summaryrefslogtreecommitdiffstats
path: root/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
Commit message (Collapse)AuthorAgeFilesLines
* [InstCombine][KnownBits] Use KnownBits better to detect nsw addsCraig Topper2017-05-031-32/+44
| | | | | | | | | | | Change checkRippleForAdd from a heuristic to a full check - if it is provable that the add does not overflow return true, otherwise false. Patch by Yoav Ben-Shalom Differential Revision: https://reviews.llvm.org/D32686 llvm-svn: 302093
* [APInt] Add clearSignBit method. Use it and setSignBit in a few places. NFCICraig Topper2017-04-281-1/+1
| | | | llvm-svn: 301656
* InstCombine: Use the new SimplifyQuery versions of Simplify*. Use ↵Daniel Berlin2017-04-261-6/+4
| | | | | | AssumptionCache, DominatorTree, TargetLibraryInfo everywhere. llvm-svn: 301464
* [ValueTracking] Introduce a KnownBits struct to wrap the two APInts for ↵Craig Topper2017-04-261-26/+21
| | | | | | | | | | | | | | | | 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
* InstCombine: Fix assert when reassociating fsub with undefMatt Arsenault2017-04-241-0/+5
| | | | | | | | | | | | | There is logic to track the expected number of instructions produced. It thought in this case an instruction would be necessary to negate the result, but here it folded into a ConstantExpr fneg when the non-undef value operand was cancelled out by the second fsub. I'm not sure why we don't fold constant FP ops with undef currently, but I think that would also avoid this problem. llvm-svn: 301199
* Fix for PR32740 - Invalid floating type, unreachable between r300969 and r301029Artur Pilipenko2017-04-221-2/+5
| | | | | | The bug was introduced by r301018 "[InstCombine] fadd double (sitofp x), y check that the promotion is valid". The patch didn't expect that fadd can be on vectors not necessarily scalars. Add vector support along with the test. llvm-svn: 301070
* [InstCombine] fadd double (sitofp x), y check that the promotion is validArtur Pilipenko2017-04-211-22/+38
| | | | | | | | | | | | | | | Doing these transformations check that the result of integer addition is representable in the FP type. (fadd double (sitofp x), fpcst) --> (sitofp (add int x, intcst)) (fadd double (sitofp x), (sitofp y)) --> (sitofp (add int x, y)) This is a fix for https://bugs.llvm.org//show_bug.cgi?id=27036 Reviewed By: andrew.w.kaylor, scanon, spatel Differential Revision: https://reviews.llvm.org/D31182 llvm-svn: 301018
* [APInt] Rename getSignBit to getSignMaskCraig Topper2017-04-201-6/+6
| | | | | | | | 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 Topper2017-04-141-0/+5
| | | | | | | | | | | | 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
* Fix spelling compliment->complement. Mostly refering to 2s complement. NFCCraig Topper2017-04-111-2/+2
| | | | llvm-svn: 299970
* [InstCombine] Use commutable matchers and m_OneUse in visitSub to shorten ↵Craig Topper2017-04-101-15/+11
| | | | | | | | code. Add missing test cases. In one case I removed commute handling for a multiply with a constant since we'll eventually get the constant on the right hand side. llvm-svn: 299863
* [InstCombine] Use m_c_Add to shorten some code. Add testcases for this fold ↵Craig Topper2017-04-101-2/+1
| | | | | | since they were missing. NFC llvm-svn: 299853
* [InstCombine] Support folding of add instructions with vector constants into ↵Craig Topper2017-04-101-7/+2
| | | | | | | | | | select operations We currently only fold scalar add of constants into selects. This improves this to support vectors too. Differential Revision: https://reviews.llvm.org/D31683 llvm-svn: 299847
* [InstCombine] Use commutable and/or/xor matchers to simplify some codeCraig Topper2017-04-101-9/+4
| | | | | | | | | | | | | | | | | Summary: This is my first time using the commutable matchers so wanted to make sure I was doing it right. Are there any other matcher tricks to further shrink this? Can we commute the whole match so we don't have to LHS and RHS separately? Reviewers: davide, spatel Reviewed By: davide Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D31680 llvm-svn: 299840
* [InstCombine] Remove testing assert I accidentally left in r299710.Craig Topper2017-04-061-3/+1
| | | | llvm-svn: 299715
* [InstCombine] When checking to see if we can turn subtracts of 2^n - 1 into ↵Craig Topper2017-04-061-5/+7
| | | | | | | | xor, we only need to call computeKnownBits on the RHS not the whole subtract. While there use isMask instead of isPowerOf2(C+1) Calling computeKnownBits on the RHS should allows us to recurse one step further. isMask is equivalent to the isPowerOf2(C+1) except in the case where C is all ones. But that was already handled earlier by creating a not which is an Xor with all ones. So this should be fine. llvm-svn: 299710
* [InstCombine] rename variable for easier reading; NFCSanjay Patel2017-04-041-7/+8
| | | | | | We usually give constants a 'C' somewhere in the name... llvm-svn: 299474
