Commit Graph

576 Commits

Author SHA1 Message Date
Nadav Rotem 51f71054b6 Fix MSVC warnings by adding a cast.
llvm-svn: 144721
2011-11-15 22:54:21 +00:00
Eli Friedman b46345d7c1 Avoid undefined behavior in negation in LSR. Patch by Ahmed Charles.
Someone more familiar with LSR should double-check that the extra cast is actually doing the right thing in the overflow cases; I'm not completely confident that's that case. 

llvm-svn: 141916
2011-10-13 23:48:33 +00:00
Andrew Trick ecbe22bb8d Add experimental -enable-lsr-phielim option.
I'm not sure we will need it in the long run, but the option is
currently useful for checking if the output of LSR is "clean".

llvm-svn: 141634
2011-10-11 02:30:45 +00:00
Andrew Trick 7fb669ab48 LSR should only reuse phis that match its formula.
Fixes rdar://problem/5064068

llvm-svn: 141442
2011-10-07 23:46:21 +00:00
Andrew Trick 8de329a9fc LSR should avoid redundant edge splitting.
This handles the case in which LSR rewrites an IV user that is a phi and
splits critical edges originating from a switch.
Fixes <rdar://problem/6453893> LSR is not splitting edges "nicely"

llvm-svn: 141059
2011-10-04 03:50:44 +00:00
Andrew Trick 168dfffdb8 typo + pasto
llvm-svn: 140769
2011-09-29 01:53:08 +00:00
Andrew Trick bc6de90a5f LSR: rewrite inner loops only.
Rewriting the entire loop nest now requires -enable-lsr-nested.
See PR11035 for some performance data.
A few unit tests specifically test nested LSR, and are now under a flag.

llvm-svn: 140762
2011-09-29 01:33:38 +00:00
Andrew Trick 581243919d Disable LSR retry by default.
Disabling aggressive LSR saves compilation time, and with the new
indvars behavior usually improves performance.

llvm-svn: 140590
2011-09-27 00:44:14 +00:00
Andrew Trick 8868faec63 LSR, one of the new Cost::isLoser() checks did not get merged in the previous checkin.
llvm-svn: 140583
2011-09-26 23:35:25 +00:00
Andrew Trick 784729d408 LSR cost metric minor fix and verification.
The minor bug heuristic was noticed by inspection. I added the
isLoser/isValid helpers because they will become more
important with subsequent checkins.

llvm-svn: 140580
2011-09-26 23:11:04 +00:00
Andrew Trick 8b2fe2f744 LSR minor bug fix in RateRegister.
No test case. Noticed by inspection and I doubt it ever affects the
outcome of the overall heuristic, let alone final codegen.

llvm-svn: 140431
2011-09-23 23:05:19 +00:00
Bill Wendling 3fb137f7ef LSR wants to split the landing pad's critical edge. Let it do it, but use the
proper function to do it.

llvm-svn: 138550
2011-08-25 05:55:40 +00:00
Bill Wendling 07efd6f1e0 When inserting new instructions, use getFirstInsertionPt instead of
getFirstNonPHI so that it will skip over the landingpad instructions as well.

llvm-svn: 138537
2011-08-25 01:08:34 +00:00
Bill Wendling 86c5cbe613 Skip the landingpad instruction when determining the insertion point.
llvm-svn: 138481
2011-08-24 21:06:46 +00:00
Andrew Trick bd243d0dfe LSR, correct fix for rdar://9786536. Silly casting bug.
llvm-svn: 135654
2011-07-21 01:45:54 +00:00
Andrew Trick 858e9f083d LSR must sometimes sign-extend before generating double constants.
rdar://9786536

llvm-svn: 135650
2011-07-21 01:05:01 +00:00
Andrew Trick 8acb434402 LSR crashes on an empty IVUsers list.
rdar://9786536

llvm-svn: 135644
2011-07-21 00:40:04 +00:00
Chris Lattner 229907cd11 land David Blaikie's patch to de-constify Type, with a few tweaks.
llvm-svn: 135375
2011-07-18 04:54:35 +00:00
Chris Lattner b1a1512119 start using the new helper methods a bit.
llvm-svn: 135251
2011-07-15 06:08:15 +00:00
Andrew Trick 411daa5e81 SCEVExpander: give new insts a name that identifies the reponsible pass.
llvm-svn: 133992
2011-06-28 05:07:32 +00:00
Andrew Trick fc4ccb20c6 IVUsers no longer needs to record the phis.
llvm-svn: 133518
2011-06-21 15:43:52 +00:00
Dan Gohman 6c4a319088 When checking for signed multiplication overflow, watch out for INT_MIN and -1.
This fixes PR9845.

