Commit Graph

7820 Commits

Author SHA1 Message Date
Renato Golin 038ede2a16 [NFC] Consolidate six getPointerOperand() utility functions into one place
There are six separate instances of getPointerOperand() utility.
LoopVectorize.cpp has one of them,
and I don't want to create a 7th one while I'm trying to move
LoopVectorizationLegality into a separate file
(eventual objective is to move it to Analysis tree).

See http://lists.llvm.org/pipermail/llvm-dev/2018-February/120999.html
for llvm-dev discussions

Closes D43323.

Patch by Hideki Saito <hideki.saito@intel.com>.

llvm-svn: 327173
2018-03-09 21:05:58 +00:00
Philip Reames fbffd126b8 [NFC] Factor out a helper function for checking if a block has a potential early implicit exit.
llvm-svn: 327065
2018-03-08 21:25:30 +00:00
Alina Sbirlea d90c9f4a3c Expose must/may alias info in MemorySSA.
Summary:
Building MemorySSA gathers alias information for Defs/Uses.
Store and expose this information when optimizing uses (when building MemorySSA),
and when optimizing defs or updating uses (getClobberingMemoryAccess).
Current patch does not propagate alias information through MemoryPhis.

Reviewers: gbiv, dberlin

Subscribers: Prazek, sanjoy, llvm-commits

Differential Revision: https://reviews.llvm.org/D38569

llvm-svn: 327035
2018-03-08 18:03:14 +00:00
Sebastian Pop bf6e1c26cf DA: remove uses of GEP, only ask SCEV
It's been quite some time the Dependence Analysis (DA) is broken,
as it uses the GEP representation to "identify" multi-dimensional arrays.
It even wrongly detects multi-dimensional arrays in single nested loops:

from test/Analysis/DependenceAnalysis/Coupled.ll, example @couple6
;; for (long int i = 0; i < 50; i++) {
;; A[i][3*i - 6] = i;
;; *B++ = A[i][i];

DA used to detect two subscripts, which makes no sense in the LLVM IR
or in C/C++ semantics, as there are no guarantees as in Fortran of
subscripts not overlapping into a next array dimension:

maximum nesting levels = 1
SrcPtrSCEV = %A
DstPtrSCEV = %A
using GEPs
subscript 0
    src = {0,+,1}<nuw><nsw><%for.body>
    dst = {0,+,1}<nuw><nsw><%for.body>
    class = 1
    loops = {1}
subscript 1
    src = {-6,+,3}<nsw><%for.body>
    dst = {0,+,1}<nuw><nsw><%for.body>
    class = 1
    loops = {1}
Separable = {}
Coupled = {1}

With the current patch, DA will correctly work on only one dimension:

maximum nesting levels = 1
SrcSCEV = {(-2424 + %A)<nsw>,+,1212}<%for.body>
DstSCEV = {%A,+,404}<%for.body>
subscript 0
    src = {(-2424 + %A)<nsw>,+,1212}<%for.body>
    dst = {%A,+,404}<%for.body>
    class = 1
    loops = {1}
Separable = {0}
Coupled = {}

This change removes all uses of GEP from DA, and we now only rely
on the SCEV representation.

The patch does not turn on -da-delinearize by default, and so the DA analysis
will be more conservative in the case of multi-dimensional memory accesses in
nested loops.

I disabled some interchange tests, as the DA is not able to disambiguate
the dependence anymore. To make DA stronger, we may need to
compute a bound on the number of iterations based on the access functions
and array dimensions.

The patch cleans up all the CHECKs in test/Transforms/LoopInterchange/*.ll to
avoid checking for snippets of LLVM IR: this form of checking is very hard to
maintain. Instead, we now check for output of the pass that are more meaningful
than dozens of lines of LLVM IR. Some tests now require -debug messages and thus
only enabled with asserts.

Patch written by Sebastian Pop and Aditya Kumar.

Differential Revision: https://reviews.llvm.org/D35430

llvm-svn: 326837
2018-03-06 21:55:59 +00:00
Sanjay Patel 7ed0bc26ac [ValueTracking] move helpers for SelectPatterns from InstCombine to ValueTracking
Most of the folds based on SelectPatternResult belong in InstSimplify rather than
InstCombine, so the helper code should be available to other passes/analysis.

llvm-svn: 326812
2018-03-06 16:57:55 +00:00
Sanjay Patel 62a4f5c212 [InstSimplify] remove redundant folds
The 'hasOneUse' check is a giveaway that something's not right.
We never need to check that in InstSimplify because we don't
create new instructions here.

