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path: root/lib/CodeGen/SplitKit.cpp
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2010-11-10No need to add liveness that's already there.Jakob Stoklund Olesen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118742 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-10Basic rematerialization during splitting.Jakob Stoklund Olesen
Whenever splitting wants to insert a copy, it checks if the value can be rematerialized cheaply instead. Missing features: - Delete instructions when all uses have been rematerialized. - Truncate live ranges to the remaining uses after rematerialization. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118702 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-03Tag debug output as regallocJakob Stoklund Olesen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118193 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-01When inserting copies during splitting, always use the parent register as theJakob Stoklund Olesen
source, and let rewrite() clean it up. This way, kill flags on the inserted copies are fixed as well during rewrite(). We can't just assume that all the copies we insert are going to be kills since critical edges into loop headers sometimes require both source and dest to be live out of a block. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117980 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-01Update kill flags while rewriting instructions after splitting.Jakob Stoklund Olesen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117959 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-30Make sure copies are inserted after any exception handling labels at the top ofJakob Stoklund Olesen
a basic block. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117764 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-29Don't transfer unused values to the new intervals formed by splitting.Jakob Stoklund Olesen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117673 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-29Silence Release build warnings.Benjamin Kramer
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117671 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-29Never propagate the idom value out of a block that defines its own value.Jakob Stoklund Olesen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117669 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-28Replace SplitKit SSA update with an iterative algorithm very similar to the oneJakob Stoklund Olesen
in SSAUpdaterImpl.h Verifying live intervals revealed that the old method was completely wrong, and we need an iterative approach to calculating PHI placemant. Fortunately, we have MachineDominators available, so we don't have to compute that over and over like SSAUpdaterImpl.h must. Live-out values are cached between calls to mapValue() and computed in a greedy way, so most calls will be working with very small block sets. Thanks to Bob for explaining how this should work. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117599 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-28Make MachineDominators available for SplitEditor. We are going to need it forJakob Stoklund Olesen
proper SSA updating. This doesn't cause MachineDominators to be recomputed since we are already requiring MachineLoopInfo which uses dominators as well. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117598 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-27Handle critical loop predecessors by making both inside and outside registersJakob Stoklund Olesen
live out. This doesn't prevent us from inserting a loop preheader later on, if that is better. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117424 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-27Compute critical loop predecessors in the same way as critical loop exits.Jakob Stoklund Olesen
Critical edges going into a loop are not as bad as critical exits. We can handle them by splitting the critical edge, or by having both inside and outside registers live out of the predecessor. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117423 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-26After splitting, compute connected components of all new registers, not just forJakob Stoklund Olesen
the remainder register. Example: bb0: x = 1 bb1: use(x) ... x = 2 jump bb1 When x is isolated in bb1, the inner part breaks into two components, x1 and x2: bb0: x0 = 1 bb1: x1 = x0 use(x1) ... x2 = 2 x0 = x2 jump bb1 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117408 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-26Call RenumberValues for all new registers created during splitting. This isJakob Stoklund Olesen
necessary to get correct hasPHIKill flags. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117406 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-26Preserve PHIDef bits in cloned values during splitting.Jakob Stoklund Olesen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117405 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-22Be more strict about detecting multi-use blocks for isolation.Jakob Stoklund Olesen
When a block has exactly two uses and the register is both live-in and live-out, don't isolate the block. We would be inserting two copies, so we haven't really made any progress. If the live-in and live-out values separate into disconnected components after splitting, we would be making progress. We can't detect that for now. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117169 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-22Be more strict when detecting critical edges before loop splitting.Jakob Stoklund Olesen
An exit block with a critical edge must only have predecessors in the loop, or just before the loop. This guarantees that the inserted copies in the loop predecessors dominate the exit block. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117144 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-22Add print methodsJakob Stoklund Olesen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117143 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-21Don't include the destination interval in the union when computingJakob Stoklund Olesen
Parent - union(Y, ...). Doh. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117042 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-15Eliminate curli from SplitEditor. Use the LiveRangeEdit reference instead.Jakob Stoklund Olesen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116547 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-15Move stack slot assignments into LiveRangeEdit.Jakob Stoklund Olesen
All registers created during splitting or spilling are assigned to the same stack slot as the parent register. When splitting or rematting, we may not spill at all. In that case the stack slot is still assigned, but it will be dead. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116546 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-14Create a new LiveRangeEdit class to keep track of the new registers created whenJakob Stoklund Olesen
splitting or spillling, and to help with rematerialization. Use LiveRangeEdit in InlineSpiller and SplitKit. This will eventually make it possible to share remat code between InlineSpiller and SplitKit. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116543 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-14Only split around a loop if the live range has uses outside the loop periphery.Jakob Stoklund Olesen
Before we would also split around a loop if any peripheral block had multiple uses. This could cause repeated splitting when splitting a different live range would insert uses into the periphery. Now -spiller=inline passes the nightly test suite again. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116494 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-08Rename SplitEditor::rewrite to finish() and break it out into a couple of newJakob Stoklund Olesen
functions: computeRemainder and rewrite. When the remainder breaks up into multiple components, remember to rewrite those uses as well. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116121 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-07After splitting, the remaining LiveInterval may be fragmented into multipleJakob Stoklund Olesen
