Lionel Sambuc 0a6a1f1d05 NetBSD re-synchronization of the source tree
This brings our tree to NetBSD 7.0, as found on -current on the
10-10-2015.

This updates:
 - LLVM to 3.6.1
 - GCC to GCC 5.1
 - Replace minix/commands/zdump with usr.bin/zdump
 - external/bsd/libelf has moved to /external/bsd/elftoolchain/
 - Import ctwm
 - Drop sprintf from libminc

Change-Id: I149836ac18e9326be9353958bab9b266efb056f0
2016-01-13 20:32:14 +01:00

61 lines
1.4 KiB
C

/* ===-- mulvti3.c - Implement __mulvti3 -----------------------------------===
*
* The LLVM Compiler Infrastructure
*
* This file is dual licensed under the MIT and the University of Illinois Open
* Source Licenses. See LICENSE.TXT for details.
*
* ===----------------------------------------------------------------------===
*
* This file implements __mulvti3 for the compiler_rt library.
*
* ===----------------------------------------------------------------------===
*/
#include "int_lib.h"
#ifdef CRT_HAS_128BIT
/* Returns: a * b */
/* Effects: aborts if a * b overflows */
COMPILER_RT_ABI ti_int
__mulvti3(ti_int a, ti_int b)
{
const int N = (int)(sizeof(ti_int) * CHAR_BIT);
const ti_int MIN = (ti_int)1 << (N-1);
const ti_int MAX = ~MIN;
if (a == MIN)
{
if (b == 0 || b == 1)
return a * b;
compilerrt_abort();
}
if (b == MIN)
{
if (a == 0 || a == 1)
return a * b;
compilerrt_abort();
}
ti_int sa = a >> (N - 1);
ti_int abs_a = (a ^ sa) - sa;
ti_int sb = b >> (N - 1);
ti_int abs_b = (b ^ sb) - sb;
if (abs_a < 2 || abs_b < 2)
return a * b;
if (sa == sb)
{
if (abs_a > MAX / abs_b)
compilerrt_abort();
}
else
{
if (abs_a > MIN / -abs_b)
compilerrt_abort();
}
return a * b;
}
#endif /* CRT_HAS_128BIT */