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* Reland: Dead Virtual Function EliminationOliver Stannard2019-10-178-0/+685
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove dead virtual functions from vtables with replaceNonMetadataUsesWith, so that CGProfile metadata gets cleaned up correctly. Original commit message: Currently, it is hard for the compiler to remove unused C++ virtual functions, because they are all referenced from vtables, which are referenced by constructors. This means that if the constructor is called from any live code, then we keep every virtual function in the final link, even if there are no call sites which can use it. This patch allows unused virtual functions to be removed during LTO (and regular compilation in limited circumstances) by using type metadata to match virtual function call sites to the vtable slots they might load from. This information can then be used in the global dead code elimination pass instead of the references from vtables to virtual functions, to more accurately determine which functions are reachable. To make this transformation safe, I have changed clang's code-generation to always load virtual function pointers using the llvm.type.checked.load intrinsic, instead of regular load instructions. I originally tried writing this using clang's existing code-generation, which uses the llvm.type.test and llvm.assume intrinsics after doing a normal load. However, it is possible for optimisations to obscure the relationship between the GEP, load and llvm.type.test, causing GlobalDCE to fail to find virtual function call sites. The existing linkage and visibility types don't accurately describe the scope in which a virtual call could be made which uses a given vtable. This is wider than the visibility of the type itself, because a virtual function call could be made using a more-visible base class. I've added a new !vcall_visibility metadata type to represent this, described in TypeMetadata.rst. The internalization pass and libLTO have been updated to change this metadata when linking is performed. This doesn't currently work with ThinLTO, because it needs to see every call to llvm.type.checked.load in the linkage unit. It might be possible to extend this optimisation to be able to use the ThinLTO summary, as was done for devirtualization, but until then that combination is rejected in the clang driver. To test this, I've written a fuzzer which generates random C++ programs with complex class inheritance graphs, and virtual functions called through object and function pointers of different types. The programs are spread across multiple translation units and DSOs to test the different visibility restrictions. I've also tried doing bootstrap builds of LLVM to test this. This isn't ideal, because only classes in anonymous namespaces can be optimised with -fvisibility=default, and some parts of LLVM (plugins and bugpoint) do not work correctly with -fvisibility=hidden. However, there are only 12 test failures when building with -fvisibility=hidden (and an unmodified compiler), and this change does not cause any new failures for either value of -fvisibility. On the 7 C++ sub-benchmarks of SPEC2006, this gives a geomean code-size reduction of ~6%, over a baseline compiled with "-O2 -flto -fvisibility=hidden -fwhole-program-vtables". The best cases are reductions of ~14% in 450.soplex and 483.xalancbmk, and there are no code size increases. I've also run this on a set of 8 mbed-os examples compiled for Armv7M, which show a geomean size reduction of ~3%, again with no size increases. I had hoped that this would have no effect on performance, which would allow it to awlays be enabled (when using -fwhole-program-vtables). However, the changes in clang to use the llvm.type.checked.load intrinsic are causing ~1% performance regression in the C++ parts of SPEC2006. It should be possible to recover some of this perf loss by teaching optimisations about the llvm.type.checked.load intrinsic, which would make it worth turning this on by default (though it's still dependent on -fwhole-program-vtables). Differential revision: https://reviews.llvm.org/D63932 llvm-svn: 375094
* Revert "Dead Virtual Function Elimination"Jorge Gorbe Moya2019-10-148-685/+0
| | | | | | This reverts commit 9f6a873268e1ad9855873d9d8007086c0d01cf4f. llvm-svn: 374844
* Dead Virtual Function EliminationOliver Stannard2019-10-118-0/+685
