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Sylvain Henry authored Nov 22, 2018 and Ben Gamari committed Nov 22, 2018

In a previous patch we replaced some built-in literal constructors
(MachInt, MachWord, etc.) with a single LitNumber constructor.

In this patch we replace the `Mach` prefix of the remaining constructors
with `Lit` for consistency (e.g., LitChar, LitLabel, etc.).

Sadly the name `LitString` was already taken for a kind of FastString
and it would become misleading to have both `LitStr` (literal
constructor renamed after `MachStr`) and `LitString` (FastString
variant). Hence this patch renames the FastString variant `PtrString`
(which is more accurate) and the literal string constructor now uses the
least surprising `LitString` name.

Both `Literal` and `LitString/PtrString` have recently seen breaking
changes so doing this kind of renaming now shouldn't harm much.

Reviewers: hvr, goldfire, bgamari, simonmar, jrtc27, tdammers

Subscribers: tdammers, rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4881

This reverts commit adcb5fb4.

Kavon Farvardin authored Oct 04, 2018 and Ben Gamari committed Oct 04, 2018

- Fix for #13904 -- stop "trashing" callee-saved registers, since it is
  not actually doing anything useful.

- Fix for #14251 -- fixes the calling convention for functions passing
  raw SSE-register values by adding padding as needed to get the values
  in the right registers. This problem cropped up when some args were
  unused an dropped from the live list.

- Fixed a typo in 'readnone' attribute

- Added 'lower-expect' pass to level 0 LLVM optimization passes to
  improve block layout in LLVM for stack checks, etc.

Test Plan: `make test WAYS=optllvm` and `make test WAYS=llvm`

Reviewers: bgamari, simonmar, angerman

Reviewed By: angerman

Subscribers: rwbarton, carter

GHC Trac Issues: #13904, #14251

Differential Revision: https://phabricator.haskell.org/D5190

Summary:
This change makes it possible to generate a static 32-bit relative label
offset on x86_64. Currently we can only generate word-sized label
offsets.

This will be used in D4634 to shrink info tables.  See D4632 for more
details.

Test Plan: See D4632

Reviewers: bgamari, niteria, michalt, erikd, jrtc27, osa1

Subscribers: thomie, carter

Differential Revision: https://phabricator.haskell.org/D4633

Herbert Valerio Riedel authored Sep 19, 2017 and Ben Gamari committed Sep 19, 2017

This switches the compiler/ component to get compiled with
-XNoImplicitPrelude and a `import GhcPrelude` is inserted in all
modules.

This is motivated by the upcoming "Prelude" re-export of
`Semigroup((<>))` which would cause lots of name clashes in every
modulewhich imports also `Outputable`

Reviewers: austin, goldfire, bgamari, alanz, simonmar

Reviewed By: bgamari

Subscribers: goldfire, rwbarton, thomie, mpickering, bgamari

Differential Revision: https://phabricator.haskell.org/D3989

Our new CPP linter enforces this.

LLVM 3.8 was released a couple of months ago.

Test Plan: Build and test on x86_64/linux (perf-llvm) and armhf/linux.

Reviewers: austin, hvr, rwbarton, bgamari

Reviewed By: bgamari

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2382

rwbarton authored Jan 27, 2016 and Ben Gamari committed Jan 27, 2016

In an attempt to catch bugs involving using undef values, replace
undef literals by values likely to cause crashes or test failures.
We do this only when validating since it is a deoptimization.

This depends on D1857 to catch such bugs in the RTS (such as #11487).

Test Plan:
Did a build with
```
BuildFlavour = quick-llvm
SRC_HC_OPTS_STAGE1 = -fllvm-fill-undef-with-garbage
```
The build crashed when running ghc-stage2, as expected.

Reviewers: austin, bgamari

Reviewed By: bgamari

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D1858

Before this commit, GHC only supported LLVM 3.6. Now it only supports
LLVM 3.7 which was released in August 2015. LLVM version 3.6 and earlier
do not work on AArch64/Arm64, but 3.7 does.

Also:
* Add CC_Ghc constructor to LlvmCallConvention.
* Replace `maxSupportLlvmVersion`/`minSupportLlvmVersion` with
  a single `supportedLlvmVersion` variable.
* Get `supportedLlvmVersion` from version specified in configure.ac.
* Drop llvmVersion field from DynFlags (no longer needed because only
  one version is supported).

Test Plan: Validate on x86_64 and arm

Reviewers: bgamari, austin

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D1320

GHC Trac Issues: #10953

Pushed by mistacke before it was ready.

This reverts commit 5dc3db74.

Ben Gamari authored Oct 02, 2015 and Ben Gamari committed Oct 02, 2015

This fixes Trac #7883.

This adds proper support for,
  * `MO_AtomicRMW`
  * `MO_AtomicWrite`
  * `MO_CmpXChg`

Test Plan: Validate

Reviewers: rrnewton, austin

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D1282

GHC Trac Issues: #7883

Michal Terepeta authored Jul 04, 2015 and Ben Gamari committed Jul 04, 2015

This includes:

- Adding new LlvmType called LMStructP that represents an unpacked
  struct (this is necessary since LLVM's instructions the
  llvm.sadd.with.overflow.* return an unpacked struct).

