[fusl] clang-format fusl

fusl/src/math/log2.c

 /* origin: FreeBSD /usr/src/lib/msun/src/e_log2.c */
 /*
  * ====================================================
  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
  *
  * Developed at SunSoft, a Sun Microsystems, Inc. business.
  * Permission to use, copy, modify, and distribute this
  * software is freely granted, provided that this notice
  * is preserved.
  * ====================================================
  */
 /*
  * Return the base 2 logarithm of x.  See log.c for most comments.
  *
  * Reduce x to 2^k (1+f) and calculate r = log(1+f) - f + f*f/2
  * as in log.c, then combine and scale in extra precision:
  *    log2(x) = (f - f*f/2 + r)/log(2) + k
  */
 
 #include <math.h>
 #include <stdint.h>
 
-static const double
-ivln2hi = 1.44269504072144627571e+00, /* 0x3ff71547, 0x65200000 */
-ivln2lo = 1.67517131648865118353e-10, /* 0x3de705fc, 0x2eefa200 */
-Lg1 = 6.666666666666735130e-01,  /* 3FE55555 55555593 */
-Lg2 = 3.999999999940941908e-01,  /* 3FD99999 9997FA04 */
-Lg3 = 2.857142874366239149e-01,  /* 3FD24924 94229359 */
-Lg4 = 2.222219843214978396e-01,  /* 3FCC71C5 1D8E78AF */
-Lg5 = 1.818357216161805012e-01,  /* 3FC74664 96CB03DE */
-Lg6 = 1.531383769920937332e-01,  /* 3FC39A09 D078C69F */
-Lg7 = 1.479819860511658591e-01;  /* 3FC2F112 DF3E5244 */
+static const double ivln2hi =
+                        1.44269504072144627571e+00, /* 0x3ff71547, 0x65200000 */
+    ivln2lo = 1.67517131648865118353e-10,           /* 0x3de705fc, 0x2eefa200 */
+    Lg1 = 6.666666666666735130e-01,                 /* 3FE55555 55555593 */
+    Lg2 = 3.999999999940941908e-01,                 /* 3FD99999 9997FA04 */
+    Lg3 = 2.857142874366239149e-01,                 /* 3FD24924 94229359 */
+    Lg4 = 2.222219843214978396e-01,                 /* 3FCC71C5 1D8E78AF */
+    Lg5 = 1.818357216161805012e-01,                 /* 3FC74664 96CB03DE */
+    Lg6 = 1.531383769920937332e-01,                 /* 3FC39A09 D078C69F */
+    Lg7 = 1.479819860511658591e-01;                 /* 3FC2F112 DF3E5244 */
 
-double log2(double x)
-{
-        union {double f; uint64_t i;} u = {x};
-        double_t hfsq,f,s,z,R,w,t1,t2,y,hi,lo,val_hi,val_lo;
-        uint32_t hx;
-        int k;
+double log2(double x) {
+  union {
+    double f;
+    uint64_t i;
+  } u = {x};
+  double_t hfsq, f, s, z, R, w, t1, t2, y, hi, lo, val_hi, val_lo;
+  uint32_t hx;
+  int k;
 
-        hx = u.i>>32;
-        k = 0;
-        if (hx < 0x00100000 || hx>>31) {
-                if (u.i<<1 == 0)
-                        return -1/(x*x);  /* log(+-0)=-inf */
-                if (hx>>31)
-                        return (x-x)/0.0; /* log(-#) = NaN */
-                /* subnormal number, scale x up */
-                k -= 54;
-                x *= 0x1p54;
-                u.f = x;
-                hx = u.i>>32;
-        } else if (hx >= 0x7ff00000) {
-                return x;
-        } else if (hx == 0x3ff00000 && u.i<<32 == 0)
-                return 0;
+  hx = u.i >> 32;
+  k = 0;
+  if (hx < 0x00100000 || hx >> 31) {
+    if (u.i << 1 == 0)
+      return -1 / (x * x); /* log(+-0)=-inf */
+    if (hx >> 31)
+      return (x - x) / 0.0; /* log(-#) = NaN */
+    /* subnormal number, scale x up */
+    k -= 54;
+    x *= 0x1p54;
+    u.f = x;
+    hx = u.i >> 32;
+  } else if (hx >= 0x7ff00000) {
+    return x;
+  } else if (hx == 0x3ff00000 && u.i << 32 == 0)
+    return 0;
 
-        /* reduce x into [sqrt(2)/2, sqrt(2)] */
-        hx += 0x3ff00000 - 0x3fe6a09e;
-        k += (int)(hx>>20) - 0x3ff;
-        hx = (hx&0x000fffff) + 0x3fe6a09e;
-        u.i = (uint64_t)hx<<32 | (u.i&0xffffffff);
-        x = u.f;
+  /* reduce x into [sqrt(2)/2, sqrt(2)] */
+  hx += 0x3ff00000 - 0x3fe6a09e;
+  k += (int)(hx >> 20) - 0x3ff;
+  hx = (hx & 0x000fffff) + 0x3fe6a09e;
+  u.i = (uint64_t)hx << 32 | (u.i & 0xffffffff);
+  x = u.f;
 
