Commit Graph

421 Commits

Author SHA1 Message Date
Owen Anderson 4056ca9568 Move types back to the 2.5 API.
llvm-svn: 77516
2009-07-29 22:17:13 +00:00
Owen Anderson 487375e9a2 Move ConstantExpr to 2.5 API.
llvm-svn: 77494
2009-07-29 18:55:55 +00:00
Dan Gohman 169ef138e8 Fix wording in comments.
llvm-svn: 77193
2009-07-27 16:09:48 +00:00
Dan Gohman ef2ae2c8ee SCEV objects are no longer reference-counted.
llvm-svn: 77080
2009-07-25 16:18:07 +00:00
Dan Gohman 534d66a426 When attempting to sign-extend an addrec by interpreting
the step value as unsigned, the start value and the addrec
itself still need to be treated as signed.

llvm-svn: 77078
2009-07-25 16:03:30 +00:00
Dan Gohman 62ef6a7f1c Teach ScalarEvolution to make use of no-overflow flags when
analyzing add recurrences.

llvm-svn: 77034
2009-07-25 01:22:26 +00:00
Dan Gohman 0b89dff37d Instead of eagerly creating new SCEVs to replace all SCEVs that are
affected after a PHI node has been analyzed, just remove affected
SCEVs from the Scalars map, so that they'll be (lazily) recreated as
needed. This avoids creating SCEV objects that aren't actually needed.

Also, rewrite the associated def-use walking code to be non-recursive
and to continue traversing past Instructions that don't have an
entry in the Scalars map.

llvm-svn: 77032
2009-07-25 01:13:03 +00:00
Owen Anderson edb4a70325 Revert the ConstantInt constructors back to their 2.5 forms where possible, thanks to contexts-on-types. More to come.
llvm-svn: 77011
2009-07-24 23:12:02 +00:00
Dan Gohman 5ece69a47c Fix whitespace.
llvm-svn: 76929
2009-07-24 01:03:59 +00:00
Owen Anderson 47db941fd3 Get rid of the Pass+Context magic.
llvm-svn: 76702
2009-07-22 00:24:57 +00:00
Dan Gohman 430f0cc544 Replace the original ad-hoc code for determining whether (v pred w) implies
(x pred y) with more thorough code that does more complete canonicalization
before resorting to range checks. This helps it find more cases where
the canonicalized expressions match.

llvm-svn: 76671
2009-07-21 23:03:19 +00:00
Dan Gohman 75dced058a Make the range calculations for addrecs to be more conservative,
as they aren't currently prepared to handle complicated overflow
cases.

llvm-svn: 76524
2009-07-21 00:42:47 +00:00
Dan Gohman 32291b1afc Whitespace cleanups.
llvm-svn: 76523
2009-07-21 00:38:55 +00:00
Dan Gohman d571c37b54 Minor code simplification.
llvm-svn: 76521
2009-07-21 00:37:45 +00:00
Dan Gohman 3439262586 Add a comment to clarify why there isn't any code in this spot.
llvm-svn: 76505
2009-07-20 23:54:43 +00:00
Dan Gohman 00c1aaec5a Remove the code that tried to evaluate whether (A pred B) is known
by determining if (B pred (B-A)) is known, as it doesn't handle
overflow correctly.

llvm-svn: 76504
2009-07-20 23:53:35 +00:00
Dan Gohman d231d78f3f Minor code simplification.
llvm-svn: 76496
2009-07-20 22:41:51 +00:00
Dan Gohman 1a7ab9473f The upper argument of ConstantRange is exclusive, not inclusive.
llvm-svn: 76492
2009-07-20 22:34:18 +00:00
Dan Gohman 33a3fd0b9c Revert the addition of hasNoPointerOverflow to GEPOperator.
Getelementptrs that are defined to wrap are virtually useless to
optimization, and getelementptrs that are undefined on any kind
of overflow are too restrictive -- it's difficult to ensure that
all intermediate addresses are within bounds. I'm going to take
a different approach.

Remove a few optimizations that depended on this flag.

llvm-svn: 76437
2009-07-20 17:43:30 +00:00
Dan Gohman 80ca01c466 Add a new Operator class, for handling Instructions and ConstantExprs
in a convenient manner, factoring out some common code from
InstructionCombining and ValueTracking. Move the contents of
BinaryOperators.h into Operator.h and use Operator to generalize them
to support ConstantExprs as well as Instructions.

llvm-svn: 76232
2009-07-17 20:47:02 +00:00
Owen Anderson 20b34ac794 Move the ConstantInt uniquing table into LLVMContextImpl. This exposed a number of issues in
our current context-passing stuff, which is also fixed here

llvm-svn: 76089
2009-07-16 18:04:31 +00:00
Dan Gohman 8c129d7687 Fill in some holes in ScalarEvolution's loop iteration condition
analysis. This allows indvars to emit a simpler loop trip count
expression.

llvm-svn: 76085
2009-07-16 17:34:36 +00:00
Owen Anderson b6b2530000 Move EVER MORE stuff over to LLVMContext.
llvm-svn: 75703
2009-07-14 23:09:55 +00:00
Torok Edwin fbcc663cbf llvm_unreachable->llvm_unreachable(0), LLVM_UNREACHABLE->llvm_unreachable.
This adds location info for all llvm_unreachable calls (which is a macro now) in
!NDEBUG builds.
In NDEBUG builds location info and the message is off (it only prints
"UREACHABLE executed").

llvm-svn: 75640
2009-07-14 16:55:14 +00:00
Dan Gohman f34f8634e7 Make SCEVCallbackVH::allUsesReplacedWith more thorough in removing
users from the Scalars map.

llvm-svn: 75634
2009-07-14 14:34:04 +00:00
Dan Gohman 92b4c7f355 Add a comment about why ScalarEvolution doesn't recognize non-loop PHIs
even when they're obvious.

llvm-svn: 75632
2009-07-14 14:06:25 +00:00
Owen Anderson 3e42e9f2fc Move more functionality over to LLVMContext.
llvm-svn: 75559
2009-07-13 23:50:59 +00:00
Dan Gohman fda3c4ac89 Print a newline after printing a Value, now that Value's operator<<
doesn't print a newline.

llvm-svn: 75543
2009-07-13 23:03:05 +00:00
Dan Gohman dd707af345 Fix a few assertion strings.
llvm-svn: 75530
2009-07-13 22:20:53 +00:00
Dan Gohman fc7699405c Whitespace cleanups.
llvm-svn: 75525
2009-07-13 22:05:32 +00:00
Dan Gohman e6b4babcbb Fix an 80-column violation.
llvm-svn: 75524
2009-07-13 22:04:06 +00:00
Dan Gohman e65c917ecf Reapply 75252, with a fix to avoid the infinite recursion case. The
check for avoiding re-analyzing a widening cast needed to happen
earlier, as getSCEV itself may result in a isLoopGuardedByCond query.

llvm-svn: 75511
2009-07-13 21:35:55 +00:00
Owen Anderson 542619e6d5 Move more functionality over to LLVMContext.
llvm-svn: 75497
2009-07-13 20:58:05 +00:00
Dan Gohman 74a0ba15d3 Move the memoization check for SCEVSignExtendExpr and
SCEVZeroExtendExpr ahead of the most expensive analysis. This
speeds up analysis and helps avoid pathologically bad behavior
on the testcase in PR4534.

llvm-svn: 75496
2009-07-13 20:55:53 +00:00
Dan Gohman 3a302cbb08 Convert SCEV from FoldingSetNode to FastFoldingSetNode. This eliminates
a bunch of redundent code in Profile methods, and prepares for upcoming
changes to do improved memoization.

llvm-svn: 75494
2009-07-13 20:50:19 +00:00
Owen Anderson 53a52215b5 Begin the painful process of tearing apart the rat'ss nest that is Constants.cpp and ConstantFold.cpp.
This involves temporarily hard wiring some parts to use the global context.  This isn't ideal, but it's
the only way I could figure out to make this process vaguely incremental.

llvm-svn: 75445
2009-07-13 04:09:18 +00:00
Nick Lewycky c0bf46b226 Revert r75252 which was causing some crashes at compile time.
llvm-svn: 75384
2009-07-11 20:38:25 +00:00
Torok Edwin 56d0659726 assert(0) -> LLVM_UNREACHABLE.
Make llvm_unreachable take an optional string, thus moving the cerr<< out of
line.
LLVM_UNREACHABLE is now a simple wrapper that makes the message go away for
NDEBUG builds.

llvm-svn: 75379
2009-07-11 20:10:48 +00:00
Dan Gohman 028e6158c2 Remove ScalarEvolution::hasSCEV, which isn't being used, and which
breaks encapsulation. Also remove a dead prototype for setSCEV.

llvm-svn: 75272
2009-07-10 20:25:29 +00:00
Dan Gohman a9938d8226 Generalize ScalarEvolution's cast-folding code to support more kinds
of loops. Add several new functions to for working with ScalarEvolution's
add-hoc value-range analysis functionality.

llvm-svn: 75252
2009-07-10 16:42:52 +00:00
Dan Gohman dc19104267 Make the code that updates ScalarEvolution's internal state in response
to a loop deletion more thorough. Don't prune the def-use tree search at
instructions that don't have SCEVs computed, because an instruction with
a user that has a computed SCEV may itself lack a computed SCEV.  Also,
remove loop-related values from the ValuesAtScopes and
ConstantEvolutionLoopExitValues maps as well.

This fixes a regression in 483.xalancbmk.

llvm-svn: 75030
2009-07-08 19:23:34 +00:00
Dan Gohman af75234955 Change all SCEV* to SCEV *.
llvm-svn: 74918
2009-07-07 17:06:11 +00:00
Owen Anderson 38264b1554 "LLVMContext* " --> "LLVMContext *"
llvm-svn: 74878
2009-07-06 23:00:19 +00:00
Owen Anderson f1f1743b2e Finish LLVMContext-ing lib/Analysis. This required pushing LLVMContext's through the ValueTracking API.
llvm-svn: 74873
2009-07-06 22:37:39 +00:00
Owen Anderson 39f00cc1d4 Thread LLVMContext through the constant folding APIs, which touches a lot of files.
llvm-svn: 74844
2009-07-06 18:42:36 +00:00
Nick Lewycky 3292908132 When comparing constants, consider a less wide constant to be "less complex"
than a wider one, before trying to compare their contents which will crash
if their sizes are different.

llvm-svn: 74792
2009-07-04 17:24:52 +00:00
Dan Gohman 3423e72b55 Minor code cleanups.
llvm-svn: 74551
2009-06-30 20:13:32 +00:00
Dan Gohman 9d203c636b Use getSCEV instead of getUnknown to create a SCEV for a
Constant. This lets ConstantInts be handled as SCEVConstant instead
of SCEVUnknown, as getUnknown no longer has special-case code for
ConstantInt and friends. This usually doesn't affect the final
output, since the constants end up getting folded later, but it
does make intermediate expressions more obvious in many cases.

llvm-svn: 74459
2009-06-29 21:31:18 +00:00
Dan Gohman 19d2417c90 Don't cache PHI exit values from exhaustive evaluations, because
an individual exhaustive evaluation reflects only the exit value
implied by an individual exit, which may differ from the actual
exit value of the loop if there are other exits. This fixes PR4477.

llvm-svn: 74447
2009-06-29 20:34:13 +00:00
Dan Gohman e00beaaee8 Simplify this code, and avoid using APInt(). This fixes
(otherwise harmless) uninitialized value warnings that
Duncan found with gcc-4.4.

llvm-svn: 74437
2009-06-29 18:25:52 +00:00
Dan Gohman c5c85c0fec Convert ScalarEvolution to use BumpPtrAllocator and FoldingSet, instead
of a team of individual allocations and a team of std::maps.

llvm-svn: 74393
2009-06-27 21:21:31 +00:00
Dan Gohman cc030b7e51 Fix ScalarEvolution::getAddRecExpr's code which canonicalized the
nesting order of nested AddRec expressions to skip the transformation
if it would introduce an AddRec with operands not loop-invariant
with respect to its loop.

llvm-svn: 74343
2009-06-26 22:36:20 +00:00
Dan Gohman 06a4e273be Fix SCEVAddRecExpr::isLoopInvariant to test if all of its operands
are loop invariant, not just the start operand.

llvm-svn: 74338
2009-06-26 22:17:21 +00:00
Dan Gohman abd1709678 Minor whitespace cleanups.
llvm-svn: 74074
2009-06-24 14:49:00 +00:00
Dan Gohman f57bdb75d4 Simplify [su]max(MAX, n) to MAX. This comes up in loop tripcount
computations in loops with multiple exits.

Adjust the testcase for PR4436 so that the relevant portion isn't
optimized away.

llvm-svn: 74073
2009-06-24 14:46:22 +00:00
Dan Gohman ce973df28b Delete some orphaned comments, fix some 80-column violations,
and tidy up a few other formatting issues.

llvm-svn: 74060
2009-06-24 04:48:43 +00:00
Dan Gohman f19aeec3f5 Extend ScalarEvolution's multiple-exit support to compute exact
trip counts in more cases.

Generalize ScalarEvolution's isLoopGuardedByCond code to recognize
And and Or conditions, splitting the code out into an
isNecessaryCond helper function so that it can evaluate Ands and Ors
recursively, and make SCEVExpander be much more aggressive about
hoisting instructions out of loops.

test/CodeGen/X86/pr3495.ll has an additional instruction now, but
it appears to be due to an arbitrary register allocation difference.

llvm-svn: 74048
2009-06-24 01:18:18 +00:00
Dan Gohman d261d27165 Teach GetMinSignBits about SCEVAddExprs.
llvm-svn: 74045
2009-06-24 01:05:09 +00:00
Dan Gohman f436bacb6b Move the special cases for constants out of getUnknown and into
createSCEV. Also, recognize UndefValue in createSCEV.

Change getIntegerSCEV's comment to avoid mentioning FP types,
and re-implement it in terms of getConstant instead of getUnknown.

llvm-svn: 74041
2009-06-24 00:54:57 +00:00
Dan Gohman 8d7576e12c Use ScalarEvolution::getConstant instead of getUnknown to create
SCEVConstants. This cleanup is a step toward letting getUnknown
be simpler.

llvm-svn: 74037
2009-06-24 00:38:39 +00:00
Dan Gohman 6994293b17 Include the maximum trip count expression in ScalarEvolution's print output.
llvm-svn: 74035
2009-06-24 00:33:16 +00:00
Dan Gohman 18a96bb07f Add an isAllOnesValue utility function, similar to isZero and isOne.
llvm-svn: 74032
2009-06-24 00:30:26 +00:00
Dan Gohman 53efeb0e45 Fix a bug in the trip-count computation with And/Or. If either of the
sides is CouldNotCompute, the resulting exact count must be CouldNotCompute.

llvm-svn: 73920
2009-06-22 23:28:56 +00:00
Owen Anderson 04052ec597 Remove the parent pointer from SCEV, since it did not end up being needed.
llvm-svn: 73907
2009-06-22 21:57:23 +00:00
Owen Anderson 65b6056e37 SCEVHandle is no more!
llvm-svn: 73906
2009-06-22 21:39:50 +00:00
Dan Gohman 8885b379fa Fix some typos that Duncan noticed.
llvm-svn: 73903
2009-06-22 21:10:22 +00:00
Owen Anderson 86837616f7 Banish global state from ScalarEvolution! SCEV uniquing is now done by tables attached to the ScalarEvolution pass.
This also throws out the SCEV reference counting scheme, as the the SCEVs now have a lifetime controlled by the
ScalarEvolution pass.

Note that SCEVHandle is now a no-op, and will be remove in a future commit.

llvm-svn: 73892
2009-06-22 18:25:46 +00:00
Dan Gohman ed627385de Make use of getUMinFromMismatchedTypes when computing backedge-taken
counts for loops with multiple exits, replacing more conservative code
which only handled constants. This is derived from a patch by
Nick Lewycky.

