diff --git a/Lib/test/test_dis.py b/Lib/test/test_dis.py index 28da3fd8cf5..cb35175d206 100644 --- a/Lib/test/test_dis.py +++ b/Lib/test/test_dis.py @@ -808,8 +808,9 @@ dis_extended_arg_quick_code = """\ %3d 2 LOAD_CONST 1 (Ellipsis) 4 EXTENDED_ARG 1 6 UNPACK_EX 256 - 8 STORE_FAST_STORE_FAST 0 (_, _) - 10 RETURN_CONST 0 (None) + 8 POP_TOP + 10 STORE_FAST 0 (_) + 12 RETURN_CONST 0 (None) """% (extended_arg_quick.__code__.co_firstlineno, extended_arg_quick.__code__.co_firstlineno + 1,) diff --git a/Lib/test/test_peepholer.py b/Lib/test/test_peepholer.py index c57016bb108..82b0b50d0ea 100644 --- a/Lib/test/test_peepholer.py +++ b/Lib/test/test_peepholer.py @@ -1077,13 +1077,45 @@ class DirectCfgOptimizerTests(CfgOptimizationTestCase): expected_insts = [ ('LOAD_CONST', 0, 1), ('LOAD_CONST', 1, 2), - ('LOAD_CONST', 2, 3), - ('SWAP', 3, 4), - ('STORE_FAST_STORE_FAST', 17, 4), + ('NOP', 0, 3), + ('STORE_FAST', 1, 4), ('POP_TOP', 0, 4), ('RETURN_VALUE', 5) ] self.cfg_optimization_test(insts, expected_insts, consts=list(range(3)), nlocals=1) + def test_dead_store_elimination_in_same_lineno(self): + insts = [ + ('LOAD_CONST', 0, 1), + ('LOAD_CONST', 1, 2), + ('LOAD_CONST', 2, 3), + ('STORE_FAST', 1, 4), + ('STORE_FAST', 1, 4), + ('STORE_FAST', 1, 4), + ('RETURN_VALUE', 5) + ] + expected_insts = [ + ('LOAD_CONST', 0, 1), + ('LOAD_CONST', 1, 2), + ('NOP', 0, 3), + ('POP_TOP', 0, 4), + ('STORE_FAST', 1, 4), + ('RETURN_VALUE', 5) + ] + self.cfg_optimization_test(insts, expected_insts, consts=list(range(3)), nlocals=1) + + def test_no_dead_store_elimination_in_different_lineno(self): + insts = [ + ('LOAD_CONST', 0, 1), + ('LOAD_CONST', 1, 2), + ('LOAD_CONST', 2, 3), + ('STORE_FAST', 1, 4), + ('STORE_FAST', 1, 5), + ('STORE_FAST', 1, 6), + ('RETURN_VALUE', 5) + ] + self.cfg_optimization_test(insts, insts, consts=list(range(3)), nlocals=1) + + if __name__ == "__main__": unittest.main() diff --git a/Misc/NEWS.d/next/Core and Builtins/2023-06-05-23-38-43.gh-issue-104635.VYZhVh.rst b/Misc/NEWS.d/next/Core and Builtins/2023-06-05-23-38-43.gh-issue-104635.VYZhVh.rst new file mode 100644 index 00000000000..f20ddb56d17 --- /dev/null +++ b/Misc/NEWS.d/next/Core and Builtins/2023-06-05-23-38-43.gh-issue-104635.VYZhVh.rst @@ -0,0 +1,2 @@ +Eliminate redundant :opcode:`STORE_FAST` instructions in the compiler. Patch +by Dong-hee Na and Carl Meyer. diff --git a/Python/flowgraph.c b/Python/flowgraph.c index 2fd9a85b6d9..b16b508fe76 100644 --- a/Python/flowgraph.c +++ b/Python/flowgraph.c @@ -1515,15 +1515,18 @@ optimize_basic_block(PyObject *const_cache, basicblock *bb, PyObject *consts) */ } break; + case STORE_FAST: + if (opcode == nextop && + oparg == bb->b_instr[i+1].i_oparg && + bb->b_instr[i].i_loc.lineno == bb->b_instr[i+1].i_loc.lineno) { + bb->b_instr[i].i_opcode = POP_TOP; + bb->b_instr[i].i_oparg = 0; + } + break; case SWAP: if (oparg == 1) { INSTR_SET_OP0(inst, NOP); - break; } - if (swaptimize(bb, &i) < 0) { - goto error; - } - apply_static_swaps(bb, i); break; case KW_NAMES: break; @@ -1538,6 +1541,16 @@ optimize_basic_block(PyObject *const_cache, basicblock *bb, PyObject *consts) assert (!HAS_CONST(inst->i_opcode)); } } + + for (int i = 0; i < bb->b_iused; i++) { + cfg_instr *inst = &bb->b_instr[i]; + if (inst->i_opcode == SWAP) { + if (swaptimize(bb, &i) < 0) { + goto error; + } + apply_static_swaps(bb, i); + } + } return SUCCESS; error: return ERROR;