ARM: Load the heap number map into a register and keep it...

src/arm/codegen-arm.cc

 // Copyright 2010 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 4688 matching lines @@
 
 
 void CodeGenerator::GenerateRandomHeapNumber(
     ZoneList<Expression*>* args) {
   VirtualFrame::SpilledScope spilled_scope(frame_);
   ASSERT(args->length() == 0);
 
   Label slow_allocate_heapnumber;
   Label heapnumber_allocated;
 
-  __ AllocateHeapNumber(r4, r1, r2, &slow_allocate_heapnumber);
+  __ LoadRoot(r6, Heap::kHeapNumberMapRootIndex);
+  __ AllocateHeapNumber(r4, r1, r2, r6, &slow_allocate_heapnumber);
   __ jmp(&heapnumber_allocated);
 
   __ bind(&slow_allocate_heapnumber);
   // To allocate a heap number, and ensure that it is not a smi, we
   // call the runtime function FUnaryMinus on 0, returning the double
   // -0.0. A new, distinct heap number is returned each time.
   __ mov(r0, Operand(Smi::FromInt(0)));
   __ push(r0);
   __ CallRuntime(Runtime::kNumberUnaryMinus, 1);
   __ mov(r4, Operand(r0));
@@ skipping 2636 matching lines @@
 void GenericBinaryOpStub::HandleBinaryOpSlowCases(
     MacroAssembler* masm,
     Label* not_smi,
     Register lhs,
     Register rhs,
     const Builtins::JavaScript& builtin) {
   Label slow, slow_reverse, do_the_call;
   bool use_fp_registers = CpuFeatures::IsSupported(VFP3) && Token::MOD != op_;
 
   ASSERT((lhs.is(r0) && rhs.is(r1)) || (lhs.is(r1) && rhs.is(r0)));
+  Register heap_number_map = r6;
 
   if (ShouldGenerateSmiCode()) {
+    __ LoadRoot(heap_number_map, Heap::kHeapNumberMapRootIndex);
+
     // Smi-smi case (overflow).
     // Since both are Smis there is no heap number to overwrite, so allocate.
-    // The new heap number is in r5.  r6 and r7 are scratch.
-    __ AllocateHeapNumber(r5, r6, r7, lhs.is(r0) ? &slow_reverse : &slow);
+    // The new heap number is in r5.  r3 and r7 are scratch.
+    __ AllocateHeapNumber(
+        r5, r3, r7, heap_number_map, lhs.is(r0) ? &slow_reverse : &slow);
 
     // If we have floating point hardware, inline ADD, SUB, MUL, and DIV,
     // using registers d7 and d6 for the double values.
     if (use_fp_registers) {
       CpuFeatures::Scope scope(VFP3);
       __ mov(r7, Operand(rhs, ASR, kSmiTagSize));
       __ vmov(s15, r7);
       __ vcvt_f64_s32(d7, s15);
       __ mov(r7, Operand(lhs, ASR, kSmiTagSize));
       __ vmov(s13, r7);
       __ vcvt_f64_s32(d6, s13);
     } else {
-      // Write Smi from rhs to r3 and r2 in double format.  r6 is scratch.
+      // Write Smi from rhs to r3 and r2 in double format.  r3 is scratch.
       __ mov(r7, Operand(rhs));
-      ConvertToDoubleStub stub1(r3, r2, r7, r6);
+      ConvertToDoubleStub stub1(r3, r2, r7, r9);
       __ push(lr);
       __ Call(stub1.GetCode(), RelocInfo::CODE_TARGET);
-      // Write Smi from lhs to r1 and r0 in double format.  r6 is scratch.
+      // Write Smi from lhs to r1 and r0 in double format.  r9 is scratch.
       __ mov(r7, Operand(lhs));
-      ConvertToDoubleStub stub2(r1, r0, r7, r6);
+      ConvertToDoubleStub stub2(r1, r0, r7, r9);
       __ Call(stub2.GetCode(), RelocInfo::CODE_TARGET);
       __ pop(lr);
     }
     __ jmp(&do_the_call);  // Tail call.  No return.
   }
 
