  The chemical abundances measured in stars of the Galactic bulge offer an
unique opportunity to test galaxy formation models as well as impose strong
constraints on the history of star formation and stellar nucleosynthesis.
  The aims of this paper are to compare abundance predictions from a detailed
chemical evolution model for the bulge with the newest data. Some of the
predictions have already appeared on previous paper (O, Mg, Si, S and Ca) but
some other predictions are new (Ba, Cr and Ti).
  We compute several chemical evolution models by adopting different initial
mass functions for the Galactic bulge and then compare the results to new data
including both giants and dwarf stars in the bulge. In this way we can impose
strong constraints on the star formation history of the bulge.
  We find that in order to reproduce at best the metallicity distribution
function one should assume a flat IMF for the bulge not steeper than the
Salpeter one. The initial mass function derived for the solar vicinity provides
instead a very poor fit to the data. The [el/Fe] vs. [Fe/H] relations in the
bulge are well reproduced by a very intense star formation rate and a flat IMF
as in the case of the stellar metallicity distribution. Our model predicts that
the bulge formed very quickly with the majority of stars formed inside the
first 0.5 Gyr.
  Our results strongly suggest that the new data, and in particular the MDF of
the bulge, confirm what concluded before and in particular that the bulge
formed very fast, from gas shed by the halo, and that the initial mass function
was flatter than in the solar vicinity and in the disk, although not so flat as
previously thought. Finally, our model can also reproduce the decrease of the
[O/Mg] ratio for [Mg/H] > 0 in the bulge, which is confirmed by the new data
and interpreted as due to mass loss in massive stars.
