fix aliasing-based undefined behavior in mbsrtowcs

[musl] / src / math / asinf.c

diff --git a/src/math/asinf.c b/src/math/asinf.c
index 462bf04..bcd304a 100644 (file)
--- a/src/math/asinf.c
+++ b/src/math/asinf.c
@@ -26,7 +26,7 @@ qS1 = -7.0662963390e-01;
 
 static float R(float z)
 {
-       float p, q;
+       float_t p, q;
        p = z*(pS0+z*(pS1+z*pS2));
        q = 1.0f+z*qS1;
        return p/q;
@@ -46,10 +46,9 @@ float asinf(float x)
                return 0/(x-x);  /* asin(|x|>1) is NaN */
        }
        if (ix < 0x3f000000) {  /* |x| < 0.5 */
-               if (ix < 0x39800000) {  /* |x| < 2**-12 */
-                       FORCE_EVAL(x + 0x1p120f);
-                       return x; /* return x with inexact if x!=0 */
-               }
+               /* if 0x1p-126 <= |x| < 0x1p-12, avoid raising underflow */
+               if (ix < 0x39800000 && ix >= 0x00800000)
+                       return x;
                return x + x*R(x*x);
        }
        /* 1 > |x| >= 0.5 */