| Commit message (Collapse) | Author | Age | Files | Lines |
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This patch adds support for the s390x architecture for the LLVM code
generator. The patch includes a register mapping of STG registers onto
s390x machine registers which enables a registerised build.
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Add StgToCmm module hierarchy. Platform modules that are used in several
other places (NCG, LLVM codegen, Cmm transformations) are put into
GHC.Platform.
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There were two problems with LLVM version checking:
- The parser would only parse x and x.y formatted versions. E.g. 1.2.3
would be rejected.
- The version check was too strict and would reject x.y formatted
versions. E.g. when we support version 7 it'd reject 7.0 ("LLVM
version 7.0") and only accept 7 ("LLVM version 7").
We now parse versions with arbitrarily deep minor numbering (x.y.z.t...)
and accept versions as long as the major version matches the supported
version (e.g. 7.1, 7.1.2, 7.1.2.3 ...).
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This generalizes code generators (outputAsm, outputLlvm, outputC, and
the call site codeOutput) so that they'll return the return values of
the passed Cmm streams.
This allows accumulating data during Cmm generation and returning it to
the call site in HscMain.
Previously the Cmm streams were assumed to return (), so the code
generators returned () as well.
This change is required by !1304 and !1530.
Skipping CI as this was tested before and I only updated the commit
message.
[skip ci]
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Unfortunately this will require more work; register allocation is
quite broken.
This reverts commit acd795583625401c5554f8e04ec7efca18814011.
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This adds support for constructing vector types from Float#, Double# etc
and performing arithmetic operations on them
Cleaned-Up-By: Ben Gamari <ben@well-typed.com>
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Here the following changes are introduced:
- A read barrier machine op is added to Cmm.
- The order in which a closure's fields are read and written is changed.
- Memory barriers are added to RTS code to ensure correctness on
out-or-order machines with weak memory ordering.
Cmm has a new CallishMachOp called MO_ReadBarrier. On weak memory machines, this
is lowered to an instruction that ensures memory reads that occur after said
instruction in program order are not performed before reads coming before said
instruction in program order. On machines with strong memory ordering properties
(e.g. X86, SPARC in TSO mode) no such instruction is necessary, so
MO_ReadBarrier is simply erased. However, such an instruction is necessary on
weakly ordered machines, e.g. ARM and PowerPC.
Weam memory ordering has consequences for how closures are observed and mutated.
For example, consider a closure that needs to be updated to an indirection. In
order for the indirection to be safe for concurrent observers to enter, said
observers must read the indirection's info table before they read the
indirectee. Furthermore, the entering observer makes assumptions about the
closure based on its info table contents, e.g. an INFO_TYPE of IND imples the
closure has an indirectee pointer that is safe to follow.
When a closure is updated with an indirection, both its info table and its
indirectee must be written. With weak memory ordering, these two writes can be
arbitrarily reordered, and perhaps even interleaved with other threads' reads
and writes (in the absence of memory barrier instructions). Consider this
example of a bad reordering:
- An updater writes to a closure's info table (INFO_TYPE is now IND).
- A concurrent observer branches upon reading the closure's INFO_TYPE as IND.
- A concurrent observer reads the closure's indirectee and enters it. (!!!)
- An updater writes the closure's indirectee.
Here the update to the indirectee comes too late and the concurrent observer has
jumped off into the abyss. Speculative execution can also cause us issues,
consider:
- An observer is about to case on a value in closure's info table.
- The observer speculatively reads one or more of closure's fields.
- An updater writes to closure's info table.
- The observer takes a branch based on the new info table value, but with the
old closure fields!
- The updater writes to the closure's other fields, but its too late.
Because of these effects, reads and writes to a closure's info table must be
ordered carefully with respect to reads and writes to the closure's other
fields, and memory barriers must be placed to ensure that reads and writes occur
in program order. Specifically, updates to a closure must follow the following
pattern:
- Update the closure's (non-info table) fields.
- Write barrier.
- Update the closure's info table.
Observing a closure's fields must follow the following pattern:
- Read the closure's info pointer.
- Read barrier.
- Read the closure's (non-info table) fields.
This patch updates RTS code to obey this pattern. This should fix long-standing
SMP bugs on ARM (specifically newer aarch64 microarchitectures supporting
out-of-order execution) and PowerPC. This fixes issue #15449.
Co-Authored-By: Ben Gamari <ben@well-typed.com>
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LLVM version numberinf changed recently. Previously, releases were numbered
4.0, 5.0 and 6.0 but with version 7, they dropped the redundant ".0".
Fix requires for Llvm detection and some code.
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ghc-pkg needs to be aware of platforms so it can figure out which
subdire within the user package db to use. This is admittedly
roundabout, but maybe Cabal could use the same notion of a platform as
GHC to good affect too.
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Previously log and exp were primitives yet log1p and expm1 were FFI
calls. Fix this non-uniformity.
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1. If GHC is to be multi-target, these cannot be baked in at compile
time.
2. Compile-time flags have a higher maintenance than run-time flags.
3. The old way makes build system implementation (various bootstrapping
details) with the thing being built. E.g. GHC doesn't need to care
about which integer library *will* be used---this is purely a crutch
so the build system doesn't need to pass flags later when using that
library.
4. Experience with cross compilation in Nixpkgs has shown things work
nicer when compiler's can *optionally* delegate the bootstrapping the
package manager. The package manager knows the entire end-goal build
plan, and thus can make top-down decisions on bootstrapping. GHC can
just worry about GHC, not even core library like base and ghc-prim!
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When a new closure identifier is being established to a
local or exported closure already emitted into the same
module, refrain from adding an IND_STATIC closure, and
instead emit an assembly-language alias.
Inter-module IND_STATIC objects still remain, and need to be
addressed by other measures.
Binary-size savings on nofib are around 0.1%.
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* simplifies registers to have GPR, Float and Double, by removing the SSE2 and X87 Constructors
* makes -msse2 assumed/default for x86 platforms, fixing a long standing nondeterminism in rounding
behavior in 32bit haskell code
* removes the 80bit floating point representation from the supported float sizes
* theres still 1 tiny bit of x87 support needed,
for handling float and double return values in FFI calls wrt the C ABI on x86_32,
but this one piece does not leak into the rest of NCG.
* Lots of code thats not been touched in a long time got deleted as a
consequence of all of this
all in all, this change paves the way towards a lot of future further
improvements in how GHC handles floating point computations, along with
making the native code gen more accessible to a larger pool of contributors.
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This commit includes the necessary changes in code and
documentation to support a primop that reverses a word's
bits. It also includes a test.
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Also used ByteString in some other relevant places
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The alias is of type i8, so its global variable name
should have type i8*. Anyway we should never deal
with pointers to (i8*)!
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This patch fixes a fairly long-standing bug (dating back to 2015) in
RdrName.bestImport, namely
commit 9376249b6b78610db055a10d05f6592d6bbbea2f
Author: Simon Peyton Jones <simonpj@microsoft.com>
Date: Wed Oct 28 17:16:55 2015 +0000
Fix unused-import stuff in a better way
In that patch got the sense of the comparison back to front, and
thereby failed to implement the unused-import rules described in
Note [Choosing the best import declaration] in RdrName
This led to Trac #13064 and #15393
Fixing this bug revealed a bunch of unused imports in libraries;
the ones in the GHC repo are part of this commit.
The two important changes are
* Fix the bug in bestImport
* Modified the rules by adding (a) in
Note [Choosing the best import declaration] in RdrName
Reason: the previosu rules made Trac #5211 go bad again. And
the new rule (a) makes sense to me.
In unravalling this I also ended up doing a few other things
* Refactor RnNames.ImportDeclUsage to use a [GlobalRdrElt] for the
things that are used, rather than [AvailInfo]. This is simpler
and more direct.
* Rename greParentName to greParent_maybe, to follow GHC
naming conventions
* Delete dead code RdrName.greUsedRdrName
Bumps a few submodules.
Reviewers: hvr, goldfire, bgamari, simonmar, jrtc27
Subscribers: rwbarton, carter
Differential Revision: https://phabricator.haskell.org/D5312
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remove local
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This reverts commit adcb5fb47c0942671d409b940d8884daa9359ca4.
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This reverts commit d8495549ba9d194815c2d0eaee6797fc7c00756a.
