| Commit message (Collapse) | Author | Age | Files | Lines |
|---|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
Most of the other users of the fptools build system have migrated to
Cabal, and with the move to darcs we can now flatten the source tree
without losing history, so here goes.
The main change is that the ghc/ subdir is gone, and most of what it
contained is now at the top level. The build system now makes no
pretense at being multi-project, it is just the GHC build system.
No doubt this will break many things, and there will be a period of
instability while we fix the dependencies. A straightforward build
should work, but I haven't yet fixed binary/source distributions.
Changes to the Building Guide will follow, too.
|
| |
|
|
|
|
|
| |
Tweaks to get the GHC sources through Haddock. Doesn't quite work
yet, because Haddock complains about the recursive modules. Haddock
needs to understand SOURCE imports (it can probably just ignore them
as a first attempt).
|
| |
|
|
|
| |
Eeek! intsToReverseBitmap was borked for bitmaps with more than
wORD_SIZE_IN_BITS entries.
|
|
|
Change the way SRTs are represented:
Previously, the SRT associated with a function or thunk would be a
sub-list of the enclosing top-level function's SRT. But this approach
can lead to lots of duplication: if a CAF is referenced in several
different thunks, then it may appear several times in the SRT.
Let-no-escapes compound the problem, because the occurrence of a
let-no-escape-bound variable would expand to all the CAFs referred to
by the let-no-escape.
The new way is to describe the SRT associated with a function or thunk
as a (pointer+offset,bitmap) pair, where the pointer+offset points
into some SRT table (the enclosing function's SRT), and the bitmap
indicates which entries in this table are "live" for this closure.
The bitmap is stored in the 16 bits previously used for the length
field, but this rarely overflows. When it does overflow, we store the
bitmap externally in a new "SRT descriptor".
Now the enclosing SRT can be a set, hence eliminating the duplicates.
Also, we now have one SRT per top-level function in a recursive group,
where previously we used to have one SRT for the whole group. This
helps keep the size of SRTs down.
Bottom line: very little difference most of the time. GHC itself got
slightly smaller. One bad case of a module in GHC which had a huge
SRT has gone away.
While I was in the area:
- Several parts of the back-end require bitmaps. Functions for
creating bitmaps are now centralised in the Bitmap module.
- We were trying to be independent of word-size in a couple of
places in the back end, but we've now abandoned that strategy so I
simplified things a bit.
|
