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* [RISCV] Fix evaluating %pcrel_lo against global and weak symbolsJames Clarke2020-01-231-66/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: Previously, we would erroneously turn %pcrel_lo(label), where label has a %pcrel_hi against a weak symbol, into %pcrel_lo(label + offset), as evaluatePCRelLo would believe the target independent logic was going to fold it. Moreover, even if that were fixed, shouldForceRelocation lacks an MCAsmLayout and thus cannot evaluate the %pcrel_hi fixup to a value and check the symbol, so we would then erroneously constant-fold the %pcrel_lo whilst leaving the %pcrel_hi intact. After D72197, this same sequence also occurs for symbols with global binding, which is triggered in real-world code. Instead, as discussed in D71978, we introduce a new FKF_IsTarget flag to avoid these kinds of issues. All the resolution logic happens in one place, with no coordination required between RISCAsmBackend and RISCVMCExpr to ensure they implement the same logic twice. Although the implementation of %pcrel_hi can be left as target independent, we make it target dependent to ensure that they are handled identically to %pcrel_lo, otherwise we risk one of them being constant folded but the other being preserved. This also allows us to properly support fixup pairs where the instructions are in different fragments. Reviewers: asb, lenary, efriedma Reviewed By: efriedma Subscribers: arichardson, hiraditya, rbar, johnrusso, simoncook, sabuasal, niosHD, kito-cheng, shiva0217, MaskRay, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, psnobl, benna, Jim, s.egerton, pzheng, sameer.abuasal, apazos, luismarques, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D73211 (cherry picked from commit 3f5976c97dbfefb4669abcf968bd79a9a64c18e0)
* [RISCV] Fix evalutePCRelLo for symbols at the end of a fragmentJames Clarke2020-01-081-1/+5
| | | | | | | | | | | | | | | | | | Summary: This is analogous to D58943, which correctly finds the corresponding fixup. However, when linker relaxations are disabled and we evaluate the fixup, we need to also ensure we use an offset of 0 rather than the size of the previous fragment. Reviewers: asb, efriedma, lenary Reviewed By: efriedma Subscribers: hiraditya, rbar, johnrusso, simoncook, sabuasal, niosHD, kito-cheng, shiva0217, MaskRay, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, psnobl, benna, Jim, s.egerton, pzheng, sameer.abuasal, apazos, luismarques, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D71978
* [RISCV] Support assembling %tls_{ie,gd}_pcrel_hi modifiersLewis Revill2019-04-231-0/+13
| | | | | | | | | This patch adds support for parsing and assembling the %tls_ie_pcrel_hi and %tls_gd_pcrel_hi modifiers. Differential Revision: https://reviews.llvm.org/D55342 llvm-svn: 358994
* [RISCV] Support assembling TLS add and associated modifiersLewis Revill2019-04-041-2/+56
| | | | | | | | | | This patch adds support in the MC layer for parsing and assembling the 4-operand add instruction needed for TLS addressing. This also involves parsing the %tprel_hi, %tprel_lo and %tprel_add operand modifiers. Differential Revision: https://reviews.llvm.org/D55341 llvm-svn: 357698
* [RISCV] Support assembling @plt symbol operandsAlex Bradbury2019-04-021-3/+8
| | | | | | | | | | This patch allows symbols appended with @plt to parse and assemble with the R_RISCV_CALL_PLT relocation. Differential Revision: https://reviews.llvm.org/D55335 Patch by Lewis Revill. llvm-svn: 357470
* [RISCV] Don't evaluatePCRelLo if a relocation will be forced (e.g. due to ↵Alex Bradbury2019-04-011-1/+13
| | | | | | | | | | | | | | | | | | linker relaxation) A pcrel_lo will point to the associated pcrel_hi fixup which in turn points to the real target. RISCVMCExpr::evaluatePCRelLo will work around this indirection in order to allow the fixup to be evaluate properly. However, if relocations are forced (e.g. due to linker relaxation is enabled) then its evaluation is undesired and will result in a relocation with the wrong target. This patch modifies evaluatePCRelLo so it will not try to evaluate if the fixup will be forced as a relocation. A new helper method is added to RISCVAsmBackend to query this. Differential Revision: https://reviews.llvm.org/D59686 llvm-svn: 357374
* [RISCV][MC] Find matching pcrel_hi fixup in more cases.Eli Friedman2019-03-121-4/+12
| | | | | | | | | | | | | | | | | If a symbol points to the end of a fragment, instead of searching for fixups in that fragment, search in the next fragment. Fixes spurious assembler error with subtarget change next to "la" pseudo-instruction, or expanded equivalent. Alternate proposal to fix the problem discussed in https://reviews.llvm.org/D58759. Testcase by Ana Pazos. Differential Revision: https://reviews.llvm.org/D58943 llvm-svn: 355946
* [RISCV] Support assembling %got_pcrel_hi operatorAlex Bradbury2019-02-151-1/+6
| | | | | | | Differential Revision: https://reviews.llvm.org/D55279 Patch by James Clarke. llvm-svn: 354110
* Update the file headers across all of the LLVM projects in the monorepoChandler Carruth2019-01-191-4/+3
| | | | | | | | | | | | | | | | | 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
* [RISCV] Properly evaluate fixup_riscv_pcrel_lo12Alex Bradbury2018-12-201-0/+82
| | | | | | | | | | | | | | | | | | | | This is a update to D43157 to correctly handle fixup_riscv_pcrel_lo12. Notable changes: Rebased onto trunk Handle and test S-type Test case pcrel-hilo.s is merged into relocations.s D43157 description: VK_RISCV_PCREL_LO has to be handled specially. The MCExpr inside is actually the location of an auipc instruction with a VK_RISCV_PCREL_HI fixup pointing to the real target. Differential Revision: https://reviews.llvm.org/D54029 Patch by Chih-Mao Chen and Michael Spencer. llvm-svn: 349764
* [Target] Untangle disassemblersBenjamin Kramer2018-09-101-1/+0
| | | | | | | Disassemblers cannot depend on main target headers. The same is true for MCTargetDesc, but there's a lot more cleanup needed for that. llvm-svn: 341822
* [RISCV] Add symbol diff relocation support for RISC-VAlex Bradbury2018-05-231-1/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For RISC-V it is desirable to have relaxation happen in the linker once addresses are known, and as such the size between two instructions/byte sequences in a section could change. For most assembler expressions, this is fine, as the absolute address results in the expression being converted to a fixup, and finally relocations. However, for expressions such as .quad .L2-.L1, the assembler folds this down to a constant once fragments are laid out, under the assumption that the difference can no longer change, although in the case of linