Initial rehash of Memcheck's shadow-space management to support both
32- and 64-bit targets, little- and big-endian. It does more or less
work on x86 as-is, although is unusably slow since I have knocked out
all the fast-path cases and am concentrating on getting the baseline
functionality correct. The fast cases will go back in in due course.
The fundamental idea is to retain the old 2-level indexing for speed,
even on a 64-bit target. Since that's clearly unviable on a 64-bit
target, the primary map handles only first N gigabytes of address
space (probably to be set to 16, 32 or 64G). Addresses above that are
handled slowly using an auxiliary primary map which explicitly lists
(base, &-of-secondary-map) pairs. The goal is to have the
address-space-manager try and put everything below the 16/32/64G
boundary, so we hit the fast cases almost all the time.
Performance of the 32-bit case should be unaffected since the fast map
will always cover at least the lowest 4G of address space.
There are many word-size and endianness cleanups.
Jeremy's distinguished-map space-compression scheme is retained, in
modified form, as it is simple and seems effective at reducing
Memcheck's space use.
Note this is all subject to rapid change.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@3535 a5019735-40e9-0310-863c-91ae7b9d1cf9
3 files changed