Merge pull request #2586 from Tilka/interpreter_nans

Interpreter: optimize NaN checks
This commit is contained in:
flacs 2015-06-10 15:30:48 +02:00
commit 6bc85995bd
1 changed files with 27 additions and 21 deletions

View File

@ -4,6 +4,7 @@
#pragma once
#include <cmath>
#include <limits>
#include "Common/CPUDetect.h"
@ -83,11 +84,11 @@ 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 (std::isnan(t))
{
if (std::isnan(a)) return a;
if (std::isnan(b)) return b;
SetFPException(FPSCR_VXIMZ);
return PPC_NAN;
}
@ -96,11 +97,11 @@ 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 (std::isnan(t))
{
if (std::isnan(a)) return a;
if (std::isnan(b)) return b;
SetFPException(FPSCR_VXISI);
return PPC_NAN;
}
@ -109,31 +110,35 @@ 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 (std::isnan(t))
{
if (std::isnan(a)) return a;
if (std::isnan(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 (std::isnan(t))
{
if (std::isnan(a)) return a;
if (std::isnan(b)) return b; // !
if (std::isnan(c)) return c;
SetFPException(FPSCR_VXIMZ);
return PPC_NAN;
}
t = t + b;
if (t != t)
t += b;
if (std::isnan(t))
{
if (std::isnan(b)) return b;
SetFPException(FPSCR_VXISI);
return PPC_NAN;
}
@ -142,19 +147,20 @@ 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 (std::isnan(t))
{
if (std::isnan(a)) return a;
if (std::isnan(b)) return b; // !
if (std::isnan(c)) return c;
SetFPException(FPSCR_VXIMZ);
return PPC_NAN;
}
t = t - b;
if (t != t)
t -= b;
if (std::isnan(t))
{
if (std::isnan(b)) return b;
SetFPException(FPSCR_VXISI);
return PPC_NAN;
}