connected components. These components should be allocated different virtual registers because there is no reason for them to be allocated together. Add the ConnectedVNInfoEqClasses class to calculate the connected components, and move values to new LiveIntervals. Use it from SplitKit::rewrite by creating new virtual registers for the components. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116006 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-07Print more loop info.Jakob Stoklund Olesen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115951 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-07Print out MBB number when rewriting.Jakob Stoklund Olesen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115950 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-07Cache interval iterators in SplitEditor::addTruncSimpleRange so we only have toJakob Stoklund Olesen
do one find(). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115929 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-07Clean up debug printing.Jakob Stoklund Olesen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115928 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-05Count uses in all nested loops, not just the deepest.Jakob Stoklund Olesen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115710 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-05Remove SplitAnalysis::removeUse. It was only used to make SplitAnalysisJakob Stoklund Olesen
reusable, but that is no longer relevant since a split will always replace the original. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115709 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-05dupli always has an interval now.Jakob Stoklund Olesen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115708 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-05We can split around loops with multiple exits now.Jakob Stoklund Olesen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115696 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-05Update SplitEditor API to reflect the fact that the original live interval isJakob Stoklund Olesen
never kept after splitting. Keeping the original interval made sense when the split region doesn't modify the register, and the original is spilled. We can get the same effect by detecting reloaded values when spilling around copies. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115695 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-05Intervals are half-open.Jakob Stoklund Olesen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115694 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-05When we find a reaching definition, make sure it is visited from all paths byJakob Stoklund Olesen
erasing it from the visited set. That ensures we create the right phi defs. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115666 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-05Don't use nextIndex to check for live out of instruction.Jakob Stoklund Olesen
Insert copy after defining instruction. Fix LiveIntervalMap::extendTo to properly handle live segments starting before the current basic block. Make sure the open live range is extended to the inserted copy's use slot. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115665 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-25Removed VNInfo::isDefAccurate(). Def "accuracy" can be checked by testing ↵Lang Hames
whether LiveIntervals::getInstructionFromIndex(def) returns NULL. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114791 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-21Build the complement interval dupli after the split intervals instead ofJakob Stoklund Olesen
creating it before and subtracting split ranges. This way, the SSA update code in LiveIntervalMap can properly create and use new phi values in dupli. Now it is possible to create split regions where a value escapes along two different CFG edges, creating phi values outside the split region. This is a work in progress and probably quite broken. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114492 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-16Use the value mapping provided by LiveIntervalMap. This simplifies the code aJakob Stoklund Olesen
great deal because we don't have to worry about maintaining SSA form. Unconditionally copy back to dupli when the register is live out of the split range, even if the live-out value was defined outside the range. Skipping the back-copy only makes sense when the live range is going to spill outside the split range, and we don't know that it will. Besides, this was a hack to avoid SSA update issues. Clear up some confusion about the end point of a half-open LiveRange. Methinks LiveRanges need to be closed so both start and end are included in the range. The low bits of a SlotIndex are symbolic, so a half-open range doesn't really make sense. This would be a pervasive change, though. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114043 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-13Mechanically replace LiveInterval* with LiveIntervalMap for intervals beingJakob Stoklund Olesen
edited without actually using LiveIntervalMap functionality. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113816 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-13Allow LiveIntervalMap to be reused by resetting the current live interval.Jakob Stoklund Olesen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113815 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-13Let's just declare that it is impossible to construct a std::pair from a nullJakob Stoklund Olesen
pointer and work around that. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113788 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-19Fix the msvc 2010 build.Michael J. Spencer
The Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 16.00.30319.01 implements parts of C++0x based on the draft standard. An old version of the draft had a bug that makes std::pair<T1*, T2*>(something, 0) fail to compile. This is because the template<class U, class V> pair(U&& x, V&& y) constructor is selected, even though it later fails to implicitly convert U and V to frist_type and second_type. This has been fixed in n3090, but it seems that Microsoft is not going to update msvc. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111535 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-18Thinking about it, we don't need MachineDominatorTree after all. The DomValueJakob Stoklund Olesen
map discovers the iterated dominance frontier for free. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111400 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-18Revert r111394. It was too aggressive.Jakob Stoklund Olesen
We must complete the DFS, otherwise we might miss needed phi-defs, and prematurely color live ranges with a non-dominating value. This is not a big deal since we get to color more of the CFG and the next mapValue call will be faster. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111397 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-18Aggressively prune the DFS when inserting phi-defs.Jakob Stoklund Olesen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111394 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-18Add the LiveIntervalMap class. Don't hook it up yet.Jakob Stoklund Olesen
LiveIntervalMap maps values from a parent LiveInterval to a child interval that is a strict subset. It will create phi-def values as needed to preserve the VNInfo SSA form in the child interval. This leads to an algorithm very similar to the one in SSAUpdaterImpl.h, but with enough differences that the code can't be reused: - We don't need to manipulate PHI instructions. - LiveIntervals have kills. - We have MachineDominatorTree. - We can use df_iterator. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111393 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-13Clean up the Spiller.h interface.Jakob Stoklund Olesen
The earliestStart argument is entirely specific to linear scan allocation, and can be easily calculated by RegAllocLinearScan. Replace std::vector with SmallVector. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111055 91177308-0d34-0410-b5e6-96231b3b80d8
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