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author | Alexey Samsonov <samsonov@google.com> | 2014-02-14 09:20:33 +0000 |
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committer | Alexey Samsonov <samsonov@google.com> | 2014-02-14 09:20:33 +0000 |
commit | 53aa4fda49f94920139300227786ac47c393f1ce (patch) | |
tree | 6d022d04ee279fe1afd89668f346e28a9e3e1559 /lib/builtins/multi3.c | |
parent | 6d999e478fecb10dc43f20b85385d25cc239db0a (diff) |
Move original compiler-rt functions (libgcc replacement) to lib/builtins directory
git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@201393 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/builtins/multi3.c')
-rw-r--r-- | lib/builtins/multi3.c | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/lib/builtins/multi3.c b/lib/builtins/multi3.c new file mode 100644 index 000000000..0b8730f08 --- /dev/null +++ b/lib/builtins/multi3.c @@ -0,0 +1,58 @@ +/* ===-- multi3.c - Implement __multi3 -------------------------------------=== + * + * The LLVM Compiler Infrastructure + * + * This file is dual licensed under the MIT and the University of Illinois Open + * Source Licenses. See LICENSE.TXT for details. + * + * ===----------------------------------------------------------------------=== + + * This file implements __multi3 for the compiler_rt library. + * + * ===----------------------------------------------------------------------=== + */ + +#include "int_lib.h" + +#if __x86_64 + +/* Returns: a * b */ + +static +ti_int +__mulddi3(du_int a, du_int b) +{ + twords r; + const int bits_in_dword_2 = (int)(sizeof(di_int) * CHAR_BIT) / 2; + const du_int lower_mask = (du_int)~0 >> bits_in_dword_2; + r.s.low = (a & lower_mask) * (b & lower_mask); + du_int t = r.s.low >> bits_in_dword_2; + r.s.low &= lower_mask; + t += (a >> bits_in_dword_2) * (b & lower_mask); + r.s.low += (t & lower_mask) << bits_in_dword_2; + r.s.high = t >> bits_in_dword_2; + t = r.s.low >> bits_in_dword_2; + r.s.low &= lower_mask; + t += (b >> bits_in_dword_2) * (a & lower_mask); + r.s.low += (t & lower_mask) << bits_in_dword_2; + r.s.high += t >> bits_in_dword_2; + r.s.high += (a >> bits_in_dword_2) * (b >> bits_in_dword_2); + return r.all; +} + +/* Returns: a * b */ + +ti_int +__multi3(ti_int a, ti_int b) +{ + twords x; + x.all = a; + twords y; + y.all = b; + twords r; + r.all = __mulddi3(x.s.low, y.s.low); + r.s.high += x.s.high * y.s.low + x.s.low * y.s.high; + return r.all; +} + +#endif /* __x86_64 */ |