mirror of https://github.com/acidanthera/audk.git
288 lines
9.6 KiB
C
288 lines
9.6 KiB
C
/** @file
|
|
Compiler intrinsic for 64-bit compare, ported from LLVM code.
|
|
|
|
Copyright (c) 2008-2009, Apple Inc. All rights reserved.<BR>
|
|
|
|
This program and the accompanying materials
|
|
are licensed and made available under the terms and conditions of the BSD License
|
|
which accompanies this distribution. The full text of the license may be found at
|
|
http://opensource.org/licenses/bsd-license.php
|
|
|
|
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
|
|
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
|
|
|
|
**/
|
|
/**
|
|
University of Illinois/NCSA
|
|
Open Source License
|
|
|
|
Copyright (c) 2003-2008 University of Illinois at Urbana-Champaign.
|
|
All rights reserved.
|
|
|
|
Developed by:
|
|
|
|
LLVM Team
|
|
|
|
University of Illinois at Urbana-Champaign
|
|
|
|
http://llvm.org
|
|
|
|
Permission is hereby granted, free of charge, to any person obtaining a copy of
|
|
this software and associated documentation files (the "Software"), to deal with
|
|
the Software without restriction, including without limitation the rights to
|
|
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
|
|
of the Software, and to permit persons to whom the Software is furnished to do
|
|
so, subject to the following conditions:
|
|
|
|
* Redistributions of source code must retain the above copyright notice,
|
|
this list of conditions and the following disclaimers.
|
|
|
|
* Redistributions in binary form must reproduce the above copyright notice,
|
|
this list of conditions and the following disclaimers in the
|
|
documentation and/or other materials provided with the distribution.
|
|
|
|
* Neither the names of the LLVM Team, University of Illinois at
|
|
Urbana-Champaign, nor the names of its contributors may be used to
|
|
endorse or promote products derived from this Software without specific
|
|
prior written permission.
|
|
|
|
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
|
|
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS WITH THE
|
|
SOFTWARE.
|
|
**/
|
|
|
|
|
|
#include "Llvm_int_lib.h"
|
|
|
|
// Effects: if rem != 0, *rem = a % b
|
|
// Returns: a / b
|
|
|
|
// Translated from Figure 3-40 of The PowerPC Compiler Writer's Guide
|
|
|
|
UINT64
|
|
__udivmoddi4 (UINT64 a, UINT64 b, UINT64* rem)
|
|
{
|
|
const unsigned n_uword_bits = sizeof(UINT32) * CHAR_BIT;
|
|
const unsigned n_udword_bits = sizeof(UINT64) * CHAR_BIT;
|
|
udwords n;
|
|
n.all = a;
|
|
udwords d;
|
|
d.all = b;
|
|
udwords q;
|
|
udwords r;
|
|
unsigned sr;
|
|
|
|
if (b == 0) {
|
|
// ASSERT (FALSE);
|
|
return 0;
|
|
}
|
|
|
|
// special cases, X is unknown, K != 0
|
|
if (n.high == 0)
|
|
{
|
|
if (d.high == 0)
|
|
{
|
|
// 0 X
|
|
// ---
|
|
// 0 X
|
|
if (rem)
|
|
*rem = n.low % d.low;
|
|
return n.low / d.low;
|
|
}
|
|
// 0 X
|
|
// ---
|
|
// K X
|
|
if (rem)
|
|
*rem = n.low;
|
|
return 0;
|
|
}
|
|
// n.high != 0
|
|
if (d.low == 0)
|
|
{
|
|
if (d.high == 0)
|
|
{
|
|
// K X
|
|
// ---
|
|
// 0 0
|
|
if (rem)
|
|
*rem = n.high % d.low;
|
|
return n.high / d.low;
|
|
}
|
|
// d.high != 0
|
|
if (n.low == 0)
|
|
{
|
|
// K 0
|
|
// ---
|
|
// K 0
|
|
if (rem)
|
|
{
|
|
r.high = n.high % d.high;
|
|
r.low = 0;
|
|
*rem = r.all;
|
|
}
|
|
return n.high / d.high;
|
|
}
|
|
// K K
|
|
// ---
|
|
// K 0
|
|
if ((d.high & (d.high - 1)) == 0) // if d is a power of 2
|
|
{
|
|
if (rem)
|
|
{
|
|
r.low = n.low;
|
|
r.high = n.high & (d.high - 1);
|
|
*rem = r.all;
|
|
}
|
|
return n.high >> COUNT_TRAILING_ZEROS(d.high);
|
|
}
|
|
// K K
|
|
// ---
|
|
// K 0
|
|
sr = COUNT_LEADING_ZEROS(d.high) - COUNT_LEADING_ZEROS(n.high);
|
|
// 0 <= sr <= n_uword_bits - 2 or sr large
|
|
if (sr > n_uword_bits - 2)
|
|
{
|
|
if (rem)
|
|
*rem = n.all;
|
|
return 0;
|
|
}
|
|
