src/compiler-rt/lib/builtins/fp_trunc.h

   1 //=== lib/fp_trunc.h - high precision -> low 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 precision setting
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #ifndef FP_TRUNC_HEADER
  15 #define FP_TRUNC_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
  25 #elif defined SRC_DOUBLE
  26 typedef double src_t;
  27 typedef uint64_t src_rep_t;
  28 #define SRC_REP_C UINT64_C
  29 static const int srcSigBits = 52;
  30
  31 #elif defined SRC_QUAD
  32 typedef long double src_t;
  33 typedef __uint128_t src_rep_t;
  34 #define SRC_REP_C (__uint128_t)
  35 static const int srcSigBits = 112;
  36
  37 #else
  38 #error Source should be double precision or quad precision!
  39 #endif //end source precision
  40
  41 #if defined DST_DOUBLE
  42 typedef double dst_t;
  43 typedef uint64_t dst_rep_t;
  44 #define DST_REP_C UINT64_C
  45 static const int dstSigBits = 52;
  46
  47 #elif defined DST_SINGLE
  48 typedef float dst_t;
  49 typedef uint32_t dst_rep_t;
  50 #define DST_REP_C UINT32_C
  51 static const int dstSigBits = 23;
  52
  53 #elif defined DST_HALF
  54 typedef uint16_t dst_t;
  55 typedef uint16_t dst_rep_t;
  56 #define DST_REP_C UINT16_C
  57 static const int dstSigBits = 10;
  58
  59 #else
  60 #error Destination should be single precision or double precision!
  61 #endif //end destination precision
  62
  63 // End of specialization parameters.  Two helper routines for conversion to and
  64 // from the representation of floating-point data as integer values follow.
  65
  66 static __inline src_rep_t srcToRep(src_t x) {
  67     const union { src_t f; src_rep_t i; } rep = {.f = x};
  68     return rep.i;
  69 }
  70
  71 static __inline dst_t dstFromRep(dst_rep_t x) {
  72     const union { dst_t f; dst_rep_t i; } rep = {.i = x};
  73     return rep.f;
  74 }
  75
  76 #endif // FP_TRUNC_HEADER