[Bug target/84627] powerpc excess padding generated for POWER9 target

[npiggin at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84627

Nicholas Piggin <npiggin at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|INVALID                     |FIXED

--- Comment #4 from Nicholas Piggin <npiggin at gmail dot com> ---
After some more discussion and testing, it was determined that for POWER9, 16
bytes of padding is sufficient for these small loops and was adjusted.

https://gcc.gnu.org/viewcvs/gcc?view=revision&revision=258260

Author:         segher
Date:   Mon Mar 5 19:11:54 2018 UTC (3 hours, 27 minutes ago)
Log Message:

rs6000: Don't align tiny loops to 32 bytes for POWER9

For POWER4..POWER8 we align loops of 5..8 instructions to 32 bytes
(instead of to 16 bytes) because that executes faster.  This is no
longer the case on POWER9, so we can just as well only align to 16
bytes.


        * config/rs6000/rs6000.c (rs6000_loop_align): Don't align tiny loops
        to 32 bytes when compiling for POWER9.