Commit Graph

63 Commits

Author SHA1 Message Date
Jonathan Roelofs 1148f004fa Fix PR45371: SeparateConstOffsetFromGEP clean up bookkeeping
find() was altering the UserChain, even in cases where it subsequently
discovered that the resulting constant was a 0. This confuses
rebuildWithoutConstOffset() when it attempts to walk the chain later, since it
is expected that the chain itself be a path down the use-def edges of an
expression.
2020-04-01 12:38:15 -06:00
Drew Wock 0bcfafc5e7 [SeparateConstOffsetFromGEP] Fix: sext(a) + sext(b) -> sext(a + b) matches add and sub instructions with one another
During the SeparateConstOffsetFromGEP pass, signed extensions are distributed
to the values that feed into them and then later recombined. The recombination
stage is somewhat problematic- it doesn't differ add and sub instructions
from another when matching the sext(a) +/- sext(b) -> sext(a +/- b) pattern
in some instances.

An example- the IR contains:
%unextendedA
%unextendedB
%subuAuB = unextendedA - unextendedB
%extA = extend A
%extB = extend B
%addeAeB = extA + extB

The problematic optimization will transform that into:

%unextendedA
%unextendedB
%subuAuB = unextendedA - unextendedB
%extA = extend A
%extB = extend B
%addeAeB = extend subuAuB ; Obviously not semantically equivalent to the IR input.

This patch fixes that.

Patch by Drew Wock <drew.wock@sas.com>
Differential Revision: https://reviews.llvm.org/D65967
2020-01-17 12:22:52 -05:00
Reid Kleckner 05da2fe521 Sink all InitializePasses.h includes
This file lists every pass in LLVM, and is included by Pass.h, which is
very popular. Every time we add, remove, or rename a pass in LLVM, it
caused lots of recompilation.

I found this fact by looking at this table, which is sorted by the
number of times a file was changed over the last 100,000 git commits
multiplied by the number of object files that depend on it in the
current checkout:
  recompiles    touches affected_files  header
  342380        95      3604    llvm/include/llvm/ADT/STLExtras.h
  314730        234     1345    llvm/include/llvm/InitializePasses.h
  307036        118     2602    llvm/include/llvm/ADT/APInt.h
  213049        59      3611    llvm/include/llvm/Support/MathExtras.h
  170422        47      3626    llvm/include/llvm/Support/Compiler.h
  162225        45      3605    llvm/include/llvm/ADT/Optional.h
  158319        63      2513    llvm/include/llvm/ADT/Triple.h
  140322        39      3598    llvm/include/llvm/ADT/StringRef.h
  137647        59      2333    llvm/include/llvm/Support/Error.h
  131619        73      1803    llvm/include/llvm/Support/FileSystem.h

Before this change, touching InitializePasses.h would cause 1345 files
to recompile. After this change, touching it only causes 550 compiles in
an incremental rebuild.

Reviewers: bkramer, asbirlea, bollu, jdoerfert

Differential Revision: https://reviews.llvm.org/D70211
2019-11-13 16:34:37 -08:00
Teresa Johnson 9c27b59cec Change TargetLibraryInfo analysis passes to always require Function
Summary:
This is the first change to enable the TLI to be built per-function so
that -fno-builtin* handling can be migrated to use function attributes.
See discussion on D61634 for background. This is an enabler for fixing
handling of these options for LTO, for example.

This change should not affect behavior, as the provided function is not
yet used to build a specifically per-function TLI, but rather enables
that migration.

Most of the changes were very mechanical, e.g. passing a Function to the
legacy analysis pass's getTLI interface, or in Module level cases,
adding a callback. This is similar to the way the per-function TTI
analysis works.

There was one place where we were looking for builtins but not in the
context of a specific function. See FindCXAAtExit in
lib/Transforms/IPO/GlobalOpt.cpp. I'm somewhat concerned my workaround
could provide the wrong behavior in some corner cases. Suggestions
welcome.

