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path: root/llvm/lib/Target/Mips/MipsInstrInfo.cpp
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2025-11-10CodeGen: Keep reference to TargetRegisterInfo in TargetInstrInfo (#158224)Matt Arsenault
Both conceptually belong to the same subtarget, so it should not be necessary to pass in the context TargetRegisterInfo to any TargetInstrInfo member. Add this reference so those superfluous arguments can be removed. Most targets placed their TargetRegisterInfo as a member in TargetInstrInfo. A few had this owned by the TargetSubtargetInfo, so unify all targets to look the same.
2025-09-08CodeGen: Pass SubtargetInfo to TargetGenInstrInfo constructors (#157337)Matt Arsenault
This will make it possible for tablegen to make subtarget dependent decisions without adding new arguments to every target. --------- Co-authored-by: Sergei Barannikov <barannikov88@gmail.com>
2025-05-14[Mips] Add support of MipsInstrInfo::getNop() (#139863)yingopq
Fix compile crash when using __builtin_unreachable. Fix #134913.
2025-03-28MIPS: Implement isAsCheapAsAMove for addiu (#133273)YunQiang Su
Set `addiu` as `isAsCheapAsAMove` only when the src register or imm is zero only. If other cases are set `isAsCheapAsAMove`, MachineLICM will reject to hoist it.
2024-09-23[Mips] Fix mfhi/mflo hazard miscompilation about div and mult (#91449)yingopq
Fix issue1: In mips1-4, require a minimum of 2 instructions between a mflo/mfhi and the next mul/dmult/div/ddiv/divu/ddivu instruction. Fix issue2: In mips1-4, should not put mflo into the delay slot for the return. Fix https://github.com/llvm/llvm-project/issues/81291
2024-04-24[CodeGen] Make the parameter TRI required in some functions. (#85968)Xu Zhang
Fixes #82659 There are some functions, such as `findRegisterDefOperandIdx` and `findRegisterDefOperand`, that have too many default parameters. As a result, we have encountered some issues due to the lack of TRI parameters, as shown in issue #82411. Following @RKSimon 's suggestion, this patch refactors 9 functions, including `{reads, kills, defines, modifies}Register`, `registerDefIsDead`, and `findRegister{UseOperandIdx, UseOperand, DefOperandIdx, DefOperand}`, adjusting the order of the TRI parameter and making it required. In addition, all the places that call these functions have also been updated correctly to ensure no additional impact. After this, the caller of these functions should explicitly know whether to pass the `TargetRegisterInfo` or just a `nullptr`.
2023-01-05Move from llvm::makeArrayRef to ArrayRef deduction guides - llvm/ partserge-sans-paille
Use deduction guides instead of helper functions. The only non-automatic changes have been: 1. ArrayRef(some_uint8_pointer, 0) needs to be changed into ArrayRef(some_uint8_pointer, (size_t)0) to avoid an ambiguous call with ArrayRef((uint8_t*), (uint8_t*)) 2. CVSymbol sym(makeArrayRef(symStorage)); needed to be rewritten as CVSymbol sym{ArrayRef(symStorage)}; otherwise the compiler is confused and thinks we have a (bad) function prototype. There was a few similar situation across the codebase. 3. ADL doesn't seem to work the same for deduction-guides and functions, so at some point the llvm namespace must be explicitly stated. 4. The "reference mode" of makeArrayRef(ArrayRef<T> &) that acts as no-op is not supported (a constructor cannot achieve that). Per reviewers' comment, some useless makeArrayRef have been removed in the process. This is a follow-up to https://reviews.llvm.org/D140896 that introduced the deduction guides. Differential Revision: https://reviews.llvm.org/D140955
2022-12-04[Target] llvm::Optional => std::optionalFangrui Song
The updated functions are mostly internal with a few exceptions (virtual functions in TargetInstrInfo.h, TargetRegisterInfo.h). To minimize changes to LLVMCodeGen, GlobalISel files are skipped. https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2022-12-02[Target] Use std::nullopt instead of None (NFC)Kazu Hirata
This patch mechanically replaces None with std::nullopt where the compiler would warn if None were deprecated. The intent is to reduce the amount of manual work required in migrating from Optional to std::optional. This is part of an effort to migrate from llvm::Optional to std::optional: https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2022-10-30[Mips] Fix a warningKazu Hirata
