added half2 log, log10, exp, exp10 math functions

1. Enabled tests for log, log10, exp, exp10 half2
2. h2rint is still disabled.

Change-Id: I01f6002f6992259919893c524c526db5ee09473a


[ROCm/hip commit: bf45105c7c]

projects/hip/include/hip/hcc_detail/hip_fp16.h

@@ -709,6 +709,22 @@ __device__ static inline __half2 h2cos(const __half2 h) {
   return a;
 }
 
+__device__ static inline __half2 h2exp(const __half2 h) {
+  __half2 factor;
+  factor.p[0] = 1.442694;
+  factor.p[1] = 1.442694;
+  factor.q = __hip_hc_ir_h2exp2_int(__hip_hc_ir_hmul2_int(h.q, factor.q));
+  return factor;
+}
+
+__device__ static inline __half2 h2exp10(const __half2 h) {
+  __half2 factor;
+  factor.p[0] = 3.3219281;
+  factor.p[1] = 3.3219281;
+  factor.q = __hip_hc_ir_h2exp2_int(__hip_hc_ir_hmul2_int(h.q, factor.q));
+  return factor;
+}
+
 __device__ static inline __half2 h2exp2(const __half2 h) {
   __half2 a;
   a.q = __hip_hc_ir_h2exp2_int(h.q);
@@ -721,6 +737,21 @@ __device__ static inline __half2 h2floor(const __half2 h) {
   return a;
 }
 
+__device__ static inline __half2 h2log(const __half2 h) {
+  __half2 factor;
+  factor.p[0] = 0.693147;
+  factor.p[1] = 0.693147;
+  factor. q = __hip_hc_ir_hmul2_int(__hip_hc_ir_h2log2_int(h.q), factor.q);
+  return factor;
+}
+
+__device__ static inline __half2 h2log10(const __half2 h) {
+  __half2 factor;
+  factor.p[0] = 0.301029;
+  factor.p[1] = 0.301029;
+  factor.q = __hip_hc_ir_hmul2_int(__hip_hc_ir_h2log2_int(h.q),  factor.q);
+  return factor;
+}
 __device__ static inline __half2 h2log2(const __half2 h) {
   __half2 a;
   a.q = __hip_hc_ir_h2log2_int(h.q);

projects/hip/tests/src/deviceLib/hipTestHalf.cpp

@@ -90,12 +90,12 @@ __global__ void CheckHalf2(hipLaunchParm lp, __half2* In1, __half2* In2, __half2
   Out[9] = h2div(In1[9], In2[9]);
   Out[10] = h2ceil(In1[10]);
   Out[11] = h2cos(In1[11]);
-//  Out[12] = h2exp(In1[12]);
-//  Out[13] = h2exp10(In1[13]);
+  Out[12] = h2exp(In1[12]);
+  Out[13] = h2exp10(In1[13]);
   Out[14] = h2exp2(In1[14]);
   Out[15] = h2floor(In1[15]);
-//  Out[16] = h2log(In1[16]);
-//  Out[17] = h2log10(In1[17]);
+  Out[16] = h2log(In1[16]);
+  Out[17] = h2log10(In1[17]);
   Out[18] = h2log2(In1[18]);
   Out[19] = h2rcp(In1[19]);
 //  Out[20] = h2rint(In1[20]);