Fix uint32-to-smi conversion in Lithium

BUG=chromium:309623
R=vegorov@google.com, yangguo@chromium.org

Review URL: https://codereview.chromium.org/54393002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17441 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/lithium-arm.cc

@@ -2014,8 +2014,9 @@ LInstruction* LChunkBuilder::DoChange(HChange* instr) {
     } else if (to.IsSmi()) {
       HValue* val = instr->value();
       LOperand* value = UseRegister(val);
-      LInstruction* result =
-          DefineSameAsFirst(new(zone()) LInteger32ToSmi(value));
+      LInstruction* result = val->CheckFlag(HInstruction::kUint32)
+          ? DefineSameAsFirst(new(zone()) LUint32ToSmi(value))
+          : DefineSameAsFirst(new(zone()) LInteger32ToSmi(value));
       if (val->HasRange() && val->range()->IsInSmiRange()) {
         return result;
       }

src/arm/lithium-arm.h

@@ -184,6 +184,7 @@ class LCodeGen;
   V(Typeof)                                     \
   V(TypeofIsAndBranch)                          \
   V(Uint32ToDouble)                             \
+  V(Uint32ToSmi)                                \
   V(UnknownOSRValue)                            \
   V(ValueOf)                                    \
   V(WrapReceiver)
@@ -2074,6 +2075,19 @@ class LUint32ToDouble V8_FINAL : public LTemplateInstruction<1, 1, 0> {
 };
 
 
+class LUint32ToSmi V8_FINAL : public LTemplateInstruction<1, 1, 0> {
+ public:
+  explicit LUint32ToSmi(LOperand* value) {
+    inputs_[0] = value;
+  }
+
+  LOperand* value() { return inputs_[0]; }
+
+  DECLARE_CONCRETE_INSTRUCTION(Uint32ToSmi, "uint32-to-smi")
+  DECLARE_HYDROGEN_ACCESSOR(Change)
+};
+
+
 class LNumberTagI V8_FINAL : public LTemplateInstruction<1, 1, 0> {
  public:
   explicit LNumberTagI(LOperand* value) {

src/arm/lithium-codegen-arm.cc

@@ -4650,9 +4650,7 @@ void LCodeGen::DoInteger32ToDouble(LInteger32ToDouble* instr) {
 
 void LCodeGen::DoInteger32ToSmi(LInteger32ToSmi* instr) {
   LOperand* input = instr->value();
-  ASSERT(input->IsRegister());
   LOperand* output = instr->result();
-  ASSERT(output->IsRegister());
   __ SmiTag(ToRegister(output), ToRegister(input), SetCC);
   if (!instr->hydrogen()->value()->HasRange() ||
       !instr->hydrogen()->value()->range()->IsInSmiRange()) {
@@ -4671,6 +4669,18 @@ void LCodeGen::DoUint32ToDouble(LUint32ToDouble* instr) {
 }
 
 
+void LCodeGen::DoUint32ToSmi(LUint32ToSmi* instr) {
+  LOperand* input = instr->value();
+  LOperand* output = instr->result();
+  if (!instr->hydrogen()->value()->HasRange() ||
+      !instr->hydrogen()->value()->range()->IsInSmiRange()) {
+    __ tst(ToRegister(input), Operand(0xc0000000));
+    DeoptimizeIf(ne, instr->environment());
+  }
+  __ SmiTag(ToRegister(output), ToRegister(input));
+}
+
+
 void LCodeGen::DoNumberTagI(LNumberTagI* instr) {
   class DeferredNumberTagI V8_FINAL : public LDeferredCode {
    public:

src/hydrogen-uint32-analysis.cc

@@ -35,8 +35,17 @@ bool HUint32AnalysisPhase::IsSafeUint32Use(HValue* val, HValue* use) {
   // Operations that operate on bits are safe.
   if (use->IsBitwise() || use->IsShl() || use->IsSar() || use->IsShr()) {
     return true;
-  } else if (use->IsChange() || use->IsSimulate()) {
-    // Conversions and deoptimization have special support for unt32.
+  } else if (use->IsSimulate()) {
+    // Deoptimization has special support for uint32.
+    return true;
+  } else if (use->IsChange()) {
+    // Conversions have special support for uint32.
+    // This ASSERT guards that the conversion in question is actually
+    // implemented. Do not extend the whitelist without adding
+    // support to LChunkBuilder::DoChange().
+    ASSERT(HChange::cast(use)->to().IsDouble() ||
+           HChange::cast(use)->to().IsSmi() ||
+           HChange::cast(use)->to().IsTagged());
     return true;
   } else if (use->IsStoreKeyed()) {
     HStoreKeyed* store = HStoreKeyed::cast(use);

src/ia32/lithium-codegen-ia32.cc

@@ -5012,6 +5012,17 @@ void LCodeGen::DoUint32ToDouble(LUint32ToDouble* instr) {
 }
 
 
+void LCodeGen::DoUint32ToSmi(LUint32ToSmi* instr) {
+  Register input = ToRegister(instr->value());
+  if (!instr->hydrogen()->value()->HasRange() ||
+      !instr->hydrogen()->value()->range()->IsInSmiRange()) {
+    __ test(input, Immediate(0xc0000000));
+    DeoptimizeIf(not_zero, instr->environment());
+  }
+  __ SmiTag(input);
+}
+
+
 void LCodeGen::DoNumberTagI(LNumberTagI* instr) {
   class DeferredNumberTagI V8_FINAL : public LDeferredCode {
    public:

src/ia32/lithium-ia32.cc

@@ -2002,8 +2002,9 @@ LInstruction* LChunkBuilder::DoChange(HChange* instr) {
     } else if (to.IsSmi()) {
       HValue* val = instr->value();
       LOperand* value = UseRegister(val);
-      LInstruction* result =
-          DefineSameAsFirst(new(zone()) LInteger32ToSmi(value));
+      LInstruction* result = val->CheckFlag(HInstruction::kUint32)
+           ? DefineSameAsFirst(new(zone()) LUint32ToSmi(value))
+           : DefineSameAsFirst(new(zone()) LInteger32ToSmi(value));
       if (val->HasRange() && val->range()->IsInSmiRange()) {
         return result;
       }

src/ia32/lithium-ia32.h

@@ -183,6 +183,7 @@ class LCodeGen;
   V(Typeof)                                     \
   V(TypeofIsAndBranch)                          \
   V(Uint32ToDouble)                             \
+  V(Uint32ToSmi)                                \
   V(UnknownOSRValue)                            \
   V(ValueOf)                                    \
   V(WrapReceiver)
@@ -2076,6 +2077,19 @@ class LUint32ToDouble V8_FINAL : public LTemplateInstruction<1, 1, 1> {
 };
 
 
+class LUint32ToSmi V8_FINAL : public LTemplateInstruction<1, 1, 0> {
+ public:
+  explicit LUint32ToSmi(LOperand* value) {
+    inputs_[0] = value;
+  }
+
+  LOperand* value() { return inputs_[0]; }
+
+  DECLARE_CONCRETE_INSTRUCTION(Uint32ToSmi, "uint32-to-smi")
+  DECLARE_HYDROGEN_ACCESSOR(Change)
+};
+
+
 class LNumberTagI V8_FINAL : public LTemplateInstruction<1, 1, 0> {
  public:
   explicit LNumberTagI(LOperand* value) {

src/x64/lithium-codegen-x64.cc

@@ -4421,6 +4421,22 @@ void LCodeGen::DoUint32ToDouble(LUint32ToDouble* instr) {
 }
 
 
+void LCodeGen::DoUint32ToSmi(LUint32ToSmi* instr) {
+  LOperand* input = instr->value();
+  ASSERT(input->IsRegister());
+  LOperand* output = instr->result();
+  if (!instr->hydrogen()->value()->HasRange() ||
+      !instr->hydrogen()->value()->range()->IsInSmiRange() ||
+      instr->hydrogen()->value()->range()->upper() == kMaxInt) {
+    // The Range class can't express upper bounds in the (kMaxInt, kMaxUint32]
+    // interval, so we treat kMaxInt as a sentinel for this entire interval.
+    __ testl(ToRegister(input), Immediate(0x80000000));
+    DeoptimizeIf(not_zero, instr->environment());
+  }
+  __ Integer32ToSmi(ToRegister(output), ToRegister(input));
+}
+
+
 void LCodeGen::DoNumberTagI(LNumberTagI* instr) {
   LOperand* input = instr->value();
   ASSERT(input->IsRegister() && input->Equals(instr->result()));

src/x64/lithium-x64.cc

@@ -1883,10 +1883,18 @@ LInstruction* LChunkBuilder::DoChange(HChange* instr) {
     } else if (to.IsSmi()) {
       HValue* val = instr->value();
       LOperand* value = UseRegister(val);
-      LInstruction* result =
-          DefineAsRegister(new(zone()) LInteger32ToSmi(value));
-      if (val->HasRange() && val->range()->IsInSmiRange()) {
-        return result;
+      LInstruction* result = NULL;
+      if (val->CheckFlag(HInstruction::kUint32)) {
+        result = DefineAsRegister(new(zone()) LUint32ToSmi(value));
+        if (val->HasRange() && val->range()->IsInSmiRange() &&
+            val->range()->upper() != kMaxInt) {
+          return result;
+        }
+      } else {
+        result = DefineAsRegister(new(zone()) LInteger32ToSmi(value));
+        if (val->HasRange() && val->range()->IsInSmiRange()) {
+          return result;
+        }
       }
       return AssignEnvironment(result);
     } else {

src/x64/lithium-x64.h

@@ -181,6 +181,7 @@ class LCodeGen;
   V(Typeof)                                     \
   V(TypeofIsAndBranch)                          \
   V(Uint32ToDouble)                             \
+  V(Uint32ToSmi)                                \
   V(UnknownOSRValue)                            \
   V(ValueOf)                                    \
   V(WrapReceiver)
@@ -1943,6 +1944,19 @@ class LUint32ToDouble V8_FINAL : public LTemplateInstruction<1, 1, 1> {
 };
 
 
+class LUint32ToSmi V8_FINAL : public LTemplateInstruction<1, 1, 0> {
+ public:
+  explicit LUint32ToSmi(LOperand* value) {
+    inputs_[0] = value;
+  }
+
+  LOperand* value() { return inputs_[0]; }
+
+  DECLARE_CONCRETE_INSTRUCTION(Uint32ToSmi, "uint32-to-smi")
+  DECLARE_HYDROGEN_ACCESSOR(Change)
+};
+
+
 class LNumberTagI V8_FINAL : public LTemplateInstruction<1, 1, 0> {
  public:
   explicit LNumberTagI(LOperand* value) {

test/mjsunit/regress/regress-crbug-309623.js

+// Copyright 2013 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Flags: --allow-natives-syntax
+
+var u = new Uint32Array(2);
+u[0] = 1;
+u[1] = 0xEE6B2800;
+
+var a = [0, 1, 2];
+a[0] = 0;  // Kill the COW.
+assertTrue(%HasFastSmiElements(a));
+
+function foo(i) {
+  a[0] = u[i];
+  return a[0];
+}
+
+assertEquals(u[0], foo(0));
+assertEquals(u[0], foo(0));
+%OptimizeFunctionOnNextCall(foo);
+assertEquals(u[1], foo(1));