> > > > > Hi folks. > > > > While investigating a regression from the V_MUST_DEF removal on mem-ssa, > > I've noticed that we were missing out on optimization of certain > > stores to complex types (on mainline). > > > > For example, here: > > > > _Complex int t = 0; > > __real__ t = 2; > > __imag__ t = 2; > > > > we end up with: > > > > # t_2 = V_MUST_DEF <t_1>; > > t = __complex__ (0, 0); > > # t_3 = V_MAY_DEF <t_2>; > > REALPART_EXPR <t> = 2; > > # t_4 = V_MAY_DEF <t_3>; > > IMAGPART_EXPR <t> = 2; > > > > When we really should be decomposing the field stores into SFTs, like this: > > > > # SFT.0_3 = V_MUST_DEF <SFT.0_1>; > > # SFT.1_4 = V_MUST_DEF <SFT.1_2>; > > t = __complex__ (0, 0); > > # SFT.1_5 = V_MUST_DEF <SFT.1_4>; > > REALPART_EXPR <t> = 2; > > # SFT.0_6 = V_MUST_DEF <SFT.0_3>; > > IMAGPART_EXPR <t> = 2; > > Relooking at the orginal testcase which actually has a read in it, This > seems like the wrong approach. Can you figure out why write_only is not > being set to false for the orginal testcase (and not the reduced one)?
I should also mention on the mainline, we get the decomposing for the orginal testcase which means this is a bug only on the MEM-SSA branch. -- Pinski
