43 Commits

Author SHA1 Message Date
Sanjoy Das
d23e55c402 [IndVars] Preserve LCSSA in eliminateIdentitySCEV
Summary:
After r249211, SCEV can see through some LCSSA phis.  Add a
`replacementPreservesLCSSAForm` check before replacing uses of these phi
nodes with a simplified use of the induction variable to avoid breaking
LCSSA.

Fixes 25047.

Depends on D13460.

Reviewers: atrick, hfinkel

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D13461

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249575 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-07 17:38:31 +00:00
Sanjoy Das
d15cdb7b13 [IndVars] Don't break dominance in eliminateIdentitySCEV
Summary:
After r249211, `getSCEV(X) == getSCEV(Y)` does not guarantee that X and
Y are related in the dominator tree, even if X is an operand to Y (I've
included a toy example in comments, and a real example as a test case).

This commit changes `SimplifyIndVar` to require a `DominatorTree`.  I
don't think this is a problem because `ScalarEvolution` requires it
anyway.

Fixes PR25051.

Depends on D13459.

Reviewers: atrick, hfinkel

Subscribers: joker.eph, llvm-commits, sanjoy

Differential Revision: http://reviews.llvm.org/D13460

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249471 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-06 21:44:49 +00:00
Sanjoy Das
3692363a2c [IndVars] Extract out eliminateIdentitySCEV, NFC
Summary:
Reflow a comment while at it.

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D13459

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249470 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-06 21:44:39 +00:00
Sanjoy Das
6d6e2b5a35 [SCEV] Introduce ScalarEvolution::getOne and getZero.
Summary:
It is fairly common to call SE->getConstant(Ty, 0) or
SE->getConstant(Ty, 1); this change makes such uses a little bit
briefer.

I've refactored the call sites I could find easily to use getZero /
getOne.

Reviewers: hfinkel, majnemer, reames

Subscribers: sanjoy, llvm-commits

Differential Revision: http://reviews.llvm.org/D12947

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@248362 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-23 01:59:04 +00:00
Benjamin Kramer
d3c712e50b Fix some comment typos.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@244402 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-08 18:27:36 +00:00
Sanjoy Das
95d9915c5c [IndVars] Improved logging under DEBUG(); NFC.
Before this, we'd print the modified comparision in the "Simplified
comparison" case.  That looked misleading.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@244264 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-06 20:43:28 +00:00
Sanjoy Das
39d6da003d [IndVars] Make loop varying predicates loop invariant.
Summary:
Was D9784: "Remove loop variant range check when induction variable is
strictly increasing"

This change re-implements D9784 with the two differences:

 1. It does not use SCEVExpander and does not generate new
    instructions.  Instead, it does a quick local search for existing
    `llvm::Value`s that it needs when modifying the `icmp`
    instruction.

 2. It is more general -- it deals with both increasing and decreasing
    induction variables.

I've added all of the tests included with D9784, and two more.

As an example on what this change does (copied from D9784):

Given C code:

```
for (int i = M; i < N; i++) // i is known not to overflow
  if (i < 0) break;
  a[i] = 0;
}
```

This transformation produces:

```
for (int i = M; i < N; i++)
  if (M < 0) break;
  a[i] = 0;
}
```

Which can be unswitched into:

```
if (!(M < 0))
  for (int i = M; i < N; i++)
    a[i] = 0;
}
```

I went back and forth on whether the top level logic should live in
`SimplifyIndvar::eliminateIVComparison` or be put into its own
routine.  Right now I've put it under `eliminateIVComparison` because
even though the `icmp` is not *eliminated*, it no longer is an IV
comparison.  I'm open to putting it in its own helper routine if you
think that is better.

Reviewers: reames, nicholas, atrick

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D11278

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@243331 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-27 21:42:49 +00:00
Alexander Kornienko
cd52a7a381 Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC)
Apparently, the style needs to be agreed upon first.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240390 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-23 09:49:53 +00:00
Alexander Kornienko
cf0db29df2 Fixed/added namespace ending comments using clang-tidy. NFC
The patch is generated using this command:

tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
  -checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
  llvm/lib/


Thanks to Eugene Kosov for the original patch!



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240137 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-19 15:57:42 +00:00
Benjamin Kramer
9589ff8949 Replace push_back(Constructor(foo)) with emplace_back(foo) for non-trivial types
If the type isn't trivially moveable emplace can skip a potentially
expensive move. It also saves a couple of characters.


