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2012-12-10Add a new visitor for walking the uses of a pointer value.Chandler Carruth
This visitor provides infrastructure for recursively traversing the use-graph of a pointer-producing instruction like an alloca or a malloc. It maintains a worklist of uses to visit, so it can handle very deep recursions. It automatically looks through instructions which simply translate one pointer to another (bitcasts and GEPs). It tracks the offset relative to the original pointer as long as that offset remains constant and exposes it during the visit as an APInt offset. Finally, it performs conservative escape analysis. However, currently it has some limitations that should be addressed going forward: 1) It doesn't handle vectors of pointers. 2) It doesn't provide a cheaper visitor when the constant offset tracking isn't needed. 3) It doesn't support non-instruction pointer values. The current functionality is exactly what is required to implement the SROA pointer-use visitors in terms of this one, rather than in terms of their own ad-hoc base visitor, which was always very poorly specified. SROA has been converted to use this, and the code there deleted which this utility now provides. Technically speaking, using this new visitor allows SROA to handle a few more cases than it previously did. It is now more aggressive in ignoring chains of instructions which look like they would defeat SROA, but in fact do not because they never result in a read or write of memory. While this is "neat", it shouldn't be interesting for real programs as any such chains should have been removed by others passes long before we get to SROA. As a consequence, I've not added any tests for these features -- it shouldn't be part of SROA's contract to perform such heroics. The goal is to extend the functionality of this visitor going forward, and re-use it from passes like ASan that can benefit from doing a detailed walk of the uses of a pointer. Thanks to Ben Kramer for the code review rounds and lots of help reviewing and debugging this patch. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169728 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-10Fix PR14548: SROA was crashing on a mixture of i1 and i8 loads and stores.Chandler Carruth
When SROA was evaluating a mixture of i1 and i8 loads and stores, in just a particular case, it would tickle a latent bug where we compared bits to bytes rather than bits to bits. As a consequence of the latent bug, we would allow integers through which were not byte-size multiples, a situation the later rewriting code was never intended to handle. In release builds this could trigger all manner of oddities, but the reported issue in PR14548 was forming invalid bitcast instructions. The only downside of this fix is that it makes it more clear that SROA in its current form is not capable of handling mixed i1 and i8 loads and stores. Sometimes with the previous code this would work by luck, but usually it would crash, so I'm not terribly worried. I'll watch the LNT numbers just to be sure. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169719 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-09Switch SROA to pop Uses off the back of its visitors' queues.Chandler Carruth
This will more closely match the behavior of the new PtrUseVisitor that I am adding. Hopefully this will not change the actual behavior in any way, but by making the processing order more similar help in debugging. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169697 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-09- Re-enable population count loop idiom recognization Shuxin Yang
- fix a bug which cause sigfault. - add two testing cases which was causing crash git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169687 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-08Revert the patches adding a popcount loop idiom recognition pass.Chandler Carruth
There are still bugs in this pass, as well as other issues that are being worked on, but the bugs are crashers that occur pretty easily in the wild. Test cases have been sent to the original commit's review thread. This reverts the commits: r169671: Fix a logic error. r169604: Move the popcnt tests to an X86 subdirectory. r168931: Initial commit adding the pass. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169683 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-08Fix an inadvertent typo error.Shuxin Yang
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169671 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-07s/AttrListPtr/AttributeSet/g to better label what this class is going to be ↵Bill Wendling
in the near future. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169651 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-06Set the 'MadeChange' variable if we are deleting blocks.Bill Wendling
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169455 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-04Add 'using' declarations to suppress -Woverloaded-virtual warnings.Matt Beaumont-Gay
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169214 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-03Teach the jump threading optimization to stop scanning the basic block when ↵Nadav Rotem
calculating the cost after passing the threshold. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169135 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-03Use the new script to sort the includes of every file under lib.Chandler Carruth
