237 Commits

Author SHA1 Message Date
Chad Rosier
e53e8c8e58 [Reassociate] Rename local variable to not use same name as a member
variable. NFC.

llvm-svn: 222248
2014-11-18 20:21:54 +00:00
Chad Rosier
bc0b869be9 [Reassociate] As the expression tree is rewritten make sure the operands are
emitted in canonical form.

llvm-svn: 222142
2014-11-17 16:33:50 +00:00
Chad Rosier
9a1ac6e494 [Reassociate] Canonicalize constants to RHS operand.
Fix a thinko where the RHS was already a constant.

llvm-svn: 222139
2014-11-17 15:52:51 +00:00
Chad Rosier
df8f2a23cb [Reassociate] Canonicalize the operands of all binary operators.
llvm-svn: 222008
2014-11-14 17:09:19 +00:00
Chad Rosier
d99df68e19 [Reassociate] Canonicalize operands of vector binary operators.
Prior to this commit fmul and fadd binary operators were being canonicalized for
both scalar and vector versions.  We now canonicalize add, mul, and, or, and xor
vector instructions.

llvm-svn: 222006
2014-11-14 17:08:15 +00:00
Chad Rosier
f8b55f1bc5 [Reassociate] Canonicalize constants to RHS operand.
llvm-svn: 222005
2014-11-14 17:05:59 +00:00
Chad Rosier
f59e548ba7 [Reassociate] Improve rank debug information. NFC.
llvm-svn: 221999
2014-11-14 15:01:38 +00:00
Chad Rosier
9074b18785 [Reassociate] Update comment. NFC.
llvm-svn: 221894
2014-11-13 15:40:20 +00:00
Chad Rosier
f53f07046b [Reassociate] Canonicalize negative constants out of expressions.
Add support for FDiv, which was regressed by the previous commit.

llvm-svn: 221738
2014-11-11 23:36:42 +00:00
Chad Rosier
094ac7735b [Reassociate] Canonicalize negative constants out of expressions.
This is a reapplication of r221171, but we only perform the transformation
on expressions which include a multiplication.  We do not transform rem/div
operations as this doesn't appear to be safe in all cases.

llvm-svn: 221721
2014-11-11 22:58:35 +00:00
Chad Rosier
b3eb452e83 [Reassociate] Better preserve NSW/NUW flags.
Part of PR12985.

Phabricator Revision: http://reviews.llvm.org/D6172

llvm-svn: 221555
2014-11-07 22:12:57 +00:00
Chad Rosier
ac6a2f532c [Reassociate] Don't reassociate when mixing regular and fast-math FP
instructions.  Inlining might cause such cases and it's not valid to
reassociate floating-point instructions without the unsafe algebra flag.

Patch by Mehdi Amini <mehdi_amini@apple.com>!

llvm-svn: 221462
2014-11-06 16:46:37 +00:00
Reid Kleckner
941e93e9a8 Revert "[Reassociate] Canonicalize negative constants out of expressions."
This reverts commit r221171.

It performs this invalid transformation:
-  %div.i = urem i64 -1, %add
-  %sub.i = sub i64 -2, %div.i
+  %div.i = urem i64 1, %add
+  %sub.i1 = add i64 %div.i, -2

llvm-svn: 221317
2014-11-04 23:42:45 +00:00
Chad Rosier
005505b027 [Reassociate] Canonicalize negative constants out of expressions.
This gives CSE/GVN more options to eliminate duplicate expressions.
This is a follow up patch to http://reviews.llvm.org/D4904.

http://reviews.llvm.org/D5363

llvm-svn: 221171
2014-11-03 19:11:30 +00:00
Chad Rosier
bd64d46188 [Reassociate] Don't canonicalize X - undef to X + (-undef).
Phabricator Revision: http://reviews.llvm.org/D5674
PR21205

llvm-svn: 219434
2014-10-09 20:06:29 +00:00
Owen Anderson
8373d338f6 Give the Reassociate pass a bit more flexibility and autonomy when optimizing expressions.
Particularly, it addresses cases where Reassociate breaks Subtracts but then fails to optimize combinations like I1 + -I2 where I1 and I2 have the same rank and are identical.

Patch by Dmitri Shtilman.

llvm-svn: 219092
2014-10-05 23:41:26 +00:00
Erik Verbruggen
2b98bd2a80 Reassociate x + -0.1234 * y into x - 0.1234 * y
This does not require -ffast-math, and it gives CSE/GVN more options to
eliminate duplicate expressions in, e.g.:

  return ((x + 0.1234 * y) * (x - 0.1234 * y));

Differential Revision: http://reviews.llvm.org/D4904

llvm-svn: 216169
2014-08-21 10:45:30 +00:00
Chad Rosier
11ab941644 [Reassociation] Add support for reassociation with unsafe algebra.
Vector instructions are (still) not supported for either integer or floating
point.  Hopefully, that work will be landed shortly.

llvm-svn: 215647
2014-08-14 15:23:01 +00:00
Benjamin Kramer
4968944376 [Reassociate] Similar to "X + -X" -> "0", added code to handle "X + ~X" -> "-1".
Handle "X + ~X" -> "-1" in the function Value *Reassociate::OptimizeAdd(Instruction *I, SmallVectorImpl<ValueEntry> &Ops);
This patch implements:
TODO: We could handle "X + ~X" -> "-1" if we wanted, since "-X = ~X+1".

