This is my current 4.7 auto-inc-dec.c patch. I submitted an RFC in July:

http://article.gmane.org/gmane.comp.gcc.patches/241779/

and updated the patch in line with the feedback I got. Steven Bosscher sent some very useful comments in private email, so the update deals with those as well as Bernd's public ones.

If we do go ahead with this rewrite, it depends on the A9 pipeline description changes. I submitted some A8 and A9 changes here:

http://article.gmane.org/gmane.comp.gcc.patches/244238/ http://article.gmane.org/gmane.comp.gcc.patches/244242/

but because I later noticed that the A9 didn't behave quite as I thought, I decided not to apply them. Ramana asked around internally about what the A9 actually does (thanks) and had some ideas.

The patch also relies on the MEM rtx_costs patch that I just posted:

http://lists.linaro.org/pipermail/linaro-toolchain/2011-December/001944.html

Richard

gcc/ * Makefile.in (auto-inc-dec.o): Depends on $(OPTABS_H) and addresses.h. * auto-inc-dec.c: Rewrite.

Index: gcc/Makefile.in =================================================================== --- gcc/Makefile.in 2011-12-07 11:43:29.549238252 +0000 +++ gcc/Makefile.in 2011-12-29 09:24:51.066303201 +0000 @@ -3145,7 +3145,8 @@ alloc-pool.o : alloc-pool.c $(CONFIG_H) auto-inc-dec.o : auto-inc-dec.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) \ $(TREE_H) $(RTL_H) $(TM_P_H) hard-reg-set.h $(BASIC_BLOCK_H) insn-config.h \ $(REGS_H) $(FLAGS_H) output.h $(FUNCTION_H) $(EXCEPT_H) $(DIAGNOSTIC_CORE_H) $(RECOG_H) \ - $(EXPR_H) $(TIMEVAR_H) $(TREE_PASS_H) $(DF_H) $(DBGCNT_H) $(TARGET_H) + $(EXPR_H) $(TIMEVAR_H) $(TREE_PASS_H) $(DF_H) $(DBGCNT_H) $(TARGET_H) \ + $(OPTABS_H) addresses.h cfg.o : cfg.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) $(RTL_H) $(FLAGS_H) \ $(REGS_H) hard-reg-set.h output.h $(DIAGNOSTIC_CORE_H) $(FUNCTION_H) $(EXCEPT_H) $(GGC_H) \ $(TM_P_H) $(TIMEVAR_H) $(OBSTACK_H) $(TREE_H) alloc-pool.h \