SWDEV-571222 - Fix bf16 headers on gcc (#2260)

GCC does not support anonymous structs with members that have non-trivial constructors. This commit changes the header to remove the union when compiling with gcc. This should be a non-breaking change for other compilers.

projects/clr/hipamd/include/hip/amd_detail/amd_hip_bf16.h

@@ -111,9 +111,8 @@
 #if !defined(__HIPCC_RTC__)
 #include <hip/amd_detail/amd_hip_common.h>
 #include "amd_hip_vector_types.h"  // float2 etc
-#include "device_library_decls.h"  // ocml conversion functions
-#include "math_fwd.h"              // ocml device functions
 #if defined(__clang__) && defined(__HIP__)
+#include "math_fwd.h"              // ocml device functions
 #include <hip/amd_detail/amd_warp_functions.h>       // define warpSize
 #include <hip/amd_detail/amd_warp_sync_functions.h>  // Sync functions
 #endif
@@ -338,7 +337,11 @@ struct __attribute__((aligned(2))) __hip_bfloat16 {
 };
 /**@}*/
 
+#if defined(__clang__)
 typedef __bf16 __bf16_2 __attribute__((ext_vector_type(2)));
+#else
+typedef __bf16 __bf16_2 __attribute__((vector_size(sizeof(__bf16) * 2)));
+#endif
 
 /**
  * \defgroup HIP_INTRINSIC_BFLOAT162_STRUCT
@@ -350,6 +353,7 @@ struct __attribute__((aligned(4))) __hip_bfloat162 {
   static_assert(sizeof(__hip_bfloat16[2]) == sizeof(__bf16_2));
 
  public:
+#if defined(__clang__)
   union {
     struct {
       __hip_bfloat16 x; /*! \brief raw representation of bfloat16 */
@@ -357,7 +361,12 @@ struct __attribute__((aligned(4))) __hip_bfloat162 {
     };
     __bf16_2 __xy_bf162;
   };
-
+#else
+  /* GCC does not support anonymous structs with members that have non-trivial constructors (Clang
+  allows this as an extension). Expose x and y directly instead. */
+  __hip_bfloat16 x;
+  __hip_bfloat16 y;
+#endif
 
  public:
   /*! \brief create __hip_bfloat162 from __hip_bfloat162_raw */
@@ -373,7 +382,11 @@ struct __attribute__((aligned(4))) __hip_bfloat162 {
       : x(a), y(b) {}
 
   /*! \brief create __hip_bfloat162 from vector of __bf16_2 */
+#if defined(__clang__)
   __BF16_HOST_DEVICE__ __hip_bfloat162(const __bf16_2 in) : __xy_bf162(in) {}
+#else
+  __BF16_HOST_DEVICE__ __hip_bfloat162(const __bf16_2 in) : x{in[0]}, y{in[1]} {}
+#endif
 
   /*! \brief default constructor of __hip_bfloat162 */
   __BF16_HOST_DEVICE__ __hip_bfloat162() = default;
@@ -392,11 +405,22 @@ struct __attribute__((aligned(4))) __hip_bfloat162 {
   }
 
   /*! \brief return a vector of bf16 */
-  __BF16_HOST_DEVICE__ operator __bf16_2() const { return __xy_bf162; }
+  __BF16_HOST_DEVICE__ operator __bf16_2() const {
+#if defined(__clang__)
+    return __xy_bf162;
+#else
+    return __bf16_2{x, y};
+#endif
+  }
 
   /*! \brief return a vector of bf16 */
   __BF16_HOST_DEVICE__ __hip_bfloat162& operator=(const __bf16_2 in) {
+#if defined(__clang__)
     __xy_bf162 = in;
+#else
+    x = __hip_bfloat16{in[0]};
+    y = __hip_bfloat16{in[1]};
+#endif
     return *this;
   }
 
@@ -835,6 +859,7 @@ __BF16_HOST_DEVICE_STATIC__ __hip_bfloat16 __hdiv(const __hip_bfloat16 a, const
   return (__bf16)a / (__bf16)b;
 }
 
+#if defined(__clang__) && defined(__HIP__)
 /**
  * \ingroup HIP_INTRINSIC_BFLOAT16_ARITH
  * \brief Performs FMA of given bfloat16 values
@@ -844,6 +869,7 @@ __BF16_DEVICE_STATIC__ __hip_bfloat16 __hfma(const __hip_bfloat16 a, const __hip
   return __hip_bfloat16(__builtin_elementwise_fma(__bf16(a), __bf16(b), __bf16(c)));
   ;
 }
+#endif
 
 /**
  * \ingroup HIP_INTRINSIC_BFLOAT16_ARITH
@@ -919,6 +945,8 @@ __BF16_HOST_DEVICE_STATIC__ __hip_bfloat162 __hadd2_rn(const __hip_bfloat162 a,
   return __hip_bfloat162{__bf16_2(a) + __bf16_2(b)};
 }
 
+
+#if defined(__clang__) && defined(__HIP__)
 /**
  * \ingroup HIP_INTRINSIC_BFLOAT162_ARITH
  * \brief Performs FMA of given bfloat162 values
@@ -927,6 +955,7 @@ __BF16_DEVICE_STATIC__ __hip_bfloat162 __hfma2(const __hip_bfloat162 a, const __
                                                const __hip_bfloat162 c) {
   return __hip_bfloat162{__builtin_elementwise_fma(__bf16_2(a), __bf16_2(b), __bf16_2(c))};
 }
+#endif
 
 /**
  * \ingroup HIP_INTRINSIC_BFLOAT162_ARITH
@@ -1639,6 +1668,7 @@ __BF16_HOST_DEVICE_STATIC__ bool operator>=(const __hip_bfloat162& l, const __hi
   return fl.x >= fr.x && fl.x >= fr.y;
 }
 
+#if defined(__clang__) && defined(__HIP__)
 /**
  * \ingroup HIP_INTRINSIC_BFLOAT16_MATH
  * \brief Calculate ceil of bfloat16
@@ -1883,7 +1913,6 @@ __BF16_DEVICE_STATIC__ __hip_bfloat162 h2trunc(const __hip_bfloat162 h) {
   return __hip_bfloat162(htrunc(h.x), htrunc(h.y));
 }
 
-#if defined(__clang__) && defined(__HIP__)
 /**
  * \ingroup HIP_INTRINSIC_BFLOAT162_MATH
  * \brief Atomic add bfloat162