On Tue, Sep 15, 2020 at 10:49:43AM +0930, Alan Modra wrote: > This small patch to rs6000_rtx_const considerably improves code
(_costs) > generated for large constants in 64-bit code, teaching gcc that it is > better to load a constant from memory than to generate a sequence of > up to five dependent instructions. Note that the rs6000 backend does > generate large constants as loads from memory at expand time but > optimisation passes replace them with SETs of the value due to not > having correct costs. > > PR 94393 > * config/rs6000/rs6000.c (rs6000_rtx_costs): Cost multi-insn > constants. Okay for trunk. Note that some p10 insns take a floating point immediate, but those need to be handled specially anyway. Thanks! Segher
