Markus F.X.J. Oberhumer
153 lines
4.6 KiB
C++
153 lines
4.6 KiB
C++
/* ppcbxx.h -- PowerPC Branch trick
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This file is part of the UPX executable compressor.
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Copyright (C) 1996-2025 Markus Franz Xaver Johannes Oberhumer
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Copyright (C) 1996-2025 Laszlo Molnar
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Copyright (C) 2004-2025 John F. Reiser
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All Rights Reserved.
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UPX and the UCL library are free software; you can redistribute them
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and/or modify them under the terms of the GNU General Public License as
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published by the Free Software Foundation; either version 2 of
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the License, or (at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; see the file COPYING.
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If not, write to the Free Software Foundation, Inc.,
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59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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Markus F.X.J. Oberhumer Laszlo Molnar
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<markus@oberhumer.com> <ezerotven+github@gmail.com>
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John F. Reiser
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<jreiser@users.sourceforge.net>
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*/
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/*************************************************************************
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// filter / scan
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**************************************************************************/
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#define W_CTO 4 /* width of cto; must match stub/ppc_bxx.S */
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static int F(Filter *f) {
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#ifdef U
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// filter
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byte *b = f->buf;
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const unsigned addvalue = f->addvalue;
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#else
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// scan
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const byte *b = f->buf;
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#endif
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const unsigned size = upx::umin(f->buf_len, 0u - (~0u << (32 - (6 + W_CTO))));
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const unsigned size4 = size - 4;
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unsigned ic;
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unsigned calls = 0, noncalls = 0;
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unsigned lastnoncall = size, lastcall = 0;
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// find 26-2-W_CTO bits of displacements that contain no targets
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{
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unsigned char buf[256];
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unsigned short wbuf[256];
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const size_t WW = (size_t) 0 - ((~(size_t) 0) << W_CTO); // ???
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memset(wbuf, 0, sizeof(wbuf));
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memset(buf, 0, WW);
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memset(buf + WW, 1, 256 - WW);
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for (ic = 0; ic <= size4; ic += 4)
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if (COND(b, ic)) {
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unsigned const off = (int) (get_be32(b + ic) << 6) >> 6;
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if (size <= (off & (~0u << 2)) + ic) {
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buf[(~(~0u << W_CTO)) & (off >> (26 - W_CTO))] |= 1;
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++wbuf[0xff & (off >> 18)];
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}
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}
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if (getcto(f, buf) < 0) {
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#if (W_CTO != 0)
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return -1;
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#else
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f->cto = 0;
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#endif
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}
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}
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const unsigned char cto8 = f->cto;
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#ifdef U
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const unsigned cto = (unsigned) f->cto << (24 + 2 - W_CTO);
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#endif
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for (ic = 0; ic <= size4; ic += 4)
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if (COND(b, ic)) {
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unsigned const word = get_be32(b + ic);
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unsigned const off = (int) (word << 6) >> 6;
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unsigned const jc = (off & (~0u << 2)) + ic;
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// try to detect 'real' calls only
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if (jc < size) {
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#ifdef U
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set_be32(b + ic, (0xfc000003 & word) | (jc + addvalue + cto));
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#endif
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calls++;
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lastcall = ic;
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} else {
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#if (W_CTO != 0)
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assert((~(~0u << W_CTO) & (word >> (24 + 2 - W_CTO))) !=
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(unsigned) cto8); // this should not happen
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#endif
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lastnoncall = ic;
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noncalls++;
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}
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}
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f->calls = calls;
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f->noncalls = noncalls;
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f->lastcall = lastcall;
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ACC_UNUSED(lastnoncall);
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#if 0 || defined(TESTING)
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printf("\ncalls=%d noncalls=%d text_size=%x calltrickoffset=%x\n",
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calls,noncalls,size,cto8);
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#endif
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return 0;
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}
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/*************************************************************************
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// unfilter
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**************************************************************************/
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#ifdef U
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static int U(Filter *f) {
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byte *b = f->buf;
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const unsigned size4 = upx::umin(f->buf_len - 4, 0u - (~0u << (32 - (6 + W_CTO))));
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const unsigned addvalue = f->addvalue;
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unsigned ic;
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for (ic = 0; ic <= size4; ic += 4)
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if (COND(b, ic)) {
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unsigned const word = get_be32(b + ic);
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if ((~(~0u << W_CTO) & (word >> (24 + 2 - W_CTO))) == (unsigned) f->cto) {
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unsigned const jc = word & (~(~0u << (26 - W_CTO)) & (~0u << 2));
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set_be32(b + ic, (0xfc000003 & word) | (0x03fffffc & (jc - ic - addvalue)));
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f->calls++;
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f->lastcall = ic;
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} else {
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f->noncalls++;
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}
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}
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return 0;
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}
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#endif
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#undef F
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#undef U
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#undef W_CTO
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/* vim:set ts=4 sw=4 et: */
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