llvm-svn: 131919
2011-05-23 21:07:39 +00:00
Andrew Trick f44aadf0fd indvars: Prototyping Sign/ZeroExtend elimination without canonical IVs.
No functionality enabled by default. Use -disable-iv-rewrite.
Extended IVUsers to keep track of the phi that represents the users' IV.
Added the WidenIV transform to replace a narrow IV with a wide IV
by doing a one-for-one replacement of IV users instead of expanding the
SCEV expressions. [sz]exts are removed and truncs are inserted.

llvm-svn: 131744
2011-05-20 18:25:42 +00:00
Dan Gohman 3268e4d692 When forming an ICmpZero LSRUse, normalize the non-IV operand
of the comparison, so that the resulting expression is fully
normalized. This fixes PR9939.

llvm-svn: 131576
2011-05-18 21:02:18 +00:00
Dan Gohman 6136e94897 Add an unfolded offset field to LSR's Formula record. This is used to
model constants which can be added to base registers via add-immediate
instructions which don't require an additional register to materialize
the immediate.

llvm-svn: 130743
2011-05-03 00:46:49 +00:00
Chris Lattner 0ab5e2cded Fix a ton of comment typos found by codespell. Patch by
Luis Felipe Strano Moraes!

llvm-svn: 129558
2011-04-15 05:18:47 +00:00
Bill Wendling b902f1dd88 Reapply r129401 with patch for clang.
llvm-svn: 129419
2011-04-13 00:36:11 +00:00
Bill Wendling dbfde42468 Revert r129401 for now. Clang is using the old way of doing things.
llvm-svn: 129403
2011-04-12 22:59:27 +00:00
Bill Wendling 47c24875a1 Remove the unaligned load intrinsics in favor of using native unaligned loads.
Now that we have a first-class way to represent unaligned loads, the unaligned
load intrinsics are superfluous.

First part of <rdar://problem/8460511>.

llvm-svn: 129401
2011-04-12 22:46:31 +00:00
Jay Foad 52131344a2 Remove PHINode::reserveOperandSpace(). Instead, add a parameter to
PHINode::Create() giving the (known or expected) number of operands.

llvm-svn: 128537
2011-03-30 11:28:46 +00:00
Jay Foad e0938d8a87 (Almost) always call reserveOperandSpace() on newly created PHINodes.
llvm-svn: 128535
2011-03-30 11:19:20 +00:00
Andrew Trick 8b55b736b1 Added SCEV::NoWrapFlags to manage unsigned, signed, and self wrap
properties.
Added the self-wrap flag for SCEV::AddRecExpr.
A slew of temporary FIXMEs indicate the intention of the no-self-wrap flag
without changing behavior in this revision.

llvm-svn: 127590
2011-03-14 16:50:06 +00:00
Cameron Zwarich 97dae4d361 If we can't avoid running loop-simplify twice for now, at least avoid running
iv-users twice.

llvm-svn: 125318
2011-02-10 23:53:14 +00:00
Eric Christopher da6bd45088 Revert this in an attempt to bring the builders back.
llvm-svn: 125257
2011-02-10 01:48:24 +00:00
Cameron Zwarich 58c8670ab2 Turn this pass ordering:
Natural Loop Information
 Loop Pass Manager
   Canonicalize natural loops
 Scalar Evolution Analysis
 Loop Pass Manager
   Induction Variable Users
   Canonicalize natural loops
   Induction Variable Users
   Loop Strength Reduction

into this:

Scalar Evolution Analysis
Loop Pass Manager
  Canonicalize natural loops
  Induction Variable Users
  Loop Strength Reduction

This fixes <rdar://problem/8869639>. I also filed PR9184 on doing this sort of
thing automatically, but it seems easier to just change the ordering of the
passes if this is the only case.

llvm-svn: 125254
2011-02-10 01:07:54 +00:00
Dan Gohman de7f699754 Don't split any loop backedges, including backedges of loops other than
the active loop. This is generally desirable, and it avoids trouble
in situations such as the testcase in PR9123, though the failure
mode depends on use-list order, so it is infeasible to test.

llvm-svn: 125065
2011-02-08 00:55:13 +00:00
Cameron Zwarich b703654edc Remove code for updating dominance frontiers and some outdated references to
dominance and post-dominance frontiers.

llvm-svn: 123725
2011-01-18 04:11:31 +00:00
Chris Lattner bf0aa927cc split dom frontier handling stuff out to its own DominanceFrontier header,
so that Dominators.h is *just* domtree.  Also prune #includes a bit.

llvm-svn: 122714
2011-01-02 22:09:33 +00:00
Dan Gohman 20d9ce21ef Move SCEV::dominates and properlyDominates to ScalarEvolution.
llvm-svn: 119570
2010-11-17 21:41:58 +00:00
Dan Gohman afd6db9932 Move SCEV::isLoopInvariant and hasComputableLoopEvolution to be member
functions of ScalarEvolution, in preparation for memoization and
other optimizations.

llvm-svn: 119562
2010-11-17 21:23:15 +00:00
Owen Anderson a4fefc1949 Passes do not need to recursively initialize passes that they preserve, if
they do not also require them.  This allows us to reduce inter-pass linkage
dependencies.

llvm-svn: 116854
2010-10-19 20:08:44 +00:00
Owen Anderson 6c18d1aac0 Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which
must be called in the pass's constructor.  This function uses static dependency declarations to recursively initialize
the pass's dependencies.

Clients that only create passes through the createFooPass() APIs will require no changes.  Clients that want to use the
CommandLine options for passes will need to manually call the appropriate initialization functions in PassInitialization.h
before parsing commandline arguments.

I have tested this with all standard configurations of clang and llvm-gcc on Darwin.  It is possible that there are problems
with the static dependencies that will only be visible with non-standard options.  If you encounter any crash in pass
registration/creation, please send the testcase to me directly.

llvm-svn: 116820
2010-10-19 17:21:58 +00:00
Owen Anderson 8ac477ffb5 Begin adding static dependence information to passes, which will allow us to
perform initialization without static constructors AND without explicit initialization
by the client.  For the moment, passes are required to initialize both their
(potential) dependencies and any passes they preserve.  I hope to be able to relax
the latter requirement in the future.

llvm-svn: 116334
2010-10-12 19:48:12 +00:00
Dan Gohman 2fd85d7cd2 Filter out illegal formulae after updating offsets, not before, so that
formulae which become illegal as a result of the offset updating don't
escape.

This is for rdar://8529692. No testcase yet, because the given cases
hit use-list ordering differences.

llvm-svn: 116093
2010-10-08 19:33:26 +00:00
Dan Gohman 5947e1626a Delete the FormulaSorter class and inline its one method into its
one user. This code will be restructured soon and FormulaSorter
is getting in the way.

llvm-svn: 116012
2010-10-07 23:52:18 +00:00
Dan Gohman 1b61fd9bff Fix a spello.
llvm-svn: 116011
2010-10-07 23:43:09 +00:00
Dan Gohman 34f37e0d04 Charge a formula for explicit multiplies on scaled registers too,
not just base registers.

llvm-svn: 116010
2010-10-07 23:41:58 +00:00
Dan Gohman 49d638b45a Use size_t for consistency.
llvm-svn: 116009
2010-10-07 23:37:58 +00:00
Dan Gohman 8e72611058 When merging one use into another, transfer the offsets from
the old use to the new one.

llvm-svn: 116008
2010-10-07 23:36:45 +00:00
Dan Gohman a7b68d6d95 Fix LSR to keep the RegUseTracker up to date when combining users.
This doesn't usually matter, because the other heuristics usually
succeed regardless, but it's good to keep the register use
bookkeeping consistent.

llvm-svn: 116005
2010-10-07 23:33:43 +00:00
Owen Anderson df7a4f2515 Now with fewer extraneous semicolons!
llvm-svn: 115996
2010-10-07 22:25:06 +00:00
Dan Gohman 16ef49686c Delete an unused function.
llvm-svn: 114841
2010-09-27 16:58:21 +00:00
Gabor Greif a06741b356 do not rely on the implicit-dereference semantics of dyn_cast_or_null
llvm-svn: 114278
2010-09-18 11:55:34 +00:00
Dan Gohman 110ed64fbb Revert 112442 and 112440 until the compile time problems introduced
by 112440 are resolved.

llvm-svn: 112692
2010-09-01 01:45:53 +00:00
Dan Gohman 002ff89cbd Optionally rerun dedicated-register filtering after applying
other filtering techniques, as those may allow it to filter
out more obviously unprofitable candidates.

llvm-svn: 112441
2010-08-29 16:39:22 +00:00
Dan Gohman f031792cc6 Fix several areas in LSR to do a better job keeping the main
LSRInstance data structures up to date. This fixes some
pessimizations caused by stale data which will be exposed
in an upcoming change.

llvm-svn: 112440
2010-08-29 16:32:54 +00:00
Dan Gohman e9e0873b08 Refactor the three main groups of code out of
NarrowSearchSpaceUsingHeuristics into separate functions.

llvm-svn: 112439
2010-08-29 16:09:42 +00:00
Dan Gohman 37a0f68036 Delete a bogus check.
llvm-svn: 112438
2010-08-29 15:30:29 +00:00
Dan Gohman b6a520d63c Add some comments.
llvm-svn: 112437
2010-08-29 15:27:08 +00:00
Dan Gohman bf673e0652 Move this debug output into GenerateAllReuseFormula, to declutter
the high-level logic.

llvm-svn: 112436
2010-08-29 15:21:38 +00:00
Dan Gohman d366b6d5c8 Delete an unused declaration.
llvm-svn: 112435
2010-08-29 15:19:11 +00:00
Dan Gohman 4f13bbfefc Do one lookup instead of two.
llvm-svn: 112434
2010-08-29 15:18:49 +00:00
Dan Gohman 129a816ee6 Process the step before the start, because it's usually the simpler
of the two.

llvm-svn: 111495
2010-08-19 01:02:31 +00:00
Dan Gohman 89fdbaf99a Instead of having CollectSubexpr's categorize operands as interesting or
uninteresting, just put all the operands on one list and make
GenerateReassociations make the decision about what's interesting.
This is simpler, and it avoids an extra ScalarEvolution::getAddExpr call.

llvm-svn: 111133
2010-08-16 15:50:00 +00:00
Dan Gohman 9b7632df26 Put add operands in ScalarEvolution-canonical order, when convenient.
This isn't necessary, because ScalarEvolution sorts them anyway,
but it's tidier this way.

llvm-svn: 111132
2010-08-16 15:39:27 +00:00
Dan Gohman 081ffcd00b Fix LSR's ExtractImmediate and ExtractSymbol to avoid calling
ScalarEvolution::getAddExpr, which can be pretty expensive, when nothing
has changed, which is pretty common.

llvm-svn: 111042
2010-08-13 21:17:19 +00:00
Owen Anderson a7aed18624 Reapply r110396, with fixes to appease the Linux buildbot gods.
llvm-svn: 110460
2010-08-06 18:33:48 +00:00
Owen Anderson bda59bd247 Revert r110396 to fix buildbots.
llvm-svn: 110410
2010-08-06 00:23:35 +00:00
Owen Anderson 755aceb5d0 Don't use PassInfo* as a type identifier for passes. Instead, use the address of the static
ID member as the sole unique type identifier.  Clean up APIs related to this change.

llvm-svn: 110396
2010-08-05 23:42:04 +00:00
Dan Gohman ba81fc16a5 Fix whitespace.
llvm-svn: 110223
2010-08-04 17:43:57 +00:00
Oscar Fuentes 40b31ad3ee Prefix `next' iterator operation with `llvm::'.
Fixes potential ambiguity problems on VS 2010.

Patch by nobled!

llvm-svn: 110029
2010-08-02 06:00:15 +00:00
Owen Anderson a57b97e7e7 Fix batch of converting RegisterPass<> to INTIALIZE_PASS().
llvm-svn: 109045
2010-07-21 22:09:45 +00:00
Dan Gohman 1415208292 Don't merge uses when they are targetting fixup sites with
different widths. In a use with a narrower fixup, formulae
may be wider than the fixup, in which case the high bits
aren't necessarily meaningful, so it isn't safe to reuse
them for uses with wider fixups.

This fixes PR7618, though the testcase is too large for a
reasonable regression test, since it heavily dependes on
hitting LSR's heuristics in a certain way.

llvm-svn: 108455
2010-07-15 20:24:58 +00:00
Dan Gohman a1501b9c50 Use dbgs() instead of errs() in a DEBUG.
llvm-svn: 108453
2010-07-15 20:12:42 +00:00
Dan Gohman 4afd412d6b Watch out for a constant offset cancelling out a base register, forming
a zero. This situation arrises in Fortran code with induction variables
that start at 1 instead of 0. This fixes PR7651.

llvm-svn: 108424
2010-07-15 15:14:45 +00:00
Gabor Greif 8ae3095286 use getArgOperand instead of getOperand
llvm-svn: 107270
2010-06-30 09:15:28 +00:00
Dan Gohman fb9712bdae In GenerateReassociations, don't bother thinking about individual
SCEVUnknown values which are loop-variant, as LSR can't do anything
interesting with these values in any case. This fixes very slow compile
times on loops which have large numbers of such values.

llvm-svn: 106897
2010-06-25 22:32:18 +00:00
Dan Gohman 963b1c142e A few minor micro-optimizations.
llvm-svn: 106764
2010-06-24 16:57:52 +00:00
Dan Gohman 47ddf76d89 Teach getExactSDiv to evaluate x/1 to x up front, as it's a common
enough special case, and it theoretically allows more folding because
it works even when x is unanalyzable.

