[Bug target/64061] New: [5 Regression] ICE: in gen_rtx_SUBREG, at emit-rtl.c:894 with -O2 -g -fno-dce -fno-tree-dce

[zsojka at seznam dot cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64061

            Bug ID: 64061
           Summary: [5 Regression] ICE: in gen_rtx_SUBREG, at
                    emit-rtl.c:894 with -O2 -g -fno-dce -fno-tree-dce
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zsojka at seznam dot cz

Created attachment 34104
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34104&action=edit
reduced testcase

Compiler output:
$ gcc -O2 -g -fno-dce -fno-tree-dce testcase.c                            
testcase.c: In function 'foo':
testcase.c:18:1: internal compiler error: in gen_rtx_SUBREG, at emit-rtl.c:894
 }
 ^
0x8a1ef0 gen_rtx_SUBREG(machine_mode, rtx_def*, int)
        /mnt/svn/gcc-trunk/gcc/emit-rtl.c:894
0xa9b86c lra_substitute_pseudo(rtx_def**, int, rtx_def*)
        /mnt/svn/gcc-trunk/gcc/lra.c:1813
0xa9b754 lra_substitute_pseudo(rtx_def**, int, rtx_def*)
        /mnt/svn/gcc-trunk/gcc/lra.c:1827
0xa9b754 lra_substitute_pseudo(rtx_def**, int, rtx_def*)
        /mnt/svn/gcc-trunk/gcc/lra.c:1827
0xa9b992 lra_substitute_pseudo_within_insn(rtx_insn*, int, rtx_def*)
        /mnt/svn/gcc-trunk/gcc/lra.c:1846
0xabbc88 process_bb_lives
        /mnt/svn/gcc-trunk/gcc/lra-lives.c:737
0xabc2ea lra_create_live_ranges_1
        /mnt/svn/gcc-trunk/gcc/lra-lives.c:1255
0xabcbc8 lra_create_live_ranges(bool, bool)
        /mnt/svn/gcc-trunk/gcc/lra-lives.c:1329
0xa9c3a7 lra(_IO_FILE*)
        /mnt/svn/gcc-trunk/gcc/lra.c:2361
0xa4c5d1 do_reload
        /mnt/svn/gcc-trunk/gcc/ira.c:5391
0xa4c5d1 execute
        /mnt/svn/gcc-trunk/gcc/ira.c:5561
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <http://gcc.gnu.org/bugs.html> for instructions.

Tested revisions:
r217996 - ICE
4_9 r216937 - OK