Main Conformance: Re-adjust TANH compliance check

Add lower bound to ABS ERROR checks to allow for cancellation of
small values in error bounds checking.
Re-adjust the error bounds multiplier to match the specification.
Fix up naming of verify library info structs.

Signed-off-by: Jeremy Johnson <jeremy.johnson@arm.com>
Change-Id: I3e178c3d7d59fef9c3696178646b23ed2a3ffc61

9 files changed, 77 insertions, 25 deletions

diff --git a/reference_model/src/ops/activation_funcs.cc b/reference_model/src/ops/activation_funcs.cc
index 787055c..c8fdc74 100644
--- a/reference_model/src/ops/activation_funcs.cc
+++ b/reference_model/src/ops/activation_funcs.cc
@@ -1,5 +1,5 @@
 
-// Copyright (c) 2020-2023, ARM Limited.
+// Copyright (c) 2020-2024, ARM Limited.
 //
 //    Licensed under the Apache License, Version 2.0 (the "License");
 //    you may not use this file except in compliance with the License.
@@ -123,8 +123,8 @@ int OpTanh<Rank, Dtype>::register_fcn()
         case TOSA_REF_TYPE_FP64:
             if (g_func_config.abs_mode)
             {
-                // ABS_ERROR bounds return 8*(1+abs(a))
-                this->fcn = [](InEigenType a) -> OutEigenType { return 8.0 * (1.0 + (a > (InEigenType)0 ? a : (-a))); };
+                // ABS_ERROR bounds return 4*(1+abs(a))
+                this->fcn = [](InEigenType a) -> OutEigenType { return 4.0 * (1.0 + (a > (InEigenType)0 ? a : (-a))); };
             }
             else
             {
diff --git a/reference_model/src/verify/verifiers.h b/reference_model/src/verify/verifiers.h
index f2590cb..152cd6a 100644
--- a/reference_model/src/verify/verifiers.h
+++ b/reference_model/src/verify/verifiers.h
@@ -1,5 +1,5 @@
 
-// Copyright (c) 2023, ARM Limited.
+// Copyright (c) 2023-2024, ARM Limited.
 //
 //    Licensed under the Apache License, Version 2.0 (the "License");
 //    you may not use this file except in compliance with the License.
@@ -55,19 +55,20 @@ bool verifyReduceProduct(const CTensor* referenceTensor, const CTensor* implemen
 ///
 /// \param referenceTensor    Reference tensor
 /// \param implementationTensor    Implementation resulting tensor
-/// \param ulp    The ULP tolerence for the comparison of the two tensors
+/// \param ulpInfo    The ULP tolerence info for the comparison of the two tensors
 ///
 /// \return True if compliant else false
-bool verifyULP(const CTensor* referenceTensor, const CTensor* implementationTensor, const UlpInfo& ulpInfo);
+bool verifyULP(const CTensor* referenceTensor, const CTensor* implementationTensor, const UlpVerifyInfo& ulpInfo);
 
 /// \brief Perform abs-error based verification
 ///
 /// \param ref    Reference tensor
 /// \param refBnd Reference bounds tensor (according to op)
 /// \param imp    Implementation resulting tensor
+/// \param aeInfo Abs-error verification meta-data
 ///
 /// \return True if compliant else false
-bool verifyAbsError(const CTensor* ref, const CTensor* refBnd, const CTensor* imp);
+bool verifyAbsError(const CTensor* ref, const CTensor* refBnd, const CTensor* imp, const AbsErrorVerifyInfo& aeInfo);
 
 };    // namespace TosaReference
 
diff --git a/reference_model/src/verify/verify_abs_error.cc b/reference_model/src/verify/verify_abs_error.cc
index 5aaa0ad..25ecae4 100644
--- a/reference_model/src/verify/verify_abs_error.cc
+++ b/reference_model/src/verify/verify_abs_error.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2023, ARM Limited.
+// Copyright (c) 2023-2024, ARM Limited.
 //
 //    Licensed under the Apache License, Version 2.0 (the "License");
 //    you may not use this file except in compliance with the License.
@@ -27,14 +27,23 @@ namespace TosaReference
 namespace
 {
 template <typename OutDtype>
-bool validateData(const double* ref, const double* bnd, const OutDtype* imp, const std::vector<int32_t>& shape)
+bool validateData(const double* ref,
+                  const double* bnd,
+                  const OutDtype* imp,
+                  const std::vector<int32_t>& shape,
+                  const AbsErrorVerifyInfo& cfg)
 {
     const size_t T = static_cast<size_t>(numElements(shape));
     TOSA_REF_REQUIRE(T > 0, "[AE] Invalid shape for reference tensor");
 
