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2012-09-28Do not delete BBs if their addresses are taken. rdar://12396696Evan Cheng
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164866 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-28CorrelatedPropagation: BasicBlock::removePredecessor can simplify PHI nodes. ↵Benjamin Kramer
If the it's the condition of a SwitchInst, reload it. Fixes PR13972. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164818 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-26Remove the `hasFnAttr' method from Function.Bill Wendling
The hasFnAttr method has been replaced by querying the Attributes explicitly. No intended functionality change. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164725 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-26Analogous fix to memset and memcpy rewriting. Don't have a test caseChandler Carruth
contrived for these yet, as I spotted them by inspection and the test cases are a bit more tricky to phrase. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164691 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-26When rewriting the pointer operand to a load or store which hasChandler Carruth
alignment guarantees attached, re-compute the alignment so that we consider offsets which impact alignment. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164690 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-26Teach all of the loads, stores, memsets and memcpys created by theChandler Carruth
rewriter in SROA to carry a proper alignment. This involves interrogating various sources of alignment, etc. This is a more complete and principled fix to PR13920 as well as related bugs pointed out by Eli in review and by inspection in the area. Also by inspection fix the integer and vector promotion paths to create aligned loads and stores. I still need to work up test cases for these... Sorry for the delay, they were found purely by inspection. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164689 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-26Revert the business end of r164636 and try again. I'll come in again. ;]Chandler Carruth
This should really, really fix PR13916. For real this time. The underlying bug is... a bit more subtle than I had imagined. The setup is a code pattern that leads to an @llvm.memcpy call with two equal pointers to an alloca in the source and dest. Now, not any pattern will do. The alloca needs to be formed just so, and both pointers should be wrapped in different bitcasts etc. When this precise pattern hits, a funny sequence of events transpires. First, we correctly detect the potential for overlap, and correctly optimize the memcpy. The first time. However, we do simplify the set of users of the alloca, and that causes us to run the alloca back through the SROA pass in case there are knock-on simplifications. At this point, a curious thing has happened. If we happen to have an i8 alloca, we have direct i8 pointer values. So we don't bother creating a cast, we rewrite the arguments to the memcpy to dircetly refer to the alloca. Now, in an unrelated area of the pass, we have clever logic which ensures that when visiting each User of a particular pointer derived from an alloca, we only visit that User once, and directly inspect all of its operands which refer to that particular pointer value. However, the mechanism used to detect memcpy's with the potential to overlap relied upon getting visited once per *Use*, not once per *User*. This is always true *unless* the same exact value is both source and dest. It turns out that almost nothing actually produces that pattern though. We can hand craft test cases that more directly test this behavior of course, and those are included. Also, note that there is a significant missed optimization here -- we prove in many cases that there is a non-volatile memcpy call with identical source and dest addresses. We shouldn't prevent splitting the alloca in that case, and in fact we should just remove such memcpy calls eagerly. I'll address that in a subsequent commit. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164669 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-25Don't drop the alignment on a memcpy intrinsic when producing a store. This isNick Lewycky
only a missed optimization opportunity if the store is over-aligned, but a miscompile if the store's new type has a higher natural alignment than the memcpy did. Fixes PR13920! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164641 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-25Revert the business end of r164634, and replace it with a different fix. TheNick Lewycky
reason we were getting two of the same alloca is because of a memmove/memcpy which had the same alloca in both the src and dest. Now we detect that case directly. This has the same testcase as before, but fixes a clang test CodeGenObjC/exceptions.m which runs clang -O2. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164636 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-25Don't try to promote the same alloca twice. Fixes PR13916!Nick Lewycky
Chandler, it's not obvious that it's okay that this alloca gets into the list twice to begin with. Please review and see whether this is the fix you really want, but I wanted to get a fix checked in quickly. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164634 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-25Fix a case where SROA did not correctly detect dead PHI or selects dueChandler Carruth
to chains or cycles between PHIs and/or selects. Also add a couple of really nice test cases reduced from Kostya's reports in PR13905 and PR13906. Both are fixed by this patch. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164596 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-25Fix a crash in SROA. This was reported independently by Takumi andChandler Carruth
David (I think), but I would appreciate folks verifying that this fixes the big crasher. I'm still working on a reduced test case, but because this was causing problems I wanted to get the fix checked in quickly. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164585 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-25Don't forget that strcpy and friends return a pointer to the destination, soNick Lewycky
it's not a dead store if that pointer is used. Whoops! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164583 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-24Remove unused name of variable to quiet a warning. Also canonicalize aNick Lewycky
declaration to use the same form as in the rest of the file. No functionality change. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164576 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-24Teach DSE that strcpy, strncpy, strcat and strncat are all stores which may beNick Lewycky
dead. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164561 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-24Move all the calls to AA.getTargetLibraryInfo() to using a TLI member variable.Nick Lewycky
No functionality change. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164560 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-24Address one of the original FIXMEs for the new SROA pass by implementingChandler Carruth
integer promotion analogous to vector promotion. When there is an integer alloca being accessed both as its integer type and as a narrower integer type, promote the narrower access to "insert" and "extract" the smaller integer from the larger one, and make the integer alloca a candidate for promotion. In the new formulation, we don't care about target legal integer or use thresholds to control things. Instead, we only perform this promotion to an integer type which the frontend has already emitted a load or store for. This bounds the scope and prevents optimization passes from coalescing larger and larger entities into a single integer. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164479 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-23Switch to a signed representation for the dynamic offsets while walkingChandler Carruth
across the uses of the alloca. It's entirely possible for negative numbers to come up here, and in some rare cases simply doing the 2's complement arithmetic isn't the correct decision. Notably, we can't zext the index of the GEP. The definition of GEP is that these offsets are sign extended or truncated to the size of the pointer, and then wrapping 2's complement arithmetic used. This patch fixes an issue that comes up with *no* input from the buildbots or bootstrap afaict. The only place where it manifested, disturbingly, is Clang's own regression test suite. A reduced and targeted collection of tests are added to cope with this. Note that I've tried to pin down the potential cases of overflow, but may have missed some cases. I've tried to add a few cases to test this, but its hard because LLVM has quite limited support for >64bit constructs. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164475 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-21Fix a case where the new SROA pass failed to zap dead operands toChandler Carruth
selects with a constant condition. This resulted in the operands remaining live through the SROA rewriter. Most of the time, this just caused some dead allocas to persist and get zapped by later passes, but in one case found by Joerg, it caused a crash when we tried to *promote* the alloca despite it having this dead use. We already have the mechanisms in place to handle this, just wire select up to them. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164427 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-21LoopIdiom: Give up when the loop is not in canonical form.Benjamin Kramer
We rely on it when doing the transforms. This can happen when there is an indirectbr in the loop. Fixes PR13892. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164383 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-19CodeGenPrep: turn lookup tables into switches for some targets.Hans Wennborg
This is a follow-up from r163302, which added a transformation to SimplifyCFG that turns some switches into loads from lookup tables. It was pointed out that some targets, such as GPUs and deeply embedded targets, might not find this appropriate, but SimplifyCFG doesn't have enough information about the target to decide this. This patch adds the reverse transformation to CodeGenPrep: it turns loads from lookup tables back into switches for targets where we do not build jump tables (assuming these are also the targets where lookup tables are inappropriate). Hopefully we will eventually get to have target information in SimplifyCFG, and then this CodeGenPrep transformation can be removed. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164206 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-18Fix the last crasher I've gotten a reproduction for in SROA. This oneChandler Carruth
from the dragonegg build bots when we turned on the full version of the pass. Included a much reduced test case for this pesky bug, despite bugpoint's uncooperative behavior. Also, I audited all the similar code I could find and didn't spot any other cases where this mistake cropped up. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164178 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-18LSR critical edge splitting fix for PR13756.Andrew Trick
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164147 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-18Fix getCommonType in a different way from the way I fixed it whenChandler Carruth
working on FCA splitting. Instead of refusing to form a common type when there are uses of a subsection of the alloca as well as a use of the entire alloca, just skip the subsection uses and continue looking for a whole-alloca use with a type that we can use. This produces slightly prettier IR I think, and also fixes the other failure in the test. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164146 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-18Fix build for compilers that don't understand injected class names properly.Benjamin Kramer
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164142 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-18SROA: Use CRTP for OpSplitter to get rid of virtual dispatch and the ↵Benjamin Kramer
virtual-dtor warnings that come with it. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164140 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-18SROA: Replace the member function template contraption for recursively ↵Benjamin Kramer
splitting aggregates into a real class. No intended functionality change. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164135 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-18SROA.cpp: Appease msvc.NAKAMURA Takumi
...I don't know why this could appease msvc...baad. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164130 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-18Fix a warning in release builds and a test case I forgot to update withChandler Carruth
a fix to getCommonType in the previous patch. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164120 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-18Add a major missing piece to the new SROA pass: aggressive splitting ofChandler Carruth
FCAs. This is essential in order to promote allocas that are used in struct returns by frontends like Clang. The FCA load would block the rest of the pass from firing, resulting is significant regressions with the bullet benchmark in the nightly test suite. Thanks to Duncan for repeated discussions about how best to do this, and to both him and Benjamin for review. This appears to have blocked many places where the pass tries to fire, and so I'm expect somewhat different results with this fix added. As with the last big patch, I'm including a change to enable the SROA by default *temporarily*. Ben is going to remove this as soon as the LNT bots pick up the patch. I'm just trying to get a round of LNT numbers from the stable machines in the lab. NOTE: Four clang tests are expected to fail in the brief window where this is enabled. Sorry for the noise! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164119 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-18Mark unimplemented copy constructors and copy assignment operators as ↵Craig Topper
LLVM_DELETED_FUNCTION. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164090 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-17NewSROA: Provide a full set of operator< for ByteRanges.Benjamin Kramer
MSVC8 won't compile lower_bound if one is missing. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164035 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-16Refactor the SROA visitors for partitioning an alloca and buildingChandler Carruth
partition use lists a bit. No functionality changed. These visitors are actually visiting a tuple of a Use and an offset into the alloca. However, we use the InstVisitor to handle the dispatch over the users, and so the Use and Offset are stored in class member variables and set just before each call to visit(). This is fairly awkward and makes the functions a bit harder to read, but its the only real option we have until InstVisitor can be rewritten to use variadic templates. However, this pattern shouldn't be followed on the helper member functions where there is no interface constraint from the visitor. We already were passing the instruction as a normal parameter rather than use the Use to get at it, start passing the offset as well. This will become more important in subsequent patches as the offset will in some cases change while visiting a single instruction. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164003 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-15Use LLVM_DELETED_FUNCTION in place of 'DO NOT IMPLEMENT' comments.Craig Topper
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163974 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-15Port the SSAUpdater-based promotion logic from the old SROA pass to theChandler Carruth
new one, and add support for running the new pass in that mode and in that slot of the pass manager. With this the new pass can completely replace the old one within the pipeline. The strategy for enabling or disabling the SSAUpdater logic is to do it by making the requirement of the domtree analysis optional. By default, it is required and we get the standard mem2reg approach. This is usually the desired strategy when run in stand-alone situations. Within the CGSCC pass manager, we disable requiring of the domtree analysis and consequentially trigger fallback to the SSAUpdater promotion. In theory this would allow the pass to re-use a domtree if one happened to be available even when run in a mode that doesn't require it. In practice, it lets us have a single pass rather than two which was simpler for me to wrap my head around. There is a hidden flag to force the use of the SSAUpdater code path for the purpose of testing. The primary testing strategy is just to run the existing tests through that path. One notable difference is that it has custom code to handle lifetime markers, and one of the tests has been enhanced to exercise that code. This has survived a bootstrap and the test suite without serious correctness issues, however my run of the test suite produced *very* alarming performance numbers. I don't entirely understand or trust them though, so more investigation is on-going. To aid my understanding of the performance impact of the new SROA now that it runs throughout the optimization pipeline, I'm enabling it by default in this commit, and will disable it again once the LNT bots have picked up one iteration with it. I want to get those bots (which are much more stable) to evaluate the impact of the change before I jump to any conclusions. NOTE: Several Clang tests will fail because they run -O3 and check the result's order of output. They'll go back to passing once I disable it again. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163965 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-14Stylistic and 80-col fixesEvan Cheng
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163940 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-14Fix 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); * use \param instead of \arg to document parameters in order to be consistent with the rest of the codebase. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163902 91177308-0d34-0410-b5e6-96231b3b80d8
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
2012-09-14Remove 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