GH-117062: Make _JUMP_TO_TOP a general absolute jump (GH-120854)

brandtbucher · web-flow · commit a47abdb45d4f · 2024-06-24T08:35:10.000-07:00
diff --git a/Python/bytecodes.c b/Python/bytecodes.c
@@ -4149,9 +4149,7 @@ dummy_func(
         }
 
         op(_JUMP_TO_TOP, (--)) {
-#ifndef _Py_JIT
-            next_uop = &current_executor->trace[1];
-#endif
+            JUMP_TO_JUMP_TARGET();
         }
 
         tier2 op(_SET_IP, (instr_ptr/4 --)) {
diff --git a/Python/executor_cases.c.h b/Python/executor_cases.c.h
diff --git a/Python/optimizer.c b/Python/optimizer.c
@@ -1059,6 +1059,11 @@ prepare_for_execution(_PyUOpInstruction *buffer, int length)
                 buffer[i].jump_target = 0;
             }
         }
+        if (opcode == _JUMP_TO_TOP) {
+            assert(buffer[0].opcode == _START_EXECUTOR);
+            buffer[i].format = UOP_FORMAT_JUMP;
+            buffer[i].jump_target = 1;
+        }
     }
     return next_spare;
 }
diff --git a/Tools/jit/_stencils.py b/Tools/jit/_stencils.py
@@ -42,8 +42,6 @@ class HoleValue(enum.Enum):
     ERROR_TARGET = enum.auto()
     # The index of the exit to be jumped through (exposed as _JIT_EXIT_INDEX):
     EXIT_INDEX = enum.auto()
-    # The base address of the machine code for the first uop (exposed as _JIT_TOP):
-    TOP = enum.auto()
     # A hardcoded value of zero (used for symbol lookups):
     ZERO = enum.auto()
 
@@ -110,7 +108,6 @@ class HoleValue(enum.Enum):
     HoleValue.JUMP_TARGET: "instruction_starts[instruction->jump_target]",
     HoleValue.ERROR_TARGET: "instruction_starts[instruction->error_target]",
     HoleValue.EXIT_INDEX: "instruction->exit_index",
-    HoleValue.TOP: "instruction_starts[1]",
     HoleValue.ZERO: "",
 }
 
diff --git a/Tools/jit/template.c b/Tools/jit/template.c
@@ -105,9 +105,6 @@ _JIT_ENTRY(_PyInterpreterFrame *frame, PyObject **stack_pointer, PyThreadState *
     UOP_STAT_INC(uopcode, execution_count);
 
     // The actual instruction definitions (only one will be used):
-    if (uopcode == _JUMP_TO_TOP) {
-        PATCH_JUMP(_JIT_TOP);
-    }
     switch (uopcode) {
 #include "executor_cases.c.h"
         default:

Original file line number	Diff line number	Diff line change
`@@ -4149,9 +4149,7 @@ dummy_func(`
`4149`	`4149`	`}`
`4150`	`4150`
`4151`	`4151`	`op(_JUMP_TO_TOP, (--)) {`
`4152`		`-#ifndef _Py_JIT`
`4153`		`- next_uop = &current_executor->trace[1];`
`4154`		`-#endif`
	`4152`	`+ JUMP_TO_JUMP_TARGET();`
`4155`	`4153`	`}`
`4156`	`4154`
`4157`	`4155`	`tier2 op(_SET_IP, (instr_ptr/4 --)) {`
Original file line number	Diff line number	Diff line change
`@@ -1059,6 +1059,11 @@ prepare_for_execution(_PyUOpInstruction *buffer, int length)`
`1059`	`1059`	`buffer[i].jump_target = 0;`
`1060`	`1060`	`}`
`1061`	`1061`	`}`
	`1062`	`+ if (opcode == _JUMP_TO_TOP) {`
	`1063`	`+ assert(buffer[0].opcode == _START_EXECUTOR);`
	`1064`	`+ buffer[i].format = UOP_FORMAT_JUMP;`
	`1065`	`+ buffer[i].jump_target = 1;`
	`1066`	`+ }`
`1062`	`1067`	`}`
`1063`	`1068`	`return next_spare;`
`1064`	`1069`	`}`