MIPS: Optimize Smi keys for KeyedLoads

src/mips/lithium-codegen-mips.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 2510 matching lines @@
 }
 
 
 void LCodeGen::DoLoadKeyedFastElement(LLoadKeyedFastElement* instr) {
   Register elements = ToRegister(instr->elements());
   Register key = EmitLoadRegister(instr->key(), scratch0());
   Register result = ToRegister(instr->result());
   Register scratch = scratch0();
 
   // Load the result.
-  __ sll(scratch, key, kPointerSizeLog2);  // Key indexes words.
-  __ addu(scratch, elements, scratch);
+  if (instr->hydrogen()->key()->representation().IsTagged()) {
+    __ sll(scratch, key, kPointerSizeLog2 - kSmiTagSize);
+    __ addu(scratch, elements, scratch);
+  } else {
+    __ sll(scratch, key, kPointerSizeLog2);
+    __ addu(scratch, elements, scratch);
+  }
   uint32_t offset = FixedArray::kHeaderSize +
                     (instr->additional_index() << kPointerSizeLog2);
   __ lw(result, FieldMemOperand(scratch, offset));
 
   // Check for the hole value.
   if (instr->hydrogen()->RequiresHoleCheck()) {
     if (IsFastSmiElementsKind(instr->hydrogen()->elements_kind())) {
       __ And(scratch, result, Operand(kSmiTagMask));
       DeoptimizeIf(ne, instr->environment(), scratch, Operand(zero_reg));
     } else {
       __ LoadRoot(scratch, Heap::kTheHoleValueRootIndex);
       DeoptimizeIf(eq, instr->environment(), result, Operand(scratch));
     }
   }
 }
 
 
 void LCodeGen::DoLoadKeyedFastDoubleElement(
     LLoadKeyedFastDoubleElement* instr) {
   Register elements = ToRegister(instr->elements());
   bool key_is_constant = instr->key()->IsConstantOperand();
   Register key = no_reg;
   DoubleRegister result = ToDoubleRegister(instr->result());
   Register scratch = scratch0();
 
-  int shift_size =
-      ElementsKindToShiftSize(FAST_DOUBLE_ELEMENTS);
+  int element_size_shift = ElementsKindToShiftSize(FAST_DOUBLE_ELEMENTS);
+  int shift_size = (instr->hydrogen()->key()->representation().IsTagged())
+      ? (element_size_shift - kSmiTagSize) : element_size_shift;
   int constant_key = 0;
   if (key_is_constant) {
     constant_key = ToInteger32(LConstantOperand::cast(instr->key()));
     if (constant_key & 0xF0000000) {
       Abort("array index constant value too big.");
     }
   } else {
     key = ToRegister(instr->key());
   }
 
   if (key_is_constant) {
     __ Addu(elements, elements,
-        Operand(((constant_key + instr->additional_index()) << shift_size) +
+        Operand(((constant_key + instr->additional_index()) <<
+                 element_size_shift) +
                 FixedDoubleArray::kHeaderSize - kHeapObjectTag));
   } else {
     __ sll(scratch, key, shift_size);
     __ Addu(elements, elements, Operand(scratch));
     __ Addu(elements, elements,
             Operand((FixedDoubleArray::kHeaderSize - kHeapObjectTag) +
-                    (instr->additional_index() << shift_size)));
+                    (instr->additional_index() << element_size_shift)));
   }
 
   if (instr->hydrogen()->RequiresHoleCheck()) {
     __ lw(scratch, MemOperand(elements, sizeof(kHoleNanLower32)));
     DeoptimizeIf(eq, instr->environment(), scratch, Operand(kHoleNanUpper32));
   }
 
   __ ldc1(result, MemOperand(elements));
 }
 
 
+MemOperand LCodeGen::PrepareKeyedOperand(Register key,
+                                         Register base,
+                                         bool key_is_constant,
+                                         int constant_key,
+                                         int element_size,
+                                         int shift_size,
+                                         int additional_index,
+                                         int additional_offset) {
+  if (additional_index != 0 && !key_is_constant) {
+    additional_index *= 1 << (element_size - shift_size);
+    __ Addu(scratch0(), key, Operand(additional_index));
+  }
+
+  if (key_is_constant) {
+    return MemOperand(base,
+                      (constant_key << element_size) + additional_offset);
+  }
+
+  if (additional_index == 0) {
+    if (shift_size >= 0) {
+      __ sll(scratch0(), key, shift_size);
+      __ Addu(scratch0(), base, scratch0());
+      return MemOperand(scratch0());
+    } else {
+      ASSERT_EQ(-1, shift_size);
+      __ srl(scratch0(), key, 1);
+      __ Addu(scratch0(), base, scratch0());
+      return MemOperand(scratch0());
+    }
+  }
+
+  if (shift_size >= 0) {
+    __ sll(scratch0(), scratch0(), shift_size);
+    __ Addu(scratch0(), base, scratch0());
+    return MemOperand(scratch0());
+  } else {
+    ASSERT_EQ(-1, shift_size);
+    __ srl(scratch0(), scratch0(), 1);
+    __ Addu(scratch0(), base, scratch0());
+    return MemOperand(scratch0());
+  }
+}
+
+
 void LCodeGen::DoLoadKeyedSpecializedArrayElement(
     LLoadKeyedSpecializedArrayElement* instr) {
   Register external_pointer = ToRegister(instr->external_pointer());
   Register key = no_reg;
   ElementsKind elements_kind = instr->elements_kind();
   bool key_is_constant = instr->key()->IsConstantOperand();
   int constant_key = 0;
   if (key_is_constant) {
     constant_key = ToInteger32(LConstantOperand::cast(instr->key()));
     if (constant_key & 0xF0000000) {
       Abort("array index constant value too big.");
     }
   } else {
     key = ToRegister(instr->key());
   }
-  int shift_size = ElementsKindToShiftSize(elements_kind);
-  int additional_offset = instr->additional_index() << shift_size;
+  int element_size_shift = ElementsKindToShiftSize(elements_kind);
+  int shift_size = (instr->hydrogen()->key()->representation().IsTagged())
+      ? (element_size_shift - kSmiTagSize) : element_size_shift;
+  int additional_offset = instr->additional_index() << element_size_shift;
 
   if (elements_kind == EXTERNAL_FLOAT_ELEMENTS ||
       elements_kind == EXTERNAL_DOUBLE_ELEMENTS) {
     FPURegister result = ToDoubleRegister(instr->result());
     if (key_is_constant) {
-      __ Addu(scratch0(), external_pointer, constant_key << shift_size);
+      __ Addu(scratch0(), external_pointer, constant_key << element_size_shift);
     } else {
       __ sll(scratch0(), key, shift_size);
       __ Addu(scratch0(), scratch0(), external_pointer);
     }
 
     if (elements_kind == EXTERNAL_FLOAT_ELEMENTS) {
       __ lwc1(result, MemOperand(scratch0(), additional_offset));
       __ cvt_d_s(result, result);
     } else  {  // i.e. elements_kind == EXTERNAL_DOUBLE_ELEMENTS
       __ ldc1(result, MemOperand(scratch0(), additional_offset));
     }
   } else {
     Register result = ToRegister(instr->result());
-    Register scratch = scratch0();
-    if (instr->additional_index() != 0 && !key_is_constant) {
-      __ Addu(scratch, key, instr->additional_index());
-    }
-    MemOperand mem_operand(zero_reg);
-    if (key_is_constant) {
-      mem_operand =
-          MemOperand(external_pointer,
-                     (constant_key << shift_size) + additional_offset);
-    } else {
-      if (instr->additional_index() == 0) {
-        __ sll(scratch, key, shift_size);
-      } else {
-        __ sll(scratch, scratch, shift_size);
-      }
-      __ Addu(scratch, scratch, external_pointer);
-      mem_operand = MemOperand(scratch);
-    }
+    MemOperand mem_operand = PrepareKeyedOperand(
+        key, external_pointer, key_is_constant, constant_key,
+        element_size_shift, shift_size,
+        instr->additional_index(), additional_offset);
     switch (elements_kind) {
       case EXTERNAL_BYTE_ELEMENTS:
         __ lb(result, mem_operand);
         break;
       case EXTERNAL_PIXEL_ELEMENTS:
       case EXTERNAL_UNSIGNED_BYTE_ELEMENTS:
         __ lbu(result, mem_operand);
         break;
       case EXTERNAL_SHORT_ELEMENTS:
         __ lh(result, mem_operand);
@@ skipping 910 matching lines @@
 
   // Do the store.
   if (instr->key()->IsConstantOperand()) {
     ASSERT(!instr->hydrogen()->NeedsWriteBarrier());
     LConstantOperand* const_operand = LConstantOperand::cast(instr->key());
     int offset =
         (ToInteger32(const_operand) + instr->additional_index()) * kPointerSize
         + FixedArray::kHeaderSize;
     __ sw(value, FieldMemOperand(elements, offset));
   } else {
-    __ sll(scratch, key, kPointerSizeLog2);
-    __ addu(scratch, elements, scratch);
+    if (instr->hydrogen()->key()->representation().IsTagged()) {
+      __ sll(scratch, key, kPointerSizeLog2 - kSmiTagSize);
+      __ addu(scratch, elements, scratch);
+    } else {
+      __ sll(scratch, key, kPointerSizeLog2);
+      __ addu(scratch, elements, scratch);
+    }
     if (instr->additional_index() != 0) {
       __ Addu(scratch,
               scratch,
               instr->additional_index() << kPointerSizeLog2);
     }
     __ sw(value, FieldMemOperand(scratch, FixedArray::kHeaderSize));
   }
 