-        f = x - 1.0;
-        hfsq = 0.5*f*f;
-        s = f/(2.0+f);
-        z = s*s;
-        w = z*z;
-        t1 = w*(Lg2+w*(Lg4+w*Lg6));
-        t2 = z*(Lg1+w*(Lg3+w*(Lg5+w*Lg7)));
-        R = t2 + t1;
+  f = x - 1.0;
+  hfsq = 0.5 * f * f;
+  s = f / (2.0 + f);
+  z = s * s;
+  w = z * z;
+  t1 = w * (Lg2 + w * (Lg4 + w * Lg6));
+  t2 = z * (Lg1 + w * (Lg3 + w * (Lg5 + w * Lg7)));
+  R = t2 + t1;
 
-        /*
-         * f-hfsq must (for args near 1) be evaluated in extra precision
-         * to avoid a large cancellation when x is near sqrt(2) or 1/sqrt(2).
-         * This is fairly efficient since f-hfsq only depends on f, so can
-         * be evaluated in parallel with R.  Not combining hfsq with R also
-         * keeps R small (though not as small as a true `lo' term would be),
-         * so that extra precision is not needed for terms involving R.
-         *
-         * Compiler bugs involving extra precision used to break Dekker's
-         * theorem for spitting f-hfsq as hi+lo, unless double_t was used
-         * or the multi-precision calculations were avoided when double_t
-         * has extra precision.  These problems are now automatically
-         * avoided as a side effect of the optimization of combining the
-         * Dekker splitting step with the clear-low-bits step.
-         *
-         * y must (for args near sqrt(2) and 1/sqrt(2)) be added in extra
-         * precision to avoid a very large cancellation when x is very near
-         * these values.  Unlike the above cancellations, this problem is
-         * specific to base 2.  It is strange that adding +-1 is so much
-         * harder than adding +-ln2 or +-log10_2.
-         *
-         * This uses Dekker's theorem to normalize y+val_hi, so the
-         * compiler bugs are back in some configurations, sigh.  And I
-         * don't want to used double_t to avoid them, since that gives a
-         * pessimization and the support for avoiding the pessimization
-         * is not yet available.
-         *
-         * The multi-precision calculations for the multiplications are
-         * routine.
-         */
+  /*
+   * f-hfsq must (for args near 1) be evaluated in extra precision
+   * to avoid a large cancellation when x is near sqrt(2) or 1/sqrt(2).
+   * This is fairly efficient since f-hfsq only depends on f, so can
+   * be evaluated in parallel with R.  Not combining hfsq with R also
+   * keeps R small (though not as small as a true `lo' term would be),
+   * so that extra precision is not needed for terms involving R.
+   *
+   * Compiler bugs involving extra precision used to break Dekker's
+   * theorem for spitting f-hfsq as hi+lo, unless double_t was used
+   * or the multi-precision calculations were avoided when double_t
+   * has extra precision.  These problems are now automatically
+   * avoided as a side effect of the optimization of combining the
+   * Dekker splitting step with the clear-low-bits step.
+   *
+   * y must (for args near sqrt(2) and 1/sqrt(2)) be added in extra
+   * precision to avoid a very large cancellation when x is very near
+   * these values.  Unlike the above cancellations, this problem is
+   * specific to base 2.  It is strange that adding +-1 is so much
+   * harder than adding +-ln2 or +-log10_2.
+   *
+   * This uses Dekker's theorem to normalize y+val_hi, so the
+   * compiler bugs are back in some configurations, sigh.  And I
+   * don't want to used double_t to avoid them, since that gives a
+   * pessimization and the support for avoiding the pessimization
+   * is not yet available.
+   *
+   * The multi-precision calculations for the multiplications are
+   * routine.
+   */
 
-        /* hi+lo = f - hfsq + s*(hfsq+R) ~ log(1+f) */
-        hi = f - hfsq;
-        u.f = hi;
-        u.i &= (uint64_t)-1<<32;
-        hi = u.f;
-        lo = f - hi - hfsq + s*(hfsq+R);
+  /* hi+lo = f - hfsq + s*(hfsq+R) ~ log(1+f) */
+  hi = f - hfsq;
+  u.f = hi;
+  u.i &= (uint64_t)-1 << 32;
+  hi = u.f;
+  lo = f - hi - hfsq + s * (hfsq + R);
 
-        val_hi = hi*ivln2hi;
-        val_lo = (lo+hi)*ivln2lo + lo*ivln2hi;
+  val_hi = hi * ivln2hi;
+  val_lo = (lo + hi) * ivln2lo + lo * ivln2hi;
 
-        /* spadd(val_hi, val_lo, y), except for not using double_t: */
-        y = k;
-        w = y + val_hi;
-        val_lo += (y - w) + val_hi;
-        val_hi = w;
+  /* spadd(val_hi, val_lo, y), except for not using double_t: */
+  y = k;
+  w = y + val_hi;
+  val_lo += (y - w) + val_hi;
+  val_hi = w;
 
-        return val_lo + val_hi;
+  return val_lo + val_hi;
 }