[Bug target/114567] rs6000: explicit _Float128 doesn't generate optimal code

[linkw at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114567

--- Comment #1 from Kewen Lin  ---
This is power8 LE specific, for KFmode its mov expander calls
rs6000_emit_le_vsx_move, so it's with V1TI subreg, then rs6000 specific pass
swaps generate one MEM with AND -16, which make combine unable to optimize it
with that *signbit2_dm_mem pattern due to mode_dependent_address_p
returning false always for AND. Although it looks to me we can extend
mode_dependent_address_p to consider the to-mode in that context, it's still
sub-optimal due to the existence of AND -16, which result in an explicit "and"
then.

[Bug target/114567] rs6000: explicit _Float128 doesn't generate optimal code

[linkw at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114567

Kewen Lin  changed:

   What|Removed |Added

   Target Milestone|--- |15.0
   Keywords||missed-optimization
 Target||powerpc64*-linux-gnu
   Last reconfirmed||2024-04-03
 Status|UNCONFIRMED |ASSIGNED
 Ever confirmed|0   |1
   Assignee|unassigned at gcc dot gnu.org  |linkw at gcc dot gnu.org