[dynarmic] Remove last FPT LUT table, removing around 30kb worth of unused functions (#3718)

Lets do the quick math
There was 1 LUT for every fsize() instancing

Now... the number of functions on each lut was (fsize + 1), multiplied by 5 (number of rounding modes)

8 = 9 * 5 = 45
16 = 17 * 5 = 85
32 = 33 * 5 = 165
64 = 65 * 5 = 325

this is just pure insanity - look at what fucking nm reported:

```
0000000003dc39b8 0000000000000008 V guard variable for void Dynarmic::Backend::X64::EmitFPVectorToFixed<16ul, false>(Dynarmic::Backend::X64::BlockOfCode&, Dynarmic::Backend::X64::EmitContext&, Dynarmic::IR::Inst*)::lut
0000000003dc3a18 0000000000000008 V guard variable for void Dynarmic::Backend::X64::EmitFPVectorToFixed<16ul, true>(Dynarmic::Backend::X64::BlockOfCode&, Dynarmic::Backend::X64::EmitContext&, Dynarmic::IR::Inst*)::lut
0000000003dc39d8 0000000000000008 V guard variable for void Dynarmic::Backend::X64::EmitFPVectorToFixed<32ul, false>(Dynarmic::Backend::X64::BlockOfCode&, Dynarmic::Backend::X64::EmitContext&, Dynarmic::IR::Inst*)::lut
0000000003dc3a38 0000000000000008 V guard variable for void Dynarmic::Backend::X64::EmitFPVectorToFixed<32ul, true>(Dynarmic::Backend::X64::BlockOfCode&, Dynarmic::Backend::X64::EmitContext&, Dynarmic::IR::Inst*)::lut
0000000003dc39f8 0000000000000008 V guard variable for void Dynarmic::Backend::X64::EmitFPVectorToFixed<64ul, false>(Dynarmic::Backend::X64::BlockOfCode&, Dynarmic::Backend::X64::EmitContext&, Dynarmic::IR::Inst*)::lut
0000000003dc3a58 0000000000000008 V guard variable for void Dynarmic::Backend::X64::EmitFPVectorToFixed<64ul, true>(Dynarmic::Backend::X64::BlockOfCode&, Dynarmic::Backend::X64::EmitContext&, Dynarmic::IR::Inst*)::lut
```

"ah its not bad" - OH MATE ITS JUST THE GUARD VARIABLES - i attached a file with just the functions generated for each case...

now with this PR only 6 * 6 functions are made (still not ideal, but way better), 36 is way better than 1156 FUCKING FUNCTIONS

Signed-off-by: lizzie <lizzie@eden-emu.dev>

Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/3718
Reviewed-by: DraVee <chimera@dravee.dev>
Reviewed-by: Maufeat <sahyno1996@gmail.com>
Co-authored-by: lizzie <lizzie@eden-emu.dev>
Co-committed-by: lizzie <lizzie@eden-emu.dev>

src/dynarmic/src/dynarmic/CMakeLists.txt

@@ -53,7 +53,6 @@ add_library(dynarmic STATIC
     common/fp/util.h
     common/llvm_disassemble.cpp
     common/llvm_disassemble.h
-    common/lut_from_list.h
     common/math_util.cpp
     common/math_util.h
     common/safe_ops.h

src/dynarmic/src/dynarmic/backend/arm64/emit_arm64_vector_floating_point.cpp

@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
 // SPDX-License-Identifier: GPL-3.0-or-later
 
 /* This file is part of the dynarmic project.
@@ -31,7 +31,6 @@
 #include "dynarmic/common/fp/info.h"
 #include "dynarmic/common/fp/op.h"
 #include "dynarmic/common/fp/rounding_mode.h"
-#include "dynarmic/common/lut_from_list.h"
 #include "dynarmic/ir/basic_block.h"
 #include "dynarmic/ir/microinstruction.h"
 #include "dynarmic/ir/opcodes.h"

src/dynarmic/src/dynarmic/backend/x64/emit_x64_floating_point.cpp

@@ -31,7 +31,6 @@
 #include "dynarmic/common/fp/info.h"
 #include "dynarmic/common/fp/op.h"
 #include "dynarmic/common/fp/rounding_mode.h"
-#include "dynarmic/common/lut_from_list.h"
 #include "dynarmic/interface/optimization_flags.h"
 #include "dynarmic/ir/basic_block.h"
 #include "dynarmic/ir/microinstruction.h"

src/dynarmic/src/dynarmic/backend/x64/emit_x64_vector_floating_point.cpp

@@ -31,7 +31,6 @@
 #include "dynarmic/common/fp/info.h"
 #include "dynarmic/common/fp/op.h"
 #include "dynarmic/common/fp/util.h"
-#include "dynarmic/common/lut_from_list.h"
 #include "dynarmic/interface/optimization_flags.h"
 #include "dynarmic/ir/basic_block.h"
 #include "dynarmic/ir/microinstruction.h"
@@ -2127,28 +2126,42 @@ void EmitFPVectorToFixed(BlockOfCode& code, EmitContext& ctx, IR::Inst* inst) {
         }
     }
 
-    using fbits_list = mp::lift_sequence<std::make_index_sequence<fsize + 1>>;
-    using rounding_list = mp::list<
-        mp::lift_value<FP::RoundingMode::ToNearest_TieEven>,
-        mp::lift_value<FP::RoundingMode::TowardsPlusInfinity>,
-        mp::lift_value<FP::RoundingMode::TowardsMinusInfinity>,
-        mp::lift_value<FP::RoundingMode::TowardsZero>,
-        mp::lift_value<FP::RoundingMode::ToNearest_TieAwayFromZero>>;
-
-    static const auto lut = Common::GenerateLookupTableFromList([]<typename I>(I) {
-        using FPT = mcl::unsigned_integer_of_size<fsize>;  // WORKAROUND: For issue 678 on MSVC
-        return std::pair{
-            mp::lower_to_tuple_v<I>,
-            Common::FptrCast([](VectorArray<FPT>& output, const VectorArray<FPT>& input, FP::FPCR fpcr, FP::FPSR& fpsr) {
-                constexpr size_t fbits = mp::get<0, I>::value;
-                constexpr FP::RoundingMode rounding_mode = mp::get<1, I>::value;
+    using FPT = mcl::unsigned_integer_of_size<fsize>; // WORKAROUND: For issue 678 on MSVC
+    auto const func = [rounding]() -> void(*)(VectorArray<FPT>& output, const VectorArray<FPT>& input, FP::FPCR fpcr, FP::FPSR& fpsr) {
+        switch (rounding) {
+        case FP::RoundingMode::ToNearest_TieEven:
+            return [](VectorArray<FPT>& output, const VectorArray<FPT>& input, FP::FPCR fpcr, FP::FPSR& fpsr) {
                 for (size_t i = 0; i < output.size(); ++i)
-                    output[i] = FPT(FP::FPToFixed<FPT>(fsize, input[i], fbits, unsigned_, fpcr, rounding_mode, fpsr));
-            })
-        };
-    }, mp::cartesian_product<fbits_list, rounding_list>{});
-
-    EmitTwoOpFallback<3>(code, ctx, inst, lut.at(std::make_tuple(fbits, rounding)));
+                    output[i] = FPT(FP::FPToFixed<FPT>(fsize, input[i], fsize, unsigned_, fpcr, FP::RoundingMode::ToNearest_TieEven, fpsr));
+            };
+        case FP::RoundingMode::TowardsPlusInfinity:
+            return [](VectorArray<FPT>& output, const VectorArray<FPT>& input, FP::FPCR fpcr, FP::FPSR& fpsr) {
+                for (size_t i = 0; i < output.size(); ++i)
+                    output[i] = FPT(FP::FPToFixed<FPT>(fsize, input[i], fsize, unsigned_, fpcr, FP::RoundingMode::TowardsPlusInfinity, fpsr));
+            };
+        case FP::RoundingMode::TowardsMinusInfinity:
+            return [](VectorArray<FPT>& output, const VectorArray<FPT>& input, FP::FPCR fpcr, FP::FPSR& fpsr) {
+                for (size_t i = 0; i < output.size(); ++i)
+                    output[i] = FPT(FP::FPToFixed<FPT>(fsize, input[i], fsize, unsigned_, fpcr, FP::RoundingMode::TowardsMinusInfinity, fpsr));
+            };
+        case FP::RoundingMode::TowardsZero:
+            return [](VectorArray<FPT>& output, const VectorArray<FPT>& input, FP::FPCR fpcr, FP::FPSR& fpsr) {
+                for (size_t i = 0; i < output.size(); ++i)
+                    output[i] = FPT(FP::FPToFixed<FPT>(fsize, input[i], fsize, unsigned_, fpcr, FP::RoundingMode::TowardsZero, fpsr));
+            };
+        case FP::RoundingMode::ToNearest_TieAwayFromZero:
+            return [](VectorArray<FPT>& output, const VectorArray<FPT>& input, FP::FPCR fpcr, FP::FPSR& fpsr) {
+                for (size_t i = 0; i < output.size(); ++i)
+                    output[i] = FPT(FP::FPToFixed<FPT>(fsize, input[i], fsize, unsigned_, fpcr, FP::RoundingMode::ToNearest_TieAwayFromZero, fpsr));
+            };
+        case FP::RoundingMode::ToOdd:
+            return [](VectorArray<FPT>& output, const VectorArray<FPT>& input, FP::FPCR fpcr, FP::FPSR& fpsr) {
+                for (size_t i = 0; i < output.size(); ++i)
+                    output[i] = FPT(FP::FPToFixed<FPT>(fsize, input[i], fsize, unsigned_, fpcr, FP::RoundingMode::ToOdd, fpsr));
+            };
+        }
+    }();
+    EmitTwoOpFallback<3>(code, ctx, inst, func);
 }
 
 void EmitX64::EmitFPVectorToSignedFixed16(EmitContext& ctx, IR::Inst* inst) {

src/dynarmic/src/dynarmic/common/lut_from_list.h

@@ -1,55 +0,0 @@
-// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
-// SPDX-License-Identifier: GPL-3.0-or-later
-
-/* This file is part of the dynarmic project.
- * Copyright (c) 2018 MerryMage
- * SPDX-License-Identifier: 0BSD
- */
-
-#pragma once
-
-#include <initializer_list>
-#include <map>
-#include <type_traits>
-
-#include <mcl/mp/metafunction/apply.hpp>
-#include <mcl/mp/typelist/list.hpp>
-#include <mcl/type_traits/is_instance_of_template.hpp>
-
-#ifdef _MSC_VER
-#    include <mcl/mp/typelist/head.hpp>
-#endif
-
-namespace Dynarmic::Common {
-
-// prevents this function from printing 56,000 character warning messages
-#ifdef __GNUC__
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wno-stack-usage"
-#endif
-#ifdef __clang__
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wno-stack-usage"
-#endif
-
-template<typename Function, typename... Values>
-inline auto GenerateLookupTableFromList(Function f, mcl::mp::list<Values...>) {
-#ifdef _MSC_VER
-    using PairT = std::invoke_result_t<Function, mcl::mp::head<mcl::mp::list<Values...>>>;
-#else
-    using PairT = std::common_type_t<std::invoke_result_t<Function, Values>...>;
-#endif
-    using MapT = mcl::mp::apply<std::map, PairT>;
-    static_assert(mcl::is_instance_of_template_v<std::pair, PairT>);
-    const std::initializer_list<PairT> pair_array{f(Values{})...};
-    return MapT(pair_array.begin(), pair_array.end());
-}
-
-#ifdef __GNUC__
-#pragma GCC diagnostic pop
-#endif
-#ifdef __clang__
-#pragma clang diagnostic pop
-#endif
-
-}  // namespace Dynarmic::Common