Sergei Trofimovich authored 4 years ago and Marge Bot committed 4 years ago

Before this change make-based `BIGNUM_BACKEND=native` build was failing as:

```
x86_64-pc-linux-gnu-gcc: error: libraries/ghc-bignum/gmp/objs/*.o: No such file or directory
```

This happens because ghc.mk was pulling in gmp-dependent
ghc-bignum library unconditionally. The change avoid building
ghc-bignum.

Bug: #18437


Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>

Oleg Grenrus authored 4 years ago and Marge Bot committed 4 years ago

Spotted by `vilpan` on `#haskell`

Peter Trommler authored 4 years ago and Marge Bot committed 4 years ago

Fixes #18505

Sylvain Henry authored 4 years ago and Marge Bot committed 4 years ago

shiftR/shiftL support negative arguments despite Haskell 2010 report
saying otherwise. We explicitly test for negative values which is bad
(it gets in the way of constant folding, etc.). Anyway, for consistency
we fix Bits instancesof Integer/Natural.

Simon Peyton Jones authored 4 years ago and Marge Bot committed 4 years ago

Specifically:
  #13253 exponential inlining
  #10421 ditto
  #18140 strict constructors
  #18282 another nested-function call case

This patch makes one really significant changes: change the way that
mkDupableCont handles StrictArg.  The details are explained in
GHC.Core.Opt.Simplify Note [Duplicating StrictArg].

Specific changes

* In mkDupableCont, when making auxiliary bindings for the other arguments
  of a call, add extra plumbing so that we don't forget the demand on them.
  Otherwise we haev to wait for another round of strictness analysis. But
  actually all the info is to hand.  This change affects:
  - Make the strictness list in ArgInfo be [Demand] instead of [Bool],
    and rename it to ai_dmds.
  - Add as_dmd to ValArg
  - Simplify.makeTrivial takes a Demand
  - mkDupableContWithDmds takes a [Demand]

There are a number of other small changes

1. For Ids that are used at most once in each branch of a case, make
   the occurrence analyser record the total number of syntactic
   occurrences.  Previously we recorded just OneBranch or
   MultipleBranches.

   I thought this was going to be useful, but I ended up barely
   using it; see Note [Note [Suppress exponential blowup] in
   GHC.Core.Opt.Simplify.Utils

   Actual changes:
     * See the occ_n_br field of OneOcc.
     * postInlineUnconditionally

2. I found a small perf buglet in SetLevels; see the new
   function GHC.Core.Opt.SetLevels.hasFreeJoin

3. Remove the sc_cci field of StrictArg.  I found I could get
   its information from the sc_fun field instead.  Less to get
   wrong!

4. In ArgInfo, arrange that ai_dmds and ai_discs have a simpler
   invariant: they line up with the value arguments beyond ai_args
   This allowed a bit of nice refactoring; see isStrictArgInfo,
   lazyArgcontext, strictArgContext

There is virtually no difference in nofib. (The runtime numbers
are bogus -- I tried a few manually.)

        Program           Size    Allocs   Runtime   Elapsed  TotalMem
--------------------------------------------------------------------------------
            fft          +0.0%     -2.0%    -48.3%    -49.4%      0.0%
     multiplier          +0.0%     -2.2%    -50.3%    -50.9%      0.0%
--------------------------------------------------------------------------------
            Min          -0.4%     -2.2%    -59.2%    -60.4%      0.0%
            Max          +0.0%     +0.1%     +3.3%     +4.9%      0.0%
 Geometric Mean          +0.0%     -0.0%    -33.2%    -34.3%     -0.0%

Test T18282 is an existing example of these deeply-nested strict calls.
We get a big decrease in compile time (-85%) because so much less
inlining takes place.

Metric Decrease:
    T18282

Ben Gamari authored 4 years ago and Marge Bot committed 4 years ago

Hopefully this will make the Windows jobs a bit more reliable.

Ben Gamari authored 4 years ago and Marge Bot committed 4 years ago

Previously the Hadrian jobs had the default dependencies, meaning that
they would download artifacts from all jobs of earlier stages. This is
unneccessary.

Simon Peyton Jones authored 4 years ago and Marge Bot committed 4 years ago

This patch eta-expands the Simplifier's monad, using the method
explained in GHC.Core.Unify Note [The one-shot state monad trick].
It's part of the exta-expansion programme in #18202.

It's a tiny patch, but is worth a 1-2% reduction in bytes-allocated
by the compiler.  Here's the list, based on the compiler-performance
tests in perf/compiler:

                    Reduction in bytes allocated
   T10858(normal)      -0.7%
   T12425(optasm)      -1.3%
   T13056(optasm)      -1.8%
   T14683(normal)      -1.1%
   T15164(normal)      -1.3%
   T15630(normal)      -1.4%
   T17516(normal)      -2.3%
   T18282(normal)      -1.6%
   T18304(normal)      -0.8%
   T1969(normal)       -0.6%
   T4801(normal)       -0.8%
   T5321FD(normal)     -0.7%
   T5321Fun(normal)    -0.5%
   T5642(normal)       -0.9%
   T6048(optasm)       -1.1%
   T9020(optasm)       -2.7%
   T9233(normal)       -0.7%
   T9675(optasm)       -0.5%
   T9961(normal)       -2.9%
   WWRec(normal)       -1.2%

Metric Decrease:
    T12425
    T9020
    T9961

Michalis Pardalos authored 4 years ago and Marge Bot committed 4 years ago

ALLOC_PRIM_P fails for large closures, by directly using allocate
we can handle closures which are larger than the block size.

Fixes #12492

Ben Gamari authored 4 years ago and Marge Bot committed 4 years ago

As noted in #18487, we have reached the end of this road.