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This fixes two isssues:
- Using bitcast for MO_XX_Conv
Arguments to a bitcast must be of the same size. We should be using
`trunc` and `zext` instead.
- Using unsupported MO_*_QuotRem for LLVM
The two primops `MO_*_QuotRem` are not supported by the LLVM backend,
so
we shouldn't use them for `Int8#`/`Word8#` (just as we do not use
them for
`Int#`/`Word#`).
Signed-off-by: Michal Terepeta <michal.terepeta@gmail.com>
Test Plan: manually run tests with WAY=llvm
Reviewers: bgamari, simonmar
Reviewed By: bgamari
Subscribers: rwbarton, carter
GHC Trac Issues: #15864
Differential Revision: https://phabricator.haskell.org/D5304
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This is the first step of implementing:
https://github.com/ghc-proposals/ghc-proposals/pull/74
The main highlights/changes:
primops.txt.pp gets two new sections for two new primitive types for
signed and unsigned 8-bit integers (Int8# and Word8 respectively) along
with basic arithmetic and comparison operations. PrimRep/RuntimeRep get
two new constructors for them. All of the primops translate into the
existing MachOPs.
For CmmCalls the codegen will now zero-extend the values at call
site (so that they can be moved to the right register) and then truncate
them back their original width.
x86 native codegen needed some updates, since it wasn't able to deal
with the new widths, but all the changes are quite localized. LLVM
backend seems to just work.
This is the second attempt at merging this, after the first attempt in
D4475 had to be backed out due to regressions on i386.
Bumps binary submodule.
Signed-off-by: Michal Terepeta <michal.terepeta@gmail.com>
Test Plan: ./validate (on both x86-{32,64})
Reviewers: bgamari, hvr, goldfire, simonmar
Subscribers: rwbarton, carter
Differential Revision: https://phabricator.haskell.org/D5258
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We now calculate the SSE register padding needed to fix the calling
convention in LLVM in a robust way: grouping them by whether
registers in that class overlap (with the same class overlapping
itself).
My prior patch assumed that no matter the platform, physical
register Fx aliases with Dx, etc, for our calling convention.
This is unfortunately not the case for any platform except x86-64.
Test Plan:
Only know how to test on x86-64, but it should be tested on ARM with:
`make test WAYS=llvm && make test WAYS=optllvm`
Reviewers: bgamari, angerman
Reviewed By: bgamari
Subscribers: rwbarton, carter
GHC Trac Issues: #15780, #14251, #15747
Differential Revision: https://phabricator.haskell.org/D5254
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This unfortunately broke i386 support since it introduced references to
byte-sized registers that don't exist on that architecture.
Reverts binary submodule
This reverts commit 5d5307f943d7581d7013ffe20af22233273fba06.
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This is the first step of implementing:
https://github.com/ghc-proposals/ghc-proposals/pull/74
The main highlights/changes:
- `primops.txt.pp` gets two new sections for two new primitive types
for signed and unsigned 8-bit integers (`Int8#` and `Word8`
respectively) along with basic arithmetic and comparison
operations. `PrimRep`/`RuntimeRep` get two new constructors for
them. All of the primops translate into the existing `MachOP`s.
- For `CmmCall`s the codegen will now zero-extend the values at call
site (so that they can be moved to the right register) and then
truncate them back their original width.
- x86 native codegen needed some updates, since it wasn't able to deal
with the new widths, but all the changes are quite localized. LLVM
backend seems to just work.
Bumps binary submodule.
Signed-off-by: Michal Terepeta <michal.terepeta@gmail.com>
Test Plan: ./validate with new tests
Reviewers: hvr, goldfire, bgamari, simonmar
Subscribers: Abhiroop, dfeuer, rwbarton, thomie, carter
Differential Revision: https://phabricator.haskell.org/D4475
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- 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
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Reviewers: hvr, bgamari, simonmar, jrtc27
Reviewed By: bgamari
Subscribers: alpmestan, rwbarton, thomie, carter
Differential Revision: https://phabricator.haskell.org/D5034
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Summary:
This contains two commits:
----
Make GHC's code-base compatible w/ `MonadFail`
There were a couple of use-sites which implicitly used pattern-matches
in `do`-notation even though the underlying `Monad` didn't explicitly
support `fail`
This refactoring turns those use-sites into explicit case
discrimations and adds an `MonadFail` instance for `UniqSM`
(`UniqSM` was the worst offender so this has been postponed for a
follow-up refactoring)
---
Turn on MonadFail desugaring by default
This finally implements the phase scheduled for GHC 8.6 according to
https://prime.haskell.org/wiki/Libraries/Proposals/MonadFail#Transitionalstrategy
This also preserves some tests that assumed MonadFail desugaring to be
active; all ghc boot libs were already made compatible with this
`MonadFail` long ago, so no changes were needed there.
