[Bug target/70327] New: ICE: in extract_insn, at recog.c:2287 (unrecognizable insn) with -mavx512ifma and v4ti argument

[zsojka at seznam dot cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70327

            Bug ID: 70327
           Summary: ICE: in extract_insn, at recog.c:2287 (unrecognizable
                    insn) with -mavx512ifma and v4ti argument
           Product: gcc
           Version: 6.0
            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: ---
            Target: x86_64-pc-linux-gnu

Created attachment 38040
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=38040&action=edit
reduced testcase

Compiler output:
$ gcc -mavx512ifma testcase.c         
testcase.c: In function 'foo':
testcase.c:7:1: error: unrecognizable insn:
 }
 ^
(insn 5 2 6 2 (set (mem:XI (pre_dec:DI (reg/f:DI 7 sp)) [1  S64 A512])
        (mem/c:XI (reg/f:DI 81 virtual-incoming-args) [1 v+0 S64 A512]))
testcase.c:6 -1
     (expr_list:REG_ARGS_SIZE (const_int 64 [0x40])
        (nil)))
testcase.c:7:1: internal compiler error: in extract_insn, at recog.c:2287
0xb370f8 _fatal_insn(char const*, rtx_def const*, char const*, int, char
const*)
        /repo/gcc-trunk/gcc/rtl-error.c:108
0xb3718d _fatal_insn_not_found(rtx_def const*, char const*, int, char const*)
        /repo/gcc-trunk/gcc/rtl-error.c:116
0xaeb813 extract_insn(rtx_insn*)
        /repo/gcc-trunk/gcc/recog.c:2287
0x8a65eb instantiate_virtual_regs_in_insn
        /repo/gcc-trunk/gcc/function.c:1582
0x8a65eb instantiate_virtual_regs
        /repo/gcc-trunk/gcc/function.c:1950
0x8a65eb execute
        /repo/gcc-trunk/gcc/function.c:1999
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.

$ gcc -v                     
Using built-in specs.
COLLECT_GCC=/repo/gcc-trunk/binary-latest/bin/x86_64-pc-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-234350-checking-yes-rtl-df-nographite/bin/../libexec/gcc/x86_64-pc-linux-gnu/6.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /repo/gcc-trunk//configure --enable-languages=c,c++
--enable-checking=yes,rtl,df --without-cloog --without-ppl --without-isl
--disable-libstdcxx-pch
--prefix=/repo/gcc-trunk//binary-trunk-234350-checking-yes-rtl-df-nographite
Thread model: posix
gcc version 6.0.0 20160319 (experimental) (GCC) 

Tested revisions:
trunk r234350 - FAIL
5-branch r234210 - FAIL
4_9-branch r234243 - -mavx512ifma is not recognised