Convert SIMD wasm ops to runtime function calls

src/wasm/ast-decoder.cc

 // Copyright 2015 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/signature.h"
 
 #include "src/bit-vector.h"
 #include "src/flags.h"
 #include "src/handles.h"
 #include "src/zone-containers.h"
@@ skipping 978 matching lines @@
             CallImportOperand operand(this, pc_);
             if (Validate(pc_, operand)) {
               TFNode** buffer = PopArgs(operand.sig);
               TFNode* call =
                   BUILD(CallImport, operand.index, buffer, position());
               Push(GetReturnType(operand.sig), call);
             }
             len = 1 + operand.length;
             break;
           }
+          case kSimdPrefix: {
+            len++;
+            byte simd_index = *(pc_ + 1);
+            opcode = static_cast<WasmOpcode>(opcode << 8 | simd_index);
+            DecodeSimdOpcode(opcode);

[bradnelson, 2016/07/13 18:10:42]

Add an --enable-wasm-simd flag, and error if this shows up without it on.

[gdeepti, 2016/07/13 18:58:35]

Added --enable-wasm-simd flag, falls through to invalid opcode case without the
flag. 

+            break;
+          }
           default:
             error("Invalid opcode");
             return;
         }
       }  // end complex bytecode
 
 #if DEBUG
       if (FLAG_trace_wasm_decoder) {
         for (size_t i = 0; i < stack_.size(); ++i) {
           Value& val = stack_[i];
@@ skipping 85 matching lines @@
   int DecodeStoreMem(LocalType type, MachineType mem_type) {
     MemoryAccessOperand operand(this, pc_);
     Value val = Pop(1, type);
     Value index = Pop(0, kAstI32);
     BUILD(StoreMem, mem_type, index.node, operand.offset, operand.alignment,
           val.node, position());
     Push(type, val.node);
     return 1 + operand.length;
   }
 
+  void DecodeSimdOpcode(WasmOpcode opcode) {
+    FunctionSig* sig = WasmOpcodes::Signature(opcode);
+    compiler::NodeVector inputs(sig->parameter_count(), zone_);
+    for (int i = static_cast<int>(sig->parameter_count()); i > 0; i--) {

[bradnelson, 2016/07/13 18:10:42]

size_t drop cast?

[gdeepti, 2016/07/13 18:58:35]

Done.

+      Value val = Pop(i - 1, sig->GetParam(i - 1));
+      inputs[i - 1] = val.node;
+    }
+    TFNode* node = BUILD(SimdOp, opcode, inputs);
+    Push(GetReturnType(sig), node);
+  }
+
   void DoReturn() {
     int count = static_cast<int>(sig_->return_count());
     TFNode** buffer = nullptr;
     if (build()) buffer = builder_->Buffer(count);
 
     // Pop return values off the stack in reverse order.
     for (int i = count - 1; i >= 0; i--) {
       Value val = Pop(i, sig_->GetReturn(i));
       if (buffer) buffer[i] = val.node;
     }
@@ skipping 524 matching lines @@
 BitVector* AnalyzeLoopAssignmentForTesting(Zone* zone, size_t num_locals,
                                            const byte* start, const byte* end) {
   FunctionBody body = {nullptr, nullptr, nullptr, start, end};
   WasmFullDecoder decoder(zone, nullptr, body);
   return decoder.AnalyzeLoopAssignmentForTesting(start, num_locals);
 }
 
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8