This patch fixes: llvm/lib/Target/Mips/MipsInstrInfo.cpp:71:52: warning: enumerated and non-enumerated type in conditional expression [-Wextra]
2022-05-11[MIPS] Remove an incorrect microMIPS instruction aliasSimon Dardis
The microMIPS instruction set is compatible with the MIPS instruction set at the assembly level but not in terms of encodings. `nop` in microMIPS is a special case as it has the same encoding as `nop` for MIPS. Fix this error by reducing the usage of NOP in the MIPS backend such that only that ISA correct variants are produced. Differential Revision: https://reviews.llvm.org/D124716
2022-04-07[MIPS] Initial support for MIPS-I load delay slotsSimon Dardis
LLVM so far has only supported the MIPS-II and above architectures. MIPS-II is pretty close to MIPS-I, the major difference being that "load" instructions always take one extra instruction slot to propogate to registers. This patch adds support for MIPS-I by adding hazard handling for load delay slots, alongside MIPSR6 forbidden slots and FPU slots, inserting a NOP instruction between a load and any instruction immediately following that reads the load's destination register. I also included a simple regression test. Since no existing tests target MIPS-I, those all still pass. Issue ref: https://github.com/simias/psx-sdk-rs/issues/1 I also tested by building a simple demo app with Clang and running it in an emulator. Patch by: @impiaaa Differential Revision: https://reviews.llvm.org/D122427
2022-04-07[mips] Remove stale comment (NFC)Simon Dardis
Test commit for my current email address.
2022-03-16[NFC][CodeGen] Rename some functions in MachineInstr.h and remove duplicated ↵Shengchen Kan
comments
2021-12-07[MIPS] Add FPU Delay Slot for MIPS1/2/3Djordje Todorovic
MIPS I, II, and III have delay slots for floating point comparisons and floating point register transfers (mtc1, mfc1). Currently, these are not taken into account and thus broken code may be generated on these targets. This patch inserts nops as necessary, while attempting to leave the current instruction if it is safe to stay. The tests in this patch were updated by @sajattack Patch by @overdrivenpotato (Marko Mijalkovic <marko.mijalkovic97@gmail.com>) Differential Revision: https://reviews.llvm.org/D115127
2021-01-10[llvm] Ensure newlines at the end of files (NFC)Kazu Hirata
This patch eliminates pesky "No newline at end of file" messages from git diff.
2020-06-22[CSInfo][MIPS] Don't describe parameters loaded by sub/super reg copyDjordje Todorovic
When describing parameter value loaded by a COPY instruction, consider case where needed Reg value is a sub- or super- register of the COPY instruction's destination register. Without this patch, compile process will crash with the assertion "TargetInstrInfo::describeLoadedValue can't describe super- or sub-regs for copy instructions". Patch by Nikola Tesic Differential revision: https://reviews.llvm.org/D82000
2020-06-04[CSInfo][MIPS] Describe parameter value loaded by ADDiuDjordje Todorovic
Describe parameter's value loaded by MIPS ADDiu instruction. When parameter's value is loaded into a register by mips ADDiu/DADDiu instruction, it could be described correctly and emitted as DW_AT_GNU_call_site_value. Patch by Nikola Tesic Differential revision: https://reviews.llvm.org/D78108
2020-03-31[Alignment][NFC] Transitionning more getMachineMemOperand call sitesGuillaume Chatelet
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, dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, hiraditya, kbarton, jrtc27, atanasyan, Jim, kerbowa, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D77121
2019-11-03[mips] Split long lines in the code. NFCSimon Atanasyan
2019-09-25[TargetInstrInfo] Let findCommutedOpIndices take const MachineInstr&Simon Pilgrim
Neither the base implementation of findCommutedOpIndices nor any in-tree target modifies the instruction passed in and there is no reason why they would in the future. Committed on behalf of @hvdijk (Harald van Dijk) Differential Revision: https://reviews.llvm.org/D66138 llvm-svn: 372882
2019-02-08Implementation of asm-goto support in LLVMCraig Topper
