Deadly optimization bug (all gcc versions!)

[David Edelsohn]

>>>>> veksler  writes:

veksler> The bug shows itself on gcc-2.7.0 gcc-2.7.2.1, egcs-1.0.1, egcs-1.1.2,
veksler> gcc-2.95.
veksler> On AIX-4.1, Linux-x86 (RH4.2 and RH6.0).

	This means that you have seen the bug in both PowerPC and IA-32
code generation?  I definitely see it in PowerPC.  A whole group of
instructions disappear between flow and combine.  Also, -O3 with inlining
seems to produce correct results.  Maybe combine is trying some alternate
instructions, failing, and then not properly restoring the instructions?

David