lightrec: Run dynarec until next interrupt

Instead of running the dynarec once per block, which creates a huge
overhead as entering/exiting the dynarec isn't very fast, run only the
number of cycles until the next interrupt.

This boosts performance by a huge margin. On my PC, running the intro
video in MediEvil goes from using 34-36% CPU usage down to 16-17%.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Co-developed-by: notaz <notasas@gmail.com>
Signed-off-by: notaz <notasas@gmail.com>

diff --git a/libpcsxcore/lightrec/plugin.c b/libpcsxcore/lightrec/plugin.c
index 7891943..2648cc3 100644 (file)
--- a/libpcsxcore/lightrec/plugin.c
+++ b/libpcsxcore/lightrec/plugin.c
@@ -48,6 +48,7 @@ static bool use_lightrec_interpreter;
 static bool use_pcsx_interpreter;
 static bool lightrec_debug;
 static bool lightrec_very_debug;
+static bool booting;
 static u32 lightrec_begin_cycles;
 
 enum my_cp2_opcodes {
@@ -126,15 +127,28 @@ static u32 cop2_cfc(struct lightrec_state *state, u32 op, u8 reg)
        return cop2_mfc_cfc(state, reg, true);
 }
 
+static bool has_interrupt(void)
+{
+       return ((psxHu32(0x1070) & psxHu32(0x1074)) &&
+            (psxRegs.CP0.n.Status & 0x401) == 0x401) ||
+           (psxRegs.CP0.n.Status & psxRegs.CP0.n.Cause & 0x0300);
+}
+
 static void lightrec_restore_state(struct lightrec_state *state)
 {
        lightrec_reset_cycle_count(state, psxRegs.cycle);
-       lightrec_set_exit_flags(state, LIGHTREC_EXIT_CHECK_INTERRUPT);
+
+       if (booting || has_interrupt())
+               lightrec_set_exit_flags(state, LIGHTREC_EXIT_CHECK_INTERRUPT);
+       else
+               lightrec_set_target_cycle_count(state, next_interupt);
 }
 
 static void cop0_mtc_ctc(struct lightrec_state *state,
                         u8 reg, u32 value, bool ctc)
 {
+       psxRegs.cycle = lightrec_current_cycle_count(state);
+
        switch (reg) {
        case 1:
        case 4:
@@ -493,6 +507,7 @@ static void print_for_big_ass_debugger(void)
 
 
 extern void intExecuteBlock();
+extern void gen_interupt();
 
 static u32 old_cycle_counter;
 
@@ -501,18 +516,24 @@ static void lightrec_plugin_execute_block(void)
        u32 old_pc = psxRegs.pc;
        u32 flags;
 
+       gen_interupt();
+
        if (use_pcsx_interpreter) {
                intExecuteBlock();
        } else {
                lightrec_reset_cycle_count(lightrec_state, psxRegs.cycle);
                lightrec_restore_registers(lightrec_state, psxRegs.GPR.r);
 
-               if (use_lightrec_interpreter)
+               if (unlikely(use_lightrec_interpreter))
                        psxRegs.pc = lightrec_run_interpreter(lightrec_state,
                                                              psxRegs.pc);
-               else
+               // step during early boot so that 0x80030000 fastboot hack works
+               else if (unlikely(booting))
                        psxRegs.pc = lightrec_execute_one(lightrec_state,
                                                          psxRegs.pc);
+               else
+                       psxRegs.pc = lightrec_execute(lightrec_state,
+                                                     psxRegs.pc, next_interupt);
 
                psxRegs.cycle = lightrec_current_cycle_count(lightrec_state);
 
@@ -527,9 +548,10 @@ static void lightrec_plugin_execute_block(void)
 
                if (flags & LIGHTREC_EXIT_SYSCALL)
                        psxException(0x20, 0);
-       }
 
-       psxBranchTest();
+               if (booting && (psxRegs.pc & 0xff800000) == 0x80000000)
+                       booting = false;
+       }
 
        if (lightrec_debug && psxRegs.cycle >= lightrec_begin_cycles
                        && psxRegs.pc != old_pc)
@@ -602,6 +624,7 @@ static void lightrec_plugin_reset(void)
 {
        lightrec_plugin_shutdown();
        lightrec_plugin_init();
+       booting = true;
 }
 
 R3000Acpu psxRec =