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Add size class computation capability.

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Add size class computation capability, currently used only as validation
of the size class lookup tables.  Generalize the size class spacing used
for bins, for eventual use throughout the full range of allocation
sizes.
This commit is contained in:
Jason Evans 2014-05-28 16:11:55 -07:00
parent 99118622ff
commit d04047cc29
9 changed files with 462 additions and 91 deletions
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47
include/jemalloc/internal/util.h
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@ -110,6 +110,7 @@ void malloc_printf(const char *format, ...)
#ifndef JEMALLOC_ENABLE_INLINE
size_t pow2_ceil(size_t x);
size_t lg_floor(size_t x);
void set_errno(int errnum);
int get_errno(void);
#endif
@ -133,6 +134,52 @@ pow2_ceil(size_t x)
return (x);
}
#if (defined(__i386__) || defined(__amd64__) || defined(__x86_64__))
JEMALLOC_INLINE size_t
lg_floor(size_t x)
{
size_t ret;
asm ("bsr %1, %0"
: "=r"(ret) // Outputs.
: "r"(x) // Inputs.
);
return (ret);
}
#elif (defined(JEMALLOC_HAVE_BUILTIN_CLZ))
JEMALLOC_INLINE size_t
lg_floor(size_t x)
{
#if (LG_SIZEOF_PTR == LG_SIZEOF_INT)
return ((8 << LG_SIZEOF_PTR - 1) - __builtin_clz(x));
#elif (LG_SIZEOF_PTR == LG_SIZEOF_LONG)
return ((8 << LG_SIZEOF_PTR - 1) - __builtin_clzl(x));
#else
# error "Unsupported type sizes for lg_floor()"
#endif
}
#else
JEMALLOC_INLINE size_t
lg_floor(size_t x)
{
x |= (x >> 1);
x |= (x >> 2);
x |= (x >> 4);
x |= (x >> 8);
x |= (x >> 16);
#if (LG_SIZEOF_PTR == 3 && LG_SIZEOF_PTR == LG_SIZEOF_LONG)
x |= (x >> 32);
return (65 - ffsl(~x));
#elif (LG_SIZEOF_PTR == 2)
return (33 - ffs(~x));
#else
# error "Unsupported type sizes for lg_floor()"
#endif
}
#endif
/* Sets error code */
JEMALLOC_INLINE void
set_errno(int errnum)