aboutsummaryrefslogtreecommitdiff
path: root/lib/Transforms/Scalar/IndVarSimplify.cpp
AgeCommit message (Collapse)Author
2009-07-09This started as a small change, I swear. Unfortunately, lots of things call ↵Owen Anderson
the [I|F]CmpInst constructors. Who knew!? git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75200 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-07Change all SCEV* to SCEV *.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74918 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-03Convert the first batch of passes to use LLVMContext.Owen Anderson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74748 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-01Request LCSSA after LoopSimplify. This fixes a problem in which theDan Gohman
PassManager was scheduling LCSSA before LoopSimplify, which does not preserve LCSSA. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74661 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-27When a value is used multiple times within a single PHI, instructionsDan Gohman
inserted to replace that value must dominate all of of the basic blocks associated with the uses of the value in the PHI, not just one of them. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74376 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-26Incorporate the insertion point into the key of SCEVExpander's CSE map.Dan Gohman
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
2009-06-24When inserting code into a loop preheader, insert it before theDan Gohman
terminator, instead of after the last phi. This fixes a bug exposed by ScalarEvolution analyzing more kinds of loops. This fixes PR4436. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74072 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-24Extend ScalarEvolution's multiple-exit support to compute exactDan Gohman
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
2009-06-22Fix a few minor issues that were exposed by the removal of SCEVHandle.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73910 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-22SCEVHandle is no more!Owen Anderson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73906 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-22Fix this code to correctly handle loops with multiple exits. UntilDan Gohman
now, this hasn't mattered, because ScalarEvolution hasn't been able to compute trip counts for loops with multiple exits. But it will soon. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73864 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-14Add another item to the list of things that indvars does.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73355 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-13Teach SCEVExpander's visitAddRecExpr to reuse an existing canonicalDan Gohman
induction variable when the addrec to be expanded does not require a wider type. This eliminates the need for IndVarSimplify to micro-manage SCEV expansions, because SCEVExpander now automatically expands them in the form that IndVarSimplify considers to be canonical. (LSR still micro-manages its SCEV expansions, because it's optimizing for the target, rather than for other optimizations.) Also, this uses the new getAnyExtendExpr, which has more clever expression simplification logic than the IndVarSimplify code it replaces, and this cleans up some ugly expansions in code such as the included masked-iv.ll testcase. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73294 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-04Split the Add, Sub, and Mul instruction opcodes into separateDan Gohman
integer and floating-point opcodes, introducing FAdd, FSub, and FMul. For now, the AsmParser, BitcodeReader, and IRBuilder all preserve backwards compatability, and the Core LLVM APIs preserve backwards compatibility for IR producers. Most front-ends won't need to change immediately. This implements the first step of the plan outlined here: http://nondot.org/sabre/LLVMNotes/IntegerOverflow.txt git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72897 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-03Don't attempt to simplify an non-affine IV expression if it can'tDan Gohman
be simplified to a loop-invariant value. This fixes PR4315. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72798 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-24Change ScalarEvolution::getSCEVAtScope to always return the original valueDan Gohman
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
2009-05-24Move Rewriter.clear() earlier, to avoid triggerring the AssertingVH byTorok Edwin
one of the RecursivelyDeleteTriviallyDeadInstructions. Add a comment explaining why the cache needs to be cleared. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72372 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-24Instead of clearing the rewriter, don't attempt to rewrite dead phi nodes.Torok Edwin
Also fix 80 column violation. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72371 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-24When rewriting the loop exit test with the canonical induction variable,Dan Gohman
leave the original comparison in place if it has other uses, since the other uses won't be dominated by the new comparison instruction. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72369 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-24When replacing a floating-point comparison with an integerDan Gohman
comparison, use takeName to give the integer comparison a name. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72367 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-24The rewriter may hold references to instructions that are deleted because ↵Torok Edwin
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
2009-05-22Teach IndVarSimplify's FixUsesBeforeDefs to handle InvokeInsts byDan Gohman
assuming that the use of the value is in a block dominated by the "normal" destination. LangRef.html and other documentation sources don't explicitly guarantee this, but it seems to be assumed in other places in LLVM at least. This fixes an assertion failure on the included testcase, which is derived from the Ada testsuite. FixUsesBeforeDefs is a temporary measure which I'm looking to replace with a more capable solution. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72266 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-19Remove an irrelevant comment.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72132 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-19Trim unneeded #includes.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72130 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-19Teach SCEVExpander to expand arithmetic involving pointers into GEPDan Gohman
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
2009-05-14Use abs64 in one more place.Dale Johannesen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71775 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-12Factor the code for collecting IV users out of LSR into an IVUsers class,Dan Gohman
and generalize it so that it can be used by IndVarSimplify. Implement the base IndVarSimplify transformation code using IVUsers. This removes TestOrigIVForWrap and associated code, as ScalarEvolution now has enough builtin overflow detection and folding logic to handle all the same cases, and more. Run "opt -iv-users -analyze -disable-output" on your favorite loop for an example of what IVUsers does. This lets IndVarSimplify eliminate IV casts and compute trip counts in more cases. Also, this happens to finally fix the remaining testcases in PR1301. Now that IndVarSimplify is being more aggressive, it occasionally runs into the problem where ScalarEvolutionExpander's code for avoiding duplicate expansions makes it difficult to ensure that all expanded instructions dominate all the instructions that will use them. As a temporary measure, IndVarSimplify now uses a FixUsesBeforeDefs function to fix up instructions inserted by SCEVExpander. Fortunately, this code is contained, and can be easily removed once a more comprehensive solution is available. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71535 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-04Re-apply 70645, converting ScalarEvolution to useDan Gohman
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
2009-05-03Revert r70645 for now; it's causing a variety of regressions.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70661 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-02Convert ScalarEvolution to use CallbackVH for its internal map. ThisDan Gohman
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
2009-04-27Remove an obsolete comment.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70262 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-27Fix PR 4086, a bug in FP IV elimination.Dale Johannesen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70247 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-23Change SCEVExpander's expandCodeFor to provide more flexibilityDan Gohman
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
2009-04-22Make sure both operands have binary instructions have the same type.Evan Cheng
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69844 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-22A few more places where the check of use_empty is needed.Evan Cheng
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69842 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-22Avoid deferencing use_begin() if value does not have a use.Evan Cheng
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69836 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-21Introduce encapsulation for ScalarEvolution's TargetData object, and refactorDan Gohman
the code to minimize dependencies on TargetData. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69644 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-18Use more const qualifiers with SCEV interfaces.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69450 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-16Expand GEPs in ScalarEvolution expressions. SCEV expressions can nowDan Gohman
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
2009-04-15Eliminate zext over (iv | const) or (signed iv),Dale Johannesen
and sext over (iv | const), if a longer iv is available. Allow expressions to have more than one zext/sext parent. All from OpenSSL. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69241 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-15Eliminate zext over (iv & const) or ((iv+const)&const)Dale Johannesen
if a longer iv is available. These subscript forms are not common; they're a bottleneck in OpenSSL. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69215 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-15Enhance induction variable code to remove theDale Johannesen
sext around sext(shorter IV + constant), using a longer IV instead, when it can figure out the add can't overflow. This comes up a lot in subscripting; mainly affects 64 bit. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69123 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-24Rename ScalarEvolution's getIterationCount to getBackedgeTakenCount,Dan Gohman
to more accurately describe what it does. Expand its doxygen comment to describe what the backedge-taken count is and how it differs from the actual iteration count of the loop. Adjust names and comments in associated code accordingly. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@65382 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-23Back out the change in 64918 that used sign-extensions when promotingDan Gohman
trip counts that use signed comparisons. It's not obviously the best approach for preserving trip count information, and at any rate there isn't anything in the tree right now that makes use of that, so for now always using zero-extensions is preferable. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@65347 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-23IndVarSimplify preserves ScalarEvolution. In theDan Gohman
-std-compile-opts sequence, this avoids the need for ScalarEvolution to be rerun before LoopDeletion. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@65318 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-18Use a sign-extend instead of a zero-extend when promoting aDan Gohman
trip count value when the original loop iteration condition is signed and the canonical induction variable won't undergo signed overflow. This isn't required for correctness; it just preserves more information about original loop iteration values. Add a getTruncateOrSignExtend method to ScalarEvolution, following getTruncateOrZeroExtend. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64918 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-18Simplify by using dyn_cast instead of isa and cast.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64917 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-18Fix a corner case in the new indvars promotion logic: if thereDan Gohman
are multiple IV's in a loop, some of them may under go signed or unsigned wrapping even if the IV that's used in the loop exit condition doesn't. Restrict sign-extension-elimination and zero-extension-elimination to only those that operate on the original loop-controlling IV. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64866 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-17Add a method to ScalarEvolution for telling it when a loop has beenDan Gohman
modified in a way that may effect the trip count calculation. Change IndVars to use this method when it rewrites pointer or floating-point induction variables instead of using a doInitialization method to sneak these changes in before ScalarEvolution has a chance to see the loop. This eliminates the need for LoopPass to depend on ScalarEvolution. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64810 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-17Delete trailing whitespace.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64784 91177308-0d34-0410-b5e6-96231b3b80d8