JUMP_IF_FALSE_OR_POP

iritkatriel · iritkatriel · commit 253ec9b95b09 · 2023-02-01T15:39:00.000Z
diff --git a/Python/bytecodes.c b/Python/bytecodes.c
@@ -1992,25 +1992,24 @@ dummy_func(
             }
         }
 
-        // error: JUMP_IF_FALSE_OR_POP stack effect depends on jump flag
-        inst(JUMP_IF_FALSE_OR_POP) {
-            PyObject *cond = TOP();
+        inst(JUMP_IF_FALSE_OR_POP, (cond -- cond if (jump))) {
+            bool jump = false;
             int err;
             if (Py_IsTrue(cond)) {
-                STACK_SHRINK(1);
                 _Py_DECREF_NO_DEALLOC(cond);
             }
             else if (Py_IsFalse(cond)) {
                 JUMPBY(oparg);
+                jump = true;
             }
             else {
                 err = PyObject_IsTrue(cond);
                 if (err > 0) {
-                    STACK_SHRINK(1);
                     Py_DECREF(cond);
                 }
                 else if (err == 0) {
                     JUMPBY(oparg);
+                    jump = true;
                 }
                 else {
                     goto error;
diff --git a/Python/compile.c b/Python/compile.c
@@ -8630,17 +8630,19 @@ opcode_metadata_is_sane(cfg_builder *g) {
             int opcode = instr->i_opcode;
             int oparg = instr->i_oparg;
             assert(opcode <= MAX_REAL_OPCODE);
-            int popped = _PyOpcode_num_popped(opcode, oparg);
-            int pushed = _PyOpcode_num_pushed(opcode, oparg);
-            assert((pushed < 0) == (popped < 0));
-            if (pushed >= 0) {
-                assert(_PyOpcode_opcode_metadata[opcode].valid_entry);
-                int effect = stack_effect(opcode, instr->i_oparg, -1);
-                if (effect != pushed - popped) {
-                   fprintf(stderr,
-                           "op=%d: stack_effect (%d) != pushed (%d) - popped (%d)\n",
-                           opcode, effect, pushed, popped);
-                   result = false;
+            for (int jump = 0; jump <= 1; jump++) {
+                int popped = _PyOpcode_num_popped(opcode, oparg, jump ? true : false);
+                int pushed = _PyOpcode_num_pushed(opcode, oparg, jump ? true : false);
+                assert((pushed < 0) == (popped < 0));
+                if (pushed >= 0) {
+                    assert(_PyOpcode_opcode_metadata[opcode].valid_entry);
+                    int effect = stack_effect(opcode, instr->i_oparg, jump);
+                    if (effect != pushed - popped) {
+                       fprintf(stderr,
+                               "op=%d arg=%d jump=%d: stack_effect (%d) != pushed (%d) - popped (%d)\n",
+                               opcode, oparg, jump, effect, pushed, popped);
+                       result = false;
+                    }
                 }
             }
         }
diff --git a/Python/generated_cases.c.h b/Python/generated_cases.c.h
diff --git a/Python/opcode_metadata.h b/Python/opcode_metadata.h
@@ -4,7 +4,7 @@
 
 #ifndef NDEBUG
 static int
-_PyOpcode_num_popped(int opcode, int oparg) {
+_PyOpcode_num_popped(int opcode, int oparg, bool jump) {
     switch(opcode) {
         case NOP:
             return 0;
@@ -241,7 +241,7 @@ _PyOpcode_num_popped(int opcode, int oparg) {
         case POP_JUMP_IF_NONE:
             return 1;
         case JUMP_IF_FALSE_OR_POP:
-            return -1;
+            return 1;
         case JUMP_IF_TRUE_OR_POP:
             return -1;
         case JUMP_BACKWARD_NO_INTERRUPT:
@@ -350,7 +350,7 @@ _PyOpcode_num_popped(int opcode, int oparg) {
 
 #ifndef NDEBUG
 static int
-_PyOpcode_num_pushed(int opcode, int oparg) {
+_PyOpcode_num_pushed(int opcode, int oparg, bool jump) {
     switch(opcode) {
         case NOP:
             return 0;
@@ -587,7 +587,7 @@ _PyOpcode_num_pushed(int opcode, int oparg) {
         case POP_JUMP_IF_NONE:
             return 0;
         case JUMP_IF_FALSE_OR_POP:
-            return -1;
+            return (jump ? 1 : 0);
         case JUMP_IF_TRUE_OR_POP:
             return -1;
         case JUMP_BACKWARD_NO_INTERRUPT:
diff --git a/Tools/cases_generator/generate_cases.py b/Tools/cases_generator/generate_cases.py
@@ -868,7 +868,7 @@ def write_function(
         ) -> None:
             self.out.emit("\n#ifndef NDEBUG")
             self.out.emit("static int")
-            self.out.emit(f"_PyOpcode_num_{direction}(int opcode, int oparg) {{")
+            self.out.emit(f"_PyOpcode_num_{direction}(int opcode, int oparg, bool jump) {{")
             self.out.emit("    switch(opcode) {")
             for instr, effect in data:
                 self.out.emit(f"        case {instr.name}:")

Original file line number	Diff line number	Diff line change
`@@ -1992,25 +1992,24 @@ dummy_func(`
`1992`	`1992`	`}`
`1993`	`1993`	`}`
`1994`	`1994`
`1995`		`- // error: JUMP_IF_FALSE_OR_POP stack effect depends on jump flag`
`1996`		`- inst(JUMP_IF_FALSE_OR_POP) {`
`1997`		`- PyObject *cond = TOP();`
	`1995`	`+ inst(JUMP_IF_FALSE_OR_POP, (cond -- cond if (jump))) {`
	`1996`	`+ bool jump = false;`
`1998`	`1997`	`int err;`
`1999`	`1998`	`if (Py_IsTrue(cond)) {`
`2000`		`- STACK_SHRINK(1);`
`2001`	`1999`	`_Py_DECREF_NO_DEALLOC(cond);`
`2002`	`2000`	`}`
`2003`	`2001`	`else if (Py_IsFalse(cond)) {`
`2004`	`2002`	`JUMPBY(oparg);`
	`2003`	`+ jump = true;`
`2005`	`2004`	`}`
`2006`	`2005`	`else {`
`2007`	`2006`	`err = PyObject_IsTrue(cond);`
`2008`	`2007`	`if (err > 0) {`
`2009`		`- STACK_SHRINK(1);`
`2010`	`2008`	`Py_DECREF(cond);`
`2011`	`2009`	`}`
`2012`	`2010`	`else if (err == 0) {`
`2013`	`2011`	`JUMPBY(oparg);`
	`2012`	`+ jump = true;`
`2014`	`2013`	`}`
`2015`	`2014`	`else {`
`2016`	`2015`	`goto error;`