MIPS: DoNumberTagD performance improvement

src/mips/stub-cache-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 3828 matching lines @@
     // the value can be represented in a Smi. If not, we need to convert
     // it to a HeapNumber.
     Label box_int;
     __ Subu(t3, value, Operand(0xC0000000));  // Non-smi value gives neg result.
     __ Branch(&box_int, lt, t3, Operand(zero_reg));
     // Tag integer as smi and return it.
     __ sll(v0, value, kSmiTagSize);
     __ Ret();
 
     __ bind(&box_int);
-    // Allocate a HeapNumber for the result and perform int-to-double
-    // conversion.
-    // The arm version uses a temporary here to save r0, but we don't need to
-    // (a0 is not modified).
-    __ LoadRoot(t1, Heap::kHeapNumberMapRootIndex);
-    __ AllocateHeapNumber(v0, a3, t0, t1, &slow);
 
     if (CpuFeatures::IsSupported(FPU)) {
       CpuFeatures::Scope scope(FPU);
+      // Allocate a HeapNumber for the result and perform int-to-double
+      // conversion.
+      // The arm version uses a temporary here to save r0, but we don't need to
+      // (a0 is not modified).
+      __ LoadRoot(t1, Heap::kHeapNumberMapRootIndex);
+      __ AllocateHeapNumber(v0, a3, t0, t1, &slow, DONT_TAG_RESULT);
       __ mtc1(value, f0);
       __ cvt_d_w(f0, f0);
-      __ sdc1(f0, FieldMemOperand(v0, HeapNumber::kValueOffset));
+      __ sdc1(f0, MemOperand(v0, HeapNumber::kValueOffset));
+      __ Addu(v0, v0, kHeapObjectTag);
       __ Ret();
     } else {
+      // Allocate a HeapNumber for the result and perform int-to-double
+      // conversion.
+      // The arm version uses a temporary here to save r0, but we don't need to
+      // (a0 is not modified).
+      __ LoadRoot(t1, Heap::kHeapNumberMapRootIndex);
+      __ AllocateHeapNumber(v0, a3, t0, t1, &slow, TAG_RESULT);
       Register dst1 = t2;
       Register dst2 = t3;
       FloatingPointHelper::Destination dest =
           FloatingPointHelper::kCoreRegisters;
       FloatingPointHelper::ConvertIntToDouble(masm,
                                               value,
                                               dest,
                                               f0,
                                               dst1,
                                               dst2,
@@ skipping 16 matching lines @@
       // It can fit in an Smi.
       // Tag integer as smi and return it.
       __ sll(v0, value, kSmiTagSize);
       __ Ret();
 
       __ bind(&pl_box_int);
       // Allocate a HeapNumber for the result and perform int-to-double
       // conversion. Don't use a0 and a1 as AllocateHeapNumber clobbers all
       // registers - also when jumping due to exhausted young space.
       __ LoadRoot(t6, Heap::kHeapNumberMapRootIndex);
-      __ AllocateHeapNumber(v0, t2, t3, t6, &slow);
+      __ AllocateHeapNumber(v0, t2, t3, t6, &slow, DONT_TAG_RESULT);
 
       // This is replaced by a macro:
       // __ mtc1(value, f0);     // LS 32-bits.
       // __ mtc1(zero_reg, f1);  // MS 32-bits are all zero.
       // __ cvt_d_l(f0, f0); // Use 64 bit conv to get correct unsigned 32-bit.
 
       __ Cvt_d_uw(f0, value, f22);
 
-      __ sdc1(f0, FieldMemOperand(v0, HeapNumber::kValueOffset));
+      __ sdc1(f0, MemOperand(v0, HeapNumber::kValueOffset));
 
+      __ Addu(v0, v0, kHeapObjectTag);
       __ Ret();
     } else {
       // Check whether unsigned integer fits into smi.
       Label box_int_0, box_int_1, done;
       __ And(t2, value, Operand(0x80000000));
       __ Branch(&box_int_0, ne, t2, Operand(zero_reg));
       __ And(t2, value, Operand(0x40000000));
       __ Branch(&box_int_1, ne, t2, Operand(zero_reg));
 
       // Tag integer as smi and return it.
@@ skipping 12 matching lines @@
       // Integer has one leading zero.
       GenerateUInt2Double(masm, hiword, loword, t0, 1);
 
 
       __ bind(&done);
       // Integer was converted to double in registers hiword:loword.
       // Wrap it into a HeapNumber. Don't use a0 and a1 as AllocateHeapNumber
       // clobbers all registers - also when jumping due to exhausted young
       // space.
       __ LoadRoot(t6, Heap::kHeapNumberMapRootIndex);
-      __ AllocateHeapNumber(t2, t3, t5, t6, &slow);
+      __ AllocateHeapNumber(t2, t3, t5, t6, &slow, TAG_RESULT);
 
       __ sw(hiword, FieldMemOperand(t2, HeapNumber::kExponentOffset));
       __ sw(loword, FieldMemOperand(t2, HeapNumber::kMantissaOffset));
 
