On 15/12/14 15:36, Jiong Wang wrote:
from the discussion here https://gcc.gnu.org/ml/gcc-patches/2014-11/msg01949.htmlthe other problem it exposed is the unnecessary clobber of register x19 which is a callee-saved register, then there are unnecessary push/pop in pro/epilogue. the reason comes from the following pattern: (define_insn "tb<optab><mode>1" (define_insn "cb<optab><mode>1" they always declare "(clobber (match_scratch:DI 3 "=r"))" while that register is used only when "get_attr_length (insn) == 8". actually, we could clobber CC register instead of scratch register to avoid wasting of general purpose registers. this patch fix this, and give slightly improvement on spec2k. bootstrap OK, no regression on aarch64 bare-metal. ok for trunk? the testcase included in the patch is for verification purpose only. it could verify the long branch situation, while because of the code is very big, it takes a couple of seconds to compile. will not commit it. gcc/ 2014-12-15 Ramana Radhakrishnan ramana.radhakrish...@arm.com Jiong Wang jiong.w...@arm.com * config/aarch64/aarch64.md (tb<optab><mode>1): Clobber CC reg instead of scratch reg. (cb<optab><mode>1): Likewise. * config/aarch64/iterators.md (bcond): New define_code_attr.
Ping~