llvm-svn: 106763
2010-06-24 16:51:25 +00:00
Dan Gohman ab5422200b Fix copy+pasto issues in isMulSExtable.
llvm-svn: 106759
2010-06-24 16:45:11 +00:00
Dan Gohman 1081f1a0f5 Fix OptimizeMax to handle an odd case where one of the max operands
is another max which folds. This fixes PR7454.

llvm-svn: 106594
2010-06-22 23:07:13 +00:00
Dan Gohman dd41bba517 Use A.append(...) instead of A.insert(A.end(), ...) when A is a
SmallVector, and other SmallVector simplifications.

llvm-svn: 106452
2010-06-21 19:47:52 +00:00
Dan Gohman 32655906e4 Add a TODO comment.
llvm-svn: 106397
2010-06-19 21:30:18 +00:00
Dan Gohman 51d00092b6 Include the use kind along with the expression in the key of the
use sharing map. The reconcileNewOffset logic already forces a
separate use if the kinds differ, so incorporating the kind in the
key means we can track more sharing opportunities.

More sharing means fewer total uses to track, which means smaller
problem sizes, which means the conservative throttles don't kick
in as often.

llvm-svn: 106396
2010-06-19 21:29:59 +00:00
Dan Gohman 297fb8b9fc Don't include things in anonymous namespaces that don't need it.
llvm-svn: 106395
2010-06-19 21:21:39 +00:00
Dan Gohman 67b4403101 Don't track users of undef values; they aren't interesting for
register pressure.

llvm-svn: 105501
2010-06-04 23:16:05 +00:00
Dan Gohman 9b48b856ea DominatorTree.getNode can return null for unreachable blocks.
llvm-svn: 104290
2010-05-20 22:46:54 +00:00
Dan Gohman 86110fa2bb Minor code cleanups.
llvm-svn: 104287
2010-05-20 22:25:20 +00:00
Dan Gohman 6295f2ebb8 Make Solve check its own post-condition, to reduce clutter in the
top-level LSRInstance logic.

llvm-svn: 104278
2010-05-20 20:59:23 +00:00
Dan Gohman a4ca28a3ae Add comments.
llvm-svn: 104276
2010-05-20 20:52:00 +00:00
Dan Gohman 927bcaadda More code cleanups. Use iterators instead of indices when indices
aren't needed.

llvm-svn: 104273
2010-05-20 20:33:18 +00:00
Dan Gohman 4c4043cf34 Fix OptimizeShadowIV to set Changed. Change OptimizeLoopTermCond to set
Changed directly instead of using a return value.

Rename FilterOutUndesirableDedicatedRegisters's Changed variable to
distinguish it from LSRInstance's Changed member.

llvm-svn: 104269
2010-05-20 20:05:31 +00:00
Dan Gohman 8ec018cedf Add some comments.
llvm-svn: 104268
2010-05-20 20:00:41 +00:00
Dan Gohman 8ce95cc3c5 Simplify this code. Don't do a DomTreeNode lookup for each visited block.
llvm-svn: 104267
2010-05-20 20:00:25 +00:00
Dan Gohman ab5fb7f559 Minor code cleanups.
llvm-svn: 104263
2010-05-20 19:44:23 +00:00
Dan Gohman ee2fea3cd7 When canonicalizing icmp operand order to put the loop invariant
operand on the left, the interesting operand is on the right. This
fixes a bug where LSR was failing to recognize ICmpZero uses,
which led it to be unable to reverse the induction variable in the
attached testcase.

Delete test/CodeGen/X86/stack-color-with-reg-2.ll, because its test
is extremely fragile and hard to meaningfully update.

llvm-svn: 104262
2010-05-20 19:26:52 +00:00
Dan Gohman fdf9874ba7 Set Changed to true when canonicalizing ICmp operand order; even though
it isn't a very interesting change, it's a change nonetheless.

llvm-svn: 104260
2010-05-20 19:16:03 +00:00
Dan Gohman 981563d0ba Rename a variable to avoid shadowing.
llvm-svn: 104234
2010-05-20 16:41:11 +00:00
Dan Gohman 6b733fc189 Minor code simplification.
llvm-svn: 104232
2010-05-20 16:23:28 +00:00
Dan Gohman 80a9608442 Move the code for deleting BaseRegs and LSRUses into helper functions,
and fix a bug that valgrind noticed where the code would std::swap an
element with itself.

llvm-svn: 104225
2010-05-20 15:17:54 +00:00