Sooooo many of these had incorrect or strange main module includes. I have manually inspected all of these, and fixed the main module include to be the nearest plausible thing I could find. If you own or care about any of these source files, I encourage you to take some time and check that these edits were sensible. I can't have broken anything (I strictly added headers, and reordered them, never removed), but they may not be the headers you'd really like to identify as containing the API being implemented. Many forward declarations and missing includes were added to a header files to allow them to parse cleanly when included first. The main module rule does in fact have its merits. =] git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169131 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-03Remove some buggy and apparantly unnecessary code from SROA.Chandler Carruth
The partitioning logic attempted to handle uses of an alloca with an offset starting before the alloca so long as the use had some overlap with the alloca itself. However, there was a bug where we tested '(uint64_t)Offset >= AllocSize' without first checking whether 'Offset' was positive. As a consequence, essentially every negative offset (that is, starting *before* the alloca does) would be thrown out, even if it was overlapping. The subsequent code to throw out negative offsets which were actually non-overlapping was essentially dead. The code to *handle* overlapping negative offsets was actually dead! I've just removed all of this, and taught SROA to discard any uses which start prior to the alloca from the beginning. It has the lovely property of simplifying the code. =] All the tests still pass, and in fact no new tests are needed as this is already covered by our testsuite. Fixing the code so that negative offsets work the way the comments indicate they were supposed to work causes regressions. That's how I found this. Anyways, this is all progress in the correct direction -- tightening up SROA to be maximally aggressive. Some day, I really hope to turn out-of-bounds accesses to an alloca into 'unreachable'. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169120 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-01SROA: Avoid struct and array types early to avoid creating an overly large ↵Benjamin Kramer
integer type. Fixes PR14465. Differential Revision: http://llvm-reviews.chandlerc.com/D148 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169084 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-30Replace r168930 with a more reasonable patch.Bill Wendling
The original patch removed a bunch of code that the SjLjEHPrepare pass placed into the entry block if all of the landing pads were removed during the CodeGenPrepare class. The more natural way of doing things is to run the CGP *before* we run the SjLjEHPrepare pass. Make it so! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169044 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-30Move library call simplification statistic to instcombineMeador Inge
The simplify-libcalls pass maintained a statistic to count the number of library calls that have been simplified. Now that library call simplification is being carried out in instcombine the statistic should be moved to there. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168975 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-30Move the InstVisitor utility into VMCore where it belongs. It heavilyChandler Carruth
depends on the IR infrastructure, there is no sense in it being off in Support land. This is in preparation to start working to expand InstVisitor into more special-purpose visitors that are still generic and can be re-used across different passes. The expansion will go into the Analylis tree though as nothing in VMCore needs it. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168972 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-29rdar://12100355 (part 1)Shuxin Yang
This revision attempts to recognize following population-count pattern: while(a) { c++; ... ; a &= a - 1; ... }, where <c> and <a>could be used multiple times in the loop body. TODO: On X8664 and ARM, __buildin_ctpop() are not expanded to a efficent instruction sequence, which need to be improved in the following commits. Reviewed by Nadav, really appreciate! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168931 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-29Handle the situation where CodeGenPrepare removes a reference to a BB that hasBill Wendling
the last invoke instruction in the function. This also removes the last landing pad in an function. This is fine, but with SjLj EH code, we've already placed a bunch of code in the 'entry' block, which expects the landing pad to stick around. When we get to the situation where CGP has removed the last landing pad, go ahead and nuke the SjLj instructions from the 'entry' block. <rdar://problem/12721258> git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168930 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-29instcombine: Migrate puts optimizationsMeador Inge
This patch migrates the puts optimizations from the simplify-libcalls pass into the instcombine library call simplifier. All the simplifiers from simplify-libcalls have now been migrated to instcombine. Yay! Just a few other bits to migrate (prototype attribute inference and a few statistics) and simplify-libcalls can finally be put to rest. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168925 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-29instcombine: Migrate fputs optimizationsMeador Inge
This patch migrates the fputs optimizations from the simplify-libcalls pass into the instcombine library call simplifier. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168893 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-29instcombine: Migrate fwrite optimizationsMeador Inge
This patch migrates the fwrite optimizations from the simplify-libcalls pass into the instcombine library call simplifier. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168892 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-29instcombine: Migrate fprintf optimizationsMeador Inge
This patch migrates the fprintf optimizations from the simplify-libcalls pass into the instcombine library call simplifier. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168891 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-28When we delete a dead basic block, see if any of its successors are dead andBill Wendling
delete those as well. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168829 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-27instcombine: Migrate sprintf optimizationsMeador Inge
This patch migrates the sprintf optimizations from the simplify-libcalls pass into the instcombine library call simplifier. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168677 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-26instcombine: Migrate printf optimizationsMeador Inge
This patch migrates the printf optimizations from the simplify-libcalls pass into the instcombine library call simplifier. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168604 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-26instcombine: Migrate toascii optimizationsMeador Inge
This patch migrates the toascii optimizations from the simplify-libcalls pass into the instcombine library call simplifier. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168580 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-26instcombine: Migrate isascii optimizationsMeador Inge
This patch migrates the isascii optimizations from the simplify-libcalls pass into the instcombine library call simplifier. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168579 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-26instcombine: Migrate isdigit optimizationsMeador Inge
This patch migrates the isdigit optimizations from the simplify-libcalls pass into the instcombine library call simplifier. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168578 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-26instcombine: Migrate *abs optimizationsMeador Inge
This patch migrates the *abs optimizations from the simplify-libcalls pass into the instcombine library call simplifier. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168574 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-25instcombine: Migrate ffs* optimizationsMeador Inge
This patch migrates the ffs* optimizations from the simplify-libcalls pass into the instcombine library call simplifier. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168571 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-23CodeGenPrepare: Move ret duplication out of the instruction iteration loop.Benjamin Kramer
It can delete the block, and the loop continues on free'd memory. No change in output. Found by valgrind. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168525 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-21PR14055: Implement support for sub-vector operations in SROA.Chandler Carruth
Now if we can transform an alloca into a single vector value, but it has subvector, non-element accesses, we form the appropriate shufflevectors to allow SROA to proceed. This fixes PR14055 which pointed out a very common pattern that SROA couldn't handle -- mixed vec3 and vec4 operations on a single alloca. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168418 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-20Use LLVM_ENABLE_DUMP for the variables used in printing as well as theChandler Carruth
printing functions themselves. Part of PR14324 (which should have just been a patch to the list, but hey...) git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168362 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-20Fix PR14132 and handle OOB loads speculated throuh PHI nodes.Chandler Carruth
The issue is that we may end up with newly OOB loads when speculating a load into the predecessors of a PHI node, and this confuses the new integer splitting logic in some cases, triggering an assertion failure. In fact, the branch in question must be dead code as it loads from a too-narrow alloca. Add code to handle this gracefully and leave the requisite FIXMEs for both optimizing more aggressively and doing more to aid sanitizing invalid code which triggers these patterns. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168361 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-20Add a comment to associate a FIXME with a PR where it is matters.Chandler Carruth
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168347 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-20Rework the rewriting of loads and stores for vector and integer allocasChandler Carruth
to properly handle the combinations of these with split integer loads and stores. This essentially replaces Evan's r168227 by refactoring the code in a different way, and trynig to mirror that refactoring in both the load and store sides of the rewriting. Generally speaking there was some really problematic duplicated code here that led to poorly founded assumptions and then subtle bugs. Now much of the code actually flows through and follows a more consistent style and logical path. There is still a tiny bit of duplication on the store side of things, but it is much less bad. This also changes the logic to never re-use a load or store instruction as that was simply too error prone in practice. I've added a few tests (one a reduction of the one in Evan's original patch, which happened to be the same as the report in PR14349). I'm going to look at adding a few more tests for things I found and fixed in passing (such as the volatile tests in the vectorizable predicate). This patch has survived bootstrap, and modulo one bugfix survived Duncan's test suite, but let me know if anything else explodes. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168346 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-18Remove the last bit of constant folding from LinearizeExprTree (most of it wasDuncan Sands
