return _mesa_float_to_half(f);
}
+static inline uint16_t
+util_float_to_half_rtz(float f)
+{
+ uint32_t sign_mask = 0x80000000;
+ uint32_t round_mask = ~0xfff;
+ uint32_t f32inf = 0xff << 23;
+ uint32_t f16inf = 0x1f << 23;
+ uint32_t sign;
+ union fi magic;
+ union fi f32;
+ uint16_t f16;
+
+ magic.ui = 0xf << 23;
+
+ f32.f = f;
+
+ /* Sign */
+ sign = f32.ui & sign_mask;
+ f32.ui ^= sign;
+
+ if (f32.ui == f32inf) {
+ /* Inf */
+ f16 = 0x7c00;
+ } else if (f32.ui > f32inf) {
+ /* NaN */
+ f16 = 0x7e00;
+ } else {
+ /* Number */
+ f32.ui &= round_mask;
+ f32.f *= magic.f;
+ f32.ui -= round_mask;
+ /*
+ * XXX: The magic mul relies on denorms being available, otherwise
+ * all f16 denorms get flushed to zero - hence when this is used
+ * for tgsi_exec in softpipe we won't get f16 denorms.
+ */
+ /*
+ * Clamp to max finite value if overflowed.
+ * OpenGL has completely undefined rounding behavior for float to
+ * half-float conversions, and this matches what is mandated for float
+ * to fp11/fp10, which recommend round-to-nearest-finite too.
+ * (d3d10 is deeply unhappy about flushing such values to infinity, and
+ * while it also mandates round-to-zero it doesn't care nearly as much
+ * about that.)
+ */
+ if (f32.ui > f16inf)
+ f32.ui = f16inf - 1;
+
+ f16 = f32.ui >> 13;
+ }
+
+ /* Sign */
+ f16 |= sign >> 16;
+
+ return f16;
+}
+
static inline float
util_half_to_float(uint16_t f16)
{