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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 
srcToRep(src_t x)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 
dstFromRep(dst_rep_t x)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
77