diff options
Diffstat (limited to 'contrib/llvm-project/compiler-rt/lib/builtins/ashrti3.c')
| -rw-r--r-- | contrib/llvm-project/compiler-rt/lib/builtins/ashrti3.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/contrib/llvm-project/compiler-rt/lib/builtins/ashrti3.c b/contrib/llvm-project/compiler-rt/lib/builtins/ashrti3.c new file mode 100644 index 000000000000..d6b1ad9192bf --- /dev/null +++ b/contrib/llvm-project/compiler-rt/lib/builtins/ashrti3.c @@ -0,0 +1,40 @@ +//===-- ashrti3.c - Implement __ashrti3 -----------------------------------===// +// +// 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 __ashrti3 for the compiler_rt library. +// +//===----------------------------------------------------------------------===// + +#include "int_lib.h" + +#ifdef CRT_HAS_128BIT + +// Returns: arithmetic a >> b + +// Precondition: 0 <= b < bits_in_tword + +COMPILER_RT_ABI ti_int __ashrti3(ti_int a, int b) { + const int bits_in_dword = (int)(sizeof(di_int) * CHAR_BIT); + twords input; + twords result; + input.all = a; + if (b & bits_in_dword) /* bits_in_dword <= b < bits_in_tword */ { + // result.s.high = input.s.high < 0 ? -1 : 0 + result.s.high = input.s.high >> (bits_in_dword - 1); + result.s.low = input.s.high >> (b - bits_in_dword); + } else /* 0 <= b < bits_in_dword */ { + if (b == 0) + return a; + result.s.high = input.s.high >> b; + result.s.low = + ((du_int)input.s.high << (bits_in_dword - b)) | (input.s.low >> b); + } + return result.all; +} + +#endif // CRT_HAS_128BIT |
