Factor out common vector crosstesting code.

crosstest/vectors.h

+//===- subzero/crosstest/vectors.h - Common SIMD vector utilies -*- C++ -*-===//
+//
+//                        The Subzero Code Generator
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file provides declarations for PNaCl portable SIMD vector types. In
+// addition, this file provides utilies that may be useful for crosstesting
+// vector code.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef VECTORS_H
+#define VECTORS_H
+
+#include <stdint.h>
+#include <string>
+#include <sstream>
+
+#include "vectors.def"
+
+// PNaCl portable vector types
+// Types declared: v4si32, v4ui32, v8si16, v8ui16, v16si8, v16ui8, v4f32
+#define X(ty, eltty, castty) typedef eltty ty __attribute__((vector_size(16)));
+VECTOR_TYPE_TABLE
+#undef X
+
+// i1 vector types are not native C++ SIMD vector types. Instead, for
+// testing, they are expanded by the test code into native 128 bit
+// SIMD vector types with the appropriate number of elements.
+// Representing the types in Vectors<> requires a unique label for each
+// type which this declaration provides.
+// Types declared: v4i1, v8i1, v16i1
+#define X(ty, expandedty, numelements) class ty;
+I1_VECTOR_TYPE_TABLE
+#undef X
+
+namespace {
+
+template <typename T> struct Vectors;
+
+// Vectors<T> provides information about a vector type with label T:
+// * Vectors<T>::Ty is the C++ vector type
+// * Vectors<T>::ElementTy is the C++ element type
+// * Vectors<T>::CastTy is a type that is safe to cast elements to and from
+//       and is used for getting the representation of elements in ostreams
+// * Vectors<T>::NumElements is the number of elements
+// * Vectors<T>::TypeName is a string that names the type
+
+#define DECLARE_VECTOR_TYPE(LABEL, TY, ELTTY, CASTTY, NUM_ELEMENTS)            \
+  template <> struct Vectors<LABEL> {                                          \
+    typedef TY Ty;                                                             \
+    typedef ELTTY ElementTy;                                                   \
+    typedef CASTTY CastTy;                                                     \
+    static const size_t NumElements;                                           \
+    static const char *const TypeName;                                         \
+  };                                                                           \
+  const size_t Vectors<LABEL>::NumElements = NUM_ELEMENTS;                     \
+  const char *const Vectors<LABEL>::TypeName = #LABEL;
+
+#define X(ty, eltty, castty)                                                   \
+  DECLARE_VECTOR_TYPE(ty, ty, eltty, castty, (sizeof(ty) / sizeof(eltty)))
+VECTOR_TYPE_TABLE
+#undef X
+
+#define X(ty, expandedty, numelements)                                         \
+  DECLARE_VECTOR_TYPE(ty, expandedty, bool, int64_t, numelements)
+I1_VECTOR_TYPE_TABLE
+#undef X
+
+#undef DECLARE_VECTOR_TYPE
+
+// Return a string representation of the vector.
+template <typename T>
+std::string vectAsString(const typename Vectors<T>::Ty Vect) {
+  std::ostringstream OS;
+  for (size_t i = 0; i < Vectors<T>::NumElements; ++i) {
+    if (i > 0)
+      OS << " ";
+    OS << (typename Vectors<T>::CastTy)Vect[i];
+  }
+  return OS.str();
+}
+
+// In some crosstests, test vectors are deterministically constructed by
+// selecting elements from a pool of scalar values based on a
+// pseudorandom sequence.  Testing all possible combinations of scalar
+// values from the value pool is often not tractable.
+//
+// TODO: Replace with a portable PRNG from C++11.
+class PRNG {
+public:
+  PRNG(uint32_t Seed = 1) : State(Seed) {}
+
+  uint32_t operator()() {
+    // Lewis, Goodman, and Miller (1969)
+    State = (16807 * State) % 2147483647;
+    return State;
+  }
+
+private:
+  uint32_t State;
+};
+
+} // end anonymous namespace
+
+#endif // VECTORS_H