   // We branch here if at least one of r0 and r1 is not a Smi.
   __ bind(not_smi);
+  __ LoadRoot(heap_number_map, Heap::kHeapNumberMapRootIndex);
 
   // After this point we have the left hand side in r1 and the right hand side
   // in r0.
   if (lhs.is(r0)) {
     __ Swap(r0, r1, ip);
   }
 
   if (ShouldGenerateFPCode()) {
     Label r0_is_smi, r1_is_smi, finished_loading_r0, finished_loading_r1;
 
     if (runtime_operands_type_ == BinaryOpIC::DEFAULT) {
       switch (op_) {
         case Token::ADD:
         case Token::SUB:
         case Token::MUL:
         case Token::DIV:
           GenerateTypeTransition(masm);
           break;
 
         default:
           break;
       }
+      // Restore heap number map register.
+      __ LoadRoot(heap_number_map, Heap::kHeapNumberMapRootIndex);
     }
 
     if (mode_ == NO_OVERWRITE) {
       // In the case where there is no chance of an overwritable float we may as
       // well do the allocation immediately while r0 and r1 are untouched.
-      __ AllocateHeapNumber(r5, r6, r7, &slow);
+      __ AllocateHeapNumber(r5, r3, r7, heap_number_map, &slow);
     }
 
     // Move r0 to a double in r2-r3.
     __ tst(r0, Operand(kSmiTagMask));
     __ b(eq, &r0_is_smi);  // It's a Smi so don't check it's a heap number.
-    __ CompareObjectType(r0, r4, r4, HEAP_NUMBER_TYPE);
+    __ ldr(r4, FieldMemOperand(r0, HeapObject::kMapOffset));
+    __ AssertRegisterIsRoot(heap_number_map, Heap::kHeapNumberMapRootIndex);
+    __ cmp(r4, heap_number_map);
     __ b(ne, &slow);
     if (mode_ == OVERWRITE_RIGHT) {
       __ mov(r5, Operand(r0));  // Overwrite this heap number.
     }
     if (use_fp_registers) {
       CpuFeatures::Scope scope(VFP3);
       // Load the double from tagged HeapNumber r0 to d7.
       __ sub(r7, r0, Operand(kHeapObjectTag));
       __ vldr(d7, r7, HeapNumber::kValueOffset);
     } else {
       // Calling convention says that second double is in r2 and r3.
       __ Ldrd(r2, r3, FieldMemOperand(r0, HeapNumber::kValueOffset));
     }
     __ jmp(&finished_loading_r0);
     __ bind(&r0_is_smi);
     if (mode_ == OVERWRITE_RIGHT) {
       // We can't overwrite a Smi so get address of new heap number into r5.
-    __ AllocateHeapNumber(r5, r6, r7, &slow);
+    __ AllocateHeapNumber(r5, r4, r7, heap_number_map, &slow);
     }
 
     if (use_fp_registers) {
       CpuFeatures::Scope scope(VFP3);
       // Convert smi in r0 to double in d7.
       __ mov(r7, Operand(r0, ASR, kSmiTagSize));
       __ vmov(s15, r7);
       __ vcvt_f64_s32(d7, s15);
     } else {
       // Write Smi from r0 to r3 and r2 in double format.
       __ mov(r7, Operand(r0));
-      ConvertToDoubleStub stub3(r3, r2, r7, r6);
+      ConvertToDoubleStub stub3(r3, r2, r7, r4);
       __ push(lr);
       __ Call(stub3.GetCode(), RelocInfo::CODE_TARGET);
       __ pop(lr);
     }
 
     // HEAP_NUMBERS stub is slower than GENERIC on a pair of smis.
     // r0 is known to be a smi. If r1 is also a smi then switch to GENERIC.
     Label r1_is_not_smi;
     if (runtime_operands_type_ == BinaryOpIC::HEAP_NUMBERS) {
       __ tst(r1, Operand(kSmiTagMask));
       __ b(ne, &r1_is_not_smi);
       GenerateTypeTransition(masm);
+      // Restore heap number map register.
+      __ LoadRoot(heap_number_map, Heap::kHeapNumberMapRootIndex);
       __ jmp(&r1_is_smi);
     }
 
