lib/builtins/fp_extend.h

   1 //===-lib/fp_extend.h - low precision -> high precision conversion -*- C -*-===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is dual licensed under the MIT and the University of Illinois Open
   6 // Source Licenses. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // Set source and destination setting
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #ifndef FP_EXTEND_HEADER
  15 #define FP_EXTEND_HEADER
  16
  17 #include "int_lib.h"
  18
  19 #if defined SRC_SINGLE
  20 typedef float src_t;
  21 typedef uint32_t src_rep_t;
  22 #define SRC_REP_C UINT32_C
  23 static const int srcSigBits = 23;
  24 #define src_rep_t_clz __builtin_clz
  25
  26 #elif defined SRC_DOUBLE
  27 typedef double src_t;
  28 typedef uint64_t src_rep_t;
  29 #define SRC_REP_C UINT64_C
  30 static const int srcSigBits = 52;
  31 static inline int src_rep_t_clz(src_rep_t a) {
  32 #if defined __LP64__
  33     return __builtin_clzl(a);
  34 #else
  35     if (a & REP_C(0xffffffff00000000))
  36         return __builtin_clz(a >> 32);
  37     else
  38         return 32 + __builtin_clz(a & REP_C(0xffffffff));
  39 #endif
  40 }
  41
  42 #else
  43 #error Source should be single precision or double precision!
  44 #endif //end source precision
  45
  46 #if defined DST_DOUBLE
  47 typedef double dst_t;
  48 typedef uint64_t dst_rep_t;
  49 #define DST_REP_C UINT64_C
  50 static const int dstSigBits = 52;
  51
  52 #elif defined DST_QUAD
  53 typedef long double dst_t;
  54 typedef __uint128_t dst_rep_t;
  55 #define DST_REP_C (__uint128_t)
  56 static const int dstSigBits = 112;
  57
  58 #else
  59 #error Destination should be double precision or quad precision!
  60 #endif //end destination precision
  61
  62 // End of specialization parameters.  Two helper routines for conversion to and
  63 // from the representation of floating-point data as integer values follow.
  64
  65 static inline src_rep_t srcToRep(src_t x) {
  66     const union { src_t f; src_rep_t i; } rep = {.f = x};
  67     return rep.i;
  68 }
  69
  70 static inline dst_t dstFromRep(dst_rep_t x) {
  71     const union { dst_t f; dst_rep_t i; } rep = {.i = x};
  72     return rep.f;
  73 }
  74 // End helper routines.  Conversion implementation follows.
  75
  76 #endif //FP_EXTEND_HEADER