This patch accompanies the RFC posted here: http://lists.llvm.org/pipermail/llvm-dev/2018-October/127239.html This patch adds a new CallBr IR instruction to support asm-goto inline assembly like gcc as used by the linux kernel. This instruction is both a call instruction and a terminator instruction with multiple successors. Only inline assembly usage is supported today. This also adds a new INLINEASM_BR opcode to SelectionDAG and MachineIR to represent an INLINEASM block that is also considered a terminator instruction. There will likely be more bug fixes and optimizations to follow this, but we felt it had reached a point where we would like to switch to an incremental development model. Patch by Craig Topper, Alexander Ivchenko, Mikhail Dvoretckii Differential Revision: https://reviews.llvm.org/D53765 llvm-svn: 353563
2019-01-19Update the file headers across all of the LLVM projects in the monorepoChandler Carruth
to reflect the new license. We understand that people may be surprised that we're moving the header entirely to discuss the new license. We checked this carefully with the Foundation's lawyer and we believe this is the correct approach. Essentially, all code in the project is now made available by the LLVM project under our new license, so you will see that the license headers include that license only. Some of our contributors have contributed code under our old license, and accordingly, we have retained a copy of our old license notice in the top-level files in each project and repository. llvm-svn: 351636
2019-01-17[mips] Emit .reloc R_{MICRO}MIPS_JALR along with j(al)r(c) $25Vladimir Stefanovic
The callee address is added as an optional operand (MCSymbol) in AdjustInstrPostInstrSelection() and then used by asm printer to insert: '.reloc tmplabel, R_MIPS_JALR, symbol tmplabel:'. Controlled with '-mips-jalr-reloc', default is true. Differential revision: https://reviews.llvm.org/D56694 llvm-svn: 351485
2018-08-16[MI] Change the array of `MachineMemOperand` pointers to beChandler Carruth
a generically extensible collection of extra info attached to a `MachineInstr`. The primary change here is cleaning up the APIs used for setting and manipulating the `MachineMemOperand` pointer arrays so chat we can change how they are allocated. Then we introduce an extra info object that using the trailing object pattern to attach some number of MMOs but also other extra info. The design of this is specifically so that this extra info has a fixed necessary cost (the header tracking what extra info is included) and everything else can be tail allocated. This pattern works especially well with a `BumpPtrAllocator` which we use here. I've also added the basic scaffolding for putting interesting pointers into this, namely pre- and post-instruction symbols. These aren't used anywhere yet, they're just there to ensure I've actually gotten the data structure types correct. I'll flesh out support for these in a subsequent patch (MIR dumping, parsing, the works). Finally, I've included an optimization where we store any single pointer inline in the `MachineInstr` to avoid the allocation overhead. This is expected to be the overwhelmingly most common case and so should avoid any memory usage growth due to slightly less clever / dense allocation when dealing with >1 MMO. This did require several ergonomic improvements to the `PointerSumType` to reasonably support the various usage models. This also has a side effect of freeing up 8 bits within the `MachineInstr` which could be repurposed for something else. The suggested direction here came largely from Hal Finkel. I hope it was worth it. ;] It does hopefully clear a path for subsequent extensions w/o nearly as much leg work. Lots of thanks to Reid and Justin for careful reviews and ideas about how to do all of this. Differential Revision: https://reviews.llvm.org/D50701 llvm-svn: 339940
2018-08-07[mips] Handle branch expansion corner casesAleksandar Beserminji
When potential jump instruction and target are in the same segment, use jump instruction with immediate field. In cases where offset does not fit immediate value of a bc/j instructions, offset is stored into register, and then jump register instruction is used. Differential Revision: https://reviews.llvm.org/D48019 llvm-svn: 339126
2018-05-16[mips] Add support for isBranchOffsetInRange and use it for MipsLongBranchSimon Dardis
Add support for this target hook, covering MIPS, microMIPS and MIPSR6, along with some tests. Also add missing getOppositeBranchOpc() cases exposed by the tests. Reviewers: atanasyan, abeserminji, smaksimovic Differential Revision: https://reviews.llvm.org/D46794 llvm-svn: 332446
