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bpo-37269: Correctly optimize constant conditionals of binops #14071

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pablogsal merged 4 commits into from
Jun 14, 2019
Merged

bpo-37269: Correctly optimize constant conditionals of binops #14071

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Correctly optimize constant conditionals of binops
pablogsal Jun 14, 2019
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7 changes: 7 additions & 0 deletions Lib/test/test_peepholer.py
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Original file line number Diff line number Diff line change
Expand Up @@ -414,6 +414,13 @@ def forloop():
pass
self.assertEqual(count_instr_recursively(forloop, 'BUILD_LIST'), 0)

def test_condition_with_binop_with_bools(self):
def f():
if True or False:
return 1
return 0
self.assertEqual(f(), 1)


class TestBuglets(unittest.TestCase):

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2 changes: 2 additions & 0 deletions Misc/NEWS.d/next/Core and Builtins/2019-06-14-06-32-33.bpo-37269.SjVVAe.rst
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@@ -0,0 +1,2 @@
Fix a bug in the peephole optimizer that was not treating correctly constant
conditions with binary operators. Patch by Pablo Galindo.
5 changes: 5 additions & 0 deletions Python/peephole.c
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Expand Up @@ -315,6 +315,11 @@ PyCode_Optimize(PyObject *code, PyObject* consts, PyObject *names,
fill_nops(codestr, op_start, nexti + 1);
cumlc = 0;
} else if (is_true == 0) {
if (i > 1 &&
(_Py_OPCODE(codestr[i - 1]) == POP_JUMP_IF_TRUE ||
_Py_OPCODE(codestr[i - 1]) == POP_JUMP_IF_FALSE)) {
break;
}
h = get_arg(codestr, nexti) / sizeof(_Py_CODEUNIT);
tgt = find_op(codestr, codelen, h);
fill_nops(codestr, op_start, tgt);
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