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2012-09-14SROA: Silence unused variable warnings in Release builds.Benjamin Kramer
The NDEBUG hack is ugly, but I see no better solution. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163900 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-14Rework the computation of a sub-structure natural type. There wereChandler Carruth
pointless checks in here, bad asserts, and just confusing code. I've also added a bit more to the comment to clarify what this function is really trying to do as it was not obvious to Duncan when studying it. Thanks to Duncan for helping me dig through the issue. No real functionality changed here in practical cases, and certainly no test case. This is just cleanup spotted by inspection. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163897 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-14Rely on the recursive check for pointer types rather than adding anChandler Carruth
explicit check before recursing. A simplification requested by Duncan during review. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163896 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-14Be a bit more aggressive in bailing out of this routine. Spotted byChandler Carruth
inspection by Duncan during review. My suspicion is that we would still have returned 0 anyways in this case, but doing it sooner is better. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163895 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-14Add some comments clarifying that the GEP analysis for vector GEPs isChandler Carruth
deeply suspicious and likely to go away eventually. Also fix a bogus comment about one of the checks in the vector GEP analysis. Based on review from Duncan. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163894 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-14Move an instance variable to a local variable based on review by Duncan.Chandler Carruth
Originally I had anticipated needing to thread this through more bits of the SROA pass itself, but that ended up not happening. In the end, this is a much simpler way to manange the variable. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163893 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-14Add a comment about debug intrinsics that I *really* don't want toChandler Carruth
forget from Duncan's review as a FIXME. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163892 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-14Add two asserts that Duncan thought would help ensure things don't rotChandler Carruth
unexpectedly in the future. More fixes from his code review. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163891 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-14Actually keep the flag default-off for now. =/ That's what I get forChandler Carruth
being busy testing this... git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163890 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-14Remove some dead, commented out code Duncan spotted in review.Chandler Carruth
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163889 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-14Wrap the dumping and printing routines in NDEBUG and LLVM_ENABLE_DUMP macros.Chandler Carruth
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163888 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-14Lots of comment fixes and cleanups from Duncan's review.Chandler Carruth
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163887 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-14SROA.cpp: Unbreak gcc, sorry!NAKAMURA Takumi
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163886 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-14SROA.cpp: Appease msvc. LLVM_ATTRIBUTE(s) should come front of "const".NAKAMURA Takumi
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163885 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-14Speculative change to try to fix older GCC versions that can't handleChandler Carruth
the injected class name of a dependent base class here. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163884 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-14Introduce a new SROA implementation.Chandler Carruth
This is essentially a ground up re-think of the SROA pass in LLVM. It was initially inspired by a few problems with the existing pass: - It is subject to the bane of my existence in optimizations: arbitrary thresholds. - It is overly conservative about which constructs can be split and promoted. - The vector value replacement aspect is separated from the splitting logic, missing many opportunities where splitting and vector value formation can work together. - The splitting is entirely based around the underlying type of the alloca, despite this type often having little to do with the reality of how that memory is used. This is especially prevelant with unions and base classes where we tail-pack derived members. - When splitting fails (often due to the thresholds), the vector value replacement (again because it is separate) can kick in for preposterous cases where we simply should have split the value. This results in forming i1024 and i2048 integer "bit vectors" that tremendously slow down subsequnet IR optimizations (due to large APInts) and impede the backend's lowering. The new design takes an approach that fundamentally is not susceptible to many of these problems. It is the result of a discusison between myself and Duncan Sands over IRC about how to premptively avoid these types of problems and how to do SROA in a more principled way. Since then, it has evolved and grown, but this remains an important aspect: it fixes real world problems with the SROA process today. First, the transform of SROA actually has little to do with replacement. It has more to do with splitting. The goal is to take an aggregate alloca and form a composition of scalar allocas which can replace it and will be most suitable to the eventual replacement by scalar SSA values. The actual replacement is performed by mem2reg (and in the future SSAUpdater). The splitting is divided into four phases. The first phase is an analysis of the uses of the alloca. This phase recursively walks uses, building up a dense datastructure representing the ranges of the alloca's memory actually used and checking for uses which inhibit any aspects of the transform such as the escape of a pointer. Once we have a mapping of the ranges of the alloca used by individual