Reviewers: chandlerc, hfinkel

Subscribers: arsenm, dschuff, jvesely, nhaehnle, mehdi_amini, javed.absar, sbc100, jgravelle-google, eraman, aheejin, steven_wu, george.burgess.iv, dexonsmith, jfb, asbirlea, gchatelet, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D66428

llvm-svn: 371284
2019-09-07 03:09:36 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Hiroshi Inoue f209649dfc [NFC] fix trivial typos in comments
llvm-svn: 334687
2018-06-14 05:41:49 +00:00
David Blaikie 31b98d2e99 Move Analysis/Utils/Local.h back to Transforms
Review feedback from r328165. Split out just the one function from the
file that's used by Analysis. (As chandlerc pointed out, the original
change only moved the header and not the implementation anyway - which
was fine for the one function that was used (since it's a
template/inlined in the header) but not in general)

llvm-svn: 333954
2018-06-04 21:23:21 +00:00
Artem Belevich c2cd5d5ce0 [Split GEP] handle trunc() in separate-const-offset-from-gep pass.
Let separate-const-offset-from-gep pass handle trunc() when it calculates
constant offset relative to base. The pass itself may insert trunc()
instructions when it canonicalises array indices to pointer-size integers
and needs to handle trunc() in order to evaluate the offset.

Differential Revision: https://reviews.llvm.org/D46732

llvm-svn: 332142
2018-05-11 21:13:19 +00:00
Adrian Prantl 5f8f34e459 Remove \brief commands from doxygen comments.
We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.

Patch produced by

  for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done

Differential Revision: https://reviews.llvm.org/D46290

llvm-svn: 331272
2018-05-01 15:54:18 +00:00
Roman Lebedev 25cbb62d18 [NFC] ConstantOffsetExtractor::CanTraceInto(): add FIXME: no tests
As suggested in https://reviews.llvm.org/D45631#1068338,
looking at haveNoCommonBitsSet() users, and *trying* to
show the change effect elsewhere.

llvm-svn: 330100
2018-04-15 18:59:27 +00:00
David Blaikie 8ad9a97310 Plumb useAA through TargetTransformInfo to remove Transforms->CodeGen header dependency
Thanks to echristo for the pointers on direction.

llvm-svn: 328737
2018-03-28 22:28:50 +00:00
David Blaikie 2be3922807 Fix a couple of layering violations in Transforms
Remove #include of Transforms/Scalar.h from Transform/Utils to fix layering.

Transforms depends on Transforms/Utils, not the other way around. So
remove the header and the "createStripGCRelocatesPass" function
declaration (& definition) that is unused and motivated this dependency.

Move Transforms/Utils/Local.h into Analysis because it's used by
Analysis/MemoryBuiltins.cpp.

llvm-svn: 328165
2018-03-21 22:34:23 +00:00
Elena Demikhovsky 945b7e5aa6 Adding a width of the GEP index to the Data Layout.
Making a width of GEP Index, which is used for address calculation, to be one of the pointer properties in the Data Layout.
p[address space]:size:memory_size:alignment:pref_alignment:index_size_in_bits.
The index size parameter is optional, if not specified, it is equal to the pointer size.

Till now, the InstCombiner normalized GEPs and extended the Index operand to the pointer width.
It works fine if you can convert pointer to integer for address calculation and all registered targets do this.
But some ISAs have very restricted instruction set for the pointer calculation. During discussions were desided to retrieve information for GEP index from the Data Layout.
http://lists.llvm.org/pipermail/llvm-dev/2018-January/120416.html

I added an interface to the Data Layout and I changed the InstCombiner and some other passes to take the Index width into account.
This change does not affect any in-tree target. I added tests to cover data layouts with explicitly specified index size.

Differential Revision: https://reviews.llvm.org/D42123

llvm-svn: 325102
2018-02-14 06:58:08 +00:00
Marek Olsak 8e7d149a31 [SeparateConstOffsetFromGEP] Preserve metadata when splitting GEPs
Summary:
!amdgpu.uniform needs to be preserved for AMDGPU, otherwise bad things
happen.

