[libclc] Don't rely on fp16 pragma guards in headers (llvm#122751)

Having the fp16 pragmas enabled in the header file is risky. The macros
defined by that header don't (and can't) include the pragmas that make
fp16 types themselves legal, and another header may disable the fp16
pragma before the macro's use.

The safest thing to do is the use of pragmas surrounding each use of the
macro in the implementation files. This pattern is also far more common
across the codebase.

Author: frasercrmck

libclc/clc/include/clc/clcmacro.h

@@ -227,6 +227,8 @@
   }                                                                            \
   _CLC_BINARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, half, FUNCTION, half, half)
 
+#pragma OPENCL EXTENSION cl_khr_fp16 : disable
+
 #else
 
 #define _CLC_DEFINE_UNARY_BUILTIN_FP16(FUNCTION)

libclc/generic/lib/math/acos.cl

@@ -172,4 +172,10 @@ _CLC_UNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, double, acos, double);
 
 #endif // cl_khr_fp64
 
+#ifdef cl_khr_fp16
+
+#pragma OPENCL EXTENSION cl_khr_fp16 : enable
+
 _CLC_DEFINE_UNARY_BUILTIN_FP16(acos)
+
+#endif

libclc/generic/lib/math/acosh.cl

@@ -126,4 +126,10 @@ _CLC_UNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, double, acosh, double)
 
 #endif
 
+#ifdef cl_khr_fp16
+
+#pragma OPENCL EXTENSION cl_khr_fp16 : enable
+
 _CLC_DEFINE_UNARY_BUILTIN_FP16(acosh)
+
+#endif

libclc/generic/lib/math/acospi.cl

@@ -171,4 +171,10 @@ _CLC_UNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, double, acospi, double)
 
 #endif
 
+#ifdef cl_khr_fp16
+
+#pragma OPENCL EXTENSION cl_khr_fp16 : enable
+
 _CLC_DEFINE_UNARY_BUILTIN_FP16(acospi)
+
+#endif

libclc/generic/lib/math/asinh.cl

@@ -292,4 +292,10 @@ _CLC_UNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, double, asinh, double)
 
 #endif
 
+#ifdef cl_khr_fp16
+
+#pragma OPENCL EXTENSION cl_khr_fp16 : enable
+
 _CLC_DEFINE_UNARY_BUILTIN_FP16(asinh)
+
+#endif

libclc/generic/lib/math/atan.cl

@@ -182,5 +182,10 @@ _CLC_UNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, double, atan, double);
 
 #endif // cl_khr_fp64
 
+#ifdef cl_khr_fp16
+
+#pragma OPENCL EXTENSION cl_khr_fp16 : enable
 
 _CLC_DEFINE_UNARY_BUILTIN_FP16(atan)
+
+#endif

libclc/generic/lib/math/atan2.cl

@@ -236,4 +236,10 @@ _CLC_BINARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, double, atan2, double, double);
 
 #endif
 
+#ifdef cl_khr_fp16
+
+#pragma OPENCL EXTENSION cl_khr_fp16 : enable
+
 _CLC_DEFINE_BINARY_BUILTIN_FP16(atan2)
+
+#endif

libclc/generic/lib/math/atan2pi.cl

@@ -220,4 +220,10 @@ _CLC_BINARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, double, atan2pi, double, double)
 
 #endif
 
+#ifdef cl_khr_fp16
+
+#pragma OPENCL EXTENSION cl_khr_fp16 : enable
+
 _CLC_DEFINE_BINARY_BUILTIN_FP16(atan2pi)
+
+#endif

libclc/generic/lib/math/atanh.cl

@@ -112,4 +112,10 @@ _CLC_UNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, double, atanh, double)
 
 #endif
 
+#ifdef cl_khr_fp16
+
+#pragma OPENCL EXTENSION cl_khr_fp16 : enable
+
 _CLC_DEFINE_UNARY_BUILTIN_FP16(atanh)
+
+#endif

libclc/generic/lib/math/atanpi.cl

@@ -181,4 +181,10 @@ _CLC_UNARY_VECTORIZE(_CLC_OVERLOAD _CLC_DEF, double, atanpi, double)
 
 #endif
 
+#ifdef cl_khr_fp16
+
+#pragma OPENCL EXTENSION cl_khr_fp16 : enable
+
 _CLC_DEFINE_UNARY_BUILTIN_FP16(atanpi)
+
+#endif