xref: /freebsd/contrib/llvm-project/compiler-rt/lib/builtins/fp_extend.h (revision 0b57cec536236d46e3dba9bd041533462f33dbb7)
1*0b57cec5SDimitry Andric //===-lib/fp_extend.h - low precision -> high precision conversion -*- C
2*0b57cec5SDimitry Andric //-*-===//
3*0b57cec5SDimitry Andric //
4*0b57cec5SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5*0b57cec5SDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
6*0b57cec5SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7*0b57cec5SDimitry Andric //
8*0b57cec5SDimitry Andric //===----------------------------------------------------------------------===//
9*0b57cec5SDimitry Andric //
10*0b57cec5SDimitry Andric // Set source and destination setting
11*0b57cec5SDimitry Andric //
12*0b57cec5SDimitry Andric //===----------------------------------------------------------------------===//
13*0b57cec5SDimitry Andric 
14*0b57cec5SDimitry Andric #ifndef FP_EXTEND_HEADER
15*0b57cec5SDimitry Andric #define FP_EXTEND_HEADER
16*0b57cec5SDimitry Andric 
17*0b57cec5SDimitry Andric #include "int_lib.h"
18*0b57cec5SDimitry Andric 
19*0b57cec5SDimitry Andric #if defined SRC_SINGLE
20*0b57cec5SDimitry Andric typedef float src_t;
21*0b57cec5SDimitry Andric typedef uint32_t src_rep_t;
22*0b57cec5SDimitry Andric #define SRC_REP_C UINT32_C
23*0b57cec5SDimitry Andric static const int srcSigBits = 23;
24*0b57cec5SDimitry Andric #define src_rep_t_clz __builtin_clz
25*0b57cec5SDimitry Andric 
26*0b57cec5SDimitry Andric #elif defined SRC_DOUBLE
27*0b57cec5SDimitry Andric typedef double src_t;
28*0b57cec5SDimitry Andric typedef uint64_t src_rep_t;
29*0b57cec5SDimitry Andric #define SRC_REP_C UINT64_C
30*0b57cec5SDimitry Andric static const int srcSigBits = 52;
31*0b57cec5SDimitry Andric static __inline int src_rep_t_clz(src_rep_t a) {
32*0b57cec5SDimitry Andric #if defined __LP64__
33*0b57cec5SDimitry Andric   return __builtin_clzl(a);
34*0b57cec5SDimitry Andric #else
35*0b57cec5SDimitry Andric   if (a & REP_C(0xffffffff00000000))
36*0b57cec5SDimitry Andric     return __builtin_clz(a >> 32);
37*0b57cec5SDimitry Andric   else
38*0b57cec5SDimitry Andric     return 32 + __builtin_clz(a & REP_C(0xffffffff));
39*0b57cec5SDimitry Andric #endif
40*0b57cec5SDimitry Andric }
41*0b57cec5SDimitry Andric 
42*0b57cec5SDimitry Andric #elif defined SRC_HALF
43*0b57cec5SDimitry Andric typedef uint16_t src_t;
44*0b57cec5SDimitry Andric typedef uint16_t src_rep_t;
45*0b57cec5SDimitry Andric #define SRC_REP_C UINT16_C
46*0b57cec5SDimitry Andric static const int srcSigBits = 10;
47*0b57cec5SDimitry Andric #define src_rep_t_clz __builtin_clz
48*0b57cec5SDimitry Andric 
49*0b57cec5SDimitry Andric #else
50*0b57cec5SDimitry Andric #error Source should be half, single, or double precision!
51*0b57cec5SDimitry Andric #endif // end source precision
52*0b57cec5SDimitry Andric 
53*0b57cec5SDimitry Andric #if defined DST_SINGLE
54*0b57cec5SDimitry Andric typedef float dst_t;
55*0b57cec5SDimitry Andric typedef uint32_t dst_rep_t;
56*0b57cec5SDimitry Andric #define DST_REP_C UINT32_C
57*0b57cec5SDimitry Andric static const int dstSigBits = 23;
58*0b57cec5SDimitry Andric 
59*0b57cec5SDimitry Andric #elif defined DST_DOUBLE
60*0b57cec5SDimitry Andric typedef double dst_t;
61*0b57cec5SDimitry Andric typedef uint64_t dst_rep_t;
62*0b57cec5SDimitry Andric #define DST_REP_C UINT64_C
63*0b57cec5SDimitry Andric static const int dstSigBits = 52;
64*0b57cec5SDimitry Andric 
65*0b57cec5SDimitry Andric #elif defined DST_QUAD
66*0b57cec5SDimitry Andric typedef long double dst_t;
67*0b57cec5SDimitry Andric typedef __uint128_t dst_rep_t;
68*0b57cec5SDimitry Andric #define DST_REP_C (__uint128_t)
69*0b57cec5SDimitry Andric static const int dstSigBits = 112;
70*0b57cec5SDimitry Andric 
71*0b57cec5SDimitry Andric #else
72*0b57cec5SDimitry Andric #error Destination should be single, double, or quad precision!
73*0b57cec5SDimitry Andric #endif // end destination precision
74*0b57cec5SDimitry Andric 
75*0b57cec5SDimitry Andric // End of specialization parameters.  Two helper routines for conversion to and
76*0b57cec5SDimitry Andric // from the representation of floating-point data as integer values follow.
77*0b57cec5SDimitry Andric 
78*0b57cec5SDimitry Andric static __inline src_rep_t srcToRep(src_t x) {
79*0b57cec5SDimitry Andric   const union {
80*0b57cec5SDimitry Andric     src_t f;
81*0b57cec5SDimitry Andric     src_rep_t i;
82*0b57cec5SDimitry Andric   } rep = {.f = x};
83*0b57cec5SDimitry Andric   return rep.i;
84*0b57cec5SDimitry Andric }
85*0b57cec5SDimitry Andric 
86*0b57cec5SDimitry Andric static __inline dst_t dstFromRep(dst_rep_t x) {
87*0b57cec5SDimitry Andric   const union {
88*0b57cec5SDimitry Andric     dst_t f;
89*0b57cec5SDimitry Andric     dst_rep_t i;
90*0b57cec5SDimitry Andric   } rep = {.i = x};
91*0b57cec5SDimitry Andric   return rep.f;
92*0b57cec5SDimitry Andric }
93*0b57cec5SDimitry Andric // End helper routines.  Conversion implementation follows.
94*0b57cec5SDimitry Andric 
95*0b57cec5SDimitry Andric #endif // FP_EXTEND_HEADER
96