MIPS: Optimize Smi keys for KeyedLoads

Port r12156 (e2874cdf)

Original commit message:
Allows KeyeLoad/KeyedStore operations where the key is a Smi to fold the untagging of the key into the element offset calculation.

BUG=
TEST=

Review URL: https://chromiumcodereview.appspot.com/10790143
Patch from Akos Palfi <palfia@homejinni.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12189 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/mips/lithium-codegen-mips.cc

@@ -2530,8 +2530,13 @@ void LCodeGen::DoLoadKeyedFastElement(LLoadKeyedFastElement* instr) {
   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));
@@ -2557,8 +2562,9 @@ void LCodeGen::DoLoadKeyedFastDoubleElement(
   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()));
@@ -2571,14 +2577,15 @@ void LCodeGen::DoLoadKeyedFastDoubleElement(
 
   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()) {
@@ -2590,6 +2597,50 @@ void LCodeGen::DoLoadKeyedFastDoubleElement(
 }
 
 
+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());
@@ -2605,14 +2656,16 @@ void LCodeGen::DoLoadKeyedSpecializedArrayElement(
   } 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);
@@ -2626,24 +2679,10 @@ void LCodeGen::DoLoadKeyedSpecializedArrayElement(
     }
   } 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);
@@ -3574,8 +3613,13 @@ void LCodeGen::DoStoreKeyedFastElement(LStoreKeyedFastElement* instr) {
         + 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,
@@ -3621,9 +3665,11 @@ void LCodeGen::DoStoreKeyedFastDoubleElement(
   } 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);
@@ -3644,7 +3690,8 @@ void LCodeGen::DoStoreKeyedFastDoubleElement(
   }
 
   __ bind(&not_nan);
-  __ sdc1(value, MemOperand(scratch, instr->additional_index() << shift_size));
+  __ sdc1(value, MemOperand(scratch, instr->additional_index() <<
+      element_size_shift));
 }
 
 
@@ -3664,14 +3711,17 @@ void LCodeGen::DoStoreKeyedSpecializedArrayElement(
   } 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);
@@ -3685,24 +3735,10 @@ void LCodeGen::DoStoreKeyedSpecializedArrayElement(
     }
   } 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:

src/mips/lithium-codegen-mips.h

@@ -128,6 +128,15 @@ class LCodeGen BASE_EMBEDDED {
   void DoParallelMove(LParallelMove* move);
   void DoGap(LGap* instr);
 
+  MemOperand PrepareKeyedOperand(Register key,
+                                 Register base,
+                                 bool key_is_constant,
+                                 int constant_key,
+                                 int element_size,
+                                 int shift_size,
+                                 int additional_index,
+                                 int additional_offset);
+
   // Emit frame translation commands for an environment.
   void WriteTranslation(LEnvironment* environment, Translation* translation);
 

src/mips/lithium-mips.cc

@@ -1773,7 +1773,8 @@ LInstruction* LChunkBuilder::DoLoadExternalArrayPointer(
 LInstruction* LChunkBuilder::DoLoadKeyedFastElement(
     HLoadKeyedFastElement* instr) {
   ASSERT(instr->representation().IsTagged());
-  ASSERT(instr->key()->representation().IsInteger32());
+  ASSERT(instr->key()->representation().IsInteger32() ||
+         instr->key()->representation().IsTagged());
   LOperand* obj = UseRegisterAtStart(instr->object());
   LOperand* key = UseRegisterAtStart(instr->key());
   LLoadKeyedFastElement* result = new(zone()) LLoadKeyedFastElement(obj, key);
@@ -1785,7 +1786,8 @@ LInstruction* LChunkBuilder::DoLoadKeyedFastElement(
 LInstruction* LChunkBuilder::DoLoadKeyedFastDoubleElement(
     HLoadKeyedFastDoubleElement* instr) {
   ASSERT(instr->representation().IsDouble());
-  ASSERT(instr->key()->representation().IsInteger32());
+  ASSERT(instr->key()->representation().IsInteger32() ||
+         instr->key()->representation().IsTagged());
   LOperand* elements = UseTempRegister(instr->elements());
   LOperand* key = UseRegisterOrConstantAtStart(instr->key());
   LLoadKeyedFastDoubleElement* result =
@@ -1805,7 +1807,8 @@ LInstruction* LChunkBuilder::DoLoadKeyedSpecializedArrayElement(
       (representation.IsDouble() &&
        ((elements_kind == EXTERNAL_FLOAT_ELEMENTS) ||
        (elements_kind == EXTERNAL_DOUBLE_ELEMENTS))));
-  ASSERT(instr->key()->representation().IsInteger32());
+  ASSERT(instr->key()->representation().IsInteger32() ||
+         instr->key()->representation().IsTagged());
   LOperand* external_pointer = UseRegister(instr->external_pointer());
   LOperand* key = UseRegisterOrConstant(instr->key());
   LLoadKeyedSpecializedArrayElement* result =
@@ -1833,7 +1836,8 @@ LInstruction* LChunkBuilder::DoStoreKeyedFastElement(
   bool needs_write_barrier = instr->NeedsWriteBarrier();
   ASSERT(instr->value()->representation().IsTagged());
   ASSERT(instr->object()->representation().IsTagged());
-  ASSERT(instr->key()->representation().IsInteger32());
+  ASSERT(instr->key()->representation().IsInteger32() ||
+         instr->key()->representation().IsTagged());
 
   LOperand* obj = UseTempRegister(instr->object());
   LOperand* val = needs_write_barrier
@@ -1850,7 +1854,8 @@ LInstruction* LChunkBuilder::DoStoreKeyedFastDoubleElement(
     HStoreKeyedFastDoubleElement* instr) {
   ASSERT(instr->value()->representation().IsDouble());
   ASSERT(instr->elements()->representation().IsTagged());
-  ASSERT(instr->key()->representation().IsInteger32());
+  ASSERT(instr->key()->representation().IsInteger32() ||
+         instr->key()->representation().IsTagged());
 
   LOperand* elements = UseRegisterAtStart(instr->elements());
   LOperand* val = UseTempRegister(instr->value());
@@ -1872,7 +1877,8 @@ LInstruction* LChunkBuilder::DoStoreKeyedSpecializedArrayElement(
        ((elements_kind == EXTERNAL_FLOAT_ELEMENTS) ||
        (elements_kind == EXTERNAL_DOUBLE_ELEMENTS))));
   ASSERT(instr->external_pointer()->representation().IsExternal());
-  ASSERT(instr->key()->representation().IsInteger32());
+  ASSERT(instr->key()->representation().IsInteger32() ||
+         instr->key()->representation().IsTagged());
 
   LOperand* external_pointer = UseRegister(instr->external_pointer());
   bool val_is_temp_register =

src/mips/lithium-mips.h

@@ -843,6 +843,7 @@ class LBoundsCheck: public LTemplateInstruction<0, 2, 0> {
   LOperand* length() { return inputs_[1]; }
 
   DECLARE_CONCRETE_INSTRUCTION(BoundsCheck, "bounds-check")
+  DECLARE_HYDROGEN_ACCESSOR(BoundsCheck)
 };