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Re: bootstrap failed during 'make check'
Joern RENNECKE writes:
> Joern Rennecke wrote:
>
> > Eric Botcazou wrote:
> >
> >>> make[3]: Leaving directory `/mnt/scratch/nightly/2006-07-04/i686'
> >>> Comparing stages 2 and 3
> >>> warning: ./cc1-checksum.o differs
> >>> warning: ./cc1plus-checksum.o differs
> >>> warning: ./cc1obj-checksum.o differs
> >>> Bootstrap comparison failure!
> >>>
> >>
> >>
> >> Does the attached patch make any difference?
> >>
> >>
> > No, I still get the same set of .o files that differ, and the
> > -fdump-noaddr
> > (See PR other/28251) peephole2 dump for cfg.c compiled with stage1 /
> > stage2 cc1
> > is still the same.
>
> Hmm, as far as I can tell, stage1 i386.c:ix86_split_ashr has been
> miscompiled by gcc (GCC) 3.2.3 20030502 (Red Hat Linux 3.2.3-54).
>
> config/i386/i386.c" lines 12307 .. 12309 are:
> emit_insn ((mode == DImode
> ? gen_x86_shrd_1
> : gen_x86_64_shrd) (low[0], high[0], GEN_INT
> (count)));
> and this has been compiled as:
>
> 0x088af608 <ix86_split_ashr+486>: sub $0xc,%esp
> 0x088af60b <ix86_split_ashr+489>: sub $0xc,%esp
> 0x088af60e <ix86_split_ashr+492>: pushl 0xffffffec(%ebp)
> 0x088af611 <ix86_split_ashr+495>: push $0x0
> 0x088af613 <ix86_split_ashr+497>: call 0x8468f42 <gen_rtx_CONST_INT>
> 0x088af618 <ix86_split_ashr+502>: add $0x14,%esp
> 0x088af61b <ix86_split_ashr+505>: mov $0x88969da,%edx /*
> gen_x86_64_shrd */
> 0x088af620 <ix86_split_ashr+510>: sub $0x8,%esp
> 0x088af623 <ix86_split_ashr+513>: push %eax
> 0x088af624 <ix86_split_ashr+514>: pushl 0xfffffff0(%ebp)
> 0x088af627 <ix86_split_ashr+517>: pushl 0xfffffff8(%ebp)
> 0x088af62a <ix86_split_ashr+520>: call *%edx
> 0x088af62c <ix86_split_ashr+522>: add $0x14,%esp
> 0x088af62f <ix86_split_ashr+525>: push %eax
> 0x088af630 <ix86_split_ashr+526>: call 0x84710dd <emit_insn>
> 0x088af635 <ix86_split_ashr+531>: add $0x10,%esp
>
> I.e. we are always calling gen_x86_64_shrd no matter what the value of
> mode is.
> stepping in gdb also shows that we end up in gen_x86_64_shrd in the
> stage1 compiler,
> but in gen_x86_shrd_1 in the stage2 compiler (mode is DImode).
>
> So it seems I have to abandom the system compiler for doing bootstraps.
Can you make a simple testcase for this?
Andrew.