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Haifa scheduler bug in egcs 1.0.2

To: linux@cthulhu.engr.sgi.com, linux-mips@fnet.fr, linux-mips@vger.rutgers.edu
Subject: Haifa scheduler bug in egcs 1.0.2
From: ralf@uni-koblenz.de
Date: Wed, 21 Oct 1998 01:50:47 +0200
Sender: owner-linux@cthulhu.engr.sgi.com
Hi all,

I've resolved a bug report of Ulf Carlson whose kernel compiles resulted
died with:

gcc -D__KERNEL__ -I/home/ulfc/kernels/sgi-lin/linux/include -Wall \
-Wstrict-prototypes -O2 -fomit-frame-pointer -G 0 -mno-abicalls -fno-pic \
-mcpu=r4600 -mips2 -pipe    arch/mips/mm/r6000.c   -o arch/mips/mm/r6000

{standard input}: Assembler messages:
{standard input}:385: Warning: Unmatched %hi reloc
{standard input}:488: Internal error!
Assertion failure in tc_gen_reloc at ./config/tc-mips.c line 10203.
Please report this bug.
make: *** [arch/mips/mm/r6000] Error 1

This is caused by bad assembler code like:

[...]
        lui     $11,%hi(r6000_flush_cache_mm) # high
        lui     $12,%hi(r6000_flush_cache_range) # high
        lui     $17,%hi(r6000_flush_tlb_all) # high
        lui     $2,%hi(r6000_flush_tlb_mm) # high
        lui     $3,%hi(r6000_flush_tlb_range) # high
        lui     $4,%hi(r6000_flush_tlb_page) # high
        lui     $5,%hi(r6000_load_pgd) # high
        lui     $6,%hi(r6000_pgd_init) # high
        lui     $7,%hi(r6000_update_mmu_cache) # high
        lui     $8,%hi(r6000_show_regs) # high
        lui     $9,%hi(r6000_add_wired_entry) # high
        lui     $10,%hi(r6000_user_mode) # high
[...]

Relocating the code generated from this source later on will not be
possible for ld.  As knows this and dies ungracefully.

I was able to track this down to the Haifa scheduler which seems to be
incompatible with the -msplit-addresses used for kernel compiles.  For
now I suggest to recompile egcs without the Haifa scheduler.  Egcs by
default doesn't enable the Haifa scheduler and there is a reason why.

This egcs 1.0.2 bug is a platform independent bug.  Since currently
egcs does not support -msplit-addresses for PIC code, that is all userland
this bug will only hit some low level stuff.

Alex or somebody else, could you make an update to the egcs package
with the haifa scheduler disabled?  Thanks!

  Ralf

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