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lib: Add lib and libm, moving current files from stmhal.
Top-level lib directory is for standard C libraries that we want to provide our own versions of (for efficiency and stand-alone reasons). It currently has libm in it for math functions. Also add atanf and atan2f, which addresses issue adafruit#837.
1 parent 17ae239 commit 8707ea3

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Lines changed: 250 additions & 57 deletions

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‎lib/libm/atan2f.c‎

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/*****************************************************************************/
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/*****************************************************************************/
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// atan2f from musl-0.9.15
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/*****************************************************************************/
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/*****************************************************************************/
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/* origin: FreeBSD /usr/src/lib/msun/src/e_atan2f.c */
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/*
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* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
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*/
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunPro, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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#include "libm.h"
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static const float
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pi = 3.1415927410e+00, /* 0x40490fdb */
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pi_lo = -8.7422776573e-08; /* 0xb3bbbd2e */
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float atan2f(float y, float x)
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{
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float z;
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uint32_t m,ix,iy;
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if (isnan(x) || isnan(y))
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return x+y;
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GET_FLOAT_WORD(ix, x);
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GET_FLOAT_WORD(iy, y);
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if (ix == 0x3f800000) /* x=1.0 */
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return atanf(y);
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m = ((iy>>31)&1) | ((ix>>30)&2); /* 2*sign(x)+sign(y) */
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ix &= 0x7fffffff;
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iy &= 0x7fffffff;
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/* when y = 0 */
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if (iy == 0) {
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switch (m) {
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case 0:
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case 1: return y; /* atan(+-0,+anything)=+-0 */
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case 2: return pi; /* atan(+0,-anything) = pi */
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case 3: return -pi; /* atan(-0,-anything) =-pi */
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}
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}
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/* when x = 0 */
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if (ix == 0)
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return m&1 ? -pi/2 : pi/2;
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/* when x is INF */
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if (ix == 0x7f800000) {
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if (iy == 0x7f800000) {
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switch (m) {
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case 0: return pi/4; /* atan(+INF,+INF) */
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case 1: return -pi/4; /* atan(-INF,+INF) */
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case 2: return 3*pi/4; /*atan(+INF,-INF)*/
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case 3: return -3*pi/4; /*atan(-INF,-INF)*/
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}
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} else {
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switch (m) {
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case 0: return 0.0f; /* atan(+...,+INF) */
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case 1: return -0.0f; /* atan(-...,+INF) */
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case 2: return pi; /* atan(+...,-INF) */
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case 3: return -pi; /* atan(-...,-INF) */
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}
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}
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}
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/* |y/x| > 0x1p26 */
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if (ix+(26<<23) < iy || iy == 0x7f800000)
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return m&1 ? -pi/2 : pi/2;
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/* z = atan(|y/x|) with correct underflow */
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if ((m&2) && iy+(26<<23) < ix) /*|y/x| < 0x1p-26, x < 0 */
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z = 0.0;
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else
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z = atanf(fabsf(y/x));
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switch (m) {
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case 0: return z; /* atan(+,+) */
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case 1: return -z; /* atan(-,+) */
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case 2: return pi - (z-pi_lo); /* atan(+,-) */
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default: /* case 3 */
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return (z-pi_lo) - pi; /* atan(-,-) */
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}
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}

‎lib/libm/atanf.c‎

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/*****************************************************************************/
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/*****************************************************************************/
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// atanf from musl-0.9.15
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/*****************************************************************************/
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/*****************************************************************************/
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/* origin: FreeBSD /usr/src/lib/msun/src/s_atanf.c */
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/*
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* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
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*/
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunPro, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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#include "libm.h"
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static const float atanhi[] = {
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4.6364760399e-01, /* atan(0.5)hi 0x3eed6338 */
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7.8539812565e-01, /* atan(1.0)hi 0x3f490fda */
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9.8279368877e-01, /* atan(1.5)hi 0x3f7b985e */
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1.5707962513e+00, /* atan(inf)hi 0x3fc90fda */
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};
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static const float atanlo[] = {
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5.0121582440e-09, /* atan(0.5)lo 0x31ac3769 */
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3.7748947079e-08, /* atan(1.0)lo 0x33222168 */
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3.4473217170e-08, /* atan(1.5)lo 0x33140fb4 */
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7.5497894159e-08, /* atan(inf)lo 0x33a22168 */
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};
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static const float aT[] = {
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3.3333328366e-01,
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-1.9999158382e-01,
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1.4253635705e-01,
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-1.0648017377e-01,
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6.1687607318e-02,
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};
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float atanf(float x)
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{
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float_t w,s1,s2,z;
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uint32_t ix,sign;
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int id;
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GET_FLOAT_WORD(ix, x);
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sign = ix>>31;
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ix &= 0x7fffffff;
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if (ix >= 0x4c800000) { /* if |x| >= 2**26 */
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if (isnan(x))
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return x;
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z = atanhi[3] + 0x1p-120f;
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return sign ? -z : z;
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}
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if (ix < 0x3ee00000) { /* |x| < 0.4375 */
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if (ix < 0x39800000) { /* |x| < 2**-12 */
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if (ix < 0x00800000)
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/* raise underflow for subnormal x */
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FORCE_EVAL(x*x);
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return x;
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}
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id = -1;
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} else {
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x = fabsf(x);
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if (ix < 0x3f980000) { /* |x| < 1.1875 */
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if (ix < 0x3f300000) { /* 7/16 <= |x| < 11/16 */
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id = 0;
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x = (2.0f*x - 1.0f)/(2.0f + x);
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} else { /* 11/16 <= |x| < 19/16 */
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id = 1;
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x = (x - 1.0f)/(x + 1.0f);
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}
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} else {
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if (ix < 0x401c0000) { /* |x| < 2.4375 */
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id = 2;
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x = (x - 1.5f)/(1.0f + 1.5f*x);
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} else { /* 2.4375 <= |x| < 2**26 */
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id = 3;
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x = -1.0f/x;
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}
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}
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}
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/* end of argument reduction */
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z = x*x;
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w = z*z;
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/* break sum from i=0 to 10 aT[i]z**(i+1) into odd and even poly */
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s1 = z*(aT[0]+w*(aT[2]+w*aT[4]));
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s2 = w*(aT[1]+w*aT[3]);
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if (id < 0)
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return x - x*(s1+s2);
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z = atanhi[id] - ((x*(s1+s2) - atanlo[id]) - x);
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return sign ? -z : z;
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}