   if (instr->hydrogen()->NeedsWriteBarrier()) {
     HType type = instr->hydrogen()->value()->type();
@@ skipping 25 matching lines @@
   // Calculate the effective address of the slot in the array to store the
   // double value.
   if (key_is_constant) {
     constant_key = ToInteger32(LConstantOperand::cast(instr->key()));
     if (constant_key & 0xF0000000) {
       Abort("array index constant value too big.");
     }
   } else {
     key = ToRegister(instr->key());
   }
-  int shift_size = ElementsKindToShiftSize(FAST_DOUBLE_ELEMENTS);
+  int element_size_shift = ElementsKindToShiftSize(FAST_DOUBLE_ELEMENTS);
+  int shift_size = (instr->hydrogen()->key()->representation().IsTagged())
+      ? (element_size_shift - kSmiTagSize) : element_size_shift;
   if (key_is_constant) {
-    __ Addu(scratch, elements, Operand((constant_key << shift_size) +
+    __ Addu(scratch, elements, Operand((constant_key << element_size_shift) +
             FixedDoubleArray::kHeaderSize - kHeapObjectTag));
   } else {
     __ sll(scratch, key, shift_size);
     __ Addu(scratch, elements, Operand(scratch));
     __ Addu(scratch, scratch,
             Operand(FixedDoubleArray::kHeaderSize - kHeapObjectTag));
   }
 
   if (instr->NeedsCanonicalization()) {
     Label is_nan;
     // Check for NaN. All NaNs must be canonicalized.
     __ BranchF(NULL, &is_nan, eq, value, value);
     __ Branch(&not_nan);
 
     // Only load canonical NaN if the comparison above set the overflow.
     __ bind(&is_nan);
     __ Move(value, FixedDoubleArray::canonical_not_the_hole_nan_as_double());
   }
 
   __ bind(&not_nan);
-  __ sdc1(value, MemOperand(scratch, instr->additional_index() << shift_size));
+  __ sdc1(value, MemOperand(scratch, instr->additional_index() <<
+      element_size_shift));
 }
 
 
 void LCodeGen::DoStoreKeyedSpecializedArrayElement(
     LStoreKeyedSpecializedArrayElement* instr) {
 
   Register external_pointer = ToRegister(instr->external_pointer());
   Register key = no_reg;
   ElementsKind elements_kind = instr->elements_kind();
   bool key_is_constant = instr->key()->IsConstantOperand();
   int constant_key = 0;
   if (key_is_constant) {
     constant_key = ToInteger32(LConstantOperand::cast(instr->key()));
     if (constant_key & 0xF0000000) {
       Abort("array index constant value too big.");
     }
   } else {
     key = ToRegister(instr->key());
   }
-  int shift_size = ElementsKindToShiftSize(elements_kind);
-  int additional_offset = instr->additional_index() << shift_size;
+  int element_size_shift = ElementsKindToShiftSize(elements_kind);
+  int shift_size = (instr->hydrogen()->key()->representation().IsTagged())
+      ? (element_size_shift - kSmiTagSize) : element_size_shift;
+  int additional_offset = instr->additional_index() << element_size_shift;
 
   if (elements_kind == EXTERNAL_FLOAT_ELEMENTS ||
       elements_kind == EXTERNAL_DOUBLE_ELEMENTS) {
     FPURegister value(ToDoubleRegister(instr->value()));
     if (key_is_constant) {
-      __ Addu(scratch0(), external_pointer, constant_key << shift_size);
+      __ Addu(scratch0(), external_pointer, constant_key <<
+          element_size_shift);
     } else {
       __ sll(scratch0(), key, shift_size);
       __ Addu(scratch0(), scratch0(), external_pointer);
     }
 
     if (elements_kind == EXTERNAL_FLOAT_ELEMENTS) {
       __ cvt_s_d(double_scratch0(), value);
       __ swc1(double_scratch0(), MemOperand(scratch0(), additional_offset));
     } else {  // i.e. elements_kind == EXTERNAL_DOUBLE_ELEMENTS
       __ sdc1(value, MemOperand(scratch0(), additional_offset));
     }
   } else {
     Register value(ToRegister(instr->value()));
-    Register scratch = scratch0();
-    if (instr->additional_index() != 0 && !key_is_constant) {
-      __ Addu(scratch, key, instr->additional_index());
-    }
-    MemOperand mem_operand(zero_reg);
-    if (key_is_constant) {
-      mem_operand = MemOperand(external_pointer,
-                               ((constant_key + instr->additional_index())
-                                   << shift_size));
-    } else {
-      if (instr->additional_index() == 0) {
-        __ sll(scratch, key, shift_size);
-      } else {
-        __ sll(scratch, scratch, shift_size);
-      }
-      __ Addu(scratch, scratch, external_pointer);
-      mem_operand = MemOperand(scratch);
-    }
+    MemOperand mem_operand = PrepareKeyedOperand(
+        key, external_pointer, key_is_constant, constant_key,
+        element_size_shift, shift_size,
+        instr->additional_index(), additional_offset);
     switch (elements_kind) {
       case EXTERNAL_PIXEL_ELEMENTS:
       case EXTERNAL_BYTE_ELEMENTS:
       case EXTERNAL_UNSIGNED_BYTE_ELEMENTS:
         __ sb(value, mem_operand);
         break;
       case EXTERNAL_SHORT_ELEMENTS:
       case EXTERNAL_UNSIGNED_SHORT_ELEMENTS:
         __ sh(value, mem_operand);
         break;
@@ skipping 1493 matching lines @@
   __ Subu(scratch, result, scratch);
   __ lw(result, FieldMemOperand(scratch,
                                 FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal