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Fix xBCD instruction for 68040 emulation: the NV flags shall not be affected.

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This commit is contained in:
gbeauche 2007-06-30 08:00:31 +00:00
parent 35bf8b2c25
commit a5778cd5cb
1 changed files with 38 additions and 6 deletions
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44
BasiliskII/src/uae_cpu/gencpu.c
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@ -30,6 +30,9 @@
#define BOOL_TYPE "int"
/* Define the minimal 680x0 where NV flags are not affected by xBCD instructions. */
#define xBCD_KEEPS_NV_FLAGS 4
static FILE *headerfile;
static FILE *stblfile;
@ -568,7 +571,7 @@ static void duplicate_carry (void)
}
typedef enum {
flag_logical_noclobber, flag_logical, flag_add, flag_sub, flag_cmp, flag_addx, flag_subx, flag_zn,
flag_logical_noclobber, flag_logical, flag_add, flag_sub, flag_cmp, flag_addx, flag_subx, flag_z, flag_zn,
flag_av, flag_sv
} flagtypes;
@ -622,6 +625,7 @@ static void genflags_normal (flagtypes type, wordsizes size, char *value, char *
switch (type) {
case flag_logical_noclobber:
case flag_logical:
case flag_z:
case flag_zn:
case flag_av:
case flag_sv:
@ -643,6 +647,7 @@ static void genflags_normal (flagtypes type, wordsizes size, char *value, char *
switch (type) {
case flag_logical_noclobber:
case flag_logical:
case flag_z:
case flag_zn:
break;
@ -676,6 +681,9 @@ static void genflags_normal (flagtypes type, wordsizes size, char *value, char *
case flag_sv:
printf ("\tSET_VFLG ((flgs ^ flgo) & (flgn ^ flgo));\n");
break;
case flag_z:
printf ("\tSET_ZFLG (GET_ZFLG & (%s == 0));\n", vstr);
break;
case flag_zn:
printf ("\tSET_ZFLG (GET_ZFLG & (%s == 0));\n", vstr);
printf ("\tSET_NFLG (%s < 0);\n", vstr);
@ -921,8 +929,16 @@ static void gen_opcode (unsigned long int opcode)
printf ("\tif ((((dst & 0xFF) - (src & 0xFF) - (GET_XFLG ? 1 : 0)) & 0x100) > 0xFF) { newv -= 0x60; }\n");
printf ("\tSET_CFLG ((((dst & 0xFF) - (src & 0xFF) - bcd - (GET_XFLG ? 1 : 0)) & 0x300) > 0xFF);\n");
duplicate_carry ();
genflags (flag_zn, curi->size, "newv", "", "");
printf ("\tSET_VFLG ((tmp_newv & 0x80) != 0 && (newv & 0x80) == 0);\n");
/* Manual says bits NV are undefined though a real 68040 don't change them */
if (cpu_level >= xBCD_KEEPS_NV_FLAGS) {
if (next_cpu_level < xBCD_KEEPS_NV_FLAGS)
next_cpu_level = xBCD_KEEPS_NV_FLAGS - 1;
genflags (flag_z, curi->size, "newv", "", "");
}
else {
genflags (flag_zn, curi->size, "newv", "", "");
printf ("\tSET_VFLG ((tmp_newv & 0x80) != 0 && (newv & 0x80) == 0);\n");
}
genastore ("newv", curi->dmode, "dstreg", curi->size, "dst");
break;
case i_ADD:
@ -962,8 +978,16 @@ static void gen_opcode (unsigned long int opcode)
printf ("\tif (cflg) newv += 0x60;\n");
printf ("\tSET_CFLG (cflg);\n");
duplicate_carry ();
genflags (flag_zn, curi->size, "newv", "", "");
printf ("\tSET_VFLG ((tmp_newv & 0x80) == 0 && (newv & 0x80) != 0);\n");
/* Manual says bits NV are undefined though a real 68040 don't change them */
if (cpu_level >= xBCD_KEEPS_NV_FLAGS) {
if (next_cpu_level < xBCD_KEEPS_NV_FLAGS)
next_cpu_level = xBCD_KEEPS_NV_FLAGS - 1;
genflags (flag_z, curi->size, "newv", "", "");
}
else {
genflags (flag_zn, curi->size, "newv", "", "");
printf ("\tSET_VFLG ((tmp_newv & 0x80) == 0 && (newv & 0x80) != 0);\n");
}
genastore ("newv", curi->dmode, "dstreg", curi->size, "dst");
break;
case i_NEG:
@ -993,7 +1017,15 @@ static void gen_opcode (unsigned long int opcode)
printf ("\tif (cflg) newv -= 0x60;\n");
printf ("\tSET_CFLG (cflg);\n");
duplicate_carry();
genflags (flag_zn, curi->size, "newv", "", "");
/* Manual says bits NV are undefined though a real 68040 don't change them */
if (cpu_level >= xBCD_KEEPS_NV_FLAGS) {
if (next_cpu_level < xBCD_KEEPS_NV_FLAGS)
next_cpu_level = xBCD_KEEPS_NV_FLAGS - 1;
genflags (flag_z, curi->size, "newv", "", "");
}
else {
genflags (flag_zn, curi->size, "newv", "", "");
}
genastore ("newv", curi->smode, "srcreg", curi->size, "src");
break;
case i_CLR: