[Bug target/56942] New: MIPS GCC will not build with -mips16 mode because libgcc fails to build

[sje at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56942

             Bug #: 56942
           Summary: MIPS GCC will not build with -mips16 mode because
                    libgcc fails to build
    Classification: Unclassified
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: sje@gcc.gnu.org
            Target: mips*-*-*


While building a MIPS GCC that includes mips16 libraries I get an assertion
from GCC.  Here is a testcase cutdown from libgcc unwind-dw2.c:


enum dwarf_call_frame_info {
  DW_CFA_set_loc = 0x01 ,
  DW_CFA_advance_loc1 = 0x02 ,
  DW_CFA_advance_loc2 = 0x03 ,
  DW_CFA_GNU_args_size = 0x2e ,
  DW_CFA_GNU_negative_offset_extended = 0x2f
};
typedef struct { void *pc; } _Unwind_FrameState;
void execute_cfa_program (const unsigned char *insn_ptr,
                          const unsigned char *insn_end,
                          _Unwind_FrameState *fs)
{
    while (insn_ptr < insn_end)     {
        unsigned char insn = *insn_ptr++;
        void *reg;
        void *utmp;
    switch (insn)  {
          case DW_CFA_set_loc:    { }
          case DW_CFA_advance_loc1:    fs->pc += foo (insn_ptr) * 4;
          case DW_CFA_advance_loc2:    fs->pc += foo (insn_ptr) * 4;
          case DW_CFA_GNU_args_size:    insn_ptr = bar (insn_ptr, &utmp);
          case DW_CFA_GNU_negative_offset_extended:    insn_ptr = bar
(insn_ptr,
 &reg);
        }
   }
}


And here is the assertion I get:

gcc/cc1 -quiet -g -mips16 -O2 -minterlink-mips16 -fPIC -g
-I/local/home/sellcey/nightly/src x.c

x.c:25:1: internal compiler error: in output_555, at config/mips/mips.md:6024

0xb8fc19 output_555
    /local/home/sellcey/nightly/src/gcc/gcc/config/mips/mips.md:6024
0x6b60e2 final_scan_insn(rtx_def*, _IO_FILE*, int, int, int*)
    /local/home/sellcey/nightly/src/gcc/gcc/final.c:2853
0x6b6c8f final(rtx_def*, _IO_FILE*, int)
    /local/home/sellcey/nightly/src/gcc/gcc/final.c:1957
0x6b6eb9 rest_of_handle_final
    /local/home/sellcey/nightly/src/gcc/gcc/final.c:4332
Please submit a full bug report,
with preprocessed source if appropriate.