[assembler] Introduce RelocInfo::NEAR_BUILTIN_ENTRY

... for PC-relative builtin calls/jumps and explicitly use near_call /
near_jump instructions.

This is a step towards
1) removing the RelocInfo::RUNTIME_ENTRY which was temporarily used
   for this purpose,
2) being able to remap embedded builtins into the code range multiple
   times.

Bug: v8:11527
Change-Id: Ife26c8bbc524be0b07f333776716f22bd4bd36aa
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3866190
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Jakob Linke <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/main@{#82884}

src/codegen/arm/assembler-arm-inl.h

@@ -151,6 +151,8 @@ Address RelocInfo::target_internal_reference_address() {
   return pc_;
 }
 
+Builtin RelocInfo::target_builtin_at(Assembler* origin) { UNREACHABLE(); }
+
 Address RelocInfo::target_runtime_entry(Assembler* origin) {
   DCHECK(IsRuntimeEntry(rmode_));
   return target_address();

src/codegen/arm64/assembler-arm64-inl.h

@@ -528,6 +528,15 @@ Handle<HeapObject> Assembler::target_object_handle_at(Address pc) {
       Assembler::embedded_object_index_referenced_from(pc));
 }
 
+Builtin Assembler::target_builtin_at(Address pc) {
+  Instruction* instr = reinterpret_cast<Instruction*>(pc);
+  DCHECK(instr->IsBranchAndLink() || instr->IsUnconditionalBranch());
+  DCHECK_EQ(instr->ImmPCOffset() % kInstrSize, 0);
+  int builtin_id = static_cast<int>(instr->ImmPCOffset() / kInstrSize);
+  DCHECK(Builtins::IsBuiltinId(builtin_id));
+  return static_cast<Builtin>(builtin_id);
+}
+
 Address Assembler::runtime_entry_at(Address pc) {
   Instruction* instr = reinterpret_cast<Instruction*>(pc);
   if (instr->IsLdrLiteralX()) {
@@ -620,7 +629,8 @@ int RelocInfo::target_address_size() {
 }
 
 Address RelocInfo::target_address() {
-  DCHECK(IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_) || IsWasmCall(rmode_));
+  DCHECK(IsCodeTarget(rmode_) || IsNearBuiltinEntry(rmode_) ||
+         IsRuntimeEntry(rmode_) || IsWasmCall(rmode_));
   return Assembler::target_address_at(pc_, constant_pool_);
 }
 
@@ -726,9 +736,14 @@ Address RelocInfo::target_internal_reference_address() {
   return pc_;
 }
 
+Builtin RelocInfo::target_builtin_at(Assembler* origin) {
+  DCHECK(IsNearBuiltinEntry(rmode_));
+  return Assembler::target_builtin_at(pc_);
+}
+
 Address RelocInfo::target_runtime_entry(Assembler* origin) {
   DCHECK(IsRuntimeEntry(rmode_));
-  return origin->runtime_entry_at(pc_);
+  return target_address();
 }
 
 void RelocInfo::set_target_runtime_entry(Address target,

src/codegen/arm64/assembler-arm64.cc

@@ -187,6 +187,7 @@ CPURegList CPURegList::GetCallerSavedV(int size) {
 
 const int RelocInfo::kApplyMask =
     RelocInfo::ModeMask(RelocInfo::CODE_TARGET) |
+    RelocInfo::ModeMask(RelocInfo::NEAR_BUILTIN_ENTRY) |
     RelocInfo::ModeMask(RelocInfo::RUNTIME_ENTRY) |
     RelocInfo::ModeMask(RelocInfo::INTERNAL_REFERENCE);
 

src/codegen/arm64/assembler-arm64.h

@@ -269,6 +269,11 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   // Returns the handle for the heap object referenced at 'pc'.
   inline Handle<HeapObject> target_object_handle_at(Address pc);
 
+  // During code generation builtin targets in PC-relative call/jump
+  // instructions are temporarily encoded as builtin ID until the generated
+  // code is moved into the code space.
+  static inline Builtin target_builtin_at(Address pc);
+
   // Returns the target address for a runtime function for the call encoded
   // at 'pc'.
   // Runtime entries can be temporarily encoded as the offset between the

src/codegen/arm64/macro-assembler-arm64.cc

@@ -2033,8 +2033,6 @@ void TurboAssembler::JumpHelper(int64_t offset, RelocInfo::Mode rmode,
 
 // The calculated offset is either:
 // * the 'target' input unmodified if this is a Wasm call, or
-// * the offset of the target from the code range start, if this is a call to
-//   un-embedded builtin, or
 // * the offset of the target from the current PC, in instructions, for any
 //   other type of call.
 int64_t TurboAssembler::CalculateTargetOffset(Address target,
@@ -2045,18 +2043,7 @@ int64_t TurboAssembler::CalculateTargetOffset(Address target,
     // address at this point, and needs to be encoded as-is.
     return offset;
   }
-  if (RelocInfo::IsRuntimeEntry(rmode)) {
-    // The runtime entry targets are used for generating short builtin calls
-    // from JIT-compiled code (it's not used during snapshot creation).
-    // The value is encoded as an offset from the code range (see
-    // Assembler::runtime_entry_at()).
-    // Note, that builtin-to-builitin calls use different OFF_HEAP_TARGET mode
-    // and therefore are encoded differently.
-    DCHECK_NE(options().code_range_base, 0);
-    offset -= static_cast<int64_t>(options().code_range_base);
-  } else {
-    offset -= reinterpret_cast<int64_t>(pc);
-  }
+  offset -= reinterpret_cast<int64_t>(pc);
   DCHECK_EQ(offset % kInstrSize, 0);
   offset = offset / static_cast<int>(kInstrSize);
   return offset;
@@ -2194,7 +2181,7 @@ void TurboAssembler::CallBuiltin(Builtin builtin) {
       break;
     }
     case BuiltinCallJumpMode::kPCRelative:
-      Call(BuiltinEntry(builtin), RelocInfo::RUNTIME_ENTRY);
+      near_call(static_cast<int>(builtin), RelocInfo::NEAR_BUILTIN_ENTRY);
       break;
     case BuiltinCallJumpMode::kIndirect: {
       UseScratchRegisterScope temps(this);
@@ -2220,6 +2207,7 @@ void TurboAssembler::CallBuiltin(Builtin builtin) {
   }
 }
 
+// TODO(ishell): remove cond parameter from here to simplify things.
 void TurboAssembler::TailCallBuiltin(Builtin builtin, Condition cond) {
   ASM_CODE_COMMENT_STRING(this,
                           CommentForOffHeapTrampoline("tail call", builtin));
@@ -2241,9 +2229,15 @@ void TurboAssembler::TailCallBuiltin(Builtin builtin, Condition cond) {
       Jump(temp, cond);
       break;
     }
-    case BuiltinCallJumpMode::kPCRelative:
-      Jump(BuiltinEntry(builtin), RelocInfo::RUNTIME_ENTRY, cond);
+    case BuiltinCallJumpMode::kPCRelative: {
+      if (cond != nv) {
+        Label done;
+        if (cond != al) B(NegateCondition(cond), &done);
+        near_jump(static_cast<int>(builtin), RelocInfo::NEAR_BUILTIN_ENTRY);
+        Bind(&done);
+      }
       break;
+    }
     case BuiltinCallJumpMode::kIndirect: {
       LoadEntryFromBuiltin(builtin, temp);
       Jump(temp, cond);

src/codegen/assembler.cc

@@ -77,7 +77,7 @@ AssemblerOptions AssemblerOptions::Default(Isolate* isolate) {
       isolate->is_short_builtin_calls_enabled() &&
       !generating_embedded_builtin &&
       (options.code_range_base != kNullAddress) &&
-      // Serialization of RUNTIME_ENTRY reloc infos is not supported yet.
+      // Serialization of NEAR_BUILTIN_ENTRY reloc infos is not supported yet.
       !serializer;
   if (short_builtin_calls) {
     options.builtin_call_jump_mode = BuiltinCallJumpMode::kPCRelative;

src/codegen/ia32/assembler-ia32-inl.h

@@ -130,6 +130,8 @@ Address RelocInfo::target_internal_reference_address() {
   return pc_;
 }
 
+Builtin RelocInfo::target_builtin_at(Assembler* origin) { UNREACHABLE(); }
+
 Address RelocInfo::target_runtime_entry(Assembler* origin) {
   DCHECK(IsRuntimeEntry(rmode_));
   return ReadUnalignedValue<Address>(pc_);

src/codegen/loong64/assembler-loong64-inl.h

@@ -159,6 +159,8 @@ Handle<Code> Assembler::relative_code_target_object_handle_at(
   return GetCodeTarget(code_target_index);
 }
 
+Builtin RelocInfo::target_builtin_at(Assembler* origin) { UNREACHABLE(); }
+
 Address RelocInfo::target_runtime_entry(Assembler* origin) {
   DCHECK(IsRuntimeEntry(rmode_));
   return target_address();

src/codegen/mips/assembler-mips-inl.h

@@ -231,6 +231,8 @@ Address RelocInfo::target_internal_reference_address() {
   return pc_;
 }
 
+Builtin RelocInfo::target_builtin_at(Assembler* origin) { UNREACHABLE(); }
+
 Address RelocInfo::target_runtime_entry(Assembler* origin) {
   DCHECK(IsRuntimeEntry(rmode_));
   return target_address();

src/codegen/mips64/assembler-mips64-inl.h

@@ -203,6 +203,8 @@ Address RelocInfo::target_internal_reference_address() {
   return pc_;
 }
 
+Builtin RelocInfo::target_builtin_at(Assembler* origin) { UNREACHABLE(); }
+
 Address RelocInfo::target_runtime_entry(Assembler* origin) {
   DCHECK(IsRuntimeEntry(rmode_));
   return target_address();

src/codegen/ppc/assembler-ppc-inl.h

@@ -212,6 +212,8 @@ void RelocInfo::set_target_external_reference(
                                    icache_flush_mode);
 }
 
+Builtin RelocInfo::target_builtin_at(Assembler* origin) { UNREACHABLE(); }
+
 Address RelocInfo::target_runtime_entry(Assembler* origin) {
   DCHECK(IsRuntimeEntry(rmode_));
   return target_address();

src/codegen/reloc-info.cc

@@ -345,8 +345,8 @@ void RelocInfo::set_wasm_stub_call_address(Address address,
 void RelocInfo::set_target_address(Address target,
                                    WriteBarrierMode write_barrier_mode,
                                    ICacheFlushMode icache_flush_mode) {
-  DCHECK(IsCodeTargetMode(rmode_) || IsRuntimeEntry(rmode_) ||
-         IsWasmCall(rmode_));
+  DCHECK(IsCodeTargetMode(rmode_) || IsNearBuiltinEntry(rmode_) ||
+         IsRuntimeEntry(rmode_) || IsWasmCall(rmode_));
   Assembler::set_target_address_at(pc_, constant_pool_, target,
                                    icache_flush_mode);
   if (!host().is_null() && IsCodeTargetMode(rmode_) &&
@@ -416,6 +416,8 @@ const char* RelocInfo::RelocModeName(RelocInfo::Mode rmode) {
       return "encoded internal reference";
     case OFF_HEAP_TARGET:
       return "off heap target";
+    case NEAR_BUILTIN_ENTRY:
+      return "near builtin entry";
     case DEOPT_SCRIPT_OFFSET:
       return "deopt script offset";
     case DEOPT_INLINING_ID:
@@ -527,6 +529,13 @@ void RelocInfo::Verify(Isolate* isolate) {
           OffHeapInstructionStream::TryLookupCode(isolate, addr)));
       break;
     }
+    case NEAR_BUILTIN_ENTRY: {
+      Address addr = target_address();
+      CHECK_NE(addr, kNullAddress);
+      CHECK(Builtins::IsBuiltinId(
+          OffHeapInstructionStream::TryLookupCode(isolate, addr)));
+      break;
+    }
     case RUNTIME_ENTRY:
     case EXTERNAL_REFERENCE:
     case DEOPT_SCRIPT_OFFSET:

src/codegen/reloc-info.h

@@ -56,6 +56,7 @@ class RelocInfo {
     NO_INFO,  // Never recorded value. Most common one, hence value 0.
 
     CODE_TARGET,
+    // TODO(ishell): rename to NEAR_CODE_TARGET.
     RELATIVE_CODE_TARGET,  // LAST_CODE_TARGET_MODE
     COMPRESSED_EMBEDDED_OBJECT,
     FULL_EMBEDDED_OBJECT,
@@ -64,9 +65,7 @@ class RelocInfo {
     WASM_CALL,  // FIRST_SHAREABLE_RELOC_MODE
     WASM_STUB_CALL,
 
-    // TODO(ishell): rename to UNEMBEDDED_BUILTIN_ENTRY.
-    // An un-embedded off-heap instruction stream target.
-    // See http://crbug.com/v8/11527 for details.
+    // TODO(ishell): This reloc info shouldn't be used anymore. Remove it.
     RUNTIME_ENTRY,
 
     EXTERNAL_REFERENCE,  // The address of an external C++ function.
@@ -77,7 +76,11 @@ class RelocInfo {
     INTERNAL_REFERENCE_ENCODED,
 
     // An off-heap instruction stream target. See http://goo.gl/Z2HUiM.
-    OFF_HEAP_TARGET,
+    // TODO(ishell): rename to BUILTIN_ENTRY.
+    OFF_HEAP_TARGET,  // FIRST_BUILTIN_ENTRY_MODE
+    // An un-embedded off-heap instruction stream target.
+    // See http://crbug.com/v8/11527 for details.
+    NEAR_BUILTIN_ENTRY,  // LAST_BUILTIN_ENTRY_MODE
 
     // Marks constant and veneer pools. Only used on ARM and ARM64.
     // They use a custom noncompact encoding.
@@ -106,6 +109,8 @@ class RelocInfo {
     FIRST_EMBEDDED_OBJECT_RELOC_MODE = COMPRESSED_EMBEDDED_OBJECT,
     LAST_EMBEDDED_OBJECT_RELOC_MODE = DATA_EMBEDDED_OBJECT,
     LAST_GCED_ENUM = LAST_EMBEDDED_OBJECT_RELOC_MODE,
+    FIRST_BUILTIN_ENTRY_MODE = OFF_HEAP_TARGET,
+    LAST_BUILTIN_ENTRY_MODE = NEAR_BUILTIN_ENTRY,
     FIRST_SHAREABLE_RELOC_MODE = WASM_CALL,
   };
 
@@ -155,7 +160,6 @@ class RelocInfo {
     return base::IsInRange(mode, FIRST_EMBEDDED_OBJECT_RELOC_MODE,
                            LAST_EMBEDDED_OBJECT_RELOC_MODE);
   }
-  // TODO(ishell): rename to IsUnembeddedBuiltinEntry().
   static constexpr bool IsRuntimeEntry(Mode mode) {
     return mode == RUNTIME_ENTRY;
   }
@@ -191,6 +195,13 @@ class RelocInfo {
   static constexpr bool IsOffHeapTarget(Mode mode) {
     return mode == OFF_HEAP_TARGET;
   }
+  static constexpr bool IsNearBuiltinEntry(Mode mode) {
+    return mode == NEAR_BUILTIN_ENTRY;
+  }
+  static constexpr bool IsBuiltinEntryMode(Mode mode) {
+    return base::IsInRange(mode, FIRST_BUILTIN_ENTRY_MODE,
+                           LAST_BUILTIN_ENTRY_MODE);
+  }
   static constexpr bool IsNoInfo(Mode mode) { return mode == NO_INFO; }
 
   static bool IsOnlyForSerializer(Mode mode) {
@@ -265,6 +276,9 @@ class RelocInfo {
       Heap* heap, HeapObject target,
       WriteBarrierMode write_barrier_mode = UPDATE_WRITE_BARRIER,
       ICacheFlushMode icache_flush_mode = FLUSH_ICACHE_IF_NEEDED);
+  // Decodes builtin ID encoded as a PC-relative offset. This encoding is used
+  // during code generation of call/jump with NEAR_BUILTIN_ENTRY.
+  V8_INLINE Builtin target_builtin_at(Assembler* origin);
   V8_INLINE Address target_runtime_entry(Assembler* origin);
   V8_INLINE void set_target_runtime_entry(
       Address target,
@@ -327,7 +341,7 @@ class RelocInfo {
       visitor->VisitInternalReference(host(), this);
     } else if (IsRuntimeEntry(mode)) {
       visitor->VisitRuntimeEntry(host(), this);
-    } else if (IsOffHeapTarget(mode)) {
+    } else if (IsBuiltinEntryMode(mode)) {
       visitor->VisitOffHeapTarget(host(), this);
     }
   }
@@ -369,6 +383,7 @@ class RelocInfo {
            ModeMask(RelocInfo::COMPRESSED_EMBEDDED_OBJECT) |
            ModeMask(RelocInfo::FULL_EMBEDDED_OBJECT) |
            ModeMask(RelocInfo::DATA_EMBEDDED_OBJECT) |
+           ModeMask(RelocInfo::NEAR_BUILTIN_ENTRY) |
            ModeMask(RelocInfo::RUNTIME_ENTRY) |
            ModeMask(RelocInfo::RELATIVE_CODE_TARGET) | kApplyMask;
   }

src/codegen/riscv/assembler-riscv-inl.h

@@ -250,6 +250,8 @@ Handle<Code> Assembler::relative_code_target_object_handle_at(
   return Handle<Code>::cast(GetEmbeddedObject(code_target_index));
 }
 
+Builtin RelocInfo::target_builtin_at(Assembler* origin) { UNREACHABLE(); }
+
 Address RelocInfo::target_runtime_entry(Assembler* origin) {
   DCHECK(IsRuntimeEntry(rmode_));
   return target_address();

src/codegen/s390/assembler-s390-inl.h

@@ -206,6 +206,8 @@ void RelocInfo::set_target_external_reference(
                                    icache_flush_mode);
 }
 
+Builtin RelocInfo::target_builtin_at(Assembler* origin) { UNREACHABLE(); }
+
 Address RelocInfo::target_runtime_entry(Assembler* origin) {
   DCHECK(IsRuntimeEntry(rmode_));
   return target_address();

src/codegen/turbo-assembler.cc

@@ -29,8 +29,7 @@ TurboAssemblerBase::TurboAssemblerBase(Isolate* isolate,
 Address TurboAssemblerBase::BuiltinEntry(Builtin builtin) {
   DCHECK(Builtins::IsBuiltinId(builtin));
   if (isolate_ != nullptr) {
-    Address entry =
-        isolate_->builtin_entry_table()[static_cast<int32_t>(builtin)];
+    Address entry = isolate_->builtin_entry_table()[Builtins::ToInt(builtin)];
     DCHECK_EQ(entry, EmbeddedData::FromBlob(isolate_).InstructionStartOfBuiltin(
                          builtin));
     return entry;

src/codegen/x64/assembler-x64-inl.h

@@ -35,7 +35,6 @@ void Assembler::emitw(uint16_t x) {
   pc_ += sizeof(uint16_t);
 }
 
-// TODO(ishell): Rename accordingly once RUNTIME_ENTRY is renamed.
 void Assembler::emit_runtime_entry(Address entry, RelocInfo::Mode rmode) {
   DCHECK(RelocInfo::IsRuntimeEntry(rmode));
   DCHECK_NE(options().code_range_base, 0);
@@ -272,6 +271,12 @@ Handle<HeapObject> Assembler::compressed_embedded_object_handle_at(Address pc) {
   return GetEmbeddedObject(ReadUnalignedValue<uint32_t>(pc));
 }
 
+Builtin Assembler::target_builtin_at(Address pc) {
+  int32_t builtin_id = ReadUnalignedValue<int32_t>(pc);
+  DCHECK(Builtins::IsBuiltinId(builtin_id));
+  return static_cast<Builtin>(builtin_id);
+}
+
 Address Assembler::runtime_entry_at(Address pc) {
   return ReadUnalignedValue<int32_t>(pc) + options().code_range_base;
 }
@@ -281,7 +286,8 @@ Address Assembler::runtime_entry_at(Address pc) {
 
 // The modes possibly affected by apply must be in kApplyMask.
 void RelocInfo::apply(intptr_t delta) {
-  if (IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_)) {
+  if (IsCodeTarget(rmode_) || IsNearBuiltinEntry(rmode_) ||
+      IsRuntimeEntry(rmode_)) {
     WriteUnalignedValue(
         pc_, ReadUnalignedValue<int32_t>(pc_) - static_cast<int32_t>(delta));
   } else if (IsInternalReference(rmode_)) {
@@ -291,7 +297,8 @@ void RelocInfo::apply(intptr_t delta) {
 }
 
 Address RelocInfo::target_address() {
-  DCHECK(IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_) || IsWasmCall(rmode_));
+  DCHECK(IsCodeTarget(rmode_) || IsNearBuiltinEntry(rmode_) ||
+         IsRuntimeEntry(rmode_) || IsWasmCall(rmode_));
   return Assembler::target_address_at(pc_, constant_pool_);
 }
 
@@ -387,9 +394,14 @@ void RelocInfo::set_target_object(Heap* heap, HeapObject target,
   }
 }
 
+Builtin RelocInfo::target_builtin_at(Assembler* origin) {
+  DCHECK(IsNearBuiltinEntry(rmode_));
+  return Assembler::target_builtin_at(pc_);
+}
+
 Address RelocInfo::target_runtime_entry(Assembler* origin) {
   DCHECK(IsRuntimeEntry(rmode_));
-  return origin->runtime_entry_at(pc_);
+  return target_address();
 }
 
 void RelocInfo::set_target_runtime_entry(Address target,
@@ -413,7 +425,8 @@ void RelocInfo::WipeOut() {
   } else if (IsCompressedEmbeddedObject(rmode_)) {
     Address smi_address = Smi::FromInt(0).ptr();
     WriteUnalignedValue(pc_, CompressTagged(smi_address));
-  } else if (IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_)) {
+  } else if (IsCodeTarget(rmode_) || IsNearBuiltinEntry(rmode_) ||
+             IsRuntimeEntry(rmode_)) {
     // Effectively write zero into the relocation.
     Assembler::set_target_address_at(pc_, constant_pool_,
                                      pc_ + sizeof(int32_t));

src/codegen/x64/assembler-x64.cc

@@ -1011,6 +1011,7 @@ void Assembler::call(Handle<CodeT> target, RelocInfo::Mode rmode) {
 
 void Assembler::near_call(intptr_t disp, RelocInfo::Mode rmode) {
   EnsureSpace ensure_space(this);
+  // 1110 1000 #32-bit disp.
   emit(0xE8);
   DCHECK(is_int32(disp));
   RecordRelocInfo(rmode);
@@ -1019,6 +1020,7 @@ void Assembler::near_call(intptr_t disp, RelocInfo::Mode rmode) {
 
 void Assembler::near_jmp(intptr_t disp, RelocInfo::Mode rmode) {
   EnsureSpace ensure_space(this);
+  // 1110 1001 #32-bit disp.
   emit(0xE9);
   DCHECK(is_int32(disp));
   if (!RelocInfo::IsNoInfo(rmode)) RecordRelocInfo(rmode);
@@ -4462,6 +4464,7 @@ void Assembler::RecordRelocInfo(RelocInfo::Mode rmode, intptr_t data) {
 
 const int RelocInfo::kApplyMask =
     RelocInfo::ModeMask(RelocInfo::CODE_TARGET) |
+    RelocInfo::ModeMask(RelocInfo::NEAR_BUILTIN_ENTRY) |
     RelocInfo::ModeMask(RelocInfo::RUNTIME_ENTRY) |
     RelocInfo::ModeMask(RelocInfo::INTERNAL_REFERENCE) |
     RelocInfo::ModeMask(RelocInfo::WASM_CALL);

src/codegen/x64/assembler-x64.h

@@ -455,6 +455,11 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
       ICacheFlushMode icache_flush_mode = FLUSH_ICACHE_IF_NEEDED);
   static inline int32_t relative_target_offset(Address target, Address pc);
 
+  // During code generation builtin targets in PC-relative call/jump
+  // instructions are temporarily encoded as builtin ID until the generated
+  // code is moved into the code space.
+  static inline Builtin target_builtin_at(Address pc);
+
   // This sets the branch destination (which is in the instruction on x64).
   // This is for calls and branches within generated code.
   inline static void deserialization_set_special_target_at(

src/codegen/x64/macro-assembler-x64.cc

@@ -2179,7 +2179,7 @@ void TurboAssembler::CallBuiltin(Builtin builtin) {
       Call(BuiltinEntry(builtin), RelocInfo::OFF_HEAP_TARGET);
       break;
     case BuiltinCallJumpMode::kPCRelative:
-      call(BuiltinEntry(builtin), RelocInfo::RUNTIME_ENTRY);
+      near_call(static_cast<intptr_t>(builtin), RelocInfo::NEAR_BUILTIN_ENTRY);
       break;
     case BuiltinCallJumpMode::kIndirect:
       Call(EntryFromBuiltinAsOperand(builtin));
@@ -2200,7 +2200,7 @@ void TurboAssembler::TailCallBuiltin(Builtin builtin) {
       Jump(BuiltinEntry(builtin), RelocInfo::OFF_HEAP_TARGET);
       break;
     case BuiltinCallJumpMode::kPCRelative:
-      jmp(BuiltinEntry(builtin), RelocInfo::RUNTIME_ENTRY);
+      near_jmp(static_cast<intptr_t>(builtin), RelocInfo::NEAR_BUILTIN_ENTRY);
       break;
     case BuiltinCallJumpMode::kIndirect:
       Jump(EntryFromBuiltinAsOperand(builtin));

