Add Smi support to Shl

R=mvstanton@chromium.org

Review URL: https://chromiumcodereview.appspot.com/20323002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15910 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

diff --git a/src/arm/lithium-arm.cc b/src/arm/lithium-arm.cc
index 0000146..53b777d 100644 (file)
--- a/src/arm/lithium-arm.cc
+++ b/src/arm/lithium-arm.cc
@@ -708,9 +708,9 @@ LInstruction* LChunkBuilder::DoDeoptimize(HDeoptimize* instr) {
 
 LInstruction* LChunkBuilder::DoShift(Token::Value op,
                                      HBitwiseBinaryOperation* instr) {
-  if (instr->representation().IsSmiOrTagged()) {
-    ASSERT(instr->left()->representation().IsSmiOrTagged());
-    ASSERT(instr->right()->representation().IsSmiOrTagged());
+  if (instr->representation().IsTagged()) {
+    ASSERT(instr->left()->representation().IsTagged());
+    ASSERT(instr->right()->representation().IsTagged());
 
     LOperand* left = UseFixed(instr->left(), r1);
     LOperand* right = UseFixed(instr->right(), r0);
@@ -718,25 +718,35 @@ LInstruction* LChunkBuilder::DoShift(Token::Value op,
     return MarkAsCall(DefineFixed(result, r0), instr);
   }
 
-  ASSERT(instr->representation().IsInteger32());
-  ASSERT(instr->left()->representation().IsInteger32());
-  ASSERT(instr->right()->representation().IsInteger32());
+  ASSERT(instr->representation().IsSmiOrInteger32());
+  ASSERT(instr->left()->representation().Equals(instr->representation()));
+  ASSERT(instr->right()->representation().Equals(instr->representation()));
   LOperand* left = UseRegisterAtStart(instr->left());
 
   HValue* right_value = instr->right();
   LOperand* right = NULL;
   int constant_value = 0;
+  bool does_deopt = false;
   if (right_value->IsConstant()) {
     HConstant* constant = HConstant::cast(right_value);
     right = chunk_->DefineConstantOperand(constant);
     constant_value = constant->Integer32Value() & 0x1f;
+    // Left shifts can deoptimize if we shift by > 0 and the result cannot be
+    // truncated to smi.
+    if (instr->representation().IsSmi() && constant_value > 0) {
+      for (HUseIterator it(instr->uses()); !it.Done(); it.Advance()) {
+        if (!it.value()->CheckFlag(HValue::kTruncatingToSmi)) {
+          does_deopt = true;
+          break;
+        }
+      }
+    }
   } else {
     right = UseRegisterAtStart(right_value);
   }
 
   // Shift operations can only deoptimize if we do a logical shift
   // by 0 and the result cannot be truncated to int32.
-  bool does_deopt = false;
   if (op == Token::SHR && constant_value == 0) {
     if (FLAG_opt_safe_uint32_operations) {
       does_deopt = !instr->CheckFlag(HInstruction::kUint32);

diff --git a/src/arm/lithium-codegen-arm.cc b/src/arm/lithium-codegen-arm.cc
index 41636a8..ff1c33b 100644 (file)
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -1742,7 +1742,14 @@ void LCodeGen::DoShiftI(LShiftI* instr) {
         break;
       case Token::SHL:
         if (shift_count != 0) {
-          __ mov(result, Operand(left, LSL, shift_count));
+          if (instr->hydrogen_value()->representation().IsSmi() &&
+              instr->can_deopt()) {
+            __ mov(result, Operand(left, LSL, shift_count - 1));
+            __ SmiTag(result, result, SetCC);
+            DeoptimizeIf(vs, instr->environment());
+          } else {
+            __ mov(result, Operand(left, LSL, shift_count));
+          }
         } else {
           __ Move(result, left);
         }

diff --git a/src/hydrogen-instructions.h b/src/hydrogen-instructions.h
index bf59159..c36388e 100644 (file)
--- a/src/hydrogen-instructions.h
+++ b/src/hydrogen-instructions.h
@@ -4890,7 +4890,11 @@ class HShl: public HBitwiseBinaryOperation {
   virtual void UpdateRepresentation(Representation new_rep,
                                     HInferRepresentationPhase* h_infer,
                                     const char* reason) {
-    if (new_rep.IsSmi()) new_rep = Representation::Integer32();
+    if (new_rep.IsSmi() &&
+        !(right()->IsInteger32Constant() &&
+          right()->GetInteger32Constant() >= 0)) {
+      new_rep = Representation::Integer32();
+    }
     HBitwiseBinaryOperation::UpdateRepresentation(new_rep, h_infer, reason);
   }
 

diff --git a/src/ia32/lithium-codegen-ia32.cc b/src/ia32/lithium-codegen-ia32.cc
index d022a82..de936b4 100644 (file)
--- a/src/ia32/lithium-codegen-ia32.cc
+++ b/src/ia32/lithium-codegen-ia32.cc
@@ -1762,7 +1762,14 @@ void LCodeGen::DoShiftI(LShiftI* instr) {
         break;
       case Token::SHL:
         if (shift_count != 0) {
-          __ shl(ToRegister(left), shift_count);
+          if (instr->hydrogen_value()->representation().IsSmi() &&
+              instr->can_deopt()) {
+            __ shl(ToRegister(left), shift_count - 1);
+            __ SmiTag(ToRegister(left));
+            DeoptimizeIf(overflow, instr->environment());
+          } else {
+            __ shl(ToRegister(left), shift_count);
+          }
         }
         break;
       default:

diff --git a/src/ia32/lithium-ia32.cc b/src/ia32/lithium-ia32.cc
index f03cd72..2806b66 100644 (file)
--- a/src/ia32/lithium-ia32.cc
+++ b/src/ia32/lithium-ia32.cc
@@ -761,7 +761,7 @@ LInstruction* LChunkBuilder::DoDeoptimize(HDeoptimize* instr) {
 
 LInstruction* LChunkBuilder::DoShift(Token::Value op,
                                      HBitwiseBinaryOperation* instr) {
-  if (instr->representation().IsSmiOrTagged()) {
+  if (instr->representation().IsTagged()) {
     ASSERT(instr->left()->representation().IsSmiOrTagged());
     ASSERT(instr->right()->representation().IsSmiOrTagged());
 
@@ -772,25 +772,35 @@ LInstruction* LChunkBuilder::DoShift(Token::Value op,
     return MarkAsCall(DefineFixed(result, eax), instr);
   }
 
-  ASSERT(instr->representation().IsInteger32());
-  ASSERT(instr->left()->representation().IsInteger32());
-  ASSERT(instr->right()->representation().IsInteger32());
+  ASSERT(instr->representation().IsSmiOrInteger32());
+  ASSERT(instr->left()->representation().Equals(instr->representation()));
+  ASSERT(instr->right()->representation().Equals(instr->representation()));
   LOperand* left = UseRegisterAtStart(instr->left());
 
   HValue* right_value = instr->right();
   LOperand* right = NULL;
   int constant_value = 0;
+  bool does_deopt = false;
   if (right_value->IsConstant()) {
     HConstant* constant = HConstant::cast(right_value);
     right = chunk_->DefineConstantOperand(constant);
     constant_value = constant->Integer32Value() & 0x1f;
+    // Left shifts can deoptimize if we shift by > 0 and the result cannot be
+    // truncated to smi.
+    if (instr->representation().IsSmi() && constant_value > 0) {
+      for (HUseIterator it(instr->uses()); !it.Done(); it.Advance()) {
+        if (!it.value()->CheckFlag(HValue::kTruncatingToSmi)) {
+          does_deopt = true;
+          break;
+        }
+      }
+    }
   } else {
     right = UseFixed(right_value, ecx);
   }
 
   // Shift operations can only deoptimize if we do a logical shift by 0 and
   // the result cannot be truncated to int32.
-  bool does_deopt = false;
   if (op == Token::SHR && constant_value == 0) {
     if (FLAG_opt_safe_uint32_operations) {
       does_deopt = !instr->CheckFlag(HInstruction::kUint32);

diff --git a/src/x64/lithium-codegen-x64.cc b/src/x64/lithium-codegen-x64.cc
index d45076a..6f45b81 100644 (file)
--- a/src/x64/lithium-codegen-x64.cc
+++ b/src/x64/lithium-codegen-x64.cc
@@ -1453,7 +1453,11 @@ void LCodeGen::DoShiftI(LShiftI* instr) {
         break;
       case Token::SHL:
         if (shift_count != 0) {
-          __ shll(ToRegister(left), Immediate(shift_count));
+          if (instr->hydrogen_value()->representation().IsSmi()) {
+            __ shl(ToRegister(left), Immediate(shift_count));
+          } else {
+            __ shll(ToRegister(left), Immediate(shift_count));
+          }
         }
         break;
       default:

diff --git a/src/x64/lithium-x64.cc b/src/x64/lithium-x64.cc
index a6f9801..642cb27 100644 (file)
--- a/src/x64/lithium-x64.cc
+++ b/src/x64/lithium-x64.cc
@@ -717,9 +717,9 @@ LInstruction* LChunkBuilder::DoDeoptimize(HDeoptimize* instr) {
 
 LInstruction* LChunkBuilder::DoShift(Token::Value op,
                                      HBitwiseBinaryOperation* instr) {
-  if (instr->representation().IsSmiOrTagged()) {
-    ASSERT(instr->left()->representation().IsSmiOrTagged());
-    ASSERT(instr->right()->representation().IsSmiOrTagged());
+  if (instr->representation().IsTagged()) {
+    ASSERT(instr->left()->representation().IsTagged());
+    ASSERT(instr->right()->representation().IsTagged());
 
     LOperand* left = UseFixed(instr->left(), rdx);
     LOperand* right = UseFixed(instr->right(), rax);
@@ -727,9 +727,9 @@ LInstruction* LChunkBuilder::DoShift(Token::Value op,
     return MarkAsCall(DefineFixed(result, rax), instr);
   }
 
-  ASSERT(instr->representation().IsInteger32());
-  ASSERT(instr->left()->representation().IsInteger32());
-  ASSERT(instr->right()->representation().IsInteger32());
+  ASSERT(instr->representation().IsSmiOrInteger32());
+  ASSERT(instr->left()->representation().Equals(instr->representation()));
+  ASSERT(instr->right()->representation().Equals(instr->representation()));
   LOperand* left = UseRegisterAtStart(instr->left());
 
   HValue* right_value = instr->right();