From 0c96df128596b69b729b15357b59c76a12bcf76b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pawe=C5=82=20Bylica?= <chfast@gmail.com>
Date: Thu, 13 Aug 2020 11:18:10 +0200
Subject: [PATCH] test: Add tests for ceil, floor, trunc

---
 .../unittests/execute_floating_point_test.cpp | 76 +++++++++++++++++++
 1 file changed, 76 insertions(+)

diff --git a/test/unittests/execute_floating_point_test.cpp b/test/unittests/execute_floating_point_test.cpp
index 9d6a1a813c..229c771213 100644
--- a/test/unittests/execute_floating_point_test.cpp
+++ b/test/unittests/execute_floating_point_test.cpp
@@ -155,6 +155,32 @@ class execute_floating_point_types : public testing::Test
         FP<T>::nan(1),
     };
 
+    // The "int only" is the range of the floating-point type of only consecutive integer values.
+    // (Integer shift is used instead of std::pow() because of the clang compiler bug).
+    static constexpr auto int_only_begin = T{uint64_t{1} << (L::digits - 1)};
+    static constexpr auto int_only_end = T{uint64_t{1} << L::digits};
+
+    // The list of rounding test cases as pairs (input, expected_trunc) with only positive inputs.
+    inline static const std::pair<T, T> positive_trunc_tests[] = {
+        {0, 0},
+        {L::denorm_min(), 0},
+        {L::min(), 0},
+        {std::nextafter(T{1}, T{0}), T{0}},
+        {T{1}, T{1}},
+        {std::nextafter(T{1}, T{2}), T{1}},
+        {std::nextafter(T{2}, T{1}), T{1}},
+        {T{2}, T{2}},
+        {int_only_begin - T{1}, int_only_begin - T{1}},
+        {int_only_begin - T{0.5}, int_only_begin - T{1}},
+        {int_only_begin, int_only_begin},
+        {int_only_begin + T{1}, int_only_begin + T{1}},
+        {int_only_end - T{1}, int_only_end - T{1}},
+        {int_only_end, int_only_end},
+        {int_only_end + T{2}, int_only_end + T{2}},
+        {L::max(), L::max()},
+        {L::infinity(), L::infinity()},
+    };
+
     /// Creates a wasm module with a single function for the given instructions opcode.
     /// The opcode is converted to match the type, e.g. f32_add -> f64_add.
     static bytes get_numeric_instruction_code(
@@ -244,6 +270,9 @@ TYPED_TEST(execute_floating_point_types, unop_nan_propagation)
     // The list of instructions to be tested.
     // Only f32 variants, but f64 variants are going to be covered as well.
     constexpr Instr opcodes[] = {
+        Instr::f32_ceil,
+        Instr::f32_floor,
+        Instr::f32_trunc,
         Instr::f32_sqrt,
     };
 
@@ -438,6 +467,53 @@ TYPED_TEST(execute_floating_point_types, neg)
     }
 }
 
+TYPED_TEST(execute_floating_point_types, ceil)
+{
+    auto instance = instantiate(parse(this->get_unop_code(Instr::f32_ceil)));
+    const auto exec = [&](auto arg) { return execute(*instance, 0, {arg}); };
+
+    for (const auto& [arg, expected_trunc] : this->positive_trunc_tests)
+    {
+        // For positive values, the ceil() is trunc() + 1, unless the input is already an integer.
+        const auto expected_pos =
+            (arg == expected_trunc) ? expected_trunc : expected_trunc + TypeParam{1};
+        EXPECT_THAT(exec(arg), Result(expected_pos)) << arg << ": " << expected_pos;
+
+        // For negative values, the ceil() is trunc().
+        EXPECT_THAT(exec(-arg), Result(-expected_trunc)) << -arg << ": " << -expected_trunc;
+    }
+}
+
+TYPED_TEST(execute_floating_point_types, floor)
+{
+    auto instance = instantiate(parse(this->get_unop_code(Instr::f32_floor)));
+    const auto exec = [&](auto arg) { return execute(*instance, 0, {arg}); };
+
+    for (const auto& [arg, expected_trunc] : this->positive_trunc_tests)
+    {
+        // For positive values, the floor() is trunc().
+        EXPECT_THAT(exec(arg), Result(expected_trunc)) << arg << ": " << expected_trunc;
+
+        // For negative values, the floor() is trunc() - 1, unless the input is already an integer.
+        const auto expected_neg =
+            (arg == expected_trunc) ? -expected_trunc : -expected_trunc - TypeParam{1};
+        EXPECT_THAT(exec(-arg), Result(expected_neg)) << -arg << ": " << expected_neg;
+    }
+}
+
+TYPED_TEST(execute_floating_point_types, trunc)
+{
+    auto instance = instantiate(parse(this->get_unop_code(Instr::f32_trunc)));
+    const auto exec = [&](auto arg) { return execute(*instance, 0, {arg}); };
+
+    for (const auto& [arg, expected] : this->positive_trunc_tests)
+    {
+        EXPECT_THAT(exec(arg), Result(expected)) << arg << ": " << expected;
+        EXPECT_THAT(exec(-arg), Result(-expected)) << -arg << ": " << -expected;
+    }
+}
+
+
 TYPED_TEST(execute_floating_point_types, sqrt)
 {
     using FP = FP<TypeParam>;