Call sites were found with the ASTMatcher + some semi-automated cleanup.

memberCallExpr(
    argumentCountIs(1), callee(methodDecl(hasName("push_back"))),
    on(hasType(recordDecl(has(namedDecl(hasName("emplace_back")))))),
    hasArgument(0, bindTemporaryExpr(
                       hasType(recordDecl(hasNonTrivialDestructor())),
                       has(constructExpr()))),
    unless(isInTemplateInstantiation()))

No functional change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238602 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-29 19:43:39 +00:00
Andrew Trick
688ae334a3 SimplifyIV comments and dead argument cleanup.
Remove crufty comments. IVUsers hasn't been used here for a long time.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237586 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-18 16:49:31 +00:00
Sanjoy Das
295be8492e [IndVarSimplify] use the "canonical" way to infer no-wrap.
Summary:
rL225282 introduced an ad-hoc way to promote some additions to nuw or
nsw.  Since then SCEV has become smarter in directly proving no-wrap;
and using the canonical "ext(A op B) == ext(A) op ext(B)" method of
proving no-wrap is just as powerful now.  Rip out the existing
complexity in favor of getting SCEV to do all the heaving lifting
internally.

This change does not add any unit tests because it is supposed to be a
non-functional change.  Tests added in rL225282 and rL226075 are valid
tests for this change.

Reviewers: atrick, majnemer

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D7981

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231306 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-04 22:24:23 +00:00
Chandler Carruth
122e67cb34 [PM] Remove a dead field.
This was dead even before I refactored how we initialized it, but my
refactoring made it trivially dead and it is now caught by a Clang
warning. This fixes the warning and should clean up the -Werror bot
failures (sorry!).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226376 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-17 14:31:35 +00:00
Chandler Carruth
de5df29556 [PM] Split the LoopInfo object apart from the legacy pass, creating
a LoopInfoWrapperPass to wire the object up to the legacy pass manager.

This switches all the clients of LoopInfo over and paves the way to port
LoopInfo to the new pass manager. No functionality change is intended
with this iteration.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226373 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-17 14:16:18 +00:00
David Majnemer
cdfb69b2a3 SimplifyIndVar: Remove unused variable
OtherOperandIdx is not used anymore, remove it to silence warnings.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226138 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-15 07:11:23 +00:00
Sanjoy Das
7ec1829823 Fix PR22222
The bug was introduced in r225282. r225282 assumed that sub X, Y is
the same as add X, -Y. This is not correct if we are going to upgrade
the sub to sub nuw. This change fixes the issue by making the
optimization ignore sub instructions.

Differential Revision: http://reviews.llvm.org/D6979



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226075 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-15 01:46:09 +00:00
Sanjoy Das
31123d4529 This patch teaches IndVarSimplify to add nuw and nsw to certain kinds
of operations that provably don't overflow. For example, we can prove
%civ.inc below does not sign-overflow. With this change,
IndVarSimplify changes %civ.inc to an add nsw.

  define i32 @foo(i32* %array, i32* %length_ptr, i32 %init) {
   entry:
    %length = load i32* %length_ptr, !range !0
    %len.sub.1 = sub i32 %length, 1
    %upper = icmp slt i32 %init, %len.sub.1
    br i1 %upper, label %loop, label %exit
  
   loop:
    %civ = phi i32 [ %init, %entry ], [ %civ.inc, %latch ]
    %civ.inc = add i32 %civ, 1
    %cmp = icmp slt i32 %civ.inc, %length
    br i1 %cmp, label %latch, label %break
  
   latch:
    store i32 0, i32* %array
    %check = icmp slt i32 %civ.inc, %len.sub.1
    br i1 %check, label %loop, label %break
  
   break:
    ret i32 %civ.inc
  
   exit:
    ret i32 42
  }

Differential Revision: http://reviews.llvm.org/D6748



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225282 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-06 19:02:56 +00:00
David Blaikie
5401ba7099 Update SetVector to rely on the underlying set's insert to return a pair<iterator, bool>
This is to be consistent with StringSet and ultimately with the standard
library's associative container insert function.

This lead to updating SmallSet::insert to return pair<iterator, bool>,
and then to update SmallPtrSet::insert to return pair<iterator, bool>,
and then to update all the existing users of those functions...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222334 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-19 07:49:26 +00:00
Sanjay Patel
04a3fdf788 remove function names from comments; NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221798 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 18:07:42 +00:00
Craig Topper
8d7221ccf5 [C++] Use 'nullptr'. Transforms edition.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207196 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-25 05:29:35 +00:00
Chandler Carruth
7962dbdc65 [Modules] Fix potential ODR violations by sinking the DEBUG_TYPE
definition below all of the header #include lines, lib/Transforms/...
edition.

This one is tricky for two reasons. We again have a couple of passes
that define something else before the includes as well. I've sunk their
name macros with the DEBUG_TYPE.

