[Bug middle-end/33699] [5/6/7 regression] missing optimization on const addr area store

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=33699

Martin Sebor <msebor at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |msebor at gcc dot gnu.org
      Known to fail|                            |6.3.0, 7.0

--- Comment #23 from Martin Sebor <msebor at gcc dot gnu.org> ---
No progress in GCC 7.0 which emits the following code for powerpc64le at -O2
(-Os is slightly different but the same size):

0000000000000000 <f>:
   0:   00 00 20 39     li      r9,0
   4:   00 00 c0 38     li      r6,0
   8:   00 00 e0 38     li      r7,0
   c:   00 00 00 39     li      r8,0
  10:   00 00 40 39     li      r10,0
  14:   ad de 29 61     ori     r9,r9,57005
  18:   d0 fe c6 60     ori     r6,r6,65232
  1c:   d8 fe e7 60     ori     r7,r7,65240
  20:   e0 fe 08 61     ori     r8,r8,65248
  24:   e8 fe 4a 61     ori     r10,r10,65256
  28:   00 00 26 91     stw     r9,0(r6)
  2c:   00 00 27 91     stw     r9,0(r7)
  30:   00 00 28 91     stw     r9,0(r8)
  34:   00 00 2a 91     stw     r9,0(r10)
  38:   20 00 80 4e     blr


Clang in contrast emits the following more compact code:

0000000000000000 <f>:
   0:   00 00 60 3c     lis     r3,0
   4:   00 00 80 38     li      r4,0
   8:   01 00 a0 3c     lis     r5,1
   c:   ad de 63 60     ori     r3,r3,57005
  10:   d0 fe 84 60     ori     r4,r4,65232
  14:   d0 fe 65 90     stw     r3,-304(r5)
  18:   08 00 64 90     stw     r3,8(r4)
  1c:   10 00 64 90     stw     r3,16(r4)
  20:   18 00 64 90     stw     r3,24(r4)
  24:   20 00 80 4e     blr