81 lines
3.6 KiB
C
81 lines
3.6 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2020 Justine Alexandra Roberts Tunney │
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│ │
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│ This program is free software; you can redistribute it and/or modify │
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│ it under the terms of the GNU General Public License as published by │
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│ the Free Software Foundation; version 2 of the License. │
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│ │
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│ This program is distributed in the hope that it will be useful, but │
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│ WITHOUT ANY WARRANTY; without even the implied warranty of │
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│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
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│ General Public License for more details. │
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│ │
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│ You should have received a copy of the GNU General Public License │
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│ along with this program; if not, write to the Free Software │
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│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
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│ 02110-1301 USA │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "tool/build/lib/bitscan.h"
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#include "tool/build/lib/flags.h"
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#include "tool/build/lib/machine.h"
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#include "tool/build/lib/modrm.h"
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uint64_t AluBsr(struct Machine *m, uint32_t rde, uint64_t x) {
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unsigned i;
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if (Rexw(rde)) {
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x &= 0xffffffffffffffff;
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m->flags = SetFlag(m->flags, FLAGS_ZF, !x);
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if (!x) return 0;
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return 63 ^ __builtin_clzll(x);
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} else if (!Osz(rde)) {
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x &= 0xffffffff;
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m->flags = SetFlag(m->flags, FLAGS_ZF, !x);
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if (!x) return 0;
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return 31 ^ __builtin_clz(x);
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} else {
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x &= 0xffff;
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m->flags = SetFlag(m->flags, FLAGS_ZF, !x);
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if (!x) return 0;
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for (i = 15; !(x & 0x8000); --i) x <<= 1;
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return i;
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}
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}
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uint64_t AluBsf(struct Machine *m, uint32_t rde, uint64_t x) {
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unsigned i;
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if (Rexw(rde)) {
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x &= 0xffffffffffffffff;
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m->flags = SetFlag(m->flags, FLAGS_ZF, !x);
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if (!x) return 0;
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return __builtin_ctzll(x);
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} else if (!Osz(rde)) {
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x &= 0xffffffff;
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m->flags = SetFlag(m->flags, FLAGS_ZF, !x);
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if (!x) return 0;
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return __builtin_ctz(x);
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} else {
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x &= 0xffff;
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m->flags = SetFlag(m->flags, FLAGS_ZF, !x);
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if (!x) return 0;
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for (i = 0; !(x & 1); ++i) x >>= 1;
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return i;
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}
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}
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uint64_t AluPopcnt(struct Machine *m, uint32_t rde, uint64_t x) {
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m->flags = SetFlag(m->flags, FLAGS_ZF, !x);
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m->flags = SetFlag(m->flags, FLAGS_CF, false);
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m->flags = SetFlag(m->flags, FLAGS_SF, false);
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m->flags = SetFlag(m->flags, FLAGS_OF, false);
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m->flags = SetFlag(m->flags, FLAGS_PF, false);
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x = x - ((x >> 1) & 0x5555555555555555);
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x = ((x >> 2) & 0x3333333333333333) + (x & 0x3333333333333333);
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x = (x + (x >> 4)) & 0x0f0f0f0f0f0f0f0f;
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x = (x + (x >> 32)) & 0xffffffff;
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x = x + (x >> 16);
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x = (x + (x >> 8)) & 0x7f;
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return x;
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}
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