Commit Graph

387 Commits

Author SHA1 Message Date
Dan Gohman
c050fd94c2 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75494 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-13 20:50:19 +00:00
Owen Anderson
0a5372ed3e 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75445 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-13 04:09:18 +00:00
Nick Lewycky
d0cca24150 Revert r75252 which was causing some crashes at compile time.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75384 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-11 20:38:25 +00:00
Torok Edwin
c25e7581b9 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75379 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-11 20:10:48 +00:00
Dan Gohman
1afdc5f356 Remove ScalarEvolution::hasSCEV, which isn't being used, and which
breaks encapsulation. Also remove a dead prototype for setSCEV.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75272 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-10 20:25:29 +00:00
Dan Gohman
1b342583f6 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75252 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-10 16:42:52 +00:00
Dan Gohman
59ae6b9987 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75030 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-08 19:23:34 +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
07cf79ef53 "LLVMContext* " --> "LLVMContext *"
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74878 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-06 23:00:19 +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
Nick Lewycky
d1ec98923e 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74792 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-04 17:24:52 +00:00
Dan Gohman
c39f44b521 Minor code cleanups.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74551 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-30 20:13:32 +00:00
Dan Gohman
099879687f 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74459 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-29 21:31:18 +00:00
Dan Gohman
cffddcd726 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74447 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-29 20:34:13 +00:00
Dan Gohman
23737e0423 Simplify this code, and avoid using APInt(). This fixes
(otherwise harmless) uninitialized value warnings that
Duncan found with gcc-4.4.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74437 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-29 18:25:52 +00:00
Dan Gohman
1c34375f79 Convert ScalarEvolution to use BumpPtrAllocator and FoldingSet, instead
of a team of individual allocations and a team of std::maps.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74393 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-27 21:21:31 +00:00
Dan Gohman
9a80b459ed 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74343 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-26 22:36:20 +00:00
Dan Gohman
e890eead22 Fix SCEVAddRecExpr::isLoopInvariant to test if all of its operands
are loop invariant, not just the start operand.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74338 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-26 22:17:21 +00:00
Dan Gohman
9311ef6a91 Minor whitespace cleanups.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74074 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-24 14:49:00 +00:00
Dan Gohman
e5aceed168 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74073 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-24 14:46:22 +00:00
Dan Gohman
64a845e836 Delete some orphaned comments, fix some 80-column violations,
and tidy up a few other formatting issues.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74060 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-24 04:48:43 +00:00
Dan Gohman
40a5a1b39e 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74048 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-24 01:18:18 +00:00
Dan Gohman
62849c065e Teach GetMinSignBits about SCEVAddExprs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74045 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-24 01:05:09 +00:00
Dan Gohman
6bbcba18db 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74041 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-24 00:54:57 +00:00
Dan Gohman
b8be8b70a2 Use ScalarEvolution::getConstant instead of getUnknown to create
SCEVConstants. This cleanup is a step toward letting getUnknown
be simpler.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74037 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-24 00:38:39 +00:00
Dan Gohman
aa551ae10e Include the maximum trip count expression in ScalarEvolution's print output.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74035 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-24 00:33:16 +00:00
Dan Gohman
4d289bf4af Add an isAllOnesValue utility function, similar to isZero and isOne.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74032 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-24 00:30:26 +00:00
Dan Gohman
91380b7239 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73920 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-22 23:28:56 +00:00
Owen Anderson
753ad615f9 Remove the parent pointer from SCEV, since it did not end up being needed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73907 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-22 21:57:23 +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
d32f5bf22d Fix some typos that Duncan noticed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73903 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-22 21:10:22 +00:00
Owen Anderson
08367b6163 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73892 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-22 18:25:46 +00:00
Dan Gohman
60e9b0708a 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73884 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-22 15:09:28 +00:00
Dan Gohman
c9759e80f4 Add a getUMinFromMismatchedTypes helper function.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73883 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-22 15:03:27 +00:00
Dan Gohman
f9a9a9928c Factor out code for computing umin and smin for SCEV expressions into
helper functions. Based on a patch by Nick Lewycky.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73869 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-22 03:18:45 +00:00
Dan Gohman
a334aa7a10 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73866 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-22 00:31:57 +00:00
Dan Gohman
743ab498d8 Delete an unused variable.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73865 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-22 00:19:17 +00:00
Dan Gohman
51f53b7f5a 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!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73862 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-21 23:46:38 +00:00
Dan Gohman
763bad1a2b 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73807 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-20 00:35:32 +00:00
Dan Gohman
3964acc2f4 Use ScalarEvolution's new GetMinSignBits and GetMinLeadingZeros
in the loop backedge-taken count computation of the maximum
