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author | bstarynk <bstarynk@138bc75d-0d04-0410-961f-82ee72b054a4> | 2010-12-01 13:15:28 +0000 |
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committer | bstarynk <bstarynk@138bc75d-0d04-0410-961f-82ee72b054a4> | 2010-12-01 13:15:28 +0000 |
commit | feeb6596a18e42225d0f25a03b35c564d9a10ebb (patch) | |
tree | 7e6fb5e50aa3f901480410fc04ba058b6f0e94fa /gcc/hwint.c | |
parent | acc16a01c06415b69d0a54c9e86f4ec72665ee54 (diff) | |
download | gcc-feeb6596a18e42225d0f25a03b35c564d9a10ebb.tar.gz |
2010-12-01 Basile Starynkevitch <basile@starynkevitch.net>
MELT branch merged with trunk rev 167323
2010-12-01 Basile Starynkevitch <basile@starynkevitch.net>
{{merged with trunk rev 167323, and regenerated}}
* melt/generated/warmelt-normatch.0+01.c: Regenerate.
* melt/generated/warmelt-first.0.c: Regenerate.
* melt/generated/warmelt-normal.0.c: Regenerate.
* melt/generated/warmelt-normatch.0+03.c: Regenerate.
* melt/generated/warmelt-macro.0.c: Regenerate.
* melt/generated/warmelt-outobj.0.c: Regenerate.
* melt/generated/warmelt-genobj.0.c: Regenerate.
* melt/generated/warmelt-normal.0+01.c: Regenerate.
* melt/generated/warmelt-normal.0+02.c: Regenerate.
* melt/generated/warmelt-base.0.c: Regenerate.
* melt/generated/warmelt-normatch.0.c: Regenerate.
* melt/generated/warmelt-genobj.0+01.c: Regenerate.
* melt/generated/warmelt-genobj.0+03.c: Regenerate.
* melt/generated/warmelt-genobj.0+04.c: Regenerate.
* melt/generated/warmelt-debug.0.c: Regenerate.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/melt-branch@167327 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/hwint.c')
-rw-r--r-- | gcc/hwint.c | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/gcc/hwint.c b/gcc/hwint.c new file mode 100644 index 00000000000..85c1326bdde --- /dev/null +++ b/gcc/hwint.c @@ -0,0 +1,100 @@ +/* Operations on HOST_WIDE_INT. + Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, + 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 + Free Software Foundation, Inc. + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify it under +the terms of the GNU General Public License as published by the Free +Software Foundation; either version 3, or (at your option) any later +version. + +GCC is distributed in the hope that it will be useful, but WITHOUT ANY +WARRANTY; without even the implied warranty of MERCHANTABILITY or +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +You should have received a copy of the GNU General Public License +along with GCC; see the file COPYING3. If not see +<http://www.gnu.org/licenses/>. */ + +#include "config.h" +#include "system.h" + +#if GCC_VERSION < 3004 + +/* The functions clz_hwi, ctz_hwi, ffs_hwi, floor_log2 and exact_log2 + are defined as inline functions in hwint.h if GCC_VERSION >= 3004. + The definitions here are used for older versions of GCC and non-GCC + bootstrap compilers. */ + +/* Given X, an unsigned number, return the largest int Y such that 2**Y <= X. + If X is 0, return -1. */ + +int +floor_log2 (unsigned HOST_WIDE_INT x) +{ + int t = 0; + + if (x == 0) + return -1; + + if (HOST_BITS_PER_WIDE_INT > 64) + if (x >= (unsigned HOST_WIDE_INT) 1 << (t + 64)) + t += 64; + if (HOST_BITS_PER_WIDE_INT > 32) + if (x >= ((unsigned HOST_WIDE_INT) 1) << (t + 32)) + t += 32; + if (x >= ((unsigned HOST_WIDE_INT) 1) << (t + 16)) + t += 16; + if (x >= ((unsigned HOST_WIDE_INT) 1) << (t + 8)) + t += 8; + if (x >= ((unsigned HOST_WIDE_INT) 1) << (t + 4)) + t += 4; + if (x >= ((unsigned HOST_WIDE_INT) 1) << (t + 2)) + t += 2; + if (x >= ((unsigned HOST_WIDE_INT) 1) << (t + 1)) + t += 1; + + return t; +} + +/* Return the logarithm of X, base 2, considering X unsigned, + if X is a power of 2. Otherwise, returns -1. */ + +int +exact_log2 (unsigned HOST_WIDE_INT x) +{ + if (x != (x & -x)) + return -1; + return floor_log2 (x); +} + +/* Given X, an unsigned number, return the number of least significant bits + that are zero. When X == 0, the result is the word size. */ + +int +ctz_hwi (unsigned HOST_WIDE_INT x) +{ + return x ? floor_log2 (x & -x) : HOST_BITS_PER_WIDE_INT; +} + +/* Similarly for most significant bits. */ + +int +clz_hwi (unsigned HOST_WIDE_INT x) +{ + return HOST_BITS_PER_WIDE_INT - 1 - floor_log2(x); +} + +/* Similar to ctz_hwi, except that the least significant bit is numbered + starting from 1, and X == 0 yields 0. */ + +int +ffs_hwi (unsigned HOST_WIDE_INT x) +{ + return 1 + floor_log2 (x & -x); +} + +#endif /* GCC_VERSION < 3004 */ |