11dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project/* e_fmodf.c -- float version of e_fmod.c. 21dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. 31dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 41dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 51dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project/* 61dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * ==================================================== 71dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 81dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 91dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Developed at SunPro, a Sun Microsystems, Inc. business. 101dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Permission to use, copy, modify, and distribute this 111dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * software is freely granted, provided that this notice 121dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * is preserved. 131dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * ==================================================== 141dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 151dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 16a0ee07829a9ba7e99ef68e8c12551301cc797f0fElliott Hughes#include <sys/cdefs.h> 17a0ee07829a9ba7e99ef68e8c12551301cc797f0fElliott Hughes__FBSDID("$FreeBSD$"); 181dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 191dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project/* 201dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * __ieee754_fmodf(x,y) 211dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Return x mod y in exact arithmetic 221dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Method: shift and subtract 231dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 241dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 251dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#include "math.h" 261dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#include "math_private.h" 271dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 281dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Projectstatic const float one = 1.0, Zero[] = {0.0, -0.0,}; 291dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 301dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Projectfloat 311dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project__ieee754_fmodf(float x, float y) 321dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project{ 331dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project int32_t n,hx,hy,hz,ix,iy,sx,i; 341dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 351dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project GET_FLOAT_WORD(hx,x); 361dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project GET_FLOAT_WORD(hy,y); 371dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project sx = hx&0x80000000; /* sign of x */ 381dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project hx ^=sx; /* |x| */ 391dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project hy &= 0x7fffffff; /* |y| */ 401dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 411dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* purge off exception values */ 421dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if(hy==0||(hx>=0x7f800000)|| /* y=0,or x not finite */ 431dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project (hy>0x7f800000)) /* or y is NaN */ 441dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return (x*y)/(x*y); 451dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if(hx<hy) return x; /* |x|<|y| return x */ 461dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if(hx==hy) 471dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return Zero[(u_int32_t)sx>>31]; /* |x|=|y| return x*0*/ 481dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 491dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* determine ix = ilogb(x) */ 501dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if(hx<0x00800000) { /* subnormal x */ 511dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project for (ix = -126,i=(hx<<8); i>0; i<<=1) ix -=1; 521dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } else ix = (hx>>23)-127; 531dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 541dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* determine iy = ilogb(y) */ 551dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if(hy<0x00800000) { /* subnormal y */ 561dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project for (iy = -126,i=(hy<<8); i>=0; i<<=1) iy -=1; 571dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } else iy = (hy>>23)-127; 581dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 591dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* set up {hx,lx}, {hy,ly} and align y to x */ 601dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if(ix >= -126) 611dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project hx = 0x00800000|(0x007fffff&hx); 621dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project else { /* subnormal x, shift x to normal */ 631dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project n = -126-ix; 641dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project hx = hx<<n; 651dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 661dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if(iy >= -126) 671dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project hy = 0x00800000|(0x007fffff&hy); 681dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project else { /* subnormal y, shift y to normal */ 691dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project n = -126-iy; 701dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project hy = hy<<n; 711dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 721dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 731dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* fix point fmod */ 741dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project n = ix - iy; 751dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project while(n--) { 761dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project hz=hx-hy; 771dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if(hz<0){hx = hx+hx;} 781dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project else { 791dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if(hz==0) /* return sign(x)*0 */ 801dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return Zero[(u_int32_t)sx>>31]; 811dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project hx = hz+hz; 821dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 831dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 841dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project hz=hx-hy; 851dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if(hz>=0) {hx=hz;} 861dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 871dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* convert back to floating value and restore the sign */ 881dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if(hx==0) /* return sign(x)*0 */ 891dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return Zero[(u_int32_t)sx>>31]; 901dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project while(hx<0x00800000) { /* normalize x */ 911dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project hx = hx+hx; 921dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project iy -= 1; 931dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 941dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if(iy>= -126) { /* normalize output */ 951dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project hx = ((hx-0x00800000)|((iy+127)<<23)); 961dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project SET_FLOAT_WORD(x,hx|sx); 971dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } else { /* subnormal output */ 981dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project n = -126 - iy; 991dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project hx >>= n; 1001dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project SET_FLOAT_WORD(x,hx|sx); 1011dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project x *= one; /* create necessary signal */ 1021dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 1031dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return x; /* exact output */ 1041dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project} 105