removed in commit 168035, but I missed this bit). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168292 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-18Fix PR14060, an infinite loop in reassociate. The problem was that one of theDuncan Sands
operands of the expression being written was wrongly thought to be reusable as an inner node of the expression resulting in it turning up as both an inner node *and* a leaf, creating a cycle in the def-use graph. This would have caused the verifier to blow up if things had gotten that far, however it managed to provoke an infinite loop first. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168291 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-17Teach SROA rewriteVectorizedStoreInst to handle cases when the loaded value ↵Evan Cheng
is narrower than the stored value. rdar://12713675 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168227 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-15Fix a crash observed by Shuxin Yang. The issue here is that LinearizeExprTree,Duncan Sands
the utility for extracting a chain of operations from the IR, thought that it might as well combine any constants it came across (rather than just returning them along with everything else). On the other hand, the factorization code would like to see the individual constants (this is quite reasonable: it is much easier to pull a factor of 3 out of 2*3 than it is to pull it out of 6; you may think 6/3 isn't so hard, but due to overflow it's not as easy to undo multiplications of constants as it may at first appear). This patch therefore makes LinearizeExprTree stupider: it now leaves optimizing to the optimization part of reassociate, and sticks to just analysing the IR. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168035 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-13instcombine: Migrate math library call simplificationsMeador Inge
This patch migrates the math library call simplifications from the simplify-libcalls pass into the instcombine library call simplifier. I have typically migrated just one simplifier at a time, but the math simplifiers are interdependent because: 1. CosOpt, PowOpt, and Exp2Opt all depend on UnaryDoubleFPOpt. 2. CosOpt, PowOpt, Exp2Opt, and UnaryDoubleFPOpt all depend on the option -enable-double-float-shrink. These two factors made migrating each of these simplifiers individually more of a pain than it would be worth. So, I migrated them all together. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167815 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-13revert r167740Shuxin Yang
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167787 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-12This change is to fix rdar://12571717 which is about assertion in ↵Shuxin Yang
Reassociate pass. The assertion is trigged when the Reassociater tries to transform expression ... + 2 * n * 3 + 2 * m + ... into: ... + 2 * (n*3 + m). In the process of the transformation, a helper routine folds the constant 2*3 into 6, confusing optimizer which is trying the to eliminate the common factor 2, and cannot find 2 any more. Review is pending. But I'd like commit first in order to help those who are waiting for this fix. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167740 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-12Delete a stale comment. No functional change.Meador Inge
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167698 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-11instcombine: Migrate memset optimizationsMeador Inge
This patch migrates the memset optimizations from the simplify-libcalls pass into the instcombine library call simplifier. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167689 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-11instcombine: Migrate memmove optimizationsMeador Inge
This patch migrates the memmove optimizations from the simplify-libcalls pass into the instcombine library call simplifier. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167687 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-11instcombine: Migrate memcpy optimizationsMeador Inge
This patch migrates the memcpy optimizations from the simplify-libcalls pass into the instcombine library call simplifier. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167686 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-11instcombine: Migrate memcmp optimizationsMeador Inge
This patch migrates the memcmp optimizations from the simplify-libcalls pass into the instcombine library call simplifier. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167683 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-11instcombine: Migrate strstr optimizationsMeador Inge
This patch migrates the strstr optimizations from the simplify-libcalls pass into the instcombine library call simplifier. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167682 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-10instcombine: Migrate strcspn optimizationsMeador Inge
This patch migrates the strcspn optimizations from the simplify-libcalls pass into the instcombine library call simplifier. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167675 91177308-0d34-0410-b5e6-96231b3b80d8