These are all handled as icmp simplifies which then trigger
existing select simplifies, so there's no need to duplicate 
a composite fold of the two.

llvm-svn: 326750
2018-03-05 22:46:48 +00:00
Vedant Kumar 1a8456da17 Fix more spelling mistakes in comments of LLVM Analysis passes
Patch by Reshabh Sharma!

Differential Revision: https://reviews.llvm.org/D43939

llvm-svn: 326601
2018-03-02 18:57:02 +00:00
Sanjay Patel 46b083ef4a [PatternMatch, InstSimplify] fix m_NaN to work with vector constants and use it
This is NFC for the moment (and independent of any potential NaN semantic
controversy). Besides making the code in InstSimplify easier to read, the
motivation is to eventually allow undef elements in vector constants to
match too. A proposal to add the base logic for that is in D43792.

llvm-svn: 326600
2018-03-02 18:36:08 +00:00
Max Kazantsev f8d2969abb [SCEV] Smart range calculation for SCEVUnknown Phis
The range of SCEVUnknown Phi which merges values `X1, X2, ..., XN`
can be evaluated as `U(Range(X1), Range(X2), ..., Range(XN))`.

Reviewed By: sanjoy
Differential Revision: https://reviews.llvm.org/D43810

llvm-svn: 326418
2018-03-01 06:56:48 +00:00
Vedant Kumar d319674a81 Fixed spelling mistake in comments of LLVM Analysis passes
Patch by Reshabh Sharma!

Differential Revision: https://reviews.llvm.org/D43861

llvm-svn: 326352
2018-02-28 19:08:52 +00:00
David Green 7c35de124a [Dominators] Remove verifyDomTree and add some verifying for Post Dom Trees
Removes verifyDomTree, using assert(verify()) everywhere instead, and
changes verify a little to always run IsSameAsFreshTree first in order
to print good output when we find errors. Also adds verifyAnalysis for
PostDomTrees, which will allow checking of PostDomTrees it the same way
we check DomTrees and MachineDomTrees.

Differential Revision: https://reviews.llvm.org/D41298

llvm-svn: 326315
2018-02-28 11:00:08 +00:00
Craig Topper 301991080e [ValueTracking] Teach cannotBeOrderedLessThanZeroImpl to look through ExtractElement.
This is similar to what's done in computeKnownBits and computeSignBits. Don't do anything fancy just collect information valid for any element.

Differential Revision: https://reviews.llvm.org/D43789

llvm-svn: 326237
2018-02-27 19:53:45 +00:00
George Burgess IV 612cf21ec7 [MemorySSA] Call the correct dtors
It appears that there were many cases where we were directly (through
templates) calling the dtor of MemoryAccess, which is conceptually an
abstract class.

This hasn't been a problem, since the data members of all of the
subclasses of MemoryAccess have been POD. I'm planning on changing that.
:)

llvm-svn: 326175
2018-02-27 06:43:19 +00:00
Serguei Katkov 1137cde9fe [SCEV] Cleanup SCEVInitRewriter. NFC.
Set default value for IgnoreOtherLoops of SCEVInitRewriter::rewrite to true
to be consistent with SCEVPostIncRewriter which does not have this parameter
but behaves as it would be true.

This is follow up for rL326067.

llvm-svn: 326174
2018-02-27 06:39:31 +00:00
Evgeny Stupachenko a732611ac8 Fix PR36032, PR35432
Summary:

The change fix an assert fail at ScalarEvolutionExpander.cpp:
  assert(ExitCount != SE.getCouldNotCompute() && "Invalid loop count");

Reviewers: sbaranga

Differential Revision: http://reviews.llvm.org/D42604

From: Evgeny Stupachenko <evstupac@gmail.com>
                         <evgeny.v.stupachenko@intel.com>
llvm-svn: 326154
2018-02-27 00:17:31 +00:00
Craig Topper 69c8972fd1 [ValueTracking] Teach cannotBeOrderedLessThanZeroImpl to handle vector constants.
Summary: This allows vector fabs to be removed in more cases.

