Out-of-line constant pool on Arm: Stage 1 - Free up r7 for use as constant pool pointer register

src/arm/stub-cache-arm.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 852 matching lines @@
 
   // Pass the additional arguments.
   Handle<CallHandlerInfo> api_call_info = optimization.api_call_info();
   Handle<Object> call_data(api_call_info->data(), masm->isolate());
   if (masm->isolate()->heap()->InNewSpace(*call_data)) {
     __ Move(r0, api_call_info);
     __ ldr(r6, FieldMemOperand(r0, CallHandlerInfo::kDataOffset));
   } else {
     __ Move(r6, call_data);
   }
-  __ mov(r7, Operand(ExternalReference::isolate_address(masm->isolate())));
+  __ mov(ip, Operand(ExternalReference::isolate_address(masm->isolate())));

[ulan, 2013/07/30 09:45:19]

This mov might use ip internally.

   // Store JS function, call data, isolate ReturnValue default and ReturnValue.
-  __ stm(ib, sp, r5.bit() | r6.bit() | r7.bit());
+  __ stm(ib, sp, r5.bit() | r6.bit() | ip.bit());
   __ LoadRoot(r5, Heap::kUndefinedValueRootIndex);
   __ str(r5, MemOperand(sp, 4 * kPointerSize));
   __ str(r5, MemOperand(sp, 5 * kPointerSize));
 
   // Prepare arguments.
   __ add(r2, sp, Operand(5 * kPointerSize));
 
   // Allocate the v8::Arguments structure in the arguments' space since
   // it's not controlled by GC.
   const int kApiStackSpace = 4;
@@ skipping 937 matching lines @@
       // Check for a smi.
       __ Drop(argc + 1);
       __ Ret();
 
       __ bind(&with_write_barrier);
 
       __ ldr(r3, FieldMemOperand(receiver, HeapObject::kMapOffset));
 
       if (FLAG_smi_only_arrays  && !FLAG_trace_elements_transitions) {
         Label fast_object, not_fast_object;
-        __ CheckFastObjectElements(r3, r7, &not_fast_object);
+        __ CheckFastObjectElements(r3, r9, &not_fast_object);
         __ jmp(&fast_object);
         // In case of fast smi-only, convert to fast object, otherwise bail out.
         __ bind(&not_fast_object);
-        __ CheckFastSmiElements(r3, r7, &call_builtin);
+        __ CheckFastSmiElements(r3, r9, &call_builtin);
 
-        __ ldr(r7, FieldMemOperand(r4, HeapObject::kMapOffset));
+        __ ldr(r9, FieldMemOperand(r4, HeapObject::kMapOffset));
         __ LoadRoot(ip, Heap::kHeapNumberMapRootIndex);
-        __ cmp(r7, ip);
+        __ cmp(r9, ip);
         __ b(eq, &call_builtin);
         // edx: receiver
         // r3: map
         Label try_holey_map;
         __ LoadTransitionedArrayMapConditional(FAST_SMI_ELEMENTS,
                                                FAST_ELEMENTS,
                                                r3,
-                                               r7,
+                                               r9,
                                                &try_holey_map);
         __ mov(r2, receiver);
         ElementsTransitionGenerator::
             GenerateMapChangeElementsTransition(masm(),
                                                 DONT_TRACK_ALLOCATION_SITE,
                                                 NULL);
         __ jmp(&fast_object);
 
         __ bind(&try_holey_map);
         __ LoadTransitionedArrayMapConditional(FAST_HOLEY_SMI_ELEMENTS,
                                                FAST_HOLEY_ELEMENTS,
                                                r3,
-                                               r7,
+                                               r9,
                                                &call_builtin);
         __ mov(r2, receiver);
         ElementsTransitionGenerator::
             GenerateMapChangeElementsTransition(masm(),
                                                 DONT_TRACK_ALLOCATION_SITE,
                                                 NULL);
         __ bind(&fast_object);
       } else {
         __ CheckFastObjectElements(r3, r3, &call_builtin);
       }
@@ skipping 12 matching lines @@
                      r4,
                      kLRHasNotBeenSaved,
                      kDontSaveFPRegs,
                      EMIT_REMEMBERED_SET,
                      OMIT_SMI_CHECK);
       __ Drop(argc + 1);
       __ Ret();
 