Test Plan: Locally performed ./validate --fast
Reviewers: bgamari, simonmar, jrtc27, RyanGlScott
Reviewed By: bgamari
Subscribers: bgamari, RyanGlScott, rwbarton, thomie, carter
Differential Revision: https://phabricator.haskell.org/D5028
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Summary:
In D4592, `AddWordC` is lowered as an unsigned subtraction instead
of an unsigned addition when compiling with LLVM.
This patch rectifies that.
Reviewers: angerman, bgamari, monoidal
Reviewed By: angerman, bgamari, monoidal
Subscribers: osa1, rwbarton, thomie, carter
Differential Revision: https://phabricator.haskell.org/D4969
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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
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This is mostly for congruence with 'subWordC#' and '{add,sub}IntC#'.
I found 'plusWord2#' while implementing this, which both lacks
documentation and has a slightly different specification than
'addWordC#', which means the generic implementation is unnecessarily
complex.
While I was at it, I also added lacking meta-information on PrimOps
and refactored 'subWordC#'s generic implementation to be branchless.
Reviewers: bgamari, simonmar, jrtc27, dfeuer
Reviewed By: bgamari, dfeuer
Subscribers: dfeuer, thomie, carter
Differential Revision: https://phabricator.haskell.org/D4592
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This adds support for the bit deposit and extraction operations provided
by the BMI and BMI2 instruction set extensions on modern amd64 machines.
Implement x86 code generator for pdep and pext. Properly initialise
bmiVersion field.
pdep and pext test cases
Fix pattern match for pdep and pext instructions
Fix build of pdep and pext code for 32-bit architectures
Test Plan: Validate
Reviewers: austin, simonmar, bgamari, angerman
Reviewed By: bgamari
Subscribers: trommler, carter, angerman, thomie, rwbarton, newhoggy
GHC Trac Issues: #14206
Differential Revision: https://phabricator.haskell.org/D4236
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This broke the 32-bit build.
This reverts commit f5dc8ccc29429d0a1d011f62b6b430f6ae50290c.
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This adds support for the bit deposit and extraction operations provided
by the BMI and BMI2 instruction set extensions on modern amd64 machines.
Test Plan: Validate
Reviewers: austin, simonmar, bgamari, hvr, goldfire, erikd
Reviewed By: bgamari
Subscribers: goldfire, erikd, trommler, newhoggy, rwbarton, thomie
GHC Trac Issues: #14206
Differential Revision: https://phabricator.haskell.org/D4063
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Depends on D4090
Reviewers: austin, bgamari, erikd, simonmar, alexbiehl
Reviewed By: bgamari
Subscribers: rwbarton, thomie
Differential Revision: https://phabricator.haskell.org/D4091
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Here we add a flag to instruct the native code generator to add
alignment checks in all info table dereferences. This is helpful in
catching pointer tagging issues.
Thanks to @jrtc27 for uncovering the tagging issues on Sparc which
inspired this flag.
Test Plan: Validate
Reviewers: simonmar, austin, erikd
Reviewed By: simonmar
Subscribers: rwbarton, trofi, thomie, jrtc27
Differential Revision: https://phabricator.haskell.org/D4101
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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
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IOW, code compiles -Wnoncanonical-monoid-instances clean now
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The LLVM backend shells out to LLVMs `opt` and `llc` tools. This clean
up introduces a shared data structure to carry the arguments we pass to
each tool so that corresponding flags are next to each other. It drops
the hard coded data layouts in favor of using `-mtriple` and have LLVM
infer them. Furthermore we add `clang` as a proper tool, so we don't
rely on assuming that `clang` is called `clang` on the `PATH` when using
`clang` as the assembler. Finally this diff also changes the type of
`optLevel` from `Int` to `Word`, as we do not have negative optimization
levels.