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, it is hard for the compiler to remove unused C++ virtual functions, because they are all referenced from vtables, which are referenced by constructors. This means that if the constructor is called from any live code, then we keep every virtual function in the final link, even if there are no call sites which can use it. This patch allows unused virtual functions to be removed during LTO (and regular compilation in limited circumstances) by using type metadata to match virtual function call sites to the vtable slots they might load from. This information can then be used in the global dead code elimination pass instead of the references from vtables to virtual functions, to more accurately determine which functions are reachable. To make this transformation safe, I have changed clang's code-generation to always load virtual function pointers using the llvm.type.checked.load intrinsic, instead of regular load instructions. I originally tried writing this using clang's existing code-generation, which uses the llvm.type.test and llvm.assume intrinsics after doing a normal load. However, it is possible for optimisations to obscure the relationship between the GEP, load and llvm.type.test, causing GlobalDCE to fail to find virtual function call sites. The existing linkage and visibility types don't accurately describe the scope in which a virtual call could be made which uses a given vtable. This is wider than the visibility of the type itself, because a virtual function call could be made using a more-visible base class. I've added a new !vcall_visibility metadata type to represent this, described in TypeMetadata.rst. The internalization pass and libLTO have been updated to change this metadata when linking is performed. This doesn't currently work with ThinLTO, because it needs to see every call to llvm.type.checked.load in the linkage unit. It might be possible to extend this optimisation to be able to use the ThinLTO summary, as was done for devirtualization, but until then that combination is rejected in the clang driver. To test this, I've written a fuzzer which generates random C++ programs with complex class inheritance graphs, and virtual functions called through object and function pointers of different types. The programs are spread across multiple translation units and DSOs to test the different visibility restrictions. I've also tried doing bootstrap builds of LLVM to test this. This isn't ideal, because only classes in anonymous namespaces can be optimised with -fvisibility=default, and some parts of LLVM (plugins and bugpoint) do not work correctly with -fvisibility=hidden. However, there are only 12 test failures when building with -fvisibility=hidden (and an unmodified compiler), and this change does not cause any new failures for either value of -fvisibility. On the 7 C++ sub-benchmarks of SPEC2006, this gives a geomean code-size reduction of ~6%, over a baseline compiled with "-O2 -flto -fvisibility=hidden -fwhole-program-vtables". The best cases are reductions of ~14% in 450.soplex and 483.xalancbmk, and there are no code size increases. I've also run this on a set of 8 mbed-os examples compiled for Armv7M, which show a geomean size reduction of ~3%, again with no size increases. I had hoped that this would have no effect on performance, which would allow it to awlays be enabled (when using -fwhole-program-vtables). However, the changes in clang to use the llvm.type.checked.load intrinsic are causing ~1% performance regression in the C++ parts of SPEC2006. It should be possible to recover some of this perf loss by teaching optimisations about the llvm.type.checked.load intrinsic, which would make it worth turning this on by default (though it's still dependent on -fwhole-program-vtables). Differential revision: https://reviews.llvm.org/D63932 llvm-svn: 374539
* [IR] Disallow llvm.global_ctors and llvm.global_dtors of the 2-field form in ↵Fangrui Song2019-05-152-3/+3
| | | | | | | | | | | | | | | | | | | | textual format The 3-field form was introduced by D3499 in 2014 and the legacy 2-field form was planned to be removed in LLVM 4.0 For the textual format, this patch migrates the existing 2-field form to use the 3-field form and deletes the compatibility code. test/Verifier/global-ctors-2.ll checks we have a friendly error message. For bitcode, lib/IR/AutoUpgrade UpgradeGlobalVariables will upgrade the 2-field form (add i8* null as the third field). Reviewed By: rnk, dexonsmith Differential Revision: https://reviews.llvm.org/D61547 llvm-svn: 360742
* Revert "Temporarily Revert "Add basic loop fusion pass.""Eric Christopher2019-04-1719-0/+563
| | | | | | | | The reversion apparently deleted the test/Transforms directory. Will be re-reverting again. llvm-svn: 358552
* Temporarily Revert "Add basic loop fusion pass."Eric Christopher2019-04-1719-563/+0
| | | | | | | | As it's causing some bot failures (and per request from kbarton). This reverts commit r358543/ab70da07286e618016e78247e4a24fcb84077fda. llvm-svn: 358546
* GlobalDCE: Teach isEmptyFunction() to ignore debug intrinsics.Adrian Prantl2018-11-161-1/+24
| | | | | | | This fixes PR39669. https://bugs.llvm.org/show_bug.cgi?id=39669 llvm-svn: 347065
* [PM] Teach the PGO instrumentation pasess to run GlobalDCE beforeChandler Carruth2017-05-251-5/+14
| | | | | | | | | | | | | | | | | | | | | instrumenting code. This is important in the new pass manager. The old pass manager's inliner has a small DCE routine embedded within it. The new pass manager relies on the actual GlobalDCE pass for this. Without this patch, instrumentation profiling with the new PM results in massive code bloat in the object files because the instrumentation itself ends up preventing DCE from working to remove the code. We should probably change the instrumentation (and/or DCE) so that we can eliminate dead code even if instrumented, but we shouldn't even spend the time generating instrumentation for that code so this still seems like a good patch. Differential Revision: https://reviews.llvm.org/D33535 llvm-svn: 303845
* [PH] Replace uses of AssertingVH from members of analysis results withChandler Carruth2017-01-241-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | a lazy-asserting PoisoningVH. AssertVH is fundamentally incompatible with cache-invalidation of analysis results. The invaliadtion happens after the AssertingVH has already fired. Instead, use a PoisoningVH that will assert if the dangling handle is ever used rather than merely be assigned or destroyed. This patch also removes all of the (numerous) doomed attempts to work around this fundamental incompatibility. It is a pretty significant simplification IMO. The most interesting change is in the Inliner where we still do some clearing because we don't want to rely on the coarse grained invalidation strategy of the containing pass manager. However, I prefer the approach that contains this logic to the cleanup phase of the Inliner, and I think we could enhance the CGSCC analysis management layer to make this even better in the future if desired. The rest is straight cleanup. I've also added a test for one of the harder cases to work around: when a *module analysis* contains many AssertingVHes pointing at functions. Differential Revision: https://reviews.llvm.org/D29006 llvm-svn: 292928
* [PM] Replace the hard invalidate in JumpThreading for LVI with correctChandler Carruth2017-01-231-0/+23
| | | | | | | | | | | | | | | | | | | | | invalidation of deleted functions in GlobalDCE. This was always testing a bug really triggered in GlobalDCE. Right now we have analyses with asserting value handles into IR. As long as those remain, when *deleting* an IR unit, we cannot wait for the normal invalidation scheme to kick in even though it was designed to work correctly in the face of these kinds of deletions. Instead, the pass needs to directly handle invalidating the analysis results pointing at that IR unit. I've tought the Inliner about this and this patch teaches GlobalDCE. This will handle the asserting VH case in the existing test as well as other issues of the same fundamental variety. I've moved the test into the GlobalDCE directory and added a comment explaining what is going on. Note that we cannot simply require LVI here because LVI is too lazy. llvm-svn: 292773
* Test the different scenarios of GlobalDCE and comdats moreChandler Carruth2016-12-262-17/+178
