[Bug rtl-optimization/64217] New: LRA: generate wrong liveness info after r217947 for clobber in jump_insn

["npickito at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64217

            Bug ID: 64217
           Summary: LRA: generate wrong liveness info after r217947 for
                    clobber in jump_insn
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: rtl-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: npickito at gmail dot com

Created attachment 34214
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34214&action=edit
rtl dumps for r217946 and  r217947

Configure:

--target=nds32le-elf --enable-checking=yes

Testcase:
testsuite/gcc.c-torture/compile/20020116-1.c

How to reproduce:
nds32le-elf-gcc testsuite/gcc.c-torture/compile/20020116-1.c -O0

What's happen:

...
(jump_insn 17 56 18 4 (parallel [
            (set (pc)
                (mem:SI (plus:SI (mult:SI (reg:SI 45) 
                            (const_int 4 [0x4]))
                        (label_ref 18)) [0  S4 A32]))
            (use (label_ref 18))
            (clobber (reg:SI 47))
            (clobber (reg:SI 15 $ta))
        ]) testsuite/gcc.c-torture/compile/20020116-1.c:13 87 {casesi_internal}
     (expr_list:REG_DEAD (reg:SI 45) 
        (expr_list:REG_UNUSED (reg:SI 47) 
            (expr_list:REG_UNUSED (reg:SI 15 $ta)
                (nil))))
 -> 18) 
...

LRA dump in r217946:
...
 r47: [15..16]
...
Compressing live ranges: from 21 to 15 - 71% 
Ranges after the compression:
...
 r47: [11..12]
...

LRA dump in r217947:
...
 r47: [0..26]
...
Compressing live ranges: from 27 to 15 - 55% 
Ranges after the compression:
...
 r47: [0..14]
...

Full dump in attachment.



Back trace:
~/gcc-trunk/gcc/testsuite/gcc.c-torture/compile/20020116-1.c: In function
'main':
~/gcc-trunk/gcc/testsuite/gcc.c-torture/compile/20020116-1.c:28:1: internal
compiler error: in lra_assign, at lra-assigns.c:1536
 }
 ^
0xb6015d lra_assign()
    ../../src/gcc/lra-assigns.c:1536
0xb5a022 lra(_IO_FILE*)
    ../../src/gcc/lra.c:2322
0xb0ce20 do_reload
    ../../src/gcc/ira.c:5391
0xb0d1b2 execute
    ../../src/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.