This also fixes llc aborts in ClamAV and others, as
getUMinFromMismatchedTypes takes care of balancing the types before
working with them.

llvm-svn: 73884
2009-06-22 15:09:28 +00:00
Dan Gohman 2bc22305d2 Add a getUMinFromMismatchedTypes helper function.
llvm-svn: 73883
2009-06-22 15:03:27 +00:00
Dan Gohman 692b46872e Factor out code for computing umin and smin for SCEV expressions into
helper functions. Based on a patch by Nick Lewycky.

llvm-svn: 73869
2009-06-22 03:18:45 +00:00
Dan Gohman 96212b661c Teach ScalarEvolution how to analyze loops with multiple exit
blocks, and also exit blocks with multiple conditions (combined
with (bitwise) ands and ors). It's often infeasible to compute an
exact trip count in such cases, but a useful upper bound can often
be found.

llvm-svn: 73866
2009-06-22 00:31:57 +00:00
Dan Gohman 13037149b9 Delete an unused variable.
llvm-svn: 73865
2009-06-22 00:19:17 +00:00
Dan Gohman 0104842ee3 Fix ScalarEvolution's backedge-taken count computations to check for
overflow when computing a integer division to round up.

Thanks to Nick Lewycky for noticing this!

llvm-svn: 73862
2009-06-21 23:46:38 +00:00
Dan Gohman 450f4e0fa9 Generalize isLoopGuardedByCond's checking to consider two
SCEVUnknowns with identical Instructions to be equal. This allows
it to analze cases such as the attached testcase, where the front-end
has cloned the loop controlling expression. Along with r73805, this
lets IndVarSimplify eliminate all the sign-extend casts in the
loop in the attached testcase.

llvm-svn: 73807
2009-06-20 00:35:32 +00:00
Dan Gohman 90d612e536 Use ScalarEvolution's new GetMinSignBits and GetMinLeadingZeros
in the loop backedge-taken count computation of the maximum
possible trip count.

llvm-svn: 73805
2009-06-20 00:32:22 +00:00
Dan Gohman c702fc0e64 Make GetMinTrailingZeros a member function of ScalarEvolution,
so that it can access the TargetData member (when available) and
use ValueTracking.h information to compute information for
SCEVUnknown Values.

Also add GetMinLeadingZeros and GetMinSignBits functions,
with minimal implementations.

llvm-svn: 73794
2009-06-19 23:29:04 +00:00
Dan Gohman b9063a84ce Make ScalarEvolution::print print getSCEVAtScope values for
expressions, when interesting.

llvm-svn: 73776
2009-06-19 17:49:54 +00:00
Owen Anderson 38830b19e9 Add a parent pointer to SCEV, in preparation for getting rid of the global uniquing tables. No functionality change.
llvm-svn: 73728
2009-06-18 22:25:12 +00:00
Dan Gohman 4d3c3cfffd Recognize n != 0 ? n : 1 as umax(n, 1). Previously only ULT/UGT/ULE/UGE
comparisons were recognized for umax, but instcombine canonicalizes
unsigned comparisons with zero to this simpler form.

llvm-svn: 73717
2009-06-18 20:21:07 +00:00
Dan Gohman 5a728c908c Update a comment to reflect the code.
llvm-svn: 73704
2009-06-18 16:24:47 +00:00
Dan Gohman 94c468f419 Fix trailing whitespace from ScalarEvolution::print.
llvm-svn: 73666
2009-06-18 00:37:45 +00:00
Dan Gohman eddf77123a Teach ScalarEvolution how to recognize another xor(and(x, C), C) case.
If C is a single bit and the and gets analyzed as a truncate and
zero-extend, the xor can be represnted as an add.

llvm-svn: 73664
2009-06-18 00:00:20 +00:00
Dan Gohman 4d8723d47f Delete unnecessary braces.
llvm-svn: 73663
2009-06-17 23:54:37 +00:00
Dan Gohman b50f5a46e0 Fix ScalarEvolution's Xor handling to not assume that an And
that gets recognized with a SCEVZeroExtendExpr must be an And
with a low-bits mask. With r73540, this is no longer the case.

llvm-svn: 73594
2009-06-17 01:22:39 +00:00
Dan Gohman 1ee696d8fc Instcombine's ShrinkDemandedConstant may strip bits out of constants,
obscuring what would otherwise be a low-bits mask.  Use ComputeMaskedBits
to compute what ShrinkDemandedConstant knew about to reconstruct a
low-bits mask value.

llvm-svn: 73540
2009-06-16 19:52:01 +00:00
Dan Gohman 7ccc52f131 Support vector casts in more places, fixing a variety of assertion
failures.