     __ bind(&finished_loading_r0);
 
     // Move r1 to a double in r0-r1.
     __ tst(r1, Operand(kSmiTagMask));
     __ b(eq, &r1_is_smi);  // It's a Smi so don't check it's a heap number.
     __ bind(&r1_is_not_smi);
-    __ CompareObjectType(r1, r4, r4, HEAP_NUMBER_TYPE);
+    __ ldr(r4, FieldMemOperand(r1, HeapNumber::kMapOffset));
+    __ AssertRegisterIsRoot(heap_number_map, Heap::kHeapNumberMapRootIndex);
+    __ cmp(r4, heap_number_map);
     __ b(ne, &slow);
     if (mode_ == OVERWRITE_LEFT) {
       __ mov(r5, Operand(r1));  // Overwrite this heap number.
     }
     if (use_fp_registers) {
       CpuFeatures::Scope scope(VFP3);
       // Load the double from tagged HeapNumber r1 to d6.
       __ sub(r7, r1, Operand(kHeapObjectTag));
       __ vldr(d6, r7, HeapNumber::kValueOffset);
     } else {
       // Calling convention says that first double is in r0 and r1.
       __ Ldrd(r0, r1, FieldMemOperand(r1, HeapNumber::kValueOffset));
     }
     __ jmp(&finished_loading_r1);
     __ bind(&r1_is_smi);
     if (mode_ == OVERWRITE_LEFT) {
       // We can't overwrite a Smi so get address of new heap number into r5.
-    __ AllocateHeapNumber(r5, r6, r7, &slow);
+    __ AllocateHeapNumber(r5, r4, r7, heap_number_map, &slow);
     }
 
     if (use_fp_registers) {
       CpuFeatures::Scope scope(VFP3);
       // Convert smi in r1 to double in d6.
       __ mov(r7, Operand(r1, ASR, kSmiTagSize));
       __ vmov(s13, r7);
       __ vcvt_f64_s32(d6, s13);
     } else {
       // Write Smi from r1 to r1 and r0 in double format.
       __ mov(r7, Operand(r1));
-      ConvertToDoubleStub stub4(r1, r0, r7, r6);
+      ConvertToDoubleStub stub4(r1, r0, r7, r9);
       __ push(lr);
       __ Call(stub4.GetCode(), RelocInfo::CODE_TARGET);
       __ pop(lr);
     }
 
     __ bind(&finished_loading_r1);
 
     __ bind(&do_the_call);
     // If we are inlining the operation using VFP3 instructions for
     // add, subtract, multiply, or divide, the arguments are in d6 and d7.
@@ skipping 40 matching lines @@
   #else
       // Double returned in registers 0 and 1.
       __ Strd(r0, r1, FieldMemOperand(r5, HeapNumber::kValueOffset));
   #endif
       __ mov(r0, Operand(r5));
       // And we are done.
       __ pop(pc);
     }
   }
 
-
   if (lhs.is(r0)) {
     __ b(&slow);
     __ bind(&slow_reverse);
     __ Swap(r0, r1, ip);
   }
 
+  heap_number_map = no_reg;  // Don't use this any more from here on.
+
   // We jump to here if something goes wrong (one param is not a number of any
   // sort or new-space allocation fails).
   __ bind(&slow);
 
   // Push arguments to the stack
   __ Push(r1, r0);
 
   if (Token::ADD == op_) {
     // Test for string arguments before calling runtime.
     // r1 : first argument
@@ skipping 145 matching lines @@
 // result is a Smi.  If so, great, otherwise we try to find a heap number to
 // write the answer into (either by allocating or by overwriting).
 // On entry the operands are in lhs and rhs.  On exit the answer is in r0.
 void GenericBinaryOpStub::HandleNonSmiBitwiseOp(MacroAssembler* masm,
                                                 Register lhs,
                                                 Register rhs) {
   Label slow, result_not_a_smi;
   Label rhs_is_smi, lhs_is_smi;
   Label done_checking_rhs, done_checking_lhs;
 
