Port of string plus smi optimization from ia32 to x64 and ARM.

Review URL: http://codereview.chromium.org/668254

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4138 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/codegen-arm.cc

@@ -3681,7 +3681,8 @@ void CodeGenerator::GenerateNumberToString(ZoneList<Expression*>* args) {
   // Load the argument on the stack and jump to the runtime.
   Load(args->at(0));
 
-  frame_->CallRuntime(Runtime::kNumberToString, 1);
+  NumberToStringStub stub;
+  frame_->CallStub(&stub, 1);
   frame_->EmitPush(r0);
 }
 
@@ -5280,6 +5281,79 @@ static void EmitCheckForSymbols(MacroAssembler* masm, Label* slow) {
 }
 
 
+void NumberToStringStub::GenerateLookupNumberStringCache(MacroAssembler* masm,
+                                                         Register object,
+                                                         Register result,
+                                                         Register scratch1,
+                                                         Register scratch2,
+                                                         bool object_is_smi,
+                                                         Label* not_found) {
+  // Currently only lookup for smis. Check for smi if object is not known to be
+  // a smi.
+  if (!object_is_smi) {
+    ASSERT(kSmiTag == 0);
+    __ tst(object, Operand(kSmiTagMask));
+    __ b(ne, not_found);
+  }
+
+  // Use of registers. Register result is used as a temporary.
+  Register number_string_cache = result;
+  Register mask = scratch1;
+  Register scratch = scratch2;
+
+  // Load the number string cache.
+  __ LoadRoot(number_string_cache, Heap::kNumberStringCacheRootIndex);
+
+  // Make the hash mask from the length of the number string cache. It
+  // contains two elements (number and string) for each cache entry.
+  __ ldr(mask, FieldMemOperand(number_string_cache, FixedArray::kLengthOffset));
+  // Divide length by two (length is not a smi).
+  __ mov(mask, Operand(mask, ASR, 1));
+  __ sub(mask, mask, Operand(1));  // Make mask.
+
+  // Calculate the entry in the number string cache. The hash value in the
+  // number string cache for smis is just the smi value.
+  __ and_(scratch, mask, Operand(object, ASR, 1));
+
+  // Calculate address of entry in string cache: each entry consists
+  // of two pointer sized fields.
+  __ add(scratch,
+         number_string_cache,
+         Operand(scratch, LSL, kPointerSizeLog2 + 1));
+
+  // Check if the entry is the smi we are looking for.
+  Register object1 = scratch1;
+  __ ldr(object1, FieldMemOperand(scratch, FixedArray::kHeaderSize));
+  __ cmp(object, object1);
+  __ b(ne, not_found);
+
+  // Get the result from the cache.
+  __ ldr(result,
+         FieldMemOperand(scratch, FixedArray::kHeaderSize + kPointerSize));
+
+  __ IncrementCounter(&Counters::number_to_string_native,
+                      1,
+                      scratch1,
+                      scratch2);
+}
+
+
+void NumberToStringStub::Generate(MacroAssembler* masm) {
+  Label runtime;
+
+  __ ldr(r1, MemOperand(sp, 0));
+
+  // Generate code to lookup number in the number string cache.
+  GenerateLookupNumberStringCache(masm, r1, r0, r2, r3, false, &runtime);
+  __ add(sp, sp, Operand(1 * kPointerSize));
+  __ Ret();
+
+  __ bind(&runtime);
+  // Handle number to string in the runtime system if not found in the cache.
+  __ TailCallRuntime(Runtime::kNumberToString, 1, 1);
+}
+
+
 // On entry r0 (rhs) and r1 (lhs) are the values to be compared.
 // On exit r0 is 0, positive or negative to indicate the result of
 // the comparison.
@@ -5503,7 +5577,7 @@ static void HandleBinaryOpSlowCases(MacroAssembler* masm,
     // sp[0] : second argument
     // sp[4] : first argument
 
-    Label not_strings, not_string1, string1;
+    Label not_strings, not_string1, string1, string1_smi2;
     __ tst(r1, Operand(kSmiTagMask));
     __ b(eq, &not_string1);
     __ CompareObjectType(r1, r2, r2, FIRST_NONSTRING_TYPE);
@@ -5511,13 +5585,24 @@ static void HandleBinaryOpSlowCases(MacroAssembler* masm,
 
     // First argument is a a string, test second.
     __ tst(r0, Operand(kSmiTagMask));
-    __ b(eq, &string1);
+    __ b(eq, &string1_smi2);
     __ CompareObjectType(r0, r2, r2, FIRST_NONSTRING_TYPE);
     __ b(ge, &string1);
 
     // First and second argument are strings.
-    StringAddStub stub(NO_STRING_CHECK_IN_STUB);
-    __ TailCallStub(&stub);
+    StringAddStub string_add_stub(NO_STRING_CHECK_IN_STUB);
+    __ TailCallStub(&string_add_stub);
+
+    __ bind(&string1_smi2);
+    // First argument is a string, second is a smi. Try to lookup the number
+    // string for the smi in the number string cache.
+    NumberToStringStub::GenerateLookupNumberStringCache(
+        masm, r0, r2, r4, r5, true, &string1);
+
+    // Replace second argument on stack and tailcall string add stub to make
+    // the result.
+    __ str(r2, MemOperand(sp, 0));
+    __ TailCallStub(&string_add_stub);
 