Reviewers: arsenm, nhaehnle, jingyue, broune, majnemer, bjarke.roune, dblaikie

Subscribers: wdng, tpr, llvm-commits

Differential Revision: https://reviews.llvm.org/D42744

llvm-svn: 323907
2018-01-31 20:17:52 +00:00
Haicheng Wu 5b106ef92e [SeparateConstOffsetFromGEP] Fix a typo. NFC.
do CSE for to => do CSE to

llvm-svn: 321098
2017-12-19 18:49:21 +00:00
David Blaikie b3bde2ea50 Fix a bunch more layering of CodeGen headers that are in Target
All these headers already depend on CodeGen headers so moving them into
CodeGen fixes the layering (since CodeGen depends on Target, not the
other way around).

llvm-svn: 318490
2017-11-17 01:07:10 +00:00
Eugene Zelenko 5adb96cc92 [Transforms] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).
llvm-svn: 316630
2017-10-26 00:55:39 +00:00
Chandler Carruth 6bda14b313 Sort the remaining #include lines in include/... and lib/....
I did this a long time ago with a janky python script, but now
clang-format has built-in support for this. I fed clang-format every
line with a #include and let it re-sort things according to the precise
LLVM rules for include ordering baked into clang-format these days.

I've reverted a number of files where the results of sorting includes
isn't healthy. Either places where we have legacy code relying on
particular include ordering (where possible, I'll fix these separately)
or where we have particular formatting around #include lines that
I didn't want to disturb in this patch.

This patch is *entirely* mechanical. If you get merge conflicts or
anything, just ignore the changes in this patch and run clang-format
over your #include lines in the files.

Sorry for any noise here, but it is important to keep these things
stable. I was seeing an increasing number of patches with irrelevant
re-ordering of #include lines because clang-format was used. This patch
at least isolates that churn, makes it easy to skip when resolving
conflicts, and gets us to a clean baseline (again).

llvm-svn: 304787
2017-06-06 11:49:48 +00:00
Sanjoy Das 08989c7ecd Rename isKnownNotFullPoison to programUndefinedIfPoison; NFC
Summary:
programUndefinedIfPoison makes more sense, given what the function
does; and I'm about to add a function with a name similar to
isKnownNotFullPoison (so do the rename to avoid confusion).

Reviewers: broune, majnemer, bjarke.roune

Reviewed By: broune

Subscribers: mcrosier, llvm-commits, mzolotukhin

Differential Revision: https://reviews.llvm.org/D30444

llvm-svn: 301776
2017-04-30 19:41:19 +00:00
Daniel Jasper aec2fa352f Revert @llvm.assume with operator bundles (r289755-r289757)
This creates non-linear behavior in the inliner (see more details in
r289755's commit thread).

llvm-svn: 290086
2016-12-19 08:22:17 +00:00
Hal Finkel 3ca4a6bcf1 Remove the AssumptionCache
After r289755, the AssumptionCache is no longer needed. Variables affected by
assumptions are now found by using the new operand-bundle-based scheme. This
new scheme is more computationally efficient, and also we need much less
code...

llvm-svn: 289756
2016-12-15 03:02:15 +00:00
Peter Collingbourne ab85225be4 IR: Change the gep_type_iterator API to avoid always exposing the "current" type.
Instead, expose whether the current type is an array or a struct, if an array
what the upper bound is, and if a struct the struct type itself. This is
in preparation for a later change which will make PointerType derive from
Type rather than SequentialType.

Differential Revision: https://reviews.llvm.org/D26594

llvm-svn: 288458
2016-12-02 02:24:42 +00:00
Daniel Berlin 11da66fc10 Partially revert 279331, as we modify this instruction in the loop
llvm-svn: 279335
2016-08-19 22:18:38 +00:00
Daniel Berlin a36f46363f Convert some depth first traversals to depth_first
llvm-svn: 279331
2016-08-19 22:06:23 +00:00
Tim Shen b5e0f5ac95 [GraphTraits] Make nodes_iterator dereference to NodeType*/NodeRef
Currently nodes_iterator may dereference to a NodeType* or a NodeType&. Make them all dereference to NodeType*, which is NodeRef later.

Differential Revision: https://reviews.llvm.org/D23704
Differential Revision: https://reviews.llvm.org/D23705

llvm-svn: 279326
2016-08-19 21:20:13 +00:00
Benjamin Kramer 135f735af1 Apply clang-tidy's modernize-loop-convert to most of lib/Transforms.
Only minor manual fixes. No functionality change intended.

llvm-svn: 273808
2016-06-26 12:28:59 +00:00
Andrew Kaylor aa641a5171 Re-commit optimization bisect support (r267022) without new pass manager support.
The original commit was reverted because of a buildbot problem with LazyCallGraph::SCC handling (not related to the OptBisect handling).

Differential Revision: http://reviews.llvm.org/D19172

llvm-svn: 267231
2016-04-22 22:06:11 +00:00
Vedant Kumar 6013f45f92 Revert "Initial implementation of optimization bisect support."
This reverts commit r267022, due to an ASan failure:

  http://lab.llvm.org:8080/green/job/clang-stage2-cmake-RgSan_check/1549

llvm-svn: 267115
2016-04-22 06:51:37 +00:00
Andrew Kaylor f0f279291c Initial implementation of optimization bisect support.
This patch implements a optimization bisect feature, which will allow optimizations to be selectively disabled at compile time in order to track down test failures that are caused by incorrect optimizations.

The bisection is enabled using a new command line option (-opt-bisect-limit).  Individual passes that may be skipped call the OptBisect object (via an LLVMContext) to see if they should be skipped based on the bisect limit.  A finer level of control (disabling individual transformations) can be managed through an addition OptBisect method, but this is not yet used.

The skip checking in this implementation is based on (and replaces) the skipOptnoneFunction check.  Where that check was being called, a new call has been inserted in its place which checks the bisect limit and the optnone attribute.  A new function call has been added for module and SCC passes that behaves in a similar way.

Differential Revision: http://reviews.llvm.org/D19172

llvm-svn: 267022
2016-04-21 17:58:54 +00:00
Lawrence Hu 84e6f1dd70 Bug fix: use dyn_cast_or_null instead of dyn_cast
Differential Revision: http://reviews.llvm.org/D17154

llvm-svn: 261299
2016-02-19 02:17:07 +00:00
Eduard Burtescu 19eb03106d [opaque pointer types] [NFC] GEP: replace get(Pointer)ElementType uses with get{Source,Result}ElementType.
Summary:
GEPOperator: provide getResultElementType alongside getSourceElementType.
This is made possible by adding a result element type field to GetElementPtrConstantExpr, which GetElementPtrInst already has.

GEP: replace get(Pointer)ElementType uses with get{Source,Result}ElementType.

Reviewers: mjacob, dblaikie

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D16275

llvm-svn: 258145
2016-01-19 17:28:00 +00:00
Craig Topper 66059c9f4d Replace dyn_cast with isa in places that weren't using the returned value for more than a boolean check. NFC.
llvm-svn: 253441
2015-11-18 07:07:59 +00:00
Duncan P. N. Exon Smith be4d8cba1c Scalar: Remove remaining ilist iterator implicit conversions
Remove remaining `ilist_iterator` implicit conversions from
LLVMScalarOpts.

This change exposed some scary behaviour in
lib/Transforms/Scalar/SCCP.cpp around line 1770.  This patch changes a
call from `Function::begin()` to `&Function::front()`, since the return
was immediately being passed into another function that takes a
`Function*`.  `Function::front()` started to assert, since the function
was empty.  Note that `Function::end()` does not point at a legal
`Function*` -- it points at an `ilist_half_node` -- so the other
function was getting garbage before.  (I added the missing check for
`Function::isDeclaration()`.)

Otherwise, no functionality change intended.

llvm-svn: 250211
2015-10-13 19:26:58 +00:00
Lawrence Hu cac0b89289 Swap loop invariant GEP with loop variant GEP to allow more LICM.
This patch changes the order of GEPs generated by Splitting GEPs
    pass, specially when one of the GEPs has constant and the base is
    loop invariant, then we will generate the GEP with constant first
    when beneficial, to expose more cases for LICM.

    If originally Splitting GEP generate the following:
      do.body.i:
        %idxprom.i = sext i32 %shr.i to i64
        %2 = bitcast %typeD* %s to i8*
        %3 = shl i64 %idxprom.i, 2
        %uglygep = getelementptr i8, i8* %2, i64 %3
        %uglygep7 = getelementptr i8, i8* %uglygep, i64 1032
      ...
    Now it genereates:
      do.body.i:
        %idxprom.i = sext i32 %shr.i to i64
        %2 = bitcast %typeD* %s to i8*
        %3 = shl i64 %idxprom.i, 2
        %uglygep = getelementptr i8, i8* %2, i64 1032
        %uglygep7 = getelementptr i8, i8* %uglygep, i64 %3
      ...

    For no-loop cases, the original way of generating GEPs seems to
    expose more CSE cases, so we don't change the logic for no-loop
    cases, and only limit our change to the specific case we are
    interested in.

llvm-svn: 248420
2015-09-23 19:25:30 +00:00
Chandler Carruth 2f1fd1658f [PM] Port ScalarEvolution to the new pass manager.
This change makes ScalarEvolution a stand-alone object and just produces
one from a pass as needed. Making this work well requires making the
object movable, using references instead of overwritten pointers in
a number of places, and other refactorings.

I've also wired it up to the new pass manager and added a RUN line to
a test to exercise it under the new pass manager. This includes basic
printing support much like with other analyses.

But there is a big and somewhat scary change here. Prior to this patch
ScalarEvolution was never *actually* invalidated!!! Re-running the pass
just re-wired up the various other analyses and didn't remove any of the
existing entries in the SCEV caches or clear out anything at all. This
might seem OK as everything in SCEV that can uses ValueHandles to track
updates to the values that serve as SCEV keys. However, this still means
that as we ran SCEV over each function in the module, we kept
accumulating more and more SCEVs into the cache. At the end, we would
have a SCEV cache with every value that we ever needed a SCEV for in the
entire module!!! Yowzers. The releaseMemory routine would dump all of
this, but that isn't realy called during normal runs of the pipeline as
far as I can see.

To make matters worse, there *is* actually a key that we don't update
with value handles -- there is a map keyed off of Loop*s. Because
LoopInfo *does* release its memory from run to run, it is entirely
possible to run SCEV over one function, then over another function, and
then lookup a Loop* from the second function but find an entry inserted
for the first function! Ouch.

To make matters still worse, there are plenty of updates that *don't*
trip a value handle. It seems incredibly unlikely that today GVN or
another pass that invalidates SCEV can update values in *just* such
a way that a subsequent run of SCEV will incorrectly find lookups in
a cache, but it is theoretically possible and would be a nightmare to
debug.

With this refactoring, I've fixed all this by actually destroying and
recreating the ScalarEvolution object from run to run. Technically, this
could increase the amount of malloc traffic we see, but then again it is
also technically correct. ;] I don't actually think we're suffering from
tons of malloc traffic from SCEV because if we were, the fact that we
never clear the memory would seem more likely to have come up as an
actual problem before now. So, I've made the simple fix here. If in fact
there are serious issues with too much allocation and deallocation,
I can work on a clever fix that preserves the allocations (while
clearing the data) between each run, but I'd prefer to do that kind of
optimization with a test case / benchmark that shows why we need such
cleverness (and that can test that we actually make it faster). It's
possible that this will make some things faster by making the SCEV
caches have higher locality (due to being significantly smaller) so
until there is a clear benchmark, I think the simple change is best.

Differential Revision: http://reviews.llvm.org/D12063

llvm-svn: 245193
2015-08-17 02:08:17 +00:00
Jingyue Wu 1238f341ba [SeparateConstOffsetFromGEP] sext(a)+sext(b) => sext(a+b) when a+b can't sign-overflow.
Summary:
This patch implements my promised optimization to reunites certain sexts from
operands after we extract the constant offset. See the header comment of
reuniteExts for its motivation.

One key building block that enables this optimization is Bjarke's poison value
analysis (D11212). That helps to prove "a +nsw b" can't overflow.

Reviewers: broune

Subscribers: jholewinski, sanjoy, llvm-commits

Differential Revision: http://reviews.llvm.org/D12016

llvm-svn: 245003
2015-08-14 02:02:05 +00:00
Jingyue Wu 13a80eaceb [SeparateConstOffsetFromGEP] strengthen the inbounds attribute
We used to be over-conservative about preserving inbounds. Actually, the second
GEP (which applies the constant offset) can inherit the inbounds attribute of
the original GEP, because the resultant pointer is equivalent to that of the
original GEP. For example,

  x  = GEP inbounds a, i+5
    =>
  y = GEP a, i               // inbounds removed
  x = GEP inbounds y, 5      // inbounds preserved

llvm-svn: 244937
2015-08-13 18:48:49 +00:00
Matt Arsenault e81944fd5e SeparateConstOffsetFromGEP: Pass address space to isLegalAddressingMode
llvm-svn: 239262
2015-06-07 20:17:44 +00:00
Jingyue Wu ca32190379 [ValueTracking] refactor: extract method haveNoCommonBitsSet
Summary:
Extract method haveNoCommonBitsSet so that we don't have to duplicate this logic in
InstCombine and SeparateConstOffsetFromGEP.

This patch also makes SeparateConstOffsetFromGEP more precise by passing
DominatorTree to computeKnownBits.

Test Plan: value-tracking-domtree.ll that tests ValueTracking indeed leverages dominating conditions

Reviewers: broune, meheff, majnemer

Reviewed By: majnemer

Subscribers: jholewinski, llvm-commits

Differential Revision: http://reviews.llvm.org/D9734

llvm-svn: 237407
2015-05-14 23:53:19 +00:00
Michael Zolotukhin 10ed96bf09 Fix comment for NoCommonBits.
Maybe there is a better wording, but at least it should be technically
correct now.

llvm-svn: 235660
2015-04-23 22:55:48 +00:00
Jingyue Wu f763c3fd45 [SeparateConstOffsetFromGEP] garbage-collect intermediate instructions
Summary: so that we needn't run DCE after this pass.

Test Plan: removed -dce from the commandline in split-gep.ll and split-gep-and-gvn.ll

Reviewers: meheff

Subscribers: llvm-commits, HaoLiu, hfinkel, jholewinski

Differential Revision: http://reviews.llvm.org/D9096

llvm-svn: 235409
2015-04-21 19:53:18 +00:00
David Blaikie 93c5444fe0 [opaque pointer type] More GEP API migrations in IRBuilder uses
The plan here is to push the API changes out from the common components
(like Constant::getGetElementPtr and IRBuilder::CreateGEP related
functions) and just update callers to either pass the type if it's
obvious, or pass null.

Do this with LoadInst as well and anything else that comes up, then to
start porting specific uses to not pass null anymore - this may require
some refactoring in each case.

llvm-svn: 234042
2015-04-03 19:41:44 +00:00
David Blaikie 741c8f81e4 [opaque pointer type] Start migrating GEP creation to explicitly specify the pointee type
I'm just going to migrate these in a pretty ad-hoc & incremental way -
providing the backwards compatible API for now, then locally removing
it, fixing a few callers, adding it back in and commiting those callers.
Rinse, repeat.

The assertions should ensure that if I get this wrong we'll find out
about it and not just have one giant patch to revert, recommit, revert,
recommit, etc.

llvm-svn: 232240
2015-03-14 01:53:18 +00:00
Mehdi Amini a28d91d81b DataLayout is mandatory, update the API to reflect it with references.
Summary:
Now that the DataLayout is a mandatory part of the module, let's start
cleaning the codebase. This patch is a first attempt at doing that.

This patch is not exactly NFC as for instance some places were passing
a nullptr instead of the DataLayout, possibly just because there was a
default value on the DataLayout argument to many functions in the API.
Even though it is not purely NFC, there is no change in the
validation.

I turned as many pointer to DataLayout to references, this helped
figuring out all the places where a nullptr could come up.

I had initially a local version of this patch broken into over 30
independant, commits but some later commit were cleaning the API and
touching part of the code modified in the previous commits, so it
seemed cleaner without the intermediate state.

Test Plan:

Reviewers: echristo

Subscribers: llvm-commits

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 231740
2015-03-10 02:37:25 +00:00
Mehdi Amini 46a43556db Make DataLayout Non-Optional in the Module
Summary:
DataLayout keeps the string used for its creation.

As a side effect it is no longer needed in the Module.
This is "almost" NFC, the string is no longer
canonicalized, you can't rely on two "equals" DataLayout
having the same string returned by getStringRepresentation().

Get rid of DataLayoutPass: the DataLayout is in the Module

The DataLayout is "per-module", let's enforce this by not
duplicating it more than necessary.
One more step toward non-optionality of the DataLayout in the
module.

Make DataLayout Non-Optional in the Module

Module->getDataLayout() will never returns nullptr anymore.

Reviewers: echristo

Subscribers: resistor, llvm-commits, jholewinski

Differential Revision: http://reviews.llvm.org/D7992

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 231270
2015-03-04 18:43:29 +00:00
Chandler Carruth fdb9c573f7 [multiversion] Thread a function argument through all the callers of the
getTTI method used to get an actual TTI object.

