Re: failuer to build uberbaum --target=m68k-elf

[Peter Barada <pbarada at mail dot wm dot sps dot mot dot com>]

>On Fri, 20 Dec 2002, Peter Barada wrote:
>> /home/peter/work/cvs-gnu/obj/gcc/xgcc -B/home/peter/work/cvs-gnu/obj/gcc/ -nostdinc -B/home/peter/work/cvs-gnu/obj/m68k-elf/m68000/newlib/ -isystem /home/peter/work/cvs-gnu/obj/m68k-elf/m68000/newlib/targ-include -isystem /home/peter/work/cvs-gnu/uberbaum/newlib/libc/include -B/home/mylocal/uberbaum/m68k-elf/m68k-elf/bin/ -B/home/mylocal/uberbaum/m68k-elf/m68k-elf/lib/ -isystem /home/mylocal/uberbaum/m68k-elf/m68k-elf/include -L/home/peter/work/cvs-gnu/obj/ld  -m68000 -DPACKAGE=\"newlib\" -DVERSION=\"1.10.0\"  -I. -I/home/peter/work/cvs-gnu/uberbaum/newlib/libm/math  -I/home/peter/work/cvs-gnu/uberbaum/newlib/libm/math/../common -O2 -DCOMPACT_CTYPE -DMISSING_SYSCALL_NAMES -fno-builtin      -O2 -g -O2  -m68000 -c /home/peter/work/cvs-gnu/uberbaum/newlib/libm/math/kf_cos.c
>> /home/peter/work/cvs-gnu/uberbaum/newlib/libm/math/kf_cos.c: In function `__kernel_cosf':
>> /home/peter/work/cvs-gnu/uberbaum/newlib/libm/math/kf_cos.c:59: internal compiler error: in trunc_int_for_mode, at explow.c:56
>
>> 2) Has *anyone* else seen this?
>
>Also spotted on the 3.3 branch, LAST_UPDATED Tue Dec 17 17:49:08
>GMT 2002
>
>> 3) Any suggestions where I should look from here?
>
>Besides running cc1 in gdb and finding out where the offending
>trunc_int_for_mode call comes from? ;-)

Ok, you asked, here's the scoop. try_combine() is called with:

Breakpoint 5, try_combine (i3=0x400bc9a0, i2=0x400bc91c, i1=0x400bc630, 
    new_direct_jump_p=0xbfffef98)
    at /home/pbarada/work/cvs-gnu/uberbaum/gcc/combine.c:1536
(gdb) call debug_rtx(i3)
(insn 22 21 23 0 0x400bc554 (set (cc0)
        (compare (reg/v:SI 37 [ ix ])
            (const_int 838860799 [0x31ffffff]))) 11 {*m68k.md:518} (insn_list 20 (nil))
    (nil))

(gdb) call debug_rtx(i2)
(insn 20 19 21 0 0x400bc554 (set (reg/v:SI 37 [ ix ])
        (and:SI (subreg:SI (reg/v:SF 30 [ x ]) 0)
            (const_int 2147483647 [0x7fffffff]))) 177 {andsi3_internal} (insn_list 3 (nil))
    (nil))

(gdb) call debug_rtx(i1)
(insn 3 267 4 0 (nil) (set (reg/v:SF 30 [ x ])
        (mem/f:SF (plus:SI (reg/f:SI 14 %a6)
                (const_int 8 [0x8])) [2 x+0 S4 A16])) 40 {*m68k.md:1097} (nil)
    (expr_list:REG_EQUIV (mem/f:SF (plus:SI (reg/f:SI 14 %a6)
                (const_int 8 [0x8])) [2 x+0 S4 A16])
        (nil)))

And try_combine puts together:

(gdb) call debug_rtx(x)
(and:SF (mem/f:SF (plus:SI (reg/f:SI 14 %a6)
            (const_int 8 [0x8])) [2 x+0 S4 A16])
    (const_int 2147483647 [0x7fffffff]))

which os passed on to simplify_logical. The callback at the abort is:

(gdb) where
#0  fancy_abort (file=0x8283d80 "/home/pbarada/work/cvs-gnu/uberbaum/gcc/explow.c", 
    line=56, function=0x8283c90 "trunc_int_for_mode")
    at /home/pbarada/work/cvs-gnu/uberbaum/gcc/diagnostic.c:1364
#1  0x080f8d8a in trunc_int_for_mode (c=2147483647, mode=SFmode)
    at /home/pbarada/work/cvs-gnu/uberbaum/gcc/explow.c:56
#2  0x08228546 in simplify_and_const_int (x=0x400ded74, mode=SFmode, varop=0x40021e34, 
    constop=2147483647) at /home/pbarada/work/cvs-gnu/uberbaum/gcc/combine.c:8088
#3  0x082246de in simplify_logical (x=0x400ded74, last=0)
    at /home/pbarada/work/cvs-gnu/uberbaum/gcc/combine.c:5418
#4  0x08223004 in combine_simplify_rtx (x=0x400ded74, op0_mode=VOIDmode, last=0, 
    in_dest=0) at /home/pbarada/work/cvs-gnu/uberbaum/gcc/combine.c:4597
#5  0x08221913 in subst (x=0x400ded74, from=0x4001ffa0, to=0x40021e34, in_dest=0, 
    unique_copy=0) at /home/pbarada/work/cvs-gnu/uberbaum/gcc/combine.c:3575
#6  0x08221804 in subst (x=0x400ded80, from=0x4001ffa0, to=0x40021e34, in_dest=0, 
    unique_copy=0) at /home/pbarada/work/cvs-gnu/uberbaum/gcc/combine.c:3526
#7  0x08221804 in subst (x=0x40021ed0, from=0x4001ffa0, to=0x40021e34, in_dest=0, 
    unique_copy=0) at /home/pbarada/work/cvs-gnu/uberbaum/gcc/combine.c:3526
#8  0x08221804 in subst (x=0x40021edc, from=0x4001ffa0, to=0x40021e34, in_dest=0, 
    unique_copy=0) at /home/pbarada/work/cvs-gnu/uberbaum/gcc/combine.c:3526
#9  0x0821ed1e in try_combine (i3=0x400bc9a0, i2=0x400bc91c, i1=0x400bc630, 
    new_direct_jump_p=0xbfffef98)
    at /home/pbarada/work/cvs-gnu/uberbaum/gcc/combine.c:1987

So trunc_int_mode() is called from simplify_and_const_int() since the
RTL is an AND(with a constant arg), but with SFmode which causes
trunc_int_mode() to barf.

At the start of simplify_logical(), I added:

  /* Can only simplify integer modes  */
  if (!(GET_MODE_CLASS (mode) == MODE_INT || GET_MODE_CLASS (mode) == MODE_PARTIAL_INT))
    return x;

Which forces simplify_logical() to abandon any simplification if the
mode of the expression is not an integer.  With this change I was able
to bootstrap gcc-3.2.1 for i686, and using that bootstrapped compiler,
build a --target-m68k-elf toolchain.  I've also built an m68k-elf
compiler from the uberbaum tree.


-- 
Peter Barada                                   Peter.Barada@motorola.com
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