68000 bus error emulation updates.

diff --git a/gencpu.cpp b/gencpu.cpp
index 4ae77af4c921459ceec2bc22abb6e205b1e412de..88054bee9ead66f137a0ada83edf5e7465ca856f 100644 (file)
--- a/gencpu.cpp
+++ b/gencpu.cpp
@@ -482,9 +482,12 @@ static void add_mmu040_movem (int movem)
 }
 
 static char bus_error_text[200];
+static int bus_error_specials;
 
 static void do_instruction_buserror(void)
 {
+       if (!using_bus_error)
+               return;
        if (bus_error_text[0]) {
                printf("\tif(cpu_bus_error) {\n");
                printf("%s", bus_error_text);
@@ -492,16 +495,35 @@ static void do_instruction_buserror(void)
                need_endlabel = 1;
                printf("\t}\n");
                bus_error_text[0] = 0;
+               bus_error_specials = 0;
        }
 }
 
 static void check_bus_error_ins(int offset)
 {
-       sprintf(bus_error_text, "\t\texception2_read(opcode, m68k_getpci() + %d, 2);\n", offset);
+       char *opcode;
+       if (bus_error_specials) {
+               opcode = "0";
+       } else {
+               opcode = "opcode";
+       }
+       sprintf(bus_error_text, "\t\texception2_read(%s, m68k_getpci() + %d, 2);\n", opcode, offset);
 }
 
 static void check_prefetch_bus_error(int offset)
 {
+       if (!using_bus_error)
+               return;
+       if (offset < 0) {
+               if (offset == -1)
+                       offset = 0;
+               else
+                       offset = 2;
+               // full prefetch: opcode field is zero
+               if (offset == 2) {
+                       bus_error_specials = 1;
+               }
+       }
        check_bus_error_ins(offset);
        do_instruction_buserror();
 }
@@ -553,6 +575,7 @@ static void gen_nextilong2 (const char *type, const char *name, int flags, int m
 static void gen_nextilong (const char *type, const char *name, int flags)
 {
        bus_error_text[0] = 0;
+       bus_error_specials = 0;
        gen_nextilong2 (type, name, flags, 0);
 }
 
@@ -563,6 +586,7 @@ static const char *gen_nextiword (int flags)
        m68k_pc_offset += 2;
 
        bus_error_text[0] = 0;
+       bus_error_specials = 0;
        if (using_ce020) {
                if (flags & GF_NOREFILL)
                        sprintf(buffer, "%s (%d)", prefetch_word, r);
@@ -603,6 +627,7 @@ static const char *gen_nextibyte (int flags)
        m68k_pc_offset += 2;
 
        bus_error_text[0] = 0;
+       bus_error_specials = 0;
        if (using_ce020 || using_prefetch_020) {
                if (flags & GF_NOREFILL)
                        sprintf(buffer, "(uae_u8)%s (%d)", prefetch_word, r);
@@ -723,12 +748,25 @@ static void fill_prefetch_1 (int o)
        }
 }
 
+// complete prefetch
+static void fill_prefetch_1_empty(int o)
+{
+       if (using_prefetch) {
+               printf("\t%s (%d);\n", prefetch_word, o);
+               check_prefetch_bus_error(o ? -2 : -1);
+               did_prefetch = 1;
+               ir2irc = 0;
+               count_read++;
+               insn_n_cycles += 4;
+       }
+}
+
 static void fill_prefetch_full_2 (void)
 {
        if (using_prefetch) {
-               fill_prefetch_1 (0);
+               fill_prefetch_1_empty (0);
                irc2ir ();
-               fill_prefetch_1 (2);
+               fill_prefetch_1_empty (2);
        } else if (isprefetch020()) {
                did_prefetch = 2;
                total_ce020 -= 4;
@@ -744,9 +782,9 @@ static void fill_prefetch_full_2 (void)
 static void fill_prefetch_full_ntx (void)
 {
        if (using_prefetch) {
-               fill_prefetch_1 (0);
+               fill_prefetch_1_empty(0);
                irc2ir ();
-               fill_prefetch_1 (2);
+               fill_prefetch_1_empty(2);
        } else if (isprefetch020()) {
                did_prefetch = 2;
                total_ce020 -= 4;
@@ -779,9 +817,9 @@ static void trace_t0_68040_only(void)
 static void fill_prefetch_full (void)
 {
        if (using_prefetch) {
-               fill_prefetch_1 (0);
+               fill_prefetch_1_empty(0);
                irc2ir ();
-               fill_prefetch_1 (2);
+               fill_prefetch_1_empty(2);
        } else if (isprefetch020()) {
                did_prefetch = 2;
                total_ce020 -= 4;
@@ -836,16 +874,11 @@ static void dummy_prefetch (void)
        insn_n_cycles += 4;
 }
 
-static void fill_prefetch_next_1 (void)
-{
-       irc2ir ();
-       fill_prefetch_1 (m68k_pc_offset + 2);
-}
-
 static void fill_prefetch_next (void)
 {
        if (using_prefetch) {
-               fill_prefetch_next_1 ();
+               irc2ir();
+               fill_prefetch_1(m68k_pc_offset + 2);
        }
 //     if (using_prefetch_020) {
 //             printf ("\t%s (%d);\n", prefetch_word, m68k_pc_offset);
@@ -853,6 +886,14 @@ static void fill_prefetch_next (void)
 //     }
 }
 
+static void fill_prefetch_next_empty(void)
+{
+       if (using_prefetch) {
+               irc2ir();
+               fill_prefetch_1_empty(m68k_pc_offset + 2);
+       }
+}
+
 static void fill_prefetch_finish (void)
 {
        if (did_prefetch)
@@ -996,8 +1037,8 @@ static void check_bus_error(const char *name, int offset, int write, int fc)
                        break;
                case 4:
                        if ((g_instr->mnemo == i_ADDX || g_instr->mnemo == i_SUBX) && g_instr->size == sz_long) {
-                               // ADDX.L/SUBX.L -(an),-(an): not decreased
-                               ;
+                               // ADDX.L/SUBX.L -(an),-(an) source: stack frame decreased by 2, not 4.
+                               offset = 2;
                        } else {
                                printf("\t\tm68k_areg (regs, %s) = %sa;\n", bus_error_reg, name);
                        }
@@ -2057,7 +2098,7 @@ static void genamode2x (amodes mode, const char *reg, wordsizes size, const char
                                        printf("\tuae_s32 %s = %s (%sa + 2);\n", name, srcwx, name);
                                        check_bus_error(name, 0, 0, 1);
                                        printf("\t%s |= % s(% sa) << 16; \n", name, srcw, name);
-                                       check_bus_error(name, 0, 0, 1);
+                                       check_bus_error(name, -2, 0, 1);
                                } else {
                                        printf("\tuae_s32 %s = %s (%sa) << 16;\n", name, srcwx, name);
                                        check_bus_error(name, 0, 0, 1);
@@ -4084,18 +4125,21 @@ static void gen_opcode (unsigned int opcode)
                if (curi->size == sz_word) {
                        printf ("\tuae_u16 val  = (%s (mempa) & 0xff) << 8;\n", srcb);
                        check_bus_error("memp", 0, 0, 1);
-                       printf ("\t        val |= (%s (mempa + 2) & 0xff);\n", srcb);
+                       printf ("\tval |= (%s (mempa + 2) & 0xff);\n", srcb);
                        check_bus_error("memp", 2, 0, 1);
                        count_read += 2;
                } else {
                        printf ("\tuae_u32 val  = (%s (mempa) & 0xff) << 24;\n", srcb);
                        check_bus_error("memp", 0, 0, 1);
-                       printf ("\t        val |= (%s (mempa + 2) & 0xff) << 16;\n", srcb);
+                       printf ("\tval |= (%s (mempa + 2) & 0xff) << 16;\n", srcb);
                        check_bus_error("memp", 2, 0, 1);
-                       printf ("\t        val |= (%s (mempa + 4) & 0xff) << 8;\n", srcb);
+
+                       // upper word gets updated after two bytes (makes only difference if bus error is possible)
+                       printf("\tm68k_dreg(regs, dstreg) = (m68k_dreg(regs, dstreg) & 0x0000ffff) | (val & 0xffff0000);\n");
+
+                       printf("\tval |= (%s (mempa + 4) & 0xff) << 8;\n", srcb);
                        check_bus_error("memp", 4, 0, 1);
-                       printf ("\t        val |= (%s (mempa + 6) & 0xff);\n", srcb);
-                       printf ("\t        val |= (%s (mempa + 6) & 0xff);\n", srcb);
+                       printf ("\tval |= (%s (mempa + 6) & 0xff);\n", srcb);
                        check_bus_error("memp", 6, 0, 1);
                        count_read += 4;
