[Bug target/117007] Poor optimization for small vector constants needed for vector shift/rotate/mask generation

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117007

--- Comment #11 from Steven Munroe <munroesj at gcc dot gnu.org> ---
Created attachment 59560
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=59560&action=edit
Test cases for vec_splats(signed chat) on -mcpu=power9

for and valid char value I would expect for example vec_splats ((signed char)
16)
to generate single xxspltib vs34,16.

But I am seeing:
0000000000000020 <test_splat6_s8_16>:
      20:       d1 42 40 f0     xxspltib vs34,8
      24:       00 10 42 10     vaddubm v2,v2,v2