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2011-11-14Reuse the logic in getEdgeProbability within getHotSucc in order toChandler Carruth
correctly handle blocks whose successor weights sum to more than UINT32_MAX. This is slightly less efficient, but the entire thing is already linear on the number of successors. Calling it within any hot routine is a mistake, and indeed no one is calling it. It also simplifies the code. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144527 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-14Fix an overflow bug in MachineBranchProbabilityInfo. This pass relied onChandler Carruth
the sum of the edge weights not overflowing uint32, and crashed when they did. This is generally safe as BranchProbabilityInfo tries to provide this guarantee. However, the CFG can get modified during codegen in a way that grows the *sum* of the edge weights. This doesn't seem unreasonable (imagine just adding more blocks all with the default weight of 16), but it is hard to come up with a case that actually triggers 32-bit overflow. Fortuately, the single-source GCC build is good at this. The solution isn't very pretty, but its no worse than the previous code. We're already summing all of the edge weights on each query, we can sum them, check for an overflow, compute a scale, and sum them again. I've included a *greatly* reduced test case out of the GCC source that triggers it. It's a pretty lame test, as it clearly is just barely triggering the overflow. I'd like to have something that is much more definitive, but I don't understand the fundamental pattern that triggers an explosion in the edge weight sums. The buggy code is duplicated within this file. I'll colapse them into a single implementation in a subsequent commit. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144526 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-14Use getVNInfoBefore() when it makes sense.Jakob Stoklund Olesen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144517 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-14Teach machine block placement to cope with unnatural loops. These don'tChandler Carruth
get loop info structures associated with them, and so we need some way to make forward progress selecting and placing basic blocks. The technique used here is pretty brutal -- it just scans the list of blocks looking for the first unplaced candidate. It keeps placing blocks like this until the CFG becomes tractable. The cost is somewhat unfortunate, it requires allocating a vector of all basic block pointers eagerly. I have some ideas about how to simplify and optimize this, but I'm trying to get the logic correct first. Thanks to Benjamin Kramer for the reduced test case out of GCC. Sadly there are other bugs that GCC is tickling that I'm reducing and working on now. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144516 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-13Use kill slots instead of the previous slot in shrinkToUses.Jakob Stoklund Olesen
It's more natural to use the actual end points. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144515 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-13Cleanup some 80-columns violations and poor formatting. These snuck byChandler Carruth
when I was reading through the code for style. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144513 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-13Terminate all dead defs at the dead slot instead of the 'next' slot.Jakob Stoklund Olesen
This makes no difference for normal defs, but early clobber dead defs now look like: [Slot_EarlyClobber; Slot_Dead) instead of: [Slot_EarlyClobber; Slot_Register). Live ranges for normal dead defs look like: [Slot_Register; Slot_Dead) as before. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144512 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-13Simplify early clobber slots a bit.Jakob Stoklund Olesen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144507 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-13Enhance the assertion mechanisms in place to make it easier to catchChandler Carruth
when we fail to place all the blocks of a loop. Currently this is happening for unnatural loops, and this logic helps more immediately point to the problem. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144504 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-13Rename SlotIndexes to match how they are used.Jakob Stoklund Olesen
The old naming scheme (load/use/def/store) can be traced back to an old linear scan article, but the names don't match how slots are actually used. The load and store slots are not needed after the deferred spill code insertion framework was deleted. The use and def slots don't make any sense because we are using half-open intervals as is customary in C code, but the names suggest closed intervals. In reality, these slots were used to distinguish early-clobber defs from normal defs. The new naming scheme also has 4 slots, but the names match how the slots are really used. This is a purely mechanical renaming, but some of the code makes a lot more sense now. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144503 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-13Teach MBP to force-merge layout successors for blocks with unanalyzableChandler Carruth
branches that also may involve fallthrough. In the case of blocks with no fallthrough, we can still re-order the blocks profitably. For example instruction decoding will in some cases continue past an indirect jump, making laying out its most likely successor there profitable. Note, no test case. I don't know how to write a test case that exercises this logic, but it matches the described desired semantics in discussions with Jakob and others. If anyone has a nice example of IR that will trigger this, that would be lovely. Also note, there are still assertion failures in real world code with this. I'm digging into those next, now that I know this isn't the cause. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144499 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-13Hoist another gross nested loop into a helper method.Chandler Carruth
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144498 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-13Add a missing doxygen comment for a helper method.Chandler Carruth
