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path: root/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
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* InstCombine: Use the new SimplifyQuery versions of Simplify*. Use ↵Daniel Berlin2017-04-261-2/+1
| | | | | | AssumptionCache, DominatorTree, TargetLibraryInfo everywhere. llvm-svn: 301464
* [ValueTracking] Introduce a KnownBits struct to wrap the two APInts for ↵Craig Topper2017-04-261-4/+5
| | | | | | | | | | | | | | | | computeKnownBits This patch introduces a new KnownBits struct that wraps the two APInt used by computeKnownBits. This allows us to treat them as more of a unit. Initially I've just altered the signatures of computeKnownBits and InstCombine's simplifyDemandedBits to pass a KnownBits reference instead of two separate APInt references. I'll do similar to the SelectionDAG version of computeKnownBits/simplifyDemandedBits as a separate patch. I've added a constructor that allows initializing both APInts to the same bit width with a starting value of 0. This reduces the repeated pattern of initializing both APInts. Once place default constructed the APInts so I added a default constructor for those cases. Going forward I would like to add more methods that will work on the pairs. For example trunc, zext, and sext occur on both APInts together in several places. We should probably add a clear method that can be used to clear both pieces. Maybe a method to check for conflicting information. A method to return (Zero|One) so we don't write it out everywhere. Maybe a method for (Zero|One).isAllOnesValue() to determine if all bits are known. I'm sure there are many other methods we can come up with. Differential Revision: https://reviews.llvm.org/D32376 llvm-svn: 301432
* [APInt] Rename getSignBit to getSignMaskCraig Topper2017-04-201-1/+1
| | | | | | | | getSignBit is a static function that creates an APInt with only the sign bit set. getSignMask seems like a better name to convey its functionality. In fact several places use it and then store in an APInt named SignMask. Differential Revision: https://reviews.llvm.org/D32108 llvm-svn: 300856
* [InstCombine] Support folding a subtract with a constant LHS into a phi nodeCraig Topper2017-04-141-2/+2
| | | | | | | | | | | | We currently only support folding a subtract into a select but not a PHI. This fixes that. I had to fix an assumption in FoldOpIntoPhi that assumed the PHI node was always in operand 0. Now we pass it in like we do for FoldOpIntoSelect. But we still require some dancing to find the Constant when we create the BinOp or ConstantExpr. This is based code is similar to what we do for selects. Since I touched all call sites, this also renames FoldOpIntoPhi to foldOpIntoPhi to match coding standards. Differential Revision: https://reviews.llvm.org/D31686 llvm-svn: 300363
* [InstCombine] fix wrong undef handling when converting select to shuffleSanjay Patel2017-04-121-2/+4
| | | | | | | | | | | | | As discussed in: https://bugs.llvm.org/show_bug.cgi?id=32486 ...the canonicalization of vector select to shufflevector does not hold up when undef elements are present in the condition vector. Try to make the undef handling clear in the code and the LangRef. Differential Revision: https://reviews.llvm.org/D31980 llvm-svn: 300092
* [InstCombine] avoid breaking up bitcasted vector min/max patterns (PR32306)Sanjay Patel2017-03-161-0/+10
| | | | | | | | As the related tests show, we're not canonicalizing to this form for scalars or vectors yet, but this solves the immediate problem in: https://bugs.llvm.org/show_bug.cgi?id=32306 llvm-svn: 297989
* [InstCombine] canonicalize non-obivous forms of integer min/maxSanjay Patel2017-02-211-17/+24
| | | | | | | | | | | | | | | | This is part of trying to clean up our handling of min/max patterns in IR. By converting these to canonical form, we're more likely to recognize them because there are various places in InstCombine that don't use matchSelectPattern or m_SMax and friends. The backend fixups referenced in the now deleted TODO comment were added with: https://reviews.llvm.org/rL291392 https://reviews.llvm.org/rL289738 If there's any codegen fallout from this change, we should be able to address it in DAGCombiner or target-specific lowering. llvm-svn: 295758
* [InstCombine] Do not exercise nested max/min pattern on absAnna Thomas2017-02-211-1/+3
| | | | | | | | | | | | | | | | | | | Summary: This is a fix for assertion failure in `getInverseMinMaxSelectPattern` when ABS is passed in as a select pattern. We should not be invoking the simplification rule for ABS(MIN(~ x,y))) or ABS(MAX(~x,y)) combinations. Added a test case which would cause an assertion failure without the patch. Reviewers: sanjoy, majnemer Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D30051 llvm-svn: 295719
* Use InstCombine's builder in foldSelectCttzCtlz instead of creating a new one.Amaury Sechet2017-01-241-3/+2
| | | | | | | | | | Summary: As per title. This will add the instructiions we are interested in in the worklist. Reviewers: mehdi_amini, majnemer, andreadb Differential Revision: https://reviews.llvm.org/D29081 llvm-svn: 292957
* Fix formating in foldSelectCttzCtlz. NFCAmaury Sechet2017-01-241-1/+1
| | | | llvm-svn: 292934
* [InstCombine] if the condition of a select may be known via assumes, ↵Sanjay Patel2017-01-131-0/+14
| | | | | | | | | | | | | | | | | | | | eliminate the select This is a limited solution for PR31512: https://llvm.org/bugs/show_bug.cgi?id=31512 The motivation is that we will need to increase usage of llvm.assume and/or metadata to solve PR28430: https://llvm.org/bugs/show_bug.cgi?id=28430 ...and this kind of simplification is needed to take advantage of that extra information. The 'not' test case would be handled by: https://reviews.llvm.org/D28485 Differential Revision: https://reviews.llvm.org/D28337 llvm-svn: 291915
* Revert @llvm.assume with operator bundles (r289755-r289757)Daniel Jasper2016-12-191-1/+1
| | | | | | | This creates non-linear behavior in the inliner (see more details in r289755's commit thread). llvm-svn: 290086
* Remove the AssumptionCacheHal Finkel2016-12-151-1/+1
| | | | | | | | | After r289755, the AssumptionCache is no longer needed. Variables affected by assumptions are now found by using the new operand-bundle-based scheme. This new scheme is more computationally efficient, and also we need much less code... llvm-svn: 289756
* add optional param to copy metadata when creating selects; NFCSanjay Patel2016-11-261-7/+3
| | | | | | | | | | | There are other spots where we can use this; we're currently dropping metadata in some places, and there are proposed changes where we will want to propagate metadata. IRBuilder's CreateSelect() already has a parameter like this, so this change makes the regular 'Create' API line up with that. llvm-svn: 287976
* [InstCombine] canonicalize min/max constant to select's false valueSanjay Patel2016-11-211-0/+42
| | | | | | | | | | | | | | | | | | | | This is a first step towards canonicalization and improved folding/codegen for integer min/max as discussed here: http://lists.llvm.org/pipermail/llvm-dev/2016-November/106868.html Here, we're just matching the simplest min/max patterns and adjusting the icmp predicate while swapping the select operands. I've included FIXME tests in test/Transforms/InstCombine/select_meta.ll so it's easier to see how this might be extended (corresponds to the TODO comment in the code). That's also why I'm using matchSelectPattern() rather than a simpler check; once the backend is patched, we can just remove some of the restrictions to allow the obfuscated min/max patterns in the FIXME tests to be matched. Differential Revision: https://reviews.llvm.org/D26525 llvm-svn: 287585
* [InstCombine] use dyn_cast rather isa+cast; NFCSanjay Patel2016-11-111-2/+2
| | | | | | Follow-up to r286664 cleanup as suggested by Eli. Thanks! llvm-svn: 286671
* [InstCombine] clean up foldSelectOpOp(); NFCSanjay Patel2016-11-111-10/+4
| | | | llvm-svn: 286664
* [InstCombine] fix profitability equation for max-of-nots transformSanjay Patel2016-11-091-7/+6
| | | | | | | | | | As the test change shows, we can increase the critical path by adding a 'not' instruction, so make sure that we're actually removing an instruction if we do this transform. This transform could also cause us to miss folds of min/max pairs. llvm-svn: 286315
* [InstCombine] reduce indentation; NFCSanjay Patel2016-11-081-23/+20
| | | | llvm-svn: 286314
* [InstCombine] allow splat vector folds in adjustMinMax() (retry r285732)Sanjay Patel2016-11-071-14/+12
| | | | | | | | This was reverted at r285866 because there was a crash handling a scalar select of vectors. I added a check for that pattern and a test case based on the example provided in the post-commit thread for r285732. llvm-svn: 286113
* Revert "[InstCombine] allow splat vector folds in adjustMinMax()"Greg Bedwell2016-11-021-10/+14
| | | | | | | | | | | | | | | | | This reverts commit r285732. This change introduced a new assertion failure in the following testcase at -O2: typedef short __v8hi __attribute__((__vector_size__(16))); __v8hi foo(__v8hi &V1, __v8hi &V2, unsigned mask) { __v8hi Result = V1; if (mask & 0x80) Result[0] = V2[0]; return Result; } llvm-svn: 285866
* [InstCombine] allow splat vector folds in adjustMinMax()Sanjay Patel2016-11-011-14/+10
| | | | llvm-svn: 285732
* [InstCombine] clean up adjustMinMax(); NFCISanjay Patel2016-11-011-92/+87
| | | | | | | | | 1. Change param names for readability 2. Change pointer param to ref 3. Early exit to reduce indent 4. Change switch to if/else llvm-svn: 285718
* [InstCombine] add helper function for adjustMinMax(); NFCISanjay Patel2016-11-011-6/+19
| | | | | | This is just a cut and paste; clean-up and enhancements to follow. llvm-svn: 285715
* [InstCombine] re-use bitcasted compare operands in selects (PR28001)Sanjay Patel2016-10-291-0/+50
| | | | | | | | | | | These mixed bitcast patterns show up with SSE/AVX intrinsics because we bitcast function parameters to <2 x i64>. The bitcasts obfuscate the expected min/max forms as shown in PR28001: https://llvm.org/bugs/show_bug.cgi?id=28001#c6 Differential Revision: https://reviews.llvm.org/D25943 llvm-svn: 285495
* [InstCombine] fix foldSPFofSPF() to handle vector splatsSanjay Patel2016-10-271-22/+18
| | | | llvm-svn: 285345
* fix formatting; NFCSanjay Patel2016-10-251-13/+13
| | | | llvm-svn: 285078
* [InstCombine] fold select X, (ext X), CSanjay Patel2016-10-071-1/+21
| | | | | | | | | | | | | | | If we're going to canonicalize IR towards select of constants, try harder to create those. Also, don't lose the metadata. This is actually 4 related transforms in one patch: // select X, (sext X), C --> select X, -1, C // select X, (zext X), C --> select X, 1, C // select X, C, (sext X) --> select X, C, 0 // select X, C, (zext X) --> select X, C, 0 Differential Revision: https://reviews.llvm.org/D25126 llvm-svn: 283575
* [InstCombine] allow non-splat folds of select cond (ext X), CSanjay Patel2016-09-301-38/+33
| | | | llvm-svn: 282906
* [InstCombine] fix function names; NFCSanjay Patel2016-09-291-38/+38
| | | | | | | | Also, make foldSelectExtConst() a member of InstCombiner, remove unnecessary parameters from its interface, and group visitSelectInst helpers together in the header file. llvm-svn: 282796
* fix formatting; NFCSanjay Patel2016-09-291-11/+9
| | | | llvm-svn: 282737
* [InstCombine] canonicalize vector select with constant vector condition to ↵Sanjay Patel2016-09-161-0/+39
| | | | | | | | | | | | | | | | | | | | shuffle As discussed on llvm-dev ( http://lists.llvm.org/pipermail/llvm-dev/2016-August/104210.html ): turn a vector select with constant condition operand into a shuffle as a canonicalization step. Shuffles may be easier to reason about in conjunction with other shuffles and insert/extract. Possible known (minor?) regressions from this change are filed as: https://llvm.org/bugs/show_bug.cgi?id=28530 https://llvm.org/bugs/show_bug.cgi?id=28531 https://llvm.org/bugs/show_bug.cgi?id=30371 If something terrible happens to perf after this commit, feel free to revert until a backend fix is in place. Differential Revision: https://reviews.llvm.org/D24279 llvm-svn: 281787
* fix formatting; NFCSanjay Patel2016-09-061-19/+14
| | | | llvm-svn: 280727
* [Profile] Propagate branch metadata properly in instcombineXinliang David Li2016-08-251-11/+15
| | | | | | Differential Revision: http://reviews.llvm.org/D23590 llvm-svn: 279693
* [InstCombine] try to fold (select C, (sext A), B) into logical opsNicolai Haehnle2016-08-051-0/+56
| | | | | | | | | | | | | | | | | | | | | | Summary: Turn (select C, (sext A), B) into (sext (select C, A, B')) when A is i1 and B is a compatible constant, also for zext instead of sext. This will then be further folded into logical operations. The transformation would be valid for non-i1 types as well, but other parts of InstCombine prefer to have sext from non-i1 as an operand of select. Motivated by the shader compiler frontend in Mesa for AMDGPU, which emits i32 for boolean operations. With this change, the boolean logic is fully recovered. Reviewers: majnemer, spatel, tstellarAMD Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D22747 llvm-svn: 277801
* InstCombine: Replace some never-null pointers with references. NFCJustin Bogner2016-08-051-1/+1
