Revert D98315856: Don't generate Decrefs for immortal types

Differential Revision:
D98315856

Original commit changeset: 291bd19916bf

Original Phabricator Diff: D98315856

fbshipit-source-id: 46da0a1ecd8bb34fb060bfffe0ad88168b1394d1

Author: phouri

cinderx/Jit/hir/refcount_insertion.cpp

@@ -476,14 +476,7 @@ std::vector<PredState> collectPredStates(Env& env, BasicBlock* block) {
 // Return true iff the given Register is definitely not a reference-counted
 // value.
 bool isUncounted(const Register* reg) {
-  auto ty = reg->type();
-  if (!ty.couldBe(TMortalObject)) {
-    return true;
-  }
-
-  // Types like TMortalBool always exist in the type system but with immortal
-  // instances enabled they're identical to their immortal equivalents.
-  return kImmortalInstances && (ty <= (TNoneType | TBool));
+  return !reg->type().couldBe(TMortalObject);
 }
 
 // Insert an Incref of `reg` before `cursor`.

cinderx/RuntimeTests/hir_guard_test.cpp

@@ -165,26 +165,26 @@ fun __main__:test {
     }
     v1:NoneType = LoadConst<NoneType>
     v2:Object = LoadGlobal<0> {
-      LiveValues<2> b:v0 unc:v1
+      LiveValues<2> b:v0 b:v1
       FrameState {
         CurInstrOffset -2
       }
     }
     CheckExc v2 {
-      LiveValues<3> b:v0 unc:v1 o:v2
+      LiveValues<3> b:v0 b:v1 o:v2
       FrameState {
         CurInstrOffset 6
       }
     }
     Guard v2 {
-      LiveValues<3> b:v0 unc:v1 o:v2
+      LiveValues<3> b:v0 b:v1 o:v2
       FrameState {
         CurInstrOffset 6
         Stack<3> v0 v1 v2
       }
     }
     v3:Object = VectorCall<2> v0 v1 v2 {
-      LiveValues<3> b:v0 unc:v1 o:v2
+      LiveValues<3> b:v0 b:v1 o:v2
       FrameState {
         CurInstrOffset -2
       }

cinderx/RuntimeTests/hir_tests/all_passes_static_test.txt

@@ -89,6 +89,7 @@ fun jittestmodule:test {
   bb 3 (preds 1) {
     XDecref v25
     v44:NoneType = LoadConst<NoneType>
+    Incref v44
     Return v44
   }
 }

cinderx/RuntimeTests/hir_tests/all_passes_test.txt

@@ -980,6 +980,7 @@ fun jittestmodule:test {
     }
     Decref v8
     v15:NoneType = LoadConst<NoneType>
+    Incref v15
     Return v15
   }
 }

cinderx/RuntimeTests/hir_tests/refcount_insertion_static_test.txt

@@ -20,6 +20,7 @@ fun jittestmodule:Test.__init__ {
     v8:Nullptr = LoadConst<Nullptr>
     StoreField<x@16> v5 v6 v8
     v10:NoneType = LoadConst<NoneType>
+    Incref v10
     Return<NoneType> v10
   }
 }
@@ -124,6 +125,7 @@ fun jittestmodule:Test.__init__ {
     StoreField<x@16> v4 v5 v7
     XDecref v7
     v8:NoneType = LoadConst<NoneType>
+    Incref v8
     Return<NoneType> v8
   }
 }

cinderx/RuntimeTests/hir_tests/refcount_insertion_test.txt

@@ -931,6 +931,7 @@ fun jittestmodule:test {
     Decref v44
     Decref v47
     v48:NoneType = LoadConst<NoneType>
+    Incref v48
     Return v48
   }
 }
@@ -1406,6 +1407,7 @@ fun jittestmodule:test {
     Decref v54
     Decref v57
     v58:NoneType = LoadConst<NoneType>
+    Incref v58
     Return v58
   }
 }
@@ -1949,6 +1951,7 @@ fun jittestmodule:test {
     Decref v25
     XDecref v26
     v42:NoneType = LoadConst<NoneType>
+    Incref v42
     Return v42
   }
 }
@@ -2358,6 +2361,7 @@ fun jittestmodule:test {
       }
     }
     v7:NoneType = LoadConst<NoneType>
+    Incref v7
     Return v7
   }
 }
@@ -3351,12 +3355,14 @@ fun jittestmodule:test {
     Decref v32
     Decref v33
     v34:NoneType = LoadConst<NoneType>
+    Incref v34
     Return v34
   }
 
   bb 6 (preds 4) {
     XDecref v27
     v35:NoneType = LoadConst<NoneType>
+    Incref v35
     Return v35
   }
 }
@@ -3824,6 +3830,7 @@ fun jittestmodule:test {
 
   bb 3 (preds 2) {
     v39:NoneType = LoadConst<NoneType>
+    Incref v39
     Branch<4>
   }
 
@@ -3839,7 +3846,7 @@ fun jittestmodule:test {
     v47:OptObject = LoadGlobalCached<1; "print">
     v48:MortalObjectUser[builtin_function_or_method:print:0xdeadbeef] = GuardIs<0xdeadbeef> v47 {
       Descr 'LOAD_GLOBAL: print'
-      LiveValues<6> b:v17 b:v27 o:v42 o:v44 unc:v45 b:v47
+      LiveValues<6> b:v17 b:v27 o:v42 o:v44 b:v45 b:v47
       FrameState {
         CurInstrOffset 34
         Locals<4> v27 v42 v17 v44
@@ -3848,7 +3855,7 @@ fun jittestmodule:test {
     Incref v27
     Decref v42
     v50:Object = VectorCall<1> v48 v27 {
-      LiveValues<5> b:v17 o:v27 o:v44 unc:v45 b:v48
+      LiveValues<5> b:v17 o:v27 o:v44 b:v45 b:v48
       FrameState {
         CurInstrOffset 42
         Locals<4> v27 v45 v17 v44
@@ -3858,6 +3865,7 @@ fun jittestmodule:test {
     Decref v44
     Decref v50
     v51:NoneType = LoadConst<NoneType>
+    Incref v51
     Return v51
   }
 }
@@ -4277,6 +4285,7 @@ fun jittestmodule:test {
     }
     Decref v11
     v14:NoneType = LoadConst<NoneType>
+    Incref v14
     Return v14
   }
 }
@@ -4298,6 +4307,7 @@ fun jittestmodule:test {
     }
     Decref v11
     v14:NoneType = LoadConst<NoneType>
+    Incref v14
     Return v14
   }
 }
@@ -4319,6 +4329,7 @@ fun jittestmodule:test {
     }
     Decref v11
     v14:NoneType = LoadConst<NoneType>
+    Incref v14
     Return v14
   }
 }
@@ -4340,6 +4351,7 @@ fun jittestmodule:test {
     }
     Decref v11
     v14:NoneType = LoadConst<NoneType>
+    Incref v14
     Return v14
   }
 }