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* Revert r335019 "Update NRVO logic to support early return (Attempt 2)"Taiju Tsuiki2018-06-191-7/+17
| | | | llvm-svn: 335022
* Update NRVO logic to support early return (Attempt 2)Taiju Tsuiki2018-06-191-17/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: This is the second attempt of r333500 (Update NRVO logic to support early return). The previous one was reverted for a miscompilation for an incorrect NRVO set up on templates such as: ``` struct Foo {}; template <typename T> T bar() { T t; if (false) return T(); return t; } ``` Where, `t` is marked as non-NRVO variable before its instantiation. However, while its instantiation, it's left an NRVO candidate, turned into an NRVO variable later. Reviewers: rsmith Reviewed By: rsmith Subscribers: cfe-commits Differential Revision: https://reviews.llvm.org/D47586 llvm-svn: 335019
* Revert "Update NRVO logic to support early return"Sam McCall2018-05-301-7/+17
| | | | | | This reverts commit r333500, which causes stage2 compiler crashes. llvm-svn: 333547
* Update NRVO logic to support early returnTaiju Tsuiki2018-05-301-17/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: The previous implementation misses an opportunity to apply NRVO (Named Return Value Optimization) below. That discourages user to write early return code. ``` struct Foo {}; Foo f(bool b) { if (b) return Foo(); Foo oo; return oo; } ``` That is, we can/should apply RVO for a local variable if: * It's directly returned by at least one return statement. * And, all reachable return statements in its scope returns the variable directly. While, the previous implementation disables the RVO in a scope if there are multiple return statements that refers different variables. On the new algorithm, local variables are in NRVO_Candidate state at first, and a return statement changes it to NRVO_Disabled for all visible variables but the return statement refers. Then, at the end of the function AST traversal, NRVO is enabled for variables in NRVO_Candidate state and refers from at least one return statement. Reviewers: rsmith Reviewed By: rsmith Subscribers: xbolva00, Quuxplusone, arthur.j.odwyer, cfe-commits Differential Revision: https://reviews.llvm.org/D47067 llvm-svn: 333500
* Fix Scope::dump()Richard Trieu2018-01-181-64/+35
| | | | | | | | | The dump function for Scope only has 20 out of the 24 flags. Since it looped until no flags were left, having an unknown flag lead to an infinite loop. That loop has been changed to a single pass for each flag, plus an assert to alert if new flags are added. llvm-svn: 322813
* [Parser] Clear the TemplateParamScope bit of the current scope's flagAkira Hatanaka2016-04-291-1/+5
| | | | | | | | | | | | | | | | | | | | | | | if we are parsing a template specialization. This commit makes changes to clear the TemplateParamScope bit and set the TemplateParamParent field of the current scope to null if a template specialization is being parsed. Before this commit, Sema::ActOnStartOfLambdaDefinition would check whether the parent template scope had any decls to determine whether or not a template specialization was being parsed. This wasn't correct since it couldn't distinguish between a real template specialization and a template defintion with an unnamed template parameter (only template parameters with names are added to the scope's decl list). To fix the bug, this commit changes the code to check the pointer to the parent template scope rather than the decl list. rdar://problem/23440346 Differential Revision: http://reviews.llvm.org/D19175 llvm-svn: 267975
* Annotate dump() methods with LLVM_DUMP_METHOD, addressing Richard Smith ↵Yaron Keren2016-01-291-1/+1
| | | | | | r259192 post commit comment. llvm-svn: 259232
* MS ABI: Implement the MSVC 2015 scheme for scope disambiguationDavid Majnemer2015-03-191-8/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | consider C++ that looks like: inline int &f(bool b) { if (b) { static int i; return i; } static int i; return i; } Both 'i' variables must have distinct (and stable) names for linkage purposes. The MSVC 2013 ABI would number the variables using a count of the number of scopes that have been created. However, the final 'i' returns to a scope that has already been created leading to a mangling collision. MSVC 2015 fixes this by giving the second 'i' the name it would have if it were declared before the 'if'. However, this results in ABI breakage because the mangled name, in cases where there was no ambiguity, would now be different. We implement the new behavior and only enable it if we are targeting the MSVC 2015 ABI, otherwise the old behavior will be used. This fixes PR18131. llvm-svn: 232766
* Initial support for Win64 SEH IR emissionReid Kleckner2015-01-221-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The lowering looks a lot like normal EH lowering, with the exception that the exceptions are caught by executing filter expression code instead of matching typeinfo globals. The filter expressions are outlined into functions which are used in landingpad clauses where typeinfo would normally go. Major aspects that still need work: - Non-call exceptions in __try bodies won't work yet. The plan is to outline the __try block in the frontend to keep things simple. - Filter expressions cannot use local variables until capturing is implemented. - __finally blocks will not run after exceptions. Fixing this requires work in the LLVM SEH preparation pass. The IR lowering looks like this: // C code: bool safe_div(int n, int d, int *r) { __try { *r = normal_div(n, d); } __except(_exception_code() == EXCEPTION_INT_DIVIDE_BY_ZERO) { return false; } return true; } ; LLVM IR: define i32 @filter(i8* %e, i8* %fp) { %ehptrs = bitcast i8* %e to i32** %ehrec = load i32** %ehptrs %code = load i32* %ehrec %matches = icmp eq i32 %code, i32 u0xC0000094 %matches.i32 = zext i1 %matches to i32 ret i32 %matches.i32 } define i1 zeroext @safe_div(i32 %n, i32 %d, i32* %r) { %rr = invoke i32 @normal_div(i32 %n, i32 %d) to label %normal unwind to label %lpad normal: store i32 %rr, i32* %r ret i1 1 lpad: %ehvals = landingpad {i8*, i32} personality i32 (...)* @__C_specific_handler catch i8* bitcast (i32 (i8*, i8*)* @filter to i8*) %ehptr = extractvalue {i8*, i32} %ehvals, i32 0 %sel = extractvalue {i8*, i32} %ehvals, i32 1 %filter_sel = call i32 @llvm.eh.seh.typeid.for(i8* bitcast (i32 (i8*, i8*)* @filter to i8*)) %matches = icmp eq i32 %sel, %filter_sel br i1 %matches, label %eh.except, label %eh.resume eh.except: ret i1 false eh.resume: resume } Reviewers: rjmccall, rsmith, majnemer Differential Revision: http://reviews.llvm.org/D5607 llvm-svn: 226760
* Revert r213437Warren Hunt2014-07-251-8/+1
| | | | | | | We no longer plan to use __except_hander3 and rather use custom personality functions per __try block. llvm-svn: 213971
* [MS-ABI] Assign SEH handler indices to __try blocksWarren Hunt2014-07-191-1/+8
| | | | | | | | | Assigns indices to try blocks. These indices will used in constructing tables that the mscrt function __except_handler3 reads during SEH. Testing will occur once we actually emit the tables, in a subsequent patch. llvm-svn: 213437
* Sema: Check that __leave is contained in a __try block.Nico Weber2014-07-061-0/+3
| | | | | | | | | Give scope a SEHTryScope bit, set that in ParseSEHTry(), and let Sema walk the scope chain to find the SEHTry parent on __leave statements. (They are rare enough that it seems better to do the walk instead of giving Scope a SEHTryParent pointer -- this is similar to AtCatchScope.) llvm-svn: 212422
* MS static locals mangling: don't count enum scopesHans Wennborg2014-06-171-0/+3
| | | | | | | | | | We may not have the mangling for static locals vs. enums completely figured out, but at least for my simple test cases, enums should not increment the mangling number. Differential Revision: http://reviews.llvm.org/D4164 llvm-svn: 211078
* [OPENMP] Loop canonical form analysis (Sema)Alexander Musman2014-06-031-0/+10
| | | | | | | | | This patch implements semantic analysis to make sure that the loop is in OpenMP canonical form. This is the form required for 'omp simd', 'omp for' and other loop pragmas. Differential revision: http://reviews.llvm.org/D3778 llvm-svn: 210095
* [C++11] Use 'nullptr'. Sema edition.Craig Topper2014-05-261-4/+4
| | | | llvm-svn: 209613
* Rewrite NRVO determination. Track NRVO candidates on the parser Scope and ↵Nick Lewycky2014-05-031-0/+22
| | | | | | | | apply the NRVO candidate flag to all possible NRVO candidates here, and remove the flags in computeNRVO or upon template instantiation. A variable now has NRVO applied if and only if every return statement in that scope returns that variable. This is nearly optimal. Performs NRVO roughly 7% more often in a bootstrap build of clang. Patch co-authored by Richard Smith. llvm-svn: 207890
* [-cxx-abi microsoft] Implement local manglings accuratelyDavid Majnemer2014-03-051-1/+94
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: The MSVC ABI appears to mangle the lexical scope into the names of statics. Specifically, a counter is incremented whenever a scope is entered where things can be declared in such a way that an ambiguity can arise. For example, a class scope inside of a class scope doesn't do anything interesting because the nested class cannot collide with another nested class. There are problems with this scheme: - It is unreliable. The counter is only incremented when a previously never encountered scope is entered. There are cases where this will cause ambiguity amongst declarations that have the same name where one was introduced in a deep scope while the other was introduced right after in the previous lexical scope. - It is wasteful. Statements like: {{{{{{{ static int foo = a; }}}}}}} will make the mangling of "foo" larger than it need be because the scope counter has been incremented many times. Because of these problems, and practical implementation concerns. We choose not to implement this scheme if the local static or local type isn't visible. The mangling of these declarations will look very similar but the numbering will make far more sense, this scheme is lifted from the Itanium ABI implementation. Reviewers: rsmith, doug.gregor, rnk, eli.friedman, cdavis5x Reviewed By: rnk CC: cfe-commits Differential Revision: http://llvm-reviews.chandlerc.com/D2953 llvm-svn: 202951
* Fix to PR8880 (clang dies processing a for loop)Serge Pavlov2014-01-231-0/+15
| | | | | | | | | | | | | | | | | | | | | | | Due to statement expressions supported as GCC extension, it is possible to put 'break' or 'continue' into a loop/switch statement but outside its body, for example: for ( ; ({ if (first) { first = 0; continue; } 0; }); ) This code is rejected by GCC if compiled in C mode but is accepted in C++ code. GCC bug 44715 tracks this discrepancy. Clang used code generation that differs from GCC in both modes: only statement of the third expression of 'for' behaves as if it was inside loop body. This change makes code generation more close to GCC, considering 'break' or 'continue' statement in condition and increment expressions of a loop as it was inside the loop body. It also adds error for the cases when 'break'/'continue' appear outside loop due to this syntax. If code generation differ from GCC, warning is issued. Differential Revision: http://llvm-reviews.chandlerc.com/D2518 llvm-svn: 199897
* Revert r193073 and the attempt to fix it in r193170.Chandler Carruth2013-10-221-37/+0
| | | | | | | | | | This patch wasn't reviewed, and isn't correctly preserving the behaviors relied upon by QT. I don't have a direct example of fallout, but it should go through the standard code review process. For example, it should never have removed the QT test case that was added when fixing those users. llvm-svn: 193174
* Fix to PR8880 (clang dies processing a for loop).Serge Pavlov2013-10-211-0/+37
| | | | | | | | | | | | | | | | Due to statement expressions supported as GCC extension, it is possible to put 'break' or 'continue' into a loop/switch statement but outside its body, for example: for ( ; ({ if (first) { first = 0; continue; } 0; }); ) Such usage must be diagnosed as an error, GCC rejects it. To recognize this and similar patterns the flags BreakScope and ContinueScope are temporarily turned off while parsing condition expression. Differential Revision: http://llvm-reviews.chandlerc.com/D1762 llvm-svn: 193073
* Reapply r151638 and r151641.James Molloy2012-02-291-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The bug that was caught by Apple's internal buildbots was valid and also showed another bug in my implementation. These are now fixed, with regression tests added to catch them both (not Darwin-specific). Original log: ==================== Revert r151638 because it causes assertion hit on PCH creation for Cocoa.h Original log: --------------------- Correctly track tags and enum members defined in the prototype of a function, and ensure they are properly scoped. This fixes code such as: enum e {x, y}; int f(enum {y, x} n) { return 0; } This finally fixes PR5464 and PR5477. --------------------- I also reverted r151641 which was enhancement on top of r151638. ==================== llvm-svn: 151712
* Revert r151638 because it causes assertion hit on PCH creation for Cocoa.hArgyrios Kyrtzidis2012-02-281-10/+0
| | | | | | | | | | | | | | | | | | | | Original log: --------------------- Correctly track tags and enum members defined in the prototype of a function, and ensure they are properly scoped. This fixes code such as: enum e {x, y}; int f(enum {y, x} n) { return 0; } This finally fixes PR5464 and PR5477. --------------------- I also reverted r151641 which was enhancement on top of r151638. llvm-svn: 151667
* Correctly track tags and enum members defined in the prototype of a ↵James Molloy2012-02-281-0/+10
| | | | | | | | | | | | | | | function, and ensure they are properly scoped. This fixes code such as: enum e {x, y}; int f(enum {y, x} n) { return 0; } This finally fixes PR5464 and PR5477. llvm-svn: 151638
* Reject continue/break statements within members of local functions nested withinRichard Smith2012-02-171-7/+11
| | | | | | | | | | | | | | | loop and switch statements, by teaching Scope that a function scope never has a continue/break parent for the purposes of control flow. Remove the hack in block and lambda expressions which worked around this by pretending that such expressions were continue/break scopes. Remove Scope::ControlParent, since it's unused. In passing, teach default statements to recover properly from a missing ';', and add a fixit for same to both default and case labels (the latter already recovered correctly). llvm-svn: 150776
* Store a parameter index and function prototype depth in everyJohn McCall2011-05-011-0/+57
parameter node and use this to correctly mangle parameter references in function template signatures. A follow-up patch will improve the storage usage of these fields; here I've just done the lazy thing. llvm-svn: 130669
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