[Bug rtl-optimization/68205] New: ICE compiling gcc.c-torture/execute/20040709-2.c with -fno-common on arm-none-eabi

[sandra at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68205

            Bug ID: 68205
           Summary: ICE compiling gcc.c-torture/execute/20040709-2.c with
                    -fno-common on arm-none-eabi
           Product: gcc
           Version: 5.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: rtl-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: sandra at gcc dot gnu.org
  Target Milestone: ---
            Target: arm-none-eabi
             Build: i686-pc-linux-gnu

I am seeing this failure on the GCC 5 branch, built for arm-none-eabi:

$ arm-none-eabi-gcc -S
/scratch/sandra/arm-altera-stable/src/gcc-5-2015.11/gcc/testsuite/gcc.c-torture/execute/20040709-2.c
-fno-diagnostics-show-caret -fdiagnostics-color=never    -O2  -w -fno-common
-fdump-rtl-all
/scratch/sandra/arm-altera-stable/src/gcc-5-2015.11/gcc/testsuite/gcc.c-torture/execute/20040709-2.c:
In function 'testW':
/scratch/sandra/arm-altera-stable/src/gcc-5-2015.11/gcc/testsuite/gcc.c-torture/execute/20040709-2.c:114:72:
error: insn does not satisfy its constraints:
/scratch/sandra/arm-altera-stable/src/gcc-5-2015.11/gcc/testsuite/gcc.c-torture/execute/20040709-2.c:54:10:
note: in definition of macro 'T'
(insn 389 374 387 7 (parallel [
            (set (reg:SI 2 r2 [323])
                (truncate:SI (lshiftrt:DI (mult:DI (sign_extend:DI (reg:SI 9 r9
[orig:321 D.8956 ] [321]))
                            (sign_extend:DI (reg:SI 6 r6 [324])))
                        (const_int 32 [0x20]))))
            (clobber (scratch:SI))
        ])
/scratch/sandra/arm-altera-stable/src/gcc-5-2015.11/gcc/testsuite/gcc.c-torture/execute/20040709-2.c:114
57 {*smulsi3_highpart_nov6}
     (nil))
/scratch/sandra/arm-altera-stable/src/gcc-5-2015.11/gcc/testsuite/gcc.c-torture/execute/20040709-2.c:114:72:
internal compiler error: in extract_constrain_insn, at recog.c:2246
/scratch/sandra/arm-altera-stable/src/gcc-5-2015.11/gcc/testsuite/gcc.c-torture/execute/20040709-2.c:54:10:
note: in definition of macro 'T'
0x85431b7 _fatal_insn(char const*, rtx_def const*, char const*, int, char
const*)
        /scratch/sandra/arm-eabi-5/src/gcc-5/gcc/rtl-error.c:110
0x85431f5 _fatal_insn_not_found(rtx_def const*, char const*, int, char const*)
        /scratch/sandra/arm-eabi-5/src/gcc-5/gcc/rtl-error.c:121
0x8519445 extract_constrain_insn(rtx_insn*)
        /scratch/sandra/arm-eabi-5/src/gcc-5/gcc/recog.c:2246
0x84fb55f reload_cse_simplify_operands
        /scratch/sandra/arm-eabi-5/src/gcc-5/gcc/postreload.c:430
0x84fdf12 reload_cse_simplify
        /scratch/sandra/arm-eabi-5/src/gcc-5/gcc/postreload.c:207
0x84fdf12 reload_cse_regs_1
        /scratch/sandra/arm-eabi-5/src/gcc-5/gcc/postreload.c:246
0x84fe122 reload_cse_regs
        /scratch/sandra/arm-eabi-5/src/gcc-5/gcc/postreload.c:94
0x84fe122 execute
        /scratch/sandra/arm-eabi-5/src/gcc-5/gcc/postreload.c:2387
0x84fe122 execute
        /scratch/sandra/arm-eabi-5/src/gcc-5/gcc/postreload.c:2381
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.

Same test case with same options compiles successfully on GCC 4.9 branch.

On mainline the test also compiles successfully.  I tracked down that it was
"fixed" by r224048, but that patch looks unrelated (I think it just changed the
input to reload by making different optimization decisions) so perhaps the bug
is still latent?