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more accuracy fixes

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git-svn-id: file:///home/notaz/opt/svn/PicoDrive@186 be3aeb3a-fb24-0410-a615-afba39da0efa
This commit is contained in:
notaz 2007-07-07 14:54:33 +00:00
parent 2d0b15bb2c
commit 1c88b865ce
5 changed files with 57 additions and 34 deletions
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62
cpu/Cyclone/OpArith.cpp
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@ -237,7 +237,7 @@ int OpMul(int op)
EaCalc(10,0x0e00,rea, 2);
EaRead(10, 2,rea, 2,0x0e00);
ot(" movs r0,r0,asl #16\n");
ot(" movs r1,r0,asl #16\n");
if (type==0) // div
{
@ -249,20 +249,25 @@ int OpMul(int op)
if (sign)
{
ot(" mov r11,#0 ;@ r11 = 1 or 2 if the result is negative\n");
ot(" orrmi r11,r11,#1\n");
ot(" mov r0,r0,asr #16\n");
ot(" rsbmi r0,r0,#0 ;@ Make r0 positive\n");
ot("\n");
ot(" tst r2,r2\n");
ot(" orrmi r11,r11,#2\n");
ot(" rsbmi r2,r2,#0 ;@ Make r2 positive\n");
ot("\n");
ot(" movs r0,r1,asr #16\n");
ot(" orrmi r11,r11,#1\n");
ot(" rsbmi r0,r0,#0 ;@ Make r0 positive\n");
ot("\n");
ot(";@ detect the nasty 0x80000000 / -1 situation\n");
ot(" mov r3,r2,asr #31\n");
ot(" eors r3,r3,r1,asr #16\n");
ot(" beq wrendofop%.4x\n",op);
}
else
{
ot(" mov r0,r0,lsr #16 ;@ use only 16 bits of divisor\n");
ot(" mov r0,r1,lsr #16 ;@ use only 16 bits of divisor\n");
}
ot("\n");
ot(";@ Divide r2 by r0\n");
ot(" mov r3,#0\n");
ot(" mov r1,r0\n");
@ -299,6 +304,8 @@ int OpMul(int op)
ot(" cmp r3,r1,asr #16 ;@ signed overflow?\n");
ot(" orrne r9,r9,#0x10000000 ;@ set overflow flag\n");
ot(" bne endofop%.4x ;@ overflow!\n",op);
ot("\n");
ot("wrendofop%.4x%s\n",op,ms?"":":");
}
else
{
@ -306,6 +313,7 @@ int OpMul(int op)
ot(" movs r1,r3,lsr #16 ;@ check for overflow condition\n");
ot(" orrne r9,r9,#0x10000000 ;@ set overflow flag\n");
ot(" bne endofop%.4x ;@ overflow!\n",op);
ot("\n");
}
ot(" mov r1,r3,lsl #16 ;@ Clip to 16-bits\n");
@ -319,7 +327,7 @@ int OpMul(int op)
if (type==1)
{
ot(";@ Get 16-bit signs right:\n");
ot(" mov r0,r0,%s #16\n",sign?"asr":"lsr");
ot(" mov r0,r1,%s #16\n",sign?"asr":"lsr");
ot(" mov r2,r2,lsl #16\n");
ot(" mov r2,r2,%s #16\n",sign?"asr":"lsr");
ot("\n");
@ -486,29 +494,31 @@ int OpNbcd(int op)
ot(" mov r0,r0,asl #24\n");
ot(" and r2,r2,#0x20000000\n");
ot(" add r2,r0,r2,lsr #5 ;@ add X\n");
ot(" rsbs r1,r2,#0x9a000000 ;@ do arithmetic\n");
ot(" rsb r11,r2,#0x9a000000 ;@ do arithmetic\n");
ot(" orrmi r9,r9,#0x80000000 ;@ N\n");
ot(" cmp r1,#0x9a000000\n");
ot(" cmp r11,#0x9a000000\n");
ot(" beq finish%.4x\n",op);
ot("\n");
ot(" mvn r3,r9,lsr #3 ;@ Undefined V behavior\n",op);
ot(" and r2,r1,#0x0f000000\n");
ot(" mvn r3,r11,lsr #31 ;@ Undefined V behavior\n",op);
ot(" and r2,r11,#0x0f000000\n");
ot(" cmp r2,#0x0a000000\n");
ot(" andeq r1,r1,#0xf0000000\n");
ot(" addeq r1,r1,#0x10000000\n");
ot(" and r3,r3,r1,lsr #3 ;@ Undefined V behavior part II\n",op);
ot(" tst r1,r1\n");
ot(" orr r9,r9,r3 ;@ save V\n",op);
ot(" andeq r11,r11,#0xf0000000\n");
ot(" addeq r11,r11,#0x10000000\n");
ot(" and r3,r3,r11,lsr #31 ;@ Undefined V behavior part II\n",op);
ot(" movs r1,r11,asr #24\n");
ot(" bicne r9,r9,#0x40000000 ;@ Z\n");
ot(" orr r9,r9,r3,lsl #28 ;@ save V\n",op);
ot(" orr r9,r9,#0x20000000 ;@ C\n");
ot("\n");
EaWrite(10, 1, ea,0,0x3f,1);
EaWrite(10, 1, ea,0,0x3f,0,0);
ot("finish%.4x%s\n",op,ms?"":":");
ot(" tst r11,r11\n");
ot(" orrmi r9,r9,#0x80000000 ;@ N\n");
ot(" str r9,[r7,#0x4c] ;@ Save X\n");
ot("\n");
OpEnd(ea);
@ -541,9 +551,19 @@ int OpAritha(int op)
if(size==2&&(sea<0x10||sea==0x3c)) Cycles+=2;
if(type==1) Cycles=6;
// to handle suba.w (A0)+, A0 properly, must calc reg EA first
EaCalcReadNoSE(type!=1?10:-1,11,dea,2,0x0e00);
EaCalcReadNoSE(-1,0,sea,size,0x003f);
// EA calculation order defines how situations like suba.w (A0)+, A0 get handled.
// different emus act differently in this situation, I couldn't fugure which is right behaviour.
// This is Musashi's behaviour.
if (type == 1)
{
EaCalcReadNoSE(-1,0,sea,size,0x003f);
EaCalcReadNoSE(type!=1?10:-1,11,dea,2,0x0e00);
}
else
{
EaCalcReadNoSE(type!=1?10:-1,11,dea,2,0x0e00);
EaCalcReadNoSE(-1,0,sea,size,0x003f);
}
if (size<2) ot(" mov r0,r0,asl #%d\n\n",size?16:24);
if (size<2) asr=(char *)(size?",asr #16":",asr #24");