     for (size_t i = 0; i < T; ++i)
     {
-        double errBound = std::abs(ref[i]) * exp2(-AccPrecision<OutDtype>::normal_frac) * bnd[i];
+        double valBound = std::abs(ref[i]) * bnd[i];
+        if (cfg.lowerBound > 0)
+        {
+            valBound = std::max(cfg.lowerBound, valBound);
+        }
+        double errBound = exp2(-AccPrecision<OutDtype>::normal_frac) * valBound;
         bool valid      = tosaCheckFloatBound(imp[i], ref[i], errBound);
         if (!valid)
         {
@@ -46,7 +55,7 @@ bool validateData(const double* ref, const double* bnd, const OutDtype* imp, con
     return true;
 }
 }    // namespace
-bool verifyAbsError(const CTensor* ref, const CTensor* refBnd, const CTensor* imp)
+bool verifyAbsError(const CTensor* ref, const CTensor* refBnd, const CTensor* imp, const AbsErrorVerifyInfo& aeInfo)
 {
     // Validate that tensors are provided
     TOSA_REF_REQUIRE(ref != nullptr, "[AE] Reference tensor is missing");
@@ -64,12 +73,12 @@ bool verifyAbsError(const CTensor* ref, const CTensor* refBnd, const CTensor* im
         case tosa_datatype_fp32_t: {
             const auto* impData = reinterpret_cast<const float*>(imp->data);
             TOSA_REF_REQUIRE(impData != nullptr, "[AE] Missing data for implementation");
-            return validateData(refData, refBndData, impData, refShape);
+            return validateData(refData, refBndData, impData, refShape, aeInfo);
         }
         case tosa_datatype_fp16_t: {
             const auto* impData = reinterpret_cast<const half_float::half*>(imp->data);
             TOSA_REF_REQUIRE(impData != nullptr, "[AE] Missing data for implementation");
-            return validateData(refData, refBndData, impData, refShape);
+            return validateData(refData, refBndData, impData, refShape, aeInfo);
         }
         default:
             WARNING("[Verifier][AE] Data-type not supported.");
diff --git a/reference_model/src/verify/verify_entry.cc b/reference_model/src/verify/verify_entry.cc
index d0b31c6..2b318d1 100644
--- a/reference_model/src/verify/verify_entry.cc
+++ b/reference_model/src/verify/verify_entry.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2023, ARM Limited.
+// Copyright (c) 2023-2024, ARM Limited.
 //
 //    Licensed under the Apache License, Version 2.0 (the "License");
 //    you may not use this file except in compliance with the License.
@@ -41,7 +41,7 @@ bool verify(const CTensor* ref, const CTensor* refBnd, const CTensor* imp, const
             return verifyULP(ref, imp, cfg.ulpInfo);
         }
         case VerifyMode::AbsError: {
-            return verifyAbsError(ref, refBnd, imp);
+            return verifyAbsError(ref, refBnd, imp, cfg.absErrorInfo);
         }
         default: {
             WARNING("[Verifier] Unsupported verification mode.");
diff --git a/reference_model/src/verify/verify_ulp.cc b/reference_model/src/verify/verify_ulp.cc
index 1b38fe6..13bf0a9 100644
--- a/reference_model/src/verify/verify_ulp.cc
+++ b/reference_model/src/verify/verify_ulp.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2023, ARM Limited.
+// Copyright (c) 2023-2024, ARM Limited.
 //
 //    Licensed under the Apache License, Version 2.0 (the "License");
 //    you may not use this file except in compliance with the License.
@@ -48,7 +48,7 @@ bool tosaCheckULP(OutType testValue, double referenceValue, double ulpNum)
 }
 }    // namespace
 
-bool verifyULP(const CTensor* referenceTensor, const CTensor* implementationTensor, const UlpInfo& ulpInfo)
+bool verifyULP(const CTensor* referenceTensor, const CTensor* implementationTensor, const UlpVerifyInfo& ulpInfo)
 {
     // Validate that tensors are provided
     TOSA_REF_REQUIRE(referenceTensor != nullptr, "[ULP] Reference tensor is missing");
diff --git a/reference_model/src/verify/verify_utils.cc b/reference_model/src/verify/verify_utils.cc
index 3bdc99f..5ce646c 100644
--- a/reference_model/src/verify/verify_utils.cc
+++ b/reference_model/src/verify/verify_utils.cc
@@ -1,5 +1,5 @@
 
-// Copyright (c) 2023, ARM Limited.
+// Copyright (c) 2023-2024, ARM Limited.
 //
 //    Licensed under the Apache License, Version 2.0 (the "License");
 //    you may not use this file except in compliance with the License.
@@ -53,7 +53,7 @@ NLOHMANN_JSON_SERIALIZE_ENUM(VerifyMode,
                                  { VerifyMode::AbsError, "ABS_ERROR" },
                              })
 
-void from_json(const nlohmann::json& j, UlpInfo& ulpInfo)
+void from_json(const nlohmann::json& j, UlpVerifyInfo& ulpInfo)
 {
     j.at("ulp").get_to(ulpInfo.ulp);
 }
@@ -70,6 +70,14 @@ void from_json(const nlohmann::json& j, ReduceProductVerifyInfo& reduceProduceIn
     j.at("n").get_to(reduceProduceInfo.n);
 }
 