     // Only first argument is a string.
     __ bind(&string1);

src/arm/codegen-arm.h

@@ -660,6 +660,39 @@ class StringCompareStub: public CodeStub {
 };
 
 
+class NumberToStringStub: public CodeStub {
+ public:
+  NumberToStringStub() { }
+
+  // Generate code to do a lookup in the number string cache. If the number in
+  // the register object is found in the cache the generated code falls through
+  // with the result in the result register. The object and the result register
+  // can be the same. If the number is not found in the cache the code jumps to
+  // the label not_found with only the content of register object unchanged.
+  static void GenerateLookupNumberStringCache(MacroAssembler* masm,
+                                              Register object,
+                                              Register result,
+                                              Register scratch1,
+                                              Register scratch2,
+                                              bool object_is_smi,
+                                              Label* not_found);
+
+ private:
+  Major MajorKey() { return NumberToString; }
+  int MinorKey() { return 0; }
+
+  void Generate(MacroAssembler* masm);
+
+  const char* GetName() { return "NumberToStringStub"; }
+
+#ifdef DEBUG
+  void Print() {
+    PrintF("NumberToStringStub\n");
+  }
+#endif
+};
+
+
 } }  // namespace v8::internal
 
 #endif  // V8_ARM_CODEGEN_ARM_H_

src/x64/codegen-x64.cc

@@ -4053,8 +4053,9 @@ void CodeGenerator::GenerateNumberToString(ZoneList<Expression*>* args) {
   // Load the argument on the stack and jump to the runtime.
   Load(args->at(0));
 
-  Result answer = frame_->CallRuntime(Runtime::kNumberToString, 1);
-  frame_->Push(&answer);
+  NumberToStringStub stub;
+  Result result = frame_->CallStub(&stub, 1);
+  frame_->Push(&result);
 }
 
 
@@ -7207,6 +7208,77 @@ void RegExpExecStub::Generate(MacroAssembler* masm) {
 }
 
 
+void NumberToStringStub::GenerateLookupNumberStringCache(MacroAssembler* masm,
+                                                         Register object,
+                                                         Register result,
+                                                         Register scratch1,
+                                                         Register scratch2,
+                                                         bool object_is_smi,
+                                                         Label* not_found) {
+  // Currently only lookup for smis. Check for smi if object is not known to be
+  // a smi.
+  if (!object_is_smi) {
+    __ JumpIfNotSmi(object, not_found);
+  }
+
+  // Use of registers. Register result is used as a temporary.
+  Register number_string_cache = result;
+  Register mask = scratch1;
+  Register scratch = scratch2;
+
+  // Load the number string cache.
+  __ LoadRoot(number_string_cache, Heap::kNumberStringCacheRootIndex);
+
+  // Make the hash mask from the length of the number string cache. It
+  // contains two elements (number and string) for each cache entry.
+  __ movl(mask, FieldOperand(number_string_cache, FixedArray::kLengthOffset));
+  __ shrl(mask, Immediate(1));  // Divide length by two (length is not a smi).
+  __ subl(mask, Immediate(1));  // Make mask.
+
+  // Calculate the entry in the number string cache. The hash value in the
+  // number string cache for smis is just the smi value.
+  __ movq(scratch, object);
+  __ SmiToInteger32(scratch, scratch);
+  __ andl(scratch, mask);
+
+  // Each entry in string cache consists of two pointer sized fields,
+  // but times_twice_pointer_size (multiplication by 16) scale factor
+  // is not supported by addrmode on x64 platform.
+  // So we have to premultiply entry index before lookup
+  __ shl(scratch, Immediate(kPointerSizeLog2 + 1));
+  // Check if the entry is the smi we are looking for.
+  __ cmpq(object,
+          FieldOperand(number_string_cache,
+                       scratch,
+                       times_1,
+                       FixedArray::kHeaderSize));
+  __ j(not_equal, not_found);
+
+  // Get the result from the cache.
+  __ movq(result,
+          FieldOperand(number_string_cache,
+                       scratch,
+                       times_1,
+                       FixedArray::kHeaderSize + kPointerSize));
+  __ IncrementCounter(&Counters::number_to_string_native, 1);
+}
+
+
+void NumberToStringStub::Generate(MacroAssembler* masm) {
+  Label runtime;
+
+  __ movq(rbx, Operand(rsp, kPointerSize));
+
+  // Generate code to lookup number in the number string cache.
+  GenerateLookupNumberStringCache(masm, rbx, rax, r8, r9, false, &runtime);
+  __ ret(1 * kPointerSize);
+
+  __ bind(&runtime);
+  // Handle number to string in the runtime system if not found in the cache.
+  __ TailCallRuntime(Runtime::kNumberToString, 1, 1);
+}
+
+
 void CompareStub::Generate(MacroAssembler* masm) {
   Label call_builtin, done;
 
