WIP: Builtins: Start adding half versions of math builtins

[arsenm]

Summary

The implementation of the OpenCL builtin currently library uses 2 different hacks to get to the corresponding IR intrinsics from the source. This will allow removal of those.

I'm not sure this is the right naming scheme, but tries to follow the
single character suffix like f/l. This is a problem for sin/cos, since
__builtin_sinh already means double sinh etc. Another alternative might be _f16

[rjmccall]

In N2405 (http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2405.pdf), these are called truncf16, cosf16, etc., which I think is appropriate.

[arsenm]

Change naming scheme, add more and tests

[rjmccall]

LGTM

[arsenm]

r367973

include/clang/Basic/Builtins.def

 BUILTIN(__builtin_atanhf, "ff", "Fne")
 BUILTIN(__builtin_atanhl, "LdLd", "Fne")
 BUILTIN(__builtin_cbrt , "dd", "Fnc")
 BUILTIN(__builtin_cbrtf, "ff", "Fnc")
 BUILTIN(__builtin_cbrtl, "LdLd", "Fnc")
 BUILTIN(__builtin_ceil , "dd"  , "Fnc")
 BUILTIN(__builtin_ceilf, "ff"  , "Fnc")
 BUILTIN(__builtin_ceill, "LdLd", "Fnc")
+BUILTIN(__builtin_ceilh, "hh"  , "Fnc")
 BUILTIN(__builtin_cos , "dd"  , "Fne")
 BUILTIN(__builtin_cosf, "ff"  , "Fne")
 BUILTIN(__builtin_cosh , "dd"  , "Fne")
 BUILTIN(__builtin_coshf, "ff"  , "Fne")
 BUILTIN(__builtin_coshl, "LdLd", "Fne")
 BUILTIN(__builtin_cosl, "LdLd", "Fne")
 BUILTIN(__builtin_erf , "dd", "Fne")
 BUILTIN(__builtin_erff, "ff", "Fne")

 BUILTIN(__builtin_expm1f, "ff", "Fne")
 BUILTIN(__builtin_expm1l, "LdLd", "Fne")
 BUILTIN(__builtin_fdim, "ddd", "Fne")
 BUILTIN(__builtin_fdimf, "fff", "Fne")
 BUILTIN(__builtin_fdiml, "LdLdLd", "Fne")
 BUILTIN(__builtin_floor , "dd"  , "Fnc")
 BUILTIN(__builtin_floorf, "ff"  , "Fnc")
 BUILTIN(__builtin_floorl, "LdLd", "Fnc")
+BUILTIN(__builtin_floorh, "hh"  , "Fnc")
 BUILTIN(__builtin_fma, "dddd", "Fne")
 BUILTIN(__builtin_fmaf, "ffff", "Fne")
 BUILTIN(__builtin_fmal, "LdLdLdLd", "Fne")
+BUILTIN(__builtin_fmah, "hhhh", "Fne")
 BUILTIN(__builtin_fmax, "ddd", "Fnc")
 BUILTIN(__builtin_fmaxf, "fff", "Fnc")
 BUILTIN(__builtin_fmaxl, "LdLdLd", "Fnc")
+BUILTIN(__builtin_fmaxf, "hhh", "Fnc")
 BUILTIN(__builtin_fmin, "ddd", "Fnc")
 BUILTIN(__builtin_fminf, "fff", "Fnc")
 BUILTIN(__builtin_fminl, "LdLdLd", "Fnc")
+BUILTIN(__builtin_fminh, "hhh", "Fnc")
 BUILTIN(__builtin_hypot , "ddd"  , "Fne")
 BUILTIN(__builtin_hypotf, "fff"  , "Fne")
 BUILTIN(__builtin_hypotl, "LdLdLd", "Fne")
 BUILTIN(__builtin_ilogb , "id", "Fne")
 BUILTIN(__builtin_ilogbf, "if", "Fne")
 BUILTIN(__builtin_ilogbl, "iLd", "Fne")
 BUILTIN(__builtin_lgamma , "dd", "Fn")
 BUILTIN(__builtin_lgammaf, "ff", "Fn")

 BUILTIN(__builtin_remainderf, "fff", "Fne")
 BUILTIN(__builtin_remainderl, "LdLdLd", "Fne")
 BUILTIN(__builtin_remquo , "dddi*", "Fn")
 BUILTIN(__builtin_remquof, "fffi*", "Fn")
 BUILTIN(__builtin_remquol, "LdLdLdi*", "Fn")
 BUILTIN(__builtin_rint , "dd", "Fnc")
 BUILTIN(__builtin_rintf, "ff", "Fnc")
 BUILTIN(__builtin_rintl, "LdLd", "Fnc")
+BUILTIN(__builtin_rinth, "hh", "Fnc")
 BUILTIN(__builtin_round, "dd"  , "Fnc")
 BUILTIN(__builtin_roundf, "ff"  , "Fnc")
 BUILTIN(__builtin_roundl, "LdLd"  , "Fnc")
 BUILTIN(__builtin_scalbln , "ddLi", "Fne")
 BUILTIN(__builtin_scalblnf, "ffLi", "Fne")
 BUILTIN(__builtin_scalblnl, "LdLdLi", "Fne")
 BUILTIN(__builtin_scalbn , "ddi", "Fne")
 BUILTIN(__builtin_scalbnf, "ffi", "Fne")
 BUILTIN(__builtin_scalbnl, "LdLdi", "Fne")
 BUILTIN(__builtin_sin , "dd"  , "Fne")
 BUILTIN(__builtin_sinf, "ff"  , "Fne")
 BUILTIN(__builtin_sinh , "dd"  , "Fne")
 BUILTIN(__builtin_sinhf, "ff"  , "Fne")
 BUILTIN(__builtin_sinhl, "LdLd", "Fne")
 BUILTIN(__builtin_sinl, "LdLd", "Fne")
 BUILTIN(__builtin_sqrt , "dd"  , "Fne")
 BUILTIN(__builtin_sqrtf, "ff"  , "Fne")
 BUILTIN(__builtin_sqrtl, "LdLd", "Fne")
+BUILTIN(__builtin_sqrth, "ff"  , "Fne")
 BUILTIN(__builtin_tan , "dd"  , "Fne")
 BUILTIN(__builtin_tanf, "ff"  , "Fne")
 BUILTIN(__builtin_tanh , "dd"  , "Fne")
 BUILTIN(__builtin_tanhf, "ff"  , "Fne")
 BUILTIN(__builtin_tanhl, "LdLd", "Fne")
 BUILTIN(__builtin_tanl, "LdLd", "Fne")
 BUILTIN(__builtin_tgamma , "dd", "Fne")
 BUILTIN(__builtin_tgammaf, "ff", "Fne")
 BUILTIN(__builtin_tgammal, "LdLd", "Fne")
 BUILTIN(__builtin_trunc , "dd", "Fnc")
 BUILTIN(__builtin_truncf, "ff", "Fnc")
 BUILTIN(__builtin_truncl, "LdLd", "Fnc")
+BUILTIN(__builtin_trunch, "hh", "Fnc")
 
 // C99 complex builtins
 BUILTIN(__builtin_cabs, "dXd", "Fne")
 BUILTIN(__builtin_cabsf, "fXf", "Fne")
 BUILTIN(__builtin_cabsl, "LdXLd", "Fne")
 BUILTIN(__builtin_cacos, "XdXd", "Fne")
 BUILTIN(__builtin_cacosf, "XfXf", "Fne")
 BUILTIN(__builtin_cacosh, "XdXd", "Fne")

 BUILTIN(__builtin_signbit, "i.", "Fnc")
 BUILTIN(__builtin_signbitf, "if", "Fnc")
 BUILTIN(__builtin_signbitl, "iLd", "Fnc")
 
 // Special FP builtins.
 BUILTIN(__builtin_canonicalize, "dd", "nc")
 BUILTIN(__builtin_canonicalizef, "ff", "nc")
 BUILTIN(__builtin_canonicalizel, "LdLd", "nc")
+BUILTIN(__builtin_canonicalizeh, "hh", "nc")
 
 // Builtins for arithmetic.
 BUILTIN(__builtin_clzs , "iUs"  , "nc")
 BUILTIN(__builtin_clz  , "iUi"  , "nc")
 BUILTIN(__builtin_clzl , "iULi" , "nc")
 BUILTIN(__builtin_clzll, "iULLi", "nc")
 // TODO: int clzimax(uintmax_t)
 BUILTIN(__builtin_ctzs , "iUs"  , "nc")