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path: root/lib/Transforms/Scalar/TailRecursionElimination.cpp
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* TRE: Move class into anonymous namespace.Benjamin Kramer2013-07-24
| | | | | | While there shrink a dangerously large SmallPtrSet. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187050 91177308-0d34-0410-b5e6-96231b3b80d8
* Use SmallVectorImpl& instead of SmallVector to avoid repeating small vector ↵Craig Topper2013-07-14
| | | | | | size. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186274 91177308-0d34-0410-b5e6-96231b3b80d8
* Teach TailRecursionElimination to handle certain cases of nocapture escaping ↵Michael Gottesman2013-07-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | allocas. Without the changes introduced into this patch, if TRE saw any allocas at all, TRE would not perform TRE *or* mark callsites with the tail marker. Because TRE runs after mem2reg, this inadequacy is not a death sentence. But given a callsite A without escaping alloca argument, A may not be able to have the tail marker placed on it due to a separate callsite B having a write-back parameter passed in via an argument with the nocapture attribute. Assume that B is the only other callsite besides A and B only has nocapture escaping alloca arguments (*NOTE* B may have other arguments that are not passed allocas). In this case not marking A with the tail marker is unnecessarily conservative since: 1. By assumption A has no escaping alloca arguments itself so it can not access the caller's stack via its arguments. 2. Since all of B's escaping alloca arguments are passed as parameters with the nocapture attribute, we know that B does not stash said escaping allocas in a manner that outlives B itself and thus could be accessed indirectly by A. With the changes introduced by this patch: 1. If we see any escaping allocas passed as a capturing argument, we do nothing and bail early. 2. If we do not see any escaping allocas passed as captured arguments but we do see escaping allocas passed as nocapture arguments: i. We do not perform TRE to avoid PR962 since the code generator produces significantly worse code for the dynamic allocas that would be created by the TRE algorithm. ii. If we do not return twice, mark call sites without escaping allocas with the tail marker. *NOTE* This excludes functions with escaping nocapture allocas. 3. If we do not see any escaping allocas at all (whether captured or not): i. If we do not have usage of setjmp, mark all callsites with the tail marker. ii. If there are no dynamic/variable sized allocas in the function, attempt to perform TRE on all callsites in the function. Based off of a patch by Nick Lewycky. rdar://14324281. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186057 91177308-0d34-0410-b5e6-96231b3b80d8
* Begin fleshing out an interface in TTI for modelling the costs ofChandler Carruth2013-01-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | generic function calls and intrinsics. This is somewhat overlapping with an existing intrinsic cost method, but that one seems targetted at vector intrinsics. I'll merge them or separate their names and use cases in a separate commit. This sinks the test of 'callIsSmall' down into TTI where targets can control it. The whole thing feels very hack-ish to me though. I've left a FIXME comment about the fundamental design problem this presents. It isn't yet clear to me what the users of this function *really* care about. I'll have to do more analysis to figure that out. Putting this here at least provides it access to proper analysis pass tools and other such. It also allows us to more cleanly implement the baseline cost interfaces in TTI. With this commit, it is now theoretically possible to simplify much of the inline cost analysis's handling of calls by calling through to this interface. That conversion will have to happen in subsequent commits as it requires more extensive restructuring of the inline cost analysis. The CodeMetrics class is now really only in the business of running over a block of code and aggregating the metrics on that block of code, with the actual cost evaluation done entirely in terms of TTI. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173148 91177308-0d34-0410-b5e6-96231b3b80d8
* Move all of the header files which are involved in modelling the LLVM IRChandler Carruth2013-01-02
| | | | | | | | | | | | | | | | | | | | | into their new header subdirectory: include/llvm/IR. This matches the directory structure of lib, and begins to correct a long standing point of file layout clutter in LLVM. There are still more header files to move here, but I wanted to handle them in separate commits to make tracking what files make sense at each layer easier. The only really questionable files here are the target intrinsic tablegen files. But that's a battle I'd rather not fight today. I've updated both CMake and Makefile build systems (I think, and my tests think, but I may have missed something). I've also re-sorted the includes throughout the project. I'll be committing updates to Clang, DragonEgg, and Polly momentarily. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171366 91177308-0d34-0410-b5e6-96231b3b80d8