@@ -8794,6 +8866,7 @@ void GenericBinaryOpStub::Generate(MacroAssembler* masm) {
   // result. If arguments was passed in registers now place them on the
   // stack in the correct order below the return address.
   __ bind(&call_runtime);
+
   if (HasArgsInRegisters()) {
     __ pop(rcx);
     if (HasArgsReversed()) {
@@ -8805,48 +8878,63 @@ void GenericBinaryOpStub::Generate(MacroAssembler* masm) {
     }
     __ push(rcx);
   }
+
   switch (op_) {
     case Token::ADD: {
+      // Registers containing left and right operands respectively.
+      Register lhs, rhs;
+
+      if (HasArgsReversed()) {
+        lhs = rax;
+        rhs = rdx;
+      } else {
+        lhs = rdx;
+        rhs = rax;
+      }
+
       // Test for string arguments before calling runtime.
-      Label not_strings, both_strings, not_string1, string1;
+      Label not_strings, both_strings, not_string1, string1, string1_smi2;
       Condition is_smi;
       Result answer;
-      is_smi = masm->CheckSmi(rdx);
+      is_smi = masm->CheckSmi(lhs);
       __ j(is_smi, &not_string1);
-      __ CmpObjectType(rdx, FIRST_NONSTRING_TYPE, rdx);
+      __ CmpObjectType(lhs, FIRST_NONSTRING_TYPE, r8);
       __ j(above_equal, &not_string1);
 
       // First argument is a a string, test second.
-      is_smi = masm->CheckSmi(rax);
-      __ j(is_smi, &string1);
-      __ CmpObjectType(rax, FIRST_NONSTRING_TYPE, rax);
+      is_smi = masm->CheckSmi(rhs);
+      __ j(is_smi, &string1_smi2);
+      __ CmpObjectType(rhs, FIRST_NONSTRING_TYPE, r9);
       __ j(above_equal, &string1);
 
       // First and second argument are strings.
-      StringAddStub stub(NO_STRING_CHECK_IN_STUB);
-      __ TailCallStub(&stub);
+      StringAddStub string_add_stub(NO_STRING_CHECK_IN_STUB);
+      __ TailCallStub(&string_add_stub);
+
+      __ bind(&string1_smi2);
+      // First argument is a string, second is a smi. Try to lookup the number
+      // string for the smi in the number string cache.
+      NumberToStringStub::GenerateLookupNumberStringCache(
+          masm, rhs, rbx, rcx, r8, true, &string1);
+
+      // Replace second argument on stack and tailcall string add stub to make
+      // the result.
+      __ movq(Operand(rsp, 1 * kPointerSize), rbx);
+      __ TailCallStub(&string_add_stub);
 
       // Only first argument is a string.
       __ bind(&string1);
-      __ InvokeBuiltin(
-          HasArgsReversed() ?
-              Builtins::STRING_ADD_RIGHT :
-              Builtins::STRING_ADD_LEFT,
-          JUMP_FUNCTION);
+      __ InvokeBuiltin(Builtins::STRING_ADD_LEFT, JUMP_FUNCTION);
 
       // First argument was not a string, test second.
       __ bind(&not_string1);
-      is_smi = masm->CheckSmi(rax);
+      is_smi = masm->CheckSmi(rhs);
       __ j(is_smi, &not_strings);
-      __ CmpObjectType(rax, FIRST_NONSTRING_TYPE, rax);
+      __ CmpObjectType(rhs, FIRST_NONSTRING_TYPE, rhs);
       __ j(above_equal, &not_strings);
 
       // Only second argument is a string.
-      __ InvokeBuiltin(
-          HasArgsReversed() ?
-              Builtins::STRING_ADD_LEFT :
-              Builtins::STRING_ADD_RIGHT,
-          JUMP_FUNCTION);
+      __ InvokeBuiltin(Builtins::STRING_ADD_RIGHT, JUMP_FUNCTION);
 
       __ bind(&not_strings);
       // Neither argument is a string.

src/x64/codegen-x64.h

@@ -865,6 +865,39 @@ class StringCompareStub: public CodeStub {
 };
 
 
+class NumberToStringStub: public CodeStub {
+ public:
+  NumberToStringStub() { }
+
+  // Generate code to do a lookup in the number string cache. If the number in
+  // the register object is found in the cache the generated code falls through
+  // with the result in the result register. The object and the result register
+  // can be the same. If the number is not found in the cache the code jumps to
+  // the label not_found with only the content of register object unchanged.
+  static void GenerateLookupNumberStringCache(MacroAssembler* masm,
+                                              Register object,
+                                              Register result,
+                                              Register scratch1,
+                                              Register scratch2,
+                                              bool object_is_smi,
+                                              Label* not_found);
+
+ private:
+  Major MajorKey() { return NumberToString; }
+  int MinorKey() { return 0; }
+
+  void Generate(MacroAssembler* masm);
+
+  const char* GetName() { return "NumberToStringStub"; }
+
+#ifdef DEBUG
+  void Print() {
+    PrintF("NumberToStringStub\n");
+  }
+#endif
+};
+
+
 } }  // namespace v8::internal
 
 #endif  // V8_X64_CODEGEN_X64_H_