Assembler changes for enabling GrowHeap in Wasm

src/arm/assembler-arm-inl.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // 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.
 //
@@ skipping 48 matching lines @@
   if (RelocInfo::IsInternalReference(rmode_)) {
     // absolute code pointer inside code object moves with the code object.
     int32_t* p = reinterpret_cast<int32_t*>(pc_);
     *p += delta;  // relocate entry
   }
   // We do not use pc relative addressing on ARM, so there is
   // nothing else to do.
 }
 
 
 Address RelocInfo::target_address() {

[titzer, 2016/03/03 18:11:59]

I think we should add new methods to deal specifically with wasm memory
references, as Yang had suggested elsewhere.

[gdeepti1, 2016/03/03 22:59:15]

Done.

-  DCHECK(IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_));
+  DCHECK(IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_) ||
+         IsWasmCodeEntry(rmode_));
   return Assembler::target_address_at(pc_, host_);
 }
 
 
 Address RelocInfo::target_address_address() {
   DCHECK(IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_)
                               || rmode_ == EMBEDDED_OBJECT
                               || rmode_ == EXTERNAL_REFERENCE);
   if (FLAG_enable_embedded_constant_pool ||
       Assembler::IsMovW(Memory::int32_at(pc_))) {
@@ skipping 12 matching lines @@
   DCHECK(IsInConstantPool());
   return Assembler::constant_pool_entry_address(pc_, host_->constant_pool());
 }
 
 
 int RelocInfo::target_address_size() {
   return kPointerSize;
 }
 
 
 void RelocInfo::set_target_address(Address target,

[titzer, 2016/03/03 18:11:59]

For the wasm memory reference version of this, I think we should have an
"update" style method, where the caller has to pass the old address and old
size. That's because we'll have memory references into the middle of the wasm
memory (i.e. with some non-zero offset from the start). We don't have to do that
case in this CL, but that will happen in a later one.

[gdeepti1, 2016/03/03 22:59:15]

Added a wasm memory reference version for now. I'll add the changes for updating
references in a follow up CL. 

                                    WriteBarrierMode write_barrier_mode,
                                    ICacheFlushMode icache_flush_mode) {
-  DCHECK(IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_));
+  DCHECK(IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_) ||
+         IsWasmCodeEntry(rmode_));
   Assembler::set_target_address_at(isolate_, pc_, host_, target,
                                    icache_flush_mode);
   if (write_barrier_mode == UPDATE_WRITE_BARRIER &&
       host() != NULL && IsCodeTarget(rmode_)) {
     Object* target_code = Code::GetCodeFromTargetAddress(target);
     host()->GetHeap()->incremental_marking()->RecordWriteIntoCode(
         host(), this, HeapObject::cast(target_code));
   }
 }
 
@@ skipping 486 matching lines @@
       Assembler::FlushICache(isolate, pc, 4 * kInstrSize);
     }
   }
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_ARM_ASSEMBLER_ARM_INL_H_