Commit Graph

338 Commits

Author SHA1 Message Date
Dan Gohman
69fbc7f477 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75496 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-13 20:55:53 +00:00
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