getaddrinfo: add EAI_NODATA error code to distinguish NODATA vs NxDomain

[musl] / src / math / expm1f.c

diff --git a/src/math/expm1f.c b/src/math/expm1f.c
index d956846..09a41af 100644 (file)
--- a/src/math/expm1f.c
+++ b/src/math/expm1f.c
@@ -16,9 +16,6 @@
 #include "libm.h"
 
 static const float
-huge        = 1.0e+30,
-tiny        = 1.0e-30,
-o_threshold = 8.8721679688e+01, /* 0x42b17180 */
 ln2_hi      = 6.9313812256e-01, /* 0x3f317180 */
 ln2_lo      = 9.0580006145e-06, /* 0x3717f7d1 */
 invln2      = 1.4426950216e+00, /* 0x3fb8aa3b */
@@ -32,35 +29,27 @@ Q2 =  1.5807170421e-3; /*  0xcf3010.0p-33 */
 
 float expm1f(float x)
 {
-       float y,hi,lo,c,t,e,hxs,hfx,r1,twopk;
-       int32_t k,xsb;
-       uint32_t hx;
-
-       GET_FLOAT_WORD(hx, x);
-       xsb = hx&0x80000000;  /* sign bit of x */
-       hx &= 0x7fffffff;     /* high word of |x| */
+       float_t y,hi,lo,c,t,e,hxs,hfx,r1,twopk;
+       union {float f; uint32_t i;} u = {x};
+       uint32_t hx = u.i & 0x7fffffff;
+       int k, sign = u.i >> 31;
 
        /* filter out huge and non-finite argument */
        if (hx >= 0x4195b844) {  /* if |x|>=27*ln2 */
-               if (hx >= 0x42b17218) {  /* if |x|>=88.721... */
-                       if (hx > 0x7f800000)  /* NaN */
-                               return x+x;
-                       if (hx == 0x7f800000) /* exp(+-inf)={inf,-1} */
-                               return xsb==0 ? x : -1.0;
-                       if (x > o_threshold)
-                               return huge*huge; /* overflow */
-               }
-               if (xsb != 0) {  /* x < -27*ln2 */
-                       /* raise inexact */
-                       if (x+tiny < 0.0f)
-                               return tiny-1.0f;  /* return -1 */
+               if (hx > 0x7f800000)  /* NaN */
+                       return x;
+               if (sign)
+                       return -1;
+               if (hx > 0x42b17217) { /* x > log(FLT_MAX) */
+                       x *= 0x1p127f;
+                       return x;
                }
        }
 
        /* argument reduction */
        if (hx > 0x3eb17218) {           /* if  |x| > 0.5 ln2 */
                if (hx < 0x3F851592) {       /* and |x| < 1.5 ln2 */
-                       if (xsb == 0) {
+                       if (!sign) {
                                hi = x - ln2_hi;
                                lo = ln2_lo;
                                k =  1;
@@ -70,16 +59,17 @@ float expm1f(float x)
                                k = -1;
                        }
                } else {
-                       k  = invln2*x + (xsb==0 ? 0.5f : -0.5f);
+                       k  = invln2*x + (sign ? -0.5f : 0.5f);
                        t  = k;
                        hi = x - t*ln2_hi;      /* t*ln2_hi is exact here */
                        lo = t*ln2_lo;
                }
-               STRICT_ASSIGN(float, x, hi - lo);
+               x = hi-lo;
                c = (hi-x)-lo;
        } else if (hx < 0x33000000) {  /* when |x|<2**-25, return x */
-               t = huge+x; /* return x with inexact flags when x!=0 */
-               return x - (t-(huge+x));
+               if (hx < 0x00800000)
+                       FORCE_EVAL(x*x);
+               return x;
        } else
                k = 0;
 
@@ -91,9 +81,9 @@ float expm1f(float x)
        e  = hxs*((r1-t)/(6.0f - x*t));
        if (k == 0)  /* c is 0 */
                return x - (x*e-hxs);
-       SET_FLOAT_WORD(twopk, 0x3f800000+(k<<23));   /* 2^k */
        e  = x*(e-c) - c;
        e -= hxs;
+       /* exp(x) ~ 2^k (x_reduced - e + 1) */
        if (k == -1)
                return 0.5f*(x-e) - 0.5f;
        if (k == 1) {
@@ -101,24 +91,20 @@ float expm1f(float x)
                        return -2.0f*(e-(x+0.5f));
                return 1.0f + 2.0f*(x-e);
        }
-       if (k <= -2 || k > 56) {   /* suffice to return exp(x)-1 */
-               y = 1.0f - (e - x);
+       u.i = (0x7f+k)<<23;  /* 2^k */
+       twopk = u.f;
+       if (k < 0 || k > 56) {   /* suffice to return exp(x)-1 */
+               y = x - e + 1.0f;
                if (k == 128)
                        y = y*2.0f*0x1p127f;
                else
                        y = y*twopk;
                return y - 1.0f;
        }
-       t = 1.0f;
-       if (k < 23) {
-               SET_FLOAT_WORD(t, 0x3f800000 - (0x1000000>>k)); /* t=1-2^-k */
-               y = t - (e - x);
-               y = y*twopk;
-       } else {
-               SET_FLOAT_WORD(t, (0x7f-k)<<23);  /* 2^-k */
-               y = x - (e + t);
-               y += 1.0f;
-               y = y*twopk;
-       }
+       u.i = (0x7f-k)<<23;  /* 2^-k */
+       if (k < 23)
+               y = (x-e+(1-u.f))*twopk;
+       else
+               y = (x-(e+u.f)+1)*twopk;
        return y;
 }