compiler-rt/lib/builtins/fp_extend.h

   1 //===-lib/fp_extend.h - low precision -> high precision conversion -*- C
   2 //-*-===//
   3 //
   4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   5 // See https://llvm.org/LICENSE.txt for license information.
   6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   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 clzsi
  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 clzsi(a >> 32);
  37   else
  38     return 32 + clzsi(a & REP_C(0xffffffff));
  39 #endif
  40 }
  41
  42 #elif defined SRC_HALF
  43 #ifdef COMPILER_RT_HAS_FLOAT16
  44 typedef _Float16 src_t;
  45 #else
  46 typedef uint16_t src_t;
  47 #endif
  48 typedef uint16_t src_rep_t;
  49 #define SRC_REP_C UINT16_C
  50 static const int srcSigBits = 10;
  51 #define src_rep_t_clz __builtin_clz
  52
  53 #else
  54 #error Source should be half, single, or double precision!
  55 #endif // end source precision
  56
  57 #if defined DST_SINGLE
  58 typedef float dst_t;
  59 typedef uint32_t dst_rep_t;
  60 #define DST_REP_C UINT32_C
  61 static const int dstSigBits = 23;
  62
  63 #elif defined DST_DOUBLE
  64 typedef double dst_t;
  65 typedef uint64_t dst_rep_t;
  66 #define DST_REP_C UINT64_C
  67 static const int dstSigBits = 52;
  68
  69 #elif defined DST_QUAD
  70 typedef long double dst_t;
  71 typedef __uint128_t dst_rep_t;
  72 #define DST_REP_C (__uint128_t)
  73 static const int dstSigBits = 112;
  74
  75 #else
  76 #error Destination should be single, double, or quad precision!
  77 #endif // end destination precision
  78
  79 // End of specialization parameters.  Two helper routines for conversion to and
  80 // from the representation of floating-point data as integer values follow.
  81
  82 static __inline src_rep_t srcToRep(src_t x) {
  83   const union {
  84     src_t f;
  85     src_rep_t i;
  86   } rep = {.f = x};
  87   return rep.i;
  88 }
  89
  90 static __inline dst_t dstFromRep(dst_rep_t x) {
  91   const union {
  92     dst_t f;
  93     dst_rep_t i;
  94   } rep = {.i = x};
  95   return rep.f;
  96 }
  97 // End helper routines.  Conversion implementation follows.
  98
  99 #endif // FP_EXTEND_HEADER