bpo-45885: Don't un-adapt `COMPARE_OP` when collecting stats (GH-31516)

diff --git a/Misc/NEWS.d/next/Core and Builtins/2022-02-22-15-48-32.bpo-45885.W2vkaI.rst b/Misc/NEWS.d/next/Core and Builtins/2022-02-22-15-48-32.bpo-45885.W2vkaI.rst
new file mode 100644 (file)
index 0000000..4339f50
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2022-02-22-15-48-32.bpo-45885.W2vkaI.rst
@@ -0,0 +1 @@
+Don't un-adapt :opcode:`COMPARE_OP` when collecting specialization stats.

diff --git a/Python/specialize.c b/Python/specialize.c
index 91010a5be3c06c4191836b7990a5e6d581d0a9bd..0fc992d30bdc8489d14748cd2649c89ad2556bc3 100644 (file)
--- a/Python/specialize.c
+++ b/Python/specialize.c
@@ -2013,9 +2013,15 @@ _Py_Specialize_CompareOp(PyObject *lhs, PyObject *rhs,
     int op = adaptive->original_oparg;
     int next_opcode = _Py_OPCODE(instr[1]);
     if (next_opcode != POP_JUMP_IF_FALSE && next_opcode != POP_JUMP_IF_TRUE) {
-        // Can't ever combine, so don't don't bother being adaptive.
-        SPECIALIZATION_FAIL(COMPARE_OP, SPEC_FAIL_COMPARE_OP_NOT_FOLLOWED_BY_COND_JUMP);
+        // Can't ever combine, so don't don't bother being adaptive (unless
+        // we're collecting stats, where it's more important to get accurate hit
+        // counts for the unadaptive version and each of the different failure
+        // types):
+#ifndef Py_STATS
         *instr = _Py_MAKECODEUNIT(COMPARE_OP, adaptive->original_oparg);
+        return;
+#endif
+        SPECIALIZATION_FAIL(COMPARE_OP, SPEC_FAIL_COMPARE_OP_NOT_FOLLOWED_BY_COND_JUMP);
         goto failure;
     }
     assert(op <= Py_GE);