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Merge pull request #2586 from Tilka/interpreter_nans

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Interpreter: optimize NaN checks
This commit is contained in:
flacs
2015-06-10 15:30:48 +02:00
parent 9b8eb55cd4 d329147871
commit 6bc85995bd
1 changed files with 27 additions and 21 deletions
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48
Source/Core/Core/PowerPC/Interpreter/Interpreter_FPUtils.h
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@ -4,6 +4,7 @@
#pragma once #pragma once
#include <cmath>
#include <limits> #include <limits>
#include "Common/CPUDetect.h" #include "Common/CPUDetect.h"
@ -83,11 +84,11 @@ inline double Force25Bit(double d)
inline double NI_mul(double a, double b) inline double NI_mul(double a, double b)
{ {
if (a != a) return a;
if (b != b) return b;
double t = a * 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); SetFPException(FPSCR_VXIMZ);
return PPC_NAN; return PPC_NAN;
} }
@ -96,11 +97,11 @@ inline double NI_mul(double a, double b)
inline double NI_add(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; 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); SetFPException(FPSCR_VXISI);
return PPC_NAN; return PPC_NAN;
} }
@ -109,31 +110,35 @@ inline double NI_add(double a, double b)
inline double NI_sub(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; 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); SetFPException(FPSCR_VXISI);
return PPC_NAN; return PPC_NAN;
} }
return t; 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) 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; 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); SetFPException(FPSCR_VXIMZ);
return PPC_NAN; return PPC_NAN;
} }
t = t + b; t += b;
if (t != t) if (std::isnan(t))
{ {
if (std::isnan(b)) return b;
SetFPException(FPSCR_VXISI); SetFPException(FPSCR_VXISI);
return PPC_NAN; 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) 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; 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); SetFPException(FPSCR_VXIMZ);
return PPC_NAN; return PPC_NAN;
} }
t = t - b; t -= b;
if (t != t) if (std::isnan(t))
{ {
if (std::isnan(b)) return b;
SetFPException(FPSCR_VXISI); SetFPException(FPSCR_VXISI);
return PPC_NAN; return PPC_NAN;
} }