LXR qemu/target/riscv/bitmanip

   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
  27target_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
  40target_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
  53static inline target_ulong do_swap(target_ulong x, uint64_t mask, int shift)
  54{
  55    return ((x & mask) << shift) | ((x & ~mask) >> shift);
  56}
  57
  58target_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
  68static 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
  75static 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
  84target_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
  95target_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
 106static 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
 123target_ulong HELPER(xperm4)(target_ulong rs1, target_ulong rs2)
 124{
 125    return do_xperm(rs1, rs2, 2);
 126}
 127
 128target_ulong HELPER(xperm8)(target_ulong rs1, target_ulong rs2)
 129{
 130    return do_xperm(rs1, rs2, 3);
 131}
 132