+  Register heap_number_map = r6;
+  __ LoadRoot(heap_number_map, Heap::kHeapNumberMapRootIndex);
+
   __ tst(lhs, Operand(kSmiTagMask));
   __ b(eq, &lhs_is_smi);  // It's a Smi so don't check it's a heap number.
-  __ CompareObjectType(lhs, r4, r4, HEAP_NUMBER_TYPE);
+  __ ldr(r4, FieldMemOperand(lhs, HeapNumber::kMapOffset));
+  __ cmp(r4, heap_number_map);
   __ b(ne, &slow);
   GetInt32(masm, lhs, r3, r5, r4, &slow);
   __ jmp(&done_checking_lhs);
   __ bind(&lhs_is_smi);
   __ mov(r3, Operand(lhs, ASR, 1));
   __ bind(&done_checking_lhs);
 
   __ tst(rhs, Operand(kSmiTagMask));
   __ b(eq, &rhs_is_smi);  // It's a Smi so don't check it's a heap number.
-  __ CompareObjectType(rhs, r4, r4, HEAP_NUMBER_TYPE);
+  __ ldr(r4, FieldMemOperand(rhs, HeapNumber::kMapOffset));
+  __ cmp(r4, heap_number_map);
   __ b(ne, &slow);
   GetInt32(masm, rhs, r2, r5, r4, &slow);
   __ jmp(&done_checking_rhs);
   __ bind(&rhs_is_smi);
   __ mov(r2, Operand(rhs, ASR, 1));
   __ bind(&done_checking_rhs);
 
   ASSERT(((lhs.is(r0) && rhs.is(r1)) || (lhs.is(r1) && rhs.is(r0))));
 
   // r0 and r1: Original operands (Smi or heap numbers).
@@ skipping 39 matching lines @@
       __ mov(r5, Operand(rhs));
       break;
     }
     case OVERWRITE_LEFT: {
       __ tst(lhs, Operand(kSmiTagMask));
       __ b(eq, &have_to_allocate);
       __ mov(r5, Operand(lhs));
       break;
     }
     case NO_OVERWRITE: {
-      // Get a new heap number in r5.  r6 and r7 are scratch.
-      __ AllocateHeapNumber(r5, r6, r7, &slow);
+      // Get a new heap number in r5.  r4 and r7 are scratch.
+      __ AllocateHeapNumber(r5, r4, r7, heap_number_map, &slow);
     }
     default: break;
   }
   __ bind(&got_a_heap_number);
   // r2: Answer as signed int32.
   // r5: Heap number to write answer into.
 
   // Nothing can go wrong now, so move the heap number to r0, which is the
   // result.
   __ mov(r0, Operand(r5));
 
   // Tail call that writes the int32 in r2 to the heap number in r0, using
   // r3 as scratch.  r0 is preserved and returned.
   WriteInt32ToHeapNumberStub stub(r2, r0, r3);
   __ Jump(stub.GetCode(), RelocInfo::CODE_TARGET);
 
   if (mode_ != NO_OVERWRITE) {
     __ bind(&have_to_allocate);
-    // Get a new heap number in r5.  r6 and r7 are scratch.
-    __ AllocateHeapNumber(r5, r6, r7, &slow);
+    // Get a new heap number in r5.  r4 and r7 are scratch.
+    __ AllocateHeapNumber(r5, r4, r7, heap_number_map, &slow);
     __ jmp(&got_a_heap_number);
   }
 
   // If all else failed then we go to the runtime system.
   __ bind(&slow);
   __ Push(lhs, rhs);  // Restore stack.
   switch (op_) {
     case Token::BIT_OR:
       __ InvokeBuiltin(Builtins::BIT_OR, JUMP_JS);
       break;
@@ skipping 550 matching lines @@
   __ push(r0);
   __ TailCallRuntime(Runtime::kStackGuard, 1, 1);
 
   __ StubReturn(1);
 }
 
 
 void GenericUnaryOpStub::Generate(MacroAssembler* masm) {
   Label slow, done;
 
