IIRC, icc does not normally pad structures, since x86-64 supports unaligned loads fairly well. xlc on POWER generally tries to do what kazinator stated above b

IIRC, icc does not normally pad structures, since x86-64 supports unaligned loads fairly well. xlc on POWER generally tries to do what kazinator stated above because unaligned loads are expensive, if even possible, on those platforms.