Also, InstCombine contains headers that need DEBUG_TYPE, so now those
headers #define and #undef DEBUG_TYPE around their code, leaving them
well formed modular headers. Fixing these headers was a large motivation
for all of these changes, as "leaky" macros of this form are hard on the
modules implementation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206844 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-22 02:55:47 +00:00
Chandler Carruth
36b699f2b1 [C++11] Add range based accessors for the Use-Def chain of a Value.
This requires a number of steps.
1) Move value_use_iterator into the Value class as an implementation
   detail
2) Change it to actually be a *Use* iterator rather than a *User*
   iterator.
3) Add an adaptor which is a User iterator that always looks through the
   Use to the User.
4) Wrap these in Value::use_iterator and Value::user_iterator typedefs.
5) Add the range adaptors as Value::uses() and Value::users().
6) Update *all* of the callers to correctly distinguish between whether
   they wanted a use_iterator (and to explicitly dig out the User when
   needed), or a user_iterator which makes the Use itself totally
   opaque.

Because #6 requires churning essentially everything that walked the
Use-Def chains, I went ahead and added all of the range adaptors and
switched them to range-based loops where appropriate. Also because the
renaming requires at least churning every line of code, it didn't make
any sense to split these up into multiple commits -- all of which would
touch all of the same lies of code.

The result is still not quite optimal. The Value::use_iterator is a nice
regular iterator, but Value::user_iterator is an iterator over User*s
rather than over the User objects themselves. As a consequence, it fits
a bit awkwardly into the range-based world and it has the weird
extra-dereferencing 'operator->' that so many of our iterators have.
I think this could be fixed by providing something which transforms
a range of T&s into a range of T*s, but that *can* be separated into
another patch, and it isn't yet 100% clear whether this is the right
move.

However, this change gets us most of the benefit and cleans up
a substantial amount of code around Use and User. =]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203364 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-09 03:16:01 +00:00
Benjamin Kramer
d628f19f5d [C++11] Replace llvm::next and llvm::prior with std::next and std::prev.
Remove the old functions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202636 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-02 12:27:27 +00:00
Rafael Espindola
57edc9d4ff Make DataLayout a plain object, not a pass.
Instead, have a DataLayoutPass that holds one. This will allow parts of LLVM
don't don't handle passes to also use DataLayout.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202168 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-25 17:30:31 +00:00
Rafael Espindola
f116e5308d Rename many DataLayout variables from TD to DL.
I am really sorry for the noise, but the current state where some parts of the
code use TD (from the old name: TargetData) and other parts use DL makes it
hard to write a patch that changes where those variables come from and how
they are passed along.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201827 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-21 00:06:31 +00:00
Chandler Carruth
56e1394c88 [cleanup] Move the Dominators.h and Verifier.h headers into the IR
directory. These passes are already defined in the IR library, and it
doesn't make any sense to have the headers in Analysis.

Long term, I think there is going to be a much better way to divide
these matters. The dominators code should be fully separated into the
abstract graph algorithm and have that put in Support where it becomes
obvious that evn Clang's CFGBlock's can use it. Then the verifier can
manually construct dominance information from the Support-driven
interface while the Analysis library can provide a pass which both
caches, reconstructs, and supports a nice update API.

But those are very long term, and so I don't want to leave the really
confusing structure until that day arrives.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199082 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-13 09:26:24 +00:00
Chandler Carruth
974a445bd9 Re-sort all of the includes with ./utils/sort_includes.py so that
subsequent changes are easier to review. About to fix some layering
issues, and wanted to separate out the necessary churn.

Also comment and sink the include of "Windows.h" in three .inc files to
match the usage in Memory.inc.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198685 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-07 11:48:04 +00:00
Andrew Trick
c7b0b7dc8f Add support to indvars for optimizing sadd.with.overflow.
Split sadd.with.overflow into add + sadd.with.overflow to allow
analysis and optimization. This should ideally be done after
InstCombine, which can perform code motion (eventually indvars should
run after all canonical instcombines). We want ISEL to recombine the
add and the check, at least on x86.

This is currently under an option for reducing live induction
variables: -liv-reduce. The next step is reducing liveness of IVs that
are live out of the overflow check paths. Once the related
optimizations are fully developed, reviewed and tested, I do expect
this to become default.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@197926 91177308-0d34-0410-b5e6-96231b3b80d8
2013-12-23 23:31:49 +00:00
Benjamin Kramer
0a230e0d98 Don't use a potentially expensive shift if all we want is one set bit.
No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186095 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-11 16:05:50 +00:00
Chandler Carruth
0b8c9a80f2 Move all of the header files which are involved in modelling the LLVM IR
into their new header subdirectory: include/llvm/IR. This matches the
directory structure of lib, and begins to correct a long standing point
of file layout clutter in LLVM.