Patch by Rahul Jain!

Differential Revision: http://reviews.llvm.org/D3835

llvm-svn: 209973
2014-05-31 15:01:54 +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
Craig Topper
3e4c697ca1 [C++11] Add 'override' keyword to virtual methods that override their base class.
llvm-svn: 202953
2014-03-05 09:10:37 +00:00
Chandler Carruth
1305dc3351 [Modules] Move CFG.h to the IR library as it defines graph traits over
IR types.

llvm-svn: 202827
2014-03-04 11:45:46 +00:00
Chandler Carruth
4220e9c154 [Modules] Move ValueHandle into the IR library where Value itself lives.
Move the test for this class into the IR unittests as well.

This uncovers that ValueMap too is in the IR library. Ironically, the
unittest for ValueMap is useless in the Support library (honestly, so
was the ValueHandle test) and so it already lives in the IR unittests.
Mmmm, tasty layering.

llvm-svn: 202821
2014-03-04 11:17:44 +00:00
Benjamin Kramer
3a377bce4e Now that we have C++11, turn simple functors into lambdas and remove a ton of boilerplate.
No intended functionality change.

llvm-svn: 202588
2014-03-01 11:47:00 +00:00
Chandler Carruth
7b8e112407 [reassociate] Switch two std::sort calls into std::stable_sort calls as
their inputs come from std::stable_sort and they are not total orders.

I'm not a huge fan of this, but the really bad std::stable_sort is right
at the beginning of Reassociate. After we commit to stable-sort based
consistent respect of source order, the downstream sorts shouldn't undo
that unless they have a total order or they are used in an
order-insensitive way. Neither appears to be true for these cases.
I don't have particularly good test cases, but this jumped out by
inspection when looking for output instability in this pass due to
changes in the ordering of std::sort.

llvm-svn: 202196
2014-02-25 21:54:50 +00:00
Paul Robinson
af4e64d095 Disable most IR-level transform passes on functions marked 'optnone'.
Ideally only those transform passes that run at -O0 remain enabled,
in reality we get as close as we reasonably can.
Passes are responsible for disabling themselves, it's not the job of
the pass manager to do it for them.

llvm-svn: 200892
2014-02-06 00:07:05 +00:00
Chandler Carruth
d48cdbf0c3 Put the functionality for printing a value to a raw_ostream as an
operand into the Value interface just like the core print method is.
That gives a more conistent organization to the IR printing interfaces
-- they are all attached to the IR objects themselves. Also, update all
the users.

This removes the 'Writer.h' header which contained only a single function
declaration.

llvm-svn: 198836
2014-01-09 02:29:41 +00:00
Chandler Carruth
9aca918df9 Move the LLVM IR asm writer header files into the IR directory, as they
are part of the core IR library in order to support dumping and other
basic functionality.

Rename the 'Assembly' include directory to 'AsmParser' to match the
library name and the only functionality left their -- printing has been
in the core IR library for quite some time.

Update all of the #includes to match.

All of this started because I wanted to have the layering in good shape
before I started adding support for printing LLVM IR using the new pass
infrastructure, and commandline support for the new pass infrastructure.

llvm-svn: 198688
2014-01-07 12:34:26 +00:00
Jakub Staszak
d4d94065e3 Use switch instead of if. No functionality change.
llvm-svn: 186892
2013-07-22 23:38:16 +00:00
Benjamin Kramer
3d90a8f4f9 Reassociate: Remove unnecessary default operator=.
llvm-svn: 185757
2013-07-06 15:10:13 +00:00
Shuxin Yang
04a4fd43aa Fix a XOR reassociation bug.
When Reassociator optimize "(x | C1)" ^ "(X & C2)", it may swap the two
subexpressions, however, it forgot to swap cached constants (of C1 and C2)
accordingly.

rdar://13739160

llvm-svn: 180676
2013-04-27 18:02:12 +00:00
Shuxin Yang
331f01dcb4 Redo the fix Benjamin Kramer committed in r178793 about iterator invalidation in Reassociate.
I brazenly think this change is slightly simpler than r178793 because: 
  - no "state" in functor
  - "OpndPtrs[i]" looks simpler than "&Opnds[OpndIndices[i]]" 

  While I can reproduce the probelm in Valgrind, it is rather difficult to come up
a standalone testing case. The reason is that when an iterator is invalidated,
the stale invalidated elements are not yet clobbered by nonsense data, so the
optimizer can still proceed successfully. 

  Thank Benjamin for fixing this bug and generously providing the test case.

llvm-svn: 179062
2013-04-08 22:00:43 +00:00
Benjamin Kramer
dd67654af6 Reassociate: Avoid iterator invalidation.
OpndPtrs stored pointers into the Opnd vector that became invalid when the
vector grows. Store indices instead. Sadly I only have a large testcase that
only triggers under valgrind, so I didn't include it.

llvm-svn: 178793
2013-04-04 21:15:42 +00:00
Shuxin Yang
6662fd0f15 Correct assertion condition
llvm-svn: 178484
2013-04-01 18:13:05 +00:00
Shuxin Yang
7b0c94e207 Implement XOR reassociation. It is based on following rules:
rule 1: (x | c1) ^ c2 => (x & ~c1) ^ (c1^c2),
     only useful when c1=c2
  rule 2: (x & c1) ^ (x & c2) = (x & (c1^c2))
  rule 3: (x | c1) ^ (x | c2) = (x & c3) ^ c3 where c3 = c1 ^ c2
  rule 4: (x | c1) ^ (x & c2) => (x & c3) ^ c1, where c3 = ~c1 ^ c2

 It reduces an application's size (in terms of # of instructions) by 8.9%.
 Reviwed by Pete Cooper. Thanks a lot!

 rdar://13212115  

llvm-svn: 178409
2013-03-30 02:15:01 +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
Duncan Sands
79cf530d56 Remove the last bit of constant folding from LinearizeExprTree (most of it was
removed in commit 168035, but I missed this bit).

llvm-svn: 168292
2012-11-18 20:15:36 +00:00
Duncan Sands
20bd7fa0f7 Fix PR14060, an infinite loop in reassociate. The problem was that one of the
operands of the expression being written was wrongly thought to be reusable as
an inner node of the expression resulting in it turning up as both an inner node
*and* a leaf, creating a cycle in the def-use graph.  This would have caused the
verifier to blow up if things had gotten that far, however it managed to provoke
an infinite loop first.

llvm-svn: 168291
2012-11-18 19:27:01 +00:00
Duncan Sands
ac852c742f Fix a crash observed by Shuxin Yang. The issue here is that LinearizeExprTree,
the utility for extracting a chain of operations from the IR, thought that it
might as well combine any constants it came across (rather than just returning
them along with everything else).  On the other hand, the factorization code
would like to see the individual constants (this is quite reasonable: it is
much easier to pull a factor of 3 out of 2*3 than it is to pull it out of 6;
you may think 6/3 isn't so hard, but due to overflow it's not as easy to undo
multiplications of constants as it may at first appear).  This patch therefore
makes LinearizeExprTree stupider: it now leaves optimizing to the optimization
part of reassociate, and sticks to just analysing the IR.

llvm-svn: 168035
2012-11-15 09:58:38 +00:00
Shuxin Yang
c94c3bb5d0 revert r167740
llvm-svn: 167787
2012-11-13 00:08:49 +00:00
Shuxin Yang
1c442f5ec6 This change is to fix rdar://12571717 which is about assertion in Reassociate pass.
The assertion is trigged when the Reassociater tries to transform expression
     ... + 2 * n * 3 + 2 * m + ...
  into:
     ... + 2 * (n*3 + m).

In the process of the transformation, a helper routine folds the constant 2*3 into 6,
confusing optimizer which is trying the to eliminate the common factor 2, and cannot
find 2 any more. 

Review is pending. But I'd like commit first in order to help those who are waiting 
for this fix. 

llvm-svn: 167740
2012-11-12 19:34:11 +00:00
Duncan Sands
5651452076 Stop reassociate from looking through expressions of arbitrary complexity. This
is a temporary measure until my fix for PR13021 is ready.

llvm-svn: 160778
2012-07-26 09:26:40 +00:00
Nadav Rotem
465834c85f Clean whitespaces.
llvm-svn: 160668
2012-07-24 10:51:42 +00:00
Nadav Rotem
1088811c33 Suppress a warning.
llvm-svn: 160629
2012-07-23 13:44:15 +00:00
Duncan Sands
9838286d9e Rework this to clarify where the removal of nodes from the queue is
really happening.  No intended functionality change.

llvm-svn: 159451
2012-06-29 19:03:05 +00:00
Duncan Sands
369c6d270b Fix a reassociate crash on sozefx when compiling with dragonegg+gcc-4.7 due to
the optimizers producing a multiply expression with more multiplications than
the original (!).

llvm-svn: 159426
2012-06-29 13:25:06 +00:00
Chandler Carruth
aafe0918bc Move llvm/Support/IRBuilder.h -> llvm/IRBuilder.h
This was always part of the VMCore library out of necessity -- it deals
entirely in the IR. The .cpp file in fact was already part of the VMCore
library. This is just a mechanical move.

I've tried to go through and re-apply the coding standard's preferred
header sort, but at 40-ish files, I may have gotten some wrong. Please
let me know if so.

I'll be committing the corresponding updates to Clang and Polly, and
Duncan has DragonEgg.

Thanks to Bill and Eric for giving the green light for this bit of cleanup.

llvm-svn: 159421
2012-06-29 12:38:19 +00:00