math: fix x86 asin accuracy

[musl] / src / math / i386 / asin.s

diff --git a/src/math/i386/asin.s b/src/math/i386/asin.s
index cab7bfc..932c754 100644 (file)
--- a/src/math/i386/asin.s
+++ b/src/math/i386/asin.s
@@ -15,9 +15,10 @@ asinl:
 asin:
        fldl 4(%esp)
 1:     fld %st(0)
-       fmul %st(0)
        fld1
-       fsubp %st(1)
+       fsub %st(0),%st(1)
+       fadd %st(2)
+       fmulp
        fsqrt
        fpatan
        ret