[llvm] [Offload][Conformance] Add `RandomGenerator` for large input spaces (PR #154252)

[Ross Brunton via llvm-commits]

================
@@ -33,73 +28,45 @@ namespace mathtest {
 
 template <typename... InTypes>
 class [[nodiscard]] ExhaustiveGenerator final
-    : public InputGenerator<InTypes...> {
-  static constexpr std::size_t NumInputs = sizeof...(InTypes);
-  static_assert(NumInputs > 0, "The number of inputs must be at least 1");
+    : public RangeBasedGenerator<ExhaustiveGenerator<InTypes...>, InTypes...> {
+
+  friend class RangeBasedGenerator<ExhaustiveGenerator<InTypes...>, InTypes...>;
+
+  using Base = RangeBasedGenerator<ExhaustiveGenerator<InTypes...>, InTypes...>;
+  using IndexArrayType = std::array<uint64_t, Base::NumInputs>;
+
+  using Base::InputSpaceSize;
+  using Base::RangesTuple;
+  using Base::SizeToGenerate;
 
 public:
   explicit constexpr ExhaustiveGenerator(
       const IndexedRange<InTypes> &...Ranges) noexcept
-      : RangesTuple(Ranges...) {
-    bool Overflowed = getSizeWithOverflow(Ranges..., Size);
-
-    assert(!Overflowed && "The input space size is too large");
-    assert((Size > 0) && "The input space size must be at least 1");
+      : Base(Ranges...) {
+    SizeToGenerate = InputSpaceSize;
 
     IndexArrayType DimSizes = {};
     std::size_t DimIndex = 0;
     ((DimSizes[DimIndex++] = Ranges.getSize()), ...);
 
-    Strides[NumInputs - 1] = 1;
-    if constexpr (NumInputs > 1)
-      for (int Index = static_cast<int>(NumInputs) - 2; Index >= 0; --Index)
+    Strides[Base::NumInputs - 1] = 1;
+    if constexpr (Base::NumInputs > 1)
+      for (int Index = static_cast<int>(Base::NumInputs) - 2; Index >= 0;
----------------
RossBrunton wrote:

`size_t` should be used when indexing arrays.

https://github.com/llvm/llvm-project/pull/154252