Commit Graph

73 Commits

Author SHA1 Message Date
Dan Gohman
485c43fc47 Factor out duplicated code for reusing and inserting casts into
a helper function.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106388 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-19 13:25:23 +00:00
Dan Gohman
25fcaff409 LSR needs to remember inserted instructions even in postinc mode, because
there could be multiple subexpressions within a single expansion which
require insert point adjustment. This fixes PR7306.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105510 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-05 00:33:07 +00:00
Dan Gohman
448db1cdef Generalize IVUsers to track arbitrary expressions rather than expressions
explicitly split into stride-and-offset pairs. Also, add the
ability to track multiple post-increment loops on the same expression.

This refines the concept of "normalizing" SCEV expressions used for
to post-increment uses, and introduces a dedicated utility routine for
normalizing and denormalizing expressions.

This fixes the expansion of expressions which are post-increment users
of more than one loop at a time. More broadly, this takes LSR another
step closer to being able to reason about more than one loop at a time.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100699 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-07 22:27:08 +00:00
Dan Gohman
472fdf7090 Clear the SCEVExpander's insertion point after making deletions,
so that the SCEVExpander doesn't retain a dangling pointer as its
insert position. The dangling pointer in this case wasn't ever used
to insert new instructions, but it was causing trouble with
SCEVExpander's code for automatically advancing its insert position
past debug intrinsics.

This fixes use-after-free errors that valgrind noticed in
test/Transforms/IndVarSimplify/2007-06-06-DeleteDanglesPtr.ll and
test/Transforms/IndVarSimplify/exit_value_tests.ll.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99036 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-20 03:53:53 +00:00
Dan Gohman
6c7ed6b549 Fix more places to more thoroughly ignore debug intrinsics. This fixes
use-before-def errors in SCEVExpander-produced code in sqlite3 when debug
info with optimization is enabled, though the testcases for this are
dependent on use-list order.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99001 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-19 21:51:03 +00:00
Dan Gohman
4559855013 When restoring a saved insert location, check to see if the saved
insert location has become an "inserted" instruction since the time
it was saved. If so, advance to the first non-"inserted" instruction.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96203 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-15 00:21:43 +00:00
Dan Gohman
1d826a76f5 In rememberInstruction, if the value being remembered is the
current insertion point, advance the current insertion point.
This avoids a use-before-def situation in a testcase extracted
from clang which is difficult to reduce to a reasonable-sized
regression test.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96151 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-14 03:12:47 +00:00
Dan Gohman
9269926bfb Remove a 'protected' keyword, now that SCEVExpander is no longer
intended to be subclassed.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96149 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-14 02:47:26 +00:00
Dan Gohman
572645cf84 Reapply the new LoopStrengthReduction code, with compile time and
bug fixes, and with improved heuristics for analyzing foreign-loop
addrecs.

This change also flattens IVUsers, eliminating the stride-oriented
groupings, which makes it easier to work with.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95975 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-12 10:34:29 +00:00
Dan Gohman
0f5efe5625 Remove SCEVAllocSizeExpr and SCEVFieldOffsetExpr, and in their place
use plain SCEVUnknowns with ConstantExpr::getSizeOf and
ConstantExpr::getOffsetOf constants. This eliminates a bunch of
special-case code.

Also add code for pattern-matching these expressions, for clients that
want to recognize them.

Move ScalarEvolution's logic for expanding array and vector sizeof
expressions into an element count times the element size, to expose
the multiplication to subsequent folding, into the regular constant
folder.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94737 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-28 02:15:55 +00:00
Dan Gohman
7979b72feb Revert LoopStrengthReduce.cpp to pre-r94061 for now.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94123 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-22 00:46:49 +00:00
Dan Gohman
a10756ee65 Re-implement the main strength-reduction portion of LoopStrengthReduction.
This new version is much more aggressive about doing "full" reduction in
cases where it reduces register pressure, and also more aggressive about
rewriting induction variables to count down (or up) to zero when doing so
reduces register pressure.

