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_DOUBLE
20 typedef double src_t;
21 typedef uint64_t src_rep_t;
22 #define SRC_REP_C UINT64_C
23 static const int srcSigBits = 52;
24 
25 #elif defined SRC_QUAD
26 typedef long double src_t;
27 typedef __uint128_t src_rep_t;
28 #define SRC_REP_C (__uint128_t)
29 static const int srcSigBits = 112;
30 
31 #else
32 #error Source should be double precision or quad precision!
33 #endif //end source precision
34 
35 #if defined DST_DOUBLE
36 typedef double dst_t;
37 typedef uint64_t dst_rep_t;
38 #define DST_REP_C UINT64_C
39 static const int dstSigBits = 52;
40 
41 #elif defined DST_SINGLE
42 typedef float dst_t;
43 typedef uint32_t dst_rep_t;
44 #define DST_REP_C UINT32_C
45 static const int dstSigBits = 23;
46 
47 #else
48 #error Destination should be single precision or double precision!
49 #endif //end destination precision
50 
51 // End of specialization parameters.  Two helper routines for conversion to and
52 // from the representation of floating-point data as integer values follow.
53 
srcToRep(src_t x)54 static inline src_rep_t srcToRep(src_t x) {
55     const union { src_t f; src_rep_t i; } rep = {.f = x};
56     return rep.i;
57 }
58 
dstFromRep(dst_rep_t x)59 static inline dst_t dstFromRep(dst_rep_t x) {
60     const union { dst_t f; dst_rep_t i; } rep = {.i = x};
61     return rep.f;
62 }
63 
64 #endif // FP_TRUNC_HEADER
65