| | | | | | | | | | | | | | | | | | | | | | | | | systematically and document in the test what all is going on. This replaces the PR-named test that was the only coverage for GlobalDCE and comdats previously. I wrote this because I wasn't certain how comdat DCE was supposed to work and wanted to step through what GlobalDCE did to fully understand it. After talking to folks and reading the code and really staring at things it all makes sense but it seemed good to help write down some of this in a more explicit and fully covering test case. For example, it seemed like a bug that GlobalDCE didn't consider comdat participation of ifuncs. Specifically it seemed like an accident because testing didn't really cover that case. But in fact, ifuncs specifically cannot participate in a comdat despite having that API. The new test case covers this and explicitly documents that DCE gets to fire here even though there are comdats involved. Also, we didn't have any positive tests for the challenging cases such as usage cycles between comdat participants that might make them seem alive except that there is no external edge into the cycle. llvm-svn: 290537
* [GlobalDCE, Misc] Don't remove functions referenced by ifuncsDavid Majnemer2016-05-041-0/+13
| | | | | | | | | | | | We forgot to consider the target of ifuncs when considering if a function was alive or dead. N.B. Also update a few auxiliary tools like bugpoint and verify-uselistorder. This fixes PR27593. llvm-svn: 268468
* [IPO/GlobalDCE] Port to the new pass manager.Davide Italiano2016-05-031-1/+1
| | | | | | Differential Revision: http://reviews.llvm.org/D19782 llvm-svn: 268425
* [GlobalDCE] Modernize. Use FileCheck instead of grep.Davide Italiano2016-05-016-7/+15
| | | | llvm-svn: 268207
* [opaque pointer type] Add textual IR support for explicit type parameter for ↵David Blaikie2015-09-113-10/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | global aliases update.py: import fileinput import sys import re alias_match_prefix = r"(.*(?:=|:|^)\s*(?:external |)(?:(?:private|internal|linkonce|linkonce_odr|weak|weak_odr|common|appending|extern_weak|available_externally) )?(?:default |hidden |protected )?(?:dllimport |dllexport )?(?:unnamed_addr |)(?:thread_local(?:\([a-z]*\))? )?alias" plain = re.compile(alias_match_prefix + r" (.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|addrspacecast|\[\[[a-zA-Z]|\{\{).*$)") cast = re.compile(alias_match_prefix + r") ((?:bitcast|inttoptr|addrspacecast)\s*\(.* to (.*?)(| addrspace\(\d+\) *)\*\)\s*(?:;.*)?$)") gep = re.compile(alias_match_prefix + r") ((?:getelementptr)\s*(?:inbounds)?\s*\((?P<type>.*), (?P=type)(?:\s*addrspace\(\d+\)\s*)?\* .*\)\s*(?:;.*)?$)") def conv(line): m = re.match(cast, line) if m: return m.group(1) + " " + m.group(3) + ", " + m.group(2) m = re.match(gep, line) if m: return m.group(1) + " " + m.group(3) + ", " + m.group(2) m = re.match(plain, line) if m: return m.group(1) + ", " + m.group(2) + m.group(3) + "*" + m.group(4) + "\n" return line for line in sys.stdin: sys.stdout.write(conv(line)) apply.sh: for name in "$@" do python3 `dirname "$0"`/update.py < "$name" > "$name.tmp" && mv "$name.tmp" "$name" rm -f "$name.tmp" done The actual commands: From llvm/src: find test/ -name *.ll | xargs ./apply.sh From llvm/src/tools/clang: find test/ -name *.mm -o -name *.m -o -name *.cpp -o -name *.c | xargs -I '{}' ../../apply.sh "{}" From llvm/src/tools/polly: find test/ -name *.ll | xargs ./apply.sh llvm-svn: 247378
* [opaque pointer type] Add textual IR support for explicit type parameter to ↵David Blaikie2015-04-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | the call instruction See r230786 and r230794 for similar changes to gep and load respectively. Call is a bit different because it often doesn't have a single explicit type - usually the type is deduced from the arguments, and just the return type is explicit. In those cases there's no need to change the IR. When that's not the case, the IR usually contains the pointer type of the first operand - but since typed pointers are going away, that representation is insufficient so I'm just stripping the "pointerness" of the explicit type away. This does make the IR a bit weird - it /sort of/ reads like the type of the first operand: "call void () %x(" but %x is actually of type "void ()*" and will eventually be just of type "ptr". But this seems not too bad and I don't think it would benefit from repeating the type ("void (), void () * %x(" and then eventually "void (), ptr %x(") as has been done with gep and load. This also has a side benefit: since the explicit type is no longer a pointer, there's no ambiguity between an explicit type and a function that returns a function