DBC: Fixes typed data bugs. Adds unboxed int32 instructions

runtime/vm/simulator_dbc.cc

Index: runtime/vm/simulator_dbc.cc
diff --git a/runtime/vm/simulator_dbc.cc b/runtime/vm/simulator_dbc.cc
index ff9b6fd23251dbea459851a0579598095085914e..d66324141e32e39abd386bbcbd9394acda6aff93 100644
--- a/runtime/vm/simulator_dbc.cc
+++ b/runtime/vm/simulator_dbc.cc
@@ -249,6 +249,17 @@ class SimulatorHelpers {
     ASSERT(GetClassId(code) == kCodeCid);
     FP[kPcMarkerSlotFromFp] = code;
   }
+
+  DART_FORCE_INLINE static uint8_t* GetTypedData(
+      RawObject* obj, RawObject* index, intptr_t scale) {
+    ASSERT(RawObject::IsTypedDataClassId(obj->GetClassId()));
+    RawTypedData* array = reinterpret_cast<RawTypedData*>(obj);
+    const intptr_t byte_offset = Smi::Value(RAW_CAST(Smi, index));
+    ASSERT(byte_offset >= 0);
+    ASSERT(((byte_offset + (1 << scale)) >> scale) <=
+               Smi::Value(array->ptr()->length_));
+    return array->ptr()->data() + byte_offset;
+  }
 };
 
 
@@ -1757,10 +1768,10 @@ RawObject* Simulator::Call(const Code& code,
   }
 
   {
-    BYTECODE(ShrImm, A_B_C);
+    BYTECODE(ShlImm, A_B_C);
     const uint8_t shift = rC;
-    const intptr_t lhs = reinterpret_cast<intptr_t>(FP[rB]) >> kSmiTagSize;
-    *reinterpret_cast<intptr_t*>(&FP[rA]) = (lhs >> shift) << kSmiTagSize;
+    const intptr_t lhs = reinterpret_cast<intptr_t>(FP[rB]);
+    FP[rA] = reinterpret_cast<RawObject*>(lhs << shift);
     DISPATCH();
   }
 
@@ -1780,6 +1791,29 @@ RawObject* Simulator::Call(const Code& code,
     DISPATCH();
   }
 
+  {
+    BYTECODE(UnboxInt32, A_B_C);
+    const intptr_t box_cid = SimulatorHelpers::GetClassId(FP[rB]);
+    const bool may_truncate = rC == 1;
+    if (box_cid == kSmiCid) {
+      const intptr_t value = reinterpret_cast<intptr_t>(FP[rB]) >> kSmiTagSize;
+      const int32_t value32 = static_cast<int32_t>(value);
+      if (may_truncate || (value == static_cast<intptr_t>(value32))) {
+        FP[rA] = reinterpret_cast<RawObject*>(value);
+        pc++;
+      }
+    } else if (box_cid == kMintCid) {
+      RawMint* mint = RAW_CAST(Mint, FP[rB]);
+      const int64_t value = mint->ptr()->value_;
+      const int32_t value32 = static_cast<int32_t>(value);
+      if (may_truncate || (value == static_cast<int64_t>(value32))) {
+        FP[rA] = reinterpret_cast<RawObject*>(value);
+        pc++;
+      }
+    }
+    DISPATCH();
+  }
+
 #if defined(ARCH_IS_64_BIT)
   {
     BYTECODE(WriteIntoDouble, A_D);
@@ -1931,23 +1965,29 @@ RawObject* Simulator::Call(const Code& code,
 
   {
     BYTECODE(LoadIndexedFloat64, A_B_C);
-    ASSERT(RawObject::IsTypedDataClassId(FP[rB]->GetClassId()));
-    RawTypedData* array = reinterpret_cast<RawTypedData*>(FP[rB]);
-    RawSmi* index = RAW_CAST(Smi, FP[rC]);
-    ASSERT(SimulatorHelpers::CheckIndex(index, array->ptr()->length_));
-    double* data = reinterpret_cast<double*>(array->ptr()->data());
-    FP[rA] = bit_cast<RawObject*, double>(data[Smi::Value(index)]);
+    uint8_t* data = SimulatorHelpers::GetTypedData(FP[rB], FP[rC], 3);
+    *reinterpret_cast<uint64_t*>(&FP[rA]) = *reinterpret_cast<uint64_t*>(data);
     DISPATCH();
   }
 
   {
     BYTECODE(StoreIndexedFloat64, A_B_C);
-    ASSERT(RawObject::IsTypedDataClassId(FP[rA]->GetClassId()));
-    RawTypedData* array = reinterpret_cast<RawTypedData*>(FP[rA]);
-    RawSmi* index = RAW_CAST(Smi, FP[rB]);
-    ASSERT(SimulatorHelpers::CheckIndex(index, array->ptr()->length_));
-    double* data = reinterpret_cast<double*>(array->ptr()->data());
-    data[Smi::Value(index)] = bit_cast<double, RawObject*>(FP[rC]);
+    uint8_t* data = SimulatorHelpers::GetTypedData(FP[rA], FP[rB], 3);
+    *reinterpret_cast<uint64_t*>(data) = reinterpret_cast<uint64_t>(FP[rC]);
+    DISPATCH();
+  }
+
+  {
+    BYTECODE(BoxInt32, A_D);
+    const intptr_t value = reinterpret_cast<intptr_t>(FP[rD]);
+    FP[rA] = reinterpret_cast<RawObject*>((value << 32) >> (32 - kSmiTagSize));

[Florian Schneider, 2016/08/19 21:39:06]

Why is shifting left by 32 and right by 31 necessary? Is the upper half not
always zeroed?

