclean=0
+fbw_midbody_latch_new_unjournaled=0
+fbw_rolled_back_with_effects=0
+fbw_store_journal_rollback_failed=0
+field_pos_attached_misplaced=0
+field_pos_spec_misplaced=0
+guard_failures=1
+internal_compile_panics=0
+loops_aborted=0
+loops_compiled=1
+retraces_compiled=0

pyre/bench/synth/optional_none_arg_inline.py

@@ -0,0 +1,39 @@
+# pyre-check: max-pypy-ratio=8
+# A hot call into a callee that branches on `arg is None` -- the shape every
+# optional argument in the standard library takes.  The tested local holds the
+# default `None`, a Ref; the other parameter is an int.
+#
+# The gate is `loops_compiled` first: declined, the callee takes a trace of
+# its own and the count reads 2; inlined, it folds into the caller's and reads
+# 1.  That census is host-independent, which the ratio at this size is not:
+# the body is a single add, so pypy runs the whole loop well under
+# `EXEC_TIME_FLOOR_S` and the comparison marks it -- only the ceiling applies.
+# Sized up until pypy cleared the floor the fixture cost cpython a second, so
+# the counter stays the gate here, as it is for `kwonly_default_callee_inline`.
+#
+# Its sibling `is_none_unboxed_operand_decline` is this fixture with the
+# default changed from `None` to an int, and stays declined.  The pair is what
+# shows the `is`-against-None scan asking about the operand the branch tests
+# rather than about the signature as a whole.
+#
+# `clamp` is called once more off the hot path so the printed total depends on
+# the arm the trace guards away as well as the one it keeps: an identity test
+# answered the wrong way changes the sum rather than the timing.
+N = 200000
+
+
+def clamp(v, lo=None):
+    if lo is None:
+        return v
+    return lo
+
+
+def main():
+    total = 0
+    for i in range(N):
+        total += clamp(i)
+    total += clamp(1, 7)
+    print(total)
+
+
+main()

pyre/bench/synth/optional_none_arg_inline.wasm.jitstats

@@ -0,0 +1,18 @@
+bridges_compiled=0
+descr_set_absent=0
+descr_set_ambiguous=0
+descr_set_stale_absent=0
+fbw_blackhole_adopted_multi_frame=0
+fbw_blackhole_adopted_single_frame=0
+fbw_escape_plain_fallback=0
+fbw_escape_plain_fallback_unclean=0
+fbw_midbody_latch_new_unjournaled=0
+fbw_rolled_back_with_effects=0
+fbw_store_journal_rollback_failed=0
+field_pos_attached_misplaced=0
+field_pos_spec_misplaced=0
+guard_failures=1
+internal_compile_panics=0
+loops_aborted=0
+loops_compiled=1
+retraces_compiled=0