From: Pablo Galindo <Pablogsal@gmail.com>
Date: Fri, 14 Jun 2019 05:54:53 +0000 (+0100)
Subject: bpo-37269: Correctly optimise conditionals with constant booleans (GH-14071)
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=05f831865545b08c9a21cfb7773af58b76ec64cb;p=python
bpo-37269: Correctly optimise conditionals with constant booleans (GH-14071)
Fix a regression introduced by af8646c8054d0f4180a2013383039b6a472f9698 that was causing code of the form:
if True and False:
do_something()
to be optimized incorrectly, eliminating the block.
---
diff --git a/Lib/test/test_peepholer.py b/Lib/test/test_peepholer.py
index 860ceeb003..5d00240e25 100644
--- a/Lib/test/test_peepholer.py
+++ b/Lib/test/test_peepholer.py
@@ -414,6 +414,13 @@ class TestTranforms(BytecodeTestCase):
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):
diff --git a/Misc/NEWS.d/next/Core and Builtins/2019-06-14-06-32-33.bpo-37269.SjVVAe.rst b/Misc/NEWS.d/next/Core and Builtins/2019-06-14-06-32-33.bpo-37269.SjVVAe.rst
new file mode 100644
index 0000000000..b9b7906677
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2019-06-14-06-32-33.bpo-37269.SjVVAe.rst
@@ -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.
diff --git a/Python/peephole.c b/Python/peephole.c
index 6f3e2ed88b..d7b1dfc4d9 100644
--- a/Python/peephole.c
+++ b/Python/peephole.c
@@ -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);