Fix StoreIndexedInstr input representation requirements for Int32/Uint32 arrays.

runtime/vm/intermediate_language_arm64.cc

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_ARM64.
 #if defined(TARGET_ARCH_ARM64)
 
 #include "vm/intermediate_language.h"
 
 #include "vm/dart_entry.h"
@@ skipping 270 matching lines @@
   if (!locs()->out(0).IsInvalid()) {
     const Register result = locs()->out(0).reg();
     __ LoadObject(result, value(), PP);
   }
 }
 
 
 LocationSummary* UnboxedConstantInstr::MakeLocationSummary(Isolate* isolate,
                                                            bool opt) const {
   const intptr_t kNumInputs = 0;
+  const Location out = (representation_ == kUnboxedInt32) ?
+      Location::RequiresRegister() : Location::RequiresFpuRegister();
   return LocationSummary::Make(isolate,
                                kNumInputs,
-                               Location::RequiresFpuRegister(),
+                               out,
                                LocationSummary::kNoCall);
 }
 
 
 void UnboxedConstantInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
-  ASSERT(representation_ == kUnboxedDouble);
   if (!locs()->out(0).IsInvalid()) {
-    if (Utils::DoublesBitEqual(Double::Cast(value()).value(), 0.0)) {
-      const VRegister dst = locs()->out(0).fpu_reg();
-      __ veor(dst, dst, dst);
-    } else {
-      const VRegister dst = locs()->out(0).fpu_reg();
-      __ LoadDImmediate(dst, Double::Cast(value()).value(), PP);
+    switch (representation_) {
+      case kUnboxedDouble:
+        if (Utils::DoublesBitEqual(Double::Cast(value()).value(), 0.0)) {
+          const VRegister dst = locs()->out(0).fpu_reg();
+          __ veor(dst, dst, dst);
+        } else {
+          const VRegister dst = locs()->out(0).fpu_reg();
+          __ LoadDImmediate(dst, Double::Cast(value()).value(), PP);
+        }
+        break;
+      case kUnboxedInt32:
+        __ LoadImmediate(locs()->out(0).reg(),
+                         static_cast<int32_t>(Smi::Cast(value()).Value()),
+                         PP);
+        break;
+      default:
+        UNREACHABLE();
+        break;
     }
   }
 }
 
 
 LocationSummary* AssertAssignableInstr::MakeLocationSummary(Isolate* isolate,
                                                             bool opt) const {
   const intptr_t kNumInputs = 3;
   const intptr_t kNumTemps = 0;
   LocationSummary* summary = new(isolate) LocationSummary(
@@ skipping 806 matching lines @@
   switch (class_id_) {
     case kArrayCid:
     case kOneByteStringCid:
     case kTypedDataInt8ArrayCid:
     case kTypedDataUint8ArrayCid:
     case kExternalTypedDataUint8ArrayCid:
     case kTypedDataUint8ClampedArrayCid:
     case kExternalTypedDataUint8ClampedArrayCid:
     case kTypedDataInt16ArrayCid:
     case kTypedDataUint16ArrayCid:
+      return kTagged;
     case kTypedDataInt32ArrayCid:
+      return kUnboxedInt32;
     case kTypedDataUint32ArrayCid:
-      return kTagged;
+      return kUnboxedUint32;
     case kTypedDataFloat32ArrayCid:
     case kTypedDataFloat64ArrayCid:
       return kUnboxedDouble;
     case kTypedDataFloat32x4ArrayCid:
       return kUnboxedFloat32x4;
     case kTypedDataInt32x4ArrayCid:
       return kUnboxedInt32x4;
     case kTypedDataFloat64x2ArrayCid:
       return kUnboxedFloat64x2;
     default:
@@ skipping 118 matching lines @@
     case kTypedDataInt16ArrayCid:
     case kTypedDataUint16ArrayCid: {
       const Register value = locs()->in(2).reg();
       __ SmiUntag(TMP, value);
       __ str(TMP, element_address, kUnsignedHalfword);
       break;
     }
     case kTypedDataInt32ArrayCid:
     case kTypedDataUint32ArrayCid: {
       const Register value = locs()->in(2).reg();
-      __ SmiUntag(TMP, value);
-      __ str(TMP, element_address, kUnsignedWord);
+      __ str(value, element_address, kUnsignedWord);
       break;
     }
     case kTypedDataFloat32ArrayCid: {
       const VRegister value_reg = locs()->in(2).fpu_reg();
       __ fstrs(value_reg, element_address);
       break;
     }
     case kTypedDataFloat64ArrayCid: {
       const VRegister value_reg = locs()->in(2).fpu_reg();
       __ fstrd(value_reg, element_address);
@@ skipping 3864 matching lines @@
 
