From afd842f5b262bfe5e2e2e53762d748b5da6caf2c Mon Sep 17 00:00:00 2001 From: Raymond Hettinger Date: Sun, 20 Feb 2005 12:46:54 +0000 Subject: [PATCH] Teach the peepholer to fold unary operations on constants. Afterwards, -0.5 loads in a single step and no longer requires a runtime UNARY_NEGATIVE operation. --- Lib/test/test_peepholer.py | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/Lib/test/test_peepholer.py b/Lib/test/test_peepholer.py index 34bd99f2a4..4385a84c1f 100644 --- a/Lib/test/test_peepholer.py +++ b/Lib/test/test_peepholer.py @@ -133,6 +133,25 @@ class TestTranforms(unittest.TestCase): asm = dis_single('a="x"*1000') self.assert_('(1000)' in asm) + def test_folding_of_unaryops_on_constants(self): + for line, elem in ( + ('`1`', "('1')"), # unary convert + ('-0.5', '(-0.5)'), # unary negative + ('~-2', '(1)'), # unary invert + ): + asm = dis_single(line) + self.assert_(elem in asm, asm) + self.assert_('UNARY_' not in asm) + + # Verify that unfoldables are skipped + for line, elem in ( + ('-"abc"', "('abc')"), # unary negative + ('~"abc"', "('abc')"), # unary invert + ): + asm = dis_single(line) + self.assert_(elem in asm, asm) + self.assert_('UNARY_' in asm) + def test_elim_extra_return(self): # RETURN LOAD_CONST None RETURN --> RETURN def f(x): -- 2.40.0