SIMD plumbing

runtime/vm/locations.h

Index: runtime/vm/locations.h
diff --git a/runtime/vm/locations.h b/runtime/vm/locations.h
index 6a8dda865d28d5cbf8c299964ae3177304306690..9a2884831a6145b2ca49121cb5a59fa23997c5d3 100644
--- a/runtime/vm/locations.h
+++ b/runtime/vm/locations.h
@@ -27,7 +27,7 @@ class Location : public ValueObject {
  private:
   enum {
     // Number of bits required to encode Kind value.
-    kBitsForKind = 3,
+    kBitsForKind = 4,
     kBitsForPayload = kWordSize * kBitsPerByte - kBitsForKind,
   };
 
@@ -58,6 +58,8 @@ class Location : public ValueObject {
     // a spill index.
     kStackSlot = 3,
     kDoubleStackSlot = 4,
+    kFloat32x4StackSlot = 8,
+    kUint32x4StackSlot = 9,

[Vyacheslav Egorov (Google), 2013/03/17 18:17:10]

It can't be 9 (see the comment above enum Kind).

[Cutch, 2013/03/17 21:52:37]

Done.

 
     // Register location represents a fixed register.  Payload contains
     // register code.
@@ -176,15 +178,18 @@ class Location : public ValueObject {
     return RegisterField::decode(payload());
   }
 
-  // FPU registers and double spill slots can contain either doubles
-  // or 64-bit integers.
+  // FPU registers and double spill slots can contain either doubles,
+  // 64-bit integers, Float32x4, or Uint32x4 values.
   enum Representation {
     kDouble,
-    kMint
+    kMint,
+    kFloat32x4,
+    kUint32x4
   };
 
   Representation representation() const {
-    ASSERT(IsFpuRegister() || IsDoubleStackSlot());
+    ASSERT(IsFpuRegister() ||IsDoubleStackSlot() || IsFloat32x4StackSlot() ||
+           IsUint32x4StackSlot());
     return RepresentationField::decode(payload());
   }
 
@@ -262,9 +267,42 @@ class Location : public ValueObject {
     return kind() == kDoubleStackSlot;
   }
 
+  static Location Float32x4StackSlot(intptr_t stack_index, Representation rep) {
+    ASSERT((-kStackIndexBias <= stack_index) &&
+           (stack_index < kStackIndexBias));
+    uword payload =
+        IndexField::encode(static_cast<uword>(kStackIndexBias + stack_index))

[Vyacheslav Egorov (Google), 2013/03/17 18:17:10]

encoding of stack indexes repeats multiple times. consider introducing a helper.

[Cutch, 2013/03/17 21:52:37]

Done.

+      | RepresentationField::encode(rep);
+    Location loc(kFloat32x4StackSlot, payload);
+    // Ensure that sign is preserved.
+    ASSERT(loc.stack_index() == stack_index);
+    return loc;
+  }
+
+  bool IsFloat32x4StackSlot() const {
+    return kind() == kFloat32x4StackSlot;
+  }
+
+  static Location Uint32x4StackSlot(intptr_t stack_index, Representation rep) {
+    ASSERT((-kStackIndexBias <= stack_index) &&
+           (stack_index < kStackIndexBias));
+    uword payload =
+        IndexField::encode(static_cast<uword>(kStackIndexBias + stack_index))
+      | RepresentationField::encode(rep);
+    Location loc(kUint32x4StackSlot, payload);
+    // Ensure that sign is preserved.
+    ASSERT(loc.stack_index() == stack_index);
+    return loc;
+  }
+
+  bool IsUint32x4StackSlot() const {
+    return kind() == kUint32x4StackSlot;
+  }
+
 
   intptr_t stack_index() const {
-    ASSERT(IsStackSlot() || IsDoubleStackSlot());
+    ASSERT(IsStackSlot() || IsDoubleStackSlot() || IsFloat32x4StackSlot() ||
+           IsUint32x4StackSlot());
     // Decode stack index manually to preserve sign.
     return IndexField::decode(payload()) - kStackIndexBias;
   }
@@ -312,7 +350,7 @@ class Location : public ValueObject {
 
   // Layout for register locations payload. The representation bit is only used
   // for FpuRegister and unused for Register.
-  static const intptr_t kBitsForRepresentation = 1;
+  static const intptr_t kBitsForRepresentation = 2;
   static const intptr_t kBitsForRegister =
       kBitsForPayload - kBitsForRepresentation;
   typedef BitField<Representation,