[Bug target/115458] New: [15 regression] [RISC-V] ICE in lra_split_hard_reg_for, at lra-assigns.cc:1868 unable to find a register to spill

[Bug target/115458] New: [15 regression] [RISC-V] ICE in lra_split_hard_reg_for, at lra-assigns.cc:1868 unable to find a register to spill

[schwab@linux-m68k.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115458

            Bug ID: 115458
           Summary: [15 regression] [RISC-V] ICE in
                    lra_split_hard_reg_for, at lra-assigns.cc:1868 unable
                    to find a register to spill
           Product: gcc
           Version: 15.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: schwab@linux-m68k.org
  Target Milestone: ---
            Target: riscv64-*-*

Created attachment 58412
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=58412&action=edit
if_test.cc.ii

$ ./xgcc -B. -O2 -std=c++17 -march=rv64gcv1p0 if_test.cc.ii -S -fno-exceptions
/home/abuild/rpmbuild/BUILD/highway-1.2.0/hwy/tests/if_test.cc: In function
‘void hwy::N_RVV::TestIfNegativeThenNegOrUndefIfZero::operator()(T, D) [with T
= short int; D = hwy::N_RVV::Simd<short int, 4096, 3>]’:
/home/abuild/rpmbuild/BUILD/highway-1.2.0/hwy/tests/if_test.cc:268:3: error:
unable to find a register to spill
/home/abuild/rpmbuild/BUILD/highway-1.2.0/hwy/tests/if_test.cc:268:3: error:
this is the insn:
(insn 47 613 689 2 (set (reg:RVVM8HI 284)
        (if_then_else:RVVM8HI (unspec:RVVMF2BI [
                    (reg:RVVMF2BI 285 [orig:152 _19 ] [152])
                    (reg:DI 134 [ _1 ])
                    (const_int 2 [0x2])
                    (const_int 0 [0]) repeated x2
                    (reg:SI 66 vl)
                    (reg:SI 67 vtype)
                ] UNSPEC_VPREDICATE)
            (minus:RVVM8HI (reg:RVVM8HI 374 [orig:145 _12 ] [145])
                (reg:RVVM8HI 287 [orig:143 _10 ] [143]))
            (reg:RVVM8HI 284)))
"/home/abuild/rpmbuild/BUILD/highway-1.2.0/hwy/tests/if_test.cc":251:19 discrim
1 4899 {pred_subrvvm8hi}
     (expr_list:REG_DEAD (reg:RVVM8HI 374 [orig:145 _12 ] [145])
        (expr_list:REG_DEAD (reg:RVVM8HI 287 [orig:143 _10 ] [143])
            (expr_list:REG_DEAD (reg:RVVMF2BI 285 [orig:152 _19 ] [152])
                (nil)))))
during RTL pass: reload
/home/abuild/rpmbuild/BUILD/highway-1.2.0/hwy/tests/if_test.cc:268:3: internal
compiler error: in lra_split_hard_reg_for, at lra-assigns.cc:1868

Only happens with -fno-exceptions.

[Bug target/115458] [15 regression] [RISC-V] ICE in lra_split_hard_reg_for, at lra-assigns.cc:1868 unable to find a register to spill

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115458

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |15.0

[Bug target/115458] [15 regression] [RISC-V] ICE in lra_split_hard_reg_for, at lra-assigns.cc:1868 unable to find a register to spill

[pan2.li at intel dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115458

Li Pan <pan2.li at intel dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pan2.li at intel dot com

--- Comment #1 from Li Pan <pan2.li at intel dot com> ---
Ack, reproduced from today's upstream.

[Bug target/115458] [15 regression] [RISC-V] ICE in lra_split_hard_reg_for, at lra-assigns.cc:1868 unable to find a register to spill

[pan2.li at intel dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115458

--- Comment #2 from Li Pan <pan2.li at intel dot com> ---
3700bd68d1b01f0fe6d15f8a40b7fdca0904d5aa round May 15 is OK, let me run a
bisect for the first bad commit.

[Bug target/115458] [15 regression] [RISC-V] ICE in lra_split_hard_reg_for, at lra-assigns.cc:1868 unable to find a register to spill

[pan2.li at intel dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115458

--- Comment #3 from Li Pan <pan2.li at intel dot com> ---
Locate the first commit 99b1daae18c095d6c94d32efb77442838e11cbfb.

tree-optimization/114589 - remove profile based sink heuristics

[Bug target/115458] [15 regression] [RISC-V] ICE in lra_split_hard_reg_for, at lra-assigns.cc:1868 unable to find a register to spill since r15-518-g99b1daae18c095

[sjames at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115458

Sam James <sjames at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2024-06-14
            Summary|[15 regression] [RISC-V]    |[15 regression] [RISC-V]
                   |ICE in                      |ICE in
                   |lra_split_hard_reg_for, at  |lra_split_hard_reg_for, at
                   |lra-assigns.cc:1868 unable  |lra-assigns.cc:1868 unable
                   |to find a register to spill |to find a register to spill
                   |                            |since
                   |                            |r15-518-g99b1daae18c095

[Bug target/115458] [15 regression] [RISC-V] ICE in lra_split_hard_reg_for, at lra-assigns.cc:1868 unable to find a register to spill since r15-518-g99b1daae18c095

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115458

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |ice-on-valid-code

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
The bisected rev only exposes this.

[Bug target/115458] [15 regression] [RISC-V] ICE in lra_split_hard_reg_for, at lra-assigns.cc:1868 unable to find a register to spill since r15-518-g99b1daae18c095

[pan2.li at intel dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115458

--- Comment #5 from Li Pan <pan2.li at intel dot com> ---
(In reply to Richard Biener from comment #4)
> The bisected rev only exposes this.

Thanks Richard for hint, will take a look into it.