Revert change r12912 due to x64 perf issue

src/x64/lithium-codegen-x64.cc

Index: src/x64/lithium-codegen-x64.cc
diff --git a/src/x64/lithium-codegen-x64.cc b/src/x64/lithium-codegen-x64.cc
index 4596aca2f7628e78bdd4bcc0d84bd5129abd348a..2bcf943ab6cb3963fe9c8b53f0a3679355c9048e 100644
--- a/src/x64/lithium-codegen-x64.cc
+++ b/src/x64/lithium-codegen-x64.cc
@@ -2624,30 +2624,24 @@ void LCodeGen::DoAccessArgumentsAt(LAccessArgumentsAt* instr) {
 }
 
 
-template <class T>
-inline void LCodeGen::PrepareKeyForKeyedOp(T* hydrogen_instr, LOperand* key) {
-  if (ArrayOpClobbersKey<T>(hydrogen_instr)) {
+void LCodeGen::DoLoadKeyedExternalArray(LLoadKeyed* instr) {
+  ElementsKind elements_kind = instr->elements_kind();
+  LOperand* key = instr->key();
+  if (!key->IsConstantOperand()) {
+    Register key_reg = ToRegister(key);
     // Even though the HLoad/StoreKeyed (in this case) instructions force
     // the input representation for the key to be an integer, the input
     // gets replaced during bound check elimination with the index argument
     // to the bounds check, which can be tagged, so that case must be
     // handled here, too.
-    Register key_reg = ToRegister(key);
-    if (hydrogen_instr->key()->representation().IsTagged()) {
+    if (instr->hydrogen()->key()->representation().IsTagged()) {
       __ SmiToInteger64(key_reg, key_reg);
-    } else if (hydrogen_instr->IsDehoisted()) {
+    } else if (instr->hydrogen()->IsDehoisted()) {
       // Sign extend key because it could be a 32 bit negative value
       // and the dehoisted address computation happens in 64 bits
       __ movsxlq(key_reg, key_reg);
     }
   }
-}
-
-
-void LCodeGen::DoLoadKeyedExternalArray(LLoadKeyed* instr) {
-  ElementsKind elements_kind = instr->elements_kind();
-  LOperand* key = instr->key();
-  PrepareKeyForKeyedOp(instr->hydrogen(), key);
   Operand operand(BuildFastArrayOperand(
       instr->elements(),
       key,
@@ -2707,7 +2701,21 @@ void LCodeGen::DoLoadKeyedExternalArray(LLoadKeyed* instr) {
 void LCodeGen::DoLoadKeyedFixedDoubleArray(LLoadKeyed* instr) {
   XMMRegister result(ToDoubleRegister(instr->result()));
   LOperand* key = instr->key();
-  PrepareKeyForKeyedOp<HLoadKeyed>(instr->hydrogen(), key);
+  if (!key->IsConstantOperand()) {
+    Register key_reg = ToRegister(key);
+    // Even though the HLoad/StoreKeyed instructions force the input
+    // representation for the key to be an integer, the input gets replaced
+    // during bound check elimination with the index argument to the bounds
+    // check, which can be tagged, so that case must be handled here, too.
+    if (instr->hydrogen()->key()->representation().IsTagged()) {
+      __ SmiToInteger64(key_reg, key_reg);
+    } else if (instr->hydrogen()->IsDehoisted()) {
+      // Sign extend key because it could be a 32 bit negative value
+      // and the dehoisted address computation happens in 64 bits
+      __ movsxlq(key_reg, key_reg);
+    }
+  }
+
   if (instr->hydrogen()->RequiresHoleCheck()) {
     int offset = FixedDoubleArray::kHeaderSize - kHeapObjectTag +
         sizeof(kHoleNanLower32);
@@ -2734,7 +2742,21 @@ void LCodeGen::DoLoadKeyedFixedDoubleArray(LLoadKeyed* instr) {
 void LCodeGen::DoLoadKeyedFixedArray(LLoadKeyed* instr) {
   Register result = ToRegister(instr->result());
   LOperand* key = instr->key();
-  PrepareKeyForKeyedOp<HLoadKeyed>(instr->hydrogen(), key);
+  if (!key->IsConstantOperand()) {
+    Register key_reg = ToRegister(key);
+    // Even though the HLoad/StoreKeyedFastElement instructions force
+    // the input representation for the key to be an integer, the input
+    // gets replaced during bound check elimination with the index
+    // argument to the bounds check, which can be tagged, so that
+    // case must be handled here, too.
+    if (instr->hydrogen()->key()->representation().IsTagged()) {
+      __ SmiToInteger64(key_reg, key_reg);
+    } else if (instr->hydrogen()->IsDehoisted()) {
+      // Sign extend key because it could be a 32 bit negative value
+      // and the dehoisted address computation happens in 64 bits
+      __ movsxlq(key_reg, key_reg);
+    }
+  }
 
   // Load the result.
   __ movq(result,
@@ -3729,7 +3751,21 @@ void LCodeGen::DoBoundsCheck(LBoundsCheck* instr) {
 void LCodeGen::DoStoreKeyedExternalArray(LStoreKeyed* instr) {
   ElementsKind elements_kind = instr->elements_kind();
   LOperand* key = instr->key();
-  PrepareKeyForKeyedOp<HStoreKeyed>(instr->hydrogen(), key);
+  if (!key->IsConstantOperand()) {
+    Register key_reg = ToRegister(key);
+    // Even though the HLoad/StoreKeyedFastElement instructions force
+    // the input representation for the key to be an integer, the input
+    // gets replaced during bound check elimination with the index
+    // argument to the bounds check, which can be tagged, so that case
+    // must be handled here, too.
+    if (instr->hydrogen()->key()->representation().IsTagged()) {
+      __ SmiToInteger64(key_reg, key_reg);
+    } else if (instr->hydrogen()->IsDehoisted()) {
+      // Sign extend key because it could be a 32 bit negative value
+      // and the dehoisted address computation happens in 64 bits
+      __ movsxlq(key_reg, key_reg);
+    }
+  }
   Operand operand(BuildFastArrayOperand(
       instr->elements(),
       key,
@@ -3779,7 +3815,22 @@ void LCodeGen::DoStoreKeyedExternalArray(LStoreKeyed* instr) {
 void LCodeGen::DoStoreKeyedFixedDoubleArray(LStoreKeyed* instr) {
   XMMRegister value = ToDoubleRegister(instr->value());
   LOperand* key = instr->key();
-  PrepareKeyForKeyedOp<HStoreKeyed>(instr->hydrogen(), key);
+  if (!key->IsConstantOperand()) {
+    Register key_reg = ToRegister(key);
+    // Even though the HLoad/StoreKeyedFastElement instructions force
+    // the input representation for the key to be an integer, the
+    // input gets replaced during bound check elimination with the index
+    // argument to the bounds check, which can be tagged, so that case
+    // must be handled here, too.
+    if (instr->hydrogen()->key()->representation().IsTagged()) {
+      __ SmiToInteger64(key_reg, key_reg);
+    } else if (instr->hydrogen()->IsDehoisted()) {
+      // Sign extend key because it could be a 32 bit negative value
+      // and the dehoisted address computation happens in 64 bits
+      __ movsxlq(key_reg, key_reg);
+    }
+  }
+
   if (instr->NeedsCanonicalization()) {
     Label have_value;
 
@@ -3808,7 +3859,21 @@ void LCodeGen::DoStoreKeyedFixedArray(LStoreKeyed* instr) {
   Register value = ToRegister(instr->value());
   Register elements = ToRegister(instr->elements());
   LOperand* key = instr->key();
-  PrepareKeyForKeyedOp<HStoreKeyed>(instr->hydrogen(), key);
+  if (!key->IsConstantOperand()) {
+    Register key_reg = ToRegister(key);
+    // Even though the HLoad/StoreKeyedFastElement instructions force
+    // the input representation for the key to be an integer, the
+    // input gets replaced during bound check elimination with the index
+    // argument to the bounds check, which can be tagged, so that case
+    // must be handled here, too.
+    if (instr->hydrogen()->key()->representation().IsTagged()) {
+      __ SmiToInteger64(key_reg, key_reg);
+    } else if (instr->hydrogen()->IsDehoisted()) {
+      // Sign extend key because it could be a 32 bit negative value
+      // and the dehoisted address computation happens in 64 bits
+      __ movsxlq(key_reg, key_reg);
+    }
+  }
 
   Operand operand =
       BuildFastArrayOperand(instr->elements(),