diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/qemu/bitops.h | 55 | ||||
| -rw-r--r-- | include/qemu/hbitmap.h | 2 | ||||
| -rw-r--r-- | include/qemu/host-utils.h | 26 |
3 files changed, 23 insertions, 60 deletions
diff --git a/include/qemu/bitops.h b/include/qemu/bitops.h index 74e14e5724..8b88791862 100644 --- a/include/qemu/bitops.h +++ b/include/qemu/bitops.h @@ -13,6 +13,7 @@ #define BITOPS_H #include "qemu-common.h" +#include "host-utils.h" #define BITS_PER_BYTE CHAR_BIT #define BITS_PER_LONG (sizeof (unsigned long) * BITS_PER_BYTE) @@ -23,41 +24,29 @@ #define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long)) /** - * bitops_ffs - find first bit in word. + * bitops_ctzl - count trailing zeroes in word. * @word: The word to search * - * Undefined if no bit exists, so code should check against 0 first. + * Returns -1 if no bit exists. Note that compared to the C library + * routine ffsl, this one returns one less. */ -static unsigned long bitops_ffsl(unsigned long word) +static unsigned long bitops_ctzl(unsigned long word) { - int num = 0; +#if QEMU_GNUC_PREREQ(3, 4) + return __builtin_ffsl(word) - 1; +#else + if (!word) { + return -1; + } -#if LONG_MAX > 0x7FFFFFFF - if ((word & 0xffffffff) == 0) { - num += 32; - word >>= 32; - } + if (sizeof(long) == 4) { + return ctz32(word); + } else if (sizeof(long) == 8) { + return ctz64(word); + } else { + abort(); + } #endif - if ((word & 0xffff) == 0) { - num += 16; - word >>= 16; - } - if ((word & 0xff) == 0) { - num += 8; - word >>= 8; - } - if ((word & 0xf) == 0) { - num += 4; - word >>= 4; - } - if ((word & 0x3) == 0) { - num += 2; - word >>= 2; - } - if ((word & 0x1) == 0) { - num += 1; - } - return num; } /** @@ -99,14 +88,14 @@ static inline unsigned long bitops_flsl(unsigned long word) } /** - * ffz - find first zero in word. + * cto - count trailing ones in word. * @word: The word to search * - * Undefined if no zero exists, so code should check against ~0UL first. + * Returns -1 if all bit are set. */ -static inline unsigned long ffz(unsigned long word) +static inline unsigned long bitops_ctol(unsigned long word) { - return bitops_ffsl(~word); + return bitops_ctzl(~word); } /** diff --git a/include/qemu/hbitmap.h b/include/qemu/hbitmap.h index 73f5d1d8d3..250de03b03 100644 --- a/include/qemu/hbitmap.h +++ b/include/qemu/hbitmap.h @@ -170,7 +170,7 @@ static inline int64_t hbitmap_iter_next(HBitmapIter *hbi) /* The next call will resume work from the next bit. */ hbi->cur[HBITMAP_LEVELS - 1] = cur & (cur - 1); - item = ((uint64_t)hbi->pos << BITS_PER_LEVEL) + ffsl(cur) - 1; + item = ((uint64_t)hbi->pos << BITS_PER_LEVEL) + bitops_ctzl(cur); return item << hbi->granularity; } diff --git a/include/qemu/host-utils.h b/include/qemu/host-utils.h index 2a32be4cc0..81c9a754ae 100644 --- a/include/qemu/host-utils.h +++ b/include/qemu/host-utils.h @@ -26,7 +26,6 @@ #define HOST_UTILS_H 1 #include "qemu/compiler.h" /* QEMU_GNUC_PREREQ */ -#include <string.h> /* ffsl */ #if defined(__x86_64__) #define __HAVE_FAST_MULU64__ @@ -238,29 +237,4 @@ static inline int ctpop64(uint64_t val) #endif } -/* glibc does not provide an inline version of ffsl, so always define - * ours. We need to give it a different name, however. - */ -#ifdef __GLIBC__ -#define ffsl qemu_ffsl -#endif -static inline int ffsl(long val) -{ - if (!val) { - return 0; - } - -#if QEMU_GNUC_PREREQ(3, 4) - return __builtin_ctzl(val) + 1; -#else - if (sizeof(long) == 4) { - return ctz32(val) + 1; - } else if (sizeof(long) == 8) { - return ctz64(val) + 1; - } else { - abort(); - } -#endif -} - #endif |