Update cpp generator to handle inf from float (#1758)

Use std::numeric_limits::min/max() functions plus the appropriate value to encode -inf/inf 

src/cpp_generator.cpp

@@ -208,8 +208,24 @@ cpp_generator::function cpp_generator::generate_module(const module& m,
     f.set_name(name).set_types(m).set_body(
         m, [&](instruction_ref ins, const auto& names) -> std::string {
             if(ins->name() == "@literal")
-                return shape::cpp_type(ins->get_shape().type()) + "(" +
-                       ins->get_literal().to_string() + ")";
+            {
+                std::string string_literal;
+                ins->get_literal().visit([&](auto v) {
+                    assert(v.size() == 1);
+                    auto x = v.front();
+                    if(std::isinf(x))
+                    {
+                        string_literal = "__builtin_huge_val()";
+                        if(x < 0)
+                            string_literal = "-__builtin_huge_val()";
+                    }
+                    else if(std::isnan(x))
+                        string_literal = "__builtin_nan()";
+                    else
+                        string_literal = ins->get_literal().to_string();
+                });
+                return shape::cpp_type(ins->get_shape().type()) + "(" + string_literal + ")";
+            }
             auto s = g(ins, names);
             if(impl->fresult)
                 return impl->fresult(ins->get_shape()) + '(' + s + ')';

test/verify/test_literal_limits.cpp

+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2015-2023 Advanced Micro Devices, Inc. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "verify_program.hpp"
+#include <migraphx/program.hpp>
+#include <migraphx/make_op.hpp>
+#include <limits>
+
+template <migraphx::shape::type_t Q, typename T>
+struct test_literal_limits : verify_program<test_literal_limits<Q, T>>
+{
+    migraphx::program create_program() const
+    {
+        migraphx::program p;
+        auto* mm          = p.get_main_module();
+        auto input_s      = migraphx::shape(Q, {3, 1});
+        auto infinity_val = std::numeric_limits<T>::infinity();
+        std::vector<T> s_data{
+            infinity_val, static_cast<T>(-infinity_val), std::numeric_limits<T>::quiet_NaN()};
+
+        auto input_param = mm->add_parameter("test_input", input_s);
+        auto input       = mm->add_literal(migraphx::literal{input_s, s_data});
+        auto o1          = mm->add_instruction(migraphx::make_op("mul"), input, input_param);
+        mm->add_instruction(migraphx::make_op("isnan"), o1);
+        return p;
+    }
+};
+
+template struct test_literal_limits<migraphx::shape::float_type, float>;
+template struct test_literal_limits<migraphx::shape::double_type, double>;
+template struct test_literal_limits<migraphx::shape::half_type, migraphx::half>;
+template struct test_literal_limits<migraphx::shape::int32_type, int32_t>;
+template struct test_literal_limits<migraphx::shape::int8_type, int8_t>;