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* [DAGCombiner] fold select-of-constants based on sign-bit testSanjay Patel2019-10-151-0/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | Examples: i32 X > -1 ? C1 : -1 --> (X >>s 31) | C1 i8 X < 0 ? C1 : 0 --> (X >>s 7) & C1 This is a small generalization of a fold requested in PR43650: https://bugs.llvm.org/show_bug.cgi?id=43650 The sign-bit of the condition operand can be used as a mask for the true operand: https://rise4fun.com/Alive/paT Note that we already handle some of the patterns (isNegative + scalar) because there's an over-specialized, yet over-reaching fold for that in foldSelectCCToShiftAnd(). It doesn't use any TLI hooks, so I can't easily rip out that code even though we're duplicating part of it here. This fold is guarded by TLI.convertSelectOfConstantsToMath(), so it should not cause problems for targets that prefer select over shift. Also worth noting: I thought we could generalize this further to include the case where the true operand of the select is not constant, but Alive says that may allow poison to pass through where it does not in the original select form of the code. Differential Revision: https://reviews.llvm.org/D68949 llvm-svn: 374902
* [DebugInfo] Remove some users of DBG_VALUEs IsIndirect fieldJeremy Morse2019-10-153-16/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch kills off a significant user of the "IsIndirect" field of DBG_VALUE machine insts. Brought up in in PR41675, IsIndirect is techncally redundant as it can be expressed by the DIExpression of a DBG_VALUE inst, and it isn't helpful to have two ways of expressing things. Rather than setting IsIndirect, have DBG_VALUE creators add an extra deref to the insts DIExpression. There should now be no appearences of IsIndirect=True from isel down to LiveDebugVariables / VirtRegRewriter, which is ensured by an assertion in LDVImpl::handleDebugValue. This means we also get to delete the IsIndirect handling in LiveDebugVariables. Tests can be upgraded by for example swapping the following IsIndirect=True DBG_VALUE: DBG_VALUE $somereg, 0, !123, !DIExpression(DW_OP_foo) With one where the indirection is in the DIExpression, by _appending_ a deref: DBG_VALUE $somereg, $noreg, !123, !DIExpression(DW_OP_foo, DW_OP_deref) Which both mean the same thing. Most of the test changes in this patch are updates of that form; also some changes in how the textual assembly printer handles these insts. Differential Revision: https://reviews.llvm.org/D68945 llvm-svn: 374877
* Reapply r374743 with a fix for the ocaml bindingJoerg Sonnenberger2019-10-142-39/+9
| | | | | | | | | | | | | | | | | | | 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 Gribenko2019-10-142-9/+39
| | | | | | | 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 Sonnenberger2019-10-132-39/+9
| | | | | | | | | | | | | | | | | 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
* Revert 374373: [Codegen] Alter the default promotion for saturating adds and ↵David Green2019-10-111-61/+31
| | | | | | | | | subs This commit is not extending the promoted integers as it should. Reverting whilst I look into the details. llvm-svn: 374592
* [DAGCombiner] fold vselect-of-constants to shiftSanjay Patel2019-10-111-0/+9
| | | | | | | | | | The diffs suggest that we are missing some more basic analysis/transforms, but this keeps the vector path in sync with the scalar (rL374397). This is again a preliminary step for introducing the reverse transform in IR as proposed in D63382. llvm-svn: 374555
* [DAGCombiner] fold select-of-constants to shiftSanjay Patel2019-10-101-3/+12
| | | | | | | | | | | | | | | | | | This reverses the scalar canonicalization proposed in D63382. Pre: isPowerOf2(C1) %r = select i1 %cond, i32 C1, i32 0 => %z = zext i1 %cond to i32 %r = shl i32 %z, log2(C1) https://rise4fun.com/Alive/Z50 x86 already tries to fold this pattern, but it isn't done uniformly, so we still see a diff. AArch64 probably should enable the TLI hook to benefit too, but that's a follow-on. llvm-svn: 374397
* [Codegen] Alter the default promotion for saturating adds and subsDavid Green2019-10-101-31/+61
| | | | | | | | | | | | | | | | | The default promotion for the add_sat/sub_sat nodes currently does: 1. ANY_EXTEND iN to iM 2. SHL by M-N 3. [US][ADD|SUB]SAT 4. L/ASHR by M-N If the promoted add_sat or sub_sat node is not legal, this can produce code that effectively does a lot of shifting (and requiring large constants to be materialised) just to use the overflow flag. It is simpler to just do the saturation manually, using the higher bitwidth addition and a min/max against the saturating bounds. That is what this patch attempts to do. Differential Revision: https://reviews.llvm.org/D68643 llvm-svn: 374373
* [DAGCombiner] reduce code duplication; NFCSanjay Patel2019-10-101-2/+4
| | | | llvm-svn: 374370
* [DAGCombine] Match more patterns for half word bswapAmaury Sechet2019-10-101-29/+29
| | | | | | | | | | | | | | Summary: It ensures that the bswap is generated even when a part of the subtree already matches a bswap transform. Reviewers: craig.topper, efriedma, RKSimon, lebedev.ri Subscribers: llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D68250 llvm-svn: 374340
* Conservatively add volatility and atomic checks in a few placesPhilip Reames2019-10-091-1/+9
| | | | | | | | | | | | As background, starting in D66309, I'm working on support unordered atomics analogous to volatile flags on normal LoadSDNode/StoreSDNodes for X86. As part of that, I spent some time going through usages of LoadSDNode and StoreSDNode looking for cases where we might have missed a volatility check or need an atomic check. I couldn't find any cases that clearly miscompile - i.e. no test cases - but a couple of pieces in code loop suspicious though I can't figure out how to exercise them. This patch adds defensive checks and asserts in the places my manual audit found. If anyone has any ideas on how to either a) disprove any of the checks, or b) hit the bug they might be fixing, I welcome suggestions. Differential Revision: https://reviews.llvm.org/D68419 llvm-svn: 374261
* [Support] Add mathematical constantsEvandro Menezes2019-10-091-6/+6
| | | | | | | | Add own version of the mathematical constants from the upcoming C++20 `std::numbers`. Differential revision: https://reviews.llvm.org/D68257 llvm-svn: 374207
* [FPEnv] Add constrained intrinsics for lrint and lroundKevin P. Neal2019-10-074-28/+84
| | | | | | | | | | | Earlier in the year intrinsics for lrint, llrint, lround and llround were added to llvm. The constrained versions are now implemented here. Reviewed by: andrew.w.kaylor, craig.topper, cameron.mcinally Approved by: craig.topper Differential Revision: https://reviews.llvm.org/D64746 llvm-svn: 373900
* [X86][AVX] Access a scalar float/double as a free extract from a broadcast ↵Simon Pilgrim2019-10-061-0/+5
| | | | | | | | | | | | | | | | load (PR43217) If a fp scalar is loaded and then used as both a scalar and a vector broadcast, perform the load as a broadcast and then extract the scalar for 'free' from the 0th element. This involved switching the order of the X86ISD::BROADCAST combines so we only convert to X86ISD::BROADCAST_LOAD once all other canonicalizations have been attempted. Adds a DAGCombinerInfo::recursivelyDeleteUnusedNodes wrapper. Fixes PR43217 Differential Revision: https://reviews.llvm.org/D68544 llvm-svn: 373871
* [LegalizeTypes][X86] When splitting a vselect for type legalization, don't ↵Craig Topper2019-10-061-3/+12
| | | | | | | | | | | | | | | | | | split a setcc condition if the setcc input is legal and vXi1 conditions are supported Summary: The VSELECT splitting code tries to split a setcc input as well. But on avx512 where mask registers are well supported it should be better to just split the mask and use a single compare. Reviewers: RKSimon, spatel, efriedma Reviewed By: spatel Subscribers: hiraditya, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D68359 llvm-svn: 373863
* Revert [DAGCombine] Match more patterns for half word bswapSanjay Patel2019-10-061-29/+29
| | | | | | | | This reverts r373850 (git commit 25ba49824d2d4f2347b4a7cb1623600a76ce9433) This patch appears to cause multiple codegen regression test failures - http://lab.llvm.org:8011/builders/clang-cmake-armv7-quick/builds/10680 llvm-svn: 373853
* [DAGCombine] Match more patterns for half word bswapAmaury Sechet2019-10-061-29/+29
| | | | | | | | | | | | | | Summary: It ensures that the bswap is generated even when a part of the subtree already matches a bswap transform. Reviewers: craig.topper, efriedma, RKSimon, lebedev.ri Subscribers: llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D68250 llvm-svn: 373850
* [FastISel] Copy the inline assembly dialect to the INLINEASM instruction.Craig Topper2019-10-051-0/+1
| | | | | | Fixes PR43575. llvm-svn: 373836
* Fix a *nasty* miscompile in experimental unordered atomic loweringPhilip Reames2019-10-051-3/+4
