aboutsummaryrefslogtreecommitdiff
path: root/lib/CodeGen/BranchFolding.cpp
AgeCommit message (Collapse)Author
2010-03-16Remove a check that can no longer be true, after r84803.Bob Wilson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98694 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-14eliminate InvalidateLabel and LabelIDList from MMI and replaceChris Lattner
them with a counter. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98462 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-10Fix another place where DEBUG_VALUE affected codegen.Dale Johannesen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98181 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-10This survived a bootstrap, so let's try 98104 again.Dale Johannesen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98137 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-10Speculatively revert 98104; could be what's causing crashesDale Johannesen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98108 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-09Ever more complicated DEBUG_VALUE fixes for branch folding.Dale Johannesen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98104 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-08Fix dbg value handling in tail merging.Dale Johannesen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97938 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-05Fix some more places where dbg_value affected codegen.Dale Johannesen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97765 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-09move target-independent opcodes out of TargetInstrInfoChris Lattner
into TargetOpcodes.h. #include the new TargetOpcodes.h into MachineInstr. Add new inline accessors (like isPHI()) to MachineInstr, and start using them throughout the codebase. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95687 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-25Rearrange handling of jump tables. Highlights:Chris Lattner
1. MachineJumpTableInfo is now created lazily for a function the first time it actually makes a jump table instead of for every function. 2. The encoding of jump table entries is now described by the MachineJumpTableInfo::JTEntryKind enum. This enum is determined by the TLI::getJumpTableEncoding() hook, instead of by lots of code scattered throughout the compiler that "knows" that jump table entries are always 32-bits in pic mode (for example). 3. The size and alignment of jump table entries is now calculated based on their kind, instead of at machinefunction creation time. Future work includes using the EntryKind in more places in the compiler, eliminating other logic that "knows" the layout of jump tables in various situations. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94470 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-24Change errs() to dbgs().David Greene
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92097 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-16Initialize uninitialized variables.Bill Wendling
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91477 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-16Initialize uninitialized variables.Bill Wendling
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91475 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-15Revert these. They may have been causing 483_xalancbmk to fail:Bill Wendling
$ svn merge -c -91161 https://llvm.org/svn/llvm-project/llvm/trunk --- Reverse-merging r91161 into '.': U lib/CodeGen/BranchFolding.cpp U lib/CodeGen/MachineBasicBlock.cpp $ svn merge -c -91113 https://llvm.org/svn/llvm-project/llvm/trunk --- Reverse-merging r91113 into '.': G lib/CodeGen/MachineBasicBlock.cpp $ svn merge -c -91101 https://llvm.org/svn/llvm-project/llvm/trunk --- Reverse-merging r91101 into '.': U include/llvm/CodeGen/MachineBasicBlock.h G lib/CodeGen/MachineBasicBlock.cpp $ svn merge -c -91092 https://llvm.org/svn/llvm-project/llvm/trunk --- Reverse-merging r91092 into '.': G include/llvm/CodeGen/MachineBasicBlock.h G lib/CodeGen/MachineBasicBlock.cpp git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91376 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-11Don't try to move a MBB into the fall-through position if it's a landing pad orBill Wendling
branches only to a landing pad. Without this check, the compiler would go into an infinite loop because the branch to a landing pad is an "abnormal" edge which wasn't being taken into account. This is the meat of that fix: if (!PrevBB.canFallThrough() && !MBB->BranchesToLandingPad(MBB)) { The other stuff is simplification of the "branches to a landing pad" code. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91161 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-05Remove the target hook TargetInstrInfo::BlockHasNoFallThrough in favor ofDan Gohman
MachineBasicBlock::canFallThrough(), which is target-independent and more thorough. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90634 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-03improve portability to avoid conflicting with std::next in c++'0x.Chris Lattner
Patch by Howard Hinnant! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90365 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-26Split tail duplication into a separate pass. This is needed to avoidBob Wilson
running tail duplication when doing branch folding for if-conversion, and we also want to be able to run tail duplication earlier to fix some reg alloc problems. Move the CanFallThrough function from BranchFolding to MachineBasicBlock so that it can be shared by TailDuplication. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89904 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-24Refactor target hook for tail duplication as requested by Chris.Bob Wilson
Make tail duplication of indirect branches much more aggressive (for targets that indicate that it is profitable), based on further experience with this transformation. I compiled 3 large applications with and without this more aggressive tail duplication and measured minimal changes in code size. ("size" on Darwin seems to round the text size up to the nearest page boundary, so I can only say that any code size increase was less than one 4k page.) Radar 7421267. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89814 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-18There should be no need to keep renumbering blocks during tail duplication.Bob Wilson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89275 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-18Tail duplication still needs to iterate. Duplicating new instructions ontoBob Wilson
the tail of a block may make that block a new candidate for duplication. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89264 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-18Add another statistic to measure code size due to tail duplication.Bob Wilson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89254 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-18Add statistics for tail duplication.Bob Wilson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89225 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-18Add a target hook to allow changing the tail duplication limit based on theBob Wilson
