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path: root/lib/Transforms/Utils/SimplifyCFG.cpp
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2012-03-11llvm::SwitchInstStepan Dyatkovskiy
Renamed methods caseBegin, caseEnd and caseDefault with case_begin, case_end, and case_default. Added some notes relative to case iterators. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152532 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-08Taken into account Duncan's comments for r149481 dated by 2nd Feb 2012:Stepan Dyatkovskiy
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20120130/136146.html Implemented CaseIterator and it solves almost all described issues: we don't need to mix operand/case/successor indexing anymore. Base iterator class is implemented as a template since it may be initialized either from "const SwitchInst*" or from "SwitchInst*". ConstCaseIt is just a read-only iterator. CaseIt is read-write iterator; it allows to change case successor and case value. Usage of iterator allows totally remove resolveXXXX methods. All indexing convertions done automatically inside the iterator's getters. Main way of iterator usage looks like this: SwitchInst *SI = ... // intialize it somehow for (SwitchInst::CaseIt i = SI->caseBegin(), e = SI->caseEnd(); i != e; ++i) { BasicBlock *BB = i.getCaseSuccessor(); ConstantInt *V = i.getCaseValue(); // Do something. } If you want to convert case number to TerminatorInst successor index, just use getSuccessorIndex iterator's method. If you want initialize iterator from TerminatorInst successor index, use CaseIt::fromSuccessorIndex(...) method. There are also related changes in llvm-clients: klee and clang. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152297 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-06[unwind removal] We no longer have 'unwind' instructions being generated, soBill Wendling
remove the code that handles them. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149901 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-01SwitchInst refactoring.Stepan Dyatkovskiy
The purpose of refactoring is to hide operand roles from SwitchInst user (programmer). If you want to play with operands directly, probably you will need lower level methods than SwitchInst ones (TerminatorInst or may be User). After this patch we can reorganize SwitchInst operands and successors as we want. What was done: 1. Changed semantics of index inside the getCaseValue method: getCaseValue(0) means "get first case", not a condition. Use getCondition() if you want to resolve the condition. I propose don't mix SwitchInst case indexing with low level indexing (TI successors indexing, User's operands indexing), since it may be dangerous. 2. By the same reason findCaseValue(ConstantInt*) returns actual number of case value. 0 means first case, not default. If there is no case with given value, ErrorIndex will returned. 3. Added getCaseSuccessor method. I propose to avoid usage of TerminatorInst::getSuccessor if you want to resolve case successor BB. Use getCaseSuccessor instead, since internal SwitchInst organization of operands/successors is hidden and may be changed in any moment. 4. Added resolveSuccessorIndex and resolveCaseIndex. The main purpose of these methods is to see how case successors are really mapped in TerminatorInst. 4.1 "resolveSuccessorIndex" was created if you need to level down from SwitchInst to TerminatorInst. It returns TerminatorInst's successor index for given case successor. 4.2 "resolveCaseIndex" converts low level successors index to case index that curresponds to the given successor. Note: There are also related compatability fix patches for dragonegg, klee, llvm-gcc-4.0, llvm-gcc-4.2, safecode, clang. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149481 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-25Gracefully degrade precision in branch probability numbers.Nick Lewycky
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@148946 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-19Actually, this code handles wrapped sets just fine. Noticed by inspection.Nick Lewycky
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@148487 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-05Fix SpeculativelyExecuteBB to either speculate all or none of the phisDan Gohman
present in the bottom of the CFG triangle, as the transformation isn't ever valuable if the branch can't be eliminated. Also, unify some heuristics between SimplifyCFG's multiple if-converters, for consistency. This fixes rdar://10627242. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147630 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-05Revert r56315. When the instruction to speculate is a load, thisDan Gohman
code can incorrectly move the load across a store. This never happens in practice today, but only because the current heuristics accidentally preclude it. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147623 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-28Demystify this comment.Nick Lewycky
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147307 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-27Use false not zero, as a bool.Nick Lewycky
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147292 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-27Teach simplifycfg to recompute branch weights when merging some branches, andNick Lewycky
to discard weights when appropriate. Still more to do (and a new TODO), but it's a start! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147286 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-26Update the branch weight metadata when reversing the order of a branch.Nick Lewycky
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147280 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-26Sort includes, canonicalize whitespace, fix typos. No functionality change.Nick Lewycky
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147279 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-21Make some intrinsics safe to speculatively execute.Nick Lewycky
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147036 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-17Revert r146822 at Pete Cooper's request as it broke clang self hosting.Kevin Enderby
Hope I did this correctly :) git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146834 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-17SimplifyCFG now predicts some conditional branches to true or false ↵Pete Cooper
depending on previous branch on same comparison operands. For example, if (a == b) { if (a > b) // this is false Fixes some of the issues on <rdar://problem/10554090> git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146822 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-14Move Instruction::isSafeToSpeculativelyExecute out of VMCore andDan Gohman
into Analysis as a standalone function, since there's no need for it to be in VMCore. Also, update it to use isKnownNonZero and other goodies available in Analysis, making it more precise, enabling more aggressive optimization. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146610 91177308-0d34-0410-b5e6-96231b3b80d8
2011-09-05Delete trivial landing pads that just continue unwinding the caughtDuncan Sands
exception. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139117 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-26Address review comments.Benjamin Kramer
- Reword comments. - Allow undefined behavior interfering with undefined behavior. - Add address space checks. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@138619 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-26SimplifyCFG: If we have a PHI node that can evaluate to NULL and do a load ↵Benjamin Kramer