It currently uses fairly simplistic algorithms for finding reuse
opportunities, but it introduces a new framework allows it to combine
multiple strategies at once to form hybrid solutions, instead of doing
all full-reduction or all base+index.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94061 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-21 02:09:26 +00:00
Chris Lattner
f55eeb918e remove some more Context arguments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86235 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-06 05:59:53 +00:00
Dan Gohman
4c0d5d5db8 Various comment and whitespace cleanups.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79533 91177308-0d34-0410-b5e6-96231b3b80d8
2009-08-20 16:42:55 +00:00
Dan Gohman
c40f17b087 Generalize ScalarEvolution to be able to analyze GEPs when
TargetData is not present. It still uses TargetData when available.
This generalization also fixed some limitations in the TargetData
case; the attached testcase covers this.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79344 91177308-0d34-0410-b5e6-96231b3b80d8
2009-08-18 16:46:41 +00:00
Owen Anderson
e922c02019 Get rid of the Pass+Context magic.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76702 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-22 00:24:57 +00:00
Dan Gohman
03ee68a145 Forward-declare Loop and LoopInfo instead of #including LoopInfo.h.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75529 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-13 22:19:41 +00:00
Owen Anderson
45524c58fd Finish pushing LLVMContext through the IRBuilder/ConstantFolder interface.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75213 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-10 00:49:53 +00:00
Owen Anderson
d1fbd14294 Push LLVMContext _back_ through IRBuilder.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75040 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-08 20:50:47 +00:00
Dan Gohman
0bba49cebc Change all SCEV* to SCEV *.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74918 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-07 17:06:11 +00:00
Owen Anderson
76f600b205 Finish LLVMContext-ing lib/Analysis. This required pushing LLVMContext's through the ValueTracking API.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74873 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-06 22:37:39 +00:00
Owen Anderson
508955156a Thread LLVMContext through the constant folding APIs, which touches a lot of files.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74844 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-06 18:42:36 +00:00
Dan Gohman
267a385342 Change SCEVExpander to use an IRBuilder to emit instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74391 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-27 21:18:18 +00:00
Dan Gohman
667d787c0a Incorporate the insertion point into the key of SCEVExpander's CSE map.
This helps it avoid reusing an instruction that doesn't dominate all
of the users, in cases where the original instruction was inserted
before all of the users were known.  This may result in redundant
expansions of sub-expressions that depend on loop-unpredictable values
in some cases, however this isn't very common, and it primarily impacts
IndVarSimplify, so GVN can be expected to clean these up.

This eliminates the need for IndVarSimplify's FixUsesBeforeDefs,
which fixes several bugs.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74352 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-26 22:53:46 +00:00
Owen Anderson
372b46cad9 SCEVHandle is no more!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73906 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-22 21:39:50 +00:00
Dan Gohman
1d09de3eca Move SCEVExpander::getOrInsertCanonicalInductionVariable out of line.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72949 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-05 16:35:53 +00:00
Dan Gohman
453aa4fbf1 Generalize SCEVExpander::visitAddRecExpr's GEP persuit, and avoid
sending SCEVUnknowns to expandAddToGEP. This avoids the need for
expandAddToGEP to bend the rules and peek into SCEVUnknown
expressions.

Factor out the code for testing whether a SCEV can be factored by
a constant for use in a GEP index. This allows it to handle
SCEVAddRecExprs, by recursing.

As a result, SCEVExpander can now put more things in GEP indices,
so it emits fewer explicit mul instructions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72366 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-24 18:06:31 +00:00
Torok Edwin
b679de2a21 The rewriter may hold references to instructions that are deleted because they are trivially dead.
Fix by clearing the rewriter cache before deleting the trivially dead
instructions.
Also make InsertedExpressions use an AssertingVH to catch these
bugs easier.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72364 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-24 14:23:16 +00:00
Dan Gohman
5be18e8476 Teach SCEVExpander to expand arithmetic involving pointers into GEP
instructions. It attempts to create high-level multi-operand GEPs,
though in cases where this isn't possible it falls back to casting
the pointer to i8* and emitting a GEP with that. Using GEP instructions
instead of ptrtoint+arithmetic+inttoptr helps pointer analyses that
don't use ScalarEvolution, such as BasicAliasAnalysis.

Also, make the AddrModeMatcher more aggressive in handling GEPs.
Previously it assumed that operand 0 of a GEP would require a register
in almost all cases. It now does extra checking and can do more
matching if operand 0 of the GEP is foldable. This fixes a problem
that was exposed by SCEVExpander using GEPs.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72093 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-19 02:15:55 +00:00
Dan Gohman
cf5ab82022 Actually insert inserted instructions into the InsertedValues map.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70557 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-01 17:13:31 +00:00
Dan Gohman
b52e1c587f Add an accessor method to allow clients to test if a given expression
is associated with a SCEV expansion.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70556 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-01 17:08:34 +00:00
Dan Gohman
99a1302ae4 Make SCEVExpander::addInsertedValue able to accept Values, not just
Instructions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70552 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-01 16:58:31 +00:00
Dan Gohman
752ec7da50 Change SCEVExpander's expandCodeFor to provide more flexibility
with the persistent insertion point, and change IndVars to make
use of it. This fixes a bug where IndVars was holding on to a
stale insertion point and forcing the SCEVExpander to continue to
use it.

This fixes PR4038.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69892 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-23 15:16:49 +00:00
Dan Gohman
6cdc727f2d Use BasicBlock::iterator instead of Instruction* for insert points,
to better handle inserting instructions at the end of a block.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69807 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-22 16:05:50 +00:00
Dan Gohman
b928c57397 Make SCEVExpanders private methods private, instead of protected.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69806 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-22 16:00:36 +00:00
Dan Gohman
af79fb5f47 Introduce encapsulation for ScalarEvolution's TargetData object, and refactor
the code to minimize dependencies on TargetData.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69644 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-21 01:07:12 +00:00
Dan Gohman
890f92b744 Use more const qualifiers with SCEV interfaces.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69450 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-18 17:56:28 +00:00
Dan Gohman
f04fa483b8 Teach SCEVExpander::InsertCastOfTo to avoid creating inttoptr-of-ptrtoint
and ptrtoint-of-inttoptr expressions. This fixes a regression in 300.twolf.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69293 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-16 15:52:57 +00:00
Dan Gohman
2d1be87ee4 Expand GEPs in ScalarEvolution expressions. SCEV expressions can now
have pointer types, though in contrast to C pointer types, SCEV
addition is never implicitly scaled. This not only eliminates the
need for special code like IndVars' EliminatePointerRecurrence
and LSR's own GEP expansion code, it also does a better job because
it lets the normal optimizations handle pointer expressions just
like integer expressions.

Also, since LLVM IR GEPs can't directly index into multi-dimensional
VLAs, moving the GEP analysis out of client code and into the SCEV
framework makes it easier for clients to handle multi-dimensional
VLAs the same way as other arrays.

Some existing regression tests show improved optimization.
test/CodeGen/ARM/2007-03-13-InstrSched.ll in particular improved to
the point where if-conversion started kicking in; I turned it off
for this test to preserve the intent of the test.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69258 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-16 03:18:22 +00:00
Nick Lewycky
789558db70 Wind SCEV back in time, to Nov 18th. This 'fixes' PR3275, PR3294, PR3295,
PR3296 and PR3302.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62160 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-13 09:18:58 +00:00
Dan Gohman
d68a07650c Tidy up #includes, deleting a bunch of unnecessary #includes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61715 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-05 17:59:02 +00:00
Nick Lewycky
48dd644109 Add a new SCEV representing signed division.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60407 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-02 08:05:48 +00:00
Nick Lewycky
6177fd4fce Expand SCEVUDiv of power of 2 to a lshr instruction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53217 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-08 05:05:37 +00:00
Dan Gohman
11f6d3b478 Move a few more SCEVExpander methods out-of-line.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52612 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-22 19:09:18 +00:00
Dan Gohman
e24fa64d52 Move SCEVExpander::visitAddExpr out-of-line.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52464 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-18 16:37:11 +00:00
Wojciech Matyjewicz
8a08769bad Fix PR2434. When scanning for exising binary operator to reuse don't
take into account the instrucion pointed by InsertPt. Thanks to it, 
returning the new value of InsertPt to the InsertBinop() caller can be 
avoided. The bug was, actually, in visitAddRecExpr() method which wasn't 
correctly handling changes of InsertPt. There shouldn't be any 
performance regression, as -gvn pass (run after -indvars) removes any 
redundant binops.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52291 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-15 19:07:39 +00:00
Dan Gohman
1baa88e3de Prune and tidy #includes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51697 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-29 19:52:31 +00:00
Gabor Greif
7cbd8a3e92 API change for {BinaryOperator|CmpInst|CastInst}::create*() --> Create. Legacy interfaces will be in place for some time. (Merge from use-diet branch.)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51200 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-16 19:29:10 +00:00
Nick Lewycky
3e63076980 Add 'umax' similar to 'smax' SCEV. Closes PR2003.
Parse reversed smax and umax as smin and umin and express them with negative
or binary-not SCEVs (which are really just subtract under the hood).

Parse 'xor %x, -1' as (-1 - %x).

Remove dead code (ConstantInt::get always returns a ConstantInt).

Don't use getIntegerSCEV(-1, Ty). The first value is an int, then it gets
passed into a uint64_t. Instead, create the -1 directly from
ConstantInt::getAllOnesValue().


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47360 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-20 06:48:22 +00:00
Wojciech Matyjewicz
e3320a1bcc Fix PR1798 - an error in the evaluation of SCEVAddRecExpr at an
arbitrary iteration.

The patch:
1) changes SCEVSDivExpr into SCEVUDivExpr,
2) replaces PartialFact() function with BinomialCoefficient(); the 
computations (essentially, the division) in BinomialCoefficient() are 
performed with the apprioprate bitwidth necessary to avoid overflow; 
unsigned division is used instead of the signed one.

Computations in BinomialCoefficient() require support from the code 
generator for APInts. Currently, we use a hack rounding up the 
neccessary bitwidth to the nearest power of 2. The hack is easy to turn 
off in future.

One remaining issue: we assume the divisor of the binomial coefficient 
formula can be computed accurately using 16 bits. It means we can handle 
AddRecs of length up to 9. In future, we should use APInts to evaluate 
the divisor.

Thanks to Nicholas for cooperation!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46955 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-11 11:03:14 +00:00