summaryrefslogtreecommitdiffstats
path: root/llvm/lib/Transforms
Commit message (Collapse)AuthorAgeFilesLines
* Fix for "DICompileUnit not listed in llvm.dbg.cu" verification error after ...Artur Pilipenko2019-08-282-2/+29
| | | | | | | | | | | | | | | | | | | ...cloning a function from a different module Currently when a function with debug info is cloned from a different module, the cloned function may have hanging DICompileUnits, so that the module with the cloned function fails debug info verification. The proposed fix inserts all DICompileUnits reachable from the cloned function to "llvm.dbg.cu" metadata operands of the cloned function module. Reviewed By: aprantl, efriedma Differential Revision: https://reviews.llvm.org/D66510 Patch by Oleg Pliss (Oleg.Pliss@azul.com) llvm-svn: 370265
* [ASan] Make insertion of version mismatch guard configurableJulian Lettner2019-08-281-1/+7
| | | | | | | | | | | | | | | | | | | By default ASan calls a versioned function `__asan_version_mismatch_check_vXXX` from the ASan module constructor to check that the compiler ABI version and runtime ABI version are compatible. This ensures that we get a predictable linker error instead of hard-to-debug runtime errors. Sometimes, however, we want to skip this safety guard. This new command line option allows us to do just that. rdar://47891956 Reviewed By: kubamracek Differential Revision: https://reviews.llvm.org/D66826 llvm-svn: 370258
* [InstCombine] clean up wrap propagation for reassociated ops; NFCISanjay Patel2019-08-281-11/+15
| | | | | | | | | | Always true/false checks were flagged by static analysis; https://bugs.llvm.org/show_bug.cgi?id=43143 I have not confirmed the logic difference in propagating nsw vs. nuw, but presumably we would have noticed a bug by now if that was wrong. llvm-svn: 370248
* [ValueMapper] NFC: Remove dead code to pause metadata mappingPirama Arumuga Nainar2019-08-281-17/+0
| | | | | | | | | | | | | | | | Summary: This functionality was added when Mapper::mapMetadata was recursive. It is no longer needed after r265456, which switched it to be iterative. Reviewers: dexonsmith, srhines Subscribers: hiraditya, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D66860 llvm-svn: 370236
* [Attributor] Regularly clear dependences to remove spurious onesJohannes Doerfert2019-08-281-4/+31
| | | | | | | | | | | | | | | | As dependences between abstract attributes can become stale, e.g., if one was sufficient to imply another one at some point but it has since been wakened to the point it is not usable for the formerly implied one. To weed out spurious dependences, and thereby eliminate unneeded updates, we introduce an option to determine how often the dependence cache is cleared and recomputed during the fixpoint iteration. Note that the initial value was determined such that we see a positive result on our tests. Differential Revision: https://reviews.llvm.org/D63315 llvm-svn: 370230
* Reduce scope of variable only used in a local pattern match. NFCI.Simon Pilgrim2019-08-281-1/+1
| | | | llvm-svn: 370224
* [InstCombine] Disable recursion in foldGEPICmp for vector pointer GEPsCraig Topper2019-08-281-2/+4
| | | | | | | Due to missing vector support in this function, recursion can generate worse code in some cases. llvm-svn: 370221
* Fix uninitialized variable warning in cppcheck. NFCI.Simon Pilgrim2019-08-281-1/+1
| | | | | | InstCombiner::MaxArraySizeForCombine is set outside the constructor so we need to ensure it has a default initialization value. llvm-svn: 370220
* [NFC] Added a comment to avoid possible confusionDavid Bolvansky2019-08-281-0/+2
| | | | llvm-svn: 370217
* Remove duplicate 'BitWidth' variable. NFCI.Simon Pilgrim2019-08-281-1/+0
| | | | llvm-svn: 370212
* [Attributor] Restrict liveness and return information to functionsJohannes Doerfert2019-08-281-14/+62
| | | | | | | | | | | | | | | | | | | | Summary: Until we have proper call-site information we should not recompute liveness and return information for each call site. This patch directly uses the function versions and introduces TODOs at the usage sites. The required iterations to get to the fixpoint are most of the time reduced by this change and we always avoid work duplication. Reviewers: sstefan1, uenoku Subscribers: hiraditya, bollu, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D66562 llvm-svn: 370208
* InstCombiner::visitSelectInst - rename Pred to MinMaxPred to stop shadow ↵Simon Pilgrim2019-08-281-5/+6
| | | | | | | | variable warning. NFCI. We have a lot of Predicate variables, all similarly named.... llvm-svn: 370207
* [LV] Fold tail by masking - handle reductionsAyal Zaks2019-08-283-11/+57
| | | | | | | | | | | | Allow vectorizing loops that have reductions when tail is folded by masking. A select is introduced in VPlan, choosing between the last value carried by the loop-exit/live-out instruction of the reduction, and the penultimate value carried by the reduction phi, according to the "i < n" mask of fold-tail. This select replaces the last value as the live-out value of the loop. Differential Revision: https://reviews.llvm.org/D66720 llvm-svn: 370173
* Annotate return values of allocation functions with dereferenceable_or_nullDavid Bolvansky2019-08-281-0/+33
| | | | | | | | | | | | | | | | | | | | | | | Summary: Example define dso_local noalias i8* @_Z6maixxnv() local_unnamed_addr #0 { entry: %call = tail call noalias dereferenceable_or_null(64) i8* @malloc(i64 64) #6 ret i8* %call } Reviewers: jdoerfert Reviewed By: jdoerfert Subscribers: aaron.ballman, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D66651 llvm-svn: 370168
* [LoopFusion] Fix another -Wunused-function in -DLLVM_ENABLE_ASSERTIONS=off buildFangrui Song2019-08-281-10/+10
| | | | llvm-svn: 370156
* [InstCombine] Disable some portions of foldGEPICmp for GEPs that return a ↵Craig Topper2019-08-271-11/+26
| | | | | | vector of pointers. Fix other portions. llvm-svn: 370114
* [Loads/SROA] Remove blatantly incorrect code and fix a bug revealed in the ↵Philip Reames2019-08-271-1/+1
| | | | | | | | | | | | | | | | process The code we had isSafeToLoadUnconditionally was blatantly wrong. This function takes a "Size" argument which is supposed to describe the span loaded from. Instead, the code use the size of the pointer passed (which may be unrelated!) and only checks that span. For any Size > LoadSize, this can and does lead to miscompiles. Worse, the generic code just a few lines above correctly handles the cases which *are* valid. So, let's delete said code. Removing this code revealed two issues: 1) As noted by jdoerfert the removed code incorrectly handled external globals. The test update in SROA is to stop testing incorrect behavior. 2) SROA was confusing bytes and bits, but this wasn't obvious as the Size parameter was being essentially ignored anyway. Fixed. Differential Revision: https://reviews.llvm.org/D66778 llvm-svn: 370102
* [InstCombine] Fold select with ctlz to cttzDavid Bolvansky2019-08-271-0/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: Handle pattern [0]: int ctz(unsigned int a) { int c = __clz(a & -a); return a ? 31 - c : c; } In reality, the compiler can generate much better code for cttz, so fold away this pattern. https://godbolt.org/z/c5kPtV [0] https://community.arm.com/community-help/f/discussions/2114/count-trailing-zeros Reviewers: spatel, nikic, lebedev.ri, dmgreen, hfinkel Reviewed By: hfinkel Subscribers: hfinkel, javed.absar, kristof.beyls, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D66308 llvm-svn: 370037
* [Attributor] Introduce an API to delete stuffJohannes Doerfert2019-08-271-0/+20
| | | | | | | | | | | | | | | | | Summary: During the fixpoint iteration, including the manifest stage, we should not delete stuff as other abstract attributes might have a reference to the value. Through the API this can now be done safely at the very end. Reviewers: uenoku, sstefan1 Subscribers: hiraditya, bollu, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D66779 llvm-svn: 370014
* msan, codegen, instcombine: Keep more lifetime markers used for msanVitaly Buka2019-08-261-0/+1
| | | | | | | | | | | | Reviewers: eugenis Subscribers: hiraditya, cfe-commits, #sanitizers, llvm-commits Tags: #clang, #sanitizers, #llvm Differential Revision: https://reviews.llvm.org/D66695 llvm-svn: 369979
* [hwasan] Fix test failure in r369721.Evgeniy Stepanov2019-08-261-2/+3
| | | | | | | | | Try harder to emulate "old runtime" in the test. To get the old behavior with the new runtime library, we need both disable personality function wrapping and enable landing pad instrumentation. llvm-svn: 369977
* Add a clarify comment for meaning of SafePointes [NFC]Philip Reames2019-08-261-1/+5
| | | | | | Extracted from D66688 as requested. llvm-svn: 369962
* [InstCombine] icmp eq/ne (gep inbounds P, Idx..), null -> icmp eq/ne P, null ↵Philip Reames2019-08-261-1/+6
| | | | | | | | | | for vectors Extend the transform introduced in https://reviews.llvm.org/D66608 to work for vector geps as well. Differential Revision: https://reviews.llvm.org/D66671 llvm-svn: 369949
* [Attributor] Adjust and test the iteration bound of testsJohannes Doerfert2019-08-261-1/+13
| | | | | | | | | | | | | | | | | | Summary: Try to verify how many iterations we need for a fixpoint in our tests. This patch adjust the way we count to make it easier to follow. It also adjusts the bounds to actually account for a fixpoint and not only the minimum number to pass all checks. Reviewers: uenoku, sstefan1 Subscribers: hiraditya, bollu, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D66757 llvm-svn: 369945
* [Attributor] Further cut down on non-determinismJohannes Doerfert2019-08-261-1/+1
| | | | llvm-svn: 369936
* [Attributor] Allow explicit dependence trackingJohannes Doerfert2019-08-261-14/+44
| | | | | | | | | | | | | | | By default, the Attributor tracks potential dependences between abstract attributes based on the issued Attributor::getAAFor queries. This simplifies the development of new abstract attributes but it can also lead to spurious dependences that might increase compile time and make internalization harder (D63312). With this patch, abstract attributes can opt-out of implicit dependence tracking and instead register dependences explicitly. It is up to the implementation to make sure all existing dependences are registered. Differential Revision: https://reviews.llvm.org/D63314 llvm-svn: 369935
* [LoopUnroll] Handle certain PHIs in full unrolling properlyBjorn Pettersson2019-08-261-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | Summary: When reconstructing the CFG of the loop after unrolling, LoopUnroll could in some cases remove the phi operands of loop-carried values instead of preserving them, resulting in undef phi values after loop unrolling. When doing this reconstruction, avoid removing incoming phi values for phis in the successor blocks if the successor is the block we are jumping to anyway. Patch-by: ebevhan Reviewers: fhahn, efriedma Reviewed By: fhahn Subscribers: bjope, lebedev.ri, zzheng, dmgreen, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D66334 llvm-svn: 369886
* [Constant] Add 'isElementWiseEqual()' methodRoman Lebedev2019-08-241-16/+2
| | | | | | | | | | | Promoting it from InstCombine's tryToReuseConstantFromSelectInComparison(). Return true if this constant and a constant 'Y' are element-wise equal. This is identical to just comparing the pointers, with the exception that for vectors, if only one of the constants has an `undef` element in some lane, the constants still match. llvm-svn: 369842
* [InstCombine] matchThreeWayIntCompare(): commutativity awarenessRoman Lebedev2019-08-241-13/+42
| | | | | | | | | | | | | | | | | | | | | | | | | Summary: `matchThreeWayIntCompare()` looks for ``` select i1 (a == b), i32 Equal, i32 (select i1 (a < b), i32 Less, i32 Greater) ``` but both of these selects/compares can be in it's commuted form, so out of 8 variants, only the two most basic ones is handled. This fixes regression being introduced in D66232. Reviewers: spatel, nikic, efriedma, xbolva00 Reviewed By: spatel Subscribers: hiraditya, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D66607 llvm-svn: 369841
* [InstCombine] Try to reuse constant from select in leading comparisonRoman Lebedev2019-08-242-12/+112
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: If we have e.g.: ``` %t = icmp ult i32 %x, 65536 %r = select i1 %t, i32 %y, i32 65535 ``` the constants `65535` and `65536` are suspiciously close. We could perform a transformation to deduplicate them: ``` Name: ult %t = icmp ult i32 %x, 65536 %r = select i1 %t, i32 %y, i32 65535 => %t.inv = icmp ugt i32 %x, 65535 %r = select i1 %t.inv, i32 65535, i32 %y ``` https://rise4fun.com/Alive/avb While this may seem esoteric, this should certainly be good for vectors (less constant pool usage) and for opt-for-size - need to have only one constant. But the real fun part here is that it allows further transformation, in particular it finishes cleaning up the `clamp` folding, see e.g. `canonicalize-clamp-with-select-of-constant-threshold-pattern.ll`. We start with e.g. ``` %dont_need_to_clamp_positive = icmp sle i32 %X, 32767 %dont_need_to_clamp_negative = icmp sge i32 %X, -32768 %clamp_limit = select i1 %dont_need_to_clamp_positive, i32 -32768, i32 32767 %dont_need_to_clamp = and i1 %dont_need_to_clamp_positive, %dont_need_to_clamp_negative %R = select i1 %dont_need_to_clamp, i32 %X, i32 %clamp_limit ``` without this patch we currently produce ``` %1 = icmp slt i32 %X, 32768 %2 = icmp sgt i32 %X, -32768 %3 = select i1 %2, i32 %X, i32 -32768 %R = select i1 %1, i32 %3, i32 32767 ``` which isn't really a `clamp` - both comparisons are performed on the original value, this patch changes it into ``` %1.inv = icmp sgt i32 %X, 32767 %2 = icmp sgt i32 %X, -32768 %3 = select i1 %2, i32 %X, i32 -32768 %R = select i1 %1.inv, i32 32767, i32 %3 ``` and then the magic happens! Some further transform finishes polishing it and we finally get: ``` %t1 = icmp sgt i32 %X, -32768 %t2 = select i1 %t1, i32 %X, i32 -32768 %t3 = icmp slt i32 %t2, 32767 %R = select i1 %t3, i32 %t2, i32 32767 ``` which is beautiful and just what we want. Proofs for `getFlippedStrictnessPredicateAndConstant()` for de-canonicalization: https://rise4fun.com/Alive/THl Proofs for the fold itself: https://rise4fun.com/Alive/THl Reviewers: spatel, dmgreen, nikic, xbolva00 Reviewed By: spatel Subscribers: hiraditya, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D66232 llvm-svn: 369840
* [LoopFusion] Fix -Wunused-function in -DLLVM_ENABLE_ASSERTIONS=off buildFangrui Song2019-08-241-4/+4
| | | | llvm-svn: 369836
* hwasan: Fix use of uninitialized memory.Peter Collingbourne2019-08-231-11/+12
| | | | | | | Reported by e.g. http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux/builds/23071/steps/build%20with%20ninja/logs/stdio llvm-svn: 369815
* [Attributor] Manifest alignment in load and store instructionsJohannes Doerfert2019-08-231-0/+50
| | | | | | | | | | | | | | | | Summary: We can now manifest alignment information in load/store instructions if the pointer is known to have a better alignment. Reviewers: uenoku, sstefan1, lebedev.ri Subscribers: hiraditya, bollu, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D66567 llvm-svn: 369804
* Do a sweep of symbol internalization. NFC.Benjamin Kramer2019-08-231-2/+2
| | | | llvm-svn: 369803
* Fix a bug in just submitted rL369789Philip Reames2019-08-231-1/+4
| | | | | | | | Started implementing the vector case and realized the scalar case hadn't handled the GEP producing a different type than the base correctly. It's entertaining seeing what slips through review when we're focused on the 'hard' parts. :( Also adding an extra vector test as it happened to be in workspace and wasn't worth separating. llvm-svn: 369795
* [InstCombine] icmp eq/ne (gep inbounds P, Idx..), null -> icmp eq/ne P, nullPhilip Reames2019-08-231-0/+21
| | | | | | | | | | This generalizes the isGEPKnownNonNull rule from ValueTracking to apply when we do not know if the base is non-null, and thus need to replace one condition with another. The core notion is that since an inbounds GEP can only form null if the base pointer is null and the offset is zero. However, if the offset is non-zero, the the "inbounds" marker makes the result poison. Thus, we're free to ignore the case where the offset is non-zero. Similarly, there's no case under which a non-null base can result in a null result without generating poison. Differential Revision: https://reviews.llvm.org/D66608 llvm-svn: 369789
* [Attributor] Manifest constant return valuesJohannes Doerfert2019-08-231-1/+25
| | | | | | | | | | | | | | | | Summary: If the unique return value is a constant we now replace call uses with that constant. Reviewers: sstefan1, uenoku Subscribers: hiraditya, bollu, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D66551 llvm-svn: 369785
* [Attributor] Deal with shrinking dereferenceability in a loopJohannes Doerfert2019-08-231-6/+17
| | | | | | | | | | | | | | | | | | Summary: If we have a loop in which the dereferenceability of a pointer decreases we did slowly decrease it iteration by iteration, leading to a timeout. With this patch we detect such circular reasoning and indicate a fixpoint early. Reviewers: uenoku, sstefan1 Subscribers: hiraditya, bollu, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D66558 llvm-svn: 369784
* [SLP] use range-for loops, fix formatting; NFCSanjay Patel2019-08-231-32/+32
| | | | | | | These are part of D57059, but that patch doesn't apply cleanly to trunk at this point, so we might as well remove some of the noise. llvm-svn: 369776
* [Reassoc] Small fix to support unary FNeg in NegateValue(...)Cameron McInally2019-08-231-1/+1
| | | | | | Differential Revision: https://reviews.llvm.org/D66612 llvm-svn: 369772
* [Attributor][Fix] Deal with "growing" dereferenceabilityJohannes Doerfert2019-08-231-0/+6
| | | | | | | | | | | | | | | | | | Summary: If we have a negative inbounds offset dereferenceabily "grows". However, until we do not handle the overflow that can occur in the dereferenceable bytes and the problem with loops, we simply do not grow the state. Reviewers: sstefan1, uenoku Subscribers: hiraditya, bollu, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D66557 llvm-svn: 369771
* [Attributor][NFCI] Avoid lookups when resolving returned valuesJohannes Doerfert2019-08-231-3/+16
| | | | | | | | | | If the number of potentially returned values not change since the last traversal we do not need to visit the returned values again. This works as we only add values to the returned values set now. Differential Revision: https://reviews.llvm.org/D66484 llvm-svn: 369770
* [SLP] fix formatting; NFCSanjay Patel2019-08-231-4/+3
| | | | | | | These are part of D57059, but that patch doesn't apply cleanly to trunk at this point, so we might as well remove some of the noise. llvm-svn: 369769
* [Attributor] FIX: Treat new attributes as changed onesJohannes Doerfert2019-08-231-5/+5
| | | | | | | | | | | | | | | | | | | | | Summary: When we have new attributes and we end the fixpoint iteration because the iteration limit is reached, we need to treat the new ones as if they changed in the last iteration, as they might have. This adds a test for which we should not derive anything regardless of the iteration limit, e.g., if we abort there should not be any attributes manifested in the IR. Reviewers: uenoku, sstefan1 Subscribers: hiraditya, bollu, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D66549 llvm-svn: 369768
* [Attributor][NFCI] Try to avoid potential non-deterministic behaviorJohannes Doerfert2019-08-231-12/+10
| | | | | | | This commit replaces sets with set vectors in an effort to make the behavior of the Attributor deterministic. llvm-svn: 369767
* [ThinLTO] Fix handling of weak interposable symbolsTeresa Johnson2019-08-231-22/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: Keep aliasees alive if their alias is live, otherwise we end up with an alias to a declaration, which is invalid. This can happen when the aliasee is weak and non-prevailing. This fix exposed the fact that we were then attempting to internalize the weak symbol, which was not exported as it was not prevailing. We should not internalize interposable symbols in general, unless this is the prevailing copy, since it can lead to incorrect inlining and other optimizations. Most of the changes in this patch are due to the restructuring required to pass down the prevailing callback. Finally, while implementing the test cases, I found that in the case of a weak aliasee that is still marked not live because its alias isn't live, after dropping the definition we incorrectly marked the declaration with weak linkage when resolving prevailing symbols in the module. This was due to some special case handling for symbols marked WeakLinkage in the summary located before instead of after a subsequent check for the symbol being a declaration. It turns out that we don't actually need this special case handling any more (looking back at the history, when that was added the code was structured quite differently) - we will correctly mark with weak linkage further below when the definition hasn't been dropped. Fixes PR42542. Reviewers: pcc Subscribers: mehdi_amini, inglorion, steven_wu, dexonsmith, dang, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D66264 llvm-svn: 369766
* [IndVars] Fix a bug noticed by inspectionPhilip Reames2019-08-231-1/+2
| | | | | | We were computing the loop exit value, but not ensuring the addrec belonged to the loop whose exit value we were computing. I couldn't actually trip this; the test case shows the basic setup which *might* trip this, but none of the variations I've tried actually do. llvm-svn: 369730
* [AlignmentFromAssumptions] getNewAlignmentDiff(): use getURemExpr()Fangrui Song2019-08-231-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The alignment is calculated incorrectly, thus sometimes it doesn't generate aligned mov instructions, as shown by the example below: ``` // b.cc typedef long long index; extern "C" index g_tid; extern "C" index g_num; void add3(float* __restrict__ a, float* __restrict__ b, float* __restrict__ c) { index n = 64*1024; index m = 16*1024; index k = 4*1024; index tid = g_tid; index num = g_num; __builtin_assume_aligned(a, 32); __builtin_assume_aligned(b, 32); __builtin_assume_aligned(c, 32); for (index i0=tid*k; i0<m; i0+=num*k) for (index i1=0; i1<n*m; i1+=m) for (index i2=0; i2<k; i2++) c[i1+i0+i2] = b[i0+i2] + a[i1+i0+i2]; } ``` Compile with `clang b.cc -Ofast -march=skylake -mavx2 -S` ``` vmovaps -224(%rdi,%rbx,4), %ymm0 vmovups -192(%rdi,%rbx,4), %ymm1 # should be movaps vmovups -160(%rdi,%rbx,4), %ymm2 # should be movaps vmovups -128(%rdi,%rbx,4), %ymm3 # should be movaps vaddps -224(%rsi,%rbx,4), %ymm0, %ymm0 vaddps -192(%rsi,%rbx,4), %ymm1, %ymm1 vaddps -160(%rsi,%rbx,4), %ymm2, %ymm2 vaddps -128(%rsi,%rbx,4), %ymm3, %ymm3 vmovaps %ymm0, -224(%rdx,%rbx,4) vmovups %ymm1, -192(%rdx,%rbx,4) # should be movaps vmovups %ymm2, -160(%rdx,%rbx,4) # should be movaps vmovups %ymm3, -128(%rdx,%rbx,4) # should be movaps ``` Differential Revision: https://reviews.llvm.org/D66575 Patch by Dun Liang llvm-svn: 369723
* hwasan: Untag unwound stack frames by wrapping personality functions.Peter Collingbourne2019-08-231-8/+102
| | | | | | | | | | | | | | | | | | | | | | | One problem with untagging memory in landing pads is that it only works correctly if the function that catches the exception is instrumented. If the function is uninstrumented, we have no opportunity to untag the memory. To address this, replace landing pad instrumentation with personality function wrapping. Each function with an instrumented stack has its personality function replaced with a wrapper provided by the runtime. Functions that did not have a personality function to begin with also get wrappers if they may be unwound past. As the unwinder calls personality functions during stack unwinding, the original personality function is called and the function's stack frame is untagged by the wrapper if the personality function instructs the unwinder to keep unwinding. If unwinding stops at a landing pad, the function is still responsible for untagging its stack frame if it resumes unwinding. The old landing pad mechanism is preserved for compatibility with old runtimes. Differential Revision: https://reviews.llvm.org/D66377 llvm-svn: 369721
* IR. Change strip* family of functions to not look through aliases.Peter Collingbourne2019-08-222-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | I noticed another instance of the issue where references to aliases were being replaced with aliasees, this time in InstCombine. In the instance that I saw it turned out to be only a QoI issue (a symbol ended up being missing from the symbol table due to the last reference to the alias being removed, preventing HWASAN from symbolizing a global reference), but it could easily have manifested as incorrect behaviour. Since this is the third such issue encountered (previously: D65118, D65314) it seems to be time to address this common error/QoI issue once and for all and make the strip* family of functions not look through aliases. Includes a test for the specific issue that I saw, but no doubt there are other similar bugs fixed here. As with D65118 this has been tested to make sure that the optimization isn't load bearing. I built Clang, Chromium for Linux, Android and Windows as well as the test-suite and there were no size regressions. Differential Revision: https://reviews.llvm.org/D66606 llvm-svn: 369697
OpenPOWER on IntegriCloud