[Bug target/119847] [13/14/15 Regression] RISC-V:GCC fail to optimize repeated patterns in volatile operations

[fanghuaqi at vip dot qq.com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119847

--- Comment #3 from Huaqi  ---
This issue still existed in gcc truck(16) version, will it be optimized, or is
there any patch?

[Bug target/119847] [13/14/15 Regression] RISC-V:GCC fail to optimize repeated patterns in volatile operations

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119847

Andrew Pinski  changed:

   What|Removed |Added

 CC||fanghuaqi at vip dot qq.com

--- Comment #2 from Andrew Pinski  ---
*** Bug 120344 has been marked as a duplicate of this bug. ***

[Bug target/119847] [13/14/15 Regression] RISC-V:GCC fail to optimize repeated patterns in volatile operations

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119847

Andrew Pinski  changed:

   What|Removed |Added

 Ever confirmed|0   |1
   Last reconfirmed||2025-04-17
   Target Milestone|--- |13.4
 Status|UNCONFIRMED |NEW
Summary|RISC-V:GCC fail to optimize |[13/14/15 Regression]
   |repeated patterns in|RISC-V:GCC fail to optimize
   |volatile operations |repeated patterns in
   ||volatile operations

--- Comment #1 from Andrew Pinski  ---
Confirmed.

The problem is at combine we recreate the full constant into an insn:
(insn 8 3 9 2 (set (reg/f:DI 141)
(const_int 4161536696 [0xf80c02b8])) "/app/example.cpp":5:23 275
{*mvconst_internal}
 (nil))
...
(insn 15 12 16 2 (set (reg/f:DI 146)
(const_int 4161536692 [0xf80c02b4])) "/app/example.cpp":5:23 275
{*mvconst_internal}
 (nil))


Which caused by r13-4907-g2e886eef7f2b5a .