Add new relocation type WASM_MEMORY_SIZE_REFERENCE, use relocatable pointers to update wasm memory …

src/x64/assembler-x64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/x64/assembler-x64.h"
 
 #include <cstring>
 
 #if V8_TARGET_ARCH_X64
 
@@ skipping 96 matching lines @@
   printf(
       "SSE3=%d SSE4_1=%d SAHF=%d AVX=%d FMA3=%d BMI1=%d BMI2=%d LZCNT=%d "
       "POPCNT=%d ATOM=%d\n",
       CpuFeatures::IsSupported(SSE3), CpuFeatures::IsSupported(SSE4_1),
       CpuFeatures::IsSupported(SAHF), CpuFeatures::IsSupported(AVX),
       CpuFeatures::IsSupported(FMA3), CpuFeatures::IsSupported(BMI1),
       CpuFeatures::IsSupported(BMI2), CpuFeatures::IsSupported(LZCNT),
       CpuFeatures::IsSupported(POPCNT), CpuFeatures::IsSupported(ATOM));
 }
 
+// -----------------------------------------------------------------------------
+// Implementation of RelocInfo
+
+Address RelocInfo::wasm_memory_reference() {
+  DCHECK(IsWasmMemoryReference(rmode_));
+  return Memory::Address_at(pc_);
+}
+
+uint32_t RelocInfo::wasm_memory_size_reference() {
+  DCHECK(IsWasmMemorySizeReference(rmode_));
+  return Memory::uint32_at(pc_);
+}
+
+void RelocInfo::update_wasm_memory_reference(
+    Address old_base, Address new_base, uint32_t old_size, uint32_t new_size,
+    ICacheFlushMode icache_flush_mode) {
+  DCHECK(IsWasmMemoryReference(rmode_) || IsWasmMemorySizeReference(rmode_));
+  if (IsWasmMemoryReference(rmode_)) {
+    Address updated_reference;
+    DCHECK(old_base <= wasm_memory_reference() &&
+           wasm_memory_reference() < old_base + old_size);
+    updated_reference = new_base + (wasm_memory_reference() - old_base);
+    DCHECK(new_base <= updated_reference &&
+           updated_reference < new_base + new_size);
+    Memory::Address_at(pc_) = updated_reference;
+  } else if (IsWasmMemorySizeReference(rmode_)) {
+    uint32_t updated_size_reference;
+    DCHECK(wasm_memory_size_reference() <= old_size);
+    updated_size_reference =
+        new_size + (wasm_memory_size_reference() - old_size);
+    DCHECK(updated_size_reference <= new_size);
+    Memory::uint32_at(pc_) = updated_size_reference;
+  } else {
+    UNREACHABLE();
+  }
+  if (icache_flush_mode != SKIP_ICACHE_FLUSH) {
+    Assembler::FlushICache(isolate_, pc_, sizeof(int64_t));
+  }
+}
 
 // -----------------------------------------------------------------------------
 // Implementation of Operand
 
 Operand::Operand(Register base, int32_t disp) : rex_(0) {
   len_ = 1;
   if (base.is(rsp) || base.is(r12)) {
     // SIB byte is needed to encode (rsp + offset) or (r12 + offset).
     set_sib(times_1, rsp, base);
   }
@@ skipping 429 matching lines @@
 
 void Assembler::immediate_arithmetic_op(byte subcode,
                                         Register dst,
                                         Immediate src,
                                         int size) {
   EnsureSpace ensure_space(this);
   emit_rex(dst, size);
   if (is_int8(src.value_)) {
     emit(0x83);
     emit_modrm(subcode, dst);
+    if (!RelocInfo::IsNone(src.rmode_)) {
+      RecordRelocInfo(src.rmode_);
+    }
     emit(src.value_);
   } else if (dst.is(rax)) {
     emit(0x05 | (subcode << 3));
-    emitl(src.value_);
+    emit(src);
   } else {
     emit(0x81);
     emit_modrm(subcode, dst);
-    emitl(src.value_);
+    emit(src);
   }
 }
 
 void Assembler::immediate_arithmetic_op(byte subcode,
                                         const Operand& dst,
                                         Immediate src,
                                         int size) {
   EnsureSpace ensure_space(this);
   emit_rex(dst, size);
   if (is_int8(src.value_)) {
     emit(0x83);
     emit_operand(subcode, dst);
+    if (!RelocInfo::IsNone(src.rmode_)) {
+      RecordRelocInfo(src.rmode_);
+    }
     emit(src.value_);
   } else {
     emit(0x81);
     emit_operand(subcode, dst);
-    emitl(src.value_);
+    emit(src);
   }
 }
 
 
 void Assembler::immediate_arithmetic_op_16(byte subcode,
                                            Register dst,
                                            Immediate src) {
   EnsureSpace ensure_space(this);
   emit(0x66);  // Operand size override prefix.
   emit_optional_rex_32(dst);
@@ skipping 3612 matching lines @@
 
 bool RelocInfo::IsInConstantPool() {
   return false;
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64