Utest: Move half related helper function into utest helper

For more half related tests, need to use helper funciton in utest.

Signed-off-by: Pan Xiuli <xiuli.pan@intel.com>
Reviewed-by: Yang Rong <rong.r.yang@intel.com>

1 files changed, 119 insertions, 0 deletions

diff --git a/utests/utest_helper.cpp b/utests/utest_helper.cpp
index 3388d9fc..5a2ac6e6 100644
--- a/utests/utest_helper.cpp
+++ b/utests/utest_helper.cpp
@@ -28,6 +28,7 @@
 #include <cstring>
 #include <cassert>
 #include <cmath>
+#include <algorithm>
 
 #define FATAL(...) \
 do { \
@@ -927,3 +928,121 @@ int cl_check_ocl20(void)
   free(device_version_str);
   return 1;
 }
+
+int cl_check_half(void)
+{
+  std::string extStr;
+  size_t param_value_size;
+  OCL_CALL(clGetDeviceInfo, device, CL_DEVICE_EXTENSIONS, 0, 0, &param_value_size);
+  std::vector<char> param_value(param_value_size);
+  OCL_CALL(clGetDeviceInfo, device, CL_DEVICE_EXTENSIONS, param_value_size,
+           param_value.empty() ? NULL : &param_value.front(), &param_value_size);
+  if (!param_value.empty())
+    extStr = std::string(&param_value.front(), param_value_size-1);
+
+  if (std::strstr(extStr.c_str(), "cl_khr_fp16") == NULL) {
+    printf("No cl_khr_fp16, Skip!");
+    return 0;
+  }
+
+  return 1;
+}
+
+uint32_t __half_to_float(uint16_t h, bool* isInf, bool* infSign)
+{
+  struct __FP32 {
+    uint32_t mantissa:23;
+    uint32_t exponent:8;
+    uint32_t sign:1;
+  };
+  struct __FP16 {
+    uint32_t mantissa:10;
+    uint32_t exponent:5;
+    uint32_t sign:1;
+  };
+  uint32_t f;
+  __FP32 o;
+  memset(&o, 0, sizeof(o));
+  __FP16 i;
+  memcpy(&i, &h, sizeof(uint16_t));
+
+  if (isInf)
+    *isInf = false;
+  if (infSign)
+    *infSign = false;
+
+  if (i.exponent == 0 && i.mantissa == 0) // (Signed) zero
+    o.sign = i.sign;
+  else {
+    if (i.exponent == 0) { // Denormal (converts to normalized)
+      // Adjust mantissa so it's normalized (and keep
+      // track of exponent adjustment)
+      int e = -1;
+      uint m = i.mantissa;
+      do {
+        e++;
+        m <<= 1;
+      } while ((m & 0x400) == 0);
+
+      o.mantissa = (m & 0x3ff) << 13;
+      o.exponent = 127 - 15 - e;
+      o.sign = i.sign;
+    } else if (i.exponent == 0x1f) { // Inf/NaN
+      // NOTE: Both can be handled with same code path
+      // since we just pass through mantissa bits.
+      o.mantissa = i.mantissa << 13;
+      o.exponent = 255;
+      o.sign = i.sign;
+
+      if (isInf) {
+        *isInf = (i.mantissa == 0);
+        if (infSign)
+          *infSign = !i.sign;
+      }
+    } else { // Normalized number
+      o.mantissa = i.mantissa << 13;
+      o.exponent = 127 - 15 + i.exponent;
+      o.sign = i.sign;
+    }
+  }
+
+  memcpy(&f, &o, sizeof(uint32_t));
+  return f;
+}
+
+
+uint16_t __float_to_half(uint32_t x)
+{
+  uint16_t bits = (x >> 16) & 0x8000; /* Get the sign */
+  uint16_t m = (x >> 12) & 0x07ff; /* Keep one extra bit for rounding */
+  unsigned int e = (x >> 23) & 0xff; /* Using int is faster here */
+
+  /* If zero, or denormal, or exponent underflows too much for a denormal
+   * half, return signed zero. */
+  if (e < 103)
+    return bits;
+
+  /* If NaN, return NaN. If Inf or exponent overflow, return Inf. */
+  if (e > 142) {
+    bits |= 0x7c00u;
+    /* If exponent was 0xff and one mantissa bit was set, it means NaN,
+     * not Inf, so make sure we set one mantissa bit too. */
+    bits |= e == 255 && (x & 0x007fffffu);
+    return bits;
+  }
+
+  /* If exponent underflows but not too much, return a denormal */
+  if (e < 113) {
+    m |= 0x0800u;
+    /* Extra rounding may overflow and set mantissa to 0 and exponent
+     * to 1, which is OK. */
+    bits |= (m >> (114 - e)) + ((m >> (113 - e)) & 1);
+    return bits;
+  }
+
+  bits |= ((e - 112) << 10) | (m >> 1);
+  /* Extra rounding. An overflow will set mantissa to 0 and increment
+   * the exponent, which is OK. */
+  bits += m & 1;
+  return bits;
+}