backend/rv64: Add a dummy code generation

src/dynarmic/CMakeLists.txt

@@ -410,6 +410,9 @@ if ("riscv" IN_LIST ARCHITECTURE)
             backend/riscv64/a32_interface.cpp
             backend/riscv64/a32_jitstate.cpp
             backend/riscv64/a32_jitstate.h
+            backend/riscv64/code_block.h
+            backend/riscv64/emit_riscv64.cpp
+            backend/riscv64/emit_riscv64.h
         )
     endif()
 

src/dynarmic/backend/riscv64/a32_address_space.cpp

@@ -5,6 +5,7 @@
 
 #include "dynarmic/backend/riscv64/a32_address_space.h"
 
+#include "dynarmic/backend/riscv64/emit_riscv64.h"
 #include "dynarmic/frontend/A32/a32_location_descriptor.h"
 #include "dynarmic/frontend/A32/translate/a32_translate.h"
 #include "dynarmic/ir/opt/passes.h"
@@ -12,7 +13,9 @@
 namespace Dynarmic::Backend::RV64 {
 
 A32AddressSpace::A32AddressSpace(const A32::UserConfig& conf)
-        : conf(conf) {
+        : conf(conf)
+        , cb(conf.code_cache_size)
+        , as(cb.ptr(), conf.code_cache_size) {
     EmitPrelude();
 }
 
@@ -47,17 +50,81 @@ void* A32AddressSpace::GetOrEmit(IR::LocationDescriptor descriptor) {
     }
 
     IR::Block ir_block = GenerateIR(descriptor);
-    void* block_entry = Emit(std::move(ir_block));
-    block_entries.insert_or_assign(descriptor.Value(), block_entry);
-    return block_entry;
+    const EmittedBlockInfo block_info = Emit(std::move(ir_block));
+
+    block_infos.insert_or_assign(descriptor.Value(), block_info);
+    block_entries.insert_or_assign(descriptor.Value(), block_info.entry_point);
+    return block_info.entry_point;
+}
+
+void A32AddressSpace::ClearCache() {
+    block_entries.clear();
+    block_infos.clear();
+    as.RewindBuffer(reinterpret_cast<char*>(prelude_info.end_of_prelude) - reinterpret_cast<char*>(as.GetBufferPointer(0)));
 }
 
 void A32AddressSpace::EmitPrelude() {
-    ASSERT_FALSE("Unimplemented");
+    using namespace biscuit;
+    prelude_info.run_code = reinterpret_cast<PreludeInfo::RunCodeFuncType>(as.GetCursorPointer());
+
+    // TODO: Minimize this.
+    as.ADDI(sp, sp, -64 * 8);
+    for (std::uint32_t i = 1; i < 32; i += 1) {
+        if (GPR{i} == sp || GPR{i} == tp)
+            continue;
+        as.SD(GPR{i}, i * 8, sp);
+    }
+    for (std::uint32_t i = 0; i < 32; i += 1) {
+        as.FSD(FPR{i}, 32 + i * 8, sp);
+    }
+
+    as.JALR(x0, 0, a0);
+
+    prelude_info.return_from_run_code = reinterpret_cast<void*>(as.GetCursorPointer());
+    for (std::uint32_t i = 1; i < 32; i += 1) {
+        if (GPR{i} == sp || GPR{i} == tp)
+            continue;
+        as.LD(GPR{i}, i * 8, sp);
+    }
+    for (std::uint32_t i = 0; i < 32; i += 1) {
+        as.FLD(FPR{i}, 32 + i * 8, sp);
+    }
+    as.ADDI(sp, sp, 64 * 8);
+    as.JALR(ra);
+
+    prelude_info.end_of_prelude = reinterpret_cast<u32*>(as.GetCursorPointer());
 }
 
-void* A32AddressSpace::Emit(IR::Block) {
-    ASSERT_FALSE("Unimplemented");
+size_t A32AddressSpace::GetRemainingSize() {
+    return conf.code_cache_size - (reinterpret_cast<uintptr_t>(as.GetCursorPointer()) - reinterpret_cast<uintptr_t>(as.GetBufferPointer(0)));
+}
+
+EmittedBlockInfo A32AddressSpace::Emit(IR::Block block) {
+    if (GetRemainingSize() < 1024 * 1024) {
+        ClearCache();
+    }
+
+    EmittedBlockInfo block_info = EmitRV64(as, std::move(block));
+    Link(block_info);
+
+    return block_info;
+}
+
+void A32AddressSpace::Link(EmittedBlockInfo& block_info) {
+    using namespace biscuit;
+    for (auto [ptr_offset, target] : block_info.relocations) {
+        Assembler a(reinterpret_cast<u8*>(reinterpret_cast<char*>(block_info.entry_point) + ptr_offset), 4);
+
+        switch (target) {
+        case LinkTarget::ReturnFromRunCode: {
+            std::ptrdiff_t off = reinterpret_cast<char*>(prelude_info.return_from_run_code) - reinterpret_cast<char*>(a.GetCursorPointer());
+            a.JAL(x0, off);
+            break;
+        }
+        default:
+            ASSERT_FALSE("Invalid relocation target");
+        }
+    }
 }
 
 }  // namespace Dynarmic::Backend::RV64

src/dynarmic/backend/riscv64/a32_address_space.h

@@ -5,8 +5,11 @@
 
 #pragma once
 
+#include <biscuit/assembler.hpp>
 #include <tsl/robin_map.h>
 
+#include "dynarmic/backend/riscv64/code_block.h"
+#include "dynarmic/backend/riscv64/emit_riscv64.h"
 #include "dynarmic/interface/A32/config.h"
 #include "dynarmic/interface/halt_reason.h"
 #include "dynarmic/ir/basic_block.h"
@@ -26,22 +29,31 @@ public:
 
     void* GetOrEmit(IR::LocationDescriptor descriptor);
 
