Commit Graph

32 Commits

Author SHA1 Message Date
Sanjoy Das a5397c0198 [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

llvm-svn: 231306
2015-03-04 22:24:23 +00:00
Chandler Carruth 24fd029a60 [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!).

llvm-svn: 226376
2015-01-17 14:31:35 +00:00
Chandler Carruth 4f8f307c77 [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.

llvm-svn: 226373
2015-01-17 14:16:18 +00:00
David Majnemer f0982d0ac6 SimplifyIndVar: Remove unused variable
OtherOperandIdx is not used anymore, remove it to silence warnings.

llvm-svn: 226138
2015-01-15 07:11:23 +00:00
Sanjoy Das 8c252bde36 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

llvm-svn: 226075
2015-01-15 01:46:09 +00:00
Sanjoy Das 7c0ce26614 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

llvm-svn: 225282
2015-01-06 19:02:56 +00:00
David Blaikie 70573dcd9f 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...

llvm-svn: 222334
2014-11-19 07:49:26 +00:00
Sanjay Patel 7777b50eaf remove function names from comments; NFC
llvm-svn: 221798
2014-11-12 18:07:42 +00:00
Craig Topper f40110f4d8 [C++] Use 'nullptr'. Transforms edition.
llvm-svn: 207196
2014-04-25 05:29:35 +00:00
Chandler Carruth 964daaaf19 [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.

llvm-svn: 206844
2014-04-22 02:55:47 +00:00
Chandler Carruth cdf4788401 [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. =]

llvm-svn: 203364
2014-03-09 03:16:01 +00:00
Benjamin Kramer b6d0bd48bd [C++11] Replace llvm::next and llvm::prior with std::next and std::prev.
Remove the old functions.

llvm-svn: 202636
2014-03-02 12:27:27 +00:00
Rafael Espindola 935125126c 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.

llvm-svn: 202168
2014-02-25 17:30:31 +00:00
Rafael Espindola 37dc9e19f5 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.

llvm-svn: 201827
2014-02-21 00:06:31 +00:00
Chandler Carruth 5ad5f15cff [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.

llvm-svn: 199082
2014-01-13 09:26:24 +00:00
Chandler Carruth 8a8cd2bab9 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.

llvm-svn: 198685
2014-01-07 11:48:04 +00:00
Andrew Trick 0ba77a0740 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.

llvm-svn: 197926
2013-12-23 23:31:49 +00:00
Benjamin Kramer fc3ea6f4bc Don't use a potentially expensive shift if all we want is one set bit.
No functionality change.

llvm-svn: 186095
2013-07-11 16:05:50 +00:00
Chandler Carruth 9fb823bbd4 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.

llvm-svn: 171366
2013-01-02 11:36:10 +00:00
Chandler Carruth ed0881b2a6 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. =]

llvm-svn: 169131
2012-12-03 16:50:05 +00:00
Micah Villmow cdfe20b97f Move TargetData to DataLayout.
llvm-svn: 165402
2012-10-08 16:38:25 +00:00
Benjamin Kramer 628a39faa3 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.

llvm-svn: 158090
2012-06-06 18:25:08 +00:00
Andrew Trick 0654989062 Remove unused simplifyIVUsers
llvm-svn: 153262
2012-03-22 17:47:30 +00:00
Andrew Trick 070e540a3e 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

llvm-svn: 152892
2012-03-16 03:16:56 +00:00
David Blaikie a379b18173 Unweaken vtables as per http://llvm.org/docs/CodingStandards.html#ll_virtual_anch
llvm-svn: 146960
2011-12-20 02:50:00 +00:00
Andrew Trick 949045864d 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.

llvm-svn: 144935
2011-11-17 23:36:35 +00:00
Benjamin Kramer 547b6c5ecd 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.

llvm-svn: 140634
2011-09-27 20:39:19 +00:00
Andrew Trick 7251e41b16 [indvars] Fix PR10946: SCEV cannot handle Vector IVs.
llvm-svn: 140026
2011-09-19 17:54:39 +00:00
Andrew Trick 6dbb060778 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.

llvm-svn: 137229
2011-08-10 18:07:05 +00:00
Andrew Trick e629d008fb Cleanup. Make ScalarEvolution an explicit argument of the
SimplifyIndVar utility since it is required.

llvm-svn: 137202
2011-08-10 04:22:26 +00:00
Andrew Trick 74664d5ec6 SimplifyIndVar: make foldIVUser iterative to fold a chain of operands.
llvm-svn: 137199
2011-08-10 04:01:31 +00:00
Andrew Trick 3ec331eaf4 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.

llvm-svn: 137197
2011-08-10 03:46:27 +00:00