pointer. Previously this case needed an explicit type (eg: a function returning a void() function was written as "call void () () * @x(" rather than "call void () * @x(" because of the ambiguity between a function returning a pointer to a void() function and a function returning void). No ambiguity means even function pointer return types can just be written alone, without writing the whole function's type. This leaves /only/ the varargs case where the explicit type is required. Given the special type syntax in call instructions, the regex-fu used for migration was a bit more involved in its own unique way (as every one of these is) so here it is. Use it in conjunction with the apply.sh script and associated find/xargs commands I've provided in rr230786 to migrate your out of tree tests. Do let me know if any of this doesn't cover your cases & we can iterate on a more general script/regexes to help others with out of tree tests. About 9 test cases couldn't be automatically migrated - half of those were functions returning function pointers, where I just had to manually delete the function argument types now that we didn't need an explicit function type there. The other half were typedefs of function types used in calls - just had to manually drop the * from those. import fileinput import sys import re pat = re.compile(r'((?:=|:|^|\s)call\s(?:[^@]*?))(\s*$|\s*(?:(?:\[\[[a-zA-Z0-9_]+\]\]|[@%](?:(")?[\\\?@a-zA-Z0-9_.]*?(?(3)"|)|{{.*}}))(?:\(|$)|undef|inttoptr|bitcast|null|asm).*$)') addrspace_end = re.compile(r"addrspace\(\d+\)\s*\*$") func_end = re.compile("(?:void.*|\)\s*)\*$") def conv(match, line): if not match or re.search(addrspace_end, match.group(1)) or not re.search(func_end, match.group(1)): return line return line[:match.start()] + match.group(1)[:match.group(1).rfind('*')].rstrip() + match.group(2) + line[match.end():] for line in sys.stdin: sys.stdout.write(conv(re.search(pat, line), line)) llvm-svn: 235145
* [opaque pointer type] Add textual IR support for explicit type parameter to ↵David Blaikie2015-03-132-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | gep operator Similar to gep (r230786) and load (r230794) changes. Similar migration script can be used to update test cases, which successfully migrated all of LLVM and Polly, but about 4 test cases needed manually changes in Clang. (this script will read the contents of stdin and massage it into stdout - wrap it in the 'apply.sh' script shown in previous commits + xargs to apply it over a large set of test cases) import fileinput import sys import re rep = re.compile(r"(getelementptr(?:\s+inbounds)?\s*\()((<\d*\s+x\s+)?([^@]*?)(|\s*addrspace\(\d+\))\s*\*(?(3)>)\s*)(?=$|%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|zeroinitializer|<|\[\[[a-zA-Z]|\{\{)", re.MULTILINE | re.DOTALL) def conv(match): line = match.group(1) line += match.group(4) line += ", " line += match.group(2) return line line = sys.stdin.read() off = 0 for match in re.finditer(rep, line): sys.stdout.write(line[off:match.start()]) sys.stdout.write(conv(match)) off = match.end() sys.stdout.write(line[off:]) llvm-svn: 232184
* [opaque pointer type] Add textual IR support for explicit type parameter to ↵David Blaikie2015-02-275-11/+11
| | | | | | | | | | | | | | | | | | | | | | | | load instruction Essentially the same as the GEP change in r230786. A similar migration script can be used to update test cases, though a few more test case improvements/changes were required this time around: (r229269-r229278) import fileinput import sys import re pat = re.compile(r"((?:=|:|^)\s*load (?:atomic )?(?:volatile )?(.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$)") for line in sys.stdin: sys.stdout.write(re.sub(pat, r"\1, \2\3*\4", line)) Reviewers: rafael, dexonsmith, grosser Differential Revision: http://reviews.llvm.org/D7649 llvm-svn: 230794