| | | | | | | | | | This is an omission in rL371441. Loads which happened to be unordered weren't being added to the PendingLoad set, and thus weren't be ordered w/respect to side effects which followed before the end of the block. Included test case is how I spotted this. We had an atomic load being folded into a using instruction after a fence that load was supposed to be ordered with. I'm sure it showed up a bunch of other ways as well. Spotted via manual inspecting of assembly differences in a corpus w/and w/o the new experimental mode. Finding this with testing would have been "unpleasant". llvm-svn: 373814
* [ScheduleDAG] When a node is cloned, add an edge between the nodes.Eli Friedman2019-10-041-0/+4
| | | | | | | | | | | | | | | InstrEmitter's virtual register handling assumes that clones are emitted after the cloned node. Make sure this assumption actually holds. Fixes a "Node emitted out of order - early" assertion on the testcase. This is probably a very rare case to actually hit in practice; even without the explicit edge, the scheduler will usually end up scheduling the nodes in the expected order due to other constraints. Differential Revision: https://reviews.llvm.org/D68068 llvm-svn: 373782
* [DAGCombiner] add operation legality checks before creating shift ops (PR43542)Sanjay Patel2019-10-031-1/+6
| | | | | | | | | | | | | | As discussed on llvm-dev and: https://bugs.llvm.org/show_bug.cgi?id=43542 ...we have transforms that assume shift operations are legal and transforms to use them are profitable, but that may not hold for simple targets. In this case, the MSP430 target custom lowers shifts by repeating (many) simpler/fixed ops. That can be avoided by keeping this code as setcc/select. Differential Revision: https://reviews.llvm.org/D68397 llvm-svn: 373666
* [LegalizeTypes] Check for already split condition before calilng ↵Craig Topper2019-10-021-4/+4
| | | | | | | | SplitVecRes_SETCC in SplitRes_SELECT. No point in manually splitting the SETCC if it was already done. llvm-svn: 373535
* Reapply r373431 "Switch lowering: omit range check for bit tests when ↵Hans Wennborg2019-10-021-18/+25
| | | | | | | | | | | | | | | | | default is unreachable (PR43129)" This was reverted in r373454 due to breaking the expensive-checks bot. This version addresses that by omitting the addSuccessorWithProb() call when omitting the range check. > Switch lowering: omit range check for bit tests when default is unreachable (PR43129) > > This is modeled after the same functionality for jump tables, which was > added in r357067. > > Differential revision: https://reviews.llvm.org/D68131 llvm-svn: 373477
* Revert r373431 "Switch lowering: omit range check for bit tests when default ↵Hans Wennborg2019-10-021-23/+17
| | | | | | | | | | | | | | | is unreachable (PR43129)" This broke http://lab.llvm.org:8011/builders/llvm-clang-x86_64-expensive-checks-win/builds/19967 > Switch lowering: omit range check for bit tests when default is unreachable (PR43129) > > This is modeled after the same functionality for jump tables, which was > added in r357067. > > Differential revision: https://reviews.llvm.org/D68131 llvm-svn: 373454
* Switch lowering: omit range check for bit tests when default is unreachable ↵Hans Wennborg2019-10-021-17/+23
| | | | | | | | | | | (PR43129) This is modeled after the same functionality for jump tables, which was added in r357067. Differential revision: https://reviews.llvm.org/D68131 llvm-svn: 373431
* [DAG][X86] Convert isNegatibleForFree/GetNegatedExpression to a target hook ↵Simon Pilgrim2019-10-012-276/+272
| | | | | | | | | | | | | | | | (PR42863) This patch converts the DAGCombine isNegatibleForFree/GetNegatedExpression into overridable TLI hooks. The intention is to let us extend existing FNEG combines to work more generally with negatible float ops, allowing it work with target specific combines and opcodes (e.g. X86's FMA variants). Unlike the SimplifyDemandedBits, we can't just handle target nodes through a Target callback, we need to do this as an override to allow targets to handle generic opcodes as well. This does mean that the target implementations has to duplicate some checks (recursion depth etc.). Partial reversion of rL372756 - I've identified the infinite loop issue inside the X86 override but haven't fixed it yet so I've only (re)committed the common TargetLowering refactoring part of the patch. Differential Revision: https://reviews.llvm.org/D67557 llvm-svn: 373343
* TLI: Remove DAG argument from getRegisterByNameMatt Arsenault2019-10-011-4/+4
| | | | | | | | | | | Replace with the MachineFunction. X86 is the only user, and only uses it for the function. This removes one obstacle from using this in GlobalISel. The other is the more tolerable EVT argument. The X86 use of the function seems questionable to me. It checks hasFP, before frame lowering. llvm-svn: 373292
