aboutsummaryrefslogtreecommitdiff
path: root/lib/Transforms/Scalar/DeadStoreElimination.cpp
AgeCommit message (Collapse)Author
2009-11-10Teach DSE to eliminate useless trampolines.Duncan Sands
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86683 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-10Simplify.Nick Lewycky
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86668 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-10Reapply r86359, "Teach dead store elimination that certain intrinsics write toNick Lewycky
memory just like a store" with bug fixed (partial-overwrite.ll is the regression test). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86667 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-07Revert r86359, it is breaking the self host on theChris Lattner
llvm-gcc-i386-darwin9 build bot. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86391 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-07Teach dead store elimination that certain intrinsics write to memory just likeNick Lewycky
a store. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86359 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-04improve DSE when TargetData is not around, based on work byChris Lattner
Hans Wennborg! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86067 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-28Treat lifetime begin/end markers as allocations/frees respectively for theOwen Anderson
purposes for GVN/DSE. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85383 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-27Rename MallocFreeHelper as MemoryBuiltinsVictor Hernandez
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85286 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-26Rename MallocHelper as MallocFreeHelper, since it now also identifies calls ↵Victor Hernandez
to free() git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85181 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-26Remove FreeInst.Victor Hernandez
Remove LowerAllocations pass. Update some more passes to treate free calls just like they were treating FreeInst. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85176 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-24Auto-upgrade free instructions to calls to the builtin free function.Victor Hernandez
Update all analysis passes and transforms to treat free calls just like FreeInst. Remove RaiseAllocations and all its tests since FreeInst no longer needs to be raised. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84987 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-02fix PR4815: some cases where DeleteDeadInstruction can deleteChris Lattner
the instruction BBI points to. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80768 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-02eliminate VISIBILITY_HIDDEN from Transforms/Scalar. PR4861Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80766 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-24Fix this condition I accidentally inverted.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76988 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-24Convert several more passes to use getAnalysisIfAvailable<TargetData>()Dan Gohman
instead of getAnalysis<TargetData>(). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76982 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-09Rename PaddedSize to AllocSize, in the hope that thisDuncan Sands
will make it more obvious what it represents, and stop it being confused with the StoreSize. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71349 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-12Rename getABITypeSize to getTypePaddedSize, asDuncan Sands
suggested by Chris. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62099 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-07don't bother touching volatile stores, they will just return clobber onChris Lattner
everything interesting anyway. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60640 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-06Reimplement the inner loop of DSE. It now uniformly uses getDependence(),Chris Lattner
doesn't do its own local caching, and is slightly more aggressive about free/store dse (see testcase). This eliminates the last external client of MemDep::getDependenceFrom(). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60619 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-05Make a few major changes to memdep and its clients:Chris Lattner
1. Merge the 'None' result into 'Normal', making loads and stores return their dependencies on allocations as Normal. 2. Split the 'Normal' result into 'Clobber' and 'Def' to distinguish between the cases when memdep knows the value is produced from when we just know if may be changed. 3. Move some of the logic for determining whether readonly calls are CSEs into memdep instead of it being in GVN. This still leaves verification that the arguments are hte same to GVN to let it know about value equivalences in different contexts. 4. Change memdep's call/call dependency analysis to use getModRefInfo(CallSite,CallSite) instead of doing something very weak. This only really matters for things like DSA, but someday maybe we'll have some other decent context sensitive analyses :) 5. This reimplements the guts of memdep to handle the new results. 6. This simplifies GVN significantly: a) readonly call CSE is slightly simpler b) I eliminated the "getDependencyFrom" chaining for load elimination and load CSE doesn't have to worry about volatile (they are always clobbers) anymore. c) GVN no longer does any 'lastLoad' caching, leaving it to memdep. 7. The logic in DSE is simplified a bit and sped up. A potentially unsafe case was eliminated. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60607 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-29Fix a thinko that manifested as a crash on clamav last night.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60251 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-29Split getDependency into getDependency and getDependencyFrom, the Chris Lattner
former does caching, the later doesn't. This dramatically simplifies the logic in getDependency and getDependencyFrom. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60234 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-29Introduce and use a new MemDepResult class to hold the results of a memdepChris Lattner
query. This makes it crystal clear what cases can escape from MemDep that the clients have to handle. This also gives the clients a nice simplified interface to it that is easy to poke at. This patch also makes DepResultTy and MemoryDependenceAnalysis::DepType private, yay. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60231 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-29Reimplement the internal abstraction used by MemDep in termsChris Lattner
of a pointer/int pair instead of a manually bitmangled pointer. This forces clients to think a little more about checking the appropriate pieces and will be useful for internal implementation improvements later. I'm not particularly happy with this. After going through this I don't think that the clients of memdep should be exposed to the internal type at all. I'll fix this in a subsequent commit. This has no functionality change. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60230 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-28don't revisit instructions off the beginning of the block.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60221 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-28simplify some code, remove escaped newline.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60213 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-28rewrite a big chunk of how DSE does recursive dead operand Chris Lattner
elimination to use more modern infrastructure. Also do a bunch of small cleanups. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60201 91177308-0d34-0410-b5e6-96231b3b80d8
2008-10-01Factorize code: remove variants of "strip offDuncan Sands
pointer bitcasts and GEP's", and centralize the logic in Value::getUnderlyingObject. The difference with stripPointerCasts is that stripPointerCasts only strips GEPs if all indices are zero, while getUnderlyingObject strips GEPs no matter what the indices are. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56922 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-04Tidy up several unbeseeming casts from pointer to intptr_t.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55779 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-28Don't remove volatile loads. Thanks to Duncan for noticing this one.Owen Anderson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54144 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-28Add support for eliminating stores that store the same value that was just ↵Owen Anderson
loaded. This fixes PR2599. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54133 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-1380 col / tabs fixesNate Begeman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51021 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-13Clean up the use of static and anonymous namespaces. This turned upDan Gohman
several things that were neither in an anonymous namespace nor static but not intended to be global. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51017 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-28Fix DSE to not eliminate volatile loads with no uses.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50370 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-04Be more precise when eliminating pointers bue to memcpy's. This allows moreOwen Anderson
stores to be deleted in some cases. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46694 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-30Remove a couple more cases of "getNumUses() == 0". No need to walk the linkedNick Lewycky
list just to see if whether the list is empty. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46555 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-30Use empty() instead of comparing size() with zero.Nick Lewycky
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46554 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-30Don't DCE FreeInst's. We were using those! Patch from Owen Anderson.Nick Lewycky
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46553 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-30Make DSE much more aggressive by performing DCE earlier. Update a testcase ↵Owen Anderson
to reflect this increased aggressiveness. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46542 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-29Add support for eliminating memcpy's at the end of functions. Also fix some ↵Owen Anderson
errors I noticed in the handling of eliminating stores to byval arguments. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46494 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-25DeadStoreElimination can treat byval parameters as if there were alloca's ↵Owen Anderson
for the purpose of removing end-of-function stores. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46351 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-20Initializing an unsigned with ~0UL causes the compilerDuncan Sands
to complain on x86-64 (gcc 4.1). Use ~0U instead. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46197 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-29Remove attribution from file headers, per discussion on llvmdev.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45418 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-01Integrate the readonly/readnone logic more deeplyDuncan Sands
into alias analysis. This meant updating the API which now has versions of the getModRefBehavior, doesNotAccessMemory and onlyReadsMemory methods which take a callsite parameter. These should be used unless the callsite is not known, since in general they can do a better job than the versions that take a function. Also, users should no longer call the version of getModRefBehavior that takes both a function and a callsite. To reduce the chance of misuse it is now protected. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44487 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-06don't put erase or query for non-allocainst pointers in an set of allocainsts*'sChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43779 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-01Executive summary: getTypeSize -> getTypeStoreSize / getABITypeSize.Duncan Sands
The meaning of getTypeSize was not clear - clarifying it is important now that we have x86 long double and arbitrary precision integers. The issue with long double is that it requires 80 bits, and this is not a multiple of its alignment. This gives a primitive type for which getTypeSize differed from getABITypeSize. For arbitrary precision integers it is even worse: there is the minimum number of bits needed to hold the type (eg: 36 for an i36), the maximum number of bits that will be overwriten when storing the type (40 bits for i36) and the ABI size (i.e. the storage size rounded up to a multiple of the alignment; 64 bits for i36). This patch removes getTypeSize (not really - it is still there but deprecated to allow for a gradual transition). Instead there is: (1) getTypeSizeInBits - a number of bits that suffices to hold all values of the type. For a primitive type, this is the minimum number of bits. For an i36 this is 36 bits. For x86 long double it is 80. This corresponds to gcc's TYPE_PRECISION. (2) getTypeStoreSizeInBits - the maximum number of bits that is written when storing the type (or read when reading it). For an i36 this is 40 bits, for an x86 long double it is 80 bits. This is the size alias analysis is interested in (getTypeStoreSize returns the number of bytes). There doesn't seem to be anything corresponding to this in gcc. (3) getABITypeSizeInBits - this is getTypeStoreSizeInBits rounded up to a multiple of the alignment. For an i36 this is 64, for an x86 long double this is 96 or 128 depending on the OS. This is the spacing between consecutive elements when you form an array out of this type (getABITypeSize returns the number of bytes). This is TYPE_SIZE in gcc. Since successive elements in a SequentialType (arrays, pointers and vectors) need to be aligned, the spacing between them will be given by getABITypeSize. This means that the size of an array is the length times the getABITypeSize. It also means that GEP computations need to use getABITypeSize when computing offsets. Furthermore, if an alloca allocates several elements at once then these too need to be aligned, so the size of the alloca has to be the number of elements multiplied by getABITypeSize. Logically speaking this doesn't have to be the case when allocating just one element, but it is simpler to also use getABITypeSize in this case. So alloca's and mallocs should use getABITypeSize. Finally, since gcc's only notion of size is that given by getABITypeSize, if you want to output assembler etc the same as gcc then getABITypeSize is the size you want. Since a store will overwrite no more than getTypeStoreSize bytes, and a read will read no more than that many bytes, this is the notion of size appropriate for alias analysis calculations. In this patch I have corrected all type size uses except some of those in ScalarReplAggregates, lib/Codegen, lib/Target (the hard cases). I will get around to auditing these too at some point, but I could do with some help. Finally, I made one change which I think wise but others might consider pointless and suboptimal: in an unpacked struct the amount of space allocated for a field is now given by the ABI size rather than getTypeStoreSize. I did this because every other place that reserves memory for a type (eg: alloca) now uses getABITypeSize, and I didn't want to make an exception for unpacked structs, i.e. I did it to make things more uniform. This only effects structs containing long doubles and arbitrary precision integers. If someone wants to pack these types more tightly they can always use a packed struct. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43620 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-01Fix test/Transforms/DeadStoreElimination/PartialStore.ll, which had beenOwen Anderson
silently failing because of an incorrect run line for some time. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43605 91177308-0d34-0410-b5e6-96231b3b80d8
2007-08-26Don't DSe volatile stores.Owen Anderson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41456 91177308-0d34-0410-b5e6-96231b3b80d8
2007-08-09Make NonLocal and None const in the right way. :-)Owen Anderson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40961 91177308-0d34-0410-b5e6-96231b3b80d8
2007-08-08Change the None and NonLocal markers in memdep to be const.Owen Anderson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40946 91177308-0d34-0410-b5e6-96231b3b80d8