From 6124dfd8977f5e0d1e73ccbd818554e393e8d624 Mon Sep 17 00:00:00 2001
From: Maxim Poliakovski <maximumspatium@googlemail.com>
Date: Sat, 14 Nov 2020 03:05:06 +0100
Subject: [PATCH] Add virtual CPU benchmarking code.

---
 CMakeLists.txt       | 10 +++++
 benchmark/bench1.cpp | 91 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 101 insertions(+)
 create mode 100644 benchmark/bench1.cpp

diff --git a/CMakeLists.txt b/CMakeLists.txt
index d9dd0e9..c7b6bb8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -89,6 +89,16 @@ else()
 target_link_libraries(testppc cubeb ${SDL2_LIBRARIES} ${CMAKE_DL_LIBS} ${CMAKE_THREAD_LIBS_INIT})
 endif()
 
+file(GLOB BENCH_SOURCES "${PROJECT_SOURCE_DIR}/benchmark/*.cpp")
+add_executable(bench1 ${BENCH_SOURCES} $<TARGET_OBJECTS:debugger>
+                                       $<TARGET_OBJECTS:cpu_ppc>
+                                       $<TARGET_OBJECTS:devices>
+                                       $<TARGET_OBJECTS:execution>
+                                       $<TARGET_OBJECTS:machines>
+                                       $<TARGET_OBJECTS:loguru>)
+
+target_link_libraries(bench1 cubeb ${SDL2_LIBRARIES} ${CMAKE_DL_LIBS} ${CMAKE_THREAD_LIBS_INIT})
+
 add_custom_command(
     TARGET testppc POST_BUILD
     COMMAND ${CMAKE_COMMAND} -E copy
diff --git a/benchmark/bench1.cpp b/benchmark/bench1.cpp
new file mode 100644
index 0000000..b994b32
--- /dev/null
+++ b/benchmark/bench1.cpp
@@ -0,0 +1,91 @@
+#include <stdlib.h>
+#include <chrono>
+#include "cpu/ppc/ppcemu.h"
+#include "cpu/ppc/ppcmmu.h"
+#include "devices/mpc106.h"
+#include <thirdparty/loguru/loguru.hpp>
+
+uint32_t cs_code[] = {
+    0x3863FFFC, 0x7C861671, 0x41820090, 0x70600002, 0x41E2001C, 0xA0030004,
+    0x3884FFFE, 0x38630002, 0x5486F0BF, 0x7CA50114, 0x41820070, 0x70C60003,
+    0x41820014, 0x7CC903A6, 0x84030004, 0x7CA50114, 0x4200FFF8, 0x5486E13F,
+    0x41820050, 0x80030004, 0x7CC903A6, 0x80C30008, 0x7CA50114, 0x80E3000C,
+    0x7CA53114, 0x85030010, 0x7CA53914, 0x42400028, 0x80030004, 0x7CA54114,
+    0x80C30008, 0x7CA50114, 0x80E3000C, 0x7CA53114, 0x85030010, 0x7CA53914,
+    0x4200FFE0, 0x7CA54114, 0x70800002, 0x41E20010, 0xA0030004, 0x38630002,
+    0x7CA50114, 0x70800001, 0x41E20010, 0x88030004, 0x5400402E, 0x7CA50114,
+    0x7C650194, 0x4E800020
+};
+
+
+int main(int argc, char** argv) {
+    int i;
+
+    /* initialize logging */
+    loguru::g_preamble_date    = false;
+    loguru::g_preamble_time    = false;
+    loguru::g_preamble_thread  = false;
+
+    loguru::g_stderr_verbosity = 0;
+    loguru::init(argc, argv);
+
+    MPC106* grackle_obj = new MPC106;
+
+    /* we need some RAM */
+    if (!grackle_obj->add_ram_region(0, 0x9000)) {
+        LOG_F(ERROR, "Could not create RAM region");
+        delete(grackle_obj);
+        return -1;
+    }
+
+    ppc_cpu_init(grackle_obj, PPC_VER::MPC750);
+
+    /* load executable code into RAM at address 0 */
+    for (i = 0; i < sizeof(cs_code); i++) {
+        mem_write_dword(i*4, cs_code[i]);
+    }
+
+    srand(0xCAFEBABE);
+
+    for (i = 0; i < 32768; i++) {
+        mem_write_byte(0x1000+i, rand() % 256);
+    }
+
+    /* prepare benchmark code execution */
+    ppc_state.pc = 0;
+    ppc_state.gpr[3] = 0x1000; // buf
+    ppc_state.gpr[4] = 0x8000; // len
+    ppc_state.gpr[5] = 0;      // sum
+
+    ppc_exec_until(0xC4);
+
+    LOG_F(INFO, "Checksum: 0x%08X", ppc_state.gpr[3]);
+
+    // run the clock once for cache fill etc.
+    auto start_time   = std::chrono::steady_clock::now();
+    auto end_time     = std::chrono::steady_clock::now();
+    auto time_elapsed = std::chrono::duration_cast<std::chrono::nanoseconds>(end_time - start_time);
+    LOG_F(INFO, "Time elapsed (dry run): %lld ns", time_elapsed.count());
+
+    for (i = 0; i < 5; i++) {
+        ppc_state.pc = 0;
+        ppc_state.gpr[3] = 0x1000; // buf
+        ppc_state.gpr[4] = 0x8000; // len
+        ppc_state.gpr[5] = 0;      // sum
+
+        auto start_time = std::chrono::steady_clock::now();
+
+        ppc_exec_until(0xC4);
+
+        auto end_time = std::chrono::steady_clock::now();
+
+        LOG_F(INFO, "Checksum: 0x%08X", ppc_state.gpr[3]);
+
+        auto time_elapsed = std::chrono::duration_cast<std::chrono::nanoseconds>(end_time - start_time);
+        LOG_F(INFO, "Time elapsed (run #%d): %lld ns", i, time_elapsed.count());
+    }
+
+    delete(grackle_obj);
+
+    return 0;
+}