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| author | rguenth <rguenth@138bc75d-0d04-0410-961f-82ee72b054a4> | 2010-08-04 09:15:51 +0000 |
|---|---|---|
| committer | rguenth <rguenth@138bc75d-0d04-0410-961f-82ee72b054a4> | 2010-08-04 09:15:51 +0000 |
| commit | d41e3320812c9a849b32c60aa7c7b4f4de62995f (patch) | |
| tree | 048c888ac173b7ff5e353331c625f86b580387ee /gcc/double-int.c | |
| parent | 0be9eeeeffec9dcc76041dd8d019e9782e28569c (diff) | |
| download | gcc-d41e3320812c9a849b32c60aa7c7b4f4de62995f.tar.gz | |
2010-08-04 Richard Guenther <rguenther@suse.de>
* Makefile.in (double-int.o): Add $(TOPLEV_H) dependency.
* double-int.h (double_int_ctz): Declare.
* double-int.c (double_int_ctz): New function.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@162859 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/double-int.c')
| -rw-r--r-- | gcc/double-int.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/gcc/double-int.c b/gcc/double-int.c index 924e91b6c90..29e720b2919 100644 --- a/gcc/double-int.c +++ b/gcc/double-int.c @@ -22,6 +22,7 @@ along with GCC; see the file COPYING3. If not see #include "coretypes.h" #include "tm.h" #include "tree.h" +#include "toplev.h" /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring overflow. Suppose A, B and SUM have the same respective signs as A1, B1, @@ -850,6 +851,26 @@ double_int_setbit (double_int a, unsigned bitpos) return a; } +/* Count trailing zeros in A. */ +int +double_int_ctz (double_int a) +{ + unsigned HOST_WIDE_INT w = a.low ? a.low : (unsigned HOST_WIDE_INT) a.high; + unsigned bits = a.low ? 0 : HOST_BITS_PER_WIDE_INT; + if (!w) + return HOST_BITS_PER_DOUBLE_INT; +#if (GCC_VERSION >= 3004) + bits += CTZ_HWI (w); +#else + while (!(w & 1)) + { + w >>= 1; + bits += 1; + } +#endif + return bits; +} + /* Shift A left by COUNT places keeping only PREC bits of result. Shift right if COUNT is negative. ARITH true specifies arithmetic shifting; otherwise use logical shift. */ |