contents of the block to be duplicated. Use this for ARM Cortex A8/9 to be more aggressive tail duplicating indirect branches, since it makes it much more likely that they will be predicted in the branch target buffer. Testcase coming soon. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89187 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-17Remove a special case for tail merging that seems to be both broken andBob Wilson
unnecessary. It is broken because the "isIdenticalTo" check should be negated. If that is fixed, this code causes the CodeGen/X86/tail-opts.ll test to fail, in the dont_merge_oddly function. And, I confirmed that the regression is real -- the generated code is worse. As far as I can tell, that tail-opts.ll test is checking for what this code is supposed to handle and we're doing the right thing anyway. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89121 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-17Set MadeChange instead of MadeChangeThisIteration.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89114 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-17Update a comment, now that tail duplication happens after other branchBob Wilson
folding optimizations. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89109 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-17Perform tail duplication only once, after tail merging is complete.Bob Wilson
It was too difficult to keep the heuristics for merging and duplication consistent. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89105 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-16Fix a comment.Bob Wilson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@88940 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-16Fix some comments.Bob Wilson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@88932 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-16Whitespace: be consistent with pointer syntax.Bob Wilson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@88929 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-16Clean up whitespace.Bob Wilson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@88927 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-13When optimizing for size, don't tail-merge unless it's likely to be aDan Gohman
code-size win, and not when it's only likely to be code-size neutral, such as when only a single instruction would be eliminated and a new branch would be required. This fixes rdar://7392894. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@88692 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-12Make the BranchFolderPass class local to BranchFolding.cpp.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86928 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-12Minor code cleanups.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86926 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-12Tail merge at any size when there are two potentials blocks and oneDan Gohman
can be made to fall through into the other. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86909 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-11Promote MergePotentialsElt and SameTailElt to be regular classesDan Gohman
instead of typedefs for std::pair. This simplifies the type of SameTails, which previously was std::vector<std::pair<std::vector<std::pair<unsigned, MachineBasicBlock *> >::iterator, MachineBasicBlock::iterator> git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86885 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-11Revert this line of 86871.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86875 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-11Add support for tail duplication to BranchFolding, and extendDan Gohman
tail merging support to handle more cases. - Recognize several cases where tail merging is beneficial even when the tail size is smaller than the generic threshold. - Make use of MachineInstrDesc::isBarrier to help detect non-fallthrough blocks. - Check for and avoid disrupting fall-through edges in more cases. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86871 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-11Fix indentation level.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86856 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-11Whitespace cleanups.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86855 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-11Prefix MBB numbers with "BB#" in debug output to make it clear whatDan Gohman
the numbers mean. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86854 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-11Minor code simplification.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86853 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-10Remove an unused variable.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86642 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-10Minor code simplification.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86641 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-03Fix branch folding bug for indirect branches: for a block containing onlyBob Wilson
an unconditional branch (possibly from tail merging), this code is trying to redirect all of its predecessors to go directly to the branch target, but that isn't feasible for indirect branches. The other predecessors (that don't end with indirect branches) could theoretically still be handled, but that is not easily done right now. The AnalyzeBranch interface doesn't currently let us distinguish jump table branches from indirect branches, and this code is currently handling jump tables. To avoid punting on address-taken blocks, we would have to give up handling jump tables. That seems like a bad tradeoff. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85975 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-30Don't delete blocks which have their address taken.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85572 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-29Refactor complicated predicate into a separate function.Bob Wilson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85519 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-28Reimplement BranchFolding change to avoid tail merging for a 1 instructionBob Wilson
common tail, except when the OptimizeForSize function attribute is present. Radar 7338114. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85441 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-28Revert r85346 change to control tail merging by CodeGenOpt::Level.Bob Wilson
I'm going to redo this using the OptimizeForSize function attribute. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85426 91177308-0d34-0410-b5e6-96231b3b80d8