aboutsummaryrefslogtreecommitdiff
path: root/lib/Transforms/Utils/SimplifyCFG.cpp
AgeCommit message (Collapse)Author
2008-07-13Fix mishandling of the infinite loop case when merging two blocks. ThisChris Lattner
fixes PR2540. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53533 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-13more refactoring. Use early exits instead of really complex logic.Chris Lattner
No functionality change. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53532 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-13improve comments.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53531 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-13factor another large hunk of code out into its own function. Chris Lattner
No functionality change. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53530 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-13Final bit of simplification for FoldBranchToCommonDest.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53528 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-13simplify logic a bitChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53527 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-13Refactor some code out into its own helper function, getting rid of crazy ↵Chris Lattner
multiline conditionals and commenting the code better. No functionality change. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53526 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-25- Use O(1) check of basic block size limit.Evan Cheng
- Avoid speculatively execute vector ops. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52703 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-12Do not speculatively execute an instruction by hoisting it to its ↵Evan Cheng
predecessor BB if any of its operands are defined but not used in BB. The transformation will prevent the operand from being sunk into the use block. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52244 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-11For now, avoid generating FP select instructions in order to speculatively ↵Evan Cheng
execute integer arithmetic instructions. FP selects are more likely to be expensive (even compared to branch on fcmp). This is not a wonderful solution but I rather err on the side of conservative. This fixes the heapsort performance regressions. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52224 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-10op_iterator-ify loopsGabor Greif
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52191 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-07Speculatively execute a block when the the block is the then part of a ↵Evan Cheng
triangle shape and it contains a single, side effect free, cheap instruction. The branch is eliminated by adding a select instruction. i.e. Turn BB: %t1 = icmp br i1 %t1, label %BB1, label %BB2 BB1: %t3 = add %t2, c br label BB2 BB2: => BB: %t1 = icmp %t4 = add %t2, c %t3 = select i1 %t1, %t2, %t3 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52073 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-23Tidy up BasicBlock::getFirstNonPHI, and change a bunch of places toDan Gohman
use it instead of duplicating its functionality. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51499 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-23Restucture a part of the SimplifyCFG pass and include a testcase.Matthijs Kooijman
The SimplifyCFG pass looks at basic blocks that contain only phi nodes, followed by an unconditional branch. In a lot of cases, such a block (BB) can be merged into their successor (Succ). This merging is performed by TryToSimplifyUncondBranchFromEmptyBlock. It does this by taking all phi nodes in the succesor block Succ and expanding them to include the predecessors of BB. Furthermore, any phi nodes in BB are moved to Succ and expanded to include the predecessors of Succ as well. Before attempting this merge, CanPropagatePredecessorsForPHIs checks to see if all phi nodes can be properly merged. All functional changes are made to this function, only comments were updated in TryToSimplifyUncondBranchFromEmptyBlock. In the original code, CanPropagatePredecessorsForPHIs looks quite convoluted and more like stack of checks added to handle different kinds of situations than a comprehensive check. In particular the first check in the function did some value checking for the case that BB and Succ have a common predecessor, while the last check in the function simply rejected all cases where BB and Succ have a common predecessor. The first check was still useful in the case that BB did not contain any phi nodes at all, though, so it was not completely useless. Now, CanPropagatePredecessorsForPHIs is restructured to to look a lot more similar to the code that actually performs the merge. Both functions now look at the same phi nodes in about the same order. Any conflicts (phi nodes with different values for the same source) that could arise from merging or moving phi nodes are detected. If no conflicts are found, the merge can happen. Apart from only restructuring the checks, two main changes in functionality happened. Firstly, the old code rejected blocks with common predecessors