xref: /openbmc/qemu/target/riscv/bitmanip_helper.c (revision 40f23e4e)
1 /*
2  * RISC-V Bitmanip Extension Helpers for QEMU.
3  *
4  * Copyright (c) 2020 Kito Cheng, kito.cheng@sifive.com
5  * Copyright (c) 2020 Frank Chang, frank.chang@sifive.com
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms and conditions of the GNU General Public License,
9  * version 2 or later, as published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
14  * more details.
15  *
16  * You should have received a copy of the GNU General Public License along with
17  * this program.  If not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include "qemu/osdep.h"
21 #include "qemu/host-utils.h"
22 #include "exec/exec-all.h"
23 #include "exec/helper-proto.h"
24 #include "tcg/tcg.h"
25 
26 static const uint64_t adjacent_masks[] = {
27     dup_const(MO_8, 0x55),
28     dup_const(MO_8, 0x33),
29     dup_const(MO_8, 0x0f),
30     dup_const(MO_16, 0xff),
31     dup_const(MO_32, 0xffff),
32     UINT32_MAX
33 };
34 
35 static inline target_ulong do_swap(target_ulong x, uint64_t mask, int shift)
36 {
37     return ((x & mask) << shift) | ((x & ~mask) >> shift);
38 }
39 
40 static target_ulong do_grev(target_ulong rs1,
41                             target_ulong rs2,
42                             int bits)
43 {
44     target_ulong x = rs1;
45     int i, shift;
46 
47     for (i = 0, shift = 1; shift < bits; i++, shift <<= 1) {
48         if (rs2 & shift) {
49             x = do_swap(x, adjacent_masks[i], shift);
50         }
51     }
52 
53     return x;
54 }
55 
56 target_ulong HELPER(grev)(target_ulong rs1, target_ulong rs2)
57 {
58     return do_grev(rs1, rs2, TARGET_LONG_BITS);
59 }
60 
61 target_ulong HELPER(grevw)(target_ulong rs1, target_ulong rs2)
62 {
63     return do_grev(rs1, rs2, 32);
64 }
65 
66 static target_ulong do_gorc(target_ulong rs1,
67                             target_ulong rs2,
68                             int bits)
69 {
70     target_ulong x = rs1;
71     int i, shift;
72 
73     for (i = 0, shift = 1; shift < bits; i++, shift <<= 1) {
74         if (rs2 & shift) {
75             x |= do_swap(x, adjacent_masks[i], shift);
76         }
77     }
78 
79     return x;
80 }
81 
82 target_ulong HELPER(gorc)(target_ulong rs1, target_ulong rs2)
83 {
84     return do_gorc(rs1, rs2, TARGET_LONG_BITS);
85 }
86 
87 target_ulong HELPER(gorcw)(target_ulong rs1, target_ulong rs2)
88 {
89     return do_gorc(rs1, rs2, 32);
90 }
91