* [DAGCombiner] Clang format MatchRotate. NFCAmaury Sechet2019-09-301-4/+6
| | | | llvm-svn: 373269
* [globalisel][knownbits] Allow targets to call ↵Daniel Sanders2019-09-301-2/+3
| | | | | | | | | | | | | | | | | | GISelKnownBits::computeKnownBitsImpl() Summary: It seems we missed that the target hook can't query the known-bits for the inputs to a target instruction. Fix that oversight Reviewers: aditya_nandakumar Subscribers: rovka, hiraditya, volkan, Petar.Avramovic, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D67380 llvm-svn: 373264
* [DAGCombiner] Update MatchRotate so that it returns an SDValue. NFCAmaury Sechet2019-09-301-22/+21
| | | | llvm-svn: 373260
* Support MemoryLocation::UnknownSize in TargetLowering::IntrinsicInfoTamas Berghammer2019-09-301-1/+1
| | | | | | | | | | | | | | | | Summary: Previously IntrinsicInfo::size was an unsigned what can't represent the 64 bit value used by MemoryLocation::UnknownSize. Reviewers: jmolloy Subscribers: hiraditya, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D68219 llvm-svn: 373214
* NFC changes to SelectionDAGBuilder::visitBitTestHeader(), preparing for PR43129Hans Wennborg2019-09-301-4/+4
| | | | llvm-svn: 373191
* [TargetLowering] Simplify expansion of S{ADD,SUB}ORoger Ferrer Ibanez2019-09-301-18/+13
| | | | | | | | | | ISD::SADDO uses the suggested sequence described in the section §2.4 of the RISCV Spec v2.2. ISD::SSUBO uses the dual approach but checking for (non-zero) positive. Differential Revision: https://reviews.llvm.org/D47927 llvm-svn: 373187
* [Alignment][NFC] Remove unneeded llvm:: scoping on Align typesGuillaume Chatelet2019-09-271-15/+14
| | | | llvm-svn: 373081
* [TargetLowering] Make allowsMemoryAccess methode virtual.Thomas Raoux2019-09-262-7/+7
| | | | | | | | | | | Rename old function to explicitly show that it cares only about alignment. The new allowsMemoryAccess call the function related to alignment by default and can be overridden by target to inform whether the memory access is legal or not. Differential Revision: https://reviews.llvm.org/D67121 llvm-svn: 372935
* [DAGCombiner] add one-use restriction to vector transform with cheap extractSanjay Patel2019-09-251-1/+1
| | | | | | | | | | We might be able to do better on the example in the test, but in general, we should not scalarize a splatted vector binop if there are other uses of the binop. Otherwise, we can end up with code as we had - a scalar op that is redundant with a vector op. llvm-svn: 372886
* [DAG] Pull out minimum shift value calc into a helper function. NFCI.Simon Pilgrim2019-09-251-20/+28
| | | | llvm-svn: 372856
* Revert r372333: [DAG][X86] Convert isNegatibleForFree/GetNegatedExpression ↵Ilya Biryukov2019-09-242-272/+276
| | | | | | | | | | to a target hook (PR42863) Reason: this caused severe compile time regressions in JAX. See email thread of original revision on llvm-commits for details: http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20190923/697042.html llvm-svn: 372756
* [X86][SelectionDAGBuilder] Move the hack for handling MMX shift by i32 ↵Craig Topper2019-09-231-59/+0
| | | | | | | | | | | | | | | | | | | | | | intrinsics into the X86 backend. This intrinsics should be shift by immediate, but gcc allows any i32 scalar and clang needs to match that. So we try to detect the non-constant case and move the data from an integer register to an MMX register. Previously this was done by creating a v2i32 build_vector and bitcast in SelectionDAGBuilder. This had to be done early since v2i32 isn't a legal type. The bitcast+build_vector would be DAG combined to X86ISD::MMX_MOVW2D which isel will turn into a GPR->MMX MOVD. This commit just moves the whole thing to lowering and emits the X86ISD::MMX_MOVW2D directly to avoid the illegal type. The test changes just seem to be due to nodes being linearized in a different order. llvm-svn: 372535
* [SelectionDAG] computeKnownBits/ComputeNumSignBits - cleanup ↵Simon Pilgrim2019-09-221-7/+6
| | | | | | | | demanded/unknown paths. NFCI. Merge the calls, just adjust the demandedelts if we have a valid extract_subvector constant index, else demand all elts. llvm-svn: 372521
