X-Git-Url: https://notaz.gp2x.de/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=cpu%2Fmusashi%2Fm68k_in.c;h=d1756a53d491af71124be284461ee1b712232629;hb=c6e1e9779a5652b58ae638e40f4b01ccb223b0d0;hp=5c9cc0669021d5ce1f648d0913dcdab097b84d76;hpb=f6aa2456a483b54566442d28d18a9f2fb2740125;p=picodrive.git

diff --git a/cpu/musashi/m68k_in.c b/cpu/musashi/m68k_in.c
index 5c9cc06..d1756a5 100644
--- a/cpu/musashi/m68k_in.c
+++ b/cpu/musashi/m68k_in.c
@@ -918,13 +918,15 @@ M68KMAKE_OP(abcd, 8, rr, .)
 	uint src = DY;
 	uint dst = *r_dst;
 	uint res = LOW_NIBBLE(src) + LOW_NIBBLE(dst) + XFLAG_AS_1();
-
-	FLAG_V = ~res; /* Undefined V behavior */
+	uint corf = 0;
 
 	if(res > 9)
-		res += 6;
+		corf = 6;
 	res += HIGH_NIBBLE(src) + HIGH_NIBBLE(dst);
-	FLAG_X = FLAG_C = (res > 0x99) << 8;
+	FLAG_V = ~res; /* Undefined V behavior */
+
+	res += corf;
+	FLAG_X = FLAG_C = (res > 0x9f) << 8;
 	if(FLAG_C)
 		res -= 0xa0;
 
@@ -944,13 +946,15 @@ M68KMAKE_OP(abcd, 8, mm, ax7)
 	uint ea  = EA_A7_PD_8();
 	uint dst = m68ki_read_8(ea);
 	uint res = LOW_NIBBLE(src) + LOW_NIBBLE(dst) + XFLAG_AS_1();
-
-	FLAG_V = ~res; /* Undefined V behavior */
+	uint corf = 0;
 
 	if(res > 9)
-		res += 6;
+		corf = 6;
 	res += HIGH_NIBBLE(src) + HIGH_NIBBLE(dst);
-	FLAG_X = FLAG_C = (res > 0x99) << 8;
+	FLAG_V = ~res; /* Undefined V behavior */
+
+	res += corf;
+	FLAG_X = FLAG_C = (res > 0x9f) << 8;
 	if(FLAG_C)
 		res -= 0xa0;
 
@@ -970,13 +974,15 @@ M68KMAKE_OP(abcd, 8, mm, ay7)
 	uint ea  = EA_AX_PD_8();
 	uint dst = m68ki_read_8(ea);
 	uint res = LOW_NIBBLE(src) + LOW_NIBBLE(dst) + XFLAG_AS_1();
-
-	FLAG_V = ~res; /* Undefined V behavior */
+	uint corf = 0;
 
 	if(res > 9)
-		res += 6;
+		corf = 6;
 	res += HIGH_NIBBLE(src) + HIGH_NIBBLE(dst);
-	FLAG_X = FLAG_C = (res > 0x99) << 8;
+	FLAG_V = ~res; /* Undefined V behavior */
+
+	res += corf;
+	FLAG_X = FLAG_C = (res > 0x9f) << 8;
 	if(FLAG_C)
 		res -= 0xa0;
 
@@ -996,13 +1002,15 @@ M68KMAKE_OP(abcd, 8, mm, axy7)
 	uint ea  = EA_A7_PD_8();
 	uint dst = m68ki_read_8(ea);
 	uint res = LOW_NIBBLE(src) + LOW_NIBBLE(dst) + XFLAG_AS_1();
-
-	FLAG_V = ~res; /* Undefined V behavior */
+	uint corf = 0;
 
 	if(res > 9)
-		res += 6;
+		corf = 6;
 	res += HIGH_NIBBLE(src) + HIGH_NIBBLE(dst);
-	FLAG_X = FLAG_C = (res > 0x99) << 8;
+	FLAG_V = ~res; /* Undefined V behavior */
+
+	res += corf;
+	FLAG_X = FLAG_C = (res > 0x9f) << 8;
 	if(FLAG_C)
 		res -= 0xa0;
 
@@ -1022,13 +1030,15 @@ M68KMAKE_OP(abcd, 8, mm, .)
 	uint ea  = EA_AX_PD_8();
 	uint dst = m68ki_read_8(ea);
 	uint res = LOW_NIBBLE(src) + LOW_NIBBLE(dst) + XFLAG_AS_1();
-
-	FLAG_V = ~res; /* Undefined V behavior */
+	uint corf = 0;
 
 	if(res > 9)
-		res += 6;
+		corf = 6;
 	res += HIGH_NIBBLE(src) + HIGH_NIBBLE(dst);
-	FLAG_X = FLAG_C = (res > 0x99) << 8;
+	FLAG_V = ~res; /* Undefined V behavior */
+
+	res += corf;
+	FLAG_X = FLAG_C = (res > 0x9f) << 8;
 	if(FLAG_C)
 		res -= 0xa0;
 
@@ -7794,19 +7804,19 @@ M68KMAKE_OP(mull, 32, ., .)
 M68KMAKE_OP(nbcd, 8, ., d)
 {
 	uint* r_dst = &DY;
-	uint dst = *r_dst;
-	uint res = MASK_OUT_ABOVE_8(0x9a - dst - XFLAG_AS_1());
+	uint dst = MASK_OUT_ABOVE_8(*r_dst);
+	uint res = -dst - XFLAG_AS_1();
 
-	if(res != 0x9a)
+	if(res != 0)
 	{
-		FLAG_V = ~res; /* Undefined V behavior */
+		FLAG_V = res; /* Undefined V behavior */
 
-		if((res & 0x0f) == 0xa)
-			res = (res & 0xf0) + 0x10;
+		if(((res|dst) & 0x0f) == 0)
+			res = (res & 0xf0) + 6;
 
-		res = MASK_OUT_ABOVE_8(res);
+		res = MASK_OUT_ABOVE_8(res + 0x9a);
 
-		FLAG_V &= res; /* Undefined V behavior part II */
+		FLAG_V &= ~res; /* Undefined V behavior part II */
 
 		*r_dst = MASK_OUT_BELOW_8(*r_dst) | res;
 
@@ -7828,18 +7838,18 @@ M68KMAKE_OP(nbcd, 8, ., .)
 {
 	uint ea = M68KMAKE_GET_EA_AY_8;
 	uint dst = m68ki_read_8(ea);
-	uint res = MASK_OUT_ABOVE_8(0x9a - dst - XFLAG_AS_1());
+	uint res = -dst - XFLAG_AS_1();
 
-	if(res != 0x9a)
+	if(res != 0)
 	{
-		FLAG_V = ~res; /* Undefined V behavior */
+		FLAG_V = res; /* Undefined V behavior */
 
-		if((res & 0x0f) == 0xa)
-			res = (res & 0xf0) + 0x10;
+		if(((res|dst) & 0x0f) == 0)
+			res = (res & 0xf0) + 6;
 
-		res = MASK_OUT_ABOVE_8(res);
+		res = MASK_OUT_ABOVE_8(res + 0x9a);
 
-		FLAG_V &= res; /* Undefined V behavior part II */
+		FLAG_V &= ~res; /* Undefined V behavior part II */
 
 		m68ki_write_8(ea, MASK_OUT_ABOVE_8(res));
 
@@ -9359,26 +9369,26 @@ M68KMAKE_OP(sbcd, 8, rr, .)
 	uint src = DY;
 	uint dst = *r_dst;
 	uint res = LOW_NIBBLE(dst) - LOW_NIBBLE(src) - XFLAG_AS_1();
+	uint corf = 0;
 
-//  FLAG_V = ~res; /* Undefined V behavior */
-	FLAG_V = VFLAG_CLEAR;	/* Undefined in Motorola's M68000PM/AD rev.1 and safer to assume cleared. */
-
-	if(res > 9)
-		res -= 6;
+	if(res > 0xf)
+		corf = 6;
 	res += HIGH_NIBBLE(dst) - HIGH_NIBBLE(src);
-	if(res > 0x99)
+	FLAG_V = res; /* Undefined V behavior */
+	if(res > 0xff)
 	{
 		res += 0xa0;
 		FLAG_X = FLAG_C = CFLAG_SET;
-		FLAG_N = NFLAG_SET;	/* Undefined in Motorola's M68000PM/AD rev.1 and safer to follow carry. */
 	}
+	else if(res < corf)
+		FLAG_X = FLAG_C = CFLAG_SET;
 	else
-		FLAG_N = FLAG_X = FLAG_C = 0;
+		FLAG_X = FLAG_C = 0;
 
-	res = MASK_OUT_ABOVE_8(res);
+	res = MASK_OUT_ABOVE_8(res - corf);
 
-//  FLAG_V &= res; /* Undefined V behavior part II */
-//  FLAG_N = NFLAG_8(res); /* Undefined N behavior */
+	FLAG_V &= ~res; /* Undefined V behavior part II */
+	FLAG_N = NFLAG_8(res); /* Undefined N behavior */
 	FLAG_Z |= res;
 
 	*r_dst = MASK_OUT_BELOW_8(*r_dst) | res;
@@ -9391,26 +9401,26 @@ M68KMAKE_OP(sbcd, 8, mm, ax7)
 	uint ea  = EA_A7_PD_8();
 	uint dst = m68ki_read_8(ea);
 	uint res = LOW_NIBBLE(dst) - LOW_NIBBLE(src) - XFLAG_AS_1();
+	uint corf = 0;
 
-//  FLAG_V = ~res; /* Undefined V behavior */
-	FLAG_V = VFLAG_CLEAR;	/* Undefined in Motorola's M68000PM/AD rev.1 and safer to return zero. */
-
-	if(res > 9)
-		res -= 6;
+	if(res > 0xf)
+		corf = 6;
 	res += HIGH_NIBBLE(dst) - HIGH_NIBBLE(src);
-	if(res > 0x99)
+	FLAG_V = res; /* Undefined V behavior */
+	if(res > 0xff)
 	{
 		res += 0xa0;
 		FLAG_X = FLAG_C = CFLAG_SET;
-		FLAG_N = NFLAG_SET;	/* Undefined in Motorola's M68000PM/AD rev.1 and safer to follow carry. */
 	}
+	else if(res < corf)
+		FLAG_X = FLAG_C = CFLAG_SET;
 	else
-		FLAG_N = FLAG_X = FLAG_C = 0;
+		FLAG_X = FLAG_C = 0;
 
-	res = MASK_OUT_ABOVE_8(res);
+	res = MASK_OUT_ABOVE_8(res - corf);
 
-//  FLAG_V &= res; /* Undefined V behavior part II */
-//  FLAG_N = NFLAG_8(res); /* Undefined N behavior */
+	FLAG_V &= ~res; /* Undefined V behavior part II */
+	FLAG_N = NFLAG_8(res); /* Undefined N behavior */
 	FLAG_Z |= res;
 
 	m68ki_write_8(ea, res);
@@ -9423,26 +9433,26 @@ M68KMAKE_OP(sbcd, 8, mm, ay7)
 	uint ea  = EA_AX_PD_8();
 	uint dst = m68ki_read_8(ea);
 	uint res = LOW_NIBBLE(dst) - LOW_NIBBLE(src) - XFLAG_AS_1();
+	uint corf = 0;
 
-//  FLAG_V = ~res; /* Undefined V behavior */
-	FLAG_V = VFLAG_CLEAR;	/* Undefined in Motorola's M68000PM/AD rev.1 and safer to return zero. */
-
-	if(res > 9)
-		res -= 6;
+	if(res > 0xf)
+		corf = 6;
 	res += HIGH_NIBBLE(dst) - HIGH_NIBBLE(src);
-	if(res > 0x99)
+	FLAG_V = res; /* Undefined V behavior */
+	if(res > 0xff)
 	{
 		res += 0xa0;
 		FLAG_X = FLAG_C = CFLAG_SET;
-		FLAG_N = NFLAG_SET;	/* Undefined in Motorola's M68000PM/AD rev.1 and safer to follow carry. */
 	}
+	else if(res < corf)
+		FLAG_X = FLAG_C = CFLAG_SET;
 	else
-		FLAG_N = FLAG_X = FLAG_C = 0;
+		FLAG_X = FLAG_C = 0;
 
-	res = MASK_OUT_ABOVE_8(res);
+	res = MASK_OUT_ABOVE_8(res - corf);
 
-//  FLAG_V &= res; /* Undefined V behavior part II */
-//  FLAG_N = NFLAG_8(res); /* Undefined N behavior */
+	FLAG_V &= ~res; /* Undefined V behavior part II */
+	FLAG_N = NFLAG_8(res); /* Undefined N behavior */
 	FLAG_Z |= res;
 
 	m68ki_write_8(ea, res);
@@ -9455,26 +9465,26 @@ M68KMAKE_OP(sbcd, 8, mm, axy7)
 	uint ea  = EA_A7_PD_8();
 	uint dst = m68ki_read_8(ea);
 	uint res = LOW_NIBBLE(dst) - LOW_NIBBLE(src) - XFLAG_AS_1();
+	uint corf = 0;
 
-//  FLAG_V = ~res; /* Undefined V behavior */
-	FLAG_V = VFLAG_CLEAR;	/* Undefined in Motorola's M68000PM/AD rev.1 and safer to return zero. */
-
-	if(res > 9)
-		res -= 6;
+	if(res > 0xf)
+		corf = 6;
 	res += HIGH_NIBBLE(dst) - HIGH_NIBBLE(src);
-	if(res > 0x99)
+	FLAG_V = res; /* Undefined V behavior */
+	if(res > 0xff)
 	{
 		res += 0xa0;
 		FLAG_X = FLAG_C = CFLAG_SET;
-		FLAG_N = NFLAG_SET;	/* Undefined in Motorola's M68000PM/AD rev.1 and safer to follow carry. */
 	}
+	else if(res < corf)
+		FLAG_X = FLAG_C = CFLAG_SET;
 	else
-		FLAG_N = FLAG_X = FLAG_C = 0;
+		FLAG_X = FLAG_C = 0;
 
-	res = MASK_OUT_ABOVE_8(res);
+	res = MASK_OUT_ABOVE_8(res - corf);
 
-//  FLAG_V &= res; /* Undefined V behavior part II */
-//  FLAG_N = NFLAG_8(res); /* Undefined N behavior */
+	FLAG_V &= ~res; /* Undefined V behavior part II */
+	FLAG_N = NFLAG_8(res); /* Undefined N behavior */
 	FLAG_Z |= res;
 
 	m68ki_write_8(ea, res);
@@ -9487,26 +9497,26 @@ M68KMAKE_OP(sbcd, 8, mm, .)
 	uint ea  = EA_AX_PD_8();
 	uint dst = m68ki_read_8(ea);
 	uint res = LOW_NIBBLE(dst) - LOW_NIBBLE(src) - XFLAG_AS_1();
+	uint corf = 0;
 
-//  FLAG_V = ~res; /* Undefined V behavior */
-	FLAG_V = VFLAG_CLEAR;	/* Undefined in Motorola's M68000PM/AD rev.1 and safer to return zero. */
-
-	if(res > 9)
-		res -= 6;
+	if(res > 0xf)
+		corf = 6;
 	res += HIGH_NIBBLE(dst) - HIGH_NIBBLE(src);
-	if(res > 0x99)
+	FLAG_V = res; /* Undefined V behavior */
+	if(res > 0xff)
 	{
 		res += 0xa0;
 		FLAG_X = FLAG_C = CFLAG_SET;
-		FLAG_N = NFLAG_SET;	/* Undefined in Motorola's M68000PM/AD rev.1 and safer to follow carry. */
 	}
+	else if(res < corf)
+		FLAG_X = FLAG_C = CFLAG_SET;
 	else
-		FLAG_N = FLAG_X = FLAG_C = 0;
+		FLAG_X = FLAG_C = 0;
 
-	res = MASK_OUT_ABOVE_8(res);
+	res = MASK_OUT_ABOVE_8(res - corf);
 
-//  FLAG_V &= res; /* Undefined V behavior part II */
-//  FLAG_N = NFLAG_8(res); /* Undefined N behavior */
+	FLAG_V &= ~res; /* Undefined V behavior part II */
+	FLAG_N = NFLAG_8(res); /* Undefined N behavior */
 	FLAG_Z |= res;
 
 	m68ki_write_8(ea, res);