* [InstCombine] Turn subtract of vectors of i1 into xor like we do for scalar ↵Craig Topper2017-04-041-1/+1
| | | | | | i1. Matches what we already do for add. llvm-svn: 299472
* [InstCombine] Fix typo last->least. NFCCraig Topper2017-03-301-3/+3
| | | | llvm-svn: 299123
* NFC. InstCombiner::visitFAdd extract LHSIntVal/RHSIntVal local variablesArtur Pilipenko2017-03-211-9/+11
| | | | llvm-svn: 298359
* [InstCombine] don't try SimplifyDemandedInstructionBits from add/sub because ↵Sanjay Patel2017-02-221-8/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | it's slow and unlikely to succeed Notably, no regression tests change when we remove these calls, and these are expensive calls. The motivation comes from the general acknowledgement that the compiler is getting slower: http://lists.llvm.org/pipermail/llvm-dev/2017-January/109188.html http://lists.llvm.org/pipermail/llvm-dev/2016-December/108279.html And specifically the test case attached to PR32037: https://bugs.llvm.org//show_bug.cgi?id=32037 Profiling the middle-end (opt) part of the compile: $ ./opt -O2 row_common.bc -o /dev/null ...visitAdd and visitSub are near the top of the instcombine list, and the calls to SimplifyDemandedInstructionBits() are high within each of those. Those calls account for 1%+ of the opt time in either debug or release profiles. And that's the rough win I see from this patch when testing opt built release from r295864 on an iMac with Haswell 4GHz (model 4790K). It seems unlikely that we'd be able to eliminate add/sub or change their operands given that add/sub normally affect all bits, and the PR32037 example shows no IR difference after this change using -O2. Also worth noting - the code comment in visitAdd: // This handles stuff like (X & 254)+1 -> (X&254)|1 ...isn't true. That transform is handled later with a call to haveNoCommonBitsSet(). Differential Revision: https://reviews.llvm.org/D30270 llvm-svn: 295898
* [InstCombine] add nsw/nuw X, signbit --> or X, signbitSanjay Patel2017-02-181-2/+9
| | | | | | | | | Changing to 'or' (rather than 'xor' when no wrapping flags are set) allows icmp simplifies to happen as expected. Differential Revision: https://reviews.llvm.org/D29729 llvm-svn: 295574
* [InstCombine] improve formatting; NFCSanjay Patel2017-02-151-6/+3
| | | | llvm-svn: 295237
* [InstCombine] add a wrapper for a common pair of transforms; NFCISanjay Patel2017-01-101-9/+3
| | | | | | | Some of the callers are artificially limiting this transform to integer types; this should make it easier to incrementally remove that restriction. llvm-svn: 291620
* [InstCombine] Combine adds across a zextDavid Majnemer2017-01-041-0/+12
| | | | | | | | | We can perform the following: (add (zext (add nuw X, C1)), C2) -> (zext (add nuw X, C1+C2)) This is only possible if C2 is negative and C2 is greater than or equal to negative C1. llvm-svn: 290927
* [InstCombine] Address post-commit feedbackDavid Majnemer2016-12-301-1/+2
| | | | llvm-svn: 290741
* [InstCombine] More thoroughly canonicalize the position of zextsDavid Majnemer2016-12-301-9/+47
| | | | | | | | We correctly canonicalized (add (sext x), (sext y)) to (sext (add x, y)) where possible. However, we didn't perform the same canonicalization for zexts or for muls. llvm-svn: 290733
* Revert @llvm.assume with operator bundles (r289755-r289757)Daniel Jasper2016-12-191-5/+5
| | | | | | | This creates non-linear behavior in the inliner (see more details in r289755's commit thread). llvm-svn: 290086
* Remove the AssumptionCacheHal Finkel2016-12-151-5/+5
| | | | | | | | | 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
* [InstCombine] use m_APInt to allow sub with constant folds for splat vectorsSanjay Patel2016-10-141-18/+19
| | | | llvm-svn: 284247
* [InstCombine] sub X, sext(bool Y) -> add X, zext(bool Y)Sanjay Patel2016-10-141-0/+11
| | | | | | | | | | | | Prefer add/zext because they are better supported in terms of value-tracking. Note that the backend should be prepared for this IR canonicalization (including vector types) after: https://reviews.llvm.org/rL284015 Differential Revision: https://reviews.llvm.org/D25135 llvm-svn: 284241
* InstCombine: Replace some never-null pointers with references. NFCJustin Bogner2016-08-051-5/+5
| | | | llvm-svn: 277792
* [InstCombine] fold add(zext(xor X, C), C) --> sext X when C is INT_MIN in ↵Sanjay Patel2016-07-191-0/+10
| | | | | | | | | | | | | | | | | | | the source type The pattern may look more obviously like a sext if written as: define i32 @g(i16 %x) { %zext = zext i16 %x to i32 %xor = xor i32 %zext, 32768 %add = add i32 %xor, -32768 ret i32 %add } We already have that fold in visitAdd(). Differential Revision: https://reviews.llvm.org/D22477 llvm-svn: 276035
* [InstCombine] allow X + signbit --> X ^ signbit for vector splatsSanjay Patel2016-07-161-3/+10
| | | | llvm-svn: 275691
* Apply clang-tidy's modernize-loop-convert to most of lib/Transforms.Benjamin Kramer2016-06-261-6/+3
