Class and struct members are required by the standard to be stored in memory in the same order in which they are declared. So in your example, it wouldn’t be possible for d to appear before b. Also, most architectures prefer that multi-byte types are aligned on 4- or 8-byte boundaries. So all the compiler … Read more
Here is a go at the implementation of your algorithm. I tweaked it quite a bit, but I think it does basically the same thing. Bounding circles I used a trick to make the computation more regular. Instead of segments defining the bounding box, I used circles with “infinite” radii, that can be considered a … Read more
As the comment says, we’re going to pack the age, gender and height into 15 bits, of the format: AAAAAAAGHHHHHHH Let’s start with this part: (age << 8) To start with, age has this format: age = 00000000AAAAAAA where each A can be 0 or 1. << 8 moves the bits 8 places to the … Read more
I found the solution from the second comment you provided, Trengot, thanks. It turns out that I had some dangling blobs, which were in .git/objects/17 and hence triggering the packing: $ git fsck dangling blob d9ff0aeac4aa8b4e0907daed675ebf60278bc977 dangling blob dbff2d073741f9775c815d4a3c623736af224dad dangling blob e1ffbab1c5b985cd1cd3bc0281075ea2ed80744a dangling blob fdff59878ccb3a75689f4acca615cfb635288774 This cleaned them up: $ git gc –prune=now Be aware, … Read more
Padding aligns structure members to “natural” address boundaries – say, int members would have offsets, which are mod(4) == 0 on 32-bit platform. Padding is on by default. It inserts the following “gaps” into your first structure: struct mystruct_A { char a; char gap_0[3]; /* inserted by compiler: for alignment of b */ int b; … Read more
See this page on the ARC project for a survey of solutions, there is a trade-off between implementation complexity/time and optimality, but there is a wide range of algorithms to choose from. Here’s an extract of the algorithms: First-Fit Decreasing Height (FFDH) algorithm FFDH packs the next item R (in non-increasing height) on the first … Read more