xref: /minix3/sys/external/bsd/compiler_rt/dist/lib/builtins/fp_trunc.h (revision 0a6a1f1d05b60e214de2f05a7310ddd1f0e590e7)
1*0a6a1f1dSLionel Sambuc //=== lib/fp_trunc.h - high precision -> low precision conversion *- C -*-===//
2*0a6a1f1dSLionel Sambuc //
3*0a6a1f1dSLionel Sambuc //                     The LLVM Compiler Infrastructure
4*0a6a1f1dSLionel Sambuc //
5*0a6a1f1dSLionel Sambuc // This file is dual licensed under the MIT and the University of Illinois Open
6*0a6a1f1dSLionel Sambuc // Source Licenses. See LICENSE.TXT for details.
7*0a6a1f1dSLionel Sambuc //
8*0a6a1f1dSLionel Sambuc //===----------------------------------------------------------------------===//
9*0a6a1f1dSLionel Sambuc //
10*0a6a1f1dSLionel Sambuc // Set source and destination precision setting
11*0a6a1f1dSLionel Sambuc //
12*0a6a1f1dSLionel Sambuc //===----------------------------------------------------------------------===//
13*0a6a1f1dSLionel Sambuc 
14*0a6a1f1dSLionel Sambuc #ifndef FP_TRUNC_HEADER
15*0a6a1f1dSLionel Sambuc #define FP_TRUNC_HEADER
16*0a6a1f1dSLionel Sambuc 
17*0a6a1f1dSLionel Sambuc #include "int_lib.h"
18*0a6a1f1dSLionel Sambuc 
19*0a6a1f1dSLionel Sambuc #if defined SRC_DOUBLE
20*0a6a1f1dSLionel Sambuc typedef double src_t;
21*0a6a1f1dSLionel Sambuc typedef uint64_t src_rep_t;
22*0a6a1f1dSLionel Sambuc #define SRC_REP_C UINT64_C
23*0a6a1f1dSLionel Sambuc static const int srcSigBits = 52;
24*0a6a1f1dSLionel Sambuc 
25*0a6a1f1dSLionel Sambuc #elif defined SRC_QUAD
26*0a6a1f1dSLionel Sambuc typedef long double src_t;
27*0a6a1f1dSLionel Sambuc typedef __uint128_t src_rep_t;
28*0a6a1f1dSLionel Sambuc #define SRC_REP_C (__uint128_t)
29*0a6a1f1dSLionel Sambuc static const int srcSigBits = 112;
30*0a6a1f1dSLionel Sambuc 
31*0a6a1f1dSLionel Sambuc #else
32*0a6a1f1dSLionel Sambuc #error Source should be double precision or quad precision!
33*0a6a1f1dSLionel Sambuc #endif //end source precision
34*0a6a1f1dSLionel Sambuc 
35*0a6a1f1dSLionel Sambuc #if defined DST_DOUBLE
36*0a6a1f1dSLionel Sambuc typedef double dst_t;
37*0a6a1f1dSLionel Sambuc typedef uint64_t dst_rep_t;
38*0a6a1f1dSLionel Sambuc #define DST_REP_C UINT64_C
39*0a6a1f1dSLionel Sambuc static const int dstSigBits = 52;
40*0a6a1f1dSLionel Sambuc 
41*0a6a1f1dSLionel Sambuc #elif defined DST_SINGLE
42*0a6a1f1dSLionel Sambuc typedef float dst_t;
43*0a6a1f1dSLionel Sambuc typedef uint32_t dst_rep_t;
44*0a6a1f1dSLionel Sambuc #define DST_REP_C UINT32_C
45*0a6a1f1dSLionel Sambuc static const int dstSigBits = 23;
46*0a6a1f1dSLionel Sambuc 
47*0a6a1f1dSLionel Sambuc #else
48*0a6a1f1dSLionel Sambuc #error Destination should be single precision or double precision!
49*0a6a1f1dSLionel Sambuc #endif //end destination precision
50*0a6a1f1dSLionel Sambuc 
51*0a6a1f1dSLionel Sambuc // End of specialization parameters.  Two helper routines for conversion to and
52*0a6a1f1dSLionel Sambuc // from the representation of floating-point data as integer values follow.
53*0a6a1f1dSLionel Sambuc 
srcToRep(src_t x)54*0a6a1f1dSLionel Sambuc static inline src_rep_t srcToRep(src_t x) {
55*0a6a1f1dSLionel Sambuc     const union { src_t f; src_rep_t i; } rep = {.f = x};
56*0a6a1f1dSLionel Sambuc     return rep.i;
57*0a6a1f1dSLionel Sambuc }
58*0a6a1f1dSLionel Sambuc 
dstFromRep(dst_rep_t x)59*0a6a1f1dSLionel Sambuc static inline dst_t dstFromRep(dst_rep_t x) {
60*0a6a1f1dSLionel Sambuc     const union { dst_t f; dst_rep_t i; } rep = {.i = x};
61*0a6a1f1dSLionel Sambuc     return rep.f;
62*0a6a1f1dSLionel Sambuc }
63*0a6a1f1dSLionel Sambuc 
64*0a6a1f1dSLionel Sambuc #endif // FP_TRUNC_HEADER
65