fp/op: Implement FPToFixed

tests/fp/FPToFixed.cpp

@@ -0,0 +1,38 @@
+/* This file is part of the dynarmic project.
+ * Copyright (c) 2018 MerryMage
+ * This software may be used and distributed according to the terms of the GNU
+ * General Public License version 2 or any later version.
+ */
+
+#include <tuple>
+#include <vector>
+
+#include <catch.hpp>
+
+#include "common/fp/fpsr.h"
+#include "common/fp/op.h"
+#include "rand_int.h"
+
+using namespace Dynarmic;
+using namespace Dynarmic::FP;
+
+TEST_CASE("FPToFixed", "[fp]") {
+    const std::vector<std::tuple<u32, size_t, u64, u32>> test_cases {
+        {0x447A0000, 64, 0x000003E8, 0x00},
+        {0xC47A0000, 32, 0xFFFFFC18, 0x00},
+        {0x4479E000, 64, 0x000003E8, 0x10},
+        {0x50800000, 32, 0x7FFFFFFF, 0x01},
+        {0xD0800000, 32, 0x80000000, 0x01},
+        {0xCF000000, 32, 0x80000000, 0x00},
+        {0x80002B94, 64, 0x00000000, 0x10},
+        {0x80636D24, 64, 0x00000000, 0x10},
+    };
+
+    const FPCR fpcr;
+    for (auto [input, ibits, expected_output, expected_fpsr] : test_cases) {
+        FPSR fpsr;
+        const u64 output = FPToFixed<u32>(ibits, input, 0, false, fpcr, RoundingMode::ToNearest_TieEven, fpsr);
+        REQUIRE(output == expected_output);
+        REQUIRE(fpsr.Value() == expected_fpsr);
+    }
+}