* [SelectionDAG][Mips][Sparc] Don't allow SimplifyDemandedBits to constant ↵Craig Topper2019-09-201-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | fold TargetConstant nodes to a Constant. Summary: After the switch in SimplifyDemandedBits, it tries to create a constant when possible. If the original node is a TargetConstant the default in the switch will call computeKnownBits on the TargetConstant which will succeed. This results in the TargetConstant becoming a Constant. But TargetConstant exists to avoid being changed. I've fixed the two cases that relied on this in tree by explicitly making the nodes constant instead of target constant. The Sparc case is an old bug. The Mips case was recently introduced now that ImmArg on intrinsics gets turned into a TargetConstant when the SelectionDAG is created. I've removed the ImmArg since it lowers to generic code. Reviewers: arsenm, RKSimon, spatel Subscribers: jyknight, sdardis, wdng, arichardson, hiraditya, fedor.sergeev, jrtc27, atanasyan, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D67802 llvm-svn: 372409
* [FastISel] Fix insertion of unconditional branches during FastISelDavid Tellenbach2019-09-201-4/+4
| | | | | | | | | | | | | | | | | | | | | | The insertion of an unconditional branch during FastISel can differ depending on building with or without debug information. This happens because FastISel::fastEmitBranch emits an unconditional branch depending on the size of the current basic block without distinguishing between debug and non-debug instructions. This patch fixes this issue by ignoring debug instructions when getting the size of the basic block. Reviewers: aprantl Reviewed By: aprantl Subscribers: ormris, aprantl, hiraditya, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D67703 llvm-svn: 372389
* Reapply r372285 "GlobalISel: Don't materialize immarg arguments to intrinsics"Matt Arsenault2019-09-191-2/+16
| | | | | | | | | This reverts r372314, reapplying r372285 and the commits which depend on it (r372286-r372293, and r372296-r372297) This was missing one switch to getTargetConstant in an untested case. llvm-svn: 372338
* [DAG][X86] Convert isNegatibleForFree/GetNegatedExpression to a target hook ↵Simon Pilgrim2019-09-192-276/+272
| | | | | | | | | | | | | | | | (PR42863) This patch converts the DAGCombine isNegatibleForFree/GetNegatedExpression into overridable TLI hooks and includes a demonstration X86 implementation. The intention is to let us extend existing FNEG combines to work more generally with negatible float ops, allowing it work with target specific combines and opcodes (e.g. X86's FMA variants). Unlike the SimplifyDemandedBits, we can't just handle target nodes through a Target callback, we need to do this as an override to allow targets to handle generic opcodes as well. This does mean that the target implementations has to duplicate some checks (recursion depth etc.). I've only begun to replace X86's FNEG handling here, handling FMADDSUB/FMSUBADD negation and some low impact codegen changes (some FMA negatation propagation). We can build on this in future patches. Differential Revision: https://reviews.llvm.org/D67557 llvm-svn: 372333
* [DAGCombiner] Add node to the worklist in topological order in ↵Amaury Sechet2019-09-191-3/+3
| | | | | | | | | | | | | | | | scalarizeExtractedVectorLoad Summary: As per title. Reviewers: craig.topper, efriedma, RKSimon, lebedev.ri Subscribers: llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D66661 llvm-svn: 372327
* [DAG] Add SelectionDAG::MaxRecursionDepth constantSimon Pilgrim2019-09-193-8/+10
| | | | | | | | | | As commented on D67557 we have a lot of uses of depth checks all using magic numbers. This patch adds the SelectionDAG::MaxRecursionDepth constant and moves over some general cases to use this explicitly. Differential Revision: https://reviews.llvm.org/D67711 llvm-svn: 372315
* Revert r372285 "GlobalISel: Don't materialize immarg arguments to intrinsics"Hans Wennborg2019-09-191-16/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This broke the Chromium build, causing it to fail with e.g. fatal error: error in backend: Cannot select: t362: v4i32 = X86ISD::VSHLI t392, Constant:i8<15> See llvm-commits thread of r372285 for details. This also reverts r372286, r372287, r372288, r372289, r372290, r372291, r372292, r372293, r372296, and r372297, which seemed to depend on the main commit. > Encode them directly as an imm argument to G_INTRINSIC*. > > Since now intrinsics can now define what parameters are required to be > immediates, avoid using registers for them. Intrinsics could > potentially want a constant that isn't a legal register type. Also, > since G_CONSTANT is subject to CSE and legalization, transforms could > potentially obscure the value (and create extra work for the > selector). The register bank of a G_CONSTANT is also meaningful, so > this could throw off future folding and legalization logic for AMDGPU. > > This will be much more convenient to work with than needing to call > getConstantVRegVal and checking if it may have failed for every > constant intrinsic parameter. AMDGPU has quite a lot of intrinsics wth > immarg operands, many of which need inspection during lowering. Having > to find the value in a register is going to add a lot of boilerplate > and waste compile time. > > SelectionDAG has always provided TargetConstant for constants which > should not be legalized or materialized in a register. The distinction > between Constant and TargetConstant was somewhat fuzzy, and there was > no automatic way to force usage of TargetConstant for certain > intrinsic parameters. They were both ultimately ConstantSDNode, and it > was inconsistently used. It was quite easy to mis-select an > instruction requiring an immediate. For SelectionDAG, start emitting > TargetConstant for these arguments, and using timm to match them. > > Most of the work here is to cleanup target handling of constants. Some > targets process intrinsics through intermediate custom nodes, which > need to preserve TargetConstant usage to match the intrinsic > expectation. Pattern inputs now need to distinguish whether a constant > is merely compatible with an operand or whether it is mandatory. > > The GlobalISelEmitter needs to treat timm as a special case of a leaf > node, simlar to MachineBasicBlock operands. This should also enable > handling of patterns for some G_* instructions with immediates, like > G_FENCE or G_EXTRACT. > > This does include a workaround for a crash in GlobalISelEmitter when > ARM tries to uses "imm" in an output with a "timm" pattern source. llvm-svn: 372314
* GlobalISel: Don't materialize immarg arguments to intrinsicsMatt Arsenault2019-09-191-2/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Encode them directly as an imm argument to G_INTRINSIC*. Since now intrinsics can now define what parameters are required to be immediates, avoid using registers for them. Intrinsics could potentially want a constant that isn't a legal register type. Also, since G_CONSTANT is subject to CSE and legalization, transforms could potentially obscure the value (and create extra work for the selector). The register bank of a G_CONSTANT is also meaningful, so this could throw off future folding and legalization logic for AMDGPU. This will be much more convenient to work with than needing to call getConstantVRegVal and checking if it may have failed for every constant intrinsic parameter. AMDGPU has quite a lot of intrinsics wth immarg operands, many of which need inspection during lowering. Having to find the value in a register is going to add a lot of boilerplate and waste compile time. SelectionDAG has always provided TargetConstant for constants which should not be legalized or materialized in a register. The distinction between Constant and TargetConstant was somewhat fuzzy, and there was no automatic way to force usage of TargetConstant for certain intrinsic parameters. They were both ultimately ConstantSDNode, and it was inconsistently used. It was quite easy to mis-select an instruction requiring an immediate. For SelectionDAG, start emitting TargetConstant for these arguments, and using timm to match them. Most of the work here is to cleanup target handling of constants. Some targets process intrinsics through intermediate custom nodes, which need to preserve TargetConstant usage to match the intrinsic expectation. Pattern inputs now need to distinguish whether a constant is merely compatible with an operand or whether it is mandatory. The GlobalISelEmitter needs to treat timm as a special case of a leaf node, simlar to MachineBasicBlock operands. This should also enable handling of patterns for some G_* instructions with immediates, like G_FENCE or G_EXTRACT. This does include a workaround for a crash in GlobalISelEmitter when ARM tries to uses "imm" in an output with a "timm" pattern source. llvm-svn: 372285
* [DAGCombine][ARM][X86] (sub Carry, X) -> (addcarry (sub 0, X), 0, Carry) foldRoman Lebedev2019-09-181-0/+12
| | | | | | | | | | | | | | | | | | | Summary: `DAGCombiner::visitADDLikeCommutative()` already has a sibling fold: `(add X, Carry) -> (addcarry X, 0, Carry)` This fold, as suggested by @efriedma, helps recover from //some// of the regressions of D62266 Reviewers: efriedma, deadalnix Subscribers: javed.absar, kristof.beyls, llvm-commits, efriedma Tags: #llvm Differential Revision: https://reviews.llvm.org/D62392 llvm-svn: 372259
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