       __ mov(v0, t2);
       __ Ret();
     }
   } else if (elements_kind == EXTERNAL_FLOAT_ELEMENTS) {
     // For the floating-point array type, we need to always allocate a
     // HeapNumber.
     if (CpuFeatures::IsSupported(FPU)) {
       CpuFeatures::Scope scope(FPU);
       // Allocate a HeapNumber for the result. Don't use a0 and a1 as
       // AllocateHeapNumber clobbers all registers - also when jumping due to
       // exhausted young space.
       __ LoadRoot(t6, Heap::kHeapNumberMapRootIndex);
-      __ AllocateHeapNumber(v0, t3, t5, t6, &slow);
+      __ AllocateHeapNumber(v0, t3, t5, t6, &slow, DONT_TAG_RESULT);
       // The float (single) value is already in fpu reg f0 (if we use float).
       __ cvt_d_s(f0, f0);
-      __ sdc1(f0, FieldMemOperand(v0, HeapNumber::kValueOffset));
+      __ sdc1(f0, MemOperand(v0, HeapNumber::kValueOffset));
+
+      __ Addu(v0, v0, kHeapObjectTag);
       __ Ret();
     } else {
       // Allocate a HeapNumber for the result. Don't use a0 and a1 as
       // AllocateHeapNumber clobbers all registers - also when jumping due to
       // exhausted young space.
       __ LoadRoot(t6, Heap::kHeapNumberMapRootIndex);
-      __ AllocateHeapNumber(v0, t3, t5, t6, &slow);
+      __ AllocateHeapNumber(v0, t3, t5, t6, &slow, TAG_RESULT);
       // FPU is not available, do manual single to double conversion.
 
       // a2: floating point value (binary32).
       // v0: heap number for result
 
       // Extract mantissa to t4.
       __ And(t4, value, Operand(kBinary32MantissaMask));
 
       // Extract exponent to t5.
       __ srl(t5, value, kBinary32MantissaBits);
@@ skipping 34 matching lines @@
       __ Ret();
     }
 
   } else if (elements_kind == EXTERNAL_DOUBLE_ELEMENTS) {
     if (CpuFeatures::IsSupported(FPU)) {
       CpuFeatures::Scope scope(FPU);
       // Allocate a HeapNumber for the result. Don't use a0 and a1 as
       // AllocateHeapNumber clobbers all registers - also when jumping due to
       // exhausted young space.
       __ LoadRoot(t6, Heap::kHeapNumberMapRootIndex);
-      __ AllocateHeapNumber(v0, t3, t5, t6, &slow);
+      __ AllocateHeapNumber(v0, t3, t5, t6, &slow, DONT_TAG_RESULT);
       // The double value is already in f0
-      __ sdc1(f0, FieldMemOperand(v0, HeapNumber::kValueOffset));
+      __ sdc1(f0, MemOperand(v0, HeapNumber::kValueOffset));
+
+      __ Addu(v0, v0, kHeapObjectTag);
       __ Ret();
     } else {
       // Allocate a HeapNumber for the result. Don't use a0 and a1 as
       // AllocateHeapNumber clobbers all registers - also when jumping due to
       // exhausted young space.
       __ LoadRoot(t6, Heap::kHeapNumberMapRootIndex);
-      __ AllocateHeapNumber(v0, t3, t5, t6, &slow);
+      __ AllocateHeapNumber(v0, t3, t5, t6, &slow, TAG_RESULT);
 
       __ sw(a2, FieldMemOperand(v0, HeapNumber::kMantissaOffset));
       __ sw(a3, FieldMemOperand(v0, HeapNumber::kExponentOffset));
       __ Ret();
     }
 
   } else {
     // Tag integer as smi and return it.
     __ sll(v0, value, kSmiTagSize);
     __ Ret();
@@ skipping 497 matching lines @@
   // Load the upper word of the double in the fixed array and test for NaN.
   __ sll(scratch2, key_reg, kDoubleSizeLog2 - kSmiTagSize);
   __ Addu(indexed_double_offset, elements_reg, Operand(scratch2));
   uint32_t upper_32_offset = FixedArray::kHeaderSize + sizeof(kHoleNanLower32);
   __ lw(scratch, FieldMemOperand(indexed_double_offset, upper_32_offset));
   __ Branch(&miss_force_generic, eq, scratch, Operand(kHoleNanUpper32));
 
   // Non-NaN. Allocate a new heap number and copy the double value into it.
   __ LoadRoot(heap_number_map, Heap::kHeapNumberMapRootIndex);
   __ AllocateHeapNumber(heap_number_reg, scratch2, scratch3,
-                        heap_number_map, &slow_allocate_heapnumber);
+                        heap_number_map, &slow_allocate_heapnumber, TAG_RESULT);
 
   // Don't need to reload the upper 32 bits of the double, it's already in
   // scratch.
   __ sw(scratch, FieldMemOperand(heap_number_reg,
                                  HeapNumber::kExponentOffset));
   __ lw(scratch, FieldMemOperand(indexed_double_offset,
                                  FixedArray::kHeaderSize));
   __ sw(scratch, FieldMemOperand(heap_number_reg,
                                  HeapNumber::kMantissaOffset));
 
@@ skipping 319 matching lines @@
     __ Jump(ic_slow, RelocInfo::CODE_TARGET);
   }
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS