[SubZero] Vector types support for MIPS

src/IceOperand.h

 //===- subzero/src/IceOperand.h - High-level operands -----------*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 34 matching lines @@
     kConstInteger32,
     kConstInteger64,
     kConstFloat,
     kConstDouble,
     kConstRelocatable,
     kConstUndef,
     kConst_Target, // leave space for target-specific constant kinds
     kConst_Max = kConst_Target + MaxTargetKinds,
     kVariable,
     kVariable64On32,
+    kVariableVecOn32,
     kVariableBoolean,
     kVariable_Target, // leave space for target-specific variable kinds
     kVariable_Max = kVariable_Target + MaxTargetKinds,
     // Target-specific operand classes use kTarget as the starting point for
     // their Kind enum space. Note that the value-spaces are shared across
     // targets. To avoid confusion over the definition of shared values, an
     // object specific to one target should never be passed to a different
     // target.
     kTarget,
     kTarget_Max = std::numeric_limits<uint8_t>::max(),
@@ skipping 890 matching lines @@
 protected:
   Variable64On32(const Cfg *Func, OperandKind K, Type Ty, SizeT Index)
       : Variable(Func, K, Ty, Index) {
     assert(typeWidthInBytes(Ty) == 8);
   }
 
   Variable *LoVar = nullptr;
   Variable *HiVar = nullptr;
 };
 
+// VariableVecOn32 represents a vector variable on a 32-bit architecture. In

[Jim Stichnoth, 2016/09/30 15:41:59]

How about:
  ... represents a 128-bit vector variable ...

so that the number 4 is more clear

[jaydeep.patil, 2016/10/03 06:38:55]

Done.

+// this situation the variable must be split into 4 containers.
+class VariableVecOn32 : public Variable {
+  VariableVecOn32() = delete;
+  VariableVecOn32(const VariableVecOn32 &) = delete;
+  VariableVecOn32 &operator=(const VariableVecOn32 &) = delete;
+

[Jim Stichnoth, 2016/09/30 15:41:59]

In this private section, could you define a static constexpr variable describing
the number of container elements per vector value?  e.g.

  // A 128-bit vector value is mapped onto 4 32-bit register values.
  static constexpr SizeT ElementsPerContainer = 4;

[Jim Stichnoth, 2016/09/30 17:37:40]

Actually, maybe it would be better to put this constexpr into the public
section, so that many/most of the uses of "4" in the target lowering code could
use that constexpr instead.

[jaydeep.patil, 2016/10/03 06:38:55]

Done.

[jaydeep.patil, 2016/10/03 06:38:56]

Acknowledged.

+public:
+  static VariableVecOn32 *create(Cfg *Func, Type Ty, SizeT Index) {
+    return new (Func->allocate<VariableVecOn32>())
+        VariableVecOn32(Func, kVariableVecOn32, Ty, Index);
+  }
+
+  void setName(const Cfg *Func, const std::string &NewName) override {
+    Variable::setName(Func, NewName);
+    if (!Containers.empty()) {

[Jim Stichnoth, 2016/09/30 15:41:58]

I think you can remove the .empty() test.

[jaydeep.patil, 2016/10/03 06:38:56]

We need this check here. We may not have called initVecElement (like initHiLo
for instance).

+      for (SizeT i = 0; i < Containers.size(); ++i) {
+        Containers[i]->setName(Func, getName() + "__cont" + std::to_string(i));
+      }
+    }
+  }
+
+  void setIsArg(bool Val = true) override {
+    Variable::setIsArg(Val);
+    if (!Containers.empty()) {

[Jim Stichnoth, 2016/09/30 15:41:59]

Definitely remove the .empty() test here.

[jaydeep.patil, 2016/10/03 06:38:56]

Done.

+      for (Variable *Var : Containers) {
+        Var->setIsArg(getIsArg());
+      }
+    }
+  }
+
+  const VarList &getContainers() const { return Containers; }
+
+  void initVecElement(Cfg *Func, Type VecType) {
+    VectorType = VecType;
+    for (SizeT i = 0; i < 4; ++i) {

[Jim Stichnoth, 2016/09/30 15:41:58]

... i < ElementsPerContainer; ...

[jaydeep.patil, 2016/10/03 06:38:56]

Done.

+      Variable *Var = Func->makeVariable(IceType_i32);
+      Var->setIsArg(getIsArg());
+      if (BuildDefs::dump()) {
+        Var->setName(Func, getName() + "__cont" + std::to_string(i));
+      }
+      Containers.push_back(Var);
+    }
+  }
+
+  static bool classof(const Operand *Operand) {
+    OperandKind Kind = Operand->getKind();
+    return Kind == kVariableVecOn32;
+  }
+
+protected:
+  VariableVecOn32(const Cfg *Func, OperandKind K, Type Ty, SizeT Index)
+      : Variable(Func, K, Ty, Index) {
+    assert(typeWidthInBytes(Ty) == 16);

[Jim Stichnoth, 2016/09/30 15:41:59]

Instead of "16", maybe
  ElementsPerContainer * typeWidthInBytes(IceType_i32)

[jaydeep.patil, 2016/10/03 06:38:55]

Done.

+  }
+
+  VarList Containers;
+  Type VectorType;

[Jim Stichnoth, 2016/09/30 15:41:59]

It doesn't look like this field is actually used anywhere.  Can you remove it?

[jaydeep.patil, 2016/10/03 06:38:56]

Done.

+};
+
 enum MetadataKind {
   VMK_Uses,       /// Track only uses, not defs
   VMK_SingleDefs, /// Track uses+defs, but only record single def
   VMK_All         /// Track uses+defs, including full def list
 };
 using InstDefList = CfgVector<const Inst *>;
 
 /// VariableTracking tracks the metadata for a single variable.  It is
 /// only meant to be used internally by VariablesMetadata.
 class VariableTracking {
@@ skipping 128 matching lines @@
     return Operand->getKind() == kVariableBoolean;
   }
 
 private:
   Variable *BoolSource = nullptr;
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICEOPERAND_H