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path: root/lib/CodeGen/IfConversion.cpp
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2010-11-06Prune includes.Benjamin Kramer
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118342 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-03Two sets of changes. Sorry they are intermingled.Evan Cheng
1. Fix pre-ra scheduler so it doesn't try to push instructions above calls to "optimize for latency". Call instructions don't have the right latency and this is more likely to use introduce spills. 2. Fix if-converter cost function. For ARM, it should use instruction latencies, not # of micro-ops since multi-latency instructions is completely executed even when the predicate is false. Also, some instruction will be "slower" when they are predicated due to the register def becoming implicit input. rdar://8598427 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118135 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-26When the "true" and "false" blocks of a diamond if-conversion are the same,Bob Wilson
do not double-count the duplicate instructions by counting once from the beginning and again from the end. Keep track of where the duplicates from the beginning ended and don't go past that point when counting duplicates at the end. Radar 8589805. This change causes one of the MC/ARM/simple-fp-encoding tests to produce different (better!) code without the vmovne instruction being tested. I changed the test to produce vmovne and vmoveq instructions but moving between register files in the opposite direction. That's not quite the same but predicated versions of those instructions weren't being tested before, so at least the test coverage is not any worse, just different. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117333 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-26Change if-conversion to keep track of the extra cost due to microcodedBob Wilson
instructions separately from the count of non-predicated instructions. The instruction count is used in places to determine how many instructions to copy, predicate, etc. and things get confused if that count includes the extra cost for microcoded ops. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117332 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
2010-10-01Thread the determination of branch prediction hit rates back through the ↵Owen Anderson
if-conversion heuristic APIs. For now, stick with a constant estimate of 90% (branch predictors are good!), but we might find that we want to provide more nuanced estimates in the future. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115364 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-29Silence msvc warnings.Benjamin Kramer
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115097 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-28Give the if-converter access to MachineLoopInfo, and use it to generate ↵Owen Anderson
plausible branch prediction estimates. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114981 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-28Part one of switching to using a more sane heuristic for determining ↵Owen Anderson
if-conversion profitability. Rather than having arbitrary cutoffs, actually try to cost model the conversion. For now, the constants are tuned to more or less match our existing behavior, but these will be changed to reflect realistic values as this work proceeds. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114973 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-10Teach if-converter to be more careful with predicating instructions that wouldEvan Cheng
take multiple cycles to decode. For the current if-converter clients (actually only ARM), the instructions that are predicated on false are not nops. They would still take machine cycles to decode. Micro-coded instructions such as LDM / STM can potentially take multiple cycles to decode. If-converter should take treat them as non-micro-coded simple instructions. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113570 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
2010-07-21Fix 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
2010-06-29Reapply my if-conversion cleanup from svn r106939 with fixes.Bob Wilson
There are 2 changes relative to the previous version of the patch: 1) For the "simple" if-conversion case, there's no need to worry about RemoveExtraEdges not handling an unanalyzable branch. Predicated terminators are ignored in this context, so RemoveExtraEdges does the right thing. This might break someday if we ever treat indirect branches (BRIND) as predicable, but for now, I just removed this part of the patch, because in the case where we do not add an unconditional branch, we rely on keeping the fall-through edge to CvtBBI (which is empty after this transformation). The change relative to the previous patch is: @@ -1036,10 +1036,6 @@ IterIfcvt = false; } - // RemoveExtraEdges won't work if the block has an unanalyzable branch, - // which is typically the case for IfConvertSimple, so explicitly remove - // CvtBBI as a successor. - BBI.BB->removeSuccessor(CvtBBI->BB); RemoveExtraEdges(BBI); // Update block info. BB can be iteratively if-converted. 2) My patch exposed a bug in the code for merging the tail of a "diamond", which had previously never been exercised. The code was simply checking that the tail had a single predecessor, but there was a case in MultiSource/Benchmarks/VersaBench/dbms where that single predecessor was neither edge of the diamond. I added the following change to check for that: @@ -1276,7 +1276,18 @@ // tail, add a unconditional branch to it. if (TailBB) { BBInfo TailBBI = BBAnalysis[TailBB->getNumber()]; - if (TailBB->pred_size() == 1 && !TailBBI.HasFallThrough) { + bool CanMergeTail = !TailBBI.HasFallThrough; + // There may still be a fall-through edge from BBI1 or BBI2 to TailBB; + // check if there are any other predecessors besides those. + unsigned NumPreds = TailBB->pred_size(); + if (NumPreds > 1) + CanMergeTail = false; + else if (NumPreds == 1 && CanMergeTail) { + MachineBasicBlock::pred_iterator PI = TailBB->pred_begin(); + if (*PI != BBI1->BB && *PI != BBI2->BB) + CanMergeTail = false; + } + if (CanMergeTail) { MergeBlocks(BBI, TailBBI); TailBBI.IsDone = true; } else { With these fixes, I was able to run all the SingleSource and MultiSource tests successfully. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107110 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-28new, no longer brain-dead, r106907Jim Grosbach
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107060 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-28Revert r106907, "make sure to handle dbg_value instructions in the middle of theDaniel Dunbar
block, not...", it caused a bunch of nightly test regressions. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107009 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-26Revert my if-conversion cleanup since it caused a bunch of nightly testBob Wilson
regressions. --- Reverse-merging r106939 into '.': U test/CodeGen/Thumb2/thumb2-ifcvt3.ll U lib/CodeGen/IfConversion.cpp git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106951 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-26Clean up some problems with extra CFG edges being introduced duringBob Wilson
if-conversion. The RemoveExtraEdges function doesn't work for blocks that end with unanalyzable branches, so in those cases, the "extra" edges must be explicitly removed. The CopyAndPredicateBlock and MergeBlocks methods can also avoid copying successor edges due to branches that have already been removed. The latter case is especially helpful when MergeBlocks is called for handling "diamond" if-conversions, where otherwise you can end up with some weird intermediate states in the CFG. Unfortunately I've been unable to find cases where this cleanup actually makes a significant difference in the code. There is one test where we manage to remove an empty block at the end of a function. Radar 6911268. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106939 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-25make sure to handle dbg_value instructions in the middle of the block, notJim Grosbach
just at the head, when doing diamond if-conversion. rdar://7797940 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106907 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-25Change if-conversion block size limit checks to add some flexibility.Evan Cheng
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106901 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-2580 column and typo fixJim Grosbach
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106894 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-22Use pre-increment instead of post-increment when the result is not used.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106542 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-19Tidy.Bob Wilson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106383 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-18Allow ARM if-converter to be run after post allocation scheduling.Evan Cheng
- This fixed a number of bugs in if-converter, tail merging, and post-allocation scheduler. If-converter now runs branch folding / tail merging first to maximize if-conversion opportunities. - Also changed the t2IT instruction slightly. It now defines the ITSTATE register which is read by instructions in the IT block. - Added Thumb2 specific hazard recognizer to ensure the scheduler doesn't change the instruction ordering in the IT block (since IT mask has been finalized). It also ensures no other instructions can be scheduled between instructions in the IT block. This is not yet enabled. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106344 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-18Fix an inverted condition.Evan Cheng
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106330 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-18Teach iff-converter to properly count # of dups. It was not skipping over ↵Evan Cheng
dbg_value's which resulted in non-duplicated instructions being deleted. rdar://8104384. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106323 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-18Fix PR7372: Conditional branches (at least on ARM) are treated as predicated,Bob Wilson
so when IfConverter::CopyAndPredicateBlock checks to see if it should ignore an instruction because it is a branch, it should not check if the branch is predicated. This case (when IgnoreBr is true) is only relevant from IfConvertTriangle, where new branches are inserted after the block has been copied and predicated. If the original branch is not removed, we end up with multiple conditional branches (possibly conflicting) at the end of the block. Aside from any immediate errors resulting from that, this confuses the AnalyzeBranch functions so that the branches are not analyzable. That in turn causes the IfConverter to think that the "Simple" pattern can be applied, and things go downhill fast because the "Simple" pattern does _not_ apply if the block can fall through. This is pretty fragile. If there are other degenerate cases where AnalyzeBranch fails, but where the block may still fall through, the IfConverter should not perform its "Simple" if-conversion. But, I don't know how to do that with the current AnalyzeBranch interface, so for now, the best thing seems to be to avoid creating branches that AnalyzeBranch cannot handle. Evan, please review! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106291 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-17Add a DebugLoc parameter to TargetInstrInfo::InsertBranch(). ThisStuart Hastings
