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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;
src_rep_t_clz(src_rep_t a)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 
srcToRep(src_t x)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 
dstFromRep(dst_rep_t x)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
77