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path: root/llvm/lib/Transforms/IPO/InlineAlways.cpp
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* Fix a pretty scary bug I introduced into the always inliner withChandler Carruth2012-04-011-1/+1
| | | | | | | | | | a single missing character. Somehow, this had gone untested. I've added tests for returns-twice logic specifically with the always-inliner that would have caught this, and fixed the bug. Thanks to Matt for the careful review and spotting this!!! =D llvm-svn: 153832
* Give the always-inliner its own custom filter. It shouldn't have to payChandler Carruth2012-03-311-20/+63
| | | | | | | | | | | | the very high overhead of the complex inline cost analysis when all it wants to do is detect three patterns which must not be inlined. Comment the code, clean it up, and leave some hints about possible performance improvements if this ever shows up on a profile. Moving this off of the (now more expensive) inline cost analysis is particularly important because we have to run this inliner even at -O0. llvm-svn: 153814
* Remove a bunch of empty, dead, and no-op methods from all of theseChandler Carruth2012-03-311-9/+0
| | | | | | | | | | interfaces. These methods were used in the old inline cost system where there was a persistent cache that had to be updated, invalidated, and cleared. We're now doing more direct computations that don't require this intricate dance. Even if we resume some level of caching, it would almost certainly have a simpler and more narrow interface than this. llvm-svn: 153813
* Initial commit for the rewrite of the inline cost analysis to operateChandler Carruth2012-03-311-4/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | on a per-callsite walk of the called function's instructions, in breadth-first order over the potentially reachable set of basic blocks. This is a major shift in how inline cost analysis works to improve the accuracy and rationality of inlining decisions. A brief outline of the algorithm this moves to: - Build a simplification mapping based on the callsite arguments to the function arguments. - Push the entry block onto a worklist of potentially-live basic blocks. - Pop the first block off of the *front* of the worklist (for breadth-first ordering) and walk its instructions using a custom InstVisitor. - For each instruction's operands, re-map them based on the simplification mappings available for the given callsite. - Compute any simplification possible of the instruction after re-mapping, and store that back int othe simplification mapping. - Compute any bonuses, costs, or other impacts of the instruction on the cost metric. - When the terminator is reached, replace any conditional value in the terminator with any simplifications from the mapping we have, and add any successors which are not proven to be dead from these simplifications to the worklist. - Pop the next block off of the front of the worklist, and repeat. - As soon as the cost of inlining exceeds the threshold for the callsite, stop analyzing the function in order to bound cost. The primary goal of this algorithm is to perfectly handle dead code paths. We do not want any code in trivially dead code paths to impact inlining decisions. The previous metric was *extremely* flawed here, and would always subtract the average cost of two successors of a conditional branch when it was proven to become an unconditional branch at the callsite. There was no handling of wildly different costs between the two successors, which would cause inlining when the path actually taken was too large, and no inlining when the path actually taken was trivially simple. There was also no handling of the code *path*, only the immediate successors. These problems vanish completely now. See the added regression tests for the shiny new features -- we skip recursive function calls, SROA-killing instructions, and high cost complex CFG structures when dead at the callsite being analyzed. Switching to this algorithm required refactoring the inline cost interface to accept the actual threshold rather than simply returning a single cost. The resulting interface is pretty bad, and I'm planning to do lots of interface cleanup after this patch. Several other refactorings fell out of this, but I've tried to minimize them for this patch. =/ There is still more cleanup that can be done here. Please point out anything that you see in review. I've worked really hard to try to mirror at least the spirit of all of the previous heuristics in the new model. It's not clear that they are all correct any more, but I wanted to minimize the change in this single patch, it's already a bit ridiculous. One heuristic that is *not* yet mirrored is to allow inlining of functions with a dynamic alloca *if* the caller has a dynamic alloca. I will add this back, but I think the most reasonable way requires changes to the inliner itself rather than just the cost metric, and so I've deferred this for a subsequent patch. The test case is XFAIL-ed until then. As mentioned in the review mail, this seems to make Clang run about 1% to 2% faster in -O0, but makes its binary size grow by just under 4%. I've looked into the 4% growth, and it can be fixed, but requires changes to other parts of the inliner. llvm-svn: 153812
* Start removing the use of an ad-hoc 'never inline' set and insteadChandler Carruth2012-03-161-11/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | directly query the function information which this set was representing. This simplifies the interface of the inline cost analysis, and makes the always-inline pass significantly more efficient. Previously, always-inline would first make a single set of every function in the module *except* those marked with the always-inline attribute. It would then query this set at every call site to see if the function was a member of the set, and if so, refuse to inline it. This is quite wasteful. Instead, simply check the function attribute directly when looking at the callsite. The normal inliner also had similar redundancy. It added every function in the module with the noinline attribute to its set to ignore, even though inside the cost analysis function we *already tested* the noinline attribute and produced the same result. The only tricky part of removing this is that we have to be able to correctly remove only the functions inlined by the always-inline pass when finalizing, which requires a bit of a hack. Still, much less of a hack than the set of all non-always-inline functions was. While I was touching this function, I switched a heavy-weight set to a vector with sort+unique. The algorithm already had a two-phase insert and removal pattern, we were just needlessly paying the uniquing cost on every insert. This probably speeds up some compiles by a small amount (-O0 compiles with lots of always-inline, so potentially heavy libc++ users), but I've not tried to measure it. I believe there is no functional change here, but yell if you spot one. None are intended. Finally, the direction this is going in is to greatly simplify the inline cost query interface so that we can replace its implementation with a much more clever one. Along the way, all the APIs get simplified, so it seems incrementally good. llvm-svn: 152903
* Add comment.Chad Rosier2012-02-251-1/+1
| | | | llvm-svn: 151431
* Add support for disabling llvm.lifetime intrinsics in the AlwaysInliner. TheseChad Rosier2012-02-251-1/+9
| | | | | | | | are optimization hints, but at -O0 we're not optimizing. This becomes a problem when the alwaysinline attribute is abused. rdar://10921594 llvm-svn: 151429
* Fix indentation.Chad Rosier2012-02-251-2/+1
| | | | llvm-svn: 151420
* Inlining and unrolling heuristics should be aware of free truncs.Andrew Trick2011-10-011-0/+3
| | | | | | | | | | We want heuristics to be based on accurate data, but more importantly we don't want llvm to behave randomly. A benign trunc inserted by an upstream pass should not cause a wild swings in optimization level. See PR11034. It's a general problem with threshold-based heuristics, but we can make it less bad. llvm-svn: 140919
* whitespaceAndrew Trick2011-10-011-6/+6
| | | | llvm-svn: 140916
* Get rid of static constructors for pass registration. Instead, every pass ↵Owen Anderson2010-10-191-2/+7
| | | | | | | | | | | | | | | | | 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. llvm-svn: 116820
* Now with fewer extraneous semicolons!Owen Anderson2010-10-071-1/+1
| | | | llvm-svn: 115996
* Reapply r110396, with fixes to appease the Linux buildbot gods.Owen Anderson2010-08-061-1/+1
| | | | llvm-svn: 110460
* Revert r110396 to fix buildbots.Owen Anderson2010-08-061-1/+1
| | | | llvm-svn: 110410
