01220bf9d2
Summary: During MIPS implementation work for FreeBSD, John Baldwin (jhb@FreeBSD.org) found that gcc 6.x emits calls to __ffssi2() when compiling libc and some userland programs in the base system. Add it to compiler-rt's builtins, based off of the existing __ffsdi2() implementation. Also update the CMake files and add a test case. Reviewers: howard.hinnant, weimingz, rengolin, compnerd Reviewed By: weimingz Subscribers: dberris, mgorny, llvm-commits, emaste Differential Revision: https://reviews.llvm.org/D31721 llvm-svn: 299675
30 lines
793 B
C
30 lines
793 B
C
/* ===-- ffssi2.c - Implement __ffssi2 -------------------------------------===
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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 __ffssi2 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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/* Returns: the index of the least significant 1-bit in a, or
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* the value zero if a is zero. The least significant bit is index one.
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*/
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COMPILER_RT_ABI si_int
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__ffssi2(si_int a)
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{
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if (a == 0)
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{
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return 0;
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}
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return __builtin_ctz(a) + 1;
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}
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