From 52ed365158b9c785352579966d466b1cfd26534e Mon Sep 17 00:00:00 2001
From: MerryMage <MerryMage@users.noreply.github.com>
Date: Thu, 28 Jun 2018 21:46:16 +0100
Subject: [PATCH] tests/fp: Add FPRound tests

---
 tests/fp/unpacked_tests.cpp | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/tests/fp/unpacked_tests.cpp b/tests/fp/unpacked_tests.cpp
index 4c5a28b9..f17fc99c 100644
--- a/tests/fp/unpacked_tests.cpp
+++ b/tests/fp/unpacked_tests.cpp
@@ -7,6 +7,7 @@
 #include <catch.hpp>
 
 #include "common/fp/unpacked.h"
+#include "rand_int.h"
 
 using namespace Dynarmic;
 using namespace Dynarmic::FP;
@@ -21,6 +22,7 @@ TEST_CASE("FPUnpack Tests", "[fp]") {
         {0x7FC00001, {FPType::QNaN, false, {false, 0, 0}}, 0},
         {0xFFC00001, {FPType::QNaN, true, {true, 0, 0}}, 0},
         {0x00000001, {FPType::Nonzero, false, {false, -149, 1}}, 0}, // Smallest single precision denormal is 2^-149.
+        {0x3F7FFFFF, {FPType::Nonzero, false, {false, -24, 0xFFFFFF}}, 0}, // 1.0 - epsilon
     };
 
     const FPCR fpcr;
@@ -33,3 +35,37 @@ TEST_CASE("FPUnpack Tests", "[fp]") {
         REQUIRE(fpsr.Value() == expected_fpsr);
     }
 }
+
+TEST_CASE("FPRound Tests", "[fp]") {
+    const static std::vector<std::tuple<u32, std::tuple<FPType, bool, FPUnpacked<u64>>, u32>> test_cases {
+        {0x7F800000, {FPType::Infinity, false, {false, 1000000, 1}}, 0x14},
+        {0xFF800000, {FPType::Infinity, true, {true, 1000000, 1}}, 0x14},
+        {0x00000001, {FPType::Nonzero, false, {false, -149, 1}}, 0}, // Smallest single precision denormal is 2^-149.
+        {0x3F7FFFFF, {FPType::Nonzero, false, {false, -24, 0xFFFFFF}}, 0}, // 1.0 - epsilon
+        {0x3F800000, {FPType::Nonzero, false, {false, -28, 0xFFFFFFF}}, 0x10}, // rounds to 1.0
+    };
+
+    const FPCR fpcr;
+    for (const auto& [expected_output, input, expected_fpsr] : test_cases) {
+        FPSR fpsr;
+        const auto output = FPRound<u32>(std::get<2>(input), fpcr, fpsr);
+
+        INFO("Expected Output: " << std::hex << expected_output);
+        REQUIRE(output == expected_output);
+        REQUIRE(fpsr.Value() == expected_fpsr);
+    }
+}
+
+TEST_CASE("FPUnpack<->FPRound Round-trip Tests", "[fp]") {
+    const FPCR fpcr;
+    for (size_t count = 0; count < 100000; count++) {
+        FPSR fpsr;
+        const u32 input = RandInt(0, 1) == 0 ? RandInt<u32>(0x00000001, 0x7F800000) : RandInt<u32>(0x80000001, 0xFF800000);
+        const auto intermediate = std::get<2>(FPUnpack<u32>(input, fpcr, fpsr));
+        const u32 output = FPRound<u32>(intermediate, fpcr, fpsr);
+
+        INFO("Count: " << count);
+        INFO("Intermediate Values: " << std::hex << intermediate.sign << ';' << intermediate.exponent << ';' << intermediate.mantissa);
+        REQUIRE(input == output);
+    }
+}