PStore.sol

library PStore {
  function pload(uint256 memoryStart, uint256 slotStart, uint256 slotCount) internal view {
      assembly {
          function run(memoryEnd, slot, memoryCursor) {
              for {} xor(memoryCursor, memoryEnd) {} {
                  mstore(memoryCursor, sload(slot))

                  // memoryCursor is already at the top.
                  memoryCursor := add(memoryCursor, 0x20)

                  // slot is immediately below memoryCursor.
                  slot := add(slot, 1)
              }
          }

          if shr(251, slotCount) { invalid() }
          run(add(memoryStart, shl(5, slotCount)), slotStart, memoryStart)
      }
  }

  function pstore(uint256 memoryStart, uint256 slotStart, uint256 slotCount) internal {
      assembly {
          function run(memoryEnd, slot, memoryCursor) {
              for {} xor(memoryCursor, memoryEnd) {} {
                  sstore(slot, mload(memoryCursor))
                  memoryCursor := add(memoryCursor, 0x20)
                  slot := add(slot, 1)
              }
          }

          if shr(251, slotCount) { invalid() }
          run(add(memoryStart, shl(5, slotCount)), slotStart, memoryStart)
      }
  }
}