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code review and optimizations

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git-svn-id: file:///home/notaz/opt/svn/PicoDrive@180 be3aeb3a-fb24-0410-a615-afba39da0efa
This commit is contained in:
notaz 2007-07-03 19:23:12 +00:00
parent 3a5e6cf847
commit 85a36a57a8
10 changed files with 540 additions and 364 deletions
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78
cpu/Cyclone/Ea.cpp
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@ -100,7 +100,7 @@ static int EaCalcReg(int r,int ea,int mask,int forceor,int shift,int noshift=0)
if (ea>=8) needor=1; // Need to OR to access A0-7
if ((mask>>low)&8) if (ea&8) needor=0; // Ah - no we don't actually need to or, since the bit is high in r8
if (((mask&g_op)>>low)&8) needor=0; // Ah - no we don't actually need to or, since the bit is high in r8
if (forceor) needor=1; // Special case for 0x30-0x38 EAs ;)
@ -121,8 +121,9 @@ static int EaCalcReg(int r,int ea,int mask,int forceor,int shift,int noshift=0)
}
// EaCalc - ARM Register 'a' = Effective Address
// Trashes r0,r2 and r3
// If ea>=0x10, trashes r0,r2 and r3, else nothing
// size values 0, 1, 2 ~ byte, word, long
// mask shows usable bits in r8
int EaCalc(int a,int mask,int ea,int size,int top,int sign_extend)
{
char text[32]="";
@ -151,12 +152,19 @@ int EaCalc(int a,int mask,int ea,int size,int top,int sign_extend)
if ((ea&7)==7 && step<2) step=2; // move.b (a7)+ or -(a7) steps by 2 not 1
EaCalcReg(2,ea,mask,0,0,1);
if(mask)
for (i=mask|0x8000; (i&1)==0; i>>=1) low++; // Find out how high up the EA mask is
lsl=2-low; // Having a lsl #x here saves one opcode
if (lsl>=0) ot(" ldr r%d,[r7,r2,lsl #%i]\n",a,lsl);
else if (lsl<0) ot(" ldr r%d,[r7,r2,lsr #%i]\n",a,-lsl);
if (ea==0x1f||ea==0x27) // A7 handlers are always separate
{
ot(" ldr r%d,[r7,#0x3c] ;@ A7\n",a);
}
else
{
EaCalcReg(2,ea,mask,0,0,1);
if(mask)
for (i=mask|0x8000; (i&1)==0; i>>=1) low++; // Find out how high up the EA mask is
lsl=2-low; // Having a lsl #x here saves one opcode
if (lsl>=0) ot(" ldr r%d,[r7,r2,lsl #%i]\n",a,lsl);
else if (lsl<0) ot(" ldr r%d,[r7,r2,lsr #%i]\n",a,-lsl);
}
if ((ea&0x38)==0x18) // (An)+
{
@ -169,8 +177,15 @@ int EaCalc(int a,int mask,int ea,int size,int top,int sign_extend)
if ((ea&0x38)==0x18||(ea&0x38)==0x20)
{
if (lsl>=0) ot(" str r%d,[r7,r2,lsl #%i]\n",strr,lsl);
else if (lsl<0) ot(" str r%d,[r7,r2,lsr #%i]\n",strr,-lsl);
if (ea==0x1f||ea==0x27)
{
ot(" str r%d,[r7,#0x3c] ;@ A7\n",strr);
}
else
{
if (lsl>=0) ot(" str r%d,[r7,r2,lsl #%i]\n",strr,lsl);
else if (lsl<0) ot(" str r%d,[r7,r2,lsr #%i]\n",strr,-lsl);
}
}
if ((ea&0x38)==0x20) Cycles+=size<2 ? 6:10; // -(An) Extra cycles
@ -263,8 +278,8 @@ int EaCalc(int a,int mask,int ea,int size,int top,int sign_extend)
}
ot(" ldrh r2,[r4],#2 ;@ Fetch immediate value\n");
ot(" ldrh r0,[r4],#2\n"); pc_dirty=1;
ot(" orr r%d,r0,r2,lsl #16\n",a);
ot(" ldrh r3,[r4],#2\n"); pc_dirty=1;
ot(" orr r%d,r3,r2,lsl #16\n",a);
Cycles+=8; // Extra cycles
return 0;
}
@ -298,7 +313,7 @@ int EaRead(int a,int v,int ea,int size,int mask,int top,int sign_extend)
lsl=2-low; // Having a lsl #2 here saves one opcode
}
if (top) nsarm=3;
if (top||!sign_extend) nsarm=3;
ot(";@ EaRead : Read register[r%d] into r%d:\n",a,v);
@ -352,6 +367,43 @@ int EaRead(int a,int v,int ea,int size,int mask,int top,int sign_extend)
ot("\n"); return 0;
}
// calculate EA and read
// if (ea < 0x10) nothing is trashed
// if (ea == 0x3c) r2 and r3 are trashed
// else r0-r3 are trashed
// size values 0, 1, 2 ~ byte, word, long
// r_ea is reg to store ea in (-1 means ea is not needed), r is dst reg
// if sign_extend is 0, non-32bit values will have MS bits undefined
int EaCalcRead(int r_ea,int r,int ea,int size,int mask,int sign_extend)
{
if (ea<0x10)
{
if (r_ea==-1)
{
r_ea=r;
if (!sign_extend) size=2;
}
}
else if (ea==0x3c) // #imm
{
r_ea=r;
}
else
{
if (r_ea==-1) r_ea=0;
}
EaCalc (r_ea,mask,ea,size,0,sign_extend);
EaRead (r_ea, r,ea,size,mask,0,sign_extend);
return 0;
}
int EaCalcReadNoSE(int r_ea,int r,int ea,int size,int mask)
{
return EaCalcRead(r_ea,r,ea,size,mask,0);
}
// Return 1 if we can read this ea
int EaCanRead(int ea,int size)
{