EIC code displayed by LXR master/​include/​vdt/​vdtcore_common.h	Source navigation Diff markup Identifier search General search
	Version: master test Revert   Change

File indexing completed on 2025-02-21 10:16:43

 /*
  * vdtcore_common.h
  * Common functions for the vdt routines.
  * The basic idea is to exploit Pade polynomials.
  * A lot of ideas were inspired by the cephes math library (by Stephen L. Moshier
  * moshier@na-net.ornl.gov) as well as actual code for the exp, log, sin, cos, 
  * tan, asin, acos and atan functions. The Cephes library can be found here:
  * http://www.netlib.org/cephes/
  * 
  *  Created on: Jun 23, 2012
  *      Author: Danilo Piparo, Thomas Hauth, Vincenzo Innocente
  */
 
 /* 
  * VDT is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser Public License as published by
  * the Free Software Foundation, either version 3 of the License, or
  * (at your option) any later version.
  * 
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU Lesser Public License for more details.
  * 
  * You should have received a copy of the GNU Lesser Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 #ifndef VDTCOMMON_H_
 #define VDTCOMMON_H_
 
 #include "inttypes.h"
 #include <cmath>
 
 namespace vdt{
 
 namespace details{
 
 // Constants
 const double TWOPI = 2.*M_PI;
 const double PI = M_PI;
 const double PIO2 = M_PI_2;
 const double PIO4 = M_PI_4;
 const double ONEOPIO4 = 4./M_PI;
 
 const float TWOPIF = 2.*M_PI;
 const float PIF = M_PI;
 const float PIO2F = M_PI_2;
 const float PIO4F = M_PI_4;
 const float ONEOPIO4F = 4./M_PI;
 
 const double MOREBITS = 6.123233995736765886130E-17;
 
 
 const float MAXNUMF = 3.4028234663852885981170418348451692544e38f;
 
 //------------------------------------------------------------------------------
 
 /// Used to switch between different type of interpretations of the data (64 bits)
 union ieee754{
     inline ieee754 () {};
     inline ieee754 (double thed) {d=thed;};
     inline ieee754 (uint64_t thell) {ll=thell;};
     inline ieee754 (float thef) {f[0]=thef;};
     inline ieee754 (uint32_t thei) {i[0]=thei;};
   double d;
   float f[2];
   uint32_t i[2];
   uint64_t ll;
   uint16_t s[4];
 };
 
 //------------------------------------------------------------------------------
 
 /// Converts an unsigned long long to a double
 inline double uint642dp(uint64_t ll) {
   ieee754 tmp;
   tmp.ll=ll;
   return tmp.d;
 }
 
 //------------------------------------------------------------------------------
 
 /// Converts a double to an unsigned long long
 inline uint64_t dp2uint64(double x) {
   ieee754 tmp;
   tmp.d=x;
   return tmp.ll;
 }
 
 //------------------------------------------------------------------------------
 /// Makes an AND of a double and a unsigned long long
 inline double dpANDuint64(const double x, const uint64_t i ){
   return uint642dp(dp2uint64(x) & i); 
 }
 //------------------------------------------------------------------------------
 /// Makes an OR of a double and a unsigned long long
 inline double dpORuint64(const double x, const uint64_t i ){
   return uint642dp(dp2uint64(x) | i); 
 }
 
 /// Makes a XOR of a double and a unsigned long long
 inline double dpXORuint64(const double x, const uint64_t i ){
   return uint642dp(dp2uint64(x) ^ i); 
 }
 
 //------------------------------------------------------------------------------
 inline uint64_t getSignMask(const double x){
   const uint64_t mask=0x8000000000000000ULL;
   return dp2uint64(x) & mask;
 }
 
 //------------------------------------------------------------------------------
 /// Converts an int to a float
 inline float uint322sp(int x) {
     ieee754 tmp;
     tmp.i[0]=x;
     return tmp.f[0];
   }
 
 //------------------------------------------------------------------------------
 /// Converts a float to an int
 inline uint32_t sp2uint32(float x) {
     ieee754 tmp;
     tmp.f[0]=x;
     return tmp.i[0];
   }
 
 //------------------------------------------------------------------------------
 /// Makes an AND of a float and a unsigned long
 inline float spANDuint32(const float x, const uint32_t i ){
   return uint322sp(sp2uint32(x) & i); 
 }
 //------------------------------------------------------------------------------
 /// Makes an OR of a float and a unsigned long
 inline float spORuint32(const float x, const uint32_t i ){
   return uint322sp(sp2uint32(x) | i); 
 }
 
 //------------------------------------------------------------------------------
 /// Makes an OR of a float and a unsigned long
 inline float spXORuint32(const float x, const uint32_t i ){
   return uint322sp(sp2uint32(x) ^ i); 
 }
 //------------------------------------------------------------------------------
 /// Get the sign mask
 inline uint32_t getSignMask(const float x){
   const uint32_t mask=0x80000000;
   return sp2uint32(x) & mask;
 }
 
 //------------------------------------------------------------------------------
 /// Like frexp but vectorising and the exponent is a double.
 inline double getMantExponent(const double x, double & fe){
 
   uint64_t n = dp2uint64(x);
 
   // Shift to the right up to the beginning of the exponent.
   // Then with a mask, cut off the sign bit
   uint64_t le = (n >> 52);
 
   // chop the head of the number: an int contains more than 11 bits (32)
   int32_t e = le; // This is important since sums on uint64_t do not vectorise
   fe = e-1023 ;
 
   // This puts to 11 zeroes the exponent
   n &=0x800FFFFFFFFFFFFFULL;
   // build a mask which is 0.5, i.e. an exponent equal to 1022
   // which means *2, see the above +1.
   const uint64_t p05 = 0x3FE0000000000000ULL; //dp2uint64(0.5);
   n |= p05;
 
   return uint642dp(n);
 }
 
 //------------------------------------------------------------------------------
 /// Like frexp but vectorising and the exponent is a float.
 inline float getMantExponentf(const float x, float & fe){
 
     uint32_t n = sp2uint32(x);
     int32_t e = (n >> 23)-127;
     fe = e;
 
     // fractional part
     const uint32_t p05f = 0x3f000000; // //sp2uint32(0.5);
     n &= 0x807fffff;// ~0x7f800000;
     n |= p05f;
 
     return uint322sp(n);
 
 }
 
 //------------------------------------------------------------------------------
 /// Converts a fp to an int
 inline uint32_t fp2uint(float x) {
     return sp2uint32(x);
   }
 /// Converts a fp to an int
 inline uint64_t fp2uint(double x) {
     return dp2uint64(x);
   }
 /// Converts an int to fp
 inline float int2fp(uint32_t i) {
     return uint322sp(i);
   }
 /// Converts an int to fp
 inline double int2fp(uint64_t i) {
     return uint642dp(i);
   }
 
 //------------------------------------------------------------------------------
 /**
  * A vectorisable floor implementation, not only triggered by fast-math.
  * These functions do not distinguish between -0.0 and 0.0, so are not IEC6509 
  * compliant for argument -0.0
 **/ 
 inline double fpfloor(const double x){
   // no problem since exp is defined between -708 and 708. Int is enough for it!
   int32_t ret = int32_t (x);
   ret-=(sp2uint32(x)>>31);  
   return ret;
 
 }
 //------------------------------------------------------------------------------
 /**
  * A vectorisable floor implementation, not only triggered by fast-math.
  * These functions do not distinguish between -0.0 and 0.0, so are not IEC6509 
  * compliant for argument -0.0
 **/ 
 inline float fpfloor(const float x){
   int32_t ret = int32_t (x);
   ret-=(sp2uint32(x)>>31);  
   return ret;
 
 }
 
 //------------------------------------------------------------------------------
 
 
 
 
 }
 
 } // end of namespace vdt
 
 #endif /* VDTCOMMON_H_ */

This page was automatically generated by the 2.3.7 LXR engine. The LXR team