++sr;
|
|
// 1 <= sr <= n_uword_bits - 1
|
|
// q.all = n.all << (n_udword_bits - sr);
|
|
q.low = 0;
|
|
q.high = n.low << (n_uword_bits - sr);
|
|
// r.all = n.all >> sr;
|
|
r.high = n.high >> sr;
|
|
r.low = (n.high << (n_uword_bits - sr)) | (n.low >> sr);
|
|
}
|
|
else // d.low != 0
|
|
{
|
|
if (d.high == 0)
|
|
{
|
|
// K X
|
|
// ---
|
|
// 0 K
|
|
if ((d.low & (d.low - 1)) == 0) // if d is a power of 2
|
|
{
|
|
if (rem)
|
|
*rem = n.low & (d.low - 1);
|
|
if (d.low == 1)
|
|
return n.all;
|
|
unsigned sr = COUNT_TRAILING_ZEROS(d.low);
|
|
q.high = n.high >> sr;
|
|
q.low = (n.high << (n_uword_bits - sr)) | (n.low >> sr);
|
|
return q.all;
|
|
}
|
|
// K X
|
|
// ---
|
|
// 0 K
|
|
sr = 1 + n_uword_bits + COUNT_LEADING_ZEROS(d.low) - COUNT_LEADING_ZEROS(n.high);
|
|
// 2 <= sr <= n_udword_bits - 1
|
|
// q.all = n.all << (n_udword_bits - sr);
|
|
// r.all = n.all >> sr;
|
|
// if (sr == n_uword_bits)
|
|
// {
|
|
// q.low = 0;
|
|
// q.high = n.low;
|
|
// r.high = 0;
|
|
// r.low = n.high;
|
|
// }
|
|
// else if (sr < n_uword_bits) // 2 <= sr <= n_uword_bits - 1
|
|
// {
|
|
// q.low = 0;
|
|
// q.high = n.low << (n_uword_bits - sr);
|
|
// r.high = n.high >> sr;
|
|
// r.low = (n.high << (n_uword_bits - sr)) | (n.low >> sr);
|
|
// }
|
|
// else // n_uword_bits + 1 <= sr <= n_udword_bits - 1
|
|
// {
|
|
// q.low = n.low << (n_udword_bits - sr);
|
|
// q.high = (n.high << (n_udword_bits - sr)) |
|
|
// (n.low >> (sr - n_uword_bits));
|
|
// r.high = 0;
|
|
// r.low = n.high >> (sr - n_uword_bits);
|
|
// }
|
|
q.low = (n.low << (n_udword_bits - sr)) &
|
|
((INT32)(n_uword_bits - sr) >> (n_uword_bits-1));
|
|
q.high = ((n.low << ( n_uword_bits - sr)) &
|
|
((INT32)(sr - n_uword_bits - 1) >> (n_uword_bits-1))) |
|
|
(((n.high << (n_udword_bits - sr)) |
|
|
(n.low >> (sr - n_uword_bits))) &
|
|
((INT32)(n_uword_bits - sr) >> (n_uword_bits-1)));
|
|
r.high = (n.high >> sr) &
|
|
((INT32)(sr - n_uword_bits) >> (n_uword_bits-1));
|
|
r.low = ((n.high >> (sr - n_uword_bits)) &
|
|
((INT32)(n_uword_bits - sr - 1) >> (n_uword_bits-1))) |
|
|
(((n.high << (n_uword_bits - sr)) |
|
|
(n.low >> sr)) &
|
|
((INT32)(sr - n_uword_bits) >> (n_uword_bits-1)));
|
|
}
|
|
else
|
|
{
|
|
// K X
|
|
// ---
|
|
// K K
|
|
sr = COUNT_LEADING_ZEROS(d.high) - COUNT_LEADING_ZEROS(n.high);
|
|
// 0 <= sr <= n_uword_bits - 1 or sr large
|
|
if (sr > n_uword_bits - 1)
|
|
{
|
|
if (rem)
|
|
*rem = n.all;
|
|
return 0;
|
|
}
|
|
++sr;
|
|
// 1 <= sr <= n_uword_bits
|
|
// q.all = n.all << (n_udword_bits - sr);
|
|
q.low = 0;
|
|
q.high = n.low << (n_uword_bits - sr);
|
|
// r.all = n.all >> sr;
|
|
// if (sr < n_uword_bits)
|
|
// {
|
|
// r.high = n.high >> sr;
|
|
// r.low = (n.high << (n_uword_bits - sr)) | (n.low >> sr);
|
|
// }
|
|
// else
|
|
// {
|
|
// r.high = 0;
|
|
// r.low = n.high;
|
|
// }
|
|
r.high = (n.high >> sr) &
|
|
((INT32)(sr - n_uword_bits) >> (n_uword_bits-1));
|
|
r.low = (n.high << (n_uword_bits - sr)) |
|
|
((n.low >> sr) &
|
|
((INT32)(sr - n_uword_bits) >> (n_uword_bits-1)));
|
|
}
|
|
}
|
|
// Not a special case
|
|
// q and r are initialized with:
|
|
// q.all = n.all << (n_udword_bits - sr);
|
|
// r.all = n.all >> sr;
|
|
// 1 <= sr <= n_udword_bits - 1
|
|
UINT32 carry = 0;
|
|
for (; sr > 0; --sr)
|
|
{
|
|
// r:q = ((r:q) << 1) | carry
|
|
r.high = (r.high << 1) | (r.low >> (n_uword_bits - 1));
|
|
r.low = (r.low << 1) | (q.high >> (n_uword_bits - 1));
|
|
q.high = (q.high << 1) | (q.low >> (n_uword_bits - 1));
|
|
q.low = (q.low << 1) | carry;
|
|
// carry = 0;
|
|
// if (r.all >= d.all)
|
|
// {
|
|
// r.all -= d.all;
|
|
// carry = 1;
|
|
// }
|
|
const INT64 s = (INT64)(d.all - r.all - 1) >> (n_udword_bits - 1);
|
|
carry = s & 1;
|
|
r.all -= d.all & s;
|
|
}
|
|
q.all = (q.all << 1) | carry;
|
|
if (rem)
|
|
*rem = r.all;
|
|
return q.all;
|
|
}
|