util/bitpack_helpers: Make fixed packs CL safe

We emulate roundf and llroundf for compatibility.

Signed-off-by: Mary Guillemard <mary.guillemard@collabora.com>
Acked-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Reviewed-by: Eric R. Smith <eric.smith@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/32939>

src/compiler/libcl/libcl.h

@@ -210,6 +210,19 @@ uif(uint32_t ui)
    return as_float(ui);
 }
 
+#define CL_FLT_EPSILON 1.1920928955078125e-7f
+
+/* OpenCL C lacks roundf and llroundf, we can emulate it */
+static inline float roundf(float x)
+{
+   return trunc(x + copysign(0.5f - 0.25f * CL_FLT_EPSILON, x));
+}
+
+static inline long long llroundf(float x)
+{
+   return roundf(x);
+}
+
 static inline uint16_t
 _mesa_float_to_half(float f)
 {

src/util/bitpack_helpers.h

@@ -119,7 +119,6 @@ util_bitpack_float_nonzero(float v)
    return util_bitpack_float(v);
 }
 
-#ifndef __OPENCL_VERSION__
 ALWAYS_INLINE static uint64_t
 util_bitpack_sfixed(float v, uint32_t start, uint32_t end,
                     uint32_t fract_bits)
@@ -211,6 +210,5 @@ util_bitpack_ufixed_nonzero(float v, uint32_t start, uint32_t end,
    assert(v != 0.0f);
    return util_bitpack_ufixed(v, start, end, fract_bits);
 }
-#endif
 
 #endif /* UTIL_BITPACK_HELPERS_H */