There are still more header files to move here, but I wanted to handle
them in separate commits to make tracking what files make sense at each
layer easier.

The only really questionable files here are the target intrinsic
tablegen files. But that's a battle I'd rather not fight today.

I've updated both CMake and Makefile build systems (I think, and my
tests think, but I may have missed something).

I've also re-sorted the includes throughout the project. I'll be
committing updates to Clang, DragonEgg, and Polly momentarily.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171366 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-02 11:36:10 +00:00
Chandler Carruth
d04a8d4b33 Use the new script to sort the includes of every file under lib.
Sooooo many of these had incorrect or strange main module includes.
I have manually inspected all of these, and fixed the main module
include to be the nearest plausible thing I could find. If you own or
care about any of these source files, I encourage you to take some time
and check that these edits were sensible. I can't have broken anything
(I strictly added headers, and reordered them, never removed), but they
may not be the headers you'd really like to identify as containing the
API being implemented.

Many forward declarations and missing includes were added to a header
files to allow them to parse cleanly when included first. The main
module rule does in fact have its merits. =]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169131 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-03 16:50:05 +00:00
Micah Villmow
3574eca1b0 Move TargetData to DataLayout.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165402 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-08 16:38:25 +00:00
Benjamin Kramer
a7542d5f87 Remove unused private fields found by clang's new -Wunused-private-field.
There are some that I didn't remove this round because they looked like
obvious stubs. There are dead variables in gtest too, they should be
fixed upstream.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158090 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-06 18:25:08 +00:00
Andrew Trick
9f2539507c Remove unused simplifyIVUsers
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153262 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-22 17:47:30 +00:00
Andrew Trick
75ae20366f LSR fix: Add isSimplifiedLoopNest to IVUsers analysis.
Only record IVUsers that are dominated by simplified loop
headers. Otherwise SCEVExpander will crash while looking for a
preheader.

I previously tried to work around this in LSR itself, but that was
insufficient. This way, LSR can continue to run if some uses are not
in simple loops, as long as we don't attempt to analyze those users.

Fixes <rdar://problem/11049788> Segmentation fault: 11 in LoopStrengthReduce

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152892 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-16 03:16:56 +00:00
David Blaikie
2d24e2a396 Unweaken vtables as per http://llvm.org/docs/CodingStandards.html#ll_virtual_anch
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146960 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-20 02:50:00 +00:00
Andrew Trick
4f3052403c Fix an overly general check in SimplifyIndvar to handle useless phi cycles.
The right way to check for a binary operation is
cast<BinaryOperator>. The original check: cast<Instruction> &&
numOperands() == 2 would match phi "instructions", leading to an
infinite loop in extreme corner case: a useless phi with operands
[self, constant] that prior optimization passes failed to remove,
being used in the loop by another useless phi, in turn being used by an
lshr or udiv.

Fixes PR11350: runaway iteration assertion.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144935 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-17 23:36:35 +00:00
Benjamin Kramer
a9390a4d5f Stop emitting instructions with the name "tmp" they eat up memory and have to be uniqued, without any benefit.
If someone prefers %tmp42 to %42, run instnamer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@140634 91177308-0d34-0410-b5e6-96231b3b80d8
2011-09-27 20:39:19 +00:00
Andrew Trick
24f48ece52 [indvars] Fix PR10946: SCEV cannot handle Vector IVs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@140026 91177308-0d34-0410-b5e6-96231b3b80d8
2011-09-19 17:54:39 +00:00
Andrew Trick
7cb3dcb927 Comments. Thanks for the spell check Nick!
Also, my apologies for spoiling the autocomplete on SimplifyInstructions.cpp. I couldn't think of a better filename.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137229 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-10 18:07:05 +00:00
Andrew Trick
bddb7f8210 Cleanup. Make ScalarEvolution an explicit argument of the
SimplifyIndVar utility since it is required.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137202 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-10 04:22:26 +00:00
Andrew Trick
ea23daa446 SimplifyIndVar: make foldIVUser iterative to fold a chain of operands.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137199 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-10 04:01:31 +00:00
Andrew Trick
4b4bb71bcd Added a SimplifyIndVar utility to simplify induction variable users
based on ScalarEvolution without changing the induction variable phis.

This utility is the main tool of IndVarSimplifyPass, but the pass also
restructures induction variables in strange ways that are sensitive to
pass ordering. This provides a way for other loop passes to simplify
new uses of induction variables created during transformation. The
utility may be used by any pass that preserves ScalarEvolution. Soon
LoopUnroll will use it.

The net effect in this checkin is to cleanup the IndVarSimplify pass
by factoring out the SimplifyIndVar algorithm into a standalone utility.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137197 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-10 03:46:27 +00:00