                }
@@ -4246,7 +4290,8 @@ static void gen_opcode (unsigned int opcode)
                } else {
                        // read first and ignore result
                        if (cpu_level <= 1 && curi->size == sz_word) {
-                               printf ("\t%s (srca);\n", srcw);
+                               printf("\t%s (srca);\n", srcw);
+                               check_bus_error("src", 0, 0, 1);
                                count_write++;
                        }
                        fill_prefetch_next ();
@@ -4765,16 +4810,8 @@ static void gen_opcode (unsigned int opcode)
                                if (cpu_level <= 1 && using_prefetch)
                                        printf ("\tnextpc += 2;\n");
                        }
-                       if (cpu_level < 4)
-                               printf("\tm68k_areg (regs, 7) -= 4;\n");
-                       if (using_exception_3 && cpu_level <= 1) {
-                               printf("\tif (m68k_areg(regs, 7) & 1) {\n");
-                               printf("\t\texception3_write(opcode, m68k_areg(regs, 7), 1);\n");
-                               printf("\t\tgoto %s;\n", endlabelstr);
-                               printf("\t}\n");
-                               need_endlabel = 1;
-                       }
                        setpc ("srca");
+                       clear_m68k_offset();
                        if (using_exception_3 && cpu_level >= 2) {
                                printf("\tif (%s & 1) {\n", getpc);
                                printf("\t\texception3i (opcode, %s);\n", getpc);
@@ -4782,10 +4819,16 @@ static void gen_opcode (unsigned int opcode)
                                printf("\t}\n");
                                need_endlabel = 1;
                        }
-                       if (cpu_level >= 4)
+                       fill_prefetch_1(0);
+                       if (cpu_level < 4)
                                printf("\tm68k_areg (regs, 7) -= 4;\n");
-                       clear_m68k_offset();
-                       fill_prefetch_1 (0);
+                       if (using_exception_3 && cpu_level <= 1) {
+                               printf("\tif (m68k_areg(regs, 7) & 1) {\n");
+                               printf("\t\texception3_write(opcode, m68k_areg(regs, 7), 1);\n");
+                               printf("\t\tgoto %s;\n", endlabelstr);
+                               printf("\t}\n");
+                               need_endlabel = 1;
+                       }
                        if (using_ce || using_prefetch) {
                                printf("\tuaecptr dsta = m68k_areg(regs, 7);\n");
                                printf("\t%s(dsta, nextpc >> 16);\n", dstw);
@@ -4793,8 +4836,10 @@ static void gen_opcode (unsigned int opcode)
                                printf("\t%s(dsta + 2, nextpc);\n", dstw);
                                check_bus_error("dst", 2, 1, 1);
                        } else {
-                               printf ("\t%s(m68k_areg(regs, 7), nextpc);\n", dstl);
+                               printf("\t%s(m68k_areg(regs, 7), nextpc);\n", dstl);
                        }
+                       if (cpu_level >= 4)
+                               printf("\tm68k_areg (regs, 7) -= 4;\n");
                        if (using_debugmem) {
                                printf("\tif (debugmem_trace)\n");
                                printf("\t\tbranch_stack_push(oldpc, nextpc);\n");
@@ -4802,7 +4847,7 @@ static void gen_opcode (unsigned int opcode)
                }
                count_write += 2;
                fill_prefetch_full_020 ();
-               fill_prefetch_next ();
+               fill_prefetch_next_empty();
                branch_inst = 1;
                next_level_040_to_030();
                break;