possible trip count.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73805 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-20 00:32:22 +00:00
Dan Gohman
2c364ad4a6 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73794 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-19 23:29:04 +00:00
Dan Gohman
0c689c5e05 Make ScalarEvolution::print print getSCEVAtScope values for
expressions, when interesting.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73776 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-19 17:49:54 +00:00
Owen Anderson
4a7893b452 Add a parent pointer to SCEV, in preparation for getting rid of the global uniquing tables. No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73728 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-18 22:25:12 +00:00
Dan Gohman
30fb512e95 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73717 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-18 20:21:07 +00:00
Dan Gohman
6864db6fac Update a comment to reflect the code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73704 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-18 16:24:47 +00:00
Dan Gohman
9e7d9883b0 Fix trailing whitespace from ScalarEvolution::print.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73666 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-18 00:37:45 +00:00
Dan Gohman
820528331f 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73664 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-18 00:00:20 +00:00
Dan Gohman
fc3641b07a Delete unnecessary braces.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73663 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-17 23:54:37 +00:00
Dan Gohman
3034c10675 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73594 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-17 01:22:39 +00:00
Dan Gohman
61ffa8e373 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73540 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-16 19:52:01 +00:00
Dan Gohman
6de29f8d96 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73431 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-15 22:12:54 +00:00
Dan Gohman
bd59d7b603 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73361 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-14 22:58:51 +00:00
Dan Gohman
7f7c4366ca Check for the short-circuiting condition before performing
the potentially expensive erase.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73359 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-14 22:53:57 +00:00
Dan Gohman
4dfad29547 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73358 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-14 22:51:25 +00:00
Dan Gohman
a82752c9eb Convert several parts of the ScalarEvolution framework to use
SmallVector instead of std::vector.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73357 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-14 22:47:23 +00:00
Dan Gohman
2ce84c8d47 Add a ScalarEvolution::getAnyExtendExpr utility function for performing
extension with unspecified bits.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73293 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-13 15:56:47 +00:00
Dan Gohman
86fbf2fe4c Rename UnknownValue to CouldNotCompute, since it holds an instance of
SCEVCouldNotCompute, and not SCEVUnknown.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72999 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-06 14:37:11 +00:00
Devang Patel
5c06f61e57 Simplify.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72970 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-05 23:08:56 +00:00
Dan Gohman
c965ee223c Remove some unnecessary #includes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72948 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-05 16:32:58 +00:00
Dan Gohman
91bb61a1e2 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72424 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-26 17:44:05 +00:00
Dan Gohman
6c0866ca83 Various comment fixes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72376 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-24 23:45:28 +00:00
Dan Gohman
d594e6f034 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72375 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-24 23:25:42 +00:00
Dan Gohman
a3035a69f9 Teach SCEV::isLoopInvariant and SCEV::hasComputableLoopEvolution
about the convention from LoopInfo that a null Loop* means the entire
function body.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72152 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-20 01:01:24 +00:00
Dan Gohman
1959b7562e Make SCEVCallbackVH a private nested class inside ScalarEvolution, as
it's an implementation detail.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72122 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-19 19:22:47 +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
Daniel Dunbar
8c562e2d25 Silence Release-Asserts warnings.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72011 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-18 16:43:04 +00:00
Dan Gohman
10978bd591 Teach ScalarEvolution to recognize x^-1 in the case where non-demanded
bits have been stripped out by instcombine.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72010 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-18 16:29:04 +00:00
Dan Gohman
0bac95e2e2 Delete a redundant 'else'.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72009 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-18 16:17:44 +00:00
Dan Gohman
8ea94524ed Fix ScalarEvolution::isLoopGuardedByCond to accept a null Loop*, for
consistency with other routines that use a null Loop* to mean code
not contained by any loop.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72008 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-18 16:03:58 +00:00
Dan Gohman
5183caebc1 Minor code cleanups. Do more of the work before the if statements
instead of within their controlling expressions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72007 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-18 15:58:39 +00:00
Dan Gohman
f78a978d46 Add assertion checks to the SCEV operator creation methods to catch
type mismatches.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72006 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-18 15:44:58 +00:00
Dan Gohman
859b4824ee Make ScalarEvolution::isLoopGuardedByCond work even when the edge
entering a loop is a non-split critical edge.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72004 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-18 15:36:09 +00:00
Dan Gohman
70a1fe7048 Add an isOne() utility function to ScalarEvolution, similar to isZero()
and similar to ConstantInt's isOne().


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72003 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-18 15:22:39 +00:00
Dan Gohman
467c430316 Add three new helper routines, getNoopOrZeroExtend,
getNoopOrSignExtend, and getTruncateOrNoop. These are similar
to getTruncateOrZeroExtend etc., except that they assert that
the conversion is either not widening or narrowing, as
appropriate. These will be used in some upcoming fixes.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71632 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-13 03:46:30 +00:00
Dan Gohman
efb9fbfdab When forgetting SCEVs for loop PHIs, don't forget SCEVUnknown values.
These values aren't analyzable, so they don't care if more information
about the loop trip count can be had. Also, SCEVUnknown is used for
a PHI while the PHI itself is being analyzed, so it needs to be left
in the Scalars map. This fixes a variety of subtle issues.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71533 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-12 01:27:58 +00:00
Dan Gohman
42a5875e10 Fix GetMinTrailingZeros for SCEVSignExtend and SCEVZeroExtendExpr to
return the correct value when the cast operand is all zeros. This ought
to be pretty rare, because it would mean that the regular SCEV folding
routines missed a case, though there are cases they might legitimately
miss. Also, it's unlikely anything currently using GetMinTrailingZeros
cares about this case.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71532 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-12 01:23:18 +00:00
Eli Friedman
361e54d433 Allow scalar evolution to compute iteration counts for loops with a
pointer-based condition.  This fixes PR3171.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71354 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-09 12:32:42 +00:00
Duncan Sands
777d2306b3 Rename PaddedSize to AllocSize, in the hope that this
will make it more obvious what it represents, and stop
it being confused with the StoreSize.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71349 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-09 07:06:46 +00:00
Dan Gohman
c63a62735b Don't attempt to handle unsized types in ScalarEvolution's GEP analyzer.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71302 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-09 00:14:52 +00:00
Dan Gohman
b0285932ab Fix bogus overflow checks by replacing them with actual
overflow checks.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71284 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-08 23:11:16 +00:00
Dan Gohman
728c7f3059 Fold trunc casts into add-recurrence expressions, allowing the
add-recurrence to be exposed. Add a new SCEV folding rule to
help simplify expressions in the presence of these extra truncs.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71264 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-08 21:03:19 +00:00
Dan Gohman
fb79160811 Fix another bug in r71252. This code supports GetElementPtr
constant exprs as well as instructions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71262 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-08 20:58:38 +00:00
Dan Gohman
6bce643c36 Add memoization for getSCEVAtScope results for instructions
which are not analyzed with SCEV techniques, which can require
brute-forcing through a large number of instructions. This
fixes a massive compile-time issue on 400.perlbench (in
particular, the loop in MD5Transform).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71259 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-08 20:47:27 +00:00
Dan Gohman
66a7e857aa Make the SCEV* form of getSCEVAtScope public, to allow ScalarEvolution
clients to use it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71258 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-08 20:38:54 +00:00
Dan Gohman
e810b0d430 Fix an error from r71252.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71255 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-08 20:36:47 +00:00
Dan Gohman
26466c0eb3 Factor out the code for creating SCEVs for GEPs into a
separate function.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71252 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-08 20:26:55 +00:00
Dan Gohman
185cf0395c Implement several new SCEV folding rules for UDiv SCEVs.
This fixes an old FIXME, and is needed by some upcoming changes.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71247 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-08 20:18:49 +00:00
Dan Gohman
a6b35e201f SCEVComplexityCompare's new code was missing SCEVUDivExpr. Implement
the SCEVUDivExpr case.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71173 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-07 19:23:21 +00:00
Dan Gohman
72861308d5 Make ScalarEvolution's GroupByComplexity more thorough. In addition
to sorting SCEVs by their kind, sort SCEVs of the same kind according
to their operands. This helps avoid things like (a+b) being a distinct
expression from (b+a).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71160 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-07 14:39:04 +00:00
Dan Gohman
6ee2f3d840 Trim unnecessary headers. Code in Analysis shouldn't use Transforms
headers due to library dependencies.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71159 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-07 14:30:26 +00:00
Dan Gohman
ecb403a9d3 Factor out a common base class between SCEVCommutativeExpr and
SCEVAddRecExpr. This eliminates redundant code for visiting
all the operands of an expression.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71157 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-07 14:00:19 +00:00
Dan Gohman
0a8eb57c3d Use stable_sort instead of plain sort to avoid the risk of generating
trivially different code on different hosts (due to differing
std::sort implementations).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71124 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-06 22:54:33 +00:00
Dan Gohman
35738ac150 Re-apply 70645, converting ScalarEvolution to use
CallbackVH, with fixes. allUsesReplacedWith need to
walk the def-use chains and invalidate all users of a
value that is replaced. SCEVs of users need to be
recalcualted even if the new value is equivalent. Also,
make forgetLoopPHIs walk def-use chains, since any
SCEV that depends on a PHI should be recalculated when
more information about that PHI becomes available.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70927 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-04 22:30:44 +00:00
Dan Gohman
bf2176a000 Fix an 80-column violation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70925 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-04 22:23:18 +00:00
Dan Gohman
92fa56eb58 Fix doxygen comment syntax.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70924 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-04 22:20:30 +00:00
Dan Gohman
622ed671b9 Constify a bunch of SCEV-using code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70919 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-04 22:02:23 +00:00
Dan Gohman
f9a77b77c2 Revert r70645 for now; it's causing a variety of regressions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70661 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-03 05:46:20 +00:00
Dan Gohman
db6fa29641 Convert ScalarEvolution to use CallbackVH for its internal map. This
makes ScalarEvolution::deleteValueFromRecords, and it's code that
subtly needed to be called before ReplaceAllUsesWith, unnecessary.

It also makes ValueDeletionListener unnecessary.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70645 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-02 21:19:20 +00:00
Dan Gohman
fb7d35f22a When ScalarEvolution is told to forget the trip count for a loop, have
it also forget any SCEVs associated with loop-header PHIs in the loop,
as they may be dependent on trip count information.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70633 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-02 17:43:35 +00:00