Convert SIMD wasm ops to runtime function calls

src/compiler/simd-lowering.cc

+// Copyright 2016 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/compiler/simd-lowering.h"
+
+#include "src/assembler.h"
+#include "src/compiler/js-graph.h"
+#include "src/compiler/linkage.h"
+#include "src/compiler/machine-operator.h"
+#include "src/compiler/operator-properties.h"
+#include "src/compiler/simplified-operator.h"
+
+namespace v8 {
+namespace internal {
+namespace compiler {
+
+SimdLowering::~SimdLowering() {}
+
+Reduction SimdLowering::Reduce(Node* node) {
+  // For now lower everything to runtime calls.
+  switch (node->opcode()) {
+    case IrOpcode::kCreateInt32x4: {
+      Conversion signature[] = {kOpaque, kInt32, kInt32, kInt32, kInt32};
+      return ChangeToRuntimeCall(node, Runtime::kCreateInt32x4, signature);
+    }
+    case IrOpcode::kCreateInt16x8: {
+      Conversion signature[] = {

[titzer, 2016/05/19 09:58:38]

You can use "static const" here to make the C++ compiler move this to the
read-only data part of the binary.

[gdeepti, 2016/07/01 22:24:47]

Done.

+          kOpaque, kInt32, kInt32, kInt32, kInt32,
+          kInt32,  kInt32, kInt32, kInt32,
+      };
+      return ChangeToRuntimeCall(node, Runtime::kCreateInt16x8, signature);
+    }
+    case IrOpcode::kCreateInt8x16: {
+      Conversion signature[] = {
+          kOpaque, kInt32, kInt32, kInt32, kInt32, kInt32,
+          kInt32,  kInt32, kInt32, kInt32, kInt32, kInt32,
+          kInt32,  kInt32, kInt32, kInt32, kInt32,
+      };
+      return ChangeToRuntimeCall(node, Runtime::kCreateInt8x16, signature);
+    }
+    case IrOpcode::kCreateFloat32x4: {
+      Conversion signature[] = {kOpaque, kFloat32, kFloat32, kFloat32,
+                                kFloat32};
+      return ChangeToRuntimeCall(node, Runtime::kCreateFloat32x4, signature);
+    }
+    case IrOpcode::kInt8x16ExtractLane:
+    case IrOpcode::kInt16x8ExtractLane:
+    case IrOpcode::kInt32x4ExtractLane: {
+      Conversion signature[] = {kInt32, kOpaque, kInt32};
+      return ChangeToRuntimeCall(node, Runtime::kInt32x4ExtractLane, signature);
+    }
+    case IrOpcode::kFloat32x4ExtractLane: {
+      Conversion signature[] = {kFloat32, kOpaque, kInt32};
+      return ChangeToRuntimeCall(node, Runtime::kFloat32x4ExtractLane,
+                                 signature);
+    }
+    default: { break; }
+  }
+  // TODO(gdeepti): Implement and test.
+  // Assume the others are all just simd in and out.
+  switch (node->opcode()) {
+#define F(Opcode)                                                      \
+  case IrOpcode::k##Opcode: {                                          \
+    Conversion signature[17] = {                                       \
+        kNone, kNone, kNone, kNone, kNone, kNone, kNone, kNone, kNone, \
+        kNone, kNone, kNone, kNone, kNone, kNone, kNone, kNone,        \

[bbudge, 2016/05/19 09:53:13]

I'm not sure what the compiler does with this repeated in every block, but why
not move it outside the macro (and define it at top level function scope)?

[gdeepti, 2016/07/01 22:24:48]

Done.

+    };                                                                 \
+    return ChangeToRuntimeCall(node, Runtime::k##Opcode, signature);   \
+  }
+    MACHINE_SIMD_RETURN_SIMD_OP_LIST(F)
+    MACHINE_SIMD_RETURN_BOOL_OP_LIST(F)
+#undef F
+    default: { return NoChange(); }
+  }
+  UNREACHABLE();
+  return NoChange();
+}
+
+Reduction SimdLowering::ChangeToRuntimeCall(Node* node, Runtime::FunctionId f,
+                                            Conversion* signature) {
+  SimplifiedOperatorBuilder simplified(jsgraph()->zone());
+  const Runtime::Function* fun = Runtime::FunctionForId(f);
+  CallDescriptor* desc = Linkage::GetRuntimeCallDescriptor(
+      jsgraph()->zone(), f, fun->nargs, Operator::kNoProperties,
+      CallDescriptor::kNoFlags);
+  Node* inputs[16 + 6];

[bbudge, 2016/05/19 09:53:13]

Need some constants defined for these magic numbers, e.g.
kFunctionParams

[gdeepti, 2016/07/01 22:24:47]

Done.

+  DCHECK_LE(fun->nargs + 6, static_cast<int>(arraysize(inputs)));
+  // Either there are control + effect or not.
+  DCHECK(node->InputCount() == fun->nargs ||
+         node->InputCount() == fun->nargs + 2);
+  int index = 0;
+  inputs[index++] = jsgraph()->CEntryStubConstant(fun->result_size);
+  for (int i = 0; i < fun->nargs; ++i) {
+    Node* arg = node->InputAt(i);
+    switch (signature[i + 1]) {
+      case kInt32:
+        arg = builder_->BuildChangeInt32ToTagged(arg);
+        break;
+      case kFloat32:
+        arg = jsgraph()->graph()->NewNode(
+            jsgraph()->machine()->ChangeFloat32ToFloat64(), arg);
+        arg = builder_->BuildChangeFloat64ToTagged(arg);
+        break;
+      case kFloat64:
+        arg = builder_->BuildChangeFloat64ToTagged(arg);
+        break;
+      default:
+        break;
+    }
+    inputs[index++] = arg;
+  }
+  inputs[index++] =
+      jsgraph()->ExternalConstant(ExternalReference(f, jsgraph()->isolate()));
+  inputs[index++] = jsgraph()->Int32Constant(fun->nargs);
+  inputs[index++] = jsgraph()->Constant(context_);
+  // Loads and stores have control and effect, others do not and use
+  // the start node instead.
+  if (node->InputCount() == fun->nargs + 2) {
+    inputs[index++] = node->InputAt(fun->nargs + 1);  // effect
+    inputs[index++] = node->InputAt(fun->nargs + 2);  // control
+  } else {
+    inputs[index++] = jsgraph()->graph()->start();  // effect
+    inputs[index++] = jsgraph()->graph()->start();  // control
+  }
+  Node* ret = jsgraph()->graph()->NewNode(jsgraph()->common()->Call(desc),
+                                          index, inputs);
+  switch (signature[0]) {

[bbudge, 2016/05/19 09:53:14]

Maybe this would benefit with a well named local, i.e.
Conversion return_type = signature[0];
switch (return_type) ...

[gdeepti, 2016/07/01 22:24:47]

Done.

+    case kInt32:
+      ret = builder_->BuildChangeTaggedToInt32(ret);
+      break;
+    case kFloat32:
+      NodeProperties::SetType(ret, Type::Number());
+      ret = builder_->BuildChangeTaggedToFloat64(ret);
+      ret = jsgraph()->graph()->NewNode(
+          jsgraph()->machine()->TruncateInt64ToInt32(), ret);
+      break;
+    case kFloat64:
+      ret = builder_->BuildChangeTaggedToFloat64(ret);
+      break;
+    default:
+      break;
+  }
+  return Replace(ret);
+}
+
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8