On Fri, Oct 28, 2022 at 2:27 PM Richard Biener <richard.guent...@gmail.com> wrote: > > On Fri, Oct 28, 2022 at 11:11 AM Eric Botcazou via Gcc-patches > <gcc-patches@gcc.gnu.org> wrote: > > > > Hi, > > > > the following change: > > > > 2021-07-28 Bin Cheng <bin.ch...@linux.alibaba.com> > > > > * alias.c (init_alias_analysis): Don't skip prologue/epilogue. > > > > broke the alias analysis for the hard frame pointer (when it is used as a > > frame pointer, i.e. when the frame pointer is not eliminated) described in > > the > > large comment at the top of the file, because static_reg_base_value is set > > for > > it and, consequently, new_reg_base_value too. So when the instruction > > saving > > the stack pointer into the hard frame pointer in the prologue is processed, > > it > > is viewed as a second set of the hard frame pointer and to a different value > > by record_set, which then resets new_reg_base_value to 0 and the game is > > over. > > > > This e.g. hampers the performance of the var-tracking RTL pass for > > parameters > > passed on the stack like on x86, leading to regressions when debugging, but > > code generation is very likely affected too. > > > > Bootstrapped/regtested on x86-64/Linux, OK for mainline and 12 branch? > > OK for trunk and 12 after a while of burn-in.
Oh, do you have a testcase suitable for the testsuite? > Thanks, > Richard. > > > > > 2022-10-28 Eric Botcazou <ebotca...@adacore.com> > > > > * alias.cc (init_alias_analysis): Do not record sets to the hard > > frame pointer if the frame pointer has not been eliminated. > > > > -- > > Eric Botcazou