or store to the address returned by the PHI node then we can consider this incoming value as dead and remove the edge pointing there, unless there are instructions that can affect control flow executed in between. In theory this could be extended to other instructions, eg. division by zero, but it's likely that it will "miscompile" some code because people depend on div by zero not trapping. NULL pointer dereference usually leads to a crash so we should be on the safe side. This shrinks the size of a Release clang by 16k on x86_64. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@138618 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-16I think there was some confusion about what I meant. :-) Replacing the comment.Bill Wendling
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137743 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-16After talking with Bill, it seems like the LandingPad handling here is likelyEli Friedman
to be wrong (or at least somewhat suspect). Leave a FIXME for Bill. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137694 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-16Minor comment fixes.Eli Friedman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137693 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-15Update SimplifyCFG for atomic operations.Eli Friedman
This commit includes a mention of the landingpad instruction, but it's not changing the behavior around it. I think the current behavior is correct, though. Bill, can you double-check that? git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137691 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-18land David Blaikie's patch to de-constify Type, with a few tweaks.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135375 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-15Convert CallInst and InvokeInst APIs to use ArrayRef.Jay Foad
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135265 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-30Add r134057 back, but splice the predecessor after the successors phiRafael Espindola
nodes. Original message: Let simplify cfg simplify bb with only debug and lifetime intrinsics. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134182 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-29Temporarily revert r134057: "Let simplify cfg simplify bb with only debug and Chad Rosier
lifetime intrinsics" due to buildbot failures. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134071 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-29Let simplify cfg simplify bb with only debug and lifetime intrinsics.Rafael Espindola
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134057 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-18Fix PR10103: Less code for enum type translation.Hans Wennborg
In cases such as the attached test, where the case value for a switch destination is used in a phi node that follows the destination, it might be better to replace that value with the condition value of the switch, so that more blocks can be folded away with TryToSimplifyUncondBranchFromEmptyBlock because there are less conflicts in the phi node. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133344 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-04If the block that we're threading through is jumped to by an indirect branch,Bill Wendling
then we don't want to set the destination in the indirect branch to the destination. This is because the indirect branch needs its destinations to have had their block addresses taken. This isn't so of the new critical edge that's split during this process. If it turns out that the destination block has only one predecessor, and that being a BB with an indirect branch, then it won't be marked as 'used' and may be removed. PR10072 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132638 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-22Add a parameter to ConstantFoldTerminator() that callers can use to ask it ↵Frits van Bommel
to also clean up the condition of any conditional terminator it folds to be unconditional, if that turns the condition into dead code. This just means it calls RecursivelyDeleteTriviallyDeadInstructions() in strategic spots. It defaults to the old behavior. I also changed -simplifycfg, -jump-threading and -codegenprepare to use this to produce slightly better code without any extra cleanup passes (AFAICT this was the only place in -simplifycfg where now-dead conditions of replaced terminators weren't being cleaned up). The only other user of this function is -sccp, but I didn't read that thoroughly enough to figure out whether it might be holding pointers to instructions that could be deleted by this. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131855 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-19Reapply r131605. This time with a fix, which is to use NoFolder.Devang Patel
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131673 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-19revert 131605 to fix PR9946.Rafael Espindola
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131620 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-19Use IRBuilder.Devang Patel
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131609 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-19Use IRBuilder while simplifying unreachable.Devang Patel
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131607 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-18Use IRBuilder while simplifying conditional branch.Devang Patel
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131605 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-18Use IRBuilder while simplifying branch.Devang Patel
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131598 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-18Use IRBuilder while simplifying return instruction.Devang Patel
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131580 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-18Spread use of IRBuilder even more.Devang Patel
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131571 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-18Use IRBuilder while simplifying switch instruction.Devang Patel
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131566 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-18Use IRBuilder while simplifying unwind.Devang Patel
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131561 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-18Use IRBuilder while simplifying terminator.Devang Patel
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131552 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-18Use IRBuilder while simplifying unconditional branch.Devang Patel
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131551 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-18Use IRBuilder while folding two entry PHINode.Devang Patel
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131548 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-18Set up IRBuilder for use during simplification.Devang Patel
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131545 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-17Preseve line numbers while simplifying CFG.Devang Patel
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131508 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-14SimplifyCFG: Use ComputeMaskedBits to prune dead cases from switch instructions.Benjamin Kramer
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131345 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-29SimplifyCFG: Expose phi node folding cost threshold as command line parameterPeter Collingbourne
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130528 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-29SimplifyCFG: Add CostRemaining parameter to DominatesMergePointPeter Collingbourne
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130527 91177308-0d34-0410-b5e6-96231b3b80d8
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