| | | | | | Only minor manual fixes. No functionality change intended. llvm-svn: 273808
* Delete more dead code.Rafael Espindola2016-06-221-22/+0
| | | | | | Found by gcc 6. llvm-svn: 273402
* Remove uses of builtin comma operator.Richard Trieu2016-02-181-5/+12
| | | | | | Cleanup for upcoming Clang warning -Wcomma. No functionality change intended. llvm-svn: 261270
* Fix Clang-tidy readability-redundant-control-flow warnings; other minor fixes.Eugene Zelenko2016-02-021-2/+0
| | | | | | Differential revision: http://reviews.llvm.org/D16793 llvm-svn: 259539
* function names start with a lowercase letter; NFCSanjay Patel2016-02-011-15/+15
| | | | llvm-svn: 259425
* [InstCombine] Fix indentation. NFC.Craig Topper2015-12-211-2/+2
| | | | llvm-svn: 256131
* Fix some Clang-tidy modernize warnings, other minor fixes.Eugene Zelenko2015-11-041-14/+12
| | | | | | | | Fixed warnings are: modernize-use-override, modernize-use-nullptr and modernize-redundant-void-arg. Differential revision: http://reviews.llvm.org/D14312 llvm-svn: 252087
* don't repeat function names in comments; NFCSanjay Patel2015-09-091-1/+1
| | | | llvm-svn: 247154
* [InstCombine] Generalize sub of selects optimization to all BinaryOperatorsDavid Majnemer2015-07-141-26/+0
| | | | | | | This exposes further optimization opportunities if the selects are correlated. llvm-svn: 242235
* Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC)Alexander Kornienko2015-06-231-1/+1
| | | | | | Apparently, the style needs to be agreed upon first. llvm-svn: 240390
* [InstCombine] Optimize subtract of selects into a select of a subDavid Majnemer2015-06-231-0/+26
| | | | | | | This came up when examining some code generated by clang's IRGen for certain member pointers. llvm-svn: 240369
* Fixed/added namespace ending comments using clang-tidy. NFCAlexander Kornienko2015-06-191-1/+1
| | | | | | | | | | | | | The patch is generated using this command: tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \ -checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \ llvm/lib/ Thanks to Eugene Kosov for the original patch! llvm-svn: 240137
* [ValueTracking] refactor: extract method haveNoCommonBitsSetJingyue Wu2015-05-141-14/+2
| | | | | | | | | | | | | | | | | | | | | Summary: Extract method haveNoCommonBitsSet so that we don't have to duplicate this logic in InstCombine and SeparateConstOffsetFromGEP. This patch also makes SeparateConstOffsetFromGEP more precise by passing DominatorTree to computeKnownBits. Test Plan: value-tracking-domtree.ll that tests ValueTracking indeed leverages dominating conditions Reviewers: broune, meheff, majnemer Reviewed By: majnemer Subscribers: jholewinski, llvm-commits Differential Revision: http://reviews.llvm.org/D9734 llvm-svn: 237407
* InstCombine: Move Sub->Xor rule from SimplifyDemanded to InstCombineMatthias Braun2015-04-301-0/+13
| | | | | | | | | | The rule that turns a sub to xor if the LHS is 2^n-1 and the remaining bits are known zero, does not use the demanded bits at all: Move it to the normal InstCombine code path. Differential Revision: http://reviews.llvm.org/D9417 llvm-svn: 236268
* DataLayout is mandatory, update the API to reflect it with references.Mehdi Amini2015-03-101-44/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: Now that the DataLayout is a mandatory part of the module, let's start cleaning the codebase. This patch is a first attempt at doing that. This patch is not exactly NFC as for instance some places were passing a nullptr instead of the DataLayout, possibly just because there was a default value on the DataLayout argument to many functions in the API. Even though it is not purely NFC, there is no change in the validation. I turned as many pointer to DataLayout to references, this helped figuring out all the places where a nullptr could come up. I had initially a local version of this patch broken into over 30 independant, commits but some later commit were cleaning the API and touching part of the code modified in the previous commits, so it seemed cleaner without the intermediate state. Test Plan: Reviewers: echristo Subscribers: llvm-commits From: Mehdi Amini <mehdi.amini@apple.com> llvm-svn: 231740
* [PM] Rename InstCombine.h to InstCombineInternal.h in preparation forChandler Carruth2015-01-221-1/+1
| | | | | | | | | | | | | | | | creating a non-internal header file for the InstCombine pass. I thought about calling this InstCombiner.h or in some way more clearly associating it with the InstCombiner clas that it is primarily defining, but there are several other utility interfaces defined within this for InstCombine. If, in the course of refactoring, those end up moving elsewhere or going away, it might make more sense to make this the combiner's header alone. Naturally, this is a bikeshed to a certain degree, so feel free to lobby for a different shade of paint if this name just doesn't suit you. llvm-svn: 226783
OpenPOWER on IntegriCloud