+    void ClearCache();
+
 private:
     friend class A32Core;
 
     void EmitPrelude();
 
-    void* Emit(IR::Block ir_block);
+    size_t GetRemainingSize();
+    EmittedBlockInfo Emit(IR::Block ir_block);
+    void Link(EmittedBlockInfo& block);
 
     const A32::UserConfig conf;
 
+    CodeBlock cb;
+    biscuit::Assembler as;
+
     tsl::robin_map<u64, void*> block_entries;
+    tsl::robin_map<u64, EmittedBlockInfo> block_infos;
 
     struct PreludeInfo {
         u32* end_of_prelude;
 
         using RunCodeFuncType = HaltReason (*)(void* entry_point, A32JitState* context, volatile u32* halt_reason);
         RunCodeFuncType run_code;
+        void* return_from_run_code;
     } prelude_info;
 };
 

src/dynarmic/backend/riscv64/a32_interface.cpp

@@ -122,7 +122,7 @@ struct Jit::Impl final {
 
 private:
     void RequestCacheInvalidation() {
-        ASSERT_FALSE("Unimplemented");
+        // ASSERT_FALSE("Unimplemented");
 
         invalidate_entire_cache = false;
         invalid_cache_ranges.clear();

src/dynarmic/backend/riscv64/code_block.h

@@ -8,7 +8,6 @@
 #include <cstdint>
 #include <new>
 
-#include <biscuit/assembler.hpp>
 #include <sys/mman.h>
 
 namespace Dynarmic::Backend::RV64 {
@@ -17,7 +16,7 @@ class CodeBlock {
 public:
     explicit CodeBlock(std::size_t size)
             : memsize(size) {
-        mem = (std::uint32_t*)mmap(nullptr, size, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_ANON | MAP_PRIVATE, -1, 0);
+        mem = (std::uint8_t*)mmap(nullptr, size, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_ANON | MAP_PRIVATE, -1, 0);
 
         if (mem == nullptr)
             throw std::bad_alloc{};
@@ -30,13 +29,12 @@ public:
         munmap(mem, memsize);
     }
 
-    std::uint32_t* ptr() const {
+    std::uint8_t* ptr() const {
         return mem;
     }
 
 protected:
-    std::uint32_t* mem;
+    std::uint8_t* mem;
     std::size_t memsize = 0;
-    biscuit::Assembler as;
 };
 }  // namespace Dynarmic::Backend::RV64

src/dynarmic/backend/riscv64/emit_riscv64.cpp

@@ -0,0 +1,35 @@
+/* This file is part of the dynarmic project.
+ * Copyright (c) 2024 MerryMage
+ * SPDX-License-Identifier: 0BSD
+ */
+
+#include "dynarmic/backend/riscv64/emit_riscv64.h"
+
+#include <biscuit/assembler.hpp>
+
+#include "dynarmic/backend/riscv64/a32_jitstate.h"
+#include "dynarmic/ir/basic_block.h"
+
+namespace Dynarmic::Backend::RV64 {
+
+EmittedBlockInfo EmitRV64(biscuit::Assembler& as, [[maybe_unused]] IR::Block block) {
+    using namespace biscuit;
+
+    EmittedBlockInfo ebi;
+    ebi.entry_point = reinterpret_cast<void*>(as.GetCursorPointer());
+
+    as.ADDIW(a0, zero, 8);
+    as.SW(a0, offsetof(A32JitState, regs) + 0 * sizeof(u32), a1);
+
+    as.ADDIW(a0, zero, 2);
+    as.SW(a0, offsetof(A32JitState, regs) + 1 * sizeof(u32), a1);
+    as.SW(a0, offsetof(A32JitState, regs) + 15 * sizeof(u32), a1);
+
+    ebi.relocations[reinterpret_cast<char*>(as.GetCursorPointer()) - reinterpret_cast<char*>(ebi.entry_point)] = LinkTarget::ReturnFromRunCode;
+    as.NOP();
+
+    ebi.size = reinterpret_cast<size_t>(as.GetCursorPointer()) - reinterpret_cast<size_t>(ebi.entry_point);
+    return ebi;
+}
+
+}  // namespace Dynarmic::Backend::RV64

src/dynarmic/backend/riscv64/emit_riscv64.h

@@ -0,0 +1,33 @@
+/* This file is part of the dynarmic project.
+ * Copyright (c) 2024 MerryMage
+ * SPDX-License-Identifier: 0BSD
+ */
+
+#pragma once
+
+#include <mcl/stdint.hpp>
+#include <tsl/robin_map.h>
+
+namespace biscuit {
+class Assembler;
+}  // namespace biscuit
+
+namespace Dynarmic::IR {
+class Block;
+}  // namespace Dynarmic::IR
+
+namespace Dynarmic::Backend::RV64 {
+
+enum class LinkTarget {
+    ReturnFromRunCode,
+};
+
+struct EmittedBlockInfo {
+    void* entry_point;
+    size_t size;
+    tsl::robin_map<std::ptrdiff_t, LinkTarget> relocations;
+};
+
+EmittedBlockInfo EmitRV64(biscuit::Assembler& as, IR::Block block);
+
+}  // namespace Dynarmic::Backend::RV64

tests/CMakeLists.txt

@@ -60,6 +60,10 @@ if (DYNARMIC_TESTS_USE_UNICORN)
     endif()
 endif()
 
+if ("riscv" IN_LIST ARCHITECTURE)
+    target_link_libraries(dynarmic_tests PRIVATE biscuit::biscuit)
+endif()
+
 if ("x86_64" IN_LIST ARCHITECTURE)
     target_link_libraries(dynarmic_tests PRIVATE xbyak::xbyak)