* Use the new script to sort the includes of every file under lib.Chandler Carruth2012-12-03
| | | | | | | | | | | | | | | | | Sooooo many of these had incorrect or strange main module includes. I have manually inspected all of these, and fixed the main module include to be the nearest plausible thing I could find. If you own or care about any of these source files, I encourage you to take some time and check that these edits were sensible. I can't have broken anything (I strictly added headers, and reordered them, never removed), but they may not be the headers you'd really like to identify as containing the API being implemented. Many forward declarations and missing includes were added to a header files to allow them to parse cleanly when included first. The main module rule does in fact have its merits. =] git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169131 91177308-0d34-0410-b5e6-96231b3b80d8
* Revert r166407 because it caused analyzer tests to crash and broke self-host ↵Argyrios Kyrtzidis2012-10-22
| | | | | | bots. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166424 91177308-0d34-0410-b5e6-96231b3b80d8
* Reapply r166405, teaching tailcallelim to be smarter about nocapture, with aNick Lewycky2012-10-22
| | | | | | | | | | | | | | | | | very small but very important bugfix: bool shouldExplore(Use *U) { Value *V = U->get(); if (isa<CallInst>(V) || isa<InvokeInst>(V)) [...] should have read: bool shouldExplore(Use *U) { Value *V = U->getUser(); if (isa<CallInst>(V) || isa<InvokeInst>(V)) Fixes PR14143! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166407 91177308-0d34-0410-b5e6-96231b3b80d8
* Revert r166405, "Teach TailRecursionElimination to consider 'nocapture' when ↵NAKAMURA Takumi2012-10-22
| | | | | | | | deciding whether" It broke selfhosting stage2 in several builders. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166406 91177308-0d34-0410-b5e6-96231b3b80d8
* Teach TailRecursionElimination to consider 'nocapture' when deciding whetherNick Lewycky2012-10-21
| | | | | | | calls can be marked tail. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166405 91177308-0d34-0410-b5e6-96231b3b80d8
* Clean whitespaces.Nadav Rotem2012-07-24
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160668 91177308-0d34-0410-b5e6-96231b3b80d8
* A pile of long over-due refactorings here. There are some very, *very*Chandler Carruth2012-05-04
| | | | | | | | | | | | | | | | | | | | | | | | | | minor behavior changes with this, but nothing I have seen evidence of in the wild or expect to be meaningful. The real goal is unifying our logic and simplifying the interfaces. A summary of the changes follows: - Make 'callIsSmall' actually accept a callsite so it can handle intrinsics, and simplify callers appropriately. - Nuke a completely bogus declaration of 'callIsSmall' that was still lurking in InlineCost.h... No idea how this got missed. - Teach the 'isInstructionFree' about the various more intelligent 'free' heuristics that got added to the inline cost analysis during review and testing. This mostly surrounds int->ptr and ptr->int casts. - Switch most of the interesting parts of the inline cost analysis that were essentially computing 'is this instruction free?' to use the code metrics routine instead. This way we won't keep duplicating logic. All of this is motivated by the desire to allow other passes to compute a roughly equivalent 'cost' metric for a particular basic block as the inline cost analysis. Sadly, re-using the same analysis for both is really messy because only the actual inline cost analysis is ever going to go to the contortions required for simplification, SROA analysis, etc. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156140 91177308-0d34-0410-b5e6-96231b3b80d8
* Correct over-zealous removal of hack.Bill Wendling2011-10-17
| | | | | | | | Some code want to check that *any* call within a function has the 'returns twice' attribute, not just that the current function has one. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142221 91177308-0d34-0410-b5e6-96231b3b80d8
* Now that we have the ReturnsTwice function attribute, this method isBill Wendling2011-10-17
| | | | | | | | obsolete. Check the attribute instead. <rdar://problem/8031714> git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142212 91177308-0d34-0410-b5e6-96231b3b80d8
* Don't do tail calls in a function that call setjmp. The stack might beRafael Espindola2011-05-16
| | | | | | corrupted when setjmp returns again. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131399 91177308-0d34-0410-b5e6-96231b3b80d8
* Do not lose line number info while eliminating tail call.Devang Patel2011-04-28
