ef8821e5db
It seems there have only been a small amount to the compiler-rt source code in the mean time. I'd rather have the code in sync as much as possible by the time we release 9.0. Changes: - The libcompiler_rt library is now dual licensed under both the University of Illinois "BSD-Like" license and the MIT license. - Our local modifications for using .hidden instead of .private_extern have been upstreamed, meaning our changes to lib/assembly.h can now be reverted. - A possible endless recursion in __modsi3() has been fixed. - Support for ARM EABI has been added, but it has no effect on FreeBSD (yet). - The functions __udivmodsi4 and __divmodsi4 have been added. Requested by: many, including bf@ and Pedro Giffuni
58 lines
1.4 KiB
C
58 lines
1.4 KiB
C
/* ===-- mulvsi3.c - Implement __mulvsi3 -----------------------------------===
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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 __mulvsi3 for the compiler_rt library.
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*
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* ===----------------------------------------------------------------------===
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*/
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#include "int_lib.h"
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#include <stdlib.h>
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/* Returns: a * b */
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/* Effects: aborts if a * b overflows */
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si_int
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__mulvsi3(si_int a, si_int b)
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{
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const int N = (int)(sizeof(si_int) * CHAR_BIT);
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const si_int MIN = (si_int)1 << (N-1);
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const si_int MAX = ~MIN;
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if (a == MIN)
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{
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if (b == 0 || b == 1)
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return a * b;
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compilerrt_abort();
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}
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if (b == MIN)
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{
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if (a == 0 || a == 1)
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return a * b;
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compilerrt_abort();
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}
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si_int sa = a >> (N - 1);
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si_int abs_a = (a ^ sa) - sa;
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si_int sb = b >> (N - 1);
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si_int abs_b = (b ^ sb) - sb;
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if (abs_a < 2 || abs_b < 2)
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return a * b;
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if (sa == sb)
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{
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if (abs_a > MAX / abs_b)
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compilerrt_abort();
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}
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else
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{
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if (abs_a > MIN / -abs_b)
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compilerrt_abort();
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}
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return a * b;
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}
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