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Diffstat (limited to 'contrib/compiler-rt/lib/clzdi2.c')
-rw-r--r-- | contrib/compiler-rt/lib/clzdi2.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/contrib/compiler-rt/lib/clzdi2.c b/contrib/compiler-rt/lib/clzdi2.c new file mode 100644 index 0000000..c281945 --- /dev/null +++ b/contrib/compiler-rt/lib/clzdi2.c @@ -0,0 +1,30 @@ +/* ===-- clzdi2.c - Implement __clzdi2 -------------------------------------=== + * + * 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 __clzdi2 for the compiler_rt library. + * + * ===----------------------------------------------------------------------=== + */ +#include "abi.h" + +#include "int_lib.h" + +/* Returns: the number of leading 0-bits */ + +/* Precondition: a != 0 */ + +COMPILER_RT_ABI si_int +__clzdi2(di_int a) +{ + dwords x; + x.all = a; + const si_int f = -(x.s.high == 0); + return __builtin_clz((x.s.high & ~f) | (x.s.low & f)) + + (f & ((si_int)(sizeof(si_int) * CHAR_BIT))); +} |