arch-vega: Unit test for MXFP types

Add a unit test for the MXFP types (bf16, fp16, fp8, bf8). These types
are not currently operated on directly. Instead the are cast to float
values and then arithmetic is performed. As a result, the unit test
simply checks that when we convert a value from MXFP type to float and
back that the values of the MXFP type match. Exact values are used to
avoid discrepancies with rounding.

Can be run using scons build/VEGA_X86/unittests.opt .

Change-Id: I596e9368eb929d239dd2d917e3abd7927b15b71e

src/arch/amdgpu/common/dtype/SConscript

@@ -0,0 +1,32 @@
+# Copyright (c) 2024 Advanced Micro Devices, Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+# 1. Redistributions of source code must retain the above copyright notice,
+# this list of conditions and the following disclaimer.
+#
+# 2. Redistributions in binary form must reproduce the above copyright notice,
+# this list of conditions and the following disclaimer in the documentation
+# and/or other materials provided with the distribution.
+#
+# 3. Neither the name of the copyright holder nor the names of its
+# contributors may be used to endorse or promote products derived from this
+# software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+
+Import('*')
+
+GTest('mxfp.test', 'mxfp.test.cc')

src/arch/amdgpu/common/dtype/mxfp.test.cc

@@ -0,0 +1,104 @@
+/*
+ * Copyright (c) 2024 Advanced Micro Devices, Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its
+ * contributors may be used to endorse or promote products derived from this
+ * software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <gtest/gtest.h>
+
+#include "arch/amdgpu/common/dtype/mxfp_types.hh"
+
+template<typename T>
+bool test_raw_mxfp(T raw_mxfp, int bits)
+{
+    float tmp = float(raw_mxfp);
+    T from_float(tmp);
+
+    // Simply check that casting to float and back yields the same bit values.
+    // Exclude inf/NaN as those have multiple values in some MXFP types.
+    if (raw_mxfp.data != from_float.data &&
+        !std::isnan(tmp) && !std::isinf(tmp)) {
+        return false;
+    }
+
+    return true;
+}
+
+template<typename T>
+int test_type(int bits)
+{
+    T raw_mxfp;
+    int errors = 0;
+
+    int max_val = 1 << bits;
+    for (int val = 0; val < max_val; ++val) {
+        // Raw data is aligned to MSb in MXFP types. Shift into place.
+        raw_mxfp.data = val << (32 - bits);
+        if (!test_raw_mxfp(raw_mxfp, bits)) {
+            errors++;
+        }
+    }
+
+    return errors;
+}
+
+TEST(MxfpTest, MxBf16Test)
+{
+    using T = gem5::AMDGPU::mxbfloat16;
+
+    int errors = test_type<T>(T::size());
+
+    EXPECT_EQ(errors, 0);
+}
+
+TEST(MxfpTest, MxFp16Test)
+{
+    using T = gem5::AMDGPU::mxfloat16;
+
+    int errors = test_type<T>(T::size());
+
+    EXPECT_EQ(errors, 0);
+}
+
+TEST(MxfpTest, MxBf8Test)
+{
+    using T = gem5::AMDGPU::mxbfloat8;
+
+    int errors = test_type<T>(T::size());
+
+    EXPECT_EQ(errors, 0);
+}
+
+TEST(MxfpTest, MxFp8Test)
+{
+    using T = gem5::AMDGPU::mxfloat8;
+
+    int errors = test_type<T>(T::size());
+
+    EXPECT_EQ(errors, 0);
+}