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Diffstat (limited to 'lib/compiler-rt/builtins/lshrdi3.c')
-rw-r--r-- | lib/compiler-rt/builtins/lshrdi3.c | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/lib/compiler-rt/builtins/lshrdi3.c b/lib/compiler-rt/builtins/lshrdi3.c new file mode 100644 index 0000000..6072152 --- /dev/null +++ b/lib/compiler-rt/builtins/lshrdi3.c @@ -0,0 +1,38 @@ +//===-- lshrdi3.c - Implement __lshrdi3 -----------------------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// +// This file implements __lshrdi3 for the compiler_rt library. +// +//===----------------------------------------------------------------------===// + +#include "int_lib.h" + +// Returns: logical a >> b + +// Precondition: 0 <= b < bits_in_dword + +COMPILER_RT_ABI di_int __lshrdi3(di_int a, int b) { + const int bits_in_word = (int)(sizeof(si_int) * CHAR_BIT); + udwords input; + udwords result; + input.all = a; + if (b & bits_in_word) /* bits_in_word <= b < bits_in_dword */ { + result.s.high = 0; + result.s.low = input.s.high >> (b - bits_in_word); + } else /* 0 <= b < bits_in_word */ { + if (b == 0) + return a; + result.s.high = input.s.high >> b; + result.s.low = (input.s.high << (bits_in_word - b)) | (input.s.low >> b); + } + return result.all; +} + +#if defined(__ARM_EABI__) +COMPILER_RT_ALIAS(__lshrdi3, __aeabi_llsr) +#endif |