Personal solution for CSAPP 2nd edition.

It works but is not the best.

• 2.55_show-byte
• 2.58_test-endian
• 2.59_combine-words
• 2.60_replace-byte
• 2.61_judge-word
• 2.62_int-shifts-is-logical
• 2.63_convert-right-shift
• 2.64_any-even-one
• 2.67_int-size-is-32
• 2.68_lower-bits
• 2.69_rotate-right
• 2.70_fits-bits
• 2.71_extract-byte
• 2.72_copy-int
• 2.73_saturating-add
• 2.74_subtract-overflow
• 2.75_unsigned-high-prod
• 2.77_divide-power2
• 2.78_mul5div8
• 2.79_fiveeights
• 2.91_float-absval
• 2.93_float-half
• 2.94_float-twice