[zra, 2016/08/19 22:16:04]

Both the x64 and arm64 implementations zero or sign-extend the upper bits as
appropriate. It looks like on x64, arithmetic could result in non-zero bits in
the upper half, though here and on arm64 the needed IL instructions aren't
implemented. I'll leave this as-is in case me or someone else implements those
IL instructions.

+    DISPATCH();
+  }
+
+  {
+    BYTECODE(BoxUint32, A_D);
+    const uintptr_t value = reinterpret_cast<uintptr_t>(FP[rD]);
+    FP[rA] = reinterpret_cast<RawObject*>((value << 32) >> (32 - kSmiTagSize));

[Florian Schneider, 2016/08/19 21:39:05]

Maybe add a local helper SmiTagInt32(intptr_t value)?

[zra, 2016/08/19 22:16:04]

Decided to do casting instead of shifting.

     DISPATCH();
   }
 #else  // defined(ARCH_IS_64_BIT)
@@ -2064,6 +2104,18 @@ RawObject* Simulator::Call(const Code& code,
     UNREACHABLE();
     DISPATCH();
   }
+
+  {
+    BYTECODE(BoxInt32, A_D);
+    UNREACHABLE();
+    DISPATCH();
+  }
+
+  {
+    BYTECODE(BoxUint32, A_D);
+    UNREACHABLE();
+    DISPATCH();
+  }
 #endif  // defined(ARCH_IS_64_BIT)
 
   // Return and return like instructions (Instrinsic).
@@ -2854,13 +2906,8 @@ RawObject* Simulator::Call(const Code& code,
 
   {
     BYTECODE(StoreIndexedUint8, A_B_C);
-    ASSERT(RawObject::IsTypedDataClassId(FP[rA]->GetClassId()));
-    RawTypedData* array = reinterpret_cast<RawTypedData*>(FP[rA]);
-    RawSmi* index = RAW_CAST(Smi, FP[rB]);
-    RawSmi* value = RAW_CAST(Smi, FP[rC]);
-    ASSERT(SimulatorHelpers::CheckIndex(index, array->ptr()->length_));
-    uint8_t* data = reinterpret_cast<uint8_t*>(array->ptr()->data());
-    data[Smi::Value(index)] = static_cast<uint8_t>(Smi::Value(value));
+    uint8_t* data = SimulatorHelpers::GetTypedData(FP[rA], FP[rB], 0);
+    *data = static_cast<uint8_t>(Smi::Value(RAW_CAST(Smi, FP[rC])));
     DISPATCH();
   }
 
@@ -2874,6 +2921,14 @@ RawObject* Simulator::Call(const Code& code,
   }
 
   {
+    BYTECODE(StoreIndexedUint32, A_B_C);
+    uint8_t* data = SimulatorHelpers::GetTypedData(FP[rA], FP[rB], 2);
+    const uintptr_t value = reinterpret_cast<uintptr_t>(FP[rC]);
+    *reinterpret_cast<uint32_t*>(data) = static_cast<uint32_t>(value);
+    DISPATCH();
+  }
+
+  {
     BYTECODE(LoadIndexed, A_B_C);
     RawArray* array = RAW_CAST(Array, FP[rB]);
     RawSmi* index = RAW_CAST(Smi, FP[rC]);
@@ -2884,23 +2939,29 @@ RawObject* Simulator::Call(const Code& code,
 
   {
     BYTECODE(LoadIndexedUint8, A_B_C);
-    ASSERT(RawObject::IsTypedDataClassId(FP[rB]->GetClassId()));
-    RawTypedData* array = reinterpret_cast<RawTypedData*>(FP[rB]);
-    RawSmi* index = RAW_CAST(Smi, FP[rC]);
-    ASSERT(SimulatorHelpers::CheckIndex(index, array->ptr()->length_));
-    uint8_t* data = reinterpret_cast<uint8_t*>(array->ptr()->data());
-    FP[rA] = Smi::New(data[Smi::Value(index)]);
+    uint8_t* data = SimulatorHelpers::GetTypedData(FP[rB], FP[rC], 0);
+    FP[rA] = Smi::New(*data);
     DISPATCH();
   }
 
   {
     BYTECODE(LoadIndexedInt8, A_B_C);
-    ASSERT(RawObject::IsTypedDataClassId(FP[rB]->GetClassId()));
-    RawTypedData* array = reinterpret_cast<RawTypedData*>(FP[rB]);
-    RawSmi* index = RAW_CAST(Smi, FP[rC]);
-    ASSERT(SimulatorHelpers::CheckIndex(index, array->ptr()->length_));
-    int8_t* data = reinterpret_cast<int8_t*>(array->ptr()->data());
-    FP[rA] = Smi::New(data[Smi::Value(index)]);
+    uint8_t* data = SimulatorHelpers::GetTypedData(FP[rB], FP[rC], 0);
+    FP[rA] = Smi::New(*reinterpret_cast<int8_t*>(data));
+    DISPATCH();
+  }
+
+  {
+    BYTECODE(LoadIndexedUint32, A_B_C);
+    uint8_t* data = SimulatorHelpers::GetTypedData(FP[rB], FP[rC], 2);
+    FP[rA] = reinterpret_cast<RawObject*>(*reinterpret_cast<uintptr_t*>(data));
+    DISPATCH();
+  }
+
+  {
+    BYTECODE(LoadIndexedInt32, A_B_C);
+    uint8_t* data = SimulatorHelpers::GetTypedData(FP[rB], FP[rC], 2);
+    FP[rA] = reinterpret_cast<RawObject*>(*reinterpret_cast<intptr_t*>(data));
     DISPATCH();
   }