+  Register heap_number_map = r6;
+  __ LoadRoot(heap_number_map, Heap::kHeapNumberMapRootIndex);
+
   if (op_ == Token::SUB) {
     // Check whether the value is a smi.
     Label try_float;
     __ tst(r0, Operand(kSmiTagMask));
     __ b(ne, &try_float);
 
     // Go slow case if the value of the expression is zero
     // to make sure that we switch between 0 and -0.
     __ cmp(r0, Operand(0));
     __ b(eq, &slow);
 
     // The value of the expression is a smi that is not zero.  Try
     // optimistic subtraction '0 - value'.
     __ rsb(r1, r0, Operand(0), SetCC);
     __ b(vs, &slow);
 
     __ mov(r0, Operand(r1));  // Set r0 to result.
     __ b(&done);
 
     __ bind(&try_float);
-    __ CompareObjectType(r0, r1, r1, HEAP_NUMBER_TYPE);
+    __ ldr(r1, FieldMemOperand(r0, HeapObject::kMapOffset));
+    __ AssertRegisterIsRoot(heap_number_map, Heap::kHeapNumberMapRootIndex);
+    __ cmp(r1, heap_number_map);
     __ b(ne, &slow);
     // r0 is a heap number.  Get a new heap number in r1.
     if (overwrite_) {
       __ ldr(r2, FieldMemOperand(r0, HeapNumber::kExponentOffset));
       __ eor(r2, r2, Operand(HeapNumber::kSignMask));  // Flip sign.
       __ str(r2, FieldMemOperand(r0, HeapNumber::kExponentOffset));
     } else {
-      __ AllocateHeapNumber(r1, r2, r3, &slow);
+      __ AllocateHeapNumber(r1, r2, r3, r6, &slow);
       __ ldr(r3, FieldMemOperand(r0, HeapNumber::kMantissaOffset));
       __ ldr(r2, FieldMemOperand(r0, HeapNumber::kExponentOffset));
       __ str(r3, FieldMemOperand(r1, HeapNumber::kMantissaOffset));
       __ eor(r2, r2, Operand(HeapNumber::kSignMask));  // Flip sign.
       __ str(r2, FieldMemOperand(r1, HeapNumber::kExponentOffset));
       __ mov(r0, Operand(r1));
     }
   } else if (op_ == Token::BIT_NOT) {
     // Check if the operand is a heap number.
-    __ CompareObjectType(r0, r1, r1, HEAP_NUMBER_TYPE);
+    __ ldr(r1, FieldMemOperand(r0, HeapObject::kMapOffset));
+    __ AssertRegisterIsRoot(heap_number_map, Heap::kHeapNumberMapRootIndex);
+    __ cmp(r1, heap_number_map);
     __ b(ne, &slow);
 
     // Convert the heap number is r0 to an untagged integer in r1.
     GetInt32(masm, r0, r1, r2, r3, &slow);
 
     // Do the bitwise operation (move negated) and check if the result
     // fits in a smi.
     Label try_float;
     __ mvn(r1, Operand(r1));
     __ add(r2, r1, Operand(0x40000000), SetCC);
     __ b(mi, &try_float);
     __ mov(r0, Operand(r1, LSL, kSmiTagSize));
     __ b(&done);
 
     __ bind(&try_float);
     if (!overwrite_) {
       // Allocate a fresh heap number, but don't overwrite r0 until
       // we're sure we can do it without going through the slow case
       // that needs the value in r0.
-      __ AllocateHeapNumber(r2, r3, r4, &slow);
+      __ AllocateHeapNumber(r2, r3, r4, r6, &slow);
       __ mov(r0, Operand(r2));
     }
 
     // WriteInt32ToHeapNumberStub does not trigger GC, so we do not
     // have to set up a frame.
     WriteInt32ToHeapNumberStub stub(r1, r0, r2);
     __ push(lr);
     __ Call(stub.GetCode(), RelocInfo::CODE_TARGET);
     __ pop(lr);
   } else {
@@ skipping 2209 matching lines @@
   __ bind(&string_add_runtime);
   __ TailCallRuntime(Runtime::kStringAdd, 2, 1);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM