ZJIT: Add reason for SideExit (#13768)

This makes it clearer what is unimplemented when looking at HIR dumps.

3 files changed, 53 insertions, 28 deletions

diff --git a/zjit/src/codegen.rs b/zjit/src/codegen.rs
index 6d73a3a32d..9fa088c0d1 100644
--- a/zjit/src/codegen.rs
+++ b/zjit/src/codegen.rs
@@ -287,7 +287,7 @@ fn gen_insn(cb: &mut CodeBlock, jit: &mut JITState, asm: &mut Assembler, functio
         Insn::SetLocal { val, ep_offset, level } => return gen_nested_setlocal(asm, opnd!(val), *ep_offset, *level),
         Insn::GetConstantPath { ic, state } => gen_get_constant_path(asm, *ic, &function.frame_state(*state)),
         Insn::SetIvar { self_val, id, val, state: _ } => return gen_setivar(asm, opnd!(self_val), *id, opnd!(val)),
-        Insn::SideExit { state } => return gen_side_exit(jit, asm, &function.frame_state(*state)),
+        Insn::SideExit { state, reason: _ } => return gen_side_exit(jit, asm, &function.frame_state(*state)),
         Insn::PutSpecialObject { value_type } => gen_putspecialobject(asm, *value_type),
         Insn::AnyToString { val, str, state } => gen_anytostring(asm, opnd!(val), opnd!(str), &function.frame_state(*state))?,
         Insn::Defined { op_type, obj, pushval, v } => gen_defined(jit, asm, *op_type, *obj, *pushval, opnd!(v))?,
diff --git a/zjit/src/cruby.rs b/zjit/src/cruby.rs
index e5b66be850..82f0e39804 100644
--- a/zjit/src/cruby.rs
+++ b/zjit/src/cruby.rs
@@ -218,6 +218,9 @@ pub use rb_vm_get_special_object as vm_get_special_object;
 
 /// Helper so we can get a Rust string for insn_name()
 pub fn insn_name(opcode: usize) -> String {
+    if opcode >= VM_INSTRUCTION_SIZE.try_into().unwrap() {
+        return "<unknown>".into();
+    }
     unsafe {
         // Look up Ruby's NULL-terminated insn name string
         let op_name = raw_insn_name(VALUE(opcode));
diff --git a/zjit/src/hir.rs b/zjit/src/hir.rs
index 30a6da201e..be320f6d74 100644
--- a/zjit/src/hir.rs
+++ b/zjit/src/hir.rs
@@ -393,6 +393,28 @@ impl PtrPrintMap {
     }
 }
 
+#[derive(Debug, Clone)]
+pub enum SideExitReason {
+    UnknownNewarraySend(vm_opt_newarray_send_type),
+    UnknownCallType,
+    UnknownOpcode(u32),
+}
+
+impl std::fmt::Display for SideExitReason {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        match self {
+            SideExitReason::UnknownOpcode(opcode) => write!(f, "UnknownOpcode({})", insn_name(*opcode as usize)),
+            SideExitReason::UnknownNewarraySend(VM_OPT_NEWARRAY_SEND_MAX) => write!(f, "UnknownNewarraySend(MAX)"),
+            SideExitReason::UnknownNewarraySend(VM_OPT_NEWARRAY_SEND_MIN) => write!(f, "UnknownNewarraySend(MIN)"),
+            SideExitReason::UnknownNewarraySend(VM_OPT_NEWARRAY_SEND_HASH) => write!(f, "UnknownNewarraySend(HASH)"),
+            SideExitReason::UnknownNewarraySend(VM_OPT_NEWARRAY_SEND_PACK) => write!(f, "UnknownNewarraySend(PACK)"),
+            SideExitReason::UnknownNewarraySend(VM_OPT_NEWARRAY_SEND_PACK_BUFFER) => write!(f, "UnknownNewarraySend(PACK_BUFFER)"),
+            SideExitReason::UnknownNewarraySend(VM_OPT_NEWARRAY_SEND_INCLUDE_P) => write!(f, "UnknownNewarraySend(INCLUDE_P)"),
+            _ => write!(f, "{self:?}"),
+        }
+    }
+}
+
 /// An instruction in the SSA IR. The output of an instruction is referred to by the index of
 /// the instruction ([`InsnId`]). SSA form enables this, and [`UnionFind`] ([`Function::find`])
 /// helps with editing.
@@ -518,7 +540,7 @@ pub enum Insn {
     PatchPoint(Invariant),
 
