[Bug target/47727] [x32] internal compiler error: Segmentation fault

[hjl.tools at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47727

--- Comment #3 from H.J. Lu <hjl.tools at gmail dot com> 2011-02-14 05:18:23 UTC ---
(In reply to comment #2)
> cse1 generates:
> 
> ;; Succ edge  EXIT [100.0%]  (fallthru)
> 
> ;; Insn is not within a basic block
> (insn 63 57 64 (set (reg:SI 100)
>         (symbol_ref:SI ("__CTOR_END__") [flags 0x2]  <var_decl 0x7ffff0ced000
> __CTOR_END__>)) -1
>      (nil))
> 
> ;; Insn is not within a basic block
> (insn 64 63 65 (parallel [
>             (set (reg:SI 99) 
>                 (plus:SI (reg:SI 100)
>                     (const_int -4 [0xfffffffffffffffc])))
>             (clobber (reg:CC 17 flags))
>         ]) -1
>      (nil))
> 
> ;; Insn is not within a basic block
> (insn 65 64 0 (set (reg:DI 98)
>         (zero_extend:DI (reg:SI 99))) -1
>      (nil))
> 
> This may lead to the DF problem.

This is because cse_insn calls fold_rtx with

(gdb) call debug_rtx (x)
(zero_extend:DI (reg/f:SI 95))
(gdb) call debug_rtx (insn)
(insn 37 36 38 3 (set (reg/f:DI 94)
        (zero_extend:DI (reg/f:SI 95))) c.i:7 115 {*zero_extendsidi2_rex64}
     (nil))
(gdb)

It leads to

  switch (GET_RTX_CLASS (code))
    {    
    case RTX_UNARY:
      {    
        /* We can't simplify extension ops unless we know the
           original mode.  */
        if ((code == ZERO_EXTEND || code == SIGN_EXTEND)
            && mode_arg0 == VOIDmode)
          break;

        new_rtx = simplify_unary_operation (code, mode,
                                        const_arg0 ? const_arg0 : folded_arg0,
                                        mode_arg0);
      }                                      
      break;

Breakpoint 7, emit_insn (x=0x7ffff0d46900)
    at /export/gnu/import/git/gcc-x32/gcc/emit-rtl.c:4791
4791      rtx last = get_last_insn();
(gdb) bt
#0  emit_insn (x=0x7ffff0d46900)
    at /export/gnu/import/git/gcc-x32/gcc/emit-rtl.c:4791
#1  0x00000000006f0e87 in emit_move_insn_1 (x=0x7ffff0d42dc0, y=0x7ffff0d42b40)
    at /export/gnu/import/git/gcc-x32/gcc/expr.c:3305
#2  0x00000000006f125a in emit_move_insn (x=0x7ffff0d42dc0, y=0x7ffff0d42b40)
    at /export/gnu/import/git/gcc-x32/gcc/expr.c:3395
#3  0x00000000006d503e in copy_to_mode_reg (mode=SImode, x=0x7ffff0d42b40)
    at /export/gnu/import/git/gcc-x32/gcc/explow.c:637
#4  0x00000000008d9656 in expand_binop_directly (mode=SImode, 
    binoptab=0x1809e20, op0=0x7ffff0d42b40, op1=0x7ffff0dea430, 
    target=0x7ffff0d42da0, unsignedp=1, methods=OPTAB_LIB_WIDEN, 
    last=0x7ffff0cf1980) at /export/gnu/import/git/gcc-x32/gcc/optabs.c:1461
#5  0x00000000008d99c2 in expand_binop (mode=SImode, binoptab=0x1809e20, 
    op0=0x7ffff0d42b40, op1=0x7ffff0dea430, target=0x7ffff0d42da0, 
    unsignedp=1, methods=OPTAB_LIB_WIDEN)
    at /export/gnu/import/git/gcc-x32/gcc/optabs.c:1551
#6  0x00000000008d9185 in expand_simple_binop (mode=SImode, code=PLUS, 
    op0=0x7ffff0d42b40, op1=0x7ffff0dea430, target=0x7ffff0d42da0, 
    unsignedp=1, methods=OPTAB_LIB_WIDEN)
    at /export/gnu/import/git/gcc-x32/gcc/optabs.c:1295
#7  0x0000000000701383 in force_operand (value=0x7ffff0d473a8, 
    target=0x7ffff0d42da0) at /export/gnu/import/git/gcc-x32/gcc/expr.c:6452
#8  0x00000000006d4fed in copy_to_mode_reg (mode=SImode, x=0x7ffff0d473a8)
---Type <return> to continue, or q <return> to quit---
    at /export/gnu/import/git/gcc-x32/gcc/explow.c:633
#9  0x00000000008df8d7 in maybe_emit_unop_insn (icode=2221, 
    target=0x7ffff0d42d80, op0=0x7ffff0d473a8, code=ZERO_EXTEND)
    at /export/gnu/import/git/gcc-x32/gcc/optabs.c:3746
#10 0x00000000008dfa49 in emit_unop_insn (icode=2221, target=0x7ffff0d42d80, 
    op0=0x7ffff0d473a8, code=ZERO_EXTEND)
    at /export/gnu/import/git/gcc-x32/gcc/optabs.c:3776
#11 0x00000000006e9df4 in convert_move (to=0x7ffff0d42d80, 
    from=0x7ffff0d473a8, unsignedp=1)
    at /export/gnu/import/git/gcc-x32/gcc/expr.c:612
#12 0x00000000006ea5de in convert_modes (mode=DImode, oldmode=SImode, 
    x=0x7ffff0d473a8, unsignedp=1)
    at /export/gnu/import/git/gcc-x32/gcc/expr.c:791
#13 0x00000000006d4971 in convert_memory_address_addr_space (to_mode=DImode, 
    x=0x7ffff0d473a8, as=0 '\000')
    at /export/gnu/import/git/gcc-x32/gcc/explow.c:408
#14 0x00000000006d488d in convert_memory_address_addr_space (to_mode=DImode, 
    x=0x7ffff0d43d10, as=0 '\000')
    at /export/gnu/import/git/gcc-x32/gcc/explow.c:379
#15 0x00000000009bceb1 in simplify_unary_operation_1 (code=ZERO_EXTEND, 
    mode=DImode, op=0x7ffff0d43d10)
    at /export/gnu/import/git/gcc-x32/gcc/simplify-rtx.c:1111
#16 0x00000000009bafa8 in simplify_unary_operation (code=ZERO_EXTEND, 
---Type <return> to continue, or q <return> to quit---
    mode=DImode, op=0x7ffff0d43d10, op_mode=SImode)
    at /export/gnu/import/git/gcc-x32/gcc/simplify-rtx.c:526
#17 0x0000000001044375 in fold_rtx (x=0x7ffff0d43d20, insn=0x7ffff0d463f0)
    at /export/gnu/import/git/gcc-x32/gcc/cse.c:3350
#18 0x00000000010470f8 in cse_insn (insn=0x7ffff0d463f0)
    at /export/gnu/import/git/gcc-x32/gcc/cse.c:4501

It generates a bunch of orphaned instructions.