       __ bind(&attempt_to_grow_elements);
       // r0: array's length + 1.
-      // r4: elements' length.
 
       if (!FLAG_inline_new) {
         __ b(&call_builtin);
       }
 
       __ ldr(r2, MemOperand(sp, (argc - 1) * kPointerSize));
       // Growing elements that are SMI-only requires special handling in case
       // the new element is non-Smi. For now, delegate to the builtin.
       Label no_fast_elements_check;
       __ JumpIfSmi(r2, &no_fast_elements_check);
-      __ ldr(r7, FieldMemOperand(receiver, HeapObject::kMapOffset));
-      __ CheckFastObjectElements(r7, r7, &call_builtin);
+      __ ldr(r9, FieldMemOperand(receiver, HeapObject::kMapOffset));
+      __ CheckFastObjectElements(r9, r9, &call_builtin);
       __ bind(&no_fast_elements_check);
 
       ExternalReference new_space_allocation_top =
           ExternalReference::new_space_allocation_top_address(isolate());
       ExternalReference new_space_allocation_limit =
           ExternalReference::new_space_allocation_limit_address(isolate());
 
       const int kAllocationDelta = 4;
       // Load top and check if it is the end of elements.
       __ add(end_elements, elements, Operand::PointerOffsetFromSmiKey(r0));
       __ add(end_elements, end_elements, Operand(kEndElementsOffset));
-      __ mov(r7, Operand(new_space_allocation_top));
-      __ ldr(r3, MemOperand(r7));
+      __ mov(r4, Operand(new_space_allocation_top));
+      __ ldr(r3, MemOperand(r4));
       __ cmp(end_elements, r3);
       __ b(ne, &call_builtin);
 
       __ mov(r9, Operand(new_space_allocation_limit));
       __ ldr(r9, MemOperand(r9));
       __ add(r3, r3, Operand(kAllocationDelta * kPointerSize));
       __ cmp(r3, r9);
       __ b(hi, &call_builtin);
 
       // We fit and could grow elements.
       // Update new_space_allocation_top.
-      __ str(r3, MemOperand(r7));
+      __ str(r3, MemOperand(r4));
       // Push the argument.
       __ str(r2, MemOperand(end_elements));
       // Fill the rest with holes.
       __ LoadRoot(r3, Heap::kTheHoleValueRootIndex);
       for (int i = 1; i < kAllocationDelta; i++) {
         __ str(r3, MemOperand(end_elements, i * kPointerSize));
       }
 
       // Update elements' and array's sizes.
       __ str(r0, FieldMemOperand(receiver, JSArray::kLengthOffset));
+      __ ldr(r4, FieldMemOperand(elements, FixedArray::kLengthOffset));
       __ add(r4, r4, Operand(Smi::FromInt(kAllocationDelta)));
       __ str(r4, FieldMemOperand(elements, FixedArray::kLengthOffset));
 
       // Elements are in new space, so write barrier is not required.
       __ Drop(argc + 1);
       __ Ret();
     }
     __ bind(&call_builtin);
     __ TailCallExternalReference(
         ExternalReference(Builtins::c_ArrayPush, isolate()), argc + 1, 1);
@@ skipping 1321 matching lines @@
     case EXTERNAL_UNSIGNED_SHORT_ELEMENTS:
       __ strh(r5, MemOperand(r3, key, LSL, 0));
       break;
     case EXTERNAL_INT_ELEMENTS:
     case EXTERNAL_UNSIGNED_INT_ELEMENTS:
       __ str(r5, MemOperand(r3, key, LSL, 1));
       break;
     case EXTERNAL_FLOAT_ELEMENTS:
       // Perform int-to-float conversion and store to memory.
       __ SmiUntag(r4, key);
-      StoreIntAsFloat(masm, r3, r4, r5, r7);
+      StoreIntAsFloat(masm, r3, r4, r5, r6);
       break;
     case EXTERNAL_DOUBLE_ELEMENTS:
       __ vmov(s2, r5);
       __ vcvt_f64_s32(d0, s2);
       __ add(r3, r3, Operand(key, LSL, 2));
       // r3: effective address of the double element
       __ vstr(d0, r3, 0);
       break;
     case FAST_ELEMENTS:
     case FAST_SMI_ELEMENTS:
@@ skipping 35 matching lines @@
     } else if (elements_kind == EXTERNAL_DOUBLE_ELEMENTS) {
       __ sub(r5, r0, Operand(kHeapObjectTag));
       __ vldr(d0, r5, HeapNumber::kValueOffset);
       __ add(r5, r3, Operand(key, LSL, 2));
       __ vstr(d0, r5, 0);
     } else {
       // Hoisted load.  vldr requires offset to be a multiple of 4 so we can
       // not include -kHeapObjectTag into it.
       __ sub(r5, value, Operand(kHeapObjectTag));
       __ vldr(d0, r5, HeapNumber::kValueOffset);
-      __ ECMAToInt32(r5, d0, r6, r7, r9, d1);
+      __ ECMAToInt32(r5, d0, r4, r6, r9, d1);
 
