[Bug middle-end/86640] New: [8/9 regression] ICE in combine

[ramana at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86640

            Bug ID: 86640
           Summary: [8/9 regression] ICE in combine
           Product: gcc
           Version: 8.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ramana at gcc dot gnu.org
  Target Milestone: ---

char fn1() {

  long long b[5];

  for (int a = 0; a < 5; a++)

    b[a] = ~0ULL;

  return b[3];

}


$> arm-none-linux-gnueabihf-gcc -c -O3 -mfpu=neon -mfloat-abi=hard
-march=armv7-a /tmp/crash.c 
during RTL pass: combine
/tmp/crash.c: In function ‘fn1’:
/tmp/crash.c:11:1: internal compiler error: in do_SUBST, at combine.c:731
 }
 ^
0x12e637c do_SUBST
       
/tmp/dgboter/bbs/bc-b3-3-13--rhe6x86_64/buildbot/rhe6x86_64--arm-none-linux-gnueabihf/build/src/gcc/gcc/combine.c:730
0x12f913e subst
       
/tmp/dgboter/bbs/bc-b3-3-13--rhe6x86_64/buildbot/rhe6x86_64--arm-none-linux-gnueabihf/build/src/gcc/gcc/combine.c:5589
0x12fb2d1 try_combine
       
/tmp/dgboter/bbs/bc-b3-3-13--rhe6x86_64/buildbot/rhe6x86_64--arm-none-linux-gnueabihf/build/src/gcc/gcc/combine.c:3359
0x1301398 combine_instructions
       
/tmp/dgboter/bbs/bc-b3-3-13--rhe6x86_64/buildbot/rhe6x86_64--arm-none-linux-gnueabihf/build/src/gcc/gcc/combine.c:1299
0x1301398 rest_of_handle_combine
       
/tmp/dgboter/bbs/bc-b3-3-13--rhe6x86_64/buildbot/rhe6x86_64--arm-none-linux-gnueabihf/build/src/gcc/gcc/combine.c:14898
0x1301398 execute
       
/tmp/dgboter/bbs/bc-b3-3-13--rhe6x86_64/buildbot/rhe6x86_64--arm-none-linux-gnueabihf/build/src/gcc/gcc/combine.c:14943