[Bug c/93719] New: Unable to find a register to spill

[etchedpixels at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93719

            Bug ID: 93719
           Summary: Unable to find a register to spill
           Product: gcc
           Version: 9.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: etchedpixels at gmail dot com
  Target Milestone: ---

Created attachment 47831
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=47831&action=edit
pdp11-aout-gcc -E  capture of the problem file

pdp11-aout-gcc -fno-strict-aliasing -fomit-frame-pointer -fno-builtin
-msoft-float -Wall -Os -I../../../Library/include
-I../../../Library/include/pdp11   -c -o ac.o ac.c
ac.c: In function ‘logout’:
ac.c:214:1: error: unable to find a register to spill in class ‘GENERAL_REGS’
  214 | }
      | ^
ac.c:214:1: error: this is the insn:
(insn 60 59 61 16 (set (mem:DI (plus:HI (reg/v/f:HI 23 [ terminals.15_1 ])
                (const_int 40 [0x28])) [1 tp_43->t_time+0 S8 A16])
        (minus:DI (reg:DI 29 [ iftmp.16_11 ])
            (mem:DI (plus:HI (reg/v/f:HI 23 [ terminals.15_1 ])
                    (const_int 40 [0x28])) [1 tp_43->t_time+0 S8 A16])))
"ac.c":207:8 77 {subdi3}
     (expr_list:REG_DEAD (reg:DI 29 [ iftmp.16_11 ])
        (nil)))
ac.c:214: confused by earlier errors, bailing out



gcc -S of source attached