villa gogh wrote: > hi > now i'm trying to construct def-use chain after the PASS_LEAF_REGS. > for the ssa form structure has been destoried during the former > passes. > I have found that gcc provides a way to build the def-use chain in the > PASS_REGRENAME, but it only contains the defs and uses all in one > basic block.
No, don't look at those. Instead look at fwprop.c which uses use-def chains -- DU chains are the same but they are computed with df_chain_add_problem (DF_DU_CHAIN); instead of df_chain_add_problem (DF_UD_CHAIN); before df_analyze. fwprop accesses use-def chains by using DF_REF_CHAIN (use); def-use chains are the same but the DF_REF_CHAIN macro is used with a def argument instead. Paolo