- Modifications to LlvmCodeGen.CodeGen to generate the LLVM
  instructions for the primops.

- Modifications to StgCmmPrim to actually use those three instructions
  if we use the LLVM backend (so far they were only used for NCG).

Test Plan: validate

Reviewers: austin, rwbarton, bgamari

Reviewed By: bgamari

Subscribers: thomie, bgamari

Differential Revision: https://phabricator.haskell.org/D991

GHC Trac Issues: #9430

Ben Gamari authored Nov 21, 2014 and Herbert Valerio Riedel committed Nov 21, 2014

Due to changes in LLVM 3.5 aliases now may only refer to definitions.
Previously to handle symbols defined outside of the current commpilation
unit GHC would emit both an `external` declaration, as well as an alias
pointing to it, e.g.,

    @stg_BCO_info = external global i8
    @stg_BCO_info$alias = alias private i8* @stg_BCO_info

Where references to `stg_BCO_info` will use the alias
`stg_BCO_info$alias`. This is not permitted under the new alias
behavior, resulting in errors resembling,

    Alias must point to a definition
    i8* @"stg_BCO_info$alias"

To fix this, we invert the naming relationship between aliases and
definitions. That is, now the symbol definition takes the name
`@stg_BCO_info$def` and references use the actual name, `@stg_BCO_info`.
This means the external symbols can be handled by simply emitting an
`external` declaration,

    @stg_BCO_info = external global i8

Whereas in the case of a forward declaration we emit,

    @stg_BCO_info = alias private i8* @stg_BCO_info$def

Reviewed By: austin

Differential Revision: https://phabricator.haskell.org/D155

In some cases, the layout of the LANGUAGE/OPTIONS_GHC lines has been
reorganized, while following the convention, to

- place `{-# LANGUAGE #-}` pragmas at the top of the source file, before
  any `{-# OPTIONS_GHC #-}`-lines.

- Moreover, if the list of language extensions fit into a single
  `{-# LANGUAGE ... -#}`-line (shorter than 80 characters), keep it on one
  line. Otherwise split into `{-# LANGUAGE ... -#}`-lines for each
  individual language extension. In both cases, try to keep the
  enumeration alphabetically ordered.
  (The latter layout is preferable as it's more diff-friendly)

While at it, this also replaces obsolete `{-# OPTIONS ... #-}` pragma
occurences by `{-# OPTIONS_GHC ... #-}` pragmas.

Peter Wortmann authored Jun 26, 2013 and dterei committed Jun 27, 2013

This combined patch reworks the LLVM backend in a number of ways:

1. Most prominently, we introduce a LlvmM monad carrying the contents of
   the old LlvmEnv around. This patch completely removes LlvmEnv and
   refactors towards standard library monad combinators wherever possible.

2. Support for streaming - we can now generate chunks of Llvm for Cmm as
   it comes in. This might improve our speed.

3. To allow streaming, we need a more flexible way to handle forward
   references. The solution (getGlobalPtr) unifies LlvmCodeGen.Data
   and getHsFunc as well.

4. Skip alloca-allocation for registers that are actually never written.
   LLVM will automatically eliminate these, but output is smaller and
   friendlier to human eyes this way.

5. We use LlvmM to collect references for llvm.used. This allows places
   other than cmmProcLlvmGens to generate entries.

Peter Wortmann authored May 29, 2013 and dterei committed Jun 27, 2013

I am not quite sure at what point it makes sense to look at arrays as
pointers, but I ran into at least one use case that strongly suggested
doing it this way (calculating the actual size of structures, to be exact).

Peter Wortmann authored Jun 26, 2013 and dterei committed Jun 27, 2013

Also give them a proper constructor - getGlobalVar and getGlobalValue
map directly to the accessors.

Peter Wortmann authored Jun 26, 2013 and dterei committed Jun 27, 2013

This patch reworks some parts of the LLVM pretty-printing code that were
still using Show and String. Now we should be using SDoc and Outputable
throughout. Note that many get*Name functions become pp*Name
here as a side-effect.

Peter Wortmann authored Jun 21, 2013 and dterei committed Jun 27, 2013

- MetaArgs is not needed, as variables are already meta data

- Same goes for MetaVal - its only reason for existing seems to be to
  support LLVM's strange pretty-printing for meta-data annotations, and
  I feel that is better to keep the data structure clean and handle it in
  the pretty-printing instead.

- Rename "MetaData" to "MetaAnnot". Meta-data is still meta-data when it
  is not associated with an expression or statement - for example compile
  unit data for debugging. I feel the old name was a bit misleading.

- Make the renamed MetaAnnot a proper data type instead of a type alias
  for a pair.

- Rename "MetaExpr" constructor to "MetaStruct". As the data is much more
  like a LLVM structure (not array, as it can contain values).

- Fix a warning

backend.

This patch adds support for LLVM vectors and vector operations to our internal
LLVM abstract syntax data types.

The regular structure type adds padding to conform to the platform ABI,
which causes problems with structures storing doubles under windows since
we don't conform to the platform ABI there. So we use packed structures
instead now that don't do any padding.

Patch from Erik de Castro Lopo <erikd@mega-nerd.com>.

These allow annotations of the code produced by the backend
which should bring some perforamnce gains. At the moment
the attributes aren't being used though.