Reviewers: spatel, arsenm, RKSimon

Reviewed By: spatel

Subscribers: wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D43739

llvm-svn: 326138
2018-02-26 22:33:17 +00:00
Serguei Katkov c2f74638ac [SCEV] Factor out getUsedLoops
The patch introduces the new function in ScalarEvolution to get
all loops used in specified SCEV.

This is a preparation for re-writing isKnownPredicate utility as
described in https://reviews.llvm.org/D42417.

Reviewers: sanjoy, mkazantsev, reames
Reviewed By: sanjoy
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D43504

llvm-svn: 326072
2018-02-26 09:26:41 +00:00
Serguei Katkov a95d2aee7d [SCEV] Introduce SCEVPostIncRewriter
The patch introduces the SCEVPostIncRewriter rewriter which
is similar to SCEVInitRewriter but rewrites AddRec with post increment
value of this AddRec.

This is a preparation for re-writing isKnownPredicate utility as
described in https://reviews.llvm.org/D42417.

Reviewers: sanjoy, mkazantsev, reames
Reviewed By: sanjoy
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D43499

llvm-svn: 326071
2018-02-26 08:40:18 +00:00
Serguei Katkov 339c2e8287 [SCEV] Extends the SCEVInitRewriter
The patch introduces an additional parameter IgnoreOtherLoops to SCEVInitRewriter.
if it is equal to true then rewriter will not invalidate result in case
SCEV depends on other loops then specified during creation.

The patch does not change the default behavior.
This is a preparation for re-writing isKnownPredicate utility as
described in https://reviews.llvm.org/D42417.

Reviewers: sanjoy, mkazantsev, reames
Reviewed By: sanjoy
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D43498

llvm-svn: 326067
2018-02-26 07:08:56 +00:00
George Burgess IV 6f49f4a951 [MemorySSA] Remove a redundant dyn_cast.
StartingAccess is a MemoryUseOrDef. No need to check again.

llvm-svn: 326000
2018-02-24 00:15:21 +00:00
George Burgess IV 68ac941780 [MemorySSA] Fix a cache invalidation bug with removed accesses
I suspect there's a deeper issue here, but we probably shouldn't be
using INVALID_MEMORYSSA_ID as liveOnEntry's ID anyway.

llvm-svn: 325971
2018-02-23 23:07:18 +00:00
Sanjay Patel db53d1847b [InstSimplify] sqrt(X) * sqrt(X) --> X
This was misplaced in InstCombine. We can loosen the FMF as a follow-up step.

llvm-svn: 325965
2018-02-23 22:20:13 +00:00
John Brawn 29bbed3613 [BPI] Detect branches in loops that make themselves not taken
If we have a loop like this:
 int n = 0;
 while (...) {
  if (++n >= MAX) {
    n = 0;
  }
 }
then the body of the 'if' statement will only be executed once every MAX
iterations. Detect this by looking for branches in loops where taking the branch
makes the branch condition evaluate to 'not taken' in the next iteration of the
loop, and reduce the probability of such branches.

This slightly improves EEMBC benchmarks on cortex-m4/cortex-m33 due to making
better choices in if-conversion, but has no effect on any other cpu/benchmark
that I could detect.

Differential Revision: https://reviews.llvm.org/D35804

llvm-svn: 325925
2018-02-23 17:17:31 +00:00
Easwaran Raman 385d8ea8b5 [ThinLTO] Represent relative BF using a scaled representation .
Summary:
The current integer representation of relative block frequency prevents
representing relative block frequencies below 1. This change uses a 8 of
the 29 bits to represent the decimal part by using a fixed scale of -8.

Reviewers: tejohnson, davidxl

Subscribers: mehdi_amini, inglorion, llvm-commits

Differential Revision: https://reviews.llvm.org/D43520

llvm-svn: 325823
2018-02-22 19:44:08 +00:00
Max Kazantsev 80843a0acc [SCEV][NFC] Factor out common logic into a separate method
SCEV has multiple occurences of code when we need to prove some predicate on
every iteration of a loop and do it with invocations of couple `isLoopEntryGuardedByCond`,
`isLoopBackedgeGuardedByCond`. This patch factors out these two calls into a separate
method. It is a preparation step to extend this logic: it is not the only way how we can prove
such conditions.

