Add chase and update tests

Author: jacob-shops

zjit/src/hir.rs

@@ -5068,7 +5068,7 @@ impl Function {
                 let insn_id = insns[i];
                 match self.find(insn_id) {
                     Insn::StoreField { recv, offset, .. } => {
-                        let key = StoreHeap { object: recv, offset };
+                        let key = StoreHeap { object: self.chase_insn(recv), offset };
                         // If an older store is being tracked, then there have
                         // been no usees between stores and the first store is
                         // dead.
@@ -5093,7 +5093,7 @@ impl Function {
                     // based alias analysis and the following call to prune
                     // stores is no longer used.
                     // Insn::LoadField { recv, offset, .. } => {
-                    //     let key = StoreHeap { object: recv, offset };
+                    //     let key = StoreHeap { object: self.chase_insn(recv), offset };
                     //     active_stores.remove(&key);
                     Insn::LoadField{ offset, .. } => {
                         // Because we don't have type based alias analysis, we
@@ -5102,6 +5102,15 @@ impl Function {
                         // such keys that could alias.
                         prune_stores(&mut active_stores, offset);
                     }
+                    Insn::WriteBarrier { .. } => {
+                        // Currently, WriteBarrier write effects are Allocator and Memory when we'd really like them to be flags.
+                        // We don't use LoadField for mark bits so we can ignore them for now.
+                        // But flags does not exist in our effects abstract heap modeling and we don't want to add special casing to effects.
+                        // This special casing in this pass here should be removed once we refine our effects system to provide greater granularity for WriteBarrier.
+                        // TODO: use TBAA
+                        let offset = RUBY_OFFSET_RBASIC_FLAGS;
+                        prune_stores(&mut active_stores, offset);
+                    },
                     insn => {
                         // If the instruction can read memory, we cannot assume
                         // entries of active_stores are not loaded.
@@ -5112,7 +5121,7 @@ impl Function {
 
                 }
             }
-            // TODO: Figure out if we need to handle a write barrier special case. Do these also need to be removed after removing stores?
+            // TODO: Figure out how to remove extraneous write barriers
             // Prune away any dead stores
             insns.retain(|i| !dead_stores.contains(i));
             self.blocks[block.0].insns = insns;

zjit/src/hir/opt_tests.rs

@@ -5287,14 +5287,12 @@ mod hir_opt_tests {
           v30:CShape[0x1001] = GuardBitEquals v29, CShape(0x1001)
           StoreField v28, :@foo@0x1002, v10
           WriteBarrier v28, v10
-          v33:CShape[0x1003] = Const CShape(0x1003)
-          StoreField v28, :_shape_id@0x1000, v33
           v14:HeapBasicObject = RefineType v6, HeapBasicObject
           v17:Fixnum[2] = Const Value(2)
           PatchPoint SingleRactorMode
-          StoreField v14, :@bar@0x1004, v17
+          StoreField v14, :@bar@0x1003, v17
           WriteBarrier v14, v17
-          v40:CShape[0x1005] = Const CShape(0x1005)
+          v40:CShape[0x1004] = Const CShape(0x1004)
           StoreField v14, :_shape_id@0x1000, v40
           CheckInterrupts
           Return v17
@@ -14401,21 +14399,17 @@ mod hir_opt_tests {
           v44:CShape[0x1001] = GuardBitEquals v43, CShape(0x1001)
           StoreField v42, :@a@0x1002, v10
           WriteBarrier v42, v10
-          v47:CShape[0x1003] = Const CShape(0x1003)
-          StoreField v42, :_shape_id@0x1000, v47
           v14:HeapBasicObject = RefineType v6, HeapBasicObject
           v17:Fixnum[2] = Const Value(2)
           PatchPoint SingleRactorMode
-          StoreField v14, :@b@0x1004, v17
+          StoreField v14, :@b@0x1003, v17
           WriteBarrier v14, v17
-          v54:CShape[0x1005] = Const CShape(0x1005)
-          StoreField v14, :_shape_id@0x1000, v54
           v21:HeapBasicObject = RefineType v14, HeapBasicObject
           v24:Fixnum[3] = Const Value(3)
           PatchPoint SingleRactorMode
-          StoreField v21, :@c@0x1006, v24
+          StoreField v21, :@c@0x1004, v24
           WriteBarrier v21, v24
-          v61:CShape[0x1007] = Const CShape(0x1007)
+          v61:CShape[0x1005] = Const CShape(0x1005)
           StoreField v21, :_shape_id@0x1000, v61
           v28:HeapBasicObject = RefineType v21, HeapBasicObject
           v31:Fixnum[4] = Const Value(4)
@@ -14752,21 +14746,17 @@ C.new
           v37:CShape[0x1001] = GuardBitEquals v36, CShape(0x1001)
           StoreField v35, :@a@0x1002, v10
           WriteBarrier v35, v10
-          v40:CShape[0x1003] = Const CShape(0x1003)
-          StoreField v35, :_shape_id@0x1000, v40
           v14:HeapBasicObject = RefineType v6, HeapBasicObject
           v17:Fixnum[2] = Const Value(2)
           PatchPoint SingleRactorMode
-          StoreField v14, :@b@0x1004, v17
+          StoreField v14, :@b@0x1003, v17
           WriteBarrier v14, v17
-          v47:CShape[0x1005] = Const CShape(0x1005)
-          StoreField v14, :_shape_id@0x1000, v47
           v21:HeapBasicObject = RefineType v14, HeapBasicObject
           v24:Fixnum[3] = Const Value(3)
           PatchPoint SingleRactorMode
-          StoreField v21, :@c@0x1006, v24
+          StoreField v21, :@c@0x1004, v24
           WriteBarrier v21, v24
-          v54:CShape[0x1007] = Const CShape(0x1007)
+          v54:CShape[0x1005] = Const CShape(0x1005)
           StoreField v21, :_shape_id@0x1000, v54
           CheckInterrupts
           Return v24
@@ -14842,29 +14832,22 @@ C.new
           v49:HeapBasicObject = GuardType v6, HeapBasicObject
           v50:CShape = LoadField v49, :_shape_id@0x1000
           v51:CShape[0x1001] = GuardBitEquals v50, CShape(0x1001)
-          StoreField v49, :@a@0x1002, v10
           WriteBarrier v49, v10
-          v54:CShape[0x1003] = Const CShape(0x1003)
+          v54:CShape[0x1002] = Const CShape(0x1002)
           StoreField v49, :_shape_id@0x1000, v54
           v14:HeapBasicObject = RefineType v6, HeapBasicObject
           v17:Fixnum[2] = Const Value(2)
           PatchPoint SingleRactorMode
-          StoreField v14, :@a@0x1002, v17
           WriteBarrier v14, v17
           v21:HeapBasicObject = RefineType v14, HeapBasicObject
           v24:Fixnum[3] = Const Value(3)
-          PatchPoint SingleRactorMode
-          StoreField v21, :@a@0x1002, v24
           WriteBarrier v21, v24
           v28:HeapBasicObject = RefineType v21, HeapBasicObject
           v31:Fixnum[4] = Const Value(4)
-          PatchPoint SingleRactorMode
-          StoreField v28, :@a@0x1002, v31
           WriteBarrier v28, v31
           v35:HeapBasicObject = RefineType v28, HeapBasicObject
           v38:Fixnum[5] = Const Value(5)
-          PatchPoint SingleRactorMode
-          StoreField v35, :@a@0x1002, v38
+          StoreField v35, :@a@0x1003, v38
           WriteBarrier v35, v38
           CheckInterrupts
           Return v38