Revert "[wasm][liftoff] Support for most externref globals"

This reverts commit e43ec59b.

Reason for revert: https://logs.chromium.org/logs/v8/buildbucket/cr-buildbucket.appspot.com/8869719317069732832/+/steps/Check_-_d8/0/logs/externref-globals-liftoff/0

Original change's description:
> [wasm][liftoff] Support for most externref globals
> 
> With this CL we add support for all externref globals except for
> imported mutable globals.
> 
> R=​thibaudm@chromium.org
> 
> Bug: v8:7581
> Change-Id: I63cb26f8ad6f4b8fc1c276e223c5d45745122ebf
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2396086
> Commit-Queue: Andreas Haas <ahaas@chromium.org>
> Reviewed-by: Thibaud Michaud <thibaudm@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#69741}

TBR=ahaas@chromium.org,thibaudm@chromium.org

Change-Id: I19d191862aa91a116ea84a4a59a3a0a8036fcb49
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:7581
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2398643
Commit-Queue: Sathya Gunasekaran  <gsathya@chromium.org>
Reviewed-by: Sathya Gunasekaran  <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69744}

src/wasm/baseline/arm/liftoff-assembler-arm.h

@@ -659,15 +659,6 @@ void LiftoffAssembler::LoadTaggedPointer(Register dst, Register src_addr,
                         offset_imm, LoadType::kI32Load, pinned);
 }
 
-void LiftoffAssembler::StoreTaggedPointer(Register dst_addr,
-                                          Register offset_reg,
-                                          int32_t offset_imm,
-                                          LiftoffRegister src,
-                                          LiftoffRegList pinned) {
-  STATIC_ASSERT(kTaggedSize == kInt32Size);
-  Store(dst_addr, offset_reg, offset_imm, src, StoreType::kI32Store, pinned);
-}
-
 void LiftoffAssembler::Load(LiftoffRegister dst, Register src_addr,
                             Register offset_reg, uint32_t offset_imm,
                             LoadType type, LiftoffRegList pinned,

src/wasm/baseline/arm64/liftoff-assembler-arm64.h

@@ -338,17 +338,6 @@ void LiftoffAssembler::LoadTaggedPointer(Register dst, Register src_addr,
   LoadTaggedPointerField(dst, src_op);
 }
 
-void LiftoffAssembler::StoreTaggedPointer(Register dst_addr,
-                                          Register offset_reg,
-                                          int32_t offset_imm,
-                                          LiftoffRegister src,
-                                          LiftoffRegList pinned) {
-  UseScratchRegisterScope temps(this);
-  MemOperand dst_op =
-      liftoff::GetMemOp(this, &temps, dst_addr, offset_reg, offset_imm);
-  StoreTaggedField(src.gp(), dst_op);
-}
-
 void LiftoffAssembler::Load(LiftoffRegister dst, Register src_addr,
                             Register offset_reg, uint32_t offset_imm,
                             LoadType type, LiftoffRegList pinned,

src/wasm/baseline/ia32/liftoff-assembler-ia32.h

@@ -291,16 +291,6 @@ void LiftoffAssembler::LoadTaggedPointer(Register dst, Register src_addr,
        static_cast<uint32_t>(offset_imm), LoadType::kI32Load, pinned);
 }
 
-void LiftoffAssembler::StoreTaggedPointer(Register dst_addr,
-                                          Register offset_reg,
-                                          int32_t offset_imm,
-                                          LiftoffRegister src,
-                                          LiftoffRegList pinned) {
-  DCHECK_GE(offset_imm, 0);
-  STATIC_ASSERT(kTaggedSize == kInt32Size);
-  Store(dst_addr, offset_reg, offset_imm, src, StoreType::kI32Store, pinned);
-}
-
 void LiftoffAssembler::Load(LiftoffRegister dst, Register src_addr,
                             Register offset_reg, uint32_t offset_imm,
                             LoadType type, LiftoffRegList pinned,

src/wasm/baseline/liftoff-assembler.h

@@ -485,9 +485,6 @@ class LiftoffAssembler : public TurboAssembler {
   inline void LoadTaggedPointer(Register dst, Register src_addr,
                                 Register offset_reg, int32_t offset_imm,
                                 LiftoffRegList pinned);
-  inline void StoreTaggedPointer(Register dst_addr, Register offset_reg,
-                                 int32_t offset_imm, LiftoffRegister src,
-                                 LiftoffRegList pinned);
   inline void Load(LiftoffRegister dst, Register src_addr, Register offset_reg,
                    uint32_t offset_imm, LoadType type, LiftoffRegList pinned,
                    uint32_t* protected_load_pc = nullptr,

src/wasm/baseline/liftoff-compiler.cc

@@ -1813,30 +1813,8 @@ class LiftoffCompiler {
   void GlobalGet(FullDecoder* decoder, Value* result,
                  const GlobalIndexImmediate<validate>& imm) {
     const auto* global = &env_->module->globals[imm.index];
-    if (!CheckSupportedType(decoder,
-                            FLAG_liftoff_extern_ref
-                                ? kSupportedTypes
-                                : kSupportedTypesWithoutRefs,
-                            global->type, "global")) {
-      return;
-    }
-
-    if (global->type.is_reference_type()) {
-      if (global->mutability && global->imported) {
-        unsupported(decoder, kRefTypes, "imported mutable globals");
-        return;
-      }
-
-      LiftoffRegList pinned;
-      Register globals_buffer =
-          pinned.set(__ GetUnusedRegister(kGpReg, pinned)).gp();
-      LOAD_TAGGED_PTR_INSTANCE_FIELD(globals_buffer, TaggedGlobalsBuffer);
-      Register value = pinned.set(__ GetUnusedRegister(kGpReg, pinned)).gp();
-      __ LoadTaggedPointer(value, globals_buffer, no_reg,
-                           wasm::ObjectAccess::ElementOffsetInTaggedFixedArray(
-                               imm.global->offset),
-                           pinned);
-      __ PushRegister(global->type, LiftoffRegister(value));
+    if (!CheckSupportedType(decoder, kSupportedTypesWithoutRefs, global->type,
+                            "global")) {
       return;
     }
     LiftoffRegList pinned;
@@ -1852,31 +1830,9 @@ class LiftoffCompiler {
   void GlobalSet(FullDecoder* decoder, const Value& value,
                  const GlobalIndexImmediate<validate>& imm) {
     auto* global = &env_->module->globals[imm.index];
-    if (!CheckSupportedType(decoder,
-                            FLAG_liftoff_extern_ref
-                                ? kSupportedTypes
-                                : kSupportedTypesWithoutRefs,
-                            global->type, "global")) {
+    if (!CheckSupportedType(decoder, kSupportedTypesWithoutRefs, global->type,
+                            "global"))
       return;
-    }
-
-    if (global->type.is_reference_type()) {
-      if (global->mutability && global->imported) {
-        unsupported(decoder, kRefTypes, "imported mutable globals");
-        return;
-      }
-
-      LiftoffRegList pinned;
-      Register globals_buffer =
-          pinned.set(__ GetUnusedRegister(kGpReg, pinned)).gp();
-      LOAD_TAGGED_PTR_INSTANCE_FIELD(globals_buffer, TaggedGlobalsBuffer);
-      LiftoffRegister value = pinned.set(__ PopToRegister(pinned));
-      __ StoreTaggedPointer(globals_buffer, no_reg,
-                            wasm::ObjectAccess::ElementOffsetInTaggedFixedArray(
-                                imm.global->offset),
-                            value, pinned);
-      return;
-    }
     LiftoffRegList pinned;
     uint32_t offset = 0;
     Register addr = GetGlobalBaseAndOffset(global, &pinned, &offset);

src/wasm/baseline/mips/liftoff-assembler-mips.h

@@ -391,14 +391,6 @@ void LiftoffAssembler::LoadTaggedPointer(Register dst, Register src_addr,
        static_cast<uint32_t>(offset_imm), LoadType::kI32Load, pinned);
 }
 
-void LiftoffAssembler::StoreTaggedPointer(Register dst_addr,
-                                          Register offset_reg,
-                                          int32_t offset_imm,
-                                          LiftoffRegister src,
-                                          LiftoffRegList pinned) {
-  bailout(kRefTypes, "GlobalSet");
-}
-
 void LiftoffAssembler::Load(LiftoffRegister dst, Register src_addr,
                             Register offset_reg, uint32_t offset_imm,
                             LoadType type, LiftoffRegList pinned,

src/wasm/baseline/mips64/liftoff-assembler-mips64.h

@@ -355,14 +355,6 @@ void LiftoffAssembler::LoadTaggedPointer(Register dst, Register src_addr,
        static_cast<uint32_t>(offset_imm), LoadType::kI64Load, pinned);
 }
 
-void LiftoffAssembler::StoreTaggedPointer(Register dst_addr,
-                                          Register offset_reg,
-                                          int32_t offset_imm,
-                                          LiftoffRegister src,
-                                          LiftoffRegList pinned) {
-  bailout(kRefTypes, "GlobalSet");
-}
-
 void LiftoffAssembler::Load(LiftoffRegister dst, Register src_addr,
                             Register offset_reg, uint32_t offset_imm,
                             LoadType type, LiftoffRegList pinned,

src/wasm/baseline/ppc/liftoff-assembler-ppc.h

@@ -119,14 +119,6 @@ void LiftoffAssembler::LoadTaggedPointer(Register dst, Register src_addr,
   bailout(kUnsupportedArchitecture, "LoadTaggedPointer");
 }
 
-void LiftoffAssembler::StoreTaggedPointer(Register dst_addr,
-                                          Register offset_reg,
-                                          int32_t offset_imm,
-                                          LiftoffRegister src,
-                                          LiftoffRegList pinned) {
-  bailout(kRefTypes, "GlobalSet");
-}
-
 void LiftoffAssembler::Load(LiftoffRegister dst, Register src_addr,
                             Register offset_reg, uint32_t offset_imm,
                             LoadType type, LiftoffRegList pinned,

src/wasm/baseline/s390/liftoff-assembler-s390.h

@@ -118,14 +118,6 @@ void LiftoffAssembler::LoadTaggedPointer(Register dst, Register src_addr,
   bailout(kUnsupportedArchitecture, "LoadTaggedPointer");
 }
 
-void LiftoffAssembler::StoreTaggedPointer(Register dst_addr,
-                                          Register offset_reg,
-                                          int32_t offset_imm,
-                                          LiftoffRegister src,
-                                          LiftoffRegList pinned) {
-  bailout(kRefTypes, "GlobalSet");
-}
-
 void LiftoffAssembler::Load(LiftoffRegister dst, Register src_addr,
                             Register offset_reg, uint32_t offset_imm,
                             LoadType type, LiftoffRegList pinned,

src/wasm/baseline/x64/liftoff-assembler-x64.h

@@ -275,20 +275,6 @@ void LiftoffAssembler::LoadTaggedPointer(Register dst, Register src_addr,
   LoadTaggedPointerField(dst, src_op);
 }
 
-void LiftoffAssembler::StoreTaggedPointer(Register dst_addr,
-                                          Register offset_reg,
-                                          int32_t offset_imm,
-                                          LiftoffRegister src,
-                                          LiftoffRegList pinned) {
-  DCHECK_GE(offset_imm, 0);
-  if (emit_debug_code() && offset_reg != no_reg) {
-    AssertZeroExtended(offset_reg);
-  }
-  Operand dst_op = liftoff::GetMemOp(this, dst_addr, offset_reg,
-                                     static_cast<uint32_t>(offset_imm));
-  StoreTaggedField(dst_op, src.gp());
-}
-
 void LiftoffAssembler::AtomicLoad(LiftoffRegister dst, Register src_addr,
                                   Register offset_reg, uint32_t offset_imm,
                                   LoadType type, LiftoffRegList pinned) {

test/mjsunit/wasm/externref-globals-liftoff.js

-// Copyright 2020 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.
-
-// Flags: --experimental-wasm-reftypes --expose-gc --liftoff
-// Flags: --no-wasm-tier-up --liftoff-extern-ref
-
-load("test/mjsunit/wasm/externref-globals.js");