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144497 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-13Hoist a nested loop into its own method.Chandler Carruth
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144496 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-13Rewrite #3 of machine block placement. This is based somewhat on theChandler Carruth
second algorithm, but only loosely. It is more heavily based on the last discussion I had with Andy. It continues to walk from the inner-most loop outward, but there is a key difference. With this algorithm we ensure that as we visit each loop, the entire loop is merged into a single chain. At the end, the entire function is treated as a "loop", and merged into a single chain. This chain forms the desired sequence of blocks within the function. Switching to a single algorithm removes my biggest problem with the previous approaches -- they had different behavior depending on which system triggered the layout. Now there is exactly one algorithm and one basis for the decision making. The other key difference is how the chain is formed. This is based heavily on the idea Andy mentioned of keeping a worklist of blocks that are viable layout successors based on the CFG. Having this set allows us to consistently select the best layout successor for each block. It is expensive though. The code here remains very rough. There is a lot that needs to be done to clean up the code, and to make the runtime cost of this pass much lower. Very much WIP, but this was a giant chunk of code and I'd rather folks see it sooner than later. Everything remains behind a flag of course. I've added a couple of tests to exercise the issues that this iteration was motivated by: loop structure preservation. I've also fixed one test that was exhibiting the broken behavior of the previous version. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144495 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-13Prune more RALinScan. RALinScan was also here!NAKAMURA Takumi
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144487 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-13More dead code elimination in VirtRegMap.Jakob Stoklund Olesen
This thing is looking a lot like a virtual register map now. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144486 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-13Stop tracking spill slot uses in VirtRegMap.Jakob Stoklund Olesen
Nobody cared, StackSlotColoring scans the instructions to find used stack slots. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144485 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-13Remove dead code and data from VirtRegMap.Jakob Stoklund Olesen
Most of this stuff was supporting the old deferred spill code insertion mechanism. Modern spillers just edit machine code in place. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144484 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-13Stop tracking unused registers in VirtRegMap.Jakob Stoklund Olesen
The information was only used by the register allocator in StackSlotColoring. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144482 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-13Remove the -color-ss-with-regs option.Jakob Stoklund Olesen
It was off by default. The new register allocators don't have the problems that made it necessary to reallocate registers during stack slot coloring. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144481 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-13Delete VirtRegRewriter.Jakob Stoklund Olesen
And there was much rejoicing. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144480 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-13Switch PBQP to VRM's trivial rewriter.Jakob Stoklund Olesen
The very complicated VirtRegRewriter is going away. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144479 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-12Delete the old spilling framework from LiveIntervalAnalysis.Jakob Stoklund Olesen
This is dead code, all register allocators use InlineSpiller. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144478 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-12Delete the 'standard' spiller with used the old spilling framework.Jakob Stoklund Olesen
The current register allocators all use the inline spiller. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144477 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-12Switch PBQP to the modern InlineSpiller framework.Jakob Stoklund Olesen
It is worth noting that the old spiller would split live ranges around basic blocks. The new spiller doesn't do that. PBQP should do its own live range splitting with SplitEditor::splitSingleBlock() if desired. See RAGreedy::tryBlockSplit(). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144476 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-12Delete the linear scan register allocator.Jakob Stoklund Olesen
RegAllocGreedy has been the default for six months now. Deleting RegAllocLinearScan makes it possible to also delete VirtRegRewriter and clean up the spiller code. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144475 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-12The dwarf standard says that the only differences between a out-of-lineRafael Espindola
instance and a concrete inlined instance are the use of DW_TAG_subprogram instead of DW_TAG_inlined_subroutine and the who owns the tree. We were also omitting DW_AT_inline from the abstract roots. To fix this, make sure we mark abstract instance roots with DW_AT_inline even when we have only out-of-line instances referring to them with DW_AT_abstract_origin. FileCheck is not a very good tool for tests like this, maybe we should add a -verify mode to llvm-dwarfdump. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144441 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-12Don't try to form pre/post-indexed loads/stores until after LegalizeDAG ↵Eli Friedman
runs. Fixes PR11029. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144438 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-11Some cleanup and bulletproofing for node replacement in LegalizeDAG. To ↵Eli Friedman
maintain LegalizeDAG invariants, whenever we a node is replaced, we must attempt to delete it, and if it still has uses after it is replaced (which can happen in rare cases due to CSE), we must revisit it. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144432 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-11Add a custom safepoint method, in order for language implementers to decide ↵Nicolas Geoffray
which machine instruction gets to be a safepoint. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144399 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-11Initialize variable.Eric Christopher
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144360 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-11If we have a DIE with an AT_specification use that instead of the normalEric Christopher
addr DIE when adding to the dwarf accelerator tables. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144354 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-10Check in getOrCreateSubprogramDIE if a declaration exists and if so outputRafael Espindola
it first. This is a more general fix to pr11300. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144324 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-10Make types and namespaces take multiple DIEs for the accelerator tablesEric Christopher
as well. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144319 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-10Move type handling to make sure we get all created types that aren'tEric Christopher
forward decls and have names into the dwarf accelerator types table. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144306 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-10Rework adding function names to the dwarf accelerator tables, allowEric Christopher
multiple dies per function and support C++ basenames. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144304 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-10Use a bigger hammer to fix PR11314 by disabling the "forcing two-addressEvan Cheng
instruction lower optimization" in the pre-RA scheduler. The optimization, rather the hack, was done before MI use-list was available. Now we should be able to implement it in a better way, perhaps in the two-address pass until a MI scheduler is available. Now that the scheduler has to backtrack to handle call sequences. Adding artificial scheduling constraints is just not safe. Furthermore, the hack is not taking all the other scheduling decisions into consideration so it's just as likely to pessimize code. So I view disabling this optimization goodness regardless of PR11314. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144267 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-10Strip old implicit operands after foldMemoryOperand.Jakob Stoklund Olesen
The TII.foldMemoryOperand hook preserves implicit operands from the original instruction. This is not what we want when those implicit operands refer to the register being spilled. Implicit operands referring to other registers are preserved. This fixes PR11347. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144247 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-09Add check so we don't try to perform an impossible transformation. Fixes ↵Eli Friedman
issue from PR11319. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144216 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-09Add comments.Benjamin Kramer
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144194 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-09Speculatively revert commit 144124 (djg) in the hope that the 32 bitDuncan Sands
dragonegg self-host buildbot will recover (it is complaining about object files differing between different build stages). Original commit message: Add a hack to the scheduler to disable pseudo-two-address dependencies in basic blocks containing calls. This works around a problem in which these artificial dependencies can get tied up in calling seqeunce scheduling in a way that makes the graph unschedulable with the current approach of using artificial physical register dependencies for calling sequences. This fixes PR11314. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144188 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-09Take advantage of the zero byte in StringMap when emitting dwarf stringpool ↵Benjamin Kramer
entries. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144184 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-09Remove extra ';'Devang Patel
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144172 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-09Remove the pubnames section, no one consumes it.Eric Christopher
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144169 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-09Collapse DomainValues across loop back-edges.Jakob Stoklund Olesen
During the initial RPO traversal of the basic blocks, remember the ones that are incomplete because of back-edges from predecessors that haven't been visited yet. After the initial RPO, revisit all those loop headers so the incoming DomainValues on the back-edges can be properly collapsed. This will properly fix execution domains on software pipelined code, like the included test case. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144151 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-09Link to the live DomainValue after merging.Jakob Stoklund Olesen
When merging two uncollapsed DomainValues, place a link to the active DomainValue from the passive DomainValue. This allows old stale references to the passive DomainValue to be updated to point to the active DomainValue. The new resolve() function finds the active DomainValue and updates the pointer. This change makes old live-out lists more useful since they may contain uncollapsed DomainValues that have since been merged into other DomainValues. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144149 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-08Track reference count independently from clear().Jakob Stoklund Olesen
This allows clear() to be called on a DomainValue with references. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144147 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-08Call release() directly when cleaning up the remaining DomainValues.Jakob Stoklund Olesen
There is no need to involve the LiveRegs array and kill() any longer. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144133 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-08Rename all methods to follow style guide.Jakob Stoklund Olesen
No functional change. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144132 91177308-0d34-0410-b5e6-96231b3b80d8
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