[Bug target/85860] New: [8/9 Regression] ICE: in lra_split_hard_reg_for, at lra-assigns.c:1810: unable to find a register to spill with -flive-range-shrinkage -mbmi2

[zsojka at seznam dot cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85860

            Bug ID: 85860
           Summary: [8/9 Regression] ICE: in lra_split_hard_reg_for, at
                    lra-assigns.c:1810: unable to find a register to spill
                    with -flive-range-shrinkage -mbmi2
           Product: gcc
           Version: 9.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zsojka at seznam dot cz
  Target Milestone: ---
              Host: x86_64-pc-linux-gnu
            Target: x86_64-pc-linux-gnu

Created attachment 44157
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=44157&action=edit
reduced testcase

Compiler output:
$ x86_64-pc-linux-gnu-gcc -O2 -fno-guess-branch-probability
-flive-range-shrinkage -mbmi2 testcase.c 
testcase.c: In function 'foo':
testcase.c:20:1: error: unable to find a register to spill
 }
 ^
testcase.c:20:1: error: this is the insn:
(insn 214 65 201 3 (set (reg:DI 208)
        (reg:DI 1 dx)) "testcase.c":15 85 {*movdi_internal}
     (expr_list:REG_DEAD (reg:DI 1 dx)
        (nil)))
during RTL pass: reload
testcase.c:20:1: internal compiler error: in lra_split_hard_reg_for, at
lra-assigns.c:1810
0x67a94c _fatal_insn(char const*, rtx_def const*, char const*, int, char
const*)
        /repo/gcc-trunk/gcc/rtl-error.c:108
0xc47293 lra_split_hard_reg_for()
        /repo/gcc-trunk/gcc/lra-assigns.c:1810
0xc40ee9 lra(_IO_FILE*)
        /repo/gcc-trunk/gcc/lra.c:2507
0xbef719 do_reload
        /repo/gcc-trunk/gcc/ira.c:5465
0xbef719 execute
        /repo/gcc-trunk/gcc/ira.c:5649
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.


$ x86_64-pc-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=/repo/gcc-trunk/binary-latest-amd64/bin/x86_64-pc-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-260408-checking-yes-rtl-df-extra-amd64/bin/../libexec/gcc/x86_64-pc-linux-gnu/9.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /repo/gcc-trunk//configure --enable-languages=c,c++
--enable-valgrind-annotations --disable-nls --enable-checking=yes,rtl,df,extra
--with-cloog --with-ppl --with-isl --build=x86_64-pc-linux-gnu
--host=x86_64-pc-linux-gnu --target=x86_64-pc-linux-gnu
--with-ld=/usr/bin/x86_64-pc-linux-gnu-ld
--with-as=/usr/bin/x86_64-pc-linux-gnu-as --disable-libstdcxx-pch
--prefix=/repo/gcc-trunk//binary-trunk-260408-checking-yes-rtl-df-extra-amd64
Thread model: posix
gcc version 9.0.0 20180520 (experimental) (GCC)