| | | | llvm-svn: 277792
* [InstSimplify][InstCombine] don't crash when folding vector selects of icmpSanjay Patel2016-07-201-1/+4
| | | | | | Differential Revision: https://reviews.llvm.org/D22602 llvm-svn: 276209
* save type in local var; NFCISanjay Patel2016-07-071-10/+11
| | | | llvm-svn: 274760
* [InstCombine] enhance (select X, C1, C2 --> ext X) to handle vectorsSanjay Patel2016-07-061-22/+28
| | | | | | | | | By replacing dyn_cast of ConstantInt with m_Zero/m_One/m_AllOnes, we allow these transforms for splat vectors. Differential Revision: http://reviews.llvm.org/D21899 llvm-svn: 274696
* [InstCombine] use more specific pattern matchers; NFCISanjay Patel2016-07-061-12/+10
| | | | | | | | Follow-up from r274465: we don't need to capture the value in these cases, so just match the constant that we're looking for. m_One/m_Zero work with vector splats as well as scalars. llvm-svn: 274670
* [InstCombine] enable vector select of bools -> logic foldsSanjay Patel2016-07-031-5/+8
| | | | llvm-svn: 274465
* fix formatting; NFCSanjay Patel2016-07-031-6/+6
| | | | llvm-svn: 274463
* [InstCombine] allow more than one use for vector bitcast folding with selectsSanjay Patel2016-06-171-13/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The motivating example for this transform is similar to D20774 where bitcasts interfere with a single cmp/select sequence, but in this case we have 2 uses of each bitcast to produce min and max ops: define void @minmax_bc_store(<4 x float> %a, <4 x float> %b, <4 x float>* %ptr1, <4 x float>* %ptr2) { %cmp = fcmp olt <4 x float> %a, %b %bc1 = bitcast <4 x float> %a to <4 x i32> %bc2 = bitcast <4 x float> %b to <4 x i32> %sel1 = select <4 x i1> %cmp, <4 x i32> %bc1, <4 x i32> %bc2 %sel2 = select <4 x i1> %cmp, <4 x i32> %bc2, <4 x i32> %bc1 %bc3 = bitcast <4 x float>* %ptr1 to <4 x i32>* store <4 x i32> %sel1, <4 x i32>* %bc3 %bc4 = bitcast <4 x float>* %ptr2 to <4 x i32>* store <4 x i32> %sel2, <4 x i32>* %bc4 ret void } With this patch, we move the selects up to use the input args which allows getting rid of all of the bitcasts: define void @minmax_bc_store(<4 x float> %a, <4 x float> %b, <4 x float>* %ptr1, <4 x float>* %ptr2) { %cmp = fcmp olt <4 x float> %a, %b %sel1.v = select <4 x i1> %cmp, <4 x float> %a, <4 x float> %b %sel2.v = select <4 x i1> %cmp, <4 x float> %b, <4 x float> %a store <4 x float> %sel1.v, <4 x float>* %ptr1, align 16 store <4 x float> %sel2.v, <4 x float>* %ptr2, align 16 ret void } The asm for x86 SSE then improves from: movaps %xmm0, %xmm2 cmpltps %xmm1, %xmm2 movaps %xmm2, %xmm3 andnps %xmm1, %xmm3 movaps %xmm2, %xmm4 andnps %xmm0, %xmm4 andps %xmm2, %xmm0 orps %xmm3, %xmm0 andps %xmm1, %xmm2 orps %xmm4, %xmm2 movaps %xmm0, (%rdi) movaps %xmm2, (%rsi) To: movaps %xmm0, %xmm2 minps %xmm1, %xmm2 maxps %xmm0, %xmm1 movaps %xmm2, (%rdi) movaps %xmm1, (%rsi) The TODO comments show that we're limiting this transform only to vectors and only to bitcasts because we need to improve other transforms or risk creating worse codegen. Differential Revision: http://reviews.llvm.org/D21190 llvm-svn: 273011
* [InstCombine] move fold of select of add/sub to helper function; NFCISanjay Patel2016-06-081-61/+75
| | | | llvm-svn: 272199
* [InstCombine] fix outdated comment, simplify logic; NFCISanjay Patel2016-06-081-16/+13
| | | | llvm-svn: 272196
* [InstCombine] reduce indent; NFCSanjay Patel2016-06-081-63/+64
| | | | llvm-svn: 272193
* [InstCombine] use copyIRFlags() ; NFCISanjay Patel2016-06-081-12/+2
| | | | llvm-svn: 272191
* Avoid copies of std::strings and APInt/APFloats where we only read from itBenjamin Kramer2016-06-081-2/+2
| | | | | | | | As suggested by clang-tidy's performance-unnecessary-copy-initialization. This can easily hit lifetime issues, so I audited every change and ran the tests under asan, which came back clean. llvm-svn: 272126
* [InstCombine] Determine the result of a select based on a dominating condition.Chad Rosier2016-04-291-0/+18
| | | | | | Differential Revision: http://reviews.llvm.org/D19550 llvm-svn: 268104
* [InstCombine] Fix miscompile in FoldSPFofSPFDavid Majnemer2016-04-081-0/+3
| | | | | | | | | | | We had a select of a cast of a select but attempted to replace the outer select with the inner select dispite their incompatible types. Patch by Anton Korobeynikov! This fixes PR27236. llvm-svn: 265805
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