[Git][ghc/ghc][wip/T21470] 10 commits: CoreToStg: purge `DynFlags`.

Fri Oct 21 09:28:13 UTC 2022

Andreas Klebinger pushed to branch wip/T21470 at Glasgow Haskell Compiler / GHC

Commits:
ff6f2228 by M Farkas-Dyck at 2022-10-20T16:15:51-04:00
CoreToStg: purge `DynFlags`.

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1ebd521f by Matthew Pickering at 2022-10-20T16:16:27-04:00
ci: Make fat014 test robust

For some reason I implemented this as a makefile test rather than a
ghci_script test. Hopefully making it a ghci_script test makes it more
robust.

Fixes #22313

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8cd6f435 by Curran McConnell at 2022-10-21T02:58:01-04:00
remove a no-warn directive from GHC.Cmm.ContFlowOpt

This patch is motivated by the desire to remove the {-# OPTIONS_GHC
-fno-warn-incomplete-patterns #-} directive at the top of
GHC.Cmm.ContFlowOpt. (Based on the text in this coding standards doc, I
understand it's a goal of the project to remove such directives.) I
chose this task because I'm a new contributor to GHC, and it seemed like
a good way to get acquainted with the patching process.

In order to address the warning that arose when I removed the no-warn
directive, I added a case to removeUnreachableBlocksProc to handle the
CmmData constructor. Clearly, since this partial function has not been
erroring out in the wild, its inputs are always in practice wrapped by
the CmmProc constructor. Therefore the CmmData case is handled by a
precise panic (which is an improvement over the partial pattern match
from before).

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a2af7c4c by Nicolas Trangez at 2022-10-21T02:58:39-04:00
build: get rid of `HAVE_TIME_H`

As advertized by `autoreconf`:

> All current systems provide time.h; it need not be checked for.

Hence, remove the check for it in `configure.ac` and remove conditional
inclusion of the header in `HAVE_TIME_H` blocks where applicable.

The `time.h` header was being included in various source files without a
`HAVE_TIME_H` guard already anyway.

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25cdc630 by Nicolas Trangez at 2022-10-21T02:58:39-04:00
rts: remove use of `TIME_WITH_SYS_TIME`

`autoreconf` will insert an `m4_warning` when the obsolescent
`AC_HEADER_TIME` macro is used:

> Update your code to rely only on HAVE_SYS_TIME_H,
> then remove this warning and the obsolete code below it.
> All current systems provide time.h; it need not be checked for.
> Not all systems provide sys/time.h, but those that do, all allow
> you to include it and time.h simultaneously.

Presence of `sys/time.h` was already checked in an earlier
`AC_CHECK_HEADERS` invocation, so `AC_HEADER_TIME` can be dropped and
guards relying on `TIME_WITH_SYS_TIME` can be reworked to
(unconditionally) include `time.h` and include `sys/time.h` based on
`HAVE_SYS_TIME_H`.

Note the documentation of `AC_HEADER_TIME` in (at least) Autoconf 2.67
says

> This macro is obsolescent, as current systems can include both files
> when they exist. New programs need not use this macro.

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1fe7921c by Eric Lindblad at 2022-10-21T02:59:21-04:00
runhaskell
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e3b3986e by David Feuer at 2022-10-21T03:00:00-04:00
Document how to quote certain names with spaces

Quoting a name for Template Haskell is a bit tricky if the second
character of that name is a single quote. The User's Guide falsely
claimed that it was impossible. Document how to do it.

Fixes #22236
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0eba81e8 by Krzysztof Gogolewski at 2022-10-21T03:00:00-04:00
Fix syntax
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c7f5f729 by Simon Peyton Jones at 2022-10-21T09:28:11+00:00
Fix binder-swap bug

This patch fixes #21229 properly, by avoiding doing a
binder-swap on dictionary Ids.  This is pretty subtle, and explained
in Note [Care with binder-swap on dictionaries].

Test is already in simplCore/should_run/T21229

This allows us to restore a feature to the specialiser that we had
to revert: see Note [Specialising polymorphic dictionaries].
(This is done in a separate patch.)

I also modularised things, using a new function scrutBinderSwap_maybe
in all the places where we are (effectively) doing a binder-swap,
notably

* Simplify.Iteration.addAltUnfoldings
* SpecConstr.extendCaseBndrs

In Simplify.Iteration.addAltUnfoldings I also eliminated a guard
    Many <- idMult case_bndr
because we concluded, in #22123, that it was doing no good.

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a6062746 by Simon Peyton Jones at 2022-10-21T09:28:11+00:00
Make the specialiser handle polymorphic specialisation

Ticket #13873 unexpectedly showed that a SPECIALISE pragma made a
program run (a lot) slower, because less specialisation took place
overall. It turned out that the specialiser was missing opportunities
because of quantified type variables.

It was quite easy to fix. The story is given in
    Note [Specialising polymorphic dictionaries]

Two other minor fixes in the specialiser

* There is no benefit in specialising data constructor /wrappers/.
  (They can appear overloaded because they are given a dictionary
  to store in the constructor.)  Small guard in canSpecImport.

* There was a buglet in the UnspecArg case of specHeader, in the
  case where there is a dead binder. We need a LitRubbish filler
  for the specUnfolding stuff.  I expanded
  Note [Drop dead args from specialisations] to explain.

There is a 4% increase in compile time for T15164, because we generate
more specialised code.  This seems OK.

Metric Increase:
    T15164

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30 changed files:

- compiler/GHC/Cmm/ContFlowOpt.hs
- compiler/GHC/Cmm/Pipeline.hs
- compiler/GHC/Core/Opt/OccurAnal.hs
- compiler/GHC/Core/Opt/SetLevels.hs
- compiler/GHC/Core/Opt/Simplify/Env.hs
- compiler/GHC/Core/Opt/Simplify/Iteration.hs
- compiler/GHC/Core/Opt/SpecConstr.hs
- compiler/GHC/Core/Opt/Specialise.hs
- compiler/GHC/Core/Subst.hs
- compiler/GHC/Core/Type.hs
- compiler/GHC/CoreToStg.hs
- + compiler/GHC/Driver/Config/CoreToStg.hs
- compiler/GHC/Driver/Main.hs
- compiler/ghc.cabal.in
- configure.ac
- docs/users_guide/exts/template_haskell.rst
- docs/users_guide/runghc.rst
- libraries/base/System/CPUTime/Posix/ClockGetTime.hsc
- libraries/base/aclocal.m4
- libraries/base/cbits/sysconf.c
- libraries/base/include/HsBase.h
- m4/fp_check_timer_create.m4
- rts/RtsUtils.c
- rts/posix/Clock.h
- rts/posix/ticker/Pthread.c
- rts/posix/ticker/Setitimer.c
- rts/win32/GetTime.c
- testsuite/tests/driver/fat-iface/Makefile
- testsuite/tests/driver/fat-iface/all.T
- testsuite/tests/linters/notes.stdout

The diff was not included because it is too large.

View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/a1b2d610999d3e697e598c080195f1c0f1b5aa54...a6062746fd68e3aef399031c7a9978baf5728881

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