Made 68030 MMU last write special case optional, can be useful when debugging. Remove...

diff --git a/gencpu.cpp b/gencpu.cpp
index 25e8a107b292be1f4b98c2a5bf07fb43e53282f3..5679b9d10283c8a15332c69952f3dfae62e6938f 100644 (file)
--- a/gencpu.cpp
+++ b/gencpu.cpp
@@ -29,6 +29,10 @@
 #define xBCD_KEEPS_N_FLAG 4
 #define xBCD_KEEPS_V_FLAG 2
 
+// if set: 68030 MMU and instruction's last memory access is write and it causes fault:
+// instruction is considered completed, generate short bus error stack frame.
+#define MMU68030_LAST_WRITE 1
+
 static FILE *headerfile;
 static FILE *stblfile;
 
@@ -872,12 +876,7 @@ static void clearmmufixup (int cnt)
        }
 }
 
-static bool is_gen_set_fault_pc(void)
-{
-       return using_mmu == 68040 || using_mmu == 68030;
-}
-
-static void gen_set_fault_pc (bool multi)
+static void gen_set_fault_pc (bool multi, bool not68030)
 {
        int m68k_pc_total_old = m68k_pc_total;
        if (using_mmu == 68040) {
@@ -887,6 +886,10 @@ static void gen_set_fault_pc (bool multi)
                m68k_pc_offset = 0;
                clearmmufixup(0);
        } else if (using_mmu == 68030) {
+               if (!MMU68030_LAST_WRITE)
+                       return;
+               if (not68030)
+                       return;
                sync_m68k_pc();
                printf("\tregs.instruction_pc = %s;\n", getpc);
                printf("\tmmu030_state[1] |= MMU030_STATEFLAG1_LASTWRITE;\n");
@@ -1891,7 +1894,7 @@ static void genastore_2 (const char *from, amodes mode, const char *reg, wordsiz
                const char *dstwx = !(flags & GF_FC) ? dstw : "dfc_nommu_put_word";
                const char *dstlx = !(flags & GF_FC) ? dstl : "dfc_nommu_put_long";
                if (!(flags & GF_NOFAULTPC))
-                       gen_set_fault_pc (false);
+                       gen_set_fault_pc (false, false);
                if (using_mmu) {
                        switch (size) {
                        case sz_byte:
@@ -2188,7 +2191,7 @@ static void movem_mmu030 (const char *code, int size, bool put, bool aipi, bool
                dphase = 0;
                index = "movem_index1";
        }
-       if (put) {
+       if (put && MMU68030_LAST_WRITE) {
                printf("\tint prefetch = 0;\n");
        }
        printf ("\tmmu030_state[1] |= MMU030_STATEFLAG1_MOVEM1;\n");
@@ -2216,19 +2219,21 @@ static void movem_mmu030 (const char *code, int size, bool put, bool aipi, bool
                printf ("\t\t\t} else {\n");
                if (put) {
                        printf("\t\t\t\tmmu030_data_buffer_out = m68k_%creg(regs, %s[%cmask]);\n", reg, index, reg);
-                       // last write?
-                       if (dphase == i)
-                               printf("\t\t\t\tif(!amask && !nextmask) {\n");
-                       else
-                               printf("\t\t\t\tif(!dmask && !nextmask) {\n");
-                       get_prefetch_020();
-                       gen_set_fault_pc(true);
-                       printf("\t\t\t\t\tmmu030_state[1] &= ~MMU030_STATEFLAG1_MOVEM1;\n");
-                       m68k_pc_offset = old_m68k_pc_offset;
-                       printf("\t\t\t\t\tprefetch = 1;\n");
-                       if (aipi || apdi)
-                               printf("\tm68k_areg (regs, dstreg) = srca;\n");
-                       printf("\t\t\t\t}\n");
+                       if (MMU68030_LAST_WRITE) {
+                               // last write?
+                               if (dphase == i)
+                                       printf("\t\t\t\tif(!amask && !nextmask) {\n");
+                               else
+                                       printf("\t\t\t\tif(!dmask && !nextmask) {\n");
+                               get_prefetch_020();
+                               gen_set_fault_pc(true, false);
+                               printf("\t\t\t\t\tmmu030_state[1] &= ~MMU030_STATEFLAG1_MOVEM1;\n");
+                               m68k_pc_offset = old_m68k_pc_offset;
+                               printf("\t\t\t\t\tprefetch = 1;\n");
+                               if (aipi || apdi)
+                                       printf("\tm68k_areg (regs, dstreg) = srca;\n");
+                               printf("\t\t\t\t}\n");
+                       }
                        printf("\t\t\t\t%s, mmu030_data_buffer_out);\n", code);
                } else {
                        printf("\t\t\t\tval = %s;\n", code);
@@ -2248,14 +2253,20 @@ static void movem_mmu030 (const char *code, int size, bool put, bool aipi, bool
        if (aipi || apdi)
                printf ("\tm68k_areg (regs, dstreg) = srca;\n");
        if (put) {
-               // if both masks are zero
-               printf("\tif(prefetch == 0) {\n");
-               if (using_prefetch_020) {
-                       get_prefetch_020();
+               if (MMU68030_LAST_WRITE) {
+                       // if both masks are zero
+                       printf("\tif(prefetch == 0) {\n");
+                       if (using_prefetch_020) {
+                               get_prefetch_020();
+                       }
+                       sync_m68k_pc();
+                       printf("\t}\n");
+                       m68k_pc_offset = 0;
+               } else {
+                       if (using_prefetch_020) {
+                               get_prefetch_020();
+                       }
                }
-               sync_m68k_pc();
-               printf("\t}\n");
-               m68k_pc_offset = 0;
        }
 }
 
@@ -3868,7 +3879,7 @@ static void gen_opcode (unsigned int opcode)
                break;
        case i_TRAP:
                genamode (curi, curi->smode, "srcreg", curi->size, "src", 1, 0, 0);
-               gen_set_fault_pc (false);
+               gen_set_fault_pc (false, true);
                sync_m68k_pc ();
                printf ("\tException_cpu(src + 32);\n");
                did_prefetch = 1;
@@ -5096,7 +5107,7 @@ bccl_not68020:
                        printf ("\tint ru = (src >> 6) & 7;\n");
                        printf ("\tint rc = src & 7;\n");
                        genflags (flag_cmp, curi->size, "newv", "m68k_dreg (regs, rc)", "dst");
-                       gen_set_fault_pc (false);
+                       gen_set_fault_pc (false, true);
                        printf ("\tif (GET_ZFLG ()) ");
                        old_brace_level = n_braces;
                        start_brace ();
@@ -5345,7 +5356,7 @@ bccl_not68020:
                        printf ("\tval += %s;\n", gen_nextiword(0));
                        addmmufixup ("dstreg");
                        printf ("\tm68k_areg (regs, dstreg) -= areg_byteinc[dstreg];\n");
-                       gen_set_fault_pc (false);
+                       gen_set_fault_pc (false, false);
                        printf ("\t%s (m68k_areg (regs, dstreg),((val >> 4) & 0xf0) | (val & 0xf));\n", dstb);
                }
                break;
@@ -5370,7 +5381,7 @@ bccl_not68020:
                                printf ("\tm68k_areg (regs, dstreg) -= areg_byteinc[dstreg];\n");
                                printf ("\t%s (m68k_areg (regs, dstreg),val);\n", dstb);
                                printf ("\tm68k_areg (regs, dstreg) -= areg_byteinc[dstreg];\n");
-                               gen_set_fault_pc (false);
+                               gen_set_fault_pc (false, false);
                                printf ("\t%s (m68k_areg (regs, dstreg),val >> 8);\n", dstb);
                        }
                }