* [opaque pointer type] Add textual IR support for explicit type parameter to ↵David Blaikie2015-02-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | getelementptr instruction One of several parallel first steps to remove the target type of pointers, replacing them with a single opaque pointer type. This adds an explicit type parameter to the gep instruction so that when the first parameter becomes an opaque pointer type, the type to gep through is still available to the instructions. * This doesn't modify gep operators, only instructions (operators will be handled separately) * Textual IR changes only. Bitcode (including upgrade) and changing the in-memory representation will be in separate changes. * geps of vectors are transformed as: getelementptr <4 x float*> %x, ... ->getelementptr float, <4 x float*> %x, ... Then, once the opaque pointer type is introduced, this will ultimately look like: getelementptr float, <4 x ptr> %x with the unambiguous interpretation that it is a vector of pointers to float. * address spaces remain on the pointer, not the type: getelementptr float addrspace(1)* %x ->getelementptr float, float addrspace(1)* %x Then, eventually: getelementptr float, ptr addrspace(1) %x Importantly, the massive amount of test case churn has been automated by same crappy python code. I had to manually update a few test cases that wouldn't fit the script's model (r228970,r229196,r229197,r229198). The python script just massages stdin and writes the result to stdout, I then wrapped that in a shell script to handle replacing files, then using the usual find+xargs to migrate all the files. update.py: import fileinput import sys import re ibrep = re.compile(r"(^.*?[^%\w]getelementptr inbounds )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))") normrep = re.compile( r"(^.*?[^%\w]getelementptr )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))") def conv(match, line): if not match: return line line = match.groups()[0] if len(match.groups()[5]) == 0: line += match.groups()[2] line += match.groups()[3] line += ", " line += match.groups()[1] line += "\n" return line for line in sys.stdin: if line.find("getelementptr ") == line.find("getelementptr inbounds"): if line.find("getelementptr inbounds") != line.find("getelementptr inbounds ("): line = conv(re.match(ibrep, line), line) elif line.find("getelementptr ") != line.find("getelementptr ("): line = conv(re.match(normrep, line), line) sys.stdout.write(line) apply.sh: for name in "$@" do python3 `dirname "$0"`/update.py < "$name" > "$name.tmp" && mv "$name.tmp" "$name" rm -f "$name.tmp" done The actual commands: From llvm/src: find test/ -name *.ll | xargs ./apply.sh From llvm/src/tools/clang: find test/ -name *.mm -o -name *.m -o -name *.cpp -o -name *.c | xargs -I '{}' ../../apply.sh "{}" From llvm/src/tools/polly: find test/ -name *.ll | xargs ./apply.sh After that, check-all (with llvm, clang, clang-tools-extra, lld, compiler-rt, and polly all checked out). The extra 'rm' in the apply.sh script is due to a few files in clang's test suite using interesting unicode stuff that my python script was throwing exceptions on. None of those files needed to be migrated, so it seemed sufficient to ignore those cases. Reviewers: rafael, dexonsmith, grosser Differential Revision: http://reviews.llvm.org/D7636 llvm-svn: 230786
* Change the .ll syntax for comdats and add a syntactic sugar.Rafael Espindola2015-01-061-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to make comdats always explicit in the IR, we decided to make the syntax a bit more compact for the case of a GlobalObject in a comdat with the same name. Just dropping the $name causes problems for @foo = globabl i32 0, comdat $bar = comdat ... and declare void @foo() comdat $bar = comdat ... So the syntax is changed to @g1 = globabl i32 0, comdat($c1) @g2 = globabl i32 0, comdat and declare void @foo() comdat($c1) declare void @foo() comdat llvm-svn: 225302
* GlobalDCE: Don't drop any COMDAT membersDavid Majnemer2014-10-071-0/+17
| | | | | | | | | If we require a single member of a comdat, require all of the other members as well. This fixes PR20981. llvm-svn: 219191
* Remove dangling initializers in GlobalDCEBruno Cardoso Lopes2014-08-251-0/+16
| | | | | | | | | | | | | | GlobalDCE deletes global vars and updates their initializers to nullptr while leaving underlying constants to be cleaned up later by its uses. The clean up may never happen, fix this by forcing it every time it's safe to destroy constants. Final patch by Rafael Espindola http://reviews.llvm.org/D4931 <rdar://problem/17523868> llvm-svn: 216390
* Use "weak alias" instead of "alias weak"Rafael Espindola2014-07-302-4/+4
