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Diffstat (limited to 'contrib/compiler-rt/lib/ashlti3.c')
-rw-r--r-- | contrib/compiler-rt/lib/ashlti3.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/contrib/compiler-rt/lib/ashlti3.c b/contrib/compiler-rt/lib/ashlti3.c new file mode 100644 index 0000000..317de66 --- /dev/null +++ b/contrib/compiler-rt/lib/ashlti3.c @@ -0,0 +1,45 @@ +/* ===-- ashlti3.c - Implement __ashlti3 -----------------------------------=== + * + * The LLVM Compiler Infrastructure + * + * This file is distributed under the University of Illinois Open Source + * License. See LICENSE.TXT for details. + * + * ===----------------------------------------------------------------------=== + * + * This file implements __ashlti3 for the compiler_rt library. + * + * ===----------------------------------------------------------------------=== + */ + +#if __x86_64 + +#include "int_lib.h" + +/* Returns: a << b */ + +/* Precondition: 0 <= b < bits_in_tword */ + +ti_int +__ashlti3(ti_int a, si_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.low = 0; + result.s.high = input.s.low << (b - bits_in_dword); + } + else /* 0 <= b < bits_in_dword */ + { + if (b == 0) + return a; + result.s.low = input.s.low << b; + result.s.high = (input.s.high << b) | (input.s.low >> (bits_in_dword - b)); + } + return result.all; +} + +#endif /* __x86_64 */ |