make fma and lrint functions build without full fenv support

this is necessary to support archs where fenv is incomplete or
unavailable (presently arm). fma, fmal, and the lrint family should
work perfectly fine with this change; fmaf is slightly broken with
respect to rounding as it depends on non-default rounding modes to do
its work.

diff --git a/src/math/fma.c b/src/math/fma.c
index c53f314..f44ecda 100644 (file)
--- a/src/math/fma.c
+++ b/src/math/fma.c
@@ -199,27 +199,37 @@ double fma(double x, double y, double z)
         * modes other than FE_TONEAREST are painful.
         */
        if (spread < -DBL_MANT_DIG) {
+#ifdef FE_INEXACT
                feraiseexcept(FE_INEXACT);
+#endif
+#ifdef FE_UNDERFLOW
                if (!isnormal(z))
                        feraiseexcept(FE_UNDERFLOW);
+#endif
                switch (oround) {
-               case FE_TONEAREST:
+               default: /* FE_TONEAREST */
                        return (z);
+#ifdef FE_TOWARDZERO
                case FE_TOWARDZERO:
                        if (x > 0.0 ^ y < 0.0 ^ z < 0.0)
                                return (z);
                        else
                                return (nextafter(z, 0));
+#endif
+#ifdef FE_DOWNWARD
                case FE_DOWNWARD:
                        if (x > 0.0 ^ y < 0.0)
                                return (z);
                        else
                                return (nextafter(z, -INFINITY));
-               default:        /* FE_UPWARD */
+#endif
+#ifdef FE_UPWARD
+               case FE_UPWARD:
                        if (x > 0.0 ^ y < 0.0)
                                return (nextafter(z, INFINITY));
                        else
                                return (z);
+#endif
                }
        }
        if (spread <= DBL_MANT_DIG * 2)

diff --git a/src/math/fmaf.c b/src/math/fmaf.c
index 0dccf10..cc427fb 100644 (file)
--- a/src/math/fmaf.c
+++ b/src/math/fmaf.c
@@ -54,7 +54,9 @@ float fmaf(float x, float y, float z)
         * If result is inexact, and exactly halfway between two float values,
         * we need to adjust the low-order bit in the direction of the error.
         */
+#ifdef FE_TOWARDZERO
        fesetround(FE_TOWARDZERO);
+#endif
        volatile double vxy = xy;  /* XXX work around gcc CSE bug */
        double adjusted_result = vxy + z;
        fesetround(FE_TONEAREST);

diff --git a/src/math/fmal.c b/src/math/fmal.c
index 200bd5a..3944c29 100644 (file)
--- a/src/math/fmal.c
+++ b/src/math/fmal.c
@@ -194,27 +194,37 @@ long double fmal(long double x, long double y, long double z)
         * modes other than FE_TONEAREST are painful.
         */
        if (spread < -LDBL_MANT_DIG) {
+#ifdef FE_INEXACT
                feraiseexcept(FE_INEXACT);
+#endif
+#ifdef FE_UNDERFLOW
                if (!isnormal(z))
                        feraiseexcept(FE_UNDERFLOW);
+#endif
                switch (oround) {
-               case FE_TONEAREST:
+               default: /* FE_TONEAREST */
                        return (z);
+#ifdef FE_TOWARDZERO
                case FE_TOWARDZERO:
                        if (x > 0.0 ^ y < 0.0 ^ z < 0.0)
                                return (z);
                        else
                                return (nextafterl(z, 0));
+#endif
+#ifdef FE_DOWNWARD
                case FE_DOWNWARD:
                        if (x > 0.0 ^ y < 0.0)
                                return (z);
                        else
                                return (nextafterl(z, -INFINITY));
-               default:        /* FE_UPWARD */
+#endif
+#ifdef FE_UPWARD
+               case FE_UPWARD:
                        if (x > 0.0 ^ y < 0.0)
                                return (nextafterl(z, INFINITY));
                        else
                                return (z);
+#endif
                }
        }
        if (spread <= LDBL_MANT_DIG * 2)

diff --git a/src/math/lrint.c b/src/math/lrint.c
index 98d58ad..9754fa7 100644 (file)
--- a/src/math/lrint.c
+++ b/src/math/lrint.c
@@ -49,8 +49,10 @@ dtype fn(type x)
 
        feholdexcept(&env);
        d = (dtype)roundit(x);
+#if defined(FE_INVALID) && defined(FE_INEXACT)
        if (fetestexcept(FE_INVALID))
                feclearexcept(FE_INEXACT);
+#endif
        feupdateenv(&env);
        return d;
 }