allow to disable SH2 dynarec on runtime

Makefile

@@ -45,7 +45,6 @@ asm_mix ?= 1
 else # if not arm
 use_fame ?= 1
 use_cz80 ?= 1
-use_sh2mame ?= 1
 endif
 
 -include Makefile.local

Makefile.libretro

@@ -52,7 +52,6 @@ else ifeq ($(platform), ios)
    use_fame = 1
    use_drz80 = 0
    use_cz80 = 1
-   use_sh2mame = 0
    use_sh2drc = 1
    use_svpdrc = 1
 

cpu/drc/cmn.c

@@ -20,6 +20,7 @@ void drc_cmn_init(void)
     tcache, sizeof(tcache), ret);
 
 #ifdef __arm__
+  if (PicoOpt & POPT_EN_DRC)
   {
     static int test_done;
     if (!test_done)

cpu/sh2/compiler.c

@@ -3111,12 +3111,10 @@ void sh2_drc_wcheck_da(unsigned int a, int val, int cpuid)
     1 + cpuid, SH2_DRCBLK_DA_SHIFT, 0xfff);
 }
 
-int sh2_execute(SH2 *sh2c, int cycles)
+int sh2_execute_drc(SH2 *sh2c, int cycles)
 {
   int ret_cycles;
 
-  sh2c->cycles_timeslice = cycles;
-
   // cycles are kept in SHR_SR unused bits (upper 20)
   // bit11 contains T saved for delay slot
   // others are usual SH2 flags
@@ -3130,7 +3128,7 @@ int sh2_execute(SH2 *sh2c, int cycles)
     dbg(1, "warning: drc returned with cycles: %d", ret_cycles);
 
   sh2c->sr &= 0x3f3;
-  return sh2c->cycles_timeslice - ret_cycles;
+  return ret_cycles;
 }
 
 #if (DRC_DEBUG & 2)

cpu/sh2/mame/sh2pico.c

@@ -17,6 +17,38 @@ typedef unsigned short UINT16;
 typedef unsigned char  UINT8;
 #endif
 
+#ifdef DRC_SH2
+
+// this nasty conversion is needed for drc-expecting memhandlers
+#define MAKE_READFUNC(name, cname) \
+static inline unsigned int name(SH2 *sh2, unsigned int a) \
+{ \
+	unsigned int ret; \
+	sh2->sr |= sh2->icount << 12; \
+	ret = cname(a, sh2); \
+	sh2->icount = (signed int)sh2->sr >> 12; \
+	sh2->sr &= 0x3f3; \
+	return ret; \
+}
+
+#define MAKE_WRITEFUNC(name, cname) \
+static inline void name(SH2 *sh2, unsigned int a, unsigned int d) \
+{ \
+	sh2->sr |= sh2->icount << 12; \
+	cname(a, d, sh2); \
+	sh2->icount = (signed int)sh2->sr >> 12; \
+	sh2->sr &= 0x3f3; \
+}
+
+MAKE_READFUNC(RB, p32x_sh2_read8)
+MAKE_READFUNC(RW, p32x_sh2_read16)
+MAKE_READFUNC(RL, p32x_sh2_read32)
+MAKE_WRITEFUNC(WB, p32x_sh2_write8)
+MAKE_WRITEFUNC(WW, p32x_sh2_write16)
+MAKE_WRITEFUNC(WL, p32x_sh2_write32)
+
+#else
+
 #define RB(sh2, a) p32x_sh2_read8(a, sh2)
 #define RW(sh2, a) p32x_sh2_read16(a, sh2)
 #define RL(sh2, a) p32x_sh2_read32(a, sh2)
@@ -24,6 +56,8 @@ typedef unsigned char  UINT8;
 #define WW(sh2, a, d) p32x_sh2_write16(a, d, sh2)
 #define WL(sh2, a, d) p32x_sh2_write32(a, d, sh2)
 
+#endif
+
 // some stuff from sh2comn.h
 #define T	0x00000001
 #define S	0x00000002
@@ -71,14 +105,13 @@ static unsigned int op_refs[0x10000];
 
 #include "sh2.c"
 
-#ifndef DRC_SH2
 #ifndef DRC_CMP
 
-int sh2_execute(SH2 *sh2, int cycles)
+int sh2_execute_interpreter(SH2 *sh2, int cycles)
 {
 	UINT32 opcode;
 
