http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55146
Oleg Endo <olegendo at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |olegendo at gcc dot gnu.org
--- Comment #1 from Oleg Endo <olegendo at gcc dot gnu.org> 2012-12-10 09:15:15
UTC ---
(In reply to comment #0)
> Created attachment 28580 [details]
> testcase C file
>
> Switch statement with enough cases inside is translated to jumptable. If the
> offsets are small enough, byte entries are used. If there is odd number of
> cases this implies padding byte (since all SH instructions are 2 byte wide).
> In
> the corner case this padding byte can cause the offset to switch from positive
> to negative since move.b instruction used to fetch jumptable entry sign
> extends
> the byte. This bug is very old and dates back at least to 4.0.3 days. See
> attachment.
> When compiled with sh-elf-gcc -Os -c test-jens.c -o sh-test.o it produces
> wrong
> jumping code. http://pastebin.com/ZgJK3bgS has slightly commented disassembly
> to point out what I mean.
>
> The workaround is to decrease MIN_OFFSET by one for byte case in
> gcc/config/sh/sh.h . This is not a proper fix though.
Thanks for reporting this. Could you please attach the file that you had on
pastebin? The link seems dead.
