summaryrefslogtreecommitdiffstats
path: root/llvm/lib/CodeGen/CodeGenPrepare.cpp
Commit message (Collapse)AuthorAgeFilesLines
* [Alignment][NFC] Remove dependency on GlobalObject::setAlignment(unsigned)Guillaume Chatelet2019-10-151-1/+1
| | | | | | | | | | | | | | | | | Summary: This is patch is part of a series to introduce an Alignment type. See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html See this patch for the introduction of the type: https://reviews.llvm.org/D64790 Reviewers: courbet Subscribers: arsenm, mehdi_amini, jvesely, nhaehnle, hiraditya, steven_wu, dexonsmith, dang, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D68944 llvm-svn: 374880
* Reapply r374743 with a fix for the ocaml bindingJoerg Sonnenberger2019-10-141-18/+4
| | | | | | | | | | | | | | | | | | | Add a pass to lower is.constant and objectsize intrinsics This pass lowers is.constant and objectsize intrinsics not simplified by earlier constant folding, i.e. if the object given is not constant or if not using the optimized pass chain. The result is recursively simplified and constant conditionals are pruned, so that dead blocks are removed even for -O0. This allows inline asm blocks with operand constraints to work all the time. The new pass replaces the existing lowering in the codegen-prepare pass and fallbacks in SDAG/GlobalISEL and FastISel. The latter now assert on the intrinsics. Differential Revision: https://reviews.llvm.org/D65280 llvm-svn: 374784
* Revert "Add a pass to lower is.constant and objectsize intrinsics"Dmitri Gribenko2019-10-141-4/+18
| | | | | | | This reverts commit r374743. It broke the build with Ocaml enabled: http://lab.llvm.org:8011/builders/clang-x86_64-debian-fast/builds/19218 llvm-svn: 374768
* Add a pass to lower is.constant and objectsize intrinsicsJoerg Sonnenberger2019-10-131-18/+4
| | | | | | | | | | | | | | | | | This pass lowers is.constant and objectsize intrinsics not simplified by earlier constant folding, i.e. if the object given is not constant or if not using the optimized pass chain. The result is recursively simplified and constant conditionals are pruned, so that dead blocks are removed even for -O0. This allows inline asm blocks with operand constraints to work all the time. The new pass replaces the existing lowering in the codegen-prepare pass and fallbacks in SDAG/GlobalISEL and FastISel. The latter now assert on the intrinsics. Differential Revision: https://reviews.llvm.org/D65280 llvm-svn: 374743
* CodeGenPrepare - silence static analyzer dyn_cast<> null dereference ↵Simon Pilgrim2019-10-081-11/+8
| | | | | | | | warnings. NFCI. The static analyzer is warning about potential null dereferences, but in these cases we should be able to use cast<> directly and if not assert will fire for us. llvm-svn: 374085
* [Alignment][NFC] Remove AllocaInst::setAlignment(unsigned)Guillaume Chatelet2019-09-301-1/+1
| | | | | | | | | | | | | | | | | Summary: This is patch is part of a series to introduce an Alignment type. See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html See this patch for the introduction of the type: https://reviews.llvm.org/D64790 Reviewers: courbet Subscribers: jholewinski, arsenm, jvesely, nhaehnle, eraman, hiraditya, cfe-commits, llvm-commits Tags: #clang, #llvm Differential Revision: https://reviews.llvm.org/D68141 llvm-svn: 373207
* [CodeGenPrepare] Mend "avoid crashing from replacing a phi twice" fix.Jesper Antonsson2019-09-271-1/+1
| | | | | | | | | | | | | | | | | | | Summary: An erroneously negated if-statement by an earlier (March 2019) bugfix left phi replacement/simplification under optimizeMemoryInst() in CodeGenPrepare largely inactivated. The error was found when csmith found that the same assert as in the original bug report could still be triggered in a different way. This patch fixes the bugfix. The original bug was: https://bugs.llvm.org/show_bug.cgi?id=41052 ... and the previous fix was D59358. Reviewers: aprantl, skatkov Reviewed By: skatkov Subscribers: hiraditya, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D67838 llvm-svn: 373084
* Revert [IR] allow fast-math-flags on phi of FP valuesSanjay Patel2019-09-251-1/+1
| | | | | | This reverts r372866 (git commit dec03223a97af0e4dfcb23da55c0f7f8c9b62d00) llvm-svn: 372868
* [IR] allow fast-math-flags on phi of FP valuesSanjay Patel2019-09-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The changes here are based on the corresponding diffs for allowing FMF on 'select': D61917 As discussed there, we want to have fast-math-flags be a property of an FP value because the alternative (having them on things like fcmp) leads to logical inconsistency such as: https://bugs.llvm.org/show_bug.cgi?id=38086 The earlier patch for select made almost no practical difference because most unoptimized conditional code begins life as a phi (based on what I see in clang). Similarly, I don't expect this patch to do much on its own either because SimplifyCFG promptly drops the flags when converting to select on a minimal example like: https://bugs.llvm.org/show_bug.cgi?id=39535 But once we have this plumbing in place, we should be able to wire up the FMF propagation and start solving cases like that. The change to RecurrenceDescriptor::AddReductionVar() is required to prevent a regression in a LoopVectorize test. We are intersecting the FMF of any FPMathOperator there, so if a phi is not properly annotated, new math instructions may not be either. Once we fix the propagation in SimplifyCFG, it may be safe to remove that hack. Differential Revision: https://reviews.llvm.org/D67564 llvm-svn: 372866
* [CGP] Ensure sinking multiple instructions does not invalidate dominance checksDavid Green2019-09-121-9/+23
| | | | | | | | | | | | | | | | | | In MVE, as of rL371218, we are attempting to sink chains of instructions such as: %l1 = insertelement <8 x i8> undef, i8 %l0, i32 0 %broadcast.splat26 = shufflevector <8 x i8> %l1, <8 x i8> undef, <8 x i32> zeroinitializer In certain situations though, we can end up breaking the dominance relations of instructions. This happens when we sink the instruction into a loop, but cannot remove the originals. The Use is updated, which might in fact be a Use from the second instruction to the first. This attempts to fix that by reversing the order of instruction that are sunk, and ensuring that we update the uses on new instructions if they have already been sunk, not the old ones. Differential Revision: https://reviews.llvm.org/D67366 llvm-svn: 371743
* CodeGenPrep: add separate hook say when GEPs should be used for sinking. NFCI.Tim Northover2019-09-121-2/+2
| | | | | | | | | Up to now, we've decided whether to sink address calculations using GEPs or normal arithmetic based on the useAA hook, but there are other reasons GEPs might be preferred. So this patch splits the two questions, with a default implementation falling back to useAA. llvm-svn: 371721
* Change TargetLibraryInfo analysis passes to always require FunctionTeresa Johnson2019-09-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: This is the first change to enable the TLI to be built per-function so that -fno-builtin* handling can be migrated to use function attributes. See discussion on D61634 for background. This is an enabler for fixing handling of these options for LTO, for example. This change should not affect behavior, as the provided function is not yet used to build a specifically per-function TLI, but rather enables that migration. Most of the changes were very mechanical, e.g. passing a Function to the legacy analysis pass's getTLI interface, or in Module level cases, adding a callback. This is similar to the way the per-function TTI analysis works. There was one place where we were looking for builtins but not in the context of a specific function. See FindCXAAtExit in lib/Transforms/IPO/GlobalOpt.cpp. I'm somewhat concerned my workaround could provide the wrong behavior in some corner cases. Suggestions welcome. Reviewers: chandlerc, hfinkel Subscribers: arsenm, dschuff, jvesely, nhaehnle, mehdi_amini, javed.absar, sbc100, jgravelle-google, eraman, aheejin, steven_wu, george.burgess.iv, dexonsmith, jfb, asbirlea, gchatelet, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D66428 llvm-svn: 371284
* [CGP] Remove ModifiedDT from the makeBitReverse loopCraig Topper2019-08-191-1/+0
| | | | | | | | | | I don't think anything in this loop modifies the control flow and we don't restart any iteration after setting the flag. This code was added in http://reviews.llvm.org/D16893 but looking at the test case added there the code that caused the dominator tree to change was merging blocks with their predecessor not the bitreverse optimization. Differential Revision: https://reviews.llvm.org/D66366 llvm-svn: 369283
* [CodeGenPrepare] Fix use-after-freeSanjay Patel2019-08-161-1/+2
| | | | | | | | | | | | | | | | | | | If OptimizeExtractBits() encountered a shift instruction with no operands at all, it would erase the instruction, but still return false. This previously didn’t matter because its caller would always return after processing the instruction, but https://reviews.llvm.org/D63233 changed the function’s caller to fall through if it returned false, which would then cause a use-after-free detectable by ASAN. This change makes OptimizeExtractBits return true if it removes a shift instruction with no users, terminating processing of the instruction. Patch by: @brentdax (Brent Royal-Gordon) Differential Revision: https://reviews.llvm.org/D66330 llvm-svn: 369168
* [llvm] Migrate llvm::make_unique to std::make_uniqueJonas Devlieghere2019-08-151-6/+6
| | | | | | | | Now that we've moved to C++14, we no longer need the llvm::make_unique implementation from STLExtras.h. This patch is a mechanical replacement of (hopefully) all the llvm::make_unique instances across the monorepo. llvm-svn: 369013
* [NFC][CodeGen] Modify the type element of TailCalls to simplify the ↵Kang Zhang2019-08-021-12/+9
| | | | | | | | | | | | | dupRetToEnableTailCallOpts() Summary: The old code can be simplified to define the element type of TailCalls as `BasicBlock` not `CallInst`. Also I use the for-range loop instead the for loop. Reviewed By: jsji Differential Revision: https://reviews.llvm.org/D64905 llvm-svn: 367644
* [DAGCombiner] [CodeGenPrepare] More comprehensive GEP splittingLuis Marques2019-06-171-9/+4
| | | | | | | | | | | | | | | Some GEPs were not being split, presumably because that split would just be undone by the DAGCombiner. Not performing those splits can prevent important optimizations, such as preventing the element indices / member offsets from being (partially) folded into load/store instruction immediates. This patch: - Makes the splits also occur in the cases where the base address and the GEP are in the same BB. - Ensures that the DAGCombiner doesn't reassociate them back again. Differential Revision: https://reviews.llvm.org/D60294 llvm-svn: 363544
* [CodeGenPrepare][x86] shift both sides of a vector select when profitableSanjay Patel2019-06-161-3/+42
| | | | | | | | | | | | | | | | | This is based on the example/discussion in PR37428: https://bugs.llvm.org/show_bug.cgi?id=37428 Proper vector shift instructions don't appear until AVX2, so we may generate several extra instructions within a loop trying to compensate for that. It's difficult to recover from that shift expansion later than this, so use the existing TLI hook and splat analysis to enable better codegen. This extends CGP functionality introduced with: rL201655 Differential Revision: https://reviews.llvm.org/D63233 llvm-svn: 363511
* [CodeGenPrepare] propagate debuginfo when copying a shuffleSanjay Patel2019-06-141-0/+1
| | | | llvm-svn: 363409
* TTI: Improve default costs for addrspacecastMatt Arsenault2019-06-031-2/+2
| | | | | | | | | | For some reason multiple places need to do this, and the variant the loop unroller and inliner use was not handling it. Also, introduce a new wrapper to be slightly more precise, since on AMDGPU some addrspacecasts are free, but not no-ops. llvm-svn: 362436
* Use the DataLayout::typeSizeEqualsStoreSize helper. NFCBjorn Pettersson2019-05-241-3/+2
| | | | | | | | | Just a minor refactoring to use the new helper method DataLayout::typeSizeEqualsStoreSize(). This is done when checking if getTypeSizeInBits is equal/non-equal to getTypeStoreSizeInBits. llvm-svn: 361613
* [CodeGenPrepare] Ensure we get a non-null result from getTrueOrFalseValue. NFCI.Simon Pilgrim2019-05-091-1/+3
| | | | llvm-svn: 360328
* [CodeGenPrepare] Don't split the store if it is volatileQingShan Zhang2019-05-081-0/+4
| | | | | | | | We shouldn't split the store when it is volatile. Differential Revision: https://reviews.llvm.org/D61169 llvm-svn: 360228
* [NFC] BasicBlock: refactor changePhiUses() out of replacePhiUsesWith(), use itRoman Lebedev2019-05-051-2/+1
| | | | | | | | | | | | | | | | | | | | | Summary: It is a common thing to loop over every `PHINode` in some `BasicBlock` and change old `BasicBlock` incoming block to a new `BasicBlock` incoming block. `replaceSuccessorsPhiUsesWith()` already had code to do that, it just wasn't a function. So outline it into a new function, and use it. Reviewers: chandlerc, craig.topper, spatel, danielcdh Reviewed By: craig.topper Subscribers: llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D61013 llvm-svn: 359996
* [NFC] PHINode: introduce replaceIncomingBlockWith() function, use itRoman Lebedev2019-05-051-5/+2
| | | | | | | | | | | | | | | | | | | | Summary: There is `PHINode::getBasicBlockIndex()`, `PHINode::setIncomingBlock()` and `PHINode::getNumOperands()`, but no function to replace every specified `BasicBlock*` predecessor with some other specified `BasicBlock*`. Clearly, there are a lot of places that could use that functionality. Reviewers: chandlerc, craig.topper, spatel, danielcdh Reviewed By: craig.topper Subscribers: llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D61011 llvm-svn: 359995
* [CodeGenPrepare] limit overflow intrinsic matching to a single basic block ↵Sanjay Patel2019-05-041-28/+21
| | | | | | | | | | | | | | | | | | | | | (2nd try) This is a subset of the original commit from rL359879 which was reverted because it could crash when using the 'RemovedInstructions' structure that enables delayed deletion of dead instructions. The motivating compile-time win does not require that change though. We should get most of that win from this change alone. Using/updating a dominator tree to match math overflow patterns may be very expensive in compile-time (because of the way CGP uses a DT), so just handle the single-block case. See post-commit thread for rL354298 for more details: http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20190422/646276.html Differential Revision: https://reviews.llvm.org/D61075 llvm-svn: 359969
* Revert "[CodeGenPrepare] limit overflow intrinsic matching to a single basic ↵Evgeniy Stepanov2019-05-031-42/+47
| | | | | | | | block" This reverts commit r359879, which introduced a compiler crash. llvm-svn: 359908
* [CodeGenPrepare] limit overflow intrinsic matching to a single basic blockSanjay Patel2019-05-031-47/+42
| | | | | | | | | | | | | | | | | | | Using/updating a dominator tree to match math overflow patterns may be very expensive in compile-time (because of the way CGP uses a DT), so just handle the single-block case. Also, we were restarting the iterator loops when doing the overflow intrinsic transforms by marking the dominator tree for update. That was done to prevent iterating over a removed instruction. But we can postpone the deletion using the existing "RemovedInsts" structure, and that means we don't need to update the DT. See post-commit thread for rL354298 for more details: http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20190422/646276.html Differential Revision: https://reviews.llvm.org/D61075 llvm-svn: 359879
* [CGP] Look through bitcasts when duplicating returns for tail callsFrancis Visoiu Mistrih2019-04-231-1/+3
| | | | | | | | | | | | | | | | | | | | | The simple case of: ``` int *callee(); void *caller(void *a) { if (a == NULL) return callee(); return a; } ``` would generate a regular call instead of a tail call because we don't look through the bitcast of the call to `callee` when duplicating the return blocks. Differential Revision: https://reviews.llvm.org/D60837 llvm-svn: 359041
* Include what's used in a few cpp files - these were getting transitiveEric Christopher2019-04-121-0/+1
| | | | | | includes from MCDwarf.h. llvm-svn: 358254
* [IR] Refactor attribute methods in Function class (NFC)Evandro Menezes2019-04-041-2/+2
| | | | | | | | Rename the functions that query the optimization kind attributes. Differential revision: https://reviews.llvm.org/D60287 llvm-svn: 357731
* [CGP] Reset DT when optimizing select instructionsTeresa Johnson2019-03-271-4/+8
| | | | | | | | | | | | | | | | | | | | | | | | | Summary: A recent fix (r355751) caused a compile time regression because setting the ModifiedDT flag in optimizeSelectInst means that each time a select instruction is optimized the function walk in runOnFunction stops and restarts again (which was needed to build a new DT before we started building it lazily in r356937). Now that the DT is built lazily, a simple fix is to just reset the DT at this point, rather than restarting the whole function walk. In the future other places that set ModifiedDT may want to switch to just resetting the DT directly. But that will require an evaluation to ensure that they don't otherwise need to restart the function walk. Reviewers: spatel Subscribers: jdoerfert, llvm-commits, xur Tags: #llvm Differential Revision: https://reviews.llvm.org/D59889 llvm-svn: 357111
* [CGP] Build the DominatorTree lazilyTeresa Johnson2019-03-251-34/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: In r355512 CGP was changed to build the DominatorTree only once per function traversal, to avoid repeatedly building it each time it was accessed. This solved one compile time issue but introduced another. In the second case, we now were building the DT unnecessarily many times when we performed many function traversals (i.e. more than once per function when running CGP because of changes made each time). Change to saving the DT in the CodeGenPrepare object, and building it lazily when needed. It is reset whenever we need to rebuild it. The case that exposed the issue there are 617 functions, and we walk them (i.e. execute the "while (MadeChange)" loop in runOnFunction) a total of 12083 times (so previously we were building the DT 12083 times). With this patch we only build the DT 844 times (average of 1.37 times per function). We dropped the total time to compile this file from 538.11s without this patch to 339.63s with it. There is still an issue as CGP is taking much longer than all other passes even with this patch, and before a recent compiler release cut at r355392 the total time to this compile was only 97 sec with a huge reduction in CGP time. I suspect that one of the other recent changes to CGP led to iterating each function many more times on average, but I need to do some more investigation. Reviewers: spatel Subscribers: jdoerfert, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D59696 llvm-svn: 356937
* [CGP] Make several static functions member functions (NFC)Teresa Johnson2019-03-241-19/+25
| | | | | | | This is extracted from D59696 as suggested in the review. It is preparation for making the DominatorTree a member variable. llvm-svn: 356857
* [CodeGenPrepare] limit formation of overflow intrinsics (PR41129)Sanjay Patel2019-03-211-2/+6
| | | | | | | | | | | | | | | | | | This is probably a bigger limitation than necessary, but since we don't have any evidence yet that this transform led to real-world perf improvements rather than regressions, I'm making a quick, blunt fix. In the motivating x86 example from: https://bugs.llvm.org/show_bug.cgi?id=41129 ...and shown in the regression test, we want to avoid an extra instruction in the dominating block because that could be costly. The x86 LSR test diff is reversing the changes from D57789. There's no evidence that 1 version is any better than the other yet. Differential Revision: https://reviews.llvm.org/D59602 llvm-svn: 356665
* [CGP] fix formatting; NFCSanjay Patel2019-03-201-3/+4
| | | | llvm-svn: 356572
* [CGP] convert chain of 'if' to 'switch'; NFCSanjay Patel2019-03-201-14/+13
| | | | | | | | This should be extended, but CGP does some strange things, so I'm intentionally not changing the potential order of any transforms yet. llvm-svn: 356566
* [CodeGenPrepare] avoid crashing from replacing a phi twiceMikael Holmen2019-03-151-2/+6
| | | | | | | | | | | | | | | | | | | | | | Summary: This is a fix to bug 41052: https://bugs.llvm.org/show_bug.cgi?id=41052 While trying to optimize a memory instruction in a dead basic block, we end up registering the same phi for replacement twice. This patch avoids registering more than the first replacement candidate for a phi. Patch by: JesperAntonsson Reviewers: skatkov, aprantl Reviewed By: aprantl Subscribers: jdoerfert, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D59358 llvm-svn: 356260
* [CGP] add another bailout for degenerate code (PR41064)Sanjay Patel2019-03-141-1/+5
| | | | | | | | | | | | This is almost the same as: rL355345 ...and should prevent any potential crashing from examples like: https://bugs.llvm.org/show_bug.cgi?id=41064 ...although the bug was masked by: rL355823 ...and I'm not sure how to repro the problem after that change. llvm-svn: 356218
* CodeGenPrep: preserve inbounds attribute when sinking GEPs.Tim Northover2019-03-121-3/+27
| | | | | | | | | Targets can potentially emit more efficient code if they know address computations never overflow. For example ILP32 code on AArch64 (which only has 64-bit address computation) can ignore the possibility of overflow with this extra information. llvm-svn: 355926
* [CGP] Fix UB when GEP is bound to trivial PHINodeEugene Leviant2019-03-121-0/+1
| | | | | | Differential revision: https://reviews.llvm.org/D59140 llvm-svn: 355904
* [CGP] Limit distance between overflow math and cmpSam Parker2019-03-111-0/+11
| | | | | | | | | | | | | | | Inserting an overflowing arithmetic intrinsic can increase register pressure by producing two values at a point where only one is needed, while the second use maybe several blocks away. This increase in pressure is likely to be more detrimental on performance than rematerialising one of the original instructions. So, check that the arithmetic and compare instructions are no further apart than their immediate successor/predecessor. Differential Revision: https://reviews.llvm.org/D59024 llvm-svn: 355823
* [CGP] fix comments; NFCSanjay Patel2019-03-101-2/+2
| | | | llvm-svn: 355791
* [CodeGenPrepare] Fix ModifiedDT flag in optimizeSelectInstRong Xu2019-03-081-16/+10
| | | | | | | | | | | | | | | r44412 fixed a huge compile time regression but it needed ModifiedDT flag to be maintained correctly in optimizations in optimizeBlock() and optimizeInst(). Function optimizeSelectInst() does not update the flag. This patch propagates the flag in optimizeSelectInst() back to optimizeBlock(). This patch also removes ModifiedDT in CodeGenPrepare class (which is not used). The property of ModifiedDT is now recorded in a ref parameter. Differential Revision: https://reviews.llvm.org/D59139 llvm-svn: 355751
* [CGP] Avoid repeatedly building DominatorTree causing long compile-time (NFC)Teresa Johnson2019-03-061-21/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: In r354298 a DominatorTree construction was added via new function combineToUSubWithOverflow, which was subsequently restructured into replaceMathCmpWithIntrinsic in r354689. We are hitting a very long compile time due to this repeated construction, once per math cmp in the function. We shouldn't need to build the DominatorTree more than once per function, except when a transformation invalidates it. There is already a boolean flag that is returned from these methods indicating whether the DT has been modified. We can simply build the DT once per Function walk in CodeGenPrepare::runOnFunction, since any time a change is made we break out of the Function walk and restart it. I modified the code so that both replaceMathCmpWithIntrinsic as well as mergeSExts (which was also building a DT) use the DT constructed by the run method. From -mllvm -time-passes: Before this patch: CodeGen Prepare user time is 328s With this patch: CodeGen Prepare user time is 21s Reviewers: spatel Subscribers: jdoerfert, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D58995 llvm-svn: 355512
* [CodeGenPrepare] avoid crashing on non-canonical/degenerate codeSanjay Patel2019-03-041-0/+5
| | | | | | | | | | | | The test is reduced from an example in the post-commit thread for: rL354746 http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20190304/632396.html While we must avoid dying here, the real question should be: Why is non-canonical and/or degenerate code making it to CGP when using the new pass manager? llvm-svn: 355345
* [CGP] add special-cases to form unsigned add with overflow (PR40486)Sanjay Patel2019-02-241-8/+27
| | | | | | | | | | | | | | | | | | | | There's likely a missed IR canonicalization for at least 1 of these patterns. Otherwise, we wouldn't have needed the pattern-matching enhancement in D57516. Note that -- unlike usubo added with D57789 -- the TLI hook for this transform defaults to 'on'. So if there's any perf fallout from this, targets should look at how they're lowering the uaddo node in SDAG and/or override that hook. The x86 diffs suggest that there's some missing pattern-matching for forming inc/dec. This should fix the remaining known problems in: https://bugs.llvm.org/show_bug.cgi?id=40486 https://bugs.llvm.org/show_bug.cgi?id=31754 llvm-svn: 354746
* [CGP] move overflow intrinsic insertion to common location; NFCISanjay Patel2019-02-221-17/+28
| | | | | | | | | | | We need to enhance the uaddo matching to handle special-cases as seen in PR40486 and PR31754. That means we won't necessarily have a def-use pattern, so we'll need to check dominance to determine where to place the intrinsic (as we already do for usubo). This preliminary patch is just rearranging the code, so the planned follow-up to improve uaddo will be more clear. llvm-svn: 354689
* [CGP] match a special-case of unsigned subtract overflowSanjay Patel2019-02-201-0/+5
| | | | | | | This is the 'sub0' (negate) pattern from PR31754: https://bugs.llvm.org/show_bug.cgi?id=31754 llvm-svn: 354519
* [CGP] form usub with overflow from sub+icmpSanjay Patel2019-02-181-13/+78
| | | | | | | | | | | | | | | | | The motivating x86 cases for forming the intrinsic are shown in PR31754 and PR40487: https://bugs.llvm.org/show_bug.cgi?id=31754 https://bugs.llvm.org/show_bug.cgi?id=40487 ..and those are shown in the IR test file and x86 codegen file. Matching the usubo pattern is harder than uaddo because we have 2 independent values rather than a def-use. This adds a TLI hook that should preserve the existing behavior for uaddo formation, but disables usubo formation by default. Only x86 overrides that setting for now although other targets will likely benefit by forming usbuo too. Differential Revision: https://reviews.llvm.org/D57789 llvm-svn: 354298
OpenPOWER on IntegriCloud