Differential Revision: https://reviews.llvm.org/D43373

llvm-svn: 325745
2018-02-22 06:27:32 +00:00
Silviu Baranga 10ad93c6bf [SCEV] Temporarily disable loop versioning for the purpose
of turning SCEVUnknowns of PHIs into AddRecExprs.

This feature is now hidden behind the -scev-version-unknown flag.

Fixes PR36032 and PR35432.

llvm-svn: 325687
2018-02-21 15:20:32 +00:00
Benjamin Kramer fd0630665b [MemoryBuiltins] Check nobuiltin status when identifying calls to free.
This is usually not a problem because this code's main purpose is
eliminating unused new/delete pairs. We got deletes of nullptr or
nobuiltin deletes of builtin new wrong though.

llvm-svn: 325630
2018-02-20 22:00:33 +00:00
Sanjay Patel adf6e88c74 [PatternMatch, InstSimplify] enhance m_AllOnes() to ignore undef elements in vectors
Loosening the matcher definition reveals a subtle bug in InstSimplify (we should not
assume that because an operand constant matches that it's safe to return it as a result).

So I'm making that change here too (that diff could be independent, but I'm not sure how 
to reveal it before the matcher change).

This also seems like a good reason to *not* include matchers that capture the value.
We don't want to encourage the potential misstep of propagating undef values when it's
not allowed/intended.

I didn't include the capture variant option here or in the related rL325437 (m_One), 
but it already exists for other constant matchers.

llvm-svn: 325466
2018-02-18 18:05:08 +00:00
Sanjay Patel ac3952052b [InstSimplify] move select undef cond fold with other constant cond folds; NFCI
llvm-svn: 325434
2018-02-17 14:50:13 +00:00
Brian M. Rzycki f1a7df5ef2 [JumpThreading] PR36133 enable/disable DominatorTree for LVI analysis
Summary:
The LazyValueInfo pass caches a copy of the DominatorTree when available.
Whenever there are pending DominatorTree updates within JumpThreading's
DeferredDominance object we cannot use the cached DT for LVI analysis.
This commit adds the new methods enableDT() and disableDT() to LVI.
JumpThreading also sets the appropriate usage model before calling LVI
analysis methods.

Fixes https://bugs.llvm.org/show_bug.cgi?id=36133

Reviewers: sebpop, dberlin, kuhar

Reviewed by: sebpop, kuhar

Subscribers: uabelho, llvm-commits, aprantl, hiraditya, a.elovikov

Differential Revision: https://reviews.llvm.org/D42717

llvm-svn: 325356
2018-02-16 16:35:17 +00:00
Max Kazantsev fd18002990 [NFC] Rename isKnownViaSimpleReasoning to isKnownViaNonRecursiveReasoning
llvm-svn: 325216
2018-02-15 07:47:17 +00:00
Max Kazantsev c5941d12f4 [SCEV] Favor isKnownViaSimpleReasoning over constant ranges check
There is a more powerful but still simple function `isKnownViaSimpleReasoning ` that
does constant range check and few more additional checks. We use it some places (e.g.
when proving implications) and in some other places we only check constant ranges.

Currently, indvar simplifier fails to remove the check in following loop:

  int inc = ...;
  for (int i = inc, j = inc - 1; i < 200; ++i, ++j)
    if (i > j) { ... }

This patch replaces all usages of `isKnownPredicateViaConstantRanges` with
`isKnownViaSimpleReasoning` to have smarter proofs. In particular, it fixes the
case above.

Reviewed-By: sanjoy
Differential Revision: https://reviews.llvm.org/D43175

llvm-svn: 325214
2018-02-15 07:09:00 +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
Sanjay Patel 246d769232 [InstSimplify] allow exp/log simplifications with only 'reassoc' FMF
These intrinsic folds were added with D41381, but only allowed with isFast().
That's more than necessary because FMF has 'reassoc' to apply to these
kinds of folds after D39304, and that's all we need in these cases.

Differential Revision: https://reviews.llvm.org/D43160

llvm-svn: 324967
2018-02-12 23:51:23 +00:00
Max Kazantsev db3a9e0cfe [SCEV] Make getPostIncExpr guaranteed to return AddRec
The current implementation of `getPostIncExpr` invokes `getAddExpr` for two recurrencies
and expects that it always returns it a recurrency. But this is not guaranteed to happen if we
have reached max recursion depth or refused to make SCEV simplification for other reasons.

This patch changes its implementation so that now it always returns SCEVAddRec without
relying on `getAddExpr`.

Differential Revision: https://reviews.llvm.org/D42953

llvm-svn: 324866
2018-02-12 05:09:38 +00:00
Sanjay Patel a60aec1ab7 [ValueTracking] don't crash when assumptions conflict (PR36270)
The last assume in the test says that %B12 is 0. 
The first assume says that %and1 is less than %B12. 
Therefore, %and1 is unsigned less than 0...does not compute.

That means this line:
Known.Zero.setHighBits(RHSKnown.countMinLeadingZeros() + 1);
...tries to set more bits than exist.

Differential Revision: https://reviews.llvm.org/D43052

llvm-svn: 324610
2018-02-08 14:52:40 +00:00
Max Kazantsev b299ade2c5 Re-enable "[SCEV] Make isLoopEntryGuardedByCond a bit smarter"
The failures happened because of assert which was overconfident about
SCEV's proving capabilities and is generally not valid.

Differential Revision: https://reviews.llvm.org/D42835

llvm-svn: 324473
2018-02-07 11:16:29 +00:00
Serguei Katkov 69246ca787 Revert [SCEV] Make isLoopEntryGuardedByCond a bit smarter
Revert rL324453 commit which causes buildbot failures.

Differential Revision: https://reviews.llvm.org/D42835

llvm-svn: 324462
2018-02-07 09:10:08 +00:00
Max Kazantsev dd5ee6f5d9 [SCEV] Make isLoopEntryGuardedByCond a bit smarter
Sometimes `isLoopEntryGuardedByCond` cannot prove predicate `a > b` directly.
But it is a common situation when `a >= b` is known from ranges and `a != b` is
known from a dominating condition. Thia patch teaches SCEV to sum these facts
together and prove strict comparison via non-strict one.

Differential Revision: https://reviews.llvm.org/D42835

llvm-svn: 324453
2018-02-07 07:56:26 +00:00
Michael Zolotukhin e82e83fcce Follow-up for r324429: "[LCSSAVerification] Run verification only when asserts are enabled."
Before r324429 we essentially didn't have a verification of LCSSA, so
no wonder that it has been broken: currently loop-sink breaks it (the
attached test illustrates the failure).

It was detected during a stage2 RA build, so to unbreak it I'm disabling
the check for now.

llvm-svn: 324445
2018-02-07 04:24:44 +00:00
Michael Zolotukhin ec8b0ecaab [LCSSAVerification] Run verification only when asserts are enabled.
llvm-svn: 324429
2018-02-07 00:13:08 +00:00
Simon Pilgrim 9f2ae7e2d1 [InstCombine][ValueTracking] Match non-uniform constant power-of-two vectors
Generalize existing constant matching to work with non-uniform constant vectors as well.

Differential Revision: https://reviews.llvm.org/D42818

llvm-svn: 324369
2018-02-06 18:39:23 +00:00
Sanjay Patel d7c702b451 [LoopStrengthReduce, x86] don't add cost for a cmp that will be macro-fused (PR35681)
In the motivating case from PR35681 and represented by the macro-fuse-cmp test:
https://bugs.llvm.org/show_bug.cgi?id=35681
...there's a 37 -> 31 byte size win for the loop because we eliminate the big base 
address offsets.

SPEC2017 on Ryzen shows no significant perf difference.

Differential Revision: https://reviews.llvm.org/D42607

llvm-svn: 324289
2018-02-05 23:43:05 +00:00
Serguei Katkov ec7029c286 Re-apply [SCEV] Fix isLoopEntryGuardedByCond usage
ScalarEvolution::isKnownPredicate invokes isLoopEntryGuardedByCond without check
that SCEV is available at entry point of the loop. It is incorrect and fixed by patch.

