[libc-commits] [libc] [libc][math] Add Generic Comparison Operations for floating point types (PR #144983)

[via libc-commits]

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+//===-- Unittests for Comparison Operations for FPBits class --------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/__support/FPUtil/ComparisonOperations.h"
+#include "src/__support/FPUtil/FPBits.h"
+#include "src/__support/macros/properties/types.h"
+#include "src/__support/sign.h"
+#include "test/UnitTest/FEnvSafeTest.h"
+#include "test/UnitTest/FPMatcher.h"
+#include "test/UnitTest/Test.h"
+
+using LIBC_NAMESPACE::fputil::equals;
+using LIBC_NAMESPACE::fputil::greater_than;
+using LIBC_NAMESPACE::fputil::greater_than_or_equals;
+using LIBC_NAMESPACE::fputil::less_than;
+using LIBC_NAMESPACE::fputil::less_than_or_equals;
+
+template <typename T>
+class ComparisonOperationsTest : public LIBC_NAMESPACE::testing::FEnvSafeTest {
+  DECLARE_SPECIAL_CONSTANTS(T)
+
+  static constexpr T normal1 = T(3.14);
+  static constexpr T normal2 = T(2.71);
+  static constexpr T small = T(0.1);
+  static constexpr T neg_small = T(-0.1);
+  static constexpr T large = T(10000.0);
+  static constexpr T neg_large = T(-10000.0);
+
+public:
+  void test_equals() {
+    EXPECT_TRUE(equals(neg_zero, neg_zero));
+    EXPECT_TRUE(equals(zero, neg_zero));
+    EXPECT_TRUE(equals(neg_zero, zero));
+
+    EXPECT_TRUE(equals(inf, inf));
+    EXPECT_TRUE(equals(neg_inf, neg_inf));
+    EXPECT_FALSE(equals(inf, neg_inf));
+    EXPECT_FALSE(equals(neg_inf, inf));
+
+    EXPECT_TRUE(equals(normal1, normal1));
+    EXPECT_TRUE(equals(normal2, normal2));
+    EXPECT_FALSE(equals(normal1, normal2));
+    EXPECT_FALSE(equals(normal1, -normal1));
+
+    LIBC_NAMESPACE::fputil::clear_except(FE_ALL_EXCEPT);
+    auto test_qnan = [&](T x, T y) {
+      EXPECT_FALSE(equals(x, y));
+      // NOTE: equals and not equals operations should raise FE_INVALID for
+      // quiet NaN operands
+      EXPECT_FP_EXCEPTION(0);
+    };
+
+    test_qnan(aNaN, aNaN);
+    test_qnan(aNaN, neg_aNaN);
+    test_qnan(aNaN, zero);
+    test_qnan(aNaN, inf);
+    test_qnan(aNaN, normal1);
+
+    test_qnan(neg_aNaN, neg_aNaN);
+    test_qnan(neg_aNaN, aNaN);
+    test_qnan(neg_aNaN, zero);
+    test_qnan(neg_aNaN, inf);
+    test_qnan(neg_aNaN, normal1);
+
+    auto test_snan = [&](T x, T y) {
+      LIBC_NAMESPACE::fputil::clear_except(FE_ALL_EXCEPT);
+      EXPECT_FALSE(equals(x, y));
+      EXPECT_FP_EXCEPTION(FE_INVALID);
+    };
+
+    test_snan(sNaN, sNaN);
+    test_snan(sNaN, neg_sNaN);
+    test_snan(sNaN, aNaN);
+    test_snan(sNaN, neg_aNaN);
+    test_snan(sNaN, zero);
+    test_snan(sNaN, neg_zero);
+    test_snan(sNaN, inf);
+    test_snan(sNaN, neg_inf);
+    test_snan(sNaN, normal1);
+
+    test_snan(neg_sNaN, neg_sNaN);
+    test_snan(neg_sNaN, sNaN);
+    test_snan(neg_sNaN, aNaN);
+    test_snan(neg_sNaN, neg_aNaN);
+    test_snan(neg_sNaN, zero);
+    test_snan(neg_sNaN, neg_zero);
+    test_snan(neg_sNaN, inf);
+    test_snan(neg_sNaN, neg_inf);
+    test_snan(neg_sNaN, normal1);
+  }
+
+  void test_less_than() {
+    EXPECT_TRUE(less_than(neg_small, small));
+    EXPECT_TRUE(less_than(small, large));
+
+    EXPECT_TRUE(less_than(neg_large, neg_small));
+    EXPECT_FALSE(less_than(large, small));
+    EXPECT_FALSE(less_than(small, neg_small));
+
+    EXPECT_FALSE(less_than(zero, neg_zero));
+    EXPECT_FALSE(less_than(neg_zero, zero));
+    EXPECT_FALSE(less_than(zero, zero));
+
+    EXPECT_TRUE(less_than(neg_small, zero));
+    EXPECT_TRUE(less_than(neg_zero, small));
+    EXPECT_FALSE(less_than(small, zero));
+
+    EXPECT_TRUE(less_than(neg_inf, inf));
+    EXPECT_TRUE(less_than(neg_inf, neg_small));
+    EXPECT_TRUE(less_than(small, inf));
+    EXPECT_FALSE(less_than(inf, small));
+
+    EXPECT_FALSE(less_than(small, small));
+    EXPECT_FALSE(less_than(neg_inf, neg_inf));
+
+    auto test_qnan = [&](T x, T y) {
+      LIBC_NAMESPACE::fputil::clear_except(FE_ALL_EXCEPT);
+      EXPECT_FALSE(less_than(x, y));
+      // NOTE: All signaling comparison operations other than equals and not
+      // equals should raise FE_INVALID when comparing with NaN
+      // see Note after table 5.1 in IEEE Std 754-2019
+      //    [...] The Signaling predicates in Table 5.1 signal the invalid
+      //    operation exception on quiet NaN operands to warn of potential
+      //    incorrect behavior of programs written assuming trichotomy.
+      EXPECT_FP_EXCEPTION(FE_INVALID);
+    };
+
+    test_qnan(aNaN, small);
+    test_qnan(small, aNaN);
+    test_qnan(aNaN, aNaN);
+    test_qnan(neg_aNaN, neg_small);
+    test_qnan(neg_small, neg_aNaN);
+    test_qnan(neg_aNaN, neg_aNaN);
+
+    auto test_snan = [&](T x, T y) {
+      LIBC_NAMESPACE::fputil::clear_except(FE_ALL_EXCEPT);
+      EXPECT_FALSE(less_than(x, y));
+      EXPECT_FP_EXCEPTION(FE_INVALID);
+    };
+
+    test_snan(sNaN, small);
+    test_snan(sNaN, neg_small);
+    test_snan(sNaN, zero);
+    test_snan(sNaN, inf);
+    test_snan(sNaN, aNaN);
+    test_snan(sNaN, sNaN);
+
+    test_snan(neg_sNaN, small);
+    test_snan(neg_sNaN, neg_small);
+    test_snan(neg_sNaN, zero);
+    test_snan(neg_sNaN, inf);
+    test_snan(neg_sNaN, aNaN);
+    test_snan(neg_sNaN, neg_sNaN);
+  }
+  void test_greater_than() {
----------------
overmighty wrote:

Nit: spacing/formatting.


```suggestion
  }

  void test_greater_than() {
```

https://github.com/llvm/llvm-project/pull/144983