Change rtn to rtz to improve performance

include/ck/utility/data_type.hpp

@@ -974,38 +974,38 @@ inline __host__ __device__ constexpr bhalf_t type_convert<bhalf_t, float>(float
         uint32_t int32;
     } u = {x};
 
-    if(~u.int32 & 0x7f800000)
-    {
-        // When the exponent bits are not all 1s, then the value is zero, normal,
-        // or subnormal. We round the bfloat16 mantissa up by adding 0x7FFF, plus
-        // 1 if the least significant bit of the bfloat16 mantissa is 1 (odd).
-        // This causes the bfloat16's mantissa to be incremented by 1 if the 16
-        // least significant bits of the float mantissa are greater than 0x8000,
-        // or if they are equal to 0x8000 and the least significant bit of the
-        // bfloat16 mantissa is 1 (odd). This causes it to be rounded to even when
-        // the lower 16 bits are exactly 0x8000. If the bfloat16 mantissa already
-        // has the value 0x7f, then incrementing it causes it to become 0x00 and
-        // the exponent is incremented by one, which is the next higher FP value
-        // to the unrounded bfloat16 value. When the bfloat16 value is subnormal
-        // with an exponent of 0x00 and a mantissa of 0x7F, it may be rounded up
-        // to a normal value with an exponent of 0x01 and a mantissa of 0x00.
-        // When the bfloat16 value has an exponent of 0xFE and a mantissa of 0x7F,
-        // incrementing it causes it to become an exponent of 0xFF and a mantissa
-        // of 0x00, which is Inf, the next higher value to the unrounded value.
-        u.int32 += 0x7fff + ((u.int32 >> 16) & 1); // Round to nearest, round to even
-    }
-    else if(u.int32 & 0xffff)
-    {
-        // When all of the exponent bits are 1, the value is Inf or NaN.
-        // Inf is indicated by a zero mantissa. NaN is indicated by any nonzero
-        // mantissa bit. Quiet NaN is indicated by the most significant mantissa
-        // bit being 1. Signaling NaN is indicated by the most significant
-        // mantissa bit being 0 but some other bit(s) being 1. If any of the
-        // lower 16 bits of the mantissa are 1, we set the least significant bit
-        // of the bfloat16 mantissa, in order to preserve signaling NaN in case
-        // the bloat16's mantissa bits are all 0.
-        u.int32 |= 0x10000; // Preserve signaling NaN
-    }
+    //if(~u.int32 & 0x7f800000)
+    //{
+    //    // When the exponent bits are not all 1s, then the value is zero, normal,
+    //    // or subnormal. We round the bfloat16 mantissa up by adding 0x7FFF, plus
+    //    // 1 if the least significant bit of the bfloat16 mantissa is 1 (odd).
+    //    // This causes the bfloat16's mantissa to be incremented by 1 if the 16
+    //    // least significant bits of the float mantissa are greater than 0x8000,
+    //    // or if they are equal to 0x8000 and the least significant bit of the
+    //    // bfloat16 mantissa is 1 (odd). This causes it to be rounded to even when
+    //    // the lower 16 bits are exactly 0x8000. If the bfloat16 mantissa already
+    //    // has the value 0x7f, then incrementing it causes it to become 0x00 and
+    //    // the exponent is incremented by one, which is the next higher FP value
+    //    // to the unrounded bfloat16 value. When the bfloat16 value is subnormal
+    //    // with an exponent of 0x00 and a mantissa of 0x7F, it may be rounded up
+    //    // to a normal value with an exponent of 0x01 and a mantissa of 0x00.
+    //    // When the bfloat16 value has an exponent of 0xFE and a mantissa of 0x7F,
+    //    // incrementing it causes it to become an exponent of 0xFF and a mantissa
+    //    // of 0x00, which is Inf, the next higher value to the unrounded value.
+    //    u.int32 += 0x7fff + ((u.int32 >> 16) & 1); // Round to nearest, round to even
+    //}
+    //else if(u.int32 & 0xffff)
+    //{
+    //    // When all of the exponent bits are 1, the value is Inf or NaN.
+    //    // Inf is indicated by a zero mantissa. NaN is indicated by any nonzero
+    //    // mantissa bit. Quiet NaN is indicated by the most significant mantissa
+    //    // bit being 1. Signaling NaN is indicated by the most significant
+    //    // mantissa bit being 0 but some other bit(s) being 1. If any of the
+    //    // lower 16 bits of the mantissa are 1, we set the least significant bit
+    //    // of the bfloat16 mantissa, in order to preserve signaling NaN in case
+    //    // the bloat16's mantissa bits are all 0.
+    //    u.int32 |= 0x10000; // Preserve signaling NaN
+    //}
 
     return uint16_t(u.int32 >> 16);
 }