small tidyup for printing bindings with long identifiers: allow the
binder and its definition to go on separate lines

Small performance improvement to STM: reduce the size of an atomically
frame from 3 words to 2 words by combining the "waiting" boolean field
with the info pointer, i.e. having two separate info tables/return
addresses for an atomically frame, one for the normal case and one for
the waiitng case.

small fix to debugging output

Dont try to output code for "naughty" record selectors

Document record syntax for GADTs and existentials (thanks Autrijus)

Patch from Atrijus alleged to fix FreeBSD build

We must empty the suspended_ccalling_tasks and the returning_task list
when forking.

Modify some assertions that were occasionally incorrect

remove a misplaced RELEASE_LOCK

oops, undo previous (SMP.h is already included)

#include SMP.h

define wb() and xchg() for non-SMP versions of the RTS

-ddump-minimal-imports shouldn't turn off recompilation checking

sort packages by name and version in the 'ghc-pkg list' output

fix comment

object files don't use the .obj suffix on Windows.

In SMP mode it is still possible for an update frame on the stack to
point to an indirection, when two threads evaluate the same thunk (see
comment for details).

So we use the following trick: when the GC discovers an update frame
pointing to an indirection, it changes the indirection to be an
IND_PERM, so it will be retained rather than discarded.

fix some (thankfully harmless) typos

strictly speaking, we also need write barriers in the update code too
(although gcc hasn't been caught doing any reordering here, as yet).

unlockClosure() requires a write barrier for the compiler - write
barriers aren't required for the CPU, but gcc re-orders non-aliasing
writes unless we use an explicit barrier.

This only just showed up when we started compiling the RTS with -O2.

make this compile non-threaded again

lock down the global state in the StablePtr implementation

wibble

bugfix to rev. 1.3: we must fill the slop before writing the
indirectee, because in the case of AP_STACK the indirectee will
overwrite the size field of the closure.

bugfix to new raiseAsync_

A patch to the already-somewhat-delicate machinery that deals with
pattern-matching on unboxed tuples.  This patch deals with pattern
matches that can fail, e.g.
	case f x of
	  (# Just x, Nothing #) -> ...

The fix is in desugaring of HsCase (DsExpr.lhs).

The test is dsrun013

un-revert rev. 1.22, it wasn't the cause of last weekend's breakage

report the correct version number in the "compiled by GHC version.."
message in a bootstrapped compiler.

fix up the GhcWithNativeCodeGen logic

Add "Why doesn't GHC have a .NET back end?"

make --mk-dll work with --make

Submitted by: Esa Ilari Vuokko <eivuokko@gmail.com>, thanks!

Files missed from STM implementation changes

Re-use temporary storage in the STM implementation

Wibble to typerep (fixes crash I hope)

fix repType after changes to the representation of type synonyms.
This caused the stage2 compiler to crash, because various info tables
misrepresented the pointerhood of constructor arguments.

something has gone wrong; I don't have time right now to find out
exactly what, so revert rev. 1.22 in an attempt to fix it.

fix threaded build

Two improvements to the SMP runtime:

  - support for 'par', aka sparks.  Load balancing is very primitive
    right now, but I have seen programs that go faster using par.

  - support for backing off when a thread is found to be duplicating
    a computation currently underway in another thread.  This also
    fixes some instability in SMP, because it turned out that when
    an update frame points to an indirection, which can happen if
    a thunk is under evaluation in multiple threads, then after GC
    has shorted out the indirection the update will trash the value.
    Now we suspend the duplicate computation to the heap before this
    can happen.

Additionally:

  - stack squeezing is separate from lazy blackholing, and now only
    happens if there's a reasonable amount of squeezing to be done
    in relation to the number of words of stack that have to be moved.
    This means we won't try to shift 10Mb of stack just to save 2
    words at the bottom (it probably never happened, but still).

  - update frames are now marked when they have been visited by lazy
    blackholing, as per the SMP paper.

  - cleaned up raiseAsync() a bit.

cosmetic

Add wcStore(), a write-combining store if supported

(I tried using it in the update code and only succeeded in making
things slower, but it might come in handy in the future)