* Don't use PassInfo* as a type identifier for passes. Instead, use the ↵Owen Anderson2010-08-051-1/+1
| | | | | | | | address of the static ID member as the sole unique type identifier. Clean up APIs related to this change. llvm-svn: 110396
* Fix batch of converting RegisterPass<> to INTIALIZE_PASS().Owen Anderson2010-07-211-2/+2
| | | | llvm-svn: 109045
* Teach the always inliner to release its inline cost estimates, like the basicNick Lewycky2010-05-151-0/+3
| | | | | | | inliner did in r103653. Why does the always inliner even bother with cost estimates anyways? llvm-svn: 103858
* Try to keep the cached inliner costs around for a bit longer for big functions.Jakob Stoklund Olesen2010-03-091-1/+4
| | | | | | | | | | | | | | | The Caller cost info would be reset everytime a callee was inlined. If the caller has lots of calls and there is some mutual recursion going on, the caller cost info could be calculated many times. This patch reduces inliner runtime from 240s to 0.5s for a function with 20000 small function calls. This is a more conservative version of r98089 that doesn't break the clang test CodeGenCXX/temp-order.cpp. That test relies on rather extreme inlining for constant folding. llvm-svn: 98099
* Revert r98089, it was breaking a clang test.Jakob Stoklund Olesen2010-03-091-4/+1
| | | | llvm-svn: 98094
* Try to keep the cached inliner costs around for a bit longer for big functions.Jakob Stoklund Olesen2010-03-091-1/+4
| | | | | | | | | | | The Caller cost info would be reset everytime a callee was inlined. If the caller has lots of calls and there is some mutual recursion going on, the caller cost info could be calculated many times. This patch reduces inliner runtime from 240s to 0.5s for a function with 20000 small function calls. llvm-svn: 98089
* Remove includes of Support/Compiler.h that are no longer needed after theNick Lewycky2009-10-251-1/+0
| | | | | | VISIBILITY_HIDDEN removal. llvm-svn: 85043
* Remove VISIBILITY_HIDDEN from class/struct found inside anonymous namespaces.Nick Lewycky2009-10-251-1/+1
| | | | | | | Chris claims we should never have visibility_hidden inside any .cpp file but that's still not true even after this commit. llvm-svn: 85042
* Move the InlineCost code from Transforms/Utils to Analysis.Dan Gohman2009-10-131-1/+1
| | | | llvm-svn: 83998
* Adjustments to last patch based on review.Dale Johannesen2009-01-091-0/+3
| | | | llvm-svn: 61969
* Do now allow InlineAlways pass to remove dead functions.Devang Patel2008-11-051-0/+3
| | | | llvm-svn: 58744
* Add InlineCost class for represent the estimated cost of inlining aDaniel Dunbar2008-10-301-1/+1
| | | | | | | | | function. - This explicitly models the costs for functions which should "always" or "never" be inlined. This fixes bugs where such costs were not previously respected. llvm-svn: 58450
* Assorted comment/naming fixes, 80-col violations, and reindentation.Daniel Dunbar2008-10-281-3/+1
| | | | | | - No functionality change. llvm-svn: 58352
* Implement function notes as function attributes. Devang Patel2008-09-261-1/+1
| | | | llvm-svn: 56716
* Large mechanical patch.Devang Patel2008-09-251-1/+1
| | | | | | | | | | | | | | | s/ParamAttr/Attribute/g s/PAList/AttrList/g s/FnAttributeWithIndex/AttributeWithIndex/g s/FnAttr/Attribute/g This sets the stage - to implement function notes as function attributes and - to distinguish between function attributes and return value attributes. This requires corresponding changes in llvm-gcc and clang. llvm-svn: 56622
* Put FN_NOTE_AlwaysInline and others in FnAttr namespace.Devang Patel2008-09-241-1/+1
| | | | llvm-svn: 56527
* Move FN_NOTE_AlwaysInline and other out of ParamAttrs namespace.Devang Patel2008-09-231-1/+1
| | | | | | Do not check isDeclaration() in hasNote(). It is clients' responsibility. llvm-svn: 56524
* Use parameter attribute store (soon to be renamed) forDevang Patel2008-09-231-1/+1
| | | | | | Function Notes also. Function notes are stored at index ~0. llvm-svn: 56511
* Add hasNote() to check note associated with a function.Devang Patel2008-09-221-1/+1
| | | | llvm-svn: 56477
* Fix typo in a comment.Devang Patel2008-09-031-1/+1
| | | | llvm-svn: 55720
* Fix comments.Devang Patel2008-09-031-2/+3
| | | | llvm-svn: 55716
* Add custom inliner that handles only functions that are marked as always_inline.Devang Patel2008-09-031-0/+70
llvm-svn: 55713
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