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path: root/lib/Transforms/Scalar/LoopStrengthReduce.cpp
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2010-05-07When pruning candidate formulae out of an LSRUse, update theDan Gohman
LSRUse's Regs set after all pruning is done, rather than trying to do it on the fly, which can produce an incomplete result. This fixes a case where heuristic pruning was stripping all formulae from a use, which led the solver to enter an infinite loop. Also, add a few asserts to diagnose this kind of situation. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@103328 91177308-0d34-0410-b5e6-96231b3b80d8
2010-05-03Use getConstant instead of getIntegerSCEV. The two are basically theDan Gohman
same, now that getConstant has overloads consistent with ConstantInt::get. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@102965 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-24Generalize LSR's OptimizeMax to handle the new kinds of max expressionsDan Gohman
that indvars may use, now that indvars is recognizing le and ge loops. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@102235 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-23Fix LSR to tolerate cases where ScalarEvolution initiallyDan Gohman
misses an opportunity to fold add operands, but folds them after LSR has separated them out. This fixes rdar://7886751. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@102157 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-19Remove the Expr member from IVUsers. Instead of remembering the expression,Dan Gohman
just ask ScalarEvolution for it on demand. This helps IVUsers be more robust in the case of expressions changing underneath it. This fixes PR6862. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101819 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-12Delete this code, which is no longer needed.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101033 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-09When determining a canonical insert position, don't climb deeperDan Gohman
into adjacent loops. Also, ensure that the insert position is dominated by the loop latch of any loop in the post-inc set which has a latch. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100906 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-09When looking for loop-invariant users, look through no-op instructions,Dan Gohman
so that an unfortunately placed bitcast doesn't pin a value in a register. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100883 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-09Refactor the code for computing the insertion point for an expression intoDan Gohman
a separate function. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100845 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-08Avoid allocating a value of zero in a register if the initial formulaDan Gohman
inputs happen to negate each other. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100828 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-08Add variants of ult, ule, etc. which take a uint64_t RHS, for convenience.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100824 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-08When expanding expressions which are using post-inc mode for multiple loops,Dan Gohman
ensure that the expansion is dominated by the increments of those loops. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100748 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-07Generalize IVUsers to track arbitrary expressions rather than expressionsDan Gohman
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
2010-03-26Ignore debug intrinsics in yet more places.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99580 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-25rename use_const_iterator to const_use_iterator for consistency's sakeGabor Greif
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99564 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-03Make SCEVExpander and LSR more aggressive about hoisting expressions outDan Gohman
of loops. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97642 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-02Non-affine post-inc SCEV expansions have more code which must beDan Gohman
emitted after the increment. Make sure the insert position reflects this. This fixes PR6453. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97537 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-01Spelling fixes.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97453 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-22Remove unused variables and parameters.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96780 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-22When emitting an instruction which depends on both a post-incrementedDan Gohman
induction variable value and a loop-variant value, don't force the insert position to be at the post-increment position, because it may not be dominated by the loop-variant value. This fixes a use-before-def problem noticed on PPC. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96774 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-19Rename getSDiv to getExactSDiv to reflect its behavior in cases whereDan Gohman
the division would have a remainder. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96693 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-19Check for overflow when scaling up an add or an addrec forDan Gohman
scaled reuse. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96692 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-19When determining the set of interesting reuse factors, considerDan Gohman
strides in foreign loops. This helps locate reuse opportunities with existing induction variables in foreign loops and reduces the need for inserting new ones. This fixes rdar://7657764. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96629 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-17Delete some unneeded casts.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96429 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-17Don't attempt to divide INT_MIN by -1; consider such cases toDan Gohman
have overflowed. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96428 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-16Refactor rewriting for PHI nodes into a separate function.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96382 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-16Fix whitespace.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96372 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-16There are two ways of checking for a given type, for example isa<PointerType>(T)Duncan Sands
and T->isPointerTy(). Convert most instances of the first form to the second form. Requested by Chris. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96344 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-16Split the main for-each-use loop again, this time for GenerateTruncates,Dan Gohman
as it also peeks at which registers are being used by other uses. This makes LSR less sensitive to use-list order. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96308 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-14Fix whitespace.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96179 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-14Fix a comment.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96178 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-14When complicated expressions are broken down into subexpressionsDan Gohman
with multiplication by constants distributed through, occasionally those subexpressions can include both x and -x. For now, if this condition is discovered within LSR, just prune such cases away, as they won't be profitable. This fixes a "zero allocated in a base register" assertion failure. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96177 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-14Actually, this code doesn't have to be quite so conservative inDan Gohman
the no-TLI case. But it should still default to declining the transformation. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96152 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-14Don't attempt aggressive post-inc uses if TargetLowering is not available,Dan Gohman
because profitability can't be sufficiently approximated. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96148 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-13Make LSR not crash if invoked without target lowering info, e.g. if invokedJohn McCall
from opt. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96135 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-13Fix a pruning heuristic which implicitly assumed that SmallPtrSet isDan Gohman
deterministically sorted. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96071 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-12Reapply 95979, a compile-time speedup, now that the bug it exposed is fixed.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96005 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-12Fix this code to avoid dereferencing an end() iterator inDan Gohman
offset distributions it doesn't expect. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96002 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-12Revert "Reverse the order for collecting the parts of an addrec. The order", itDaniel Dunbar
is breaking llvm-gcc bootstrap. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95988 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-12Reverse the order for collecting the parts of an addrec. The orderDan Gohman
doesn't matter, except that ScalarEvolution tends to need less time to fold the results this way. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95979 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-12Reapply the new LoopStrengthReduction code, with compile time andDan Gohman
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
2010-01-29Generic reformatting and comment fixing. No functionality change.Bill Wendling
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94771 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-29Add newline to debugging output, and fix some grammar-os in comment.Bill Wendling
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94765 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-22Revert LoopStrengthReduce.cpp to pre-r94061 for now.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94123 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-21When inserting expressions for post-increment users which containDan Gohman
loop-variant components, adds must be inserted after the increment. Keep track of the increment position for this case, and insert these adds in the correct location. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94110 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-21Include IVUsers information in LSR's debug output.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94108 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-21Prune the search for candidate formulae if the number of registerDan Gohman
operands exceeds the number of registers used in the initial solution, as that wouldn't lead to a profitable solution anyway. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94107 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-21Add a comment.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94104 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-21Re-implement the main strength-reduction portion of LoopStrengthReduction.Dan Gohman
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
2010-01-05Set Changed properly after calling DeleteDeadPHIs.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92735 91177308-0d34-0410-b5e6-96231b3b80d8