Revert "[wasm] Support encoding s128 simd types in exceptions."

This reverts commit 9c2c8f15.

Reason for revert: New test crashes: https://ci.chromium.org/p/v8/builders/luci.v8.ci/V8%20Linux/28948

Original change's description:
> [wasm] Support encoding s128 simd types in exceptions.
> 
> This adds support for having simd type values (i.e. s128) stored in an
> exception. It is the natural combination of the simd propsal and the
> exception handling proposal.
> 
> R=​clemensh@chromium.org
> TEST=mjsunit/wasm/exceptions-simd
> BUG=v8:8390
> 
> Change-Id: I01079f82a6ba4d9152de4dae63e3db1584ca7cd8
> Reviewed-on: https://chromium-review.googlesource.com/c/1363141
> Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
> Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#58098}

TBR=mstarzinger@chromium.org,gdeepti@chromium.org,clemensh@chromium.org

Change-Id: Iedcfba36af925249131a2b0e9aebd92321ae72f5
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:8390
Reviewed-on: https://chromium-review.googlesource.com/c/1367808Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58102}

src/compiler/backend/arm/instruction-selector-arm.cc

@@ -2466,7 +2466,7 @@ void InstructionSelector::VisitWord32AtomicPairCompareExchange(Node* node) {
 
 void InstructionSelector::VisitS128Zero(Node* node) {
   ArmOperandGenerator g(this);
-  Emit(kArmS128Zero, g.DefineAsRegister(node));
+  Emit(kArmS128Zero, g.DefineAsRegister(node), g.DefineAsRegister(node));
 }
 
 #define SIMD_VISIT_SPLAT(Type)                               \

src/compiler/backend/arm64/instruction-selector-arm64.cc

@@ -3009,7 +3009,7 @@ void InstructionSelector::VisitInt64AbsWithOverflow(Node* node) {
 
 void InstructionSelector::VisitS128Zero(Node* node) {
   Arm64OperandGenerator g(this);
-  Emit(kArm64S128Zero, g.DefineAsRegister(node));
+  Emit(kArm64S128Zero, g.DefineAsRegister(node), g.DefineAsRegister(node));
 }
 
 #define SIMD_VISIT_SPLAT(Type)                               \

src/compiler/backend/x64/instruction-selector-x64.cc

@@ -2628,7 +2628,7 @@ VISIT_ATOMIC_BINOP(Xor)
 
 void InstructionSelector::VisitS128Zero(Node* node) {
   X64OperandGenerator g(this);
-  Emit(kX64S128Zero, g.DefineAsRegister(node));
+  Emit(kX64S128Zero, g.DefineAsRegister(node), g.DefineAsRegister(node));
 }
 