addresses a longstanding deficiency noted in many FIXMEs scattered across all the targets. This effectively moves the problem up one level, replacing eleven FIXMEs in the targets with eight FIXMEs in CodeGen, plus one path through FastISel where we actually supply a DebugLoc, fixing Radar 7421831. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106243 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-16Make post-ra scheduling, anti-dep breaking, and register scavenger ↵Evan Cheng
(conservatively) aware of predicated instructions. This enables ARM to move if-conversion before post-ra scheduler. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106091 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-15Fix 80col violations, remove trailing whitespace, and clarify a comment.Bob Wilson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106057 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-15IfConversion's AnalyzeBlocks method always returns false; clean it up.Bob Wilson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106027 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-15Fix a comment typo.Bob Wilson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106015 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-14More dbg_value cleanup so the presence of debug info doesn't affect code-gen.Jim Grosbach
Make sure to skip the dbg_value instructions when moving dups out of the diamond. rdar://7797940 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105965 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-07Cleanup. Process the dbg_values separatelyJim Grosbach
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105554 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-07Move exit check where it really belongs.Jim Grosbach
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105541 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-04Make if-conversion ignore dbg_value instructions in its analysis. rdar://7797940Jim Grosbach
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105498 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-04Change errs() to dbgs().David Greene
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92520 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-21Allow target to disable if-converting predicable instructions. e.g. NEON ↵Evan Cheng
instructions under ARM mode. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89541 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
2009-10-27Record CodeGen optimization level in the BranchFolding pass so that we canBob Wilson
use it to control tail merging when there is a tradeoff between performance and code size. When there is only 1 instruction in the common tail, we have been merging. That can be good for code size but is a definite loss for performance. Now we will avoid tail merging in that case when the optimization level is "Aggressive", i.e., "-O3". Radar 7338114. Since the IfConversion pass invokes BranchFolding, it too needs to know the optimization level. Note that I removed the RegisterPass instantiation for IfConversion because it required a default constructor. If someone wants to keep that for some reason, we can add a default constructor with a hard-wired optimization level. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85346 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-25Remove VISIBILITY_HIDDEN from class/struct found inside anonymous namespaces.Nick Lewycky
Chris claims we should never have visibility_hidden inside any .cpp file but that's still not true even after this commit. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85042 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-04Run branch folding if if-converter make some transformations.Evan Cheng
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80994 91177308-0d34-0410-b5e6-96231b3b80d8
2009-08-23remove various std::ostream version of printing methods fromChris Lattner
MachineInstr and MachineOperand. This required eliminating a bunch of stuff that was using DOUT, I hope that bill doesn't mind me stealing his fun. ;-) git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79813 91177308-0d34-0410-b5e6-96231b3b80d8
2009-08-22Convert DOUT to DEBUG(errs()...).Bill Wendling
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79751 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-25More migration to raw_ostream, the water has dried up around the iostream hole.Daniel Dunbar
- Some clients which used DOUT have moved to DEBUG. We are deprecating the "magic" DOUT behavior which avoided calling printing functions when the statement was disabled. In addition to being unnecessary magic, it had the downside of leaving code in -Asserts builds, and of hiding potentially unnecessary computations. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77019 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-14llvm_unreachable->llvm_unreachable(0), LLVM_UNREACHABLE->llvm_unreachable.Torok Edwin
This adds location info for all llvm_unreachable calls (which is a macro now) in !NDEBUG builds. In NDEBUG builds location info and the message is off (it only prints "UREACHABLE executed"). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75640 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-12Fix assert(0) conversion, as suggested by Chris.Torok Edwin
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75423 91177308-0d34-0410-b5e6-96231b3b80d8
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