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Interpreter: optimize NaN checks

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NaNs always propagate, so we can get away with only checking for NaN
inputs in the rare case that the result is NaN (as already done in
Jit64::HandleNaNs()).
This commit is contained in:
Tillmann Karras 2015-06-10 14:23:43 +02:00
parent 9b8eb55cd4
commit c7544719e2
1 changed files with 17 additions and 12 deletions
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29
Source/Core/Core/PowerPC/Interpreter/Interpreter_FPUtils.h
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@ -83,11 +83,11 @@ inline double Force25Bit(double d)
inline double NI_mul(double a, double b)
{
if (a != a) return a;
if (b != b) return b;
double t = a * b;
if (t != t)
{
if (a != a) return a;
if (b != b) return b;
SetFPException(FPSCR_VXIMZ);
return PPC_NAN;
}
@ -96,11 +96,11 @@ inline double NI_mul(double a, double b)
inline double NI_add(double a, double b)
{
if (a != a) return a;
if (b != b) return b;
double t = a + b;
if (t != t)
{
if (a != a) return a;
if (b != b) return b;
SetFPException(FPSCR_VXISI);
return PPC_NAN;
}
@ -109,31 +109,35 @@ inline double NI_add(double a, double b)
inline double NI_sub(double a, double b)
{
if (a != a) return a;
if (b != b) return b;
double t = a - b;
if (t != t)
{
if (a != a) return a;
if (b != b) return b;
SetFPException(FPSCR_VXISI);
return PPC_NAN;
}
return t;
}
// FMA instructions on PowerPC are weird:
// They calculate (a * c) + b, but the order in which
// inputs are checked for NaN is still a, b, c.
inline double NI_madd(double a, double c, double b, bool negate = false)
{
if (a != a) return a;
if (b != b) return b;
if (c != c) return c;
double t = a * c;
if (t != t)
{
if (a != a) return a;
if (b != b) return b; // !
if (c != c) return c;
SetFPException(FPSCR_VXIMZ);
return PPC_NAN;
}
t = t + b;
if (t != t)
{
if (b != b) return b;
SetFPException(FPSCR_VXISI);
return PPC_NAN;
}
@ -142,12 +146,12 @@ inline double NI_madd(double a, double c, double b, bool negate = false)
inline double NI_msub(double a, double c, double b, bool negate = false)
{
if (a != a) return a;
if (b != b) return b;
if (c != c) return c;
double t = a * c;
if (t != t)
{
if (a != a) return a;
if (b != b) return b; // !
if (c != c) return c;
SetFPException(FPSCR_VXIMZ);
return PPC_NAN;
}
@ -155,6 +159,7 @@ inline double NI_msub(double a, double c, double b, bool negate = false)
t = t - b;
if (t != t)
{
if (b != b) return b;
SetFPException(FPSCR_VXISI);
return PPC_NAN;
}