src/objects/code.cc

@@ -207,6 +207,14 @@ void Code::RelocateFromDesc(ByteArray reloc_info, Heap* heap,
       Code code = FromCodeT(CodeT::cast(*p));
       it.rinfo()->set_target_address(code.raw_instruction_start(),
                                      UPDATE_WRITE_BARRIER, SKIP_ICACHE_FLUSH);
+    } else if (RelocInfo::IsNearBuiltinEntry(mode)) {
+      // Rewrite builtin IDs to PC-relative offset to the builtin entry point.
+      Builtin builtin = it.rinfo()->target_builtin_at(origin);
+      Address p =
+          heap->isolate()->builtin_entry_table()[Builtins::ToInt(builtin)];
+      it.rinfo()->set_target_address(p, UPDATE_WRITE_BARRIER,
+                                     SKIP_ICACHE_FLUSH);
+      DCHECK_EQ(p, it.rinfo()->target_address());
     } else if (RelocInfo::IsRuntimeEntry(mode)) {
       Address p = it.rinfo()->target_runtime_entry(origin);
       it.rinfo()->set_target_runtime_entry(p, UPDATE_WRITE_BARRIER,
@@ -365,6 +373,7 @@ bool Code::IsIsolateIndependent(Isolate* isolate) {
                  RelocInfo::ModeMask(RelocInfo::EXTERNAL_REFERENCE) |
                  RelocInfo::ModeMask(RelocInfo::INTERNAL_REFERENCE) |
                  RelocInfo::ModeMask(RelocInfo::INTERNAL_REFERENCE_ENCODED) |
+                 RelocInfo::ModeMask(RelocInfo::NEAR_BUILTIN_ENTRY) |
                  RelocInfo::ModeMask(RelocInfo::RUNTIME_ENTRY) |
                  RelocInfo::ModeMask(RelocInfo::WASM_CALL) |
                  RelocInfo::ModeMask(RelocInfo::WASM_STUB_CALL)));

src/objects/visitors.h

@@ -174,7 +174,8 @@ class ObjectVisitor {
   // Visits an (encoded) internal reference.
   virtual void VisitInternalReference(Code host, RelocInfo* rinfo) {}
 
-  // Visits an off-heap target in the instruction stream.
+  // Visits an off-heap target or near builtin entry in the instruction stream.
+  // TODO(ishell): rename to VisitBuiltinEntry.
   virtual void VisitOffHeapTarget(Code host, RelocInfo* rinfo) {}
 
   // Visits the relocation info using the given iterator.

src/snapshot/deserializer.cc

@@ -801,6 +801,9 @@ void DeserializerRelocInfoVisitor::VisitInternalReference(Code host,
 
 void DeserializerRelocInfoVisitor::VisitOffHeapTarget(Code host,
                                                       RelocInfo* rinfo) {
+  // Currently we don't serialize code that contains near builtin entries.
+  DCHECK_NE(rinfo->rmode(), RelocInfo::NEAR_BUILTIN_ENTRY);
+
   byte data = source().Get();
   CHECK_EQ(data, Deserializer<Isolate>::kOffHeapTarget);
 

src/snapshot/serializer.cc

@@ -1134,6 +1134,9 @@ void Serializer::ObjectSerializer::VisitOffHeapTarget(Code host,
                                                       RelocInfo* rinfo) {
   static_assert(EmbeddedData::kTableSize == Builtins::kBuiltinCount);
 
+  // Currently we don't serialize code that contains near builtin entries.
+  CHECK_NE(rinfo->rmode(), RelocInfo::NEAR_BUILTIN_ENTRY);
+
   Address addr = rinfo->target_off_heap_target();
   CHECK_NE(kNullAddress, addr);