in most cases. The new code performs some extra checks so common predecessors can be handled in a lot of cases. Wherever common predecessors still pose problems, the blocks are left untouched. Secondly, the old code rejected the merge when values (phi nodes) from BB were used in any other place than Succ. However, it does not seem that there is any situation that would require this check. Even more, this can be proven. Consider that BB is a block containing of a single phi node "%a" and a branch to Succ. Now, since the definition of %a will dominate all of its uses, BB will dominate all blocks that use %a. Furthermore, since the branch from BB to Succ is unconditional, Succ will also dominate all uses of %a. Now, assume that one predecessor of Succ is not dominated by BB (and thus not dominated by Succ). Since at least one use of %a (but in reality all of them) is reachable from Succ, you could end up at a use of %a without passing through it's definition in BB (by coming from X through Succ). This is a contradiction, meaning that our original assumption is wrong. Thus, all predecessors of Succ must also be dominated by BB (and thus also by Succ). This means that moving the phi node %a from BB to Succ does not pose any problems when the two blocks are merged, and any use checks are not needed. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51478 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-16API change for {BinaryOperator|CmpInst|CastInst}::create*() --> Create. ↵Gabor Greif
Legacy interfaces will be in place for some time. (Merge from use-diet branch.) git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51200 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-15Fix a bunch of 80col violations that arose from the Create API change. Tweak ↵Gabor Greif
makefile targets to find these better. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51143 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-28Fix PR2256, yet another miscompilation in simplifycfg of iChris Lattner
multiple return values. Bill, please pull this into Tak. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50332 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-25Remove 'unwinds to' support from mainline. This patch undoes r47802 r47989Nick Lewycky
r48047 r48084 r48085 r48086 r48088 r48096 r48099 r48109 and r48123. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50265 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-24Split some code out of the main SimplifyCFG loop into its own function.Chris Lattner
Fix said code to handle merging return instructions together correctly when handling multiple return values. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50199 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-06API changes for class Use size reduction, wave 1.Gabor Greif
Specifically, introduction of XXX::Create methods for Users that have a potentially variable number of Uses. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49277 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-11Check to see if a two-entry PHI block can be simplifiedDan Gohman
before trying to merge the block into its predecessors. This allows two-entry-phi-return.ll to be simplified into a single basic block. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48252 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-10Turn unwind_to into "unwinds to".Nick Lewycky
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48123 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-09Firstly, having a BranchInst isn't exclusive with having an unwind_to.Nick Lewycky
Secondly, we have to check whether the branch is actually pointing to the block with the unwind in it. We could have gotten here because of the unwind_to alone. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48099 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-09A BB that unwind_to an "unwind" inst is that same as one that doesn't unwind_toNick Lewycky
at all. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48096 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-09Update the inliner and simplifycfg to handle unwind_to.Nick Lewycky
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48086 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-20Make Transforms to be 4.3 warnings-cleanAnton Korobeynikov
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47371 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-18switch simplifycfg from using vectors for most things to smallvectors,Chris Lattner
this speeds it up 2.3% on eon. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47261 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-03don't hoist FP additions into unconditional adds + selects. This Chris Lattner
could theoretically introduce a trap, but is also a performance issue. This speeds up ptrdist/ks by 8%. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45533 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-29Remove attribution from file headers, per discussion on llvmdev.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45418 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-22If succ has succ itself as one of the predecessors then doDevang Patel
