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path: root/lib/Transforms/Scalar/JumpThreading.cpp
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2011-06-27Calculate GetBestDestForJumpOnUndef correctly.Jakub Staszak
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133946 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
2011-05-04Preserve line number information while threading jumps.Devang Patel
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130880 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-14Fix an infinite alternation in JumpThreading where two transforms would ↵Owen Anderson
repeatedly undo each other. The solution is to perform more aggressive constant folding to make one of the edges just folded away rather than trying to thread it. Fixes <rdar://problem/9284786>. Discovered with CSmith. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129538 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-30Remove PHINode::reserveOperandSpace(). Instead, add a parameter toJay Foad
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
2011-03-30(Almost) always call reserveOperandSpace() on newly created PHINodes.Jay Foad
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128535 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-18prevent jump threading from merging blocks when their address isChris Lattner
taken (and used!). This prevents merging the blocks (invalidating the block addresses) in a case like this: #define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; }) void foo() { printf("%p\n", _THIS_IP_); printf("%p\n", _THIS_IP_); printf("%p\n", _THIS_IP_); } which fixes PR4151. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125829 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-16Fix a bug in the loop in JumpThreading::ProcessThreadableEdges() where it ↵Frits van Bommel
could falsely produce a MultipleDestSentinel value if the first predecessor ended with an 'indirectbr'. If that happened, it caused an unnecessary FindMostPopularDest() call. This wasn't a correctness problem, but it broke the fast path for single-predecessor blocks. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121966 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-15Teach jump threading to "look through" a select when the branch direction of ↵Frits van Bommel
a terminator depends on it. When it sees a promising select it now tries to figure out whether the condition of the select is known in any of the predecessors and if so it maps the operands appropriately. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121859 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13simplify code and reduce indentationChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121670 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-07Remove some dead code from the jump threading pass.Frits van Bommel
The last uses of these functions were removed in r113852 when LazyValueInfo was permanently enabled and removed the need for them. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121133 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-06Implement jump threading of 'indirectbr' by keeping track of whether we're ↵Frits van Bommel
looking for ConstantInt*s or BlockAddress*s. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121066 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-05Refactor jump threading.Frits van Bommel
Should have no functional change other than the order of two transformations that are mutually-exclusive and the exact formatting of debug output. Internally, it now stores the ConstantInt*s as Constant*s, and actual undef values instead of nulls. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120946 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-05Remove trailing whitespace.Frits van Bommel
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120945 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-19Get rid of static constructors for pass registration. Instead, every pass ↵Owen Anderson
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
2010-10-12Begin adding static dependence information to passes, which will allow us toOwen Anderson
perform initialization without static constructors AND without explicit initialization by the client. For the moment, passes are required to initialize both their (potential) dependencies and any passes they preserve. I hope to be able to relax the latter requirement in the future. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116334 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-07Now with fewer extraneous semicolons!Owen Anderson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115996 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-29Fix PR8247: JumpThreading can cause a block to become unreachable while ↵Owen Anderson
still having predecessor, if it is part of a self-loop. Because of this, we cannot use the Simplify* APIs, as they can assert-fail on unreachable code. Since it's not easy to determine if a given threading will cause a block to become unreachable, simply defer simplifying simplification to later InstCombine and/or DCE passes. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115082 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-14Remove the option to disable LazyValueInfo in JumpThreading, as it is nowOwen Anderson
on by default and has received significant testing. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113852 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-05Change lower atomic pass to use IntrinsicInst to simplify it a bit.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113114 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-05eliminate some non-obvious casts. UndefValue isa Constant.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113113 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-02Reapply commit 112699, speculatively reverted by echristo, sinceDuncan Sands
I'm sure it is harmless. Original commit message: If PrototypeValue is erased in the middle of using the SSAUpdator then the SSAUpdator may access freed memory. Instead, simply pass in the type and name explicitly, which is all that was used anyway. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112810 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-01JumpThreading keeps LazyValueInfo up to date, so we don't need to rerun itOwen Anderson
