From 3db762db72cc0da938614b1e414abb1e12ca4094 Mon Sep 17 00:00:00 2001
From: penguin_wwy <940375606@qq.com>
Date: Thu, 6 Jan 2022 19:38:35 +0800
Subject: bpo-46031: add POP_JUMP_IF_NOT_NONE and POP_JUMP_IF_NONE (GH-30019)

---
 Python/compile.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

(limited to 'Python/compile.c')

diff --git a/Python/compile.c b/Python/compile.c
index 3a390751fe2..625a07bd396 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -1110,6 +1110,8 @@ stack_effect(int opcode, int oparg, int jump)
 
         case POP_JUMP_IF_FALSE:
         case POP_JUMP_IF_TRUE:
+        case POP_JUMP_IF_NONE:
+        case POP_JUMP_IF_NOT_NONE:
             return -1;
 
         case LOAD_GLOBAL:
@@ -8519,6 +8521,21 @@ optimize_basic_block(struct compiler *c, basicblock *bb, PyObject *consts)
                             bb->b_instr[i+1].i_opcode = NOP;
                         }
                         break;
+                    case IS_OP:
+                        cnt = get_const_value(inst->i_opcode, oparg, consts);
+                        if (cnt == NULL) {
+                            goto error;
+                        }
+                        int jump_op = i+2 < bb->b_iused ? bb->b_instr[i+2].i_opcode : 0;
+                        if (Py_IsNone(cnt) && (jump_op == POP_JUMP_IF_FALSE || jump_op == POP_JUMP_IF_TRUE)) {
+                            unsigned char nextarg = bb->b_instr[i+1].i_oparg;
+                            inst->i_opcode = NOP;
+                            bb->b_instr[i+1].i_opcode = NOP;
+                            bb->b_instr[i+2].i_opcode = nextarg ^ (jump_op == POP_JUMP_IF_FALSE) ?
+                                    POP_JUMP_IF_NOT_NONE : POP_JUMP_IF_NONE;
+                        }
+                        Py_DECREF(cnt);
+                        break;
                 }
                 break;
             }
@@ -8611,6 +8628,14 @@ optimize_basic_block(struct compiler *c, basicblock *bb, PyObject *consts)
                         break;
                 }
                 break;
+            case POP_JUMP_IF_NOT_NONE:
+            case POP_JUMP_IF_NONE:
+                switch (target->i_opcode) {
+                    case JUMP_ABSOLUTE:
+                    case JUMP_FORWARD:
+                        i -= jump_thread(inst, target, inst->i_opcode);
+                }
+                break;
             case POP_JUMP_IF_FALSE:
                 switch (target->i_opcode) {
                     case JUMP_ABSOLUTE:
@@ -8766,6 +8791,8 @@ normalize_basic_block(basicblock *bb) {
             case JUMP_FORWARD:
                 bb->b_nofallthrough = 1;
                 /* fall through */
+            case POP_JUMP_IF_NOT_NONE:
+            case POP_JUMP_IF_NONE:
             case POP_JUMP_IF_FALSE:
             case POP_JUMP_IF_TRUE:
             case JUMP_IF_FALSE_OR_POP:
-- 
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