not merge current bb and succ even if bb's terminator is unconditional branch to succ. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45305 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-27Fix PR1146: parameter attributes are longer part ofDuncan Sands
the function type, instead they belong to functions and function calls. This is an updated and slightly corrected version of Reid Spencer's original patch. The only known problem is that auto-upgrading of bitcode files doesn't seem to work properly (see test/Bitcode/AutoUpgradeIntrinsics.ll). Hopefully a bitcode guru (who might that be? :) ) will fix it. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44359 91177308-0d34-0410-b5e6-96231b3b80d8
2007-08-01New CallInst interface to address GLIBCXX_DEBUG errors caused byDavid Greene
indexing an empty std::vector. Updates to all clients. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40660 91177308-0d34-0410-b5e6-96231b3b80d8
2007-05-24Minor comment cleanups.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37321 91177308-0d34-0410-b5e6-96231b3b80d8
2007-04-17remove use of Instruction::getNextChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36199 91177308-0d34-0410-b5e6-96231b3b80d8
2007-04-02reduce use of std::setChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35576 91177308-0d34-0410-b5e6-96231b3b80d8
2007-03-22Change uses of Function::front to Function::getEntryBlock for readability.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35265 91177308-0d34-0410-b5e6-96231b3b80d8
2007-03-02Make sorting of ConstantInt be APInt clean through use of ult function.Reid Spencer
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34853 91177308-0d34-0410-b5e6-96231b3b80d8
2007-02-13Eliminate use of ctors that take vectors.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34219 91177308-0d34-0410-b5e6-96231b3b80d8
2007-02-11simplify code by using Value::takeNameChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34177 91177308-0d34-0410-b5e6-96231b3b80d8
2007-01-30Adjust #includes to match movement of constant folding code from ↵Chris Lattner
transformutils to libanalysis. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@33680 91177308-0d34-0410-b5e6-96231b3b80d8
2007-01-19For PR1043:Reid Spencer
This is the final patch for this PR. It implements some minor cleanup in the use of IntegerType, to wit: 1. Type::getIntegerTypeMask -> IntegerType::getBitMask 2. Type::Int*Ty changed to IntegerType* from Type* 3. ConstantInt::getType() returns IntegerType* now, not Type* This also fixes PR1120. Patch by Sheng Zhou. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@33370 91177308-0d34-0410-b5e6-96231b3b80d8
2007-01-15rename Type::isIntegral to Type::isInteger, eliminating the old Type::isInteger.Chris Lattner
rename Type::getIntegralTypeMask to Type::getIntegerTypeMask. This makes naming much more consistent. For example, there are now no longer any instances of IntegerType that are not considered isInteger! :) git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@33225 91177308-0d34-0410-b5e6-96231b3b80d8
2007-01-15Eliminate calls to isInteger, generalizing code and tightening checks as needed.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@33218 91177308-0d34-0410-b5e6-96231b3b80d8
2007-01-12Implement review feedback for the ConstantBool->ConstantInt merge. ChrisReid Spencer
recommended that getBoolValue be replaced with getZExtValue and that get(bool) be replaced by get(const Type*, uint64_t). This implements those changes. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@33110 91177308-0d34-0410-b5e6-96231b3b80d8
2007-01-11Rename BoolTy as Int1Ty. Patch by Sheng Zhou.Reid Spencer
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@33076 91177308-0d34-0410-b5e6-96231b3b80d8
2007-01-11For PR1043:Zhou Sheng
Merge ConstantIntegral and ConstantBool into ConstantInt. Remove ConstantIntegral and ConstantBool from LLVM. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@33073 91177308-0d34-0410-b5e6-96231b3b80d8
2006-12-23For PR950:Reid Spencer
This patch removes the SetCC instructions and replaces them with the ICmp and FCmp instructions. The SetCondInst instruction has been removed and been replaced with ICmpInst and FCmpInst. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@32751 91177308-0d34-0410-b5e6-96231b3b80d8
2006-11-27For PR950:Reid Spencer
The long awaited CAST patch. This introduces 12 new instructions into LLVM to replace the cast instruction. Corresponding changes throughout LLVM are provided. This passes llvm-test, llvm/test, and SPEC CPUINT2000 with the exception of 175.vpr which fails only on a slight floating point output difference. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31931 91177308-0d34-0410-b5e6-96231b3b80d8
2006-11-26Remove #include <iostream> and use llvm_* streams instead.Bill Wendling
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31925 91177308-0d34-0410-b5e6-96231b3b80d8
2006-11-18Do not convert massive blocks on phi nodes into select statements. InsteadChris Lattner
only do these transformations if there are a small number of phi's. This speeds up Ptrdist/ks from 2.35s to 2.19s on my mac pro. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31853 91177308-0d34-0410-b5e6-96231b3b80d8