if we schedule another LVI-using pass afterwards. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112722 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-01Speculatively revert 112699 and 112702, they seem to be causingEric Christopher
self host errors on clang-x86-64. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112719 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-01If PrototypeValue is erased in the middle of using the SSAUpdatorDuncan Sands
then the SSAUpdator may access freed memory. Instead, simply pass in the type and name explicitly, which is all that was used anyway. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112699 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-31More cleanups of my JumpThreading transforms, including extracting some ↵Owen Anderson
duplicated code into a helper function. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112634 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-31Add an RAII helper to make cleanup of the RecursionSet more fool-proof.Owen Anderson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112628 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-31Refactor my fix for PR5652 to terminate the predecessor lookups after the ↵Owen Anderson
first failure. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112620 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-31More Chris-inspired JumpThreading fixes: use ConstantExpr to correctly ↵Owen Anderson
constant-fold undef, and be more careful with its return value. This actually exposed an infinite recursion bug in ComputeValueKnownInPredecessors which theoretically already existed (in JumpThreading's handling of and/or of i1's), but never manifested before. This patch adds a tracking set to prevent this case. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112589 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-30Re-apply r112539, being more careful to respect the return values of the ↵Owen Anderson
constant folding methods. Additionally, use the ConstantExpr::get*() methods to simplify some constant folding. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112550 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-30Revert r112539. It accidentally introduced a miscompilation.Owen Anderson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112543 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-30Fixes and cleanups pointed out by Chris. In general, be careful to handle 0 ↵Owen Anderson
results from ComputeValueKnownInPredecessors (indicating undef), and re-use existing constant folding APIs. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112539 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-27Fix typos in comments.Owen Anderson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112286 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-27Use LVI to eliminate conditional branches where we've tested a related ↵Owen Anderson
condition previously. Update tests for this change. This fixes PR5652. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112270 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-26Make JumpThreading smart enough to properly thread StrSwitch when it's ↵Owen Anderson
compiled with clang++. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112198 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-24Turn LVI on, previously detected failures should be fixed now.Owen Anderson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111923 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-23Turn LVI back off, I have a testcase now.Owen Anderson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111834 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-23Re-enable LazyValueInfo. Monitoring for failures.Owen Anderson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111816 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-19Disable LVI while I evaluate a failure.Owen Anderson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111551 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-19Tentatively enabled LVI by default. I'll be monitoring for any failures.Owen Anderson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111543 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-18Inform LazyValueInfo whenever a block is deleted, to avoid dangling pointer ↵Owen Anderson
issues. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111382 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-18Fix PR7755: knowing something about an inval for a predChris Lattner
from the LHS should disable reconsidering that pred on the RHS. However, knowing something about the pred on the RHS shouldn't disable subsequent additions on the RHS from happening. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111349 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-06Reapply r110396, with fixes to appease the Linux buildbot gods.Owen Anderson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110460 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-06Revert r110396 to fix buildbots.Owen Anderson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110410 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-05Don't use PassInfo* as a type identifier for passes. Instead, use the ↵Owen Anderson
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
2010-08-05Give JumpThreading+LVI a long-form cl::opt so that it's easier to toggle the ↵Owen Anderson
default. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110384 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-26Add an initial implementation of LazyValueInfo updating for JumpThreading. ↵Owen Anderson
Disabled for now. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@109424 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-21Fix batch of converting RegisterPass<> to INTIALIZE_PASS().Owen Anderson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@109045 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-12cache results of operator*Gabor Greif
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108142 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-12if jump threading is able to infer interesting values on bothChris Lattner
the LHS and RHS of an and/or instruction, don't multiply add known predecessor values. This fixes the crash on testcase from PR7498 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108114 91177308-0d34-0410-b5e6-96231b3b80d8
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