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130419 91177308-0d34-0410-b5e6-96231b3b80d8
* Fix a ton of comment typos found by codespell. Patch byChris Lattner2011-04-15
| | | | | | | | Luis Felipe Strano Moraes! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129558 91177308-0d34-0410-b5e6-96231b3b80d8
* Remove PHINode::reserveOperandSpace(). Instead, add a parameter toJay Foad2011-03-30
| | | | | | PHINode::Create() giving the (known or expected) number of operands. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128537 91177308-0d34-0410-b5e6-96231b3b80d8
* (Almost) always call reserveOperandSpace() on newly created PHINodes.Jay Foad2011-03-30
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128535 91177308-0d34-0410-b5e6-96231b3b80d8
* Unbreak the MSVC build.Francois Pichet2011-01-29
| | | | | | The DEBUG() call at line 606 demands to see raw_ostream's definition. I have no idea why this seems to only break MSVC. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124545 91177308-0d34-0410-b5e6-96231b3b80d8
* Add a test for TCE return duplication.Evan Cheng2011-01-29
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124527 91177308-0d34-0410-b5e6-96231b3b80d8
* Re-apply r124518 with fix. Watch out for invalidated iterator.Evan Cheng2011-01-29
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124526 91177308-0d34-0410-b5e6-96231b3b80d8
* Revert r124518. It broke Linux self-host.Evan Cheng2011-01-29
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124522 91177308-0d34-0410-b5e6-96231b3b80d8
* Re-commit r124462 with fixes. Tail recursion elim will now dup ret into ↵Evan Cheng2011-01-29
| | | | | | unconditional predecessor to enable TCE on demand. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124518 91177308-0d34-0410-b5e6-96231b3b80d8
* Have a few places that want to simplify phi nodes use SimplifyInstructionDuncan Sands2010-11-16
| | | | | | | rather than calling hasConstantValue. No intended functionality change. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119352 91177308-0d34-0410-b5e6-96231b3b80d8
* Get rid of static constructors for pass registration. Instead, every pass ↵Owen Anderson2010-10-19
| | | | | | | | | | | | | | | | | | exposes an initializeMyPassFunction(), which must be called in the pass's constructor. This function uses static dependency declarations to recursively initialize the pass's dependencies. Clients that only create passes through the createFooPass() APIs will require no changes. Clients that want to use the CommandLine options for passes will need to manually call the appropriate initialization functions in PassInitialization.h before parsing commandline arguments. I have tested this with all standard configurations of clang and llvm-gcc on Darwin. It is possible that there are problems with the static dependencies that will only be visible with non-standard options. If you encounter any crash in pass registration/creation, please send the testcase to me directly. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116820 91177308-0d34-0410-b5e6-96231b3b80d8
* Now with fewer extraneous semicolons!Owen Anderson2010-10-07
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115996 91177308-0d34-0410-b5e6-96231b3b80d8
* tidy upChris Lattner2010-08-31
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112643 91177308-0d34-0410-b5e6-96231b3b80d8
* Reapply r110396, with fixes to appease the Linux buildbot gods.Owen Anderson2010-08-06
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110460 91177308-0d34-0410-b5e6-96231b3b80d8
* Revert r110396 to fix buildbots.Owen Anderson2010-08-06
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110410 91177308-0d34-0410-b5e6-96231b3b80d8
* Don't use PassInfo* as a type identifier for passes. Instead, use the ↵Owen Anderson2010-08-05
| | | | | | | | | address of the static ID member as the sole unique type identifier. Clean up APIs related to this change. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110396 91177308-0d34-0410-b5e6-96231b3b80d8
* Fix batch of converting RegisterPass<> to INTIALIZE_PASS().Owen Anderson2010-07-21
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@109045 91177308-0d34-0410-b5e6-96231b3b80d8
* Handle the case of a tail recursion in which the tail call is followedDuncan Sands2010-07-13
| | | | | | | | | | by a return that returns a constant, while elsewhere in the function another return instruction returns a different constant. This is a special case of accumulator recursion, so just generalize the existing logic a bit. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108241 91177308-0d34-0410-b5e6-96231b3b80d8
* cache dereferenced iteratorsGabor Greif2010-07-12
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108131 91177308-0d34-0410-b5e6-96231b3b80d8
* The accumulator tail recursion transform claims to work for any associativeDuncan Sands2010-07-10
| | | | | | | | | | | | | | | | | operation, but the way it's implemented requires the operation to also be commutative. So add a check for commutativity (and tweak the corresponding comments). This makes no difference in practice since every associative LLVM instruction is also commutative! Here's an example to show the need for commutativity: the accum_recursion.ll testcase calculates the factorial function. Before the transformation the result of a call is ((((1*1)*2)*3)...)*x while afterwards it is (((1*x)*(x-1))...*2)*1 which clearly requires both associativity and commutativity of * to be equal to the original. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108056 91177308-0d34-0410-b5e6-96231b3b80d8
* Fix PR7328: when turning a tail recursion into a loop, need to preserveDuncan Sands2010-06-26
| | | | | | | | | the returned value after the tail call if it differs from other return values. The optimal thing to do would be to introduce a phi node for the return value, but for the moment just fix the miscompile. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106947 91177308-0d34-0410-b5e6-96231b3b80d8
* use getNumArgOperandsGabor Greif2010-06-24
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106709 91177308-0d34-0410-b5e6-96231b3b80d8
* use ArgOperand APIGabor Greif2010-06-24
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106707 91177308-0d34-0410-b5e6-96231b3b80d8
* Move FindAvailableLoadedValue isSafeToLoadUnconditionally out ofDan Gohman2010-05-28
| | | | | | | | lib/Transforms/Utils and into lib/Analysis so that Analysis passes can use them. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104949 91177308-0d34-0410-b5e6-96231b3b80d8
* Revert 101465, it broke internal OpenGL testing.Eric Christopher2010-04-16
| | | | | | | | Probably the best way to know that all getOperand() calls have been handled is to replace that API instead of updating. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101579 91177308-0d34-0410-b5e6-96231b3b80d8
* Refine the detection of seemingly infinitely recursive calls where theDan Gohman2010-04-16
| | | | | | | | callee is expected to be expanded to something else by codegen, so that normal infinitely recursive calls are still transformed. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101468 91177308-0d34-0410-b5e6-96231b3b80d8
* reapply r101434Gabor Greif2010-04-16
| | | | | | | | | | | | | | with a fix for self-hosting rotate CallInst operands, i.e. move callee to the back of the operand array the motivation for this patch are laid out in my mail to llvm-commits: more efficient access to operands and callee, faster callgraph-construction, smaller compiler binary git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101465 91177308-0d34-0410-b5e6-96231b3b80d8
* back out r101423 and r101397, they break llvm-gcc self-host on darwin10Gabor Greif2010-04-16
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101434 91177308-0d34-0410-b5e6-96231b3b80d8
* reapply r101364, which has been backed out in r101368Gabor Greif2010-04-15
| | | | | | | | | | | | | | with a fix rotate CallInst operands, i.e. move callee to the back of the operand array the motivation for this patch are laid out in my mail to llvm-commits: more efficient access to operands and callee, faster callgraph-construction, smaller compiler binary git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101397 91177308-0d34-0410-b5e6-96231b3b80d8
* back out r101364, as it trips the linux nightlybot on some clang C++ testsGabor Greif2010-04-15
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101368 91177308-0d34-0410-b5e6-96231b3b80d8
* rotate CallInst operands, i.e. move callee to the backGabor Greif2010-04-15
| | | | | | | | | | | of the operand array the motivation for this patch are laid out in my mail to llvm-commits: more efficient access to operands and callee, faster callgraph-construction, smaller compiler binary git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101364 91177308-0d34-0410-b5e6-96231b3b80d8
* Revert 94937 and move the noreturn check to codegen.Evan Cheng2010-02-03
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95198 91177308-0d34-0410-b5e6-96231b3b80d8
* Do not mark no-return calls tail calls. It'll screw up special calls like ↵Evan Cheng2010-01-31
| | | | | | longjmp and it doesn't make much sense for performance reason. If my logic is faulty, please let me know. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94937 91177308-0d34-0410-b5e6-96231b3b80d8
* Check alignment of loads when deciding whether it is safe to execute themBob Wilson2010-01-30
| | | | | | | | unconditionally. Besides checking the offset, also check that the underlying object is aligned as much as the load itself. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94875 91177308-0d34-0410-b5e6-96231b3b80d8
* Improve tail call elimination to handle the switch statement.Nick Lewycky2009-11-07
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86403 91177308-0d34-0410-b5e6-96231b3b80d8
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