operations, we compute a partitioning of the used ranges. Some uses are inherently splittable (such as memcpy and memset), while scalar uses are not splittable. The goal is to build a partitioning that has the minimum number of splits while placing each unsplittable use in its own partition. Overlapping unsplittable uses belong to the same partition. This is the target split of the aggregate alloca, and it maximizes the number of scalar accesses which become accesses to their own alloca and candidates for promotion. Third, we re-walk the uses of the alloca and assign each specific memory access to all the partitions touched so that we have dense use-lists for each partition. Finally, we build a new, smaller alloca for each partition and rewrite each use of that partition to use the new alloca. During this phase the pass will also work very hard to transform uses of an alloca into a form suitable for promotion, including forming vector operations, speculating loads throguh PHI nodes and selects, etc. After splitting is complete, each newly refined alloca that is a candidate for promotion to a scalar SSA value is run through mem2reg. There are lots of reasonably detailed comments in the source code about the design and algorithms, and I'm going to be trying to improve them in subsequent commits to ensure this is well documented, as the new pass is in many ways more complex than the old one. Some of this is still a WIP, but the current state is reasonbly stable. It has passed bootstrap, the nightly test suite, and Duncan has run it successfully through the ACATS and DragonEgg test suites. That said, it remains behind a default-off flag until the last few pieces are in place, and full testing can be done. Specific areas I'm looking at next: - Improved comments and some code cleanup from reviews. - SSAUpdater and enabling this pass inside the CGSCC pass manager. - Some datastructure tuning and compile-time measurements. - More aggressive FCA splitting and vector formation. Many thanks to Duncan Sands for the thorough final review, as well as Benjamin Kramer for lots of review during the process of writing this pass, and Daniel Berlin for reviewing the data structures and algorithms and general theory of the pass. Also, several other people on IRC, over lunch tables, etc for lots of feedback and advice. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163883 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-13Handle the new !tbaa.struct metadata tags when converting a memcpy into scalarDan Gohman
loads and stores. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163844 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-13Extract code for reducing a type to a single value type into a helper function.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163817 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-13MemCpyOpt: When forming a memset from stores also take GEP constexprs into ↵Benjamin Kramer
account. This is common when storing to global variables. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163809 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-13Fix an 80 char line limit.Nadav Rotem
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163808 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-13Use Nick's suggestion of storing a large NULL into the GV instead of memset, ↵Bill Wendling
which requires TargetData. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163799 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-13Fix Doxygen issues:Dmitri Gribenko
* wrap code blocks in \code ... \endcode; * refer to parameter names in paragraphs correctly (\arg is not what most people want -- it starts a new paragraph). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163790 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-13Introduce the __llvm_gcov_flush function.Bill Wendling
This function writes out the current values of the counters and then resets them. This can be used similarly to the __gcov_flush function to sync the counters when need be. For instance, in a situation where the application doesn't exit. <rdar://problem/12185886> git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163757 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-12Detect overflow in the path count computation. rdar://12277446.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163739 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-12PGO: preserve branch-weight metadata when removing a case which jumpsManman Ren
to the default target. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163724 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-12Release build: guard dump functions withManman Ren
"#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)" No functional change. Update r163344. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163679 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-11SimplifyCFG: preserve branch-weight metadata when creating a new switch fromManman Ren
a pair of switch/branch where both depend on the value of the same variable and the default case of the first switch/branch goes to the second switch/branch. Code clean up and fixed a few issues: 1> handling the case where some cases of the 2nd switch are invalidated 2> correctly calculate the weight for the 2nd switch when it is a conditional eq Testing case is modified from Alastair's original patch. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163635 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-11llvm/lib/Transforms/Utils/CMakeLists.txt: Update.NAKAMURA Takumi
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163593 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-11Add a pass that renames everything with metasyntatic names. This works well ↵Alex Rosenberg
after using bugpoint to reduce the confusion presented by the original names, which no longer mean what they used to. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163592 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-10Move bypassSlowDivision into the llvm namespace.Benjamin Kramer
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163503 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-10Fix style issues from r163302 pointed out by Evan.Hans Wennborg
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163491 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-09Move spaces to the right places. No functionality change.Nick Lewycky
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163485 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-09DSE: Poking holes into a SetVector is expensive, avoid it if possible.Benjamin Kramer
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163480 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-08Remove an incorrect assert during branch weight propagation.Andrew Trick
Patch and test case by Alastair Murray! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163437 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-07SimplifyCFG: ValidLookupTableConstant should be staticHans Wennborg
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163378 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-06Release build: guard dump functions with "ifndef NDEBUG"Manman Ren
No functional change. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163344 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-06Fix switch_to_lookup_table.ll test from r163302.Hans Wennborg
The lookup tables did not get built in a deterministic order. This makes them get built in the order that the corresponding phi nodes were found. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163305 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-06Build lookup tables for switches (PR884)Hans Wennborg
This adds a transformation to SimplifyCFG that attemps to turn switch instructions into loads from lookup tables. It works on switches that are only used to initialize one or more phi nodes in a common successor basic block, for example: int f(int x) { switch (x) { case 0: return 5; case 1: return 4; case 2: return -2; case 5: return 7; case 6: return 9; default: return 42; } This speeds up the code by removing the hard-to-predict jump, and reduces code size by removing the code for the jump targets. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163302 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-06Update function names to conform to guidelines.Jim Grosbach
No functional change. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163279 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-05Stop casting away const qualifier needlessly.Roman Divacky
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163258 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-05[asan] fix lintKostya Serebryany
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163205 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-05[asan] extend the blacklist functionality to handle global-init. Patch by ↵Kostya Serebryany
Reid Watson git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163199 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-04Make provenance checking conservative in cases whenDan Gohman
pointers-to-strong-pointers may be in play. These can lead to retains and releases happening in unstructured ways, foiling the optimizer. This fixes rdar://12150909. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163180 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-04BypassSlowDivision: Assign to reference, don't copy the object.Jakub Staszak
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163179 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-04Fix my previous patch (r163164). It does now what it is supposed to do:Jakub Staszak
Doesn't set MadeChange to TRUE if BypassSlowDivision doesn't change anything. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163165 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-04Return false if BypassSlowDivision doesn't change anything.Jakub Staszak
Also a few minor changes: - use pre-inc instead of post-inc - use isa instead of dyn_cast - 80 col - trailing spaces git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163164 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-04Generic Bypass Slow DivPreston Gurd
- CodeGenPrepare pass for identifying div/rem ops - Backend specifies the type mapping using addBypassSlowDivType - Enabled only for Intel Atom with O2 32-bit -> 8-bit - Replace IDIV with instructions which test its value and use DIVB if the value is positive and less than 256. - In the case when the quotient and remainder of a divide are used a DIV and a REM instruction will be present in the IR. In the non-Atom case they are both lowered to IDIVs and CSE removes the redundant IDIV instruction, using the quotient and remainder from the first IDIV. However, due to this optimization CSE is not able to eliminate redundant IDIV instructions because they are located in different basic blocks. This is overcome by calculating both the quotient (DIV) and remainder (REM) in each basic block that is inserted by the optimization and reusing the result values when a subsequent DIV or REM instruction uses the same operands. - Test cases check for the presents of the optimization when calculating either the quotient, remainder, or both. Patch by Tyler Nowicki! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163150 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-04LICM may hoist an instruction with undefined behavior above a trap.Nadav Rotem
Scan the body of the loop and find instructions that may trap. Use this information when deciding if it is safe to hoist or sink instructions. Notice that we can optimize the search of instructions that may throw in the case of nested loops. rdar://11518836 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163132 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-02Not all targets have efficient ISel code generation for select instructions.Nadav Rotem
For example, the ARM target does not have efficient ISel handling for vector selects with scalar conditions. This patch adds a TLI hook which allows the different targets to report which selects are supported well and which selects should be converted to CF duting codegen prepare. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163093 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-02LoopRotation: Make the brute force DomTree update more brute force.Benjamin Kramer
We update until we hit a fixpoint. This is probably slow but also slightly simplifies the code. It should also fix the occasional invalid domtrees observed when building with expensive checking. I couldn't find a case where this had a measurable slowdown, but if someone finds a pathological case where it does we may have to find a cleverer way of updating dominators here. Thanks to Duncan for the test case. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163091 91177308-0d34-0410-b5e6-96231b3b80d8
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