To support this, add some utility functions to Type to help support
vector/scalar-independent code. Change ConstantInt::get and
ConstantFP::get to support vector types, and add an overload to
ConstantInt::get that uses a static IntegerType type, for
convenience.

Introduce a new getConstant method for ScalarEvolution, to simplify
common use cases.

llvm-svn: 73431
2009-06-15 22:12:54 +00:00
Dan Gohman 038d02e74e Implement more aggressive folding of add operand lists when
they contain multiplications of constants with add operations.
This helps simplify several kinds of things; in particular it
helps simplify expressions like ((-1 * (%a + %b)) + %a) to %b,
as expressions like this often come up in loop trip count
computations.

llvm-svn: 73361
2009-06-14 22:58:51 +00:00
Dan Gohman 011cf687d7 Check for the short-circuiting condition before performing
the potentially expensive erase.

llvm-svn: 73359
2009-06-14 22:53:57 +00:00
Dan Gohman 862b7d98d1 Do compare constant SCEV values in SCEVComplexityCompare, because
even though the order doesn't matter at the top level of an expression,
it does matter when the constant is a subexpression of an n-ary
expression, because n-ary expressions are sorted lexicographically.

llvm-svn: 73358
2009-06-14 22:51:25 +00:00
Dan Gohman 0652fd59ff Convert several parts of the ScalarEvolution framework to use
SmallVector instead of std::vector.

llvm-svn: 73357
2009-06-14 22:47:23 +00:00
Dan Gohman 8db2edcf7f Add a ScalarEvolution::getAnyExtendExpr utility function for performing
extension with unspecified bits.

llvm-svn: 73293
2009-06-13 15:56:47 +00:00
Dan Gohman 4c720c07bb Rename UnknownValue to CouldNotCompute, since it holds an instance of
SCEVCouldNotCompute, and not SCEVUnknown.

llvm-svn: 72999
2009-06-06 14:37:11 +00:00
Devang Patel afa8a1592f Simplify.
llvm-svn: 72970
2009-06-05 23:08:56 +00:00
Dan Gohman d9ef48a73e Remove some unnecessary #includes.
llvm-svn: 72948
2009-06-05 16:32:58 +00:00
Dan Gohman 2a6606ca20 For the return type of SCEVUDivExpr, use the RHS' type instead of
that of the LHS. It doesn't matter for correctness, but the LHS
is more likely than the RHS to be a pointer type in exotic cases,
and it's more tidy to have it return the integer type.

llvm-svn: 72424
2009-05-26 17:44:05 +00:00
Dan Gohman 4d5435d46a Various comment fixes.
llvm-svn: 72376
2009-05-24 23:45:28 +00:00
Dan Gohman 8ca0885d69 Change ScalarEvolution::getSCEVAtScope to always return the original value
in the case where a loop exit value cannot be computed, instead of only in
some cases while using SCEVCouldNotCompute in others. This simplifies
getSCEVAtScope's callers.

llvm-svn: 72375
2009-05-24 23:25:42 +00:00
Dan Gohman 9cbf850506 Teach SCEV::isLoopInvariant and SCEV::hasComputableLoopEvolution
about the convention from LoopInfo that a null Loop* means the entire
function body.

llvm-svn: 72152
2009-05-20 01:01:24 +00:00
Dan Gohman d33a090efa Make SCEVCallbackVH a private nested class inside ScalarEvolution, as
it's an implementation detail.

llvm-svn: 72122
2009-05-19 19:22:47 +00:00
Dan Gohman 2649491f9c 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.

llvm-svn: 72093
2009-05-19 02:15:55 +00:00