‎lib/libm/libm.h‎

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/*****************************************************************************/
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/*****************************************************************************/
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// portions extracted from musl-0.9.15 libm.h
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/*****************************************************************************/
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/*****************************************************************************/
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/* origin: FreeBSD /usr/src/lib/msun/src/math_private.h */
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunPro, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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#include <stdint.h>
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#include <math.h>
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#define FORCE_EVAL(x) do { \
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if (sizeof(x) == sizeof(float)) { \
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volatile float __x; \
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__x = (x); \
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(void)__x; \
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} else if (sizeof(x) == sizeof(double)) { \
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volatile double __x; \
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__x = (x); \
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(void)__x; \
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} else { \
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volatile long double __x; \
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__x = (x); \
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(void)__x; \
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} \
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} while(0)
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/* Get a 32 bit int from a float. */
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#define GET_FLOAT_WORD(w,d) \
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do { \
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union {float f; uint32_t i;} __u; \
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__u.f = (d); \
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(w) = __u.i; \
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} while (0)
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/* Set a float from a 32 bit int. */
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#define SET_FLOAT_WORD(d,w) \
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do { \
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union {float f; uint32_t i;} __u; \
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__u.i = (w); \
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(d) = __u.f; \
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} while (0)

stmhal/math.c renamed to lib/libm/math.c

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* THE SOFTWARE.
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*/
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27-
#include <stdint.h>
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#include <math.h>
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#include "libm.h"
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typedef float float_t;
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typedef union {
@@ -117,11 +116,8 @@ float tanhf(float x) { return sinhf(x) / coshf(x); }
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float acoshf(float x) { return 0.0; }
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float asinhf(float x) { return 0.0; }
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float atanhf(float x) { return 0.0; }
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float tanf(float x) { return 0.0; }
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float acosf(float x) { return 0.0; }
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float asinf(float x) { return 0.0; }
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float atanf(float x) { return 0.0; }
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float atan2f(float x, float y) { return 0.0; }
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float fmodf(float x, float y) { return 0.0; }
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float tgammaf(float x) { return 0.0; }
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float lgammaf(float x) { return 0.0; }
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float frexpf(float x, int *exp) { return 0.0; }
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float ldexpf(float x, int exp) { return 0.0; }
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/*****************************************************************************/
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/*****************************************************************************/
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// from musl-0.9.15 libm.h
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/*****************************************************************************/
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/*****************************************************************************/
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/* origin: FreeBSD /usr/src/lib/msun/src/math_private.h */
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
144-
*
145-
* Developed at SunPro, a Sun Microsystems, Inc. business.
146-
* Permission to use, copy, modify, and distribute this
147-
* software is freely granted, provided that this notice
148-
* is preserved.
149-
* ====================================================
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*/
151-
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#define FORCE_EVAL(x) do { \
153-
if (sizeof(x) == sizeof(float)) { \
154-
volatile float __x; \
155-
__x = (x); \
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(void)__x; \
157-
} else if (sizeof(x) == sizeof(double)) { \
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volatile double __x; \
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__x = (x); \
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(void)__x; \
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} else { \
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volatile long double __x; \
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__x = (x); \
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(void)__x; \
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} \
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} while(0)
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/* Get a 32 bit int from a float. */
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#define GET_FLOAT_WORD(w,d) \
170-
do { \
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union {float f; uint32_t i;} __u; \
172-
__u.f = (d); \
173-
(w) = __u.i; \
174-
} while (0)
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/* Set a float from a 32 bit int. */
177-
#define SET_FLOAT_WORD(d,w) \
178-
do { \
179-
union {float f; uint32_t i;} __u; \
180-
__u.i = (w); \
181-
(d) = __u.f; \
182-
} while (0)
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184130
/*****************************************************************************/
185131
/*****************************************************************************/
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// __fpclassifyf from musl-0.9.15

stmhal/mathsincos.c renamed to lib/libm/mathsincos.c

File renamed without changes.

‎stmhal/Makefile‎

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@@ -60,6 +60,13 @@ endif
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# uncomment this if you want libgcc
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#LIBS += $(shell $(CC) -print-libgcc-file-name)
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SRC_LIB = $(addprefix lib/,\
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libm/math.c \
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libm/mathsincos.c \
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libm/atanf.c \
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libm/atan2f.c \
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)
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6370
SRC_C = \
6471
main.c \
6572
string0.c \
@@ -84,8 +91,6 @@ SRC_C = \
8491
uart.c \
8592
usb.c \
8693
printf.c \
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math.c \
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mathsincos.c \
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gccollect.c \
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pybstdio.c \
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readline.c \
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194199
OBJ =
195200
OBJ += $(PY_O)
201+
OBJ += $(addprefix $(BUILD)/, $(SRC_LIB:.c=.o))
196202
OBJ += $(addprefix $(BUILD)/, $(SRC_C:.c=.o))
197203
OBJ += $(addprefix $(BUILD)/, $(SRC_S:.s=.o))
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OBJ += $(addprefix $(BUILD)/, $(SRC_HAL:.c=.o))

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