Rémi Bernon (@rbernon) commented about dlls/ntdll/heap.c:
- log = b - FREE_LIST_LINEAR_BITS + 1;
- block = ( log << FREE_LIST_LINEAR_BITS ) + linear;
- return min( block, NB_FREE_LISTS - 1 );
+}
+static size_t get_free_list_block_size( unsigned long index ) +{
- unsigned long log = 1 << FREE_LIST_LINEAR_BITS;
- unsigned long linear = index & FREE_LIST_LINEAR_MASK;
- if ( ( index >> FREE_LIST_LINEAR_BITS ) == 0 )
return index * BLOCK_ALIGN;- return ( ( log + linear ) << ( ( index >> FREE_LIST_LINEAR_BITS ) - 1 ) ) * BLOCK_ALIGN;
+}
```suggestion:-32+0 static SIZE_T get_free_list_block_size( UINT index ) { UINT linear = index & FREE_LIST_LINEAR_MASK, shift = index >> FREE_LIST_LINEAR_BITS; if (shift) linear = (linear + (1 << FREE_LIST_LINEAR_BITS)) << (shift - 1); return linear * BLOCK_ALIGN; }
static UINT get_free_list_index( SIZE_T block_size ) { UINT linear, shift; DWORD bit;
if (block_size >= get_free_list_block_size( FREE_LIST_COUNT - 1 )) return FREE_LIST_COUNT - 1;
block_size /= BLOCK_ALIGN; if (!BitScanReverse( &bit, block_size ) || bit < FREE_LIST_LINEAR_BITS) return block_size;
/* the highest bit is always set, ignore it and encode the next FREE_LIST_LINEAR_BITS bits * as a linear scale, combined with the shift as a log scale, in the free list index. */ shift = bit - FREE_LIST_LINEAR_BITS + 1; linear = (block_size - (1 << bit)) >> (shift - 1);
return (shift << FREE_LIST_LINEAR_BITS) + (linear & FREE_LIST_LINEAR_MASK); } ```
We can use `get_free_list_block_size` to early reject large cases, and make the rest a little bit simpler.
Also note that the style has spaces only in function and macros parentheses. And like @iamahuman suggested, the code around uses win32 types, so prefer `ULONG` / `UINT` over unsigned long, and `SIZE_T` instead of `size_t`.