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Re: C++ ptrmemfun break if FUNCTION_BOUNDARY < 2 * BITS_PER_UNIT
- To: Alexandre Oliva <aoliva at redhat dot com>
- Subject: Re: C++ ptrmemfun break if FUNCTION_BOUNDARY < 2 * BITS_PER_UNIT
- From: Richard Earnshaw <rearnsha at arm dot com>
- Date: Wed, 18 Apr 2001 13:47:29 +0100
- cc: Joern Rennecke <amylaar at redhat dot com>, wilson at cygnus dot com (Jim Wilson), gcc at gcc dot gnu dot org, gcc-patches at gcc dot gnu dot org, gdb at sources dot redhat dot com, Richard dot Earnshaw at arm dot com
- Organization: ARM Ltd.
- Reply-To: Richard dot Earnshaw at arm dot com
aoliva@redhat.com said:
> I don't want to extract a bit. I want to extract the remaining bits.
> The delta was shifted left (or multiplied by 2) to make room for the
> vbit; now I want the delta back. It's a signed offset.
This is OK, provided that you can guarantee that the left shift won't
cause the "sign" bit to change value. That is
((X << 1) MOD size) >> 1 == X
for all interesting values of X.
R.