Created attachment 38710 [details]
reduced testcase

Compiler output:
$ x86_64-pc-linux-gnu-gcc -O -mtune=sandybridge -mavx512bw testcase.c
(nothing)

The cc1 process is slowly eating memory.

Backtrace:
(gdb) bt
#0  bitmap_set_bit (head=head@entry=0x7fffffffcfc0, bit=1153) at /repo/gcc-trunk/gcc/bitmap.c:602
#1  0x0000000000a346f7 in assign_spill_hard_regs (n=1, pseudo_regnos=0x25f7260) at /repo/gcc-trunk/gcc/lra-spills.c:275
#2  lra_spill () at /repo/gcc-trunk/gcc/lra-spills.c:587
#3  0x0000000000a0b2ad in lra (f=<optimized out>) at /repo/gcc-trunk/gcc/lra.c:2380
#4  0x00000000009b24ba in do_reload () at /repo/gcc-trunk/gcc/ira.c:5384
#5  (anonymous namespace)::pass_reload::execute (this=<optimized out>) at /repo/gcc-trunk/gcc/ira.c:5568
#6  0x0000000000ab8447 in execute_one_pass (pass=pass@entry=0x228db00) at /repo/gcc-trunk/gcc/passes.c:2344
#7  0x0000000000ab8a18 in execute_pass_list_1 (pass=0x228db00) at /repo/gcc-trunk/gcc/passes.c:2428
#8  0x0000000000ab8a2a in execute_pass_list_1 (pass=0x228ca80) at /repo/gcc-trunk/gcc/passes.c:2429
#9  0x0000000000ab8a75 in execute_pass_list (fn=<optimized out>, pass=<optimized out>) at /repo/gcc-trunk/gcc/passes.c:2439
#10 0x000000000076a554 in cgraph_node::expand (this=this@entry=0x7ffff6e4c000) at /repo/gcc-trunk/gcc/cgraphunit.c:1983
#11 0x000000000076beaf in expand_all_functions () at /repo/gcc-trunk/gcc/cgraphunit.c:2119
#12 symbol_table::compile (this=this@entry=0x7ffff6c580a8) at /repo/gcc-trunk/gcc/cgraphunit.c:2475
#13 0x000000000076e18a in symbol_table::compile (this=0x7ffff6c580a8) at /repo/gcc-trunk/gcc/cgraphunit.c:2568
#14 symbol_table::finalize_compilation_unit (this=0x7ffff6c580a8) at /repo/gcc-trunk/gcc/cgraphunit.c:2565
#15 0x0000000000bc1fcb in compile_file () at /repo/gcc-trunk/gcc/toplev.c:490
#16 0x00000000005c92fa in do_compile () at /repo/gcc-trunk/gcc/toplev.c:1998
#17 toplev::main (this=this@entry=0x7fffffffd2e0, argc=<optimized out>, argc@entry=16, argv=<optimized out>, argv@entry=0x7fffffffd3e8) at /repo/gcc-trunk/gcc/toplev.c:2127
#18 0x00000000005cb2b7 in main (argc=16, argv=0x7fffffffd3e8) at /repo/gcc-trunk/gcc/main.c:39