 
 CompileType UnaryUint32OpInstr::ComputeType() const {
   return CompileType::FromCid(kSmiCid);
 }
 
 
 DEFINE_UNIMPLEMENTED_INSTRUCTION(BinaryUint32OpInstr)
 DEFINE_UNIMPLEMENTED_INSTRUCTION(ShiftUint32OpInstr)
 DEFINE_UNIMPLEMENTED_INSTRUCTION(UnaryUint32OpInstr)
-DEFINE_UNIMPLEMENTED_INSTRUCTION(BoxInt32Instr)
-DEFINE_UNIMPLEMENTED_INSTRUCTION(UnboxInt32Instr)
 DEFINE_UNIMPLEMENTED_INSTRUCTION(BinaryInt32OpInstr)
-DEFINE_UNIMPLEMENTED_INSTRUCTION(BoxUint32Instr)
-DEFINE_UNIMPLEMENTED_INSTRUCTION(UnboxedIntConverterInstr)
 
 
-LocationSummary* UnboxUint32Instr::MakeLocationSummary(Isolate* isolate,
+LocationSummary* UnboxIntNInstr::MakeLocationSummary(Isolate* isolate,
                                                        bool opt) const {
   const intptr_t kNumInputs = 1;
   const intptr_t kNumTemps = 0;
   LocationSummary* summary = new(isolate) LocationSummary(
       isolate, kNumInputs, kNumTemps, LocationSummary::kNoCall);
   summary->set_in(0, Location::RequiresRegister());
-  summary->set_out(0, Location::SameAsFirstInput());
+  summary->set_out(0, Location::RequiresRegister());
   return summary;
 }
 
 
-void UnboxUint32Instr::EmitNativeCode(FlowGraphCompiler* compiler) {
+void UnboxIntNInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   const intptr_t value_cid = value()->Type()->ToCid();
+  const Register out = locs()->out(0).reg();
   const Register value = locs()->in(0).reg();
-  ASSERT(value == locs()->out(0).reg());
+  Label* deopt = CanDeoptimize() ?
+      compiler->AddDeoptStub(deopt_id_, ICData::kDeoptUnboxInteger) : NULL;
 
   if (value_cid == kSmiCid) {
-    __ SmiUntag(value);
+    __ SmiUntag(out, value);
+  } else if (value_cid == kMintCid) {
+    __ LoadFieldFromOffset(out, value, Mint::value_offset(), PP);
   } else {
-    Label* deopt = compiler->AddDeoptStub(deopt_id_,
-                                          ICData::kDeoptUnboxInteger);
-    __ tsti(value, kSmiTagMask);
+    Label done;
+    __ SmiUntag(out, value);
+    __ TestImmediate(value, kSmiTagMask, PP);
+    __ b(&done, EQ);
+    __ CompareClassId(value, kMintCid, PP);
     __ b(deopt, NE);
-    __ SmiUntag(value);
+    __ LoadFieldFromOffset(out, value, Mint::value_offset(), PP);
+    __ Bind(&done);
+  }
+
+  // TODO(vegorov): as it is implemented right now truncating unboxing would
+  // leave "garbage" in the higher word.
+  if (!is_truncating() && (deopt != NULL)) {
+    ASSERT(representation() == kUnboxedInt32);
+    __ cmp(out, Operand(out, SXTW, 0));

[zra, 2014/09/10 23:17:22]

Not sure if this helps you any, but if you specify the size in
LoadFieldFromOffset, i.e. LoadFieldFromOffset(..., PP, {kWord, kUnsignedWord}),
it will read 32 bits and then sign extend into the result register, always
extending 0's for kUnsignedWord no matter what the top bit is.

[Vyacheslav Egorov (Google), 2014/09/11 11:49:17]

I am doing int64 -> int32 convertion here. What I want to check is that this
conversion is lossless, e.g. that value was 32-bit signed value to begin with.
Essentially I am doing:

static_cast<int64_t>(static_cast<int32_t>(v)) == v

So I can't load it as a Word in !is_truncating() case. I could load it as a word
in is_truncating() case, but I decided against that for uniformity for now.

