RTL check: access of elt 1 of `not' with last elt 0

[toon@moene.indiv.nluug.nl]

L.S.,

So I was just trying to bootstrap this afternoon's CVS'd tree
with --enable-checking while it fell over thusly:

_negdi2
_lshrdi3
_ashldi3
_ashrdi3
_ffsdi2
_udiv_w_sdiv
In file included from ../../egcs/gcc/libgcc2.c:163:
./../egcs/gcc/longlong.h:591: warning: macro arg `d' would be stringified with -traditional.
./../egcs/gcc/longlong.h:591: warning: macro arg `d' would be stringified with -traditional.
./../egcs/gcc/longlong.h:599: warning: macro arg `d' would be stringified with -traditional.
./../egcs/gcc/longlong.h:599: warning: macro arg `d' would be stringified with -traditional.
./../egcs/gcc/libgcc2.c: In function `__udiv_w_sdiv':
./../egcs/gcc/libgcc2.c:423: RTL check: access of elt 1 of `not' with last elt 0
./../egcs/gcc/libgcc2.c:423: Internal compiler error in `combine_simplify_rtx', at combine.c:3826
Please submit a full bug report.

This is the relevant part of combine.c:


      if (STORE_FLAG_VALUE == -1
          && XEXP (x, 1) == const1_rtx
          && GET_CODE (XEXP (x, 0)) == ASHIFTRT
          && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT
          && INTVAL (XEXP (XEXP (x, 0), 1)) == GET_MODE_BITSIZE (mode) - 1)
        return gen_rtx_combine (GE, mode, XEXP (XEXP (x, 0), 0), const0_rtx);

(the XEXP (x, 1) seems to be the culprit, according to the line number above).

Anyone knows this code well enough to have a suggestion ?

Thanks in advance,
Toon Moene.