[Bug rtl-optimization/80791] [8 regression] test case gcc.dg/sms-1.c fail2 starting with r247885

["amker at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80791

--- Comment #3 from amker at gcc dot gnu.org ---
(In reply to Aldy Hernandez from comment #2)
> Confirmed.  Any update on this amker?
> 
> Started with:
> 
> commit a9b41911523c1db8042f1f3ffff8d1ed814326ef
> Author: amker <amker@138bc75d-0d04-0410-961f-82ee72b054a4>
> Date:   Thu May 11 09:31:18 2017 +0000
> 
>             * tree-ssa-loop-ivopts.c (get_loop_invariant_expr): Simplify.
>             (adjust_setup_cost): New parameter supporting round up
> adjustment.
>             (struct address_cost_data): Delete.
>             (force_expr_to_var_cost): Don't bound cost with spill_cost.
>             (split_address_cost, ptr_difference_cost): Delete.
>             (difference_cost, compare_aff_trees, record_inv_expr): Delete.
>             (struct ainc_cost_data): New struct.
>             (get_address_cost_ainc): New function.
>             (get_address_cost, get_computation_cost): Reimplement.
>             (determine_group_iv_cost_address): Record inv_expr for all uses
> of
>             a group.
>             (determine_group_iv_cost_cond): Call get_loop_invariant_expr.
>             (iv_ca_has_deps): Reimplemented to ...
>             (iv_ca_more_deps): ... this.  Check if NEW_CP introduces more
> deps
>             than OLD_CP.
>             (iv_ca_extend): Call iv_ca_more_deps.
>     
>     
>     git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@247885
> 138bc75d-0d04-0410-96
> 1f-82ee72b054a4

Hmm, could you please provide the configuration of GCC?  I tried to reproduce
with below configuration:
../gcc/configure --build=x86_64-linux-gnu --host=x86_64-linux-gnu
--target=powerpc-elf --prefix=/.../target/ --disable-decimal-float
--disable-libffi --disable-libgomp --disable-libmudflap --disable-libssp
--disable-libstdcxx-pch --disable-nls --disable-shared --disable-threads
--disable-tls --with-gnu-as --with-gnu-ld --with-newlib --with-headers=yes
--with-sysroot=/.../target/powerpc-elf --with-host-libstdcxx='-static-libgcc
-Wl,-Bstatic,-lstdc++,-Bdynamic -lm' --enable-languages=c,c++,lto

The result GCC always fails SMS on power6, even with r247884; and it always
succeeds SMS on power7.  Like:
./powerpc-elf-gcc -O2 -fmodulo-sched -fmodulo-sched-allow-regmoves
-fdump-rtl-sms sms-1.c -o sms-1.S -S -mcpu=power7
./powerpc-elf-gcc -O2 -fmodulo-sched -fmodulo-sched-allow-regmoves
-fdump-rtl-sms sms-1.c -o sms-1.S -S -mcpu=power6

Thanks.