No functionality changed. This just threads the argument and ensures
code like the inliner can correctly look up the callee's TTI rather than
using a fixed one.

The next change will use this to implement per-function subtarget usage
by TTI. The changes after that should eliminate the need for FTTI as that
will have become the default.

llvm-svn: 227730
2015-02-01 12:01:35 +00:00
Jingyue Wu 6c26bb63fe [SeparateConstOffsetFromGEP] skip optnone functions
llvm-svn: 227705
2015-02-01 02:34:41 +00:00
Jingyue Wu 6e091c8eab [SeparateConstOffsetFromGEP] set PreservesCFG flag
SeparateConstOffsetFromGEP does not change the shape of the control flow graph.

llvm-svn: 227704
2015-02-01 02:33:02 +00:00
Chandler Carruth 705b185f90 [PM] Change the core design of the TTI analysis to use a polymorphic
type erased interface and a single analysis pass rather than an
extremely complex analysis group.

The end result is that the TTI analysis can contain a type erased
implementation that supports the polymorphic TTI interface. We can build
one from a target-specific implementation or from a dummy one in the IR.

I've also factored all of the code into "mix-in"-able base classes,
including CRTP base classes to facilitate calling back up to the most
specialized form when delegating horizontally across the surface. These
aren't as clean as I would like and I'm planning to work on cleaning
some of this up, but I wanted to start by putting into the right form.

There are a number of reasons for this change, and this particular
design. The first and foremost reason is that an analysis group is
complete overkill, and the chaining delegation strategy was so opaque,
confusing, and high overhead that TTI was suffering greatly for it.
Several of the TTI functions had failed to be implemented in all places
because of the chaining-based delegation making there be no checking of
this. A few other functions were implemented with incorrect delegation.
The message to me was very clear working on this -- the delegation and
analysis group structure was too confusing to be useful here.

The other reason of course is that this is *much* more natural fit for
the new pass manager. This will lay the ground work for a type-erased
per-function info object that can look up the correct subtarget and even
cache it.

Yet another benefit is that this will significantly simplify the
interaction of the pass managers and the TargetMachine. See the future
work below.

The downside of this change is that it is very, very verbose. I'm going
to work to improve that, but it is somewhat an implementation necessity
in C++ to do type erasure. =/ I discussed this design really extensively
with Eric and Hal prior to going down this path, and afterward showed
them the result. No one was really thrilled with it, but there doesn't
seem to be a substantially better alternative. Using a base class and
virtual method dispatch would make the code much shorter, but as
discussed in the update to the programmer's manual and elsewhere,
a polymorphic interface feels like the more principled approach even if
this is perhaps the least compelling example of it. ;]

Ultimately, there is still a lot more to be done here, but this was the
huge chunk that I couldn't really split things out of because this was
the interface change to TTI. I've tried to minimize all the other parts
of this. The follow up work should include at least:

1) Improving the TargetMachine interface by having it directly return
   a TTI object. Because we have a non-pass object with value semantics
   and an internal type erasure mechanism, we can narrow the interface
   of the TargetMachine to *just* do what we need: build and return
   a TTI object that we can then insert into the pass pipeline.
2) Make the TTI object be fully specialized for a particular function.
   This will include splitting off a minimal form of it which is
   sufficient for the inliner and the old pass manager.
3) Add a new pass manager analysis which produces TTI objects from the
   target machine for each function. This may actually be done as part
   of #2 in order to use the new analysis to implement #2.
4) Work on narrowing the API between TTI and the targets so that it is
   easier to understand and less verbose to type erase.
5) Work on narrowing the API between TTI and its clients so that it is
   easier to understand and less verbose to forward.
6) Try to improve the CRTP-based delegation. I feel like this code is
   just a bit messy and exacerbating the complexity of implementing
   the TTI in each target.

Many thanks to Eric and Hal for their help here. I ended up blocked on
this somewhat more abruptly than I expected, and so I appreciate getting
it sorted out very quickly.

Differential Revision: http://reviews.llvm.org/D7293

llvm-svn: 227669
2015-01-31 03:43:40 +00:00
Eric Christopher e38c8d4aa9 Migrate SeparateConstOffsetFromGEP to use a Function with
getSubtarget.

llvm-svn: 227172
2015-01-27 07:16:37 +00:00