+void from_json(const nlohmann::json& j, AbsErrorVerifyInfo& absErrorInfo)
+{
+    if (j.contains("lower_bound"))
+    {
+        j.at("lower_bound").get_to(absErrorInfo.lowerBound);
+    }
+}
+
 void from_json(const nlohmann::json& j, VerifyConfig& cfg)
 {
     j.at("mode").get_to(cfg.mode);
@@ -86,6 +94,12 @@ void from_json(const nlohmann::json& j, VerifyConfig& cfg)
     {
         j.at("reduce_product_info").get_to(cfg.reduceProductInfo);
     }
+    // Set up defaults for optional AbsErrorVerifyInfo
+    cfg.absErrorInfo.lowerBound = 0;
+    if (j.contains("abs_error_info"))
+    {
+        j.at("abs_error_info").get_to(cfg.absErrorInfo);
+    }
 }
 
 std::optional<VerifyConfig> parseVerifyConfig(const char* tensorName, const char* json)
diff --git a/reference_model/src/verify/verify_utils.h b/reference_model/src/verify/verify_utils.h
index 45daeac..0fc68fb 100644
--- a/reference_model/src/verify/verify_utils.h
+++ b/reference_model/src/verify/verify_utils.h
@@ -1,5 +1,5 @@
 
-// Copyright (c) 2023, ARM Limited.
+// Copyright (c) 2023-2024, ARM Limited.
 //
 //    Licensed under the Apache License, Version 2.0 (the "License");
 //    you may not use this file except in compliance with the License.
@@ -50,9 +50,9 @@ enum class VerifyMode
 };
 
 /// \brief ULP verification meta-data
-struct UlpInfo
+struct UlpVerifyInfo
 {
-    UlpInfo() = default;
+    UlpVerifyInfo() = default;
 
     double ulp;
 };
@@ -75,6 +75,14 @@ struct ReduceProductVerifyInfo
     int64_t n;
 };
 
+/// \brief abs-error verification meta-data
+struct AbsErrorVerifyInfo
+{
+    AbsErrorVerifyInfo() = default;
+
+    double lowerBound;
+};
+
 /// \brief Verification meta-data
 struct VerifyConfig
 {
@@ -82,9 +90,10 @@ struct VerifyConfig
 
     VerifyMode mode;
     DType dataType;
-    UlpInfo ulpInfo;
+    UlpVerifyInfo ulpInfo;
     DotProductVerifyInfo dotProductInfo;
     ReduceProductVerifyInfo reduceProductInfo;
+    AbsErrorVerifyInfo absErrorInfo;
 };
 
 /// \brief Parse the verification config for a tensor when given in JSON form
diff --git a/scripts/schemavalidation/compliance-config.schema.json b/scripts/schemavalidation/compliance-config.schema.json
index e78d385..dd62404 100644
--- a/scripts/schemavalidation/compliance-config.schema.json
+++ b/scripts/schemavalidation/compliance-config.schema.json
@@ -1,5 +1,5 @@
  {
-    "$comment": "Copyright (c) 2023, ARM Limited.",
+    "$comment": "Copyright (c) 2023-2024, ARM Limited.",
     "$comment": "SPDX-License-Identifier: Apache-2.0",
     "$id": "compliance-config.schema.json",
     "$schema": "https://json-schema.org/draft/2020-12/schema",
@@ -61,6 +61,18 @@
                                 "s",
                                 "ks"
                             ]
+                        },
+                        "abs_error_info": {
+                            "description": "info required for the ABS_ERROR mode",
+                            "type": "object",
+                            "properties":
+                            {
+                                "lower_bound": {
+                                    "description": "lower bound multiplier for error bounds",
+                                    "type": "number"
+                                }
+                            },
+                            "additionalProperties": false
                         }
                     },
                     "additionalProperties": false,
diff --git a/verif/generator/tosa_test_gen.py b/verif/generator/tosa_test_gen.py
index 2290c54..5129e24 100644
--- a/verif/generator/tosa_test_gen.py
+++ b/verif/generator/tosa_test_gen.py
@@ -1,4 +1,4 @@
-# Copyright (c) 2020-2023, ARM Limited.
+# Copyright (c) 2020-2024, ARM Limited.
 # SPDX-License-Identifier: Apache-2.0
 import json
 import os
@@ -349,6 +349,10 @@ class TosaTestGen:
             mode = gtu.ComplianceMode.REDUCE_PRODUCT
         elif op["op"] in (Op.EXP, Op.POW, Op.TANH, Op.SIGMOID):
             mode = gtu.ComplianceMode.ABS_ERROR
+            if "compliance" in op and "abs_error_lower_bound" in op["compliance"]:
+                compliance_tens["abs_error_info"] = {
+                    "lower_bound": op["compliance"]["abs_error_lower_bound"]
+                }
         else:
             mode = gtu.ComplianceMode.EXACT
         compliance_tens["mode"] = gtu.ComplianceMode(mode).name
@@ -3262,6 +3266,9 @@ class TosaTestGen:
             "data_gen": {
                 "fp": (gtu.DataGenType.PSEUDO_RANDOM,),
             },
+            "compliance": {
+                "abs_error_lower_bound": 0.5,
+            },
         },
         "erf": {
             "op": Op.ERF,