piwalker/dolphin
1
0
Fork 0
mirror of https://github.com/dolphin-emu/dolphin.git synced 2024-11-14 21:37:52 -07:00
Code Issues Actions Packages Projects Releases Wiki Activity

Interpreter_Integer: Handle OE bit for subf, subfc, subfe, subfme, and subfze

Browse Source 
With this, overflow flag support is now fully implemented for all
instructions that support it.
This commit is contained in:
Lioncash 2018-03-22 10:49:04 -04:00
parent 59c5bc964f
commit 796d67e1ec
1 changed files with 41 additions and 28 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

69
Source/Core/Core/PowerPC/Interpreter/Interpreter_Integer.cpp
View File

@ -612,70 +612,83 @@ void Interpreter::negx(UGeckoInstruction inst)
void Interpreter::subfx(UGeckoInstruction inst)
{
rGPR[inst.RD] = rGPR[inst.RB] - rGPR[inst.RA];
const u32 a = ~rGPR[inst.RA];
const u32 b = rGPR[inst.RB];
const u32 result = a + b + 1;
rGPR[inst.RD] = result;
if (inst.OE)
PanicAlert("OE: subfx");
SetXER_OV(HasAddOverflowed(a, b, result));
if (inst.Rc)
Helper_UpdateCR0(rGPR[inst.RD]);
Helper_UpdateCR0(result);
}
void Interpreter::subfcx(UGeckoInstruction inst)
{
u32 a = rGPR[inst.RA];
u32 b = rGPR[inst.RB];
rGPR[inst.RD] = b - a;
SetCarry(a == 0 || Helper_Carry(b, 0 - a));
const u32 a = ~rGPR[inst.RA];
const u32 b = rGPR[inst.RB];
const u32 result = a + b + 1;
rGPR[inst.RD] = result;
SetCarry(a == 0xFFFFFFFF || Helper_Carry(b, a + 1));
if (inst.OE)
PanicAlert("OE: subfcx");
SetXER_OV(HasAddOverflowed(a, b, result));
if (inst.Rc)
Helper_UpdateCR0(rGPR[inst.RD]);
Helper_UpdateCR0(result);
}
void Interpreter::subfex(UGeckoInstruction inst)
{
u32 a = rGPR[inst.RA];
u32 b = rGPR[inst.RB];
int carry = GetCarry();
rGPR[inst.RD] = (~a) + b + carry;
SetCarry(Helper_Carry(~a, b) || Helper_Carry((~a) + b, carry));
const u32 a = ~rGPR[inst.RA];
const u32 b = rGPR[inst.RB];
const u32 carry = GetCarry();
const u32 result = a + b + carry;
rGPR[inst.RD] = result;
SetCarry(Helper_Carry(a, b) || Helper_Carry(a + b, carry));
if (inst.OE)
PanicAlert("OE: subfex");
SetXER_OV(HasAddOverflowed(a, b, result));
if (inst.Rc)
Helper_UpdateCR0(rGPR[inst.RD]);
Helper_UpdateCR0(result);
}
// sub from minus one
void Interpreter::subfmex(UGeckoInstruction inst)
{
u32 a = rGPR[inst.RA];
int carry = GetCarry();
rGPR[inst.RD] = (~a) + carry - 1;
SetCarry(Helper_Carry(~a, carry - 1));
const u32 a = ~rGPR[inst.RA];
const u32 b = 0xFFFFFFFF;
const u32 carry = GetCarry();
const u32 result = a + b + carry;
rGPR[inst.RD] = result;
SetCarry(Helper_Carry(a, carry - 1));
if (inst.OE)
PanicAlert("OE: subfmex");
SetXER_OV(HasAddOverflowed(a, b, result));
if (inst.Rc)
Helper_UpdateCR0(rGPR[inst.RD]);
Helper_UpdateCR0(result);
}
// sub from zero
void Interpreter::subfzex(UGeckoInstruction inst)
{
u32 a = rGPR[inst.RA];
int carry = GetCarry();
rGPR[inst.RD] = (~a) + carry;
SetCarry(Helper_Carry(~a, carry));
const u32 a = ~rGPR[inst.RA];
const u32 carry = GetCarry();
const u32 result = a + carry;
rGPR[inst.RD] = result;
SetCarry(Helper_Carry(a, carry));
if (inst.OE)
PanicAlert("OE: subfzex");
SetXER_OV(HasAddOverflowed(a, 0, result));
if (inst.Rc)
Helper_UpdateCR0(rGPR[inst.RD]);
Helper_UpdateCR0(result);
}