     /// Side-exit into the interpreter.
-    SideExit { state: InsnId },
+    SideExit { state: InsnId, reason: SideExitReason },
 }
 
 impl Insn {
@@ -714,7 +736,7 @@ impl<'a> std::fmt::Display for InsnPrinter<'a> {
             Insn::ArrayPush { array, val, .. } => write!(f, "ArrayPush {array}, {val}"),
             Insn::ObjToString { val, .. } => { write!(f, "ObjToString {val}") },
             Insn::AnyToString { val, str, .. } => { write!(f, "AnyToString {val}, str: {str}") },
-            Insn::SideExit { .. } => write!(f, "SideExit"),
+            Insn::SideExit { reason, .. } => write!(f, "SideExit {reason}"),
             Insn::PutSpecialObject { value_type } => write!(f, "PutSpecialObject {value_type}"),
             Insn::Throw { throw_state, val } => {
                 let mut state_string = match throw_state & VM_THROW_STATE_MASK {
@@ -1863,7 +1885,7 @@ impl Function {
                     worklist.push_back(state);
                 }
                 Insn::GetGlobal { state, .. } |
-                Insn::SideExit { state } => worklist.push_back(state),
+                Insn::SideExit { state, .. } => worklist.push_back(state),
             }
         }
         // Now remove all unnecessary instructions
@@ -2425,7 +2447,7 @@ pub fn iseq_to_hir(iseq: *const rb_iseq_t) -> Result<Function, ParseError> {
                         VM_OPT_NEWARRAY_SEND_MAX => (BOP_MAX, Insn::ArrayMax { elements, state: exit_id }),
                         _ => {
                             // Unknown opcode; side-exit into the interpreter
-                            fun.push_insn(block, Insn::SideExit { state: exit_id });
+                            fun.push_insn(block, Insn::SideExit { state: exit_id, reason: SideExitReason::UnknownNewarraySend(method) });
                             break;  // End the block
                         },
                     };
@@ -2651,7 +2673,7 @@ pub fn iseq_to_hir(iseq: *const rb_iseq_t) -> Result<Function, ParseError> {
                     if unknown_call_type(unsafe { rb_vm_ci_flag(call_info) }) {
                         // Unknown call type; side-exit into the interpreter
                         let exit_id = fun.push_insn(block, Insn::Snapshot { state: exit_state });
-                        fun.push_insn(block, Insn::SideExit { state: exit_id });
+                        fun.push_insn(block, Insn::SideExit { state: exit_id, reason: SideExitReason::UnknownCallType });
                         break;  // End the block
                     }
                     let argc = unsafe { vm_ci_argc((*cd).ci) };
@@ -2677,7 +2699,7 @@ pub fn iseq_to_hir(iseq: *const rb_iseq_t) -> Result<Function, ParseError> {
                     if unknown_call_type(unsafe { rb_vm_ci_flag(call_info) }) {
                         // Unknown call type; side-exit into the interpreter
                         let exit_id = fun.push_insn(block, Insn::Snapshot { state: exit_state });
-                        fun.push_insn(block, Insn::SideExit { state: exit_id });
+                        fun.push_insn(block, Insn::SideExit { state: exit_id, reason: SideExitReason::UnknownCallType });
                         break;  // End the block
                     }
                     let argc = unsafe { vm_ci_argc((*cd).ci) };
@@ -2708,7 +2730,7 @@ pub fn iseq_to_hir(iseq: *const rb_iseq_t) -> Result<Function, ParseError> {
                     if unknown_call_type(unsafe { rb_vm_ci_flag(call_info) }) {
                         // Unknown call type; side-exit into the interpreter
                         let exit_id = fun.push_insn(block, Insn::Snapshot { state: exit_state });
-                        fun.push_insn(block, Insn::SideExit { state: exit_id });
+                        fun.push_insn(block, Insn::SideExit { state: exit_id, reason: SideExitReason::UnknownCallType });
                         break;  // End the block
                     }
                     let argc = unsafe { vm_ci_argc((*cd).ci) };
@@ -2768,7 +2790,7 @@ pub fn iseq_to_hir(iseq: *const rb_iseq_t) -> Result<Function, ParseError> {
                     if unknown_call_type(unsafe { rb_vm_ci_flag(call_info) }) {
                         // Unknown call type; side-exit into the interpreter
                         let exit_id = fun.push_insn(block, Insn::Snapshot { state: exit_state });
-                        fun.push_insn(block, Insn::SideExit { state: exit_id });
+                        fun.push_insn(block, Insn::SideExit { state: exit_id, reason: SideExitReason::UnknownCallType });
                         break;  // End the block
                     }
                     let argc = unsafe { vm_ci_argc((*cd).ci) };
@@ -2796,7 +2818,7 @@ pub fn iseq_to_hir(iseq: *const rb_iseq_t) -> Result<Function, ParseError> {
                     if unknown_call_type(unsafe { rb_vm_ci_flag(call_info) }) {
                         // Unknown call type; side-exit into the interpreter
                         let exit_id = fun.push_insn(block, Insn::Snapshot { state: exit_state });
-                        fun.push_insn(block, Insn::SideExit { state: exit_id });
+                        fun.push_insn(block, Insn::SideExit { state: exit_id, reason: SideExitReason::UnknownCallType });
                         break;  // End the block
                     }
                     let argc = unsafe { vm_ci_argc((*cd).ci) };
@@ -2920,7 +2942,7 @@ pub fn iseq_to_hir(iseq: *const rb_iseq_t) -> Result<Function, ParseError> {
                 _ => {
                     // Unknown opcode; side-exit into the interpreter
                     let exit_id = fun.push_insn(block, Insn::Snapshot { state: exit_state });
-                    fun.push_insn(block, Insn::SideExit { state: exit_id });
+                    fun.push_insn(block, Insn::SideExit { state: exit_id, reason: SideExitReason::UnknownOpcode(opcode) });
                     break;  // End the block
                 }
             }
@@ -3962,7 +3984,7 @@ mod tests {
             fn test:
             bb0(v0:BasicObject, v1:BasicObject):
               v4:ArrayExact = ToArray v1
-              SideExit
+              SideExit UnknownCallType
         "#]]);
     }
 
@@ -3974,7 +3996,7 @@ mod tests {
         assert_method_hir("test",  expect![[r#"
             fn test:
             bb0(v0:BasicObject, v1:BasicObject):
-              SideExit
+              SideExit UnknownCallType
         "#]]);
     }
 
@@ -3987,7 +4009,7 @@ mod tests {
             fn test:
             bb0(v0:BasicObject, v1:BasicObject):
               v3:Fixnum[1] = Const Value(1)
-              SideExit
+              SideExit UnknownCallType
         "#]]);
     }
 
@@ -3999,7 +4021,7 @@ mod tests {
         assert_method_hir("test",  expect![[r#"
             fn test:
             bb0(v0:BasicObject, v1:BasicObject):
-              SideExit
+              SideExit UnknownCallType
         "#]]);
     }
 
@@ -4013,7 +4035,7 @@ mod tests {
         assert_method_hir("test",  expect![[r#"
             fn test:
             bb0(v0:BasicObject):
-              SideExit
+              SideExit UnknownOpcode(invokesuper)
         "#]]);
     }
 
@@ -4025,7 +4047,7 @@ mod tests {
         assert_method_hir("test",  expect![[r#"
             fn test:
             bb0(v0:BasicObject):
-              SideExit
+              SideExit UnknownOpcode(invokesuper)
         "#]]);
     }
 
@@ -4037,7 +4059,7 @@ mod tests {
         assert_method_hir("test",  expect![[r#"
             fn test:
             bb0(v0:BasicObject, v1:BasicObject):
-              SideExit
+              SideExit UnknownOpcode(invokesuperforward)
         "#]]);
     }
 
@@ -4058,7 +4080,7 @@ mod tests {
               v9:StaticSymbol[:b] = Const Value(VALUE(0x1008))
               v10:Fixnum[1] = Const Value(1)
               v12:BasicObject = SendWithoutBlock v8, :core#hash_merge_ptr, v7, v9, v10
-              SideExit
+              SideExit UnknownCallType
         "#]]);
     }
 
@@ -4073,7 +4095,7 @@ mod tests {
               v4:ArrayExact = ToNewArray v1
               v5:Fixnum[1] = Const Value(1)
               ArrayPush v4, v5
-              SideExit
+              SideExit UnknownCallType
         "#]]);
     }
 
@@ -4085,7 +4107,7 @@ mod tests {
         assert_method_hir("test",  expect![[r#"
             fn test:
             bb0(v0:BasicObject, v1:BasicObject):
-              SideExit
+              SideExit UnknownOpcode(sendforward)
         "#]]);
     }
 
@@ -4154,7 +4176,7 @@ mod tests {
               v3:NilClassExact = Const Value(nil)
               v4:NilClassExact = Const Value(nil)
               v7:BasicObject = SendWithoutBlock v1, :+, v2
-              SideExit
+              SideExit UnknownNewarraySend(MIN)
         "#]]);
     }
 
@@ -4174,7 +4196,7 @@ mod tests {
               v3:NilClassExact = Const Value(nil)
               v4:NilClassExact = Const Value(nil)
               v7:BasicObject = SendWithoutBlock v1, :+, v2
-              SideExit
+              SideExit UnknownNewarraySend(HASH)
         "#]]);
     }
 
@@ -4196,7 +4218,7 @@ mod tests {
               v7:BasicObject = SendWithoutBlock v1, :+, v2
               v8:StringExact[VALUE(0x1000)] = Const Value(VALUE(0x1000))
               v9:StringExact = StringCopy v8
-              SideExit
+              SideExit UnknownNewarraySend(PACK)
         "#]]);
     }
 
@@ -4218,7 +4240,7 @@ mod tests {
               v3:NilClassExact = Const Value(nil)
               v4:NilClassExact = Const Value(nil)
               v7:BasicObject = SendWithoutBlock v1, :+, v2
-              SideExit
+              SideExit UnknownNewarraySend(INCLUDE_P)
         "#]]);
     }
 
@@ -4642,7 +4664,7 @@ mod tests {
               v3:Fixnum[1] = Const Value(1)
               v5:BasicObject = ObjToString v3
               v7:String = AnyToString v3, str: v5
-              SideExit
+              SideExit UnknownOpcode(concatstrings)
         "#]]);
     }
 
@@ -6220,7 +6242,7 @@ mod opt_tests {
               v2:StringExact[VALUE(0x1000)] = Const Value(VALUE(0x1000))
               v3:StringExact[VALUE(0x1008)] = Const Value(VALUE(0x1008))
               v4:StringExact = StringCopy v3
-              SideExit
+              SideExit UnknownOpcode(concatstrings)
         "#]]);
     }
 
@@ -6236,7 +6258,7 @@ mod opt_tests {
               v3:Fixnum[1] = Const Value(1)
               v10:BasicObject = SendWithoutBlock v3, :to_s
               v7:String = AnyToString v3, str: v10
-              SideExit
+              SideExit UnknownOpcode(concatstrings)
         "#]]);
     }