fix a cbrtl.c regression and remove x87 precision setting

diff --git a/src/math/cbrtl.c b/src/math/cbrtl.c
index 5297d68feb0c19eb197ad7787d44aee4c0ac5485..0af65ef5de55ff6055d7ba96e4b03d8e1f6b9106 100644 (file)
--- a/src/math/cbrtl.c
+++ b/src/math/cbrtl.c
@@ -23,9 +23,9 @@ long double cbrtl(long double x)
        return cbrt(x);
 }
 #elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384
-#define BIAS    (LDBL_MAX_EXP - 1)
-static const unsigned
-B1 = 709958130; /* B1 = (127-127.0/3-0.03306235651)*2**23 */
+
+#define BIAS (LDBL_MAX_EXP - 1)
+static const unsigned B1 = 709958130; /* B1 = (127-127.0/3-0.03306235651)*2**23 */
 
 long double cbrtl(long double x)
 {
@@ -48,25 +48,10 @@ long double cbrtl(long double x)
        if (k == BIAS + LDBL_MAX_EXP)
                return x + x;
 
-// FIXME: extended precision is default on linux..
-#undef __i386__
-#ifdef __i386__
-       fp_prec_t oprec;
-
-       oprec = fpgetprec();
-       if (oprec != FP_PE)
-               fpsetprec(FP_PE);
-#endif
-
        if (k == 0) {
                /* If x = +-0, then cbrt(x) = +-0. */
-               if ((u.bits.manh | u.bits.manl) == 0) {
-#ifdef __i386__
-                       if (oprec != FP_PE)
-                               fpsetprec(oprec);
-#endif
-                       return (x);
-               }
+               if ((u.bits.manh | u.bits.manl) == 0)
+                       return x;
                /* Adjust subnormal numbers. */
                u.e *= 0x1.0p514;
                k = u.bits.exp;
@@ -118,7 +103,7 @@ long double cbrtl(long double x)
         * Round it away from zero to 32 bits (32 so that t*t is exact, and
         * away from zero for technical reasons).
         */
-       t = dt + (0x1.0p32L + 0x1.0p-32L) - 0x1.0p32;
+       t = dt + (0x1.0p32L + 0x1.0p-31L) - 0x1.0p32;
 #elif LDBL_MANT_DIG == 113
        /*
         * Round dt away from zero to 47 bits.  Since we don't trust the 47,
@@ -129,8 +114,6 @@ long double cbrtl(long double x)
         * dt is much more accurate than needed.
         */
        t = dt + 0x2.0p-46 + 0x1.0p60L - 0x1.0p60;
-#else
-#error "Unsupported long double format"
 #endif
 
        /*
@@ -144,10 +127,6 @@ long double cbrtl(long double x)
        t = t+t*r;       /* error <= 0.5 + 0.5/3 + epsilon */
 
        t *= v.e;
-#ifdef __i386__
-       if (oprec != FP_PE)
-               fpsetprec(oprec);
-#endif
        return t;
 }
 #endif