2e broadsword
I can tell you the stats for the 2e version of the broadsword.
speed factor of 5, (or whatever a longsword was, they were the same); damage vs. small/medium creatures = 2d4; damage versus large/<and up> creatures = 1d6+1.
I personally changed the dam. to large creatures to be 1d8+1, to make it slightly on more even ground with the longsword, but in truth, the weapon is meant to be worse than a longsword in many ways.
If I were to introduce one into a 3e campaign, I would probably make it a 2d4 martial weapon, one-handed, that simply did 2x damage on a natural 20. It would cost less than a longsword too.