| | | | | | | | | | | | | | | | | | | | | Before this patch we had @a = weak global ... but @b = alias weak ... The patch changes aliases to look more like global variables. Looking at some really old code suggests that the reason was that the old bison based parser had a reduction for alias linkages and another one for global variable linkages. Putting the alias first avoided the reduce/reduce conflict. The days of the old .ll parser are long gone. The new one parses just "linkage" and a later check is responsible for deciding if a linkage is valid in a given context. llvm-svn: 214355
* Revert "GlobalDCE: Delete available_externally initializers if it allows ↵Pete Cooper2014-07-081-34/+1
| | | | | | | | | | removing the value the initializer is referring to." This reverts commit 5b55a47e94e28fbb56d0cd5d72c3db9105c15b4c. A test case was found to crash after this was applied. I'll file a bug to track fixing this with the test case needed. llvm-svn: 212550
* GlobalDCE: Delete available_externally initializers if it allows removing ↵Benjamin Kramer2014-07-041-1/+34
| | | | | | | | | | | | the value the initializer is referring to. This is useful for functions that are not actually available externally but referenced by a vtable of some kind. Clang emits functions like this for the MS ABI. PR20182. llvm-svn: 212337
* Allow alias to point to an arbitrary ConstantExpr.Rafael Espindola2014-06-031-4/+4
| | | | | | | | | | | | | | | | | | | | | This patch changes GlobalAlias to point to an arbitrary ConstantExpr and it is up to MC (or the system assembler) to decide if that expression is valid or not. This reduces our ability to diagnose invalid uses and how early we can spot them, but it also lets us do things like @test5 = alias inttoptr(i32 sub (i32 ptrtoint (i32* @test2 to i32), i32 ptrtoint (i32* @bar to i32)) to i32*) An important implication of this patch is that the notion of aliased global doesn't exist any more. The alias has to encode the information needed to access it in its metadata (linkage, visibility, type, etc). Another consequence to notice is that getSection has to return a "const char *". It could return a NullTerminatedStringRef if there was such a thing, but when that was proposed the decision was to just uses "const char*" for that. llvm-svn: 210062
* Fix most of PR10367.Rafael Espindola2014-05-161-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch changes the design of GlobalAlias so that it doesn't take a ConstantExpr anymore. It now points directly to a GlobalObject, but its type is independent of the aliasee type. To avoid changing all alias related tests in this patches, I kept the common syntax @foo = alias i32* @bar to mean the same as now. The cases that used to use cast now use the more general syntax @foo = alias i16, i32* @bar. Note that GlobalAlias now behaves a bit more like GlobalVariable. We know that its type is always a pointer, so we omit the '*'. For the bitcode, a nice surprise is that we were writing both identical types already, so the format change is minimal. Auto upgrade is handled by looking through the casts and no new fields are needed for now. New bitcode will simply have different types for Alias and Aliasee. One last interesting point in the patch is that replaceAllUsesWith becomes smart enough to avoid putting a ConstantExpr in the aliasee. This seems better than checking and updating every caller. A followup patch will delete getAliasedGlobal now that it is redundant. Another patch will add support for an explicit offset. llvm-svn: 209007
* Convert test to FileCheck.Rafael Espindola2014-05-131-2/+12
| | | | llvm-svn: 208644
* Teach GlobalDCE how to remove empty global_ctor entries.Nico Weber2014-05-022-0/+59
| | | | | | | | | | | | | | | | | This moves most of GlobalOpt's constructor optimization code out of GlobalOpt into Transforms/Utils/CDtorUtils.{h,cpp}. The public interface is a single function OptimizeGlobalCtorsList() that takes a predicate returning which constructors to remove. GlobalOpt calls this with a function that statically evaluates all constructors, just like it did before. This part of the change is behavior-preserving. Also add a call to this from GlobalDCE with a filter that removes global constructors that contain a "ret" instruction and nothing else – this fixes PR19590. llvm-svn: 207856
* [tests] Cleanup initialization of test suffixes.Daniel Dunbar2013-08-161-1/+0
| | | | | | | | | | | | | | | | | - Instead of setting the suffixes in a bunch of places, just set one master list in the top-level config. We now only modify the suffix list in a few suites that have one particular unique suffix (.ml, .mc, .yaml, .td, .py). - Aside from removing the need for a bunch of lit.local.cfg files, this enables 4 tests that were inadvertently being skipped (one in Transforms/BranchFolding, a .s file each in DebugInfo/AArch64 and CodeGen/PowerPC, and one in CodeGen/SI which is now failing and has been XFAILED). - This commit also fixes a bunch of config files to use config.root instead of older copy-pasted code. llvm-svn: 188513
* Revert 179826. Tests were worthless.Jakub Staszak2013-04-191-1/+1
| | | | llvm-svn: 179845
* Don't run expensive -O2 and -O3 in tests.Jakub Staszak2013-04-191-1/+1
| | | | llvm-svn: 179825
* GlobalDCE: Fix an oversight in my last commit that could lead to crashes.Benjamin Kramer2013-04-131-0/+18
| | | | | | There is a Constant with non-constant operands: blockaddress. llvm-svn: 179460
* Fix a scalability issue with complex ConstantExprs.Benjamin Kramer2013-04-131-0/+97
| | | | | | | | | | | | | | | This is basically the same fix in three different places. We use a set to avoid walking the whole tree of a big ConstantExprs multiple times. For example: (select cmp, (add big_expr 1), (add big_expr 2)) We don't want to visit big_expr twice here, it may consist of thousands of nodes. The testcase exercises this by creating an insanely large ConstantExprs out of a loop. It's questionable if the optimizer should ever create those, but this can be triggered with real C code. Fixes PR15714. llvm-svn: 179458
* Replace all instances of dg.exp file with lit.local.cfg, since all tests are ↵Eli Bendersky2012-02-162-3/+1
| | | | | | | | run with LIT now and now Dejagnu. dg.exp is no longer needed. Patch reviewed by Daniel Dunbar. It will be followed by additional cleanup patches. llvm-svn: 150664
* remove a test that is using old-style llvm.dbg intrinsics, apparently onlyChris Lattner2011-11-271-264/+0
| | | | | | fails on ppc and arm hosts. llvm-svn: 145188
* Change tests from "opt %s" to "opt < %s" so that opt doesn't see theDan Gohman2009-09-1112-13/+13
| | | | | | | | input filename so that opt doesn't print the input filename in the output so that grep lines in the tests don't unintentionally match strings in the input filename. llvm-svn: 81537
* Use opt -S instead of piping bitcode output through llvm-dis.Dan Gohman2009-09-087-8/+8
| | | | llvm-svn: 81257
* Change these tests to feed the assembly files to opt directly, insteadDan Gohman2009-09-0812-13/+13
| | | | | | of using llvm-as, now that opt supports this. llvm-svn: 81226
* While replacing an MDNode elment, properly update MDNode's operand list. Devang Patel2009-09-041-0/+264
| | | | | | MDNode's operand list does not include all elements. llvm-svn: 81045
* Add a new "available_externally" linkage type. This is intendedChris Lattner2009-04-131-0/+10
| | | | | | | | to support C99 inline, GNU extern inline, etc. Related bugzilla's include PR3517, PR3100, & PR2933. Nothing uses this yet, but it appears to work. llvm-svn: 68940
* If an alias is dead and so is its aliasee, then globaldce wouldDuncan Sands2009-02-171-0/+4
| | | | | | | crash because the alias would still be using the aliasee when the aliasee was deleted. llvm-svn: 64844
* Delete unused global aliases with internal linkage.Duncan Sands2009-01-051-0/+8
| | | | | | | | In fact this also deletes those with linkonce linkage, however this is currently dead because for the moment aliases aren't allowed to have this linkage type. llvm-svn: 61742
* sabre brings to my attention that the 'tr' suffix is also obsoleteGabor Greif2008-05-201-1/+1
| | | | llvm-svn: 51349
* Rename the last test with .llx extension to .ll, resolve duplicate test by ↵Gabor Greif2008-05-201-1/+1
| | | | | | renaming to isnan2. Now that no test has llx ending there is no need to search for them from dg.exp too. llvm-svn: 51328
* Remove llvm-upgrade and update test cases.Tanya Lattner2008-03-018-54/+51
| | | | llvm-svn: 47793
* Convert .cvsignore filesJohn Criswell2007-06-291-3/+0
| | | | llvm-svn: 37801
* For PR1336:Reid Spencer2007-04-161-1/+0
| | | | | | Un-XFAIL this since it now passes with fix to llvm-upgrade. llvm-svn: 36104
* For PR1336:Reid Spencer2007-04-151-0/+1
| | | | | | XFAIL tests covered by the PR. These will be un-XFAILed as they are fixed. llvm-svn: 36093
* For PR1319:Reid Spencer2007-04-151-2/+2
| | | | | | Upgrade to use new Tcl exec based test harness. llvm-svn: 36062
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