2018-05-09[DebugInfo] Examine all uses of isDebugValue() for debug instructions.Shiva Chen
Because we create a new kind of debug instruction, DBG_LABEL, we need to check all passes which use isDebugValue() to check MachineInstr is debug instruction or not. When expelling debug instructions, we should expel both DBG_VALUE and DBG_LABEL. So, I create a new function, isDebugInstr(), in MachineInstr to check whether the MachineInstr is debug instruction or not. This patch has no new test case. I have run regression test and there is no difference in regression test. Differential Revision: https://reviews.llvm.org/D45342 Patch by Hsiangkai Wang. llvm-svn: 331844
2018-03-30Fix a bunch of typoes. NFCFangrui Song
llvm-svn: 328907
2018-02-21[mips] Spectre variant two mitigation for MIPSR2Simon Dardis
This patch provides mitigation for CVE-2017-5715, Spectre variant two, which affects the P5600 and P6600. It implements the LLVM part of -mindirect-jump=hazard. It is _not_ enabled by default for the P5600. The migitation strategy suggested by MIPS for these processors is to use hazard barrier instructions. 'jalr.hb' and 'jr.hb' are hazard barrier variants of the 'jalr' and 'jr' instructions respectively. These instructions impede the execution of instruction stream until architecturally defined hazards (changes to the instruction stream, privileged registers which may affect execution) are cleared. These instructions in MIPS' designs are not speculated past. These instructions are used with the attribute +use-indirect-jump-hazard when branching indirectly and for indirect function calls. These instructions are defined by the MIPS32R2 ISA, so this mitigation method is not compatible with processors which implement an earlier revision of the MIPS ISA. Performance benchmarking of this option with -fpic and lld using -z hazardplt shows a difference of overall 10%~ time increase for the LLVM testsuite. Certain benchmarks such as methcall show a substantially larger increase in time due to their nature. Reviewers: atanasyan, zoran.jovanovic Differential Revision: https://reviews.llvm.org/D43486 llvm-svn: 325653
2017-12-18Reland "[mips] Fix the target specific instruction verifier"Simon Dardis
Fix an off by one error in the bounds checking for 'dinsu' and update the ranges in the test comments so that they are accurate. This version has the correct commit message. Reviewers: atanasyan Differential Revision: https://reviews.llvm.org/D41183 llvm-svn: 320991
2017-12-18Revert "[mips] Fix the target specific instruction verifier"Simon Dardis
This reverts commit r320974. The commit message lacked the Differential Revison: line. llvm-svn: 320975
2017-12-18[mips] Fix the target specific instruction verifierSimon Dardis
Fix an off by one error in the bounds checking for 'dinsu' and update the ranges in the test comments so that they are accurate. Reviewers: atanasyan https://reviews.llvm.org/D41183 llvm-svn: 320974
2017-12-11[mips] Removal of microMIPS64R6Aleksandar Beserminji
All files and parts of files related to microMIPS4R6 are removed. When target is microMIPS4R6, errors are printed. This is LLVM part of patch. Differential Revision: https://reviews.llvm.org/D35625 llvm-svn: 320350
2017-12-07[CodeGen] Use MachineOperand::print in the MIRPrinter for MO_Register.Francis Visoiu Mistrih
Work towards the unification of MIR and debug output by refactoring the interfaces. For MachineOperand::print, keep a simple version that can be easily called from `dump()`, and a more complex one which will be called from both the MIRPrinter and MachineInstr::print. Add extra checks inside MachineOperand for detached operands (operands with getParent() == nullptr). https://reviews.llvm.org/D40836 * find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/kill: ([^ ]+) ([^ ]+)<def> ([^ ]+)/kill: \1 def \2 \3/g' * find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/kill: ([^ ]+) ([^ ]+) ([^ ]+)<def>/kill: \1 \2 def \3/g' * find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/kill: def ([^ ]+) ([^ ]+) ([^ ]+)<def>/kill: def \1 \2 def \3/g' * find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/<def>//g' * find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<kill>/killed \1/g' * find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<imp-use,kill>/implicit killed \1/g' * find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<dead>/dead \1/g' * find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<def[ ]*,[ ]*dead>/dead \1/g' * find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<imp-def[ ]*,[ ]*dead>/implicit-def dead \1/g' * find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<imp-def>/implicit-def \1/g' * find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<imp-use>/implicit \1/g' * find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<internal>/internal \1/g' * find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<undef>/undef \1/g' llvm-svn: 320022
2017-11-28[CodeGen] Print register names in lowercase in both MIR and debug outputFrancis Visoiu Mistrih
As part of the unification of the debug format and the MIR format, always print registers as lowercase. * Only debug printing is affected. It now follows MIR. Differential Revision: https://reviews.llvm.org/D40417 llvm-svn: 319187
2017-11-17Fix a bunch more layering of CodeGen headers that are in TargetDavid Blaikie
All these headers already depend on CodeGen headers so moving them into CodeGen fixes the layering (since CodeGen depends on Target, not the other way around). llvm-svn: 318490
2017-10-26[mips] Fix PR35071Simon Dardis
PR35071 exposed the fact that MipsInstrInfo::removeBranch did not walk past debug instructions when removing branches for the control flow optimizer, which lead to duplicated conditional branches. If the target of the branch was a removable block, only the conditional branch in the terminating position would have it's MBB operands updated, leaving the first branch with a dangling MBB operand. The MIPS long branch pass would then trigger an assertion when attempting to examine the instruction with dangling MBB operand. This resolves PR35071. Thanks to Alex Richardson for reporting the issue! Reviewers: atanasyan Differential Revision: https://reviews.llvm.org/D39288 llvm-svn: 316654
2017-10-18[mips] Fix analyzeBranch to handle debug dataSimon Dardis
In the case where there was a conditional branch followed by a unconditional branch with debug instruction separating them, MipsInstrInfo::analyzeBranch would not skip past debug instruction when searching for the second branch which give erroneous results about the control flow of the block. This could lead to the branch folder to merge the non-fall through case into it's predecessor, leaving the conditional branch with a dangling basic block operand. This resolves PR34975. Thanks to Alexander Richardson for reporting the issue! Reviewers: atanasyan Differential Revision: https://reviews.llvm.org/D39003 llvm-svn: 316084
2017-10-11[mips] Add support for parsing target specific flags for MIRSimon Dardis
Reviewers: atanasyan Differential Revision: https://reviews.llvm.org/D38620 llvm-svn: 315451
2017-09-14[mips] Pick the right variant of DINS upfront and enable target instruction ↵Simon Dardis
verification This patch complements D16810 "[mips] Make isel select the correct DEXT variant up front.". Now ISel picks the right variant of DINS, so now there is no need to replace DINS with the appropriate variant during MipsMCCodeEmitter::encodeInstruction(). This patch also enables target specific instruction verification for ins, dins, dinsm, dinsu, ext, dext, dextm, dextu. These instructions have constraints that are checked when generating MipsISD::Ins and MipsISD::Ext nodes, but these constraints are not checked during instruction selection. Adding machine verification should catch outstanding cases. Finally, correct a bug that instruction verification uncovered, where the position operand of a DINSU generated during lowering was being silently and accidently corrected to the correct value. Reviewers: slthakur Differential Revision: https://reviews.llvm.org/D34809 llvm-svn: 313254
2017-08-03[Mips] Fix some Clang-tidy modernize-use-using and Include What You Use ↵Eugene Zelenko
warnings; other minor fixes (NFC). llvm-svn: 309993
2017-06-13[MIPS] BuildCondBr should preserve MO flagsSimon Dardis
While simplifying branches in the MachineInstr representation, the routine BuildCondBr must preserve flags on register MachineOperands. In particular, it must preserve the <undef> flag. This fixes a bug that is unlikely to occur in any real scenario, but which bugpoint is likely to introduce. Patch By Nick Johnson! Reviewers: ahatanak, sdardis Differential Revision: https://reviews.llvm.org/D34041 llvm-svn: 305290