 #define VISIT_SIMD_SPLAT(Type)                               \

src/compiler/wasm-compiler.cc

@@ -2101,8 +2101,8 @@ uint32_t WasmGraphBuilder::GetExceptionEncodedSize(
         encoded_size += 4;
         break;
       case wasm::kWasmS128:
-        DCHECK_EQ(8, ComputeEncodedElementSize(sig->GetParam(i)));
-        encoded_size += 8;
+        // TODO(mstarzinger): Implement and test this case.
+        UNIMPLEMENTED();
         break;
       case wasm::kWasmAnyRef:
         encoded_size += 1;
@@ -2151,20 +2151,6 @@ Node* WasmGraphBuilder::Throw(uint32_t exception_index,
         BuildEncodeException32BitValue(values_array, &index, lower32);
         break;
       }
-      case wasm::kWasmS128:
-        BuildEncodeException32BitValue(
-            values_array, &index,
-            graph()->NewNode(m->I32x4ExtractLane(0), value));
-        BuildEncodeException32BitValue(
-            values_array, &index,
-            graph()->NewNode(m->I32x4ExtractLane(1), value));
-        BuildEncodeException32BitValue(
-            values_array, &index,
-            graph()->NewNode(m->I32x4ExtractLane(2), value));
-        BuildEncodeException32BitValue(
-            values_array, &index,
-            graph()->NewNode(m->I32x4ExtractLane(3), value));
-        break;
       case wasm::kWasmAnyRef:
         STORE_FIXED_ARRAY_SLOT_ANY(values_array, index, value);
         ++index;
@@ -2283,20 +2269,6 @@ Node** WasmGraphBuilder::GetExceptionValues(
                      BuildDecodeException64BitValue(values_array, &index));
         break;
       }
-      case wasm::kWasmS128:
-        value = graph()->NewNode(
-            mcgraph()->machine()->I32x4Splat(),
-            BuildDecodeException32BitValue(values_array, &index));
-        value = graph()->NewNode(
-            mcgraph()->machine()->I32x4ReplaceLane(1), value,
-            BuildDecodeException32BitValue(values_array, &index));
-        value = graph()->NewNode(
-            mcgraph()->machine()->I32x4ReplaceLane(2), value,
-            BuildDecodeException32BitValue(values_array, &index));
-        value = graph()->NewNode(
-            mcgraph()->machine()->I32x4ReplaceLane(3), value,
-            BuildDecodeException32BitValue(values_array, &index));
-        break;
       case wasm::kWasmAnyRef:
         value = LOAD_FIXED_ARRAY_SLOT_ANY(values_array, index);
         ++index;

test/mjsunit/wasm/exceptions-simd.js

-// Copyright 2018 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: --expose-wasm --experimental-wasm-eh --experimental-wasm-simd --allow-natives-syntax
-
-load("test/mjsunit/wasm/wasm-constants.js");
-load("test/mjsunit/wasm/wasm-module-builder.js");
-
-//TODO(mstarzinger): Duplicated in the exceptions.js file. Dedupe.
-function assertWasmThrows(instance, runtime_id, values, code) {
-  try {
-    if (typeof code === 'function') {
-      code();
-    } else {
-      eval(code);
-    }
-  } catch (e) {
-    assertInstanceof(e, WebAssembly.RuntimeError);
-    var e_runtime_id = %GetWasmExceptionId(e, instance);
-    assertTrue(Number.isInteger(e_runtime_id));
-    assertEquals(e_runtime_id, runtime_id);
-    var e_values = %GetWasmExceptionValues(e);
-    assertArrayEquals(values, e_values);
-    return;  // Success.
-  }
-  throw new MjsUnitAssertionError('Did not throw expected <' + runtime_id +
-                                  '> with values: ' + values);
-}
-
-(function TestThrowS128Default() {
-  var builder = new WasmModuleBuilder();
-  var kSig_v_s = makeSig([kWasmS128], []);
-  var except = builder.addException(kSig_v_s);
-  builder.addFunction("throw_simd", kSig_v_v)
-      .addLocals({s128_count: 1})
-      .addBody([
-        kExprGetLocal, 0,
-        kExprThrow, 0,
-      ])
-      .exportFunc();
-  var instance = builder.instantiate();
-
-  assertWasmThrows(instance, except, [0, 0, 0, 0, 0, 0, 0, 0],
-                   () => instance.exports.throw_simd());
-})();
-
-(function TestThrowCatchS128Default() {
-  var builder = new WasmModuleBuilder();
-  var kSig_v_s = makeSig([kWasmS128], []);
-  var except = builder.addException(kSig_v_s);
-  builder.addFunction("throw_catch_simd", kSig_i_v)
-      .addLocals({s128_count: 1})
-      .addBody([
-        kExprTry, kWasmI32,
-          kExprGetLocal, 0,
-          kExprThrow, 0,
-        kExprCatch, except,
-        // TODO(mstarzinger): Actually return some compressed form of the s128
-        // value here to make sure it is extracted properly from the exception.
-          kExprDrop,
-          kExprI32Const, 1,
-        kExprEnd,
-      ])
-      .exportFunc();
-  var instance = builder.instantiate();
-
-  assertEquals(1, instance.exports.throw_catch_simd());
-})();