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gh-93554: Conditional jump opcodes only jump forward (GH-96318)

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Irit Katriel 2022-09-01 21:36:47 +01:00 • committed by GitHub
parent a91f25577c
commit 4c72517cad
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GPG key ID: 4AEE18F83AFDEB23
13 changed files with 298 additions and 448 deletions
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15
Python/specialize.c
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@ -1999,10 +1999,8 @@ _Py_Specialize_CompareOp(PyObject *lhs, PyObject *rhs, _Py_CODEUNIT *instr,
assert(_PyOpcode_Caches[COMPARE_OP] == INLINE_CACHE_ENTRIES_COMPARE_OP);
_PyCompareOpCache *cache = (_PyCompareOpCache *)(instr + 1);
int next_opcode = _Py_OPCODE(instr[INLINE_CACHE_ENTRIES_COMPARE_OP + 1]);
if (next_opcode != POP_JUMP_FORWARD_IF_FALSE &&
next_opcode != POP_JUMP_BACKWARD_IF_FALSE &&
next_opcode != POP_JUMP_FORWARD_IF_TRUE &&
next_opcode != POP_JUMP_BACKWARD_IF_TRUE) {
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 (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
@ -2021,14 +2019,9 @@ _Py_Specialize_CompareOp(PyObject *lhs, PyObject *rhs, _Py_CODEUNIT *instr,
}
assert(oparg <= Py_GE);
int when_to_jump_mask = compare_masks[oparg];
if (next_opcode == POP_JUMP_FORWARD_IF_FALSE ||
next_opcode == POP_JUMP_BACKWARD_IF_FALSE) {
if (next_opcode == POP_JUMP_IF_FALSE) {
when_to_jump_mask = (1 | 2 | 4) & ~when_to_jump_mask;
}
if (next_opcode == POP_JUMP_BACKWARD_IF_TRUE ||
next_opcode == POP_JUMP_BACKWARD_IF_FALSE) {
when_to_jump_mask <<= 3;
}
if (Py_TYPE(lhs) != Py_TYPE(rhs)) {
SPECIALIZATION_FAIL(COMPARE_OP, compare_op_fail_kind(lhs, rhs));
goto failure;
@ -2056,7 +2049,7 @@ _Py_Specialize_CompareOp(PyObject *lhs, PyObject *rhs, _Py_CODEUNIT *instr,
}
else {
_Py_SET_OPCODE(*instr, COMPARE_OP_STR_JUMP);
cache->mask = when_to_jump_mask;
cache->mask = (when_to_jump_mask & 2) == 0;
goto success;
}
}