2017-03-31[mips][msa] Prevent output operand from commuting for dpadd_[su].df insPetar Jovanovic
Implementation of TargetInstrInfo::findCommutedOpIndices for MIPS target, restricting commutativity to second and third operand only for dpaadd_[su].df instructions therein. Prior to this change, there were cases where the vector that is to be added to the dot product of the other two could take a position other than the first one in the instruction, generating false output in the destination vector. Such behavior has been noticed in the two functions generating v2i64 output values so far. Other ones may exhibit such behavior as well, just not for the vector operands which are present in the test at the moment. Tests altered so that the function's first operand is a constant splat so that it can be loaded with a ldi instruction, since that is the case in which the erroneous instruction operand placement has occurred. We check that the register which is present in the ldi instruction is placed as the first operand in the corresponding dpadd instruction. Patch by Stefan Maksimovic. Differential Revision: https://reviews.llvm.org/D30827 llvm-svn: 299223
2017-01-13[CodeGen] Rename MachineInstrBuilder::addOperand. NFCDiana Picus
Rename from addOperand to just add, to match the other method that has been added to MachineInstrBuilder for adding more than just 1 operand. See https://reviews.llvm.org/D28057 for the whole discussion. Differential Revision: https://reviews.llvm.org/D28556 llvm-svn: 291891
2016-09-14Finish renaming remaining analyzeBranch functionsMatt Arsenault
llvm-svn: 281535
2016-09-14Make analyzeBranch family of instruction names consistentMatt Arsenault
analyzeBranch was renamed to use lowercase first, rename the related set to match. llvm-svn: 281506
2016-09-14AArch64: Use TTI branch functions in branch relaxationMatt Arsenault
The main change is to return the code size from InsertBranch/RemoveBranch. Patch mostly by Tim Northover llvm-svn: 281505
2016-09-11CodeGen: Give MachineBasicBlock::reverse_iterator a handle to the current MIDuncan P. N. Exon Smith
Now that MachineBasicBlock::reverse_instr_iterator knows when it's at the end (since r281168 and r281170), implement MachineBasicBlock::reverse_iterator directly on top of an ilist::reverse_iterator by adding an IsReverse template parameter to MachineInstrBundleIterator. This replaces another hard-to-reason-about use of std::reverse_iterator on list iterators, matching the changes for ilist::reverse_iterator from r280032 (see the "out of scope" section at the end of that commit message). MachineBasicBlock::reverse_iterator now has a handle to the current node and has obvious invalidation semantics. r280032 has a more detailed explanation of how list-style reverse iterators (invalidated when the pointed-at node is deleted) are different from vector-style reverse iterators like std::reverse_iterator (invalidated on every operation). A great motivating example is this commit's changes to lib/CodeGen/DeadMachineInstructionElim.cpp. Note: If your out-of-tree backend deletes instructions while iterating on a MachineBasicBlock::reverse_iterator or converts between MachineBasicBlock::iterator and MachineBasicBlock::reverse_iterator, you'll need to update your code in similar ways to r280032. The following table might help: [Old] ==> [New] delete &*RI, RE = end() delete &*RI++ RI->erase(), RE = end() RI++->erase() reverse_iterator(I) std::prev(I).getReverse() reverse_iterator(I) ++I.getReverse() --reverse_iterator(I) I.getReverse() reverse_iterator(std::next(I)) I.getReverse() RI.base() std::prev(RI).getReverse() RI.base() ++RI.getReverse() --RI.base() RI.getReverse() std::next(RI).base() RI.getReverse() (For more details, have a look at r280032.) llvm-svn: 281172
2016-08-18[mips] Correct tail call encoding for MIPSR6Simon Dardis
r277708 enabled tails calls for MIPS but used the 'jr' instruction when the jump target was held in a register. For MIPSR6, 'jalr $zero, $reg' should have been used. Additionally, add missing patterns for external and global symbols for tail calls. Reviewers: dsanders, vkalintiris Differential Review: https://reviews.llvm.org/D23301 llvm-svn: 279064