       switch (elements_kind) {
         case EXTERNAL_BYTE_ELEMENTS:
         case EXTERNAL_UNSIGNED_BYTE_ELEMENTS:
           __ strb(r5, MemOperand(r3, key, LSR, 1));
           break;
         case EXTERNAL_SHORT_ELEMENTS:
         case EXTERNAL_UNSIGNED_SHORT_ELEMENTS:
           __ strh(r5, MemOperand(r3, key, LSL, 0));
           break;
@@ skipping 216 matching lines @@
   //  -- r5    : scratch
   // -----------------------------------
   Label miss_force_generic, transition_elements_kind, grow, slow;
   Label finish_store, check_capacity;
 
   Register value_reg = r0;
   Register key_reg = r1;
   Register receiver_reg = r2;
   Register elements_reg = r3;
   Register scratch1 = r4;
-  Register scratch2 = r5;
-  Register length_reg = r7;
+  Register scratch2 = no_reg;  // Will be r5.
+  Register length_reg = r5;
 
   // This stub is meant to be tail-jumped to, the receiver must already
   // have been verified by the caller to not be a smi.
 
   // Check that the key is a smi or a heap number convertible to a smi.
   GenerateSmiKeyCheck(masm, key_reg, r4, d1, d2, &miss_force_generic);
 
   __ ldr(elements_reg,
          FieldMemOperand(receiver_reg, JSObject::kElementsOffset));
 
@@ skipping 43 matching lines @@
 
     // Check for the empty array, and preallocate a small backing store if
     // possible.
     __ ldr(length_reg,
            FieldMemOperand(receiver_reg, JSArray::kLengthOffset));
     __ ldr(elements_reg,
            FieldMemOperand(receiver_reg, JSObject::kElementsOffset));
     __ CompareRoot(elements_reg, Heap::kEmptyFixedArrayRootIndex);
     __ b(ne, &check_capacity);
 
+    scratch2 = length_reg;  // Use length_reg as scratch2 here.
+
     int size = FixedDoubleArray::SizeFor(JSArray::kPreallocatedArrayElements);
     __ Allocate(size, elements_reg, scratch1, scratch2, &slow, TAG_OBJECT);
 
     // Initialize the new FixedDoubleArray.
     __ LoadRoot(scratch1, Heap::kFixedDoubleArrayMapRootIndex);
     __ str(scratch1, FieldMemOperand(elements_reg, JSObject::kMapOffset));
     __ mov(scratch1,
            Operand(Smi::FromInt(JSArray::kPreallocatedArrayElements)));
     __ str(scratch1,
            FieldMemOperand(elements_reg, FixedDoubleArray::kLengthOffset));
 
     __ mov(scratch1, elements_reg);
     __ StoreNumberToDoubleElements(value_reg, key_reg, scratch1,
                                    scratch2, &transition_elements_kind);
 
     __ mov(scratch1, Operand(kHoleNanLower32));
     __ mov(scratch2, Operand(kHoleNanUpper32));
     for (int i = 1; i < JSArray::kPreallocatedArrayElements; i++) {
       int offset = FixedDoubleArray::OffsetOfElementAt(i);
       __ str(scratch1, FieldMemOperand(elements_reg, offset));
       __ str(scratch2, FieldMemOperand(elements_reg, offset + kPointerSize));
     }
 
+    scratch2 = no_reg;  // End of scratch2's live range.
+
     // Install the new backing store in the JSArray.
     __ str(elements_reg,
            FieldMemOperand(receiver_reg, JSObject::kElementsOffset));
     __ RecordWriteField(receiver_reg, JSObject::kElementsOffset, elements_reg,
                         scratch1, kLRHasNotBeenSaved, kDontSaveFPRegs,
                         EMIT_REMEMBERED_SET, OMIT_SMI_CHECK);
 
     // Increment the length of the array.
     __ mov(length_reg, Operand(Smi::FromInt(1)));
     __ str(length_reg, FieldMemOperand(receiver_reg, JSArray::kLengthOffset));
@@ skipping 17 matching lines @@
     TailCallBuiltin(masm, Builtins::kKeyedStoreIC_Slow);
   }
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM