target/riscv/bitmanip_helper.c

   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  * Copyright (c) 2021 Philipp Tomsich, philipp.tomsich@vrull.eu
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms and conditions of the GNU General Public License,
  10  * version 2 or later, as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope it will be useful, but WITHOUT
  13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  15  * more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along with
  18  * this program.  If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include "qemu/osdep.h"
  22 #include "qemu/host-utils.h"
  23 #include "exec/exec-all.h"
  24 #include "exec/helper-proto.h"
  25 #include "tcg/tcg.h"
  26
  27 target_ulong HELPER(clmul)(target_ulong rs1, target_ulong rs2)
  28 {
  29     target_ulong result = 0;
  30
  31     for (int i = 0; i < TARGET_LONG_BITS; i++) {
  32         if ((rs2 >> i) & 1) {
  33             result ^= (rs1 << i);
  34         }
  35     }
  36
  37     return result;
  38 }
  39
  40 target_ulong HELPER(clmulr)(target_ulong rs1, target_ulong rs2)
  41 {
  42     target_ulong result = 0;
  43
  44     for (int i = 0; i < TARGET_LONG_BITS; i++) {
  45         if ((rs2 >> i) & 1) {
  46             result ^= (rs1 >> (TARGET_LONG_BITS - i - 1));
  47         }
  48     }
  49
  50     return result;
  51 }
  52
  53 static inline target_ulong do_swap(target_ulong x, uint64_t mask, int shift)
  54 {
  55     return ((x & mask) << shift) | ((x & ~mask) >> shift);
  56 }
  57
  58 target_ulong HELPER(brev8)(target_ulong rs1)
  59 {
  60     target_ulong x = rs1;
  61
  62     x = do_swap(x, 0x5555555555555555ull, 1);
  63     x = do_swap(x, 0x3333333333333333ull, 2);
  64     x = do_swap(x, 0x0f0f0f0f0f0f0f0full, 4);
  65     return x;
  66 }
  67
  68 static const uint64_t shuf_masks[] = {
  69     dup_const(MO_8, 0x44),
  70     dup_const(MO_8, 0x30),
  71     dup_const(MO_16, 0x0f00),
  72     dup_const(MO_32, 0xff0000)
  73 };
  74
  75 static inline target_ulong do_shuf_stage(target_ulong src, uint64_t maskL,
  76                                          uint64_t maskR, int shift)
  77 {
  78     target_ulong x = src & ~(maskL | maskR);
  79
  80     x |= ((src << shift) & maskL) | ((src >> shift) & maskR);
  81     return x;
  82 }
  83
  84 target_ulong HELPER(unzip)(target_ulong rs1)
  85 {
  86     target_ulong x = rs1;
  87
  88     x = do_shuf_stage(x, shuf_masks[0], shuf_masks[0] >> 1, 1);
  89     x = do_shuf_stage(x, shuf_masks[1], shuf_masks[1] >> 2, 2);
  90     x = do_shuf_stage(x, shuf_masks[2], shuf_masks[2] >> 4, 4);
  91     x = do_shuf_stage(x, shuf_masks[3], shuf_masks[3] >> 8, 8);
  92     return x;
  93 }
  94
  95 target_ulong HELPER(zip)(target_ulong rs1)
  96 {
  97     target_ulong x = rs1;
  98
  99     x = do_shuf_stage(x, shuf_masks[3], shuf_masks[3] >> 8, 8);
 100     x = do_shuf_stage(x, shuf_masks[2], shuf_masks[2] >> 4, 4);
 101     x = do_shuf_stage(x, shuf_masks[1], shuf_masks[1] >> 2, 2);
 102     x = do_shuf_stage(x, shuf_masks[0], shuf_masks[0] >> 1, 1);
 103     return x;
 104 }
 105
 106 static inline target_ulong do_xperm(target_ulong rs1, target_ulong rs2,
 107                                     uint32_t sz_log2)
 108 {
 109     target_ulong r = 0;
 110     target_ulong sz = 1LL << sz_log2;
 111     target_ulong mask = (1LL << sz) - 1;
 112     target_ulong pos;
 113
 114     for (int i = 0; i < TARGET_LONG_BITS; i += sz) {
 115         pos = ((rs2 >> i) & mask) << sz_log2;
 116         if (pos < sizeof(target_ulong) * 8) {
 117             r |= ((rs1 >> pos) & mask) << i;
 118         }
 119     }
 120     return r;
 121 }
 122
 123 target_ulong HELPER(xperm4)(target_ulong rs1, target_ulong rs2)
 124 {
 125     return do_xperm(rs1, rs2, 2);
 126 }
 127
 128 target_ulong HELPER(xperm8)(target_ulong rs1, target_ulong rs2)
 129 {
 130     return do_xperm(rs1, rs2, 3);
 131 }