feat: Add exact verifier

Add a verifier to check that tensor results match exactly.
Add a unit test to check the behavior of this new verifier.

Change-Id: I9b80a6d57640fec67c6be80a97b3af484aeb935e
Signed-off-by: Jack Frankland <jack.frankland@arm.com>

7 files changed, 188 insertions, 13 deletions

diff --git a/reference_model/CMakeLists.txt b/reference_model/CMakeLists.txt
index 88192bf..5facfe1 100644
--- a/reference_model/CMakeLists.txt
+++ b/reference_model/CMakeLists.txt
@@ -73,6 +73,7 @@ set(CXX_SOURCE
     src/tensor.cc
     src/verify/verify_dot_product.cc
     src/verify/verify_entry.cc
+    src/verify/verify_exact.cc
     src/verify/verify_utils.cc
     src/ops/op_factory.cc
     src/ops/tensor_ops.cc
@@ -141,6 +142,7 @@ set_target_properties(tosa_reference_model_lib PROPERTIES PUBLIC_HEADER "${PUBLI
 add_library(tosa_reference_verify_lib SHARED
   src/verify/verify_dot_product.cc
   src/verify/verify_entry.cc
+  src/verify/verify_exact.cc
   src/verify/verify_utils.cc
   src/verify/verify_config.cc
   src/func_debug.cc
@@ -248,4 +250,4 @@ install(EXPORT TosaReferenceModelLibTargets
   FILE TosaReferenceModelLibTargets.cmake
   NAMESPACE TosaReference::
   DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/tosa_reference_model_lib"
-)
\ No newline at end of file
+)
diff --git a/reference_model/src/verify/verifiers.h b/reference_model/src/verify/verifiers.h
index afd50bf..177eeaf 100644
--- a/reference_model/src/verify/verifiers.h
+++ b/reference_model/src/verify/verifiers.h
@@ -33,6 +33,14 @@ bool verifyDotProduct(const CTensor* ref,
                       const CTensor* imp,
                       const DotProductVerifyInfo& dpInfo);
 
+/// \brief Perform exact result verification
+///
+/// \param referenceTensor    Reference tensor
+/// \param implementationTensor    Implementation resulting tensor
+///
+/// \return True if compliant else false
+bool verifyExact(const CTensor* referenceTensor, const CTensor* implementationTensor);
+
 };    // namespace TosaReference
 
 #endif    // VERIFIERS_H_
diff --git a/reference_model/src/verify/verify_dot_product.cc b/reference_model/src/verify/verify_dot_product.cc
index 0b05c92..a96befa 100644
--- a/reference_model/src/verify/verify_dot_product.cc
+++ b/reference_model/src/verify/verify_dot_product.cc
@@ -20,13 +20,6 @@
 #include <optional>
 #include <type_traits>
 
-#define TOSA_REF_REQUIRE(COND, MESSAGE)                                                                                \
-    if (!(COND))                                                                                                       \
-    {                                                                                                                  \
-        WARNING(MESSAGE);                                                                                              \
-        return false;                                                                                                  \
-    }
-
 namespace TosaReference
 {
 namespace
@@ -139,5 +132,3 @@ bool verifyDotProduct(const CTensor* ref, const CTensor* refBnd, const CTensor*
 }
 
 }    // namespace TosaReference
-
-#undef TOSA_REF_REQUIRE
\ No newline at end of file
diff --git a/reference_model/src/verify/verify_entry.cc b/reference_model/src/verify/verify_entry.cc
index 80ca916..1c48354 100644
--- a/reference_model/src/verify/verify_entry.cc
+++ b/reference_model/src/verify/verify_entry.cc
@@ -30,7 +30,9 @@ bool verify(const CTensor* ref, const CTensor* refBnd, const CTensor* imp, const
     {
         case VerifyMode::DotProduct: {
             return verifyDotProduct(ref, refBnd, imp, cfg.dotProductInfo);
-            break;
+        }
+        case VerifyMode::Exact: {
+            return verifyExact(ref, imp);
         }
         default: {
             WARNING("unsupported verification mode.");
diff --git a/reference_model/src/verify/verify_exact.cc b/reference_model/src/verify/verify_exact.cc
new file mode 100644
index 0000000..7fde5bb
--- /dev/null
+++ b/reference_model/src/verify/verify_exact.cc
@@ -0,0 +1,53 @@
+// Copyright (c) 2023, ARM Limited.
+//
+//    Licensed under the Apache License, Version 2.0 (the "License");
+//    you may not use this file except in compliance with the License.
+//    You may obtain a copy of the License at
+//
+//         http://www.apache.org/licenses/LICENSE-2.0
+//
+//    Unless required by applicable law or agreed to in writing, software
+//    distributed under the License is distributed on an "AS IS" BASIS,
+//    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//    See the License for the specific language governing permissions and
+//    limitations under the License.
+
+#include "func_debug.h"
+#include "verifiers.h"
+#include <cmath>
+
+namespace TosaReference
+{
+
+bool verifyExact(const CTensor* referenceTensor, const CTensor* implementationTensor)
+{
+    // Validate that tensors are provided
+    TOSA_REF_REQUIRE(referenceTensor != nullptr, "reference tensor is missing");
+    TOSA_REF_REQUIRE(implementationTensor != nullptr, "implementation tensor is missing");
+
+    // Get number of elements
+    const auto elementCount =
+        numElements(std::vector<int32_t>(referenceTensor->shape, referenceTensor->shape + referenceTensor->num_dims));
+    TOSA_REF_REQUIRE(elementCount > 0, "invalid shape for reference tensor");
+
+    switch (implementationTensor->data_type)
+    {
+        case tosa_datatype_fp32_t: {
+            const auto* refData = reinterpret_cast<const float*>(referenceTensor->data);
+            TOSA_REF_REQUIRE(refData != nullptr, "missing data for reference");
+            const auto* impData = reinterpret_cast<const float*>(implementationTensor->data);
+            TOSA_REF_REQUIRE(impData != nullptr, "missing data for implementation");
+            return std::equal(refData, std::next(refData, elementCount), impData, std::next(impData, elementCount),
+                              [](const auto& referenceValue, const auto& implementationValue) {
+                                  return std::isnan(referenceValue) ? std::isnan(implementationValue)
+                                                                    : (referenceValue == implementationValue);
+                              });
+        }
+        default:
+            WARNING("data-type not supported.");
+            break;
+    }
+
+    return false;
+}
+}    // namespace TosaReference
diff --git a/reference_model/src/verify/verify_utils.h b/reference_model/src/verify/verify_utils.h
index 6e51e3e..3a527da 100644
--- a/reference_model/src/verify/verify_utils.h
+++ b/reference_model/src/verify/verify_utils.h
@@ -23,6 +23,13 @@
 #include <optional>
 #include <vector>
 
+#define TOSA_REF_REQUIRE(COND, MESSAGE)                                                                                \
+    if (!(COND))                                                                                                       \
+    {                                                                                                                  \
+        WARNING(MESSAGE);                                                                                              \
+        return false;                                                                                                  \
+    }
+
 namespace TosaReference
 {
 
diff --git a/reference_model/test/verify_tests.cpp b/reference_model/test/verify_tests.cpp
index 81f3e8d..731a808 100644
--- a/reference_model/test/verify_tests.cpp
+++ b/reference_model/test/verify_tests.cpp
@@ -13,10 +13,16 @@
 //    limitations under the License.
 #include "verify.h"
 
+#include <algorithm>
 #include <doctest.h>
 
 #include <array>
+#include <iterator>
+#include <limits>
+#include <numeric>
+#include <random>
 #include <string>
+#include <type_traits>
 #include <vector>
 
 namespace
@@ -25,7 +31,7 @@ namespace
 class TosaTensor
 {
 public:
-    TosaTensor(std::string name, tosa_datatype_t dataType, std::vector<int32_t> shape)
+    TosaTensor(std::string name, tosa_datatype_t dataType, std::vector<int32_t> shape, uint8_t* data = nullptr)
         : _name(std::move(name))
         , _shape(std::move(shape))
     {
@@ -33,6 +39,9 @@ public:
         _tensor.data_type = dataType;
         _tensor.num_dims  = _shape.size();
         _tensor.shape     = _shape.data();
+        _tensor.data      = data;
+        _tensor.size =
+            std::accumulate(_tensor.shape, std::next(_tensor.shape, _tensor.num_dims), 1, std::multiplies<>());
     };
 
     const tosa_tensor_t* cTensor() const
@@ -46,6 +55,66 @@ private:
     tosa_tensor_t _tensor;
 };
 