-	sh2->icount = sh2->cycles_timeslice = cycles;
+	sh2->icount = cycles;
 
 	if (sh2->icount <= 0)
 		goto out;
@@ -134,12 +167,12 @@ int sh2_execute(SH2 *sh2, int cycles)
 	while (sh2->icount > 0 || sh2->delay);	/* can't interrupt before delay */
 
 out:
-	return sh2->cycles_timeslice - sh2->icount;
+	return sh2->icount;
 }
 
 #else // if DRC_CMP
 
-int sh2_execute(SH2 *sh2, int cycles)
+int sh2_execute_interpreter(SH2 *sh2, int cycles)
 {
 	static unsigned int base_pc_[2] = { 0, 0 };
 	static unsigned int end_pc_[2] = { 0, 0 };
@@ -233,11 +266,10 @@ int sh2_execute(SH2 *sh2, int cycles)
 	while (1);
 
 out:
-	return sh2->cycles_timeslice - sh2->icount;
+	return sh2->icount;
 }
 
 #endif // DRC_CMP
-#endif // DRC_SH2
 
 #ifdef SH2_STATS
 #include <stdio.h>

cpu/sh2/sh2.h

@@ -89,7 +89,23 @@ void sh2_do_irq(SH2 *sh2, int level, int vector);
 void sh2_pack(const SH2 *sh2, unsigned char *buff);
 void sh2_unpack(SH2 *sh2, const unsigned char *buff);
 
-int  sh2_execute(SH2 *sh2, int cycles);
+int  sh2_execute_drc(SH2 *sh2c, int cycles);
+int  sh2_execute_interpreter(SH2 *sh2c, int cycles);
+
+static inline int sh2_execute(SH2 *sh2, int cycles, int use_drc)
+{
+  int ret;
+
+  sh2->cycles_timeslice = cycles;
+#ifdef DRC_SH2
+  if (use_drc)
+    ret = sh2_execute_drc(sh2, cycles);
+  else
+#endif
+    ret = sh2_execute_interpreter(sh2, cycles);
+
+  return sh2->cycles_timeslice - ret;
+}
 
 // regs, pending_int*, cycles, reserved
 #define SH2_STATE_SIZE ((24 + 2 + 2 + 12) * 4)

pico/32x/32x.c

@@ -371,7 +371,7 @@ static inline void run_sh2(SH2 *sh2, int m68k_cycles)
   elprintf_sh2(sh2, EL_32X, "+run %u %d @%08x",
     sh2->m68krcycles_done, cycles, sh2->pc);
 
-  done = sh2_execute(sh2, cycles);
+  done = sh2_execute(sh2, cycles, PicoOpt & POPT_EN_DRC);
 
   sh2->m68krcycles_done += C_SH2_TO_M68K(*sh2, done);
   sh2->state &= ~SH2_STATE_RUN;

platform/common/common.mak

@@ -165,10 +165,7 @@ SRCS_COMMON += $(R)platform/libpicofe/linux/host_dasm.c
 LDFLAGS += -lbfd -lopcodes -liberty
 endif
 endif # use_sh2drc
-#
-ifeq "$(use_sh2mame)" "1"
 SRCS_COMMON += $(R)cpu/sh2/mame/sh2pico.c
-endif
 endif # !no_32x
 
 OBJS_COMMON := $(SRCS_COMMON:.c=.o)

platform/libretro.c

@@ -185,6 +185,9 @@ void retro_set_environment(retro_environment_t cb)
 		//{ "region", "Region; Auto|NTSC|PAL" },
 		{ "picodrive_input1", "Input device 1; 3 button pad|6 button pad|None" },
 		{ "picodrive_input2", "Input device 2; 3 button pad|6 button pad|None" },
+#ifdef DRC_SH2
+		{ "picodrive_drc", "Dynamic recompilers; enabled|disabled" },
+#endif
 		{ NULL, NULL },
 	};
 
@@ -688,6 +691,17 @@ static void update_variables(void)
 	var.key = "picodrive_input2";
 	if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && var.value)
 		PicoSetInputDevice(1, input_name_to_val(var.value));
+
+#ifdef DRC_SH2
+	var.value = NULL;
+	var.key = "picodrive_drc";
+	if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && var.value) {
+		if (strcmp(var.value, "enabled") == 0)
+			PicoOpt |= POPT_EN_DRC;
+		else
+			PicoOpt &= ~POPT_EN_DRC;
+	}
+#endif
 }
 
 void retro_run(void)