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This change ports APE Loader to Linux AARCH64, so that Raspberry Pi users can run programs like redbean, without the executable needing to modify itself. Progress has also slipped into this change on the issue of making progress better conforming to user expectations and industry standards regarding which symbols we're allowed to declare
71 lines
1.9 KiB
C
71 lines
1.9 KiB
C
/* clang-format off */
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/* ===-- udivsi3.c - Implement __udivsi3 -----------------------------------===
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*
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* The LLVM Compiler Infrastructure
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*
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* This file is dual licensed under the MIT and the University of Illinois Open
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* Source Licenses. See LICENSE.TXT for details.
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*
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* ===----------------------------------------------------------------------===
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*
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* This file implements __udivsi3 for the compiler_rt library.
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*
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* ===----------------------------------------------------------------------===
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*/
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__static_yoink("huge_compiler_rt_license");
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#include "third_party/compiler_rt/int_lib.h"
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/* Returns: a / b */
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/* Translated from Figure 3-40 of The PowerPC Compiler Writer's Guide */
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/* This function should not call __divsi3! */
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COMPILER_RT_ABI su_int
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__udivsi3(su_int n, su_int d)
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{
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const unsigned n_uword_bits = sizeof(su_int) * CHAR_BIT;
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su_int q;
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su_int r;
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unsigned sr;
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/* special cases */
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if (d == 0)
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return 0; /* ?! */
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if (n == 0)
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return 0;
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sr = __builtin_clz(d) - __builtin_clz(n);
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/* 0 <= sr <= n_uword_bits - 1 or sr large */
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if (sr > n_uword_bits - 1) /* d > r */
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return 0;
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if (sr == n_uword_bits - 1) /* d == 1 */
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return n;
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++sr;
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/* 1 <= sr <= n_uword_bits - 1 */
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/* Not a special case */
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q = n << (n_uword_bits - sr);
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r = n >> sr;
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su_int carry = 0;
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for (; sr > 0; --sr)
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{
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/* r:q = ((r:q) << 1) | carry */
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r = (r << 1) | (q >> (n_uword_bits - 1));
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q = (q << 1) | carry;
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/* carry = 0;
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* if (r.all >= d.all)
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* {
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* r.all -= d.all;
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* carry = 1;
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* }
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*/
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const si_int s = (si_int)(d - r - 1) >> (n_uword_bits - 1);
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carry = s & 1;
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r -= d & s;
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}
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q = (q << 1) | carry;
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return q;
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}
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#if defined(__ARM_EABI__)
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AEABI_RTABI su_int __aeabi_uidiv(su_int n, su_int d) COMPILER_RT_ALIAS(__udivsi3);
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#endif
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