+auto& getRandomGenerator()
+{
+    static std::mt19937 gen(0);
+    return gen;
+}
+
+template <typename FP>
+std::enable_if_t<std::is_floating_point_v<FP>, std::add_lvalue_reference_t<std::uniform_real_distribution<FP>>>
+    getUniformRealDist()
+{
+    // Uniform real distribution generates real values in the range [a, b)
+    // and requires that b - a <= std::numeric_limits<FP>::max() so here
+    // we choose some arbitrary values that satisfy that condition.
+    constexpr auto min = std::numeric_limits<FP>::lowest() / 2;
+    constexpr auto max = std::numeric_limits<FP>::max() / 2;
+    static_assert(max <= std::numeric_limits<FP>::max() + min);
+
+    static std::uniform_real_distribution<FP> dis(min, max);
+    return dis;
+}
+
+template <typename FP>
+std::enable_if_t<std::is_floating_point_v<FP>, FP> getRandomUniformFloat()
+{
+    return getUniformRealDist<FP>()(getRandomGenerator());
+}
+
+template <typename FP>
+std::enable_if_t<std::is_floating_point_v<FP>, std::vector<FP>> generateRandomTensorData(size_t elementCount,
+                                                                                         bool includeNans = false)
+{
+    // Generate some random floats using the full range of fp32.
+    auto data = std::vector<FP>(elementCount);
+    std::generate(std::begin(data), std::end(data), []() { return getRandomUniformFloat<FP>(); });
+
+    // Include some edge cases.
+    auto edgeCases = std::vector<float>{ +0.0f, -0.0f, std::numeric_limits<float>::infinity(),
+                                         -std::numeric_limits<float>::infinity() };
+    if (includeNans)
+    {
+        static const auto nans =
+            std::vector<float>{ std::numeric_limits<float>::quiet_NaN(), std::numeric_limits<float>::signaling_NaN() };
+
+        std::copy(std::begin(nans), std::end(nans), std::back_inserter(edgeCases));
+    }
+
+    if (elementCount >= edgeCases.size())
+    {
+        // Evenly distribute the edge cases throughout the data, this way for operations like reductions all edge cases won't
+        // end up in the same row/column over which a reduction happens.
+        const auto stride = (data.size() + (edgeCases.size() - 1)) / edgeCases.size();
+        for (unsigned i = 0; i < edgeCases.size(); ++i)
+        {
+            data[i * stride] = edgeCases[i];
+        }
+    }
+
+    return data;
+}
+
 }    // namespace
 
 TEST_SUITE_BEGIN("verify");
@@ -115,4 +184,47 @@ TEST_CASE("negative - api")
     }
 }
 
-TEST_SUITE_END();    // verify
\ No newline at end of file
+TEST_CASE("positive - exact")
+{
+    std::string json_cfg = R"({
+        "tensors" : {
+            "out1" : {
+                "mode": "EXACT"
+            }
+        }
+    })";
+
+    const auto shape        = std::vector<int32_t>{ 8, 8, 8 };
+    const auto elementCount = std::accumulate(std::begin(shape), std::end(shape), 1, std::multiplies<>());
+
+    // Generate some random floats using the full range of fp32.
+    auto data = generateRandomTensorData<float>(elementCount);
+    SUBCASE("same")
+    {
+        const auto referenceTensor =
+            TosaTensor("out1", tosa_datatype_fp64_t, shape, reinterpret_cast<uint8_t*>(data.data()));
+        const auto implementationTensor =
+            TosaTensor("out1", tosa_datatype_fp32_t, shape, reinterpret_cast<uint8_t*>(data.data()));
+        REQUIRE(tvf_verify_data(referenceTensor.cTensor(), nullptr, implementationTensor.cTensor(), json_cfg.c_str()));
+    }
+
+    SUBCASE("different")
+    {
+        // Generate some mismatched tensors by setting every other value to an incrementing counter.
+        // In theory this could be the same, but the probability is tiny.
+        auto otherData = std::vector<float>(elementCount);
+        std::generate(std::begin(otherData), std::end(otherData), [&, i = 0]() mutable {
+            auto oldIndex = i++;
+            return oldIndex % 2 ? data[oldIndex] : static_cast<float>(oldIndex);
+        });
+
+        const auto referenceTensor =
+            TosaTensor("out1", tosa_datatype_fp64_t, shape, reinterpret_cast<uint8_t*>(data.data()));
+        const auto implementationTensor =
+            TosaTensor("out1", tosa_datatype_fp32_t, shape, reinterpret_cast<uint8_t*>(otherData.data()));
+        REQUIRE_FALSE(
+            tvf_verify_data(referenceTensor.cTensor(), nullptr, implementationTensor.cTensor(), json_cfg.c_str()));
+    }
+}
+
+TEST_SUITE_END();    // verify