Reviewers: erikd, hvr, austin, rwbarton, bgamari, kavon
Reviewed By: kavon
Subscribers: michalt, Ericson2314, ryantrinkle, dfeuer, carter, simonpj,
kavon, simonmar, thomie, erikd, snowleopard
Differential Revision: https://phabricator.haskell.org/D3352
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GHC 8.2.1 is out, so now GHC's support window only extends back to GHC
8.0. This means we can delete gobs of code that was only used for GHC
7.10 support. Hooray!
Test Plan: ./validate
Reviewers: hvr, bgamari, austin, goldfire, simonmar
Reviewed By: bgamari
Subscribers: Phyx, rwbarton, thomie
Differential Revision: https://phabricator.haskell.org/D3781
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Summary:
Initial implementation of split-section on Windows.
This also corrects section namings and uses the platform
convention of `$` instead of `.` to separate sections.
Implementation is based on @awson's patches to binutils.
Binutils requires some extra help when compiling the libraries
for GHCi usage. We drop the `-T` and use implicit scripts to amend
the linker scripts instead of replacing it.
Because of these very large GHCi object files, we need big-obj support,
which will be added by another patch.
Test Plan: ./validate
Reviewers: awson, austin, bgamari
Subscribers: dfeuer, rwbarton, thomie, snowleopard, #ghc_windows_task_force
GHC Trac Issues: #12913
Differential Revision: https://phabricator.haskell.org/D3383
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This copies the subset of Hoopl's functionality needed by GHC to
`cmm/Hoopl` and removes the dependency on the Hoopl package.
The main motivation for this change is the confusing/noisy interface
between GHC and Hoopl:
- Hoopl has `Label` which is GHC's `BlockId` but different than
GHC's `CLabel`
- Hoopl has `Unique` which is different than GHC's `Unique`
- Hoopl has `Unique{Map,Set}` which are different than GHC's
`Uniq{FM,Set}`
- GHC has its own specialized copy of `Dataflow`, so `cmm/Hoopl` is
needed just to filter the exposed functions (filter out some of the
Hoopl's and add the GHC ones)
With this change, we'll be able to simplify this significantly.
It'll also be much easier to do invasive changes (Hoopl is a public
package on Hackage with users that depend on the current behavior)
This should introduce no changes in functionality - it merely
copies the relevant code.
Signed-off-by: Michal Terepeta <michal.terepeta@gmail.com>
Test Plan: ./validate
Reviewers: austin, bgamari, simonmar
Reviewed By: bgamari, simonmar
Subscribers: simonpj, kavon, rwbarton, thomie
Differential Revision: https://phabricator.haskell.org/D3616
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This reverts commit 667abf17dced8b4a4cd2dc6a291a6f244ffa031f.
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This reverses commit 1686f30951292e94bf3076ce8b3eafb0bcbba91d (Mangle
.subsections_via_symbols away., D3287), and implements proper support
for `-dead_strip` via the injection of `.alt_entry` symbols for the
function definition pointing to the beginning of the prefix data.
This is the result of a lengthy discussion with rwbarton, and the
following llvm-dev mailing list thread:
http://lists.llvm.org/pipermail/llvm-dev/2017-March/110733.html
The essential problem is that there is no reference from a function to
its info table. This combined with `.subsections_via_symbols`, which
llvm emits unconditionally, leads the linker to believe that the prefix
data is unnecessary and stripping it away if presented with the
`-dead_strip` flag.
The NCG has for this purpose special $dsp (dead strip preventer) symbols
and adds a relocation to the end of each function body pointing to that
function's $dsp symbol. We cannot easily do the same thing via LLVM.
Instead we use the `.alt_entry` directive on the function symbol, which
causes the linker to treat it as a continuation of the previous symbol,
namely the $dsp symbol. As a result the function body will not be
separated from its info table.
Reviewers: erikd, austin, rwbarton, bgamari
Reviewed By: bgamari
Subscribers: michalt, thomie
Differential Revision: https://phabricator.haskell.org/D3290
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Our new CPP linter enforces this.
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