[Bug rtl-optimization/81284] New: [8 Regression] Bootstrap failure for 32-bit powerpc targets

["asolokha at gmx dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81284

            Bug ID: 81284
           Summary: [8 Regression] Bootstrap failure for 32-bit powerpc
                    targets
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Keywords: build, ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: rtl-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: asolokha at gmx dot com
  Target Milestone: ---
            Target: powerpc-*-linux-gnu*

gcc-8.0.0_alpha20170702 snapshot fails to bootstrap for 32-bit powerpc targets:

/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-8.0.0_alpha20170702/work/build/./gcc/xgcc
-B/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-8.0.0_alpha20170702/work/build/./gcc/
-B/usr/powerpc-e300c3-linux-gnu/bin/ -B/usr/powerpc-e300c3-linux-gnu/lib/
-isystem /usr/powerpc-e300c3-linux-gnu/include -isystem
/usr/powerpc-e300c3-linux-gnu/sys-include    -g -O2 -O2  -g -O2 -DIN_GCC 
-DCROSS_DIRECTORY_STRUCTURE  -W -Wall -Wno-narrowing -Wwrite-strings
-Wcast-qual -Wstrict-prototypes -Wmissing-prototypes -Wold-style-definition 
-isystem ./include   -fPIC -mlong-double-128 -mno-minimal-toc -g -DIN_LIBGCC2
-fbuilding-libgcc -fno-stack-protector   -fPIC -mlong-double-128
-mno-minimal-toc -I. -I. -I../.././gcc
-I/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-8.0.0_alpha20170702/work/gcc-8-20170702/libgcc
-I/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-8.0.0_alpha20170702/work/gcc-8-20170702/libgcc/.
-I/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-8.0.0_alpha20170702/work/gcc-8-20170702/libgcc/../gcc
-I/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-8.0.0_alpha20170702/work/gcc-8-20170702/libgcc/../include
-I/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-8.0.0_alpha20170702/work/gcc-8-20170702/libgcc/../libdecnumber/dpd
-I/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-8.0.0_alpha20170702/work/gcc-8-20170702/libgcc/../libdecnumber
-DHAVE_CC_TLS  -o _gcov.o -MT _gcov.o -MD -MP -MF _gcov.dep -DL_gcov -c
/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-8.0.0_alpha20170702/work/gcc-8-20170702/libgcc/libgcov-driver.c
/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-8.0.0_alpha20170702/work/gcc-8-20170702/libgcc/libgcov-driver.c:
In function 'gcov_do_dump':
/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-8.0.0_alpha20170702/work/gcc-8-20170702/libgcc/libgcov-driver.c:853:1:
error: verify_flow_info: REG_BR_PROB is set but cfg probability is not
 }
 ^
during RTL pass: loop2_doloop
/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-8.0.0_alpha20170702/work/gcc-8-20170702/libgcc/libgcov-driver.c:853:1:
internal compiler error: verify_flow_info failed
0x767d25 verify_flow_info()
       
/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-8.0.0_alpha20170702/work/gcc-8-20170702/gcc/cfghooks.c:259
0xb5e0b0 execute_function_todo
       
/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-8.0.0_alpha20170702/work/gcc-8-20170702/gcc/passes.c:2001
0xb5ef3b execute_todo
       
/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-8.0.0_alpha20170702/work/gcc-8-20170702/gcc/passes.c:2043

Reduced testcase:

void
b (int a)
{
  while (--a >= 0)
    {
    }
}

%
/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-8.0.0_alpha20170702/work/build/./gcc/xgcc
-B/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-8.0.0_alpha20170702/work/build/./gcc/
-O1 -w -c libgcov-driver.i
libgcov-driver.i: In function 'b':
libgcov-driver.i:7:1: error: verify_flow_info: REG_BR_PROB is set but cfg
probability is not
 }
 ^
during RTL pass: loop2_doloop
libgcov-driver.i:7:1: internal compiler error: verify_flow_info failed
0x767d25 verify_flow_info()
       
/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-8.0.0_alpha20170702/work/gcc-8-20170702/gcc/cfghooks.c:259
0xb5e0b0 execute_function_todo
       
/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-8.0.0_alpha20170702/work/gcc-8-20170702/gcc/passes.c:2001
0xb5ef3b execute_todo
       
/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-8.0.0_alpha20170702/work/gcc-8-20170702/gcc/passes.c:2043

This may be related to (or a duplicate of) PR81030.