diff options
Diffstat (limited to 'compiler-rt/lib/builtins/lshrti3.c')
-rw-r--r-- | compiler-rt/lib/builtins/lshrti3.c | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/compiler-rt/lib/builtins/lshrti3.c b/compiler-rt/lib/builtins/lshrti3.c new file mode 100644 index 000000000000..d00a22095993 --- /dev/null +++ b/compiler-rt/lib/builtins/lshrti3.c @@ -0,0 +1,38 @@ +//===-- lshrti3.c - Implement __lshrti3 -----------------------------------===// +// +// 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 __lshrti3 for the compiler_rt library. +// +//===----------------------------------------------------------------------===// + +#include "int_lib.h" + +#ifdef CRT_HAS_128BIT + +// Returns: logical a >> b + +// Precondition: 0 <= b < bits_in_tword + +COMPILER_RT_ABI ti_int __lshrti3(ti_int a, si_int b) { + const int bits_in_dword = (int)(sizeof(di_int) * CHAR_BIT); + utwords input; + utwords result; + input.all = a; + if (b & bits_in_dword) /* bits_in_dword <= b < bits_in_tword */ { + result.s.high = 0; + 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 = (input.s.high << (bits_in_dword - b)) | (input.s.low >> b); + } + return result.all; +} + +#endif // CRT_HAS_128BIT |