+    __ b(deopt, NE);
   }
 }
 
+
+LocationSummary* BoxIntNInstr::MakeLocationSummary(Isolate* isolate,
+                                                   bool opt) const {
+  ASSERT((from_representation() == kUnboxedInt32) ||
+         (from_representation() == kUnboxedUint32));
+  const intptr_t kNumInputs = 1;
+  const intptr_t kNumTemps = 0;
+  LocationSummary* summary = new(isolate) LocationSummary(
+      isolate,
+      kNumInputs,
+      kNumTemps,
+      LocationSummary::kNoCall);
+  summary->set_in(0, Location::RequiresRegister());
+  summary->set_out(0, Location::RequiresRegister());
+  return summary;
+}
+
+
+void BoxIntNInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
+  Register value = locs()->in(0).reg();
+  Register out = locs()->out(0).reg();
+  ASSERT(value != out);
+
+  ASSERT(kSmiTagSize == 1);
+  // TODO(vegorov) implement and use UBFM/SBFM for this.
+  __ Lsl(out, value, 32);
+  if (from_representation() == kUnboxedInt32) {
+    __ Asr(out, out, 32 - kSmiTagSize);
+  } else {
+    ASSERT(from_representation() == kUnboxedUint32);
+    __ Lsr(out, out, 32 - kSmiTagSize);
+  }
+}
+
+
+LocationSummary* UnboxedIntConverterInstr::MakeLocationSummary(Isolate* isolate,
+                                                               bool opt) const {
+  const intptr_t kNumInputs = 1;
+  const intptr_t kNumTemps = 0;
+  LocationSummary* summary = new(isolate) LocationSummary(
+      isolate, kNumInputs, kNumTemps, LocationSummary::kNoCall);
+  if (from() == kUnboxedMint) {
+    UNREACHABLE();
+  } else if (to() == kUnboxedMint) {
+    UNREACHABLE();
+  } else {
+    ASSERT((to() == kUnboxedUint32) || (to() == kUnboxedInt32));
+    ASSERT((from() == kUnboxedUint32) || (from() == kUnboxedInt32));
+    summary->set_in(0, Location::RequiresRegister());
+    summary->set_out(0, Location::RequiresRegister());
+  }
+  return summary;
+}
+
+
+void UnboxedIntConverterInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
+  if (from() == kUnboxedInt32 && to() == kUnboxedUint32) {
+    const Register value = locs()->in(0).reg();
+    const Register out = locs()->out(0).reg();
+    // Representations are bitwise equivalent but we want to normalize
+    // upperbits for safety reasons.
+    // TODO(vegorov) if we ensure that we never use kDoubleWord size
+    // with it then we could avoid this.
+    // TODO(vegorov) implement and use UBFM for zero extension.
+    __ Lsl(out, value, 32);
+    __ Lsr(out, out, 32);
+  } else if (from() == kUnboxedUint32 && to() == kUnboxedInt32) {
+    // Representations are bitwise equivalent.
+    // TODO(vegorov) if we ensure that we never use kDoubleWord size
+    // with it then we could avoid this.
+    // TODO(vegorov) implement and use SBFM for sign extension.
+    const Register value = locs()->in(0).reg();
+    const Register out = locs()->out(0).reg();
+    __ Lsl(out, value, 32);
+    __ Asr(out, out, 32);
+    if (CanDeoptimize()) {
+      Label* deopt =
+          compiler->AddDeoptStub(deopt_id(), ICData::kDeoptUnboxInteger);
+      __ cmp(out, Operand(value, UXTW, 0));
+      __ b(deopt, NE);
+    }
+  } else if (from() == kUnboxedMint) {
+    UNREACHABLE();
+  } else if (to() == kUnboxedMint) {
+    ASSERT((from() == kUnboxedUint32) || (from() == kUnboxedInt32));
+    UNREACHABLE();
+  } else {
+    UNREACHABLE();
+  }
+}
+
 
 LocationSummary* ThrowInstr::MakeLocationSummary(Isolate* isolate,
                                                  bool opt) const {
   return new(isolate) LocationSummary(isolate, 0, 0, LocationSummary::kCall);
 }
 
 
 void ThrowInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   compiler->GenerateRuntimeCall(token_pos(),
                                 deopt_id(),
@@ skipping 222 matching lines @@
   compiler->GenerateCall(token_pos(), &label, stub_kind_, locs());
 #if defined(DEBUG)
   __ LoadImmediate(R4, kInvalidObjectPointer, kNoPP);
   __ LoadImmediate(R5, kInvalidObjectPointer, kNoPP);
 #endif
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM64