Some improvements in register usage in lithium compilation of LoadKeyed/StoreKeyed operations.

src/x64/lithium-codegen-x64.cc

 // Copyright 2012 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
@@ skipping 2594 matching lines @@
   // Subtracting from length accounts for one of them add one more.
   if (instr->index()->IsRegister()) {
     __ subl(length, ToRegister(instr->index()));
   } else {
     __ subl(length, ToOperand(instr->index()));
   }
   __ movq(result, Operand(arguments, length, times_pointer_size, kPointerSize));
 }
 
 
+template <class T>
+inline void LCodeGen::HandleKeyedAlterations(T* hydrogen_instr, LOperand* key) {

[danno, 2012/11/07 22:34:38]

How about "PrepareKeyForKeyedOp" or "PrepareKeyForKeyedOperation"?

[mvstanton, 2012/11/09 09:43:13]

Done.

+  if (ArrayOpClobbersKey<T>(hydrogen_instr)) {
+    // 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()) {
+      __ SmiToInteger64(key_reg, key_reg);
+    } else if (hydrogen_instr->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();
-  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.
-    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);
-    }
-  }
+  HandleKeyedAlterations(instr->hydrogen(), key);
   Operand operand(BuildFastArrayOperand(
       instr->elements(),
       key,
       elements_kind,
       0,
       instr->additional_index()));
 
   if (elements_kind == EXTERNAL_FLOAT_ELEMENTS) {
     XMMRegister result(ToDoubleRegister(instr->result()));
     __ movss(result, operand);
@@ skipping 39 matching lines @@
         UNREACHABLE();
         break;
     }
   }
 }
 
 
 void LCodeGen::DoLoadKeyedFixedDoubleArray(LLoadKeyed* instr) {
   XMMRegister result(ToDoubleRegister(instr->result()));
   LOperand* key = instr->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);
-    }
-  }
-
+  HandleKeyedAlterations<HLoadKeyed>(instr->hydrogen(), key);
   if (instr->hydrogen()->RequiresHoleCheck()) {
     int offset = FixedDoubleArray::kHeaderSize - kHeapObjectTag +
         sizeof(kHoleNanLower32);
     Operand hole_check_operand = BuildFastArrayOperand(
         instr->elements(),
         key,
         FAST_DOUBLE_ELEMENTS,
         offset,
         instr->additional_index());
     __ cmpl(hole_check_operand, Immediate(kHoleNanUpper32));
     DeoptimizeIf(equal, instr->environment());
   }
 
   Operand double_load_operand = BuildFastArrayOperand(
       instr->elements(),
       key,
       FAST_DOUBLE_ELEMENTS,
       FixedDoubleArray::kHeaderSize - kHeapObjectTag,
       instr->additional_index());
   __ movsd(result, double_load_operand);
 }
 
 
 void LCodeGen::DoLoadKeyedFixedArray(LLoadKeyed* instr) {
   Register result = ToRegister(instr->result());
   LOperand* key = instr->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);
-    }
-  }
+  HandleKeyedAlterations<HLoadKeyed>(instr->hydrogen(), key);
 
   // Load the result.
   __ movq(result,
           BuildFastArrayOperand(instr->elements(),
                                 key,
                                 FAST_ELEMENTS,
                                 FixedArray::kHeaderSize - kHeapObjectTag,
                                 instr->additional_index()));
 
   // Check for the hole value.
@@ skipping 974 matching lines @@
       __ cmpq(length, ToRegister(instr->index()));
     }
   }
   DeoptimizeIf(below_equal, instr->environment());
 }
 
 
 void LCodeGen::DoStoreKeyedExternalArray(LStoreKeyed* instr) {
   ElementsKind elements_kind = instr->elements_kind();
   LOperand* key = instr->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);
-    }
-  }
+  HandleKeyedAlterations<HStoreKeyed>(instr->hydrogen(), key);
   Operand operand(BuildFastArrayOperand(
       instr->elements(),
       key,
       elements_kind,
       0,
       instr->additional_index()));
 
   if (elements_kind == EXTERNAL_FLOAT_ELEMENTS) {
     XMMRegister value(ToDoubleRegister(instr->value()));
     __ cvtsd2ss(value, value);
@@ skipping 29 matching lines @@
         UNREACHABLE();
         break;
     }
   }
 }
 
 
 void LCodeGen::DoStoreKeyedFixedDoubleArray(LStoreKeyed* instr) {
   XMMRegister value = ToDoubleRegister(instr->value());
   LOperand* key = instr->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);
-    }
-  }
-
+  HandleKeyedAlterations<HStoreKeyed>(instr->hydrogen(), key);
   if (instr->NeedsCanonicalization()) {
     Label have_value;
 
     __ ucomisd(value, value);
     __ j(parity_odd, &have_value);  // NaN.
 
     __ Set(kScratchRegister, BitCast<uint64_t>(
         FixedDoubleArray::canonical_not_the_hole_nan_as_double()));
     __ movq(value, kScratchRegister);
 
     __ bind(&have_value);
   }
 
   Operand double_store_operand = BuildFastArrayOperand(
       instr->elements(),
       key,
       FAST_DOUBLE_ELEMENTS,
       FixedDoubleArray::kHeaderSize - kHeapObjectTag,
       instr->additional_index());
 
   __ movsd(double_store_operand, value);
 }
 
 
 void LCodeGen::DoStoreKeyedFixedArray(LStoreKeyed* instr) {
   Register value = ToRegister(instr->value());
   Register elements = ToRegister(instr->elements());
   LOperand* key = instr->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);
-    }
-  }
+  HandleKeyedAlterations<HStoreKeyed>(instr->hydrogen(), key);
 
   Operand operand =
       BuildFastArrayOperand(instr->elements(),
                             key,
                             FAST_ELEMENTS,
                             FixedArray::kHeaderSize - kHeapObjectTag,
                             instr->additional_index());
 
   if (instr->hydrogen()->NeedsWriteBarrier()) {
     ASSERT(!instr->key()->IsConstantOperand());
@@ skipping 1460 matching lines @@
                                FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64