To bugs additionally fixed:
assert is moved after the check whether loop is not a nullptr.
Usage of isLoopEntryGuardedByCond in ScalarEvolution::isImpliedCondOperandsViaNoOverflow
is guarded by isAvailableAtLoopEntry.

Reviewers: sanjoy, mkazantsev, anna, dorit, reames
Reviewed By: mkazantsev
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D42417

llvm-svn: 324204
2018-02-05 05:49:47 +00:00
Ivan A. Kosarev ab68bbe515 [Analysis] Support aggregate access types in TBAA
This patch implements analysis for new-format TBAA access tags
with aggregate types as their final access types.

Differential Revision: https://reviews.llvm.org/D41501

llvm-svn: 324092
2018-02-02 14:09:22 +00:00
Easwaran Raman 06a715333a Remove CallGraphTraits and use equivalent methods in GraphTraits
Summary:
D42698 adds child_edge_{begin|end} and children_edges to GraphTraits
which are used here. The reason for this change is to make it easy to
use count propagation on ModulesummaryIndex. As it stands,
CallGraphTraits is in Analysis while ModuleSummaryIndex is in IR.

Reviewers: davidxl, dberlin

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D42703

llvm-svn: 323994
2018-02-01 19:40:35 +00:00
Chih-Hung Hsieh 60d1e79ffb [Analysis] Disable calls to *_finite and other glibc-only functions on Android.
Since r322087, glibc's finite lib calls are generated when possible.
However, they are not supported on Android. This change also
disables other functions not available on Android.

Differential Revision: http://reviews.llvm.org/D42668

llvm-svn: 323898
2018-01-31 19:12:50 +00:00
Daniel Neilson 147810d28a [Lint] Upgrade uses of MemoryIntrinic::getAlignment() to new API. (NFCI)
Summary:
  This change is part of step five in the series of changes to remove alignment argument from
memcpy/memmove/memset in favour of alignment attributes. In particular, this changes the Lint
analysis to cease using the old getAlignment() API of MemoryIntrinsic in favour of getting
source & dest specific alignments through the new API.

Steps:
Step 1) Remove alignment parameter and create alignment parameter attributes for
memcpy/memmove/memset. ( rL322965, rC322964, rL322963 )
Step 2) Expand the IRBuilder API to allow creation of memcpy/memmove with differing
source and dest alignments. ( rL323597 )
Step 3) Update Clang to use the new IRBuilder API. ( rC323617 )
Step 4) Update Polly to use the new IRBuilder API. ( rL323618 )
Step 5) Update LLVM passes that create memcpy/memmove calls to use the new IRBuilder API,
and those that use use MemIntrinsicInst::[get|set]Alignment() to use [get|set]DestAlignment()
and [get|set]SourceAlignment() instead.
Step 6) Remove the single-alignment IRBuilder API for memcpy/memmove, and the
MemIntrinsicInst::[get|set]Alignment() methods.

Reference
   http://lists.llvm.org/pipermail/llvm-dev/2015-August/089384.html
   http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20151109/312083.html

llvm-svn: 323886
2018-01-31 16:42:15 +00:00
Zaara Syeda 1f59ae311b Re-commit : [PowerPC] Add handling for ColdCC calling convention and a pass to mark
candidates with coldcc attribute.

This recommits r322721 reverted due to sanitizer memory leak build bot failures.

Original commit message:
This patch adds support for the coldcc calling convention for Power.
This changes the set of non-volatile registers. It includes a pass to stress
test the implementation by marking all static directly called functions with
the coldcc attribute through the option -enable-coldcc-stress-test. It also
includes an option, -ppc-enable-coldcc, to add the coldcc attribute to
functions which are cold at all call sites based on BlockFrequencyInfo when
the containing function does not call any non cold functions.

Differential Revision: https://reviews.llvm.org/D38413

llvm-svn: 323778
2018-01-30 16:17:22 +00:00
Sanjay Patel 83f056604c [InstSimplify] (X * Y) / Y --> X for relaxed floating-point ops
This is the FP counterpart that was mentioned in PR35709:
https://bugs.llvm.org/show_bug.cgi?id=35709

Differential Revision: https://reviews.llvm.org/D42385

llvm-svn: 323716
2018-01-30 00:18:37 +00:00