1/* bitstring.c -- Builtins for HSAIL bitstring instructions.
2
3   Copyright (C) 2015-2020 Free Software Foundation, Inc.
4   Contributed by Pekka Jaaskelainen <pekka.jaaskelainen@parmance.com>
5   for General Processor Tech.
6
7   Permission is hereby granted, free of charge, to any person obtaining a
8   copy of this software and associated documentation files
9   (the "Software"), to deal in the Software without restriction, including
10   without limitation the rights to use, copy, modify, merge, publish,
11   distribute, sublicense, and/or sell copies of the Software, and to
12   permit persons to whom the Software is furnished to do so, subject to
13   the following conditions:
14
15   The above copyright notice and this permission notice shall be included
16   in all copies or substantial portions of the Software.
17
18   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
19   OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20   MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
21   IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
22   DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
23   OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
24   USE OR OTHER DEALINGS IN THE SOFTWARE.
25*/
26
27#include <stdint.h>
28#include <limits.h>
29
30#define BITEXTRACT(DEST_TYPE, SRC0, SRC1, SRC2)				\
31  uint32_t offset = SRC1 & (sizeof (DEST_TYPE) * 8 - 1);		\
32  uint32_t width = SRC2 & (sizeof (DEST_TYPE) * 8 - 1);			\
33  if (width == 0)							\
34    return 0;								\
35  else									\
36    return (SRC0 << (sizeof (DEST_TYPE) * 8 - width - offset))		\
37      >> (sizeof (DEST_TYPE) * 8 - width)
38
39uint32_t
40__hsail_bitextract_u32 (uint32_t src0, uint32_t src1, uint32_t src2)
41{
42  BITEXTRACT (uint32_t, src0, src1, src2);
43}
44
45int32_t
46__hsail_bitextract_s32 (int32_t src0, uint32_t src1, uint32_t src2)
47{
48  BITEXTRACT (int32_t, src0, src1, src2);
49}
50
51uint64_t
52__hsail_bitextract_u64 (uint64_t src0, uint32_t src1, uint32_t src2)
53{
54  BITEXTRACT (uint64_t, src0, src1, src2);
55}
56
57int64_t
58__hsail_bitextract_s64 (int64_t src0, uint32_t src1, uint32_t src2)
59{
60  BITEXTRACT (int64_t, src0, src1, src2);
61}
62
63#define BITINSERT(DEST_TYPE, SRC0, SRC1, SRC2, SRC3)			\
64  uint32_t offset = SRC2 & (sizeof (DEST_TYPE) * 8 - 1);		\
65  uint32_t width = SRC3 & (sizeof (DEST_TYPE) * 8 - 1);			\
66  DEST_TYPE mask = ((DEST_TYPE) 1 << width) - 1;			\
67  return (SRC0 & ~(mask << offset)) | ((SRC1 & mask) << offset)
68
69uint32_t
70__hsail_bitinsert_u32 (uint32_t src0, uint32_t src1, uint32_t src2,
71			      uint32_t src3)
72{
73  BITINSERT (uint32_t, src0, src1, src2, src3);
74}
75
76int64_t
77__hsail_bitinsert_u64 (uint64_t src0, uint64_t src1, uint32_t src2,
78			      uint32_t src3)
79{
80  BITINSERT (uint64_t, src0, src1, src2, src3);
81}
82
83#define BITMASK(DEST_TYPE, SRC0, SRC1)					\
84  uint32_t offset = SRC0 & (sizeof (DEST_TYPE) * 8 - 1);		\
85  uint32_t width = SRC1 & (sizeof (DEST_TYPE) * 8 - 1);			\
86  DEST_TYPE mask = ((DEST_TYPE) 1 << width) - 1;			\
87  return mask << offset
88
89uint32_t
90__hsail_bitmask_u32 (uint32_t src0, uint32_t src1)
91{
92  BITMASK (uint32_t, src0, src1);
93}
94
95uint64_t
96__hsail_bitmask_u64 (uint32_t src0, uint32_t src1)
97{
98  BITMASK (uint64_t, src0, src1);
99}
100
101/* The dummy, but readable version from
102   http://graphics.stanford.edu/~seander/bithacks.html#BitReverseObvious
103   This (also) often maps to a single instruction in DSPs.  */
104
105#define BITREV(DEST_TYPE, SRC)						\
106  DEST_TYPE v = SRC;							\
107  DEST_TYPE r = v;							\
108  int s = sizeof (SRC) * CHAR_BIT - 1;					\
109  									\
110  for (v >>= 1; v; v >>= 1)						\
111    {									\
112      r <<= 1;								\
113      r |= v & 1;							\
114      s--;								\
115    }									\
116  return r << s
117
118uint32_t
119__hsail_bitrev_u32 (uint32_t src0)
120{
121  BITREV (uint32_t, src0);
122}
123
124uint64_t
125__hsail_bitrev_u64 (uint64_t src0)
126{
127  BITREV (uint64_t, src0);
128}
129
130uint32_t
131__hsail_bitselect_u32 (uint32_t src0, uint32_t src1, uint32_t src2)
132{
133  return (src1 & src0) | (src2 & ~src0);
134}
135
136uint64_t
137__hsail_bitselect_u64 (uint64_t src0, uint64_t src1, uint64_t src2)
138{
139  return (src1 & src0) | (src2 & ~src0);
140}
141
142/* Due to the defined behavior with 0, we cannot use the gcc builtin
143   __builtin_clz* () directly. __builtin_ffs () has defined behavior, but
144   returns 0 while HSAIL requires to return -1.  */
145
146uint32_t
147__hsail_firstbit_u32 (uint32_t src0)
148{
149  if (src0 == 0)
150    return -1;
151  return __builtin_clz (src0);
152}
153
154uint32_t
155__hsail_firstbit_s32 (int32_t src0)
156{
157  uint32_t converted = src0 >= 0 ? src0 : ~src0;
158  return __hsail_firstbit_u32 (converted);
159}
160
161uint32_t
162__hsail_firstbit_u64 (uint64_t src0)
163{
164  if (src0 == 0)
165    return -1;
166  return __builtin_clzl (src0);
167}
168
169uint32_t
170__hsail_firstbit_s64 (int64_t src0)
171{
172  uint64_t converted = src0 >= 0 ? src0 : ~src0;
173  return __hsail_firstbit_u64 (converted);
174}
175
176uint32_t
177__hsail_lastbit_u32 (uint32_t src0)
178{
179  if (src0 == 0)
180    return -1;
181  return __builtin_ctz (src0);
182}
183
184uint32_t
185__hsail_lastbit_u64 (uint64_t src0)
186{
187  if (src0 == 0)
188    return -1;
189  return __builtin_ctzl (src0);
190}
191