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some more optimizations

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git-svn-id: file:///home/notaz/opt/svn/PicoDrive@179 be3aeb3a-fb24-0410-a615-afba39da0efa
This commit is contained in:
notaz 2007-07-01 14:59:15 +00:00
parent b637c56aad
commit 3a5e6cf847
6 changed files with 66 additions and 52 deletions
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86
cpu/Cyclone/OpBranch.cpp
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@ -287,50 +287,60 @@ int OpDbra(int op)
if (op!=use) { OpUse(op,use); return 0; } // Use existing handler
OpStart(op);
if (cc>=2)
switch (cc)
{
ot(";@ Is the condition true?\n");
if ((cc&~1)==2) ot(" eor r9,r9,#0x20000000 ;@ Invert carry for hi/ls\n");
ot(" msr cpsr_flg,r9 ;@ ARM flags = 68000 flags\n");
if ((cc&~1)==2) ot(" eor r9,r9,#0x20000000\n");
ot(";@ If so, don't dbra\n");
ot(" b%s DbraTrue%.4x\n",Cond[cc],op);
ot("\n");
case 0: // T
case 1: // F
break;
case 2: // hi
ot(" tst r9,#0x60000000 ;@ hi: !C && !Z\n");
ot(" beq DbraTrue%.4x\n\n",op);
break;
case 3: // ls
ot(" tst r9,#0x60000000 ;@ ls: C || Z\n");
ot(" bne DbraTrue%.4x\n\n",op);
break;
default:
ot(";@ Is the condition true?\n");
ot(" msr cpsr_flg,r9 ;@ ARM flags = 68000 flags\n");
ot(";@ If so, don't dbra\n");
ot(" b%s DbraTrue%.4x\n\n",Cond[cc],op);
break;
}
ot(";@ Decrement Dn.w\n");
ot(" and r1,r8,#0x0007\n");
ot(" mov r1,r1,lsl #2\n");
ot(" ldrsh r0,[r7,r1]\n");
ot(" sub r0,r0,#1\n");
ot(" strh r0,[r7,r1]\n");
ot("\n");
if (cc!=0)
{
ot(";@ Decrement Dn.w\n");
ot(" and r1,r8,#0x0007\n");
ot(" mov r1,r1,lsl #2\n");
ot(" ldrsh r0,[r7,r1]\n");
ot(" sub r0,r0,#1\n");
ot(" strh r0,[r7,r1]\n");
ot("\n");
ot(";@ Check if Dn.w is -1\n");
ot(" cmps r0,#-1\n");
ot(" beq DbraMin1%.4x\n",op);
ot("\n");
ot(";@ Check if Dn.w is -1\n");
ot(" cmn r0,#1\n");
ot("\n");
ot(";@ Get Branch offset:\n");
ot(" ldrsh r0,[r4]\n");
ot(" add r4,r4,r0 ;@ r4 = New PC\n");
ot("\n");
Cycles=12-2;
OpEnd();
ot(";@ Get Branch offset:\n");
ot(" ldrnesh r0,[r4]\n");
ot(" addeq r4,r4,#2 ;@ Skip branch offset\n");
ot(" subeq r5,r5,#4 ;@ additional cycles\n");
ot(" addne r4,r4,r0 ;@ r4 = New PC\n");
ot("\n");
Cycles=12-2;
OpEnd();
}
ot(";@ Dn.w is -1:\n");
ot("DbraMin1%.4x%s\n", op, ms?"":":");
ot(" add r4,r4,#2 ;@ Skip branch offset\n");
ot("\n");
Cycles=12+2;
OpEnd();
ot(";@ condition true:\n");
ot("DbraTrue%.4x%s\n", op, ms?"":":");
ot(" add r4,r4,#2 ;@ Skip branch offset\n");
ot("\n");
Cycles=12;
OpEnd();
if (cc==0||cc>=2)
{
ot(";@ condition true:\n");
ot("DbraTrue%.4x%s\n", op, ms?"":":");
ot(" add r4,r4,#2 ;@ Skip branch offset\n");
ot("\n");
Cycles=12;
OpEnd();
}
return 0;
}