[Python-checkins] bpo-32439: Clean up the code for compiling comparison expressions. (#5029)

Sat Dec 30 02:47:48 EST 2017

https://github.com/python/cpython/commit/02b9ef27752ff4873c592ac3afe7e3410f715984
commit: 02b9ef27752ff4873c592ac3afe7e3410f715984
branch: master
author: Serhiy Storchaka <storchaka at gmail.com>
committer: GitHub <noreply at github.com>
date: 2017年12月30日T09:47:42+02:00
summary:
bpo-32439: Clean up the code for compiling comparison expressions. (#5029)
files:
M Python/compile.c

diff --git a/Python/compile.c b/Python/compile.c
index e5745d16e30..cd039168eba 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -3420,35 +3420,32 @@ static int
 compiler_compare(struct compiler *c, expr_ty e)
 {
 Py_ssize_t i, n;
- basicblock *cleanup = NULL;
 
- /* XXX the logic can be cleaned up for 1 or multiple comparisons */
 VISIT(c, expr, e->v.Compare.left);
- n = asdl_seq_LEN(e->v.Compare.ops);
- assert(n > 0);
- if (n > 1) {
- cleanup = compiler_new_block(c);
+ assert(asdl_seq_LEN(e->v.Compare.ops) > 0);
+ n = asdl_seq_LEN(e->v.Compare.ops) - 1;
+ if (n == 0) {
+ VISIT(c, expr, (expr_ty)asdl_seq_GET(e->v.Compare.comparators, 0));
+ ADDOP_I(c, COMPARE_OP,
+ cmpop((cmpop_ty)(asdl_seq_GET(e->v.Compare.ops, 0))));
+ }
+ else {
+ basicblock *cleanup = compiler_new_block(c);
 if (cleanup == NULL)
 return 0;
- VISIT(c, expr,
- (expr_ty)asdl_seq_GET(e->v.Compare.comparators, 0));
- }
- for (i = 1; i < n; i++) {
- ADDOP(c, DUP_TOP);
- ADDOP(c, ROT_THREE);
- ADDOP_I(c, COMPARE_OP,
- cmpop((cmpop_ty)(asdl_seq_GET(
- e->v.Compare.ops, i - 1))));
- ADDOP_JABS(c, JUMP_IF_FALSE_OR_POP, cleanup);
- NEXT_BLOCK(c);
- if (i < (n - 1))
+ for (i = 0; i < n; i++) {
 VISIT(c, expr,
 (expr_ty)asdl_seq_GET(e->v.Compare.comparators, i));
- }
- VISIT(c, expr, (expr_ty)asdl_seq_GET(e->v.Compare.comparators, n - 1));
- ADDOP_I(c, COMPARE_OP,
- cmpop((cmpop_ty)(asdl_seq_GET(e->v.Compare.ops, n - 1))));
- if (n > 1) {
+ ADDOP(c, DUP_TOP);
+ ADDOP(c, ROT_THREE);
+ ADDOP_I(c, COMPARE_OP,
+ cmpop((cmpop_ty)(asdl_seq_GET(e->v.Compare.ops, i))));
+ ADDOP_JABS(c, JUMP_IF_FALSE_OR_POP, cleanup);
+ NEXT_BLOCK(c);
+ }
+ VISIT(c, expr, (expr_ty)asdl_seq_GET(e->v.Compare.comparators, n));
+ ADDOP_I(c, COMPARE_OP,
+ cmpop((cmpop_ty)(asdl_seq_GET(e->v.Compare.ops, n))));
 basicblock *end = compiler_new_block(c);
 if (end == NULL)
 return 0;
