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3a8e01a77a
Somehow or another, I previously had missed `BUILD.mk` files. In the process I found a few straggler cases where the modeline was different from the file, including one very involved manual fix where a file had been treated like it was ts=2 and ts=8 on separate occasions. The commit history in the PR shows the gory details; the BUILD.mk was automated, everything else was mostly manual.
154 lines
6.5 KiB
C
154 lines
6.5 KiB
C
/*-*- mode:c;indent-tabs-mode:t;c-basic-offset:8;tab-width:8;coding:utf-8 -*-│
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│ vi: set noet ft=c ts=8 sw=8 fenc=utf-8 :vi │
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╚──────────────────────────────────────────────────────────────────────────────╝
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│ │
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│ FreeBSD lib/msun/src/s_expm1f.c │
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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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│ Copyright (c) 1992-2023 The FreeBSD Project. │
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│ │
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│ Redistribution and use in source and binary forms, with or without │
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│ modification, are permitted provided that the following conditions │
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│ are met: │
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│ 1. Redistributions of source code must retain the above copyright │
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│ notice, this list of conditions and the following disclaimer. │
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│ 2. Redistributions in binary form must reproduce the above copyright │
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│ notice, this list of conditions and the following disclaimer in the │
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│ documentation and/or other materials provided with the distribution. │
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│ │
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│ THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND │
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│ ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE │
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│ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE │
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│ ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE │
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│ FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL │
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│ DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS │
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│ OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) │
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│ HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT │
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│ LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY │
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│ OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF │
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│ SUCH DAMAGE. │
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│ │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/math.h"
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#include "libc/tinymath/freebsd.internal.h"
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asm(".ident\t\"\\n\\n\
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FreeBSD libm (BSD-2 License)\\n\
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Copyright (c) 2005-2011, Bruce D. Evans, Steven G. Kargl, David Schultz.\"");
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asm(".ident\t\"\\n\\n\
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fdlibm (fdlibm license)\\n\
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Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.\"");
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asm(".include \"libc/disclaimer.inc\"");
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// clang-format off
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static const float
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one = 1.0,
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tiny = 1.0e-30,
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o_threshold = 8.8721679688e+01,/* 0x42b17180 */
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ln2_hi = 6.9313812256e-01,/* 0x3f317180 */
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ln2_lo = 9.0580006145e-06,/* 0x3717f7d1 */
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invln2 = 1.4426950216e+00,/* 0x3fb8aa3b */
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/*
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* Domain [-0.34568, 0.34568], range ~[-6.694e-10, 6.696e-10]:
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* |6 / x * (1 + 2 * (1 / (exp(x) - 1) - 1 / x)) - q(x)| < 2**-30.04
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* Scaled coefficients: Qn_here = 2**n * Qn_for_q (see s_expm1.c):
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*/
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Q1 = -3.3333212137e-2, /* -0x888868.0p-28 */
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Q2 = 1.5807170421e-3; /* 0xcf3010.0p-33 */
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static volatile float huge = 1.0e+30;
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/**
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* Returns 𝑒ˣ-1.
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*/
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float
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expm1f(float x)
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{
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float y,hi,lo,c,t,e,hxs,hfx,r1,twopk;
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int32_t k,xsb;
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uint32_t hx;
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GET_FLOAT_WORD(hx,x);
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xsb = hx&0x80000000; /* sign bit of x */
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hx &= 0x7fffffff; /* high word of |x| */
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/* filter out huge and non-finite argument */
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if(hx >= 0x4195b844) { /* if |x|>=27*ln2 */
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if(hx >= 0x42b17218) { /* if |x|>=88.721... */
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if(hx>0x7f800000)
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return x+x; /* NaN */
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if(hx==0x7f800000)
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return (xsb==0)? x:-1.0;/* exp(+-inf)={inf,-1} */
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if(x > o_threshold) return huge*huge; /* overflow */
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}
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if(xsb!=0) { /* x < -27*ln2, return -1.0 with inexact */
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if(x+tiny<(float)0.0) /* raise inexact */
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return tiny-one; /* return -1 */
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}
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}
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/* argument reduction */
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if(hx > 0x3eb17218) { /* if |x| > 0.5 ln2 */
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if(hx < 0x3F851592) { /* and |x| < 1.5 ln2 */
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if(xsb==0)
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{hi = x - ln2_hi; lo = ln2_lo; k = 1;}
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else
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{hi = x + ln2_hi; lo = -ln2_lo; k = -1;}
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} else {
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k = invln2*x+((xsb==0)?(float)0.5:(float)-0.5);
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t = k;
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hi = x - t*ln2_hi; /* t*ln2_hi is exact here */
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lo = t*ln2_lo;
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}
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STRICT_ASSIGN(float, x, hi - lo);
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c = (hi-x)-lo;
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}
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else if(hx < 0x33000000) { /* when |x|<2**-25, return x */
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t = huge+x; /* return x with inexact flags when x!=0 */
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return x - (t-(huge+x));
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}
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else k = 0;
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/* x is now in primary range */
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hfx = (float)0.5*x;
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hxs = x*hfx;
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r1 = one+hxs*(Q1+hxs*Q2);
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t = (float)3.0-r1*hfx;
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e = hxs*((r1-t)/((float)6.0 - x*t));
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if(k==0) return x - (x*e-hxs); /* c is 0 */
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else {
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SET_FLOAT_WORD(twopk,((uint32_t)(0x7f+k))<<23); /* 2^k */
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e = (x*(e-c)-c);
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e -= hxs;
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if(k== -1) return (float)0.5*(x-e)-(float)0.5;
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if(k==1) {
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if(x < (float)-0.25) return -(float)2.0*(e-(x+(float)0.5));
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else return one+(float)2.0*(x-e);
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}
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if (k <= -2 || k>56) { /* suffice to return exp(x)-1 */
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y = one-(e-x);
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if (k == 128) y = y*2.0F*0x1p127F;
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else y = y*twopk;
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return y-one;
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}
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t = one;
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if(k<23) {
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SET_FLOAT_WORD(t,0x3f800000 - (0x1000000>>k)); /* t=1-2^-k */
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y = t-(e-x);
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y = y*twopk;
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} else {
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SET_FLOAT_WORD(t,((0x7f-k)<<23)); /* 2^-k */
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y = x-(e+t);
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y += one;
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y = y*twopk;
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}
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}
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return y;
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}
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