[Bug middle-end/84823] [6 Regression] x86 LRA hang on valid code (no ICE) with -fno-omit-frame-pointer

[awilfox at adelielinux dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84823

A. Wilcox (awilfox) <awilfox at adelielinux dot org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to fail|                            |6.4.0

--- Comment #2 from A. Wilcox (awilfox) <awilfox at adelielinux dot org> ---
We applied the fix from PR78911 (rev 246059:
https://code.foxkit.us/adelie/packages/blob/master/system/gcc/lra-pentium.patch
is what we applied).

We were running through a mass rebuild and just 52 minutes in, we've already
tripped over this bug again, compiling the test suite for nettle-3.4:

awilcox on ciall [pts/2 Sun 29 3:40] testsuite: gcc -I.. -I.. -O2 -ggdb
-march=pentium-mmx -mtune=pentium-m -fno-omit-frame-pointer -DHAVE_CONFIG_H -O2
-ggdb -march=pentium-mmx -mtune=pentium-m -fno-omit-frame-pointer -g -g -ggdb3
-Wall -W   -Wmissing-prototypes -Wmissing-declarations -Wstrict-prototypes  
-Wpointer-arith -Wbad-function-cast -Wnested-externs  -MT ecc-mul-a-test.o -MD
-MP -MF ecc-mul-a-test.o.d -c ecc-mul-a-test.c -fchecking -Q -save-temps 

Execution times (seconds)
 phase setup             :   0.00 ( 0%) usr   0.00 ( 0%) sys   0.01 (100%) wall
    549 kB (98%) ggc
 TOTAL                 :   0.00             0.00             0.01              
 558 kB
Extra diagnostic checks enabled; compiler may run slowly.
 realpath fgets fread fwrite vsnprintf vsprintf snprintf sprintf bcopy bzero
memcpy memmove memset stpcpy stpncpy strcat strcpy strncat strncpy strlcat
strlcpy __gmpz_abs __gmpz_fits_uint_p __gmpz_fits_ulong_p __gmpz_fits_ushort_p
__gmpz_get_ui __gmpz_getlimbn __gmpz_neg __gmpz_perfect_square_p
__gmpz_popcount __gmpz_set_q __gmpz_size __gmpq_abs __gmpq_neg __gmpn_add
__gmpn_add_1 __gmpn_cmp __gmpn_zero_p __gmpn_sub __gmpn_sub_1 __gmpn_neg
test_main
Analyzing compilation unit
Performing interprocedural optimizations
 <*free_lang_data> <visibility> <build_ssa_passes> <opt_local_passes>
<targetclone> <free-inline-summary> <whole-program> <profile_estimate> <icf>
<devirt> <cp> <inline> <pure-const> <static-var> <single-use>
<comdats>Assembling functions:
 <simdclone> test_main


Attaching to process 20502
Reading symbols from /usr/libexec/gcc/i586-foxkit-linux-musl/6.4.0/cc1...(no
debugging symbols found)...done.
Reading symbols from /usr/lib/libisl.so.15...(no debugging symbols
found)...done.
Reading symbols from /usr/lib/libmpc.so.3...(no debugging symbols
found)...done.
Reading symbols from /usr/lib/libmpfr.so.4...(no debugging symbols
found)...done.
Reading symbols from /usr/lib/libgmp.so.10...(no debugging symbols
found)...done.
Reading symbols from /lib/libz.so.1...(no debugging symbols found)...done.
Reading symbols from /lib/ld-musl-i386.so.1...Reading symbols from
/usr/lib/debug//lib/ld-musl-i386.so.1.debug...done.
done.
0x084faee6 in lra_assign() ()
(gdb) bt
#0  0x084faee6 in lra_assign() ()
#1  0x084f67f6 in lra(_IO_FILE*) ()
#2  0x084b1f97 in ?? ()
#3  0x08584ab4 in execute_one_pass(opt_pass*) ()
#4  0x08585068 in ?? ()
#5  0x08585078 in ?? ()
#6  0x085850da in execute_pass_list(function*, opt_pass*) ()
#7  0x082ebfe4 in cgraph_node::expand() ()
#8  0x082ed656 in ?? ()
#9  0x082ef189 in symbol_table::finalize_compilation_unit() ()
#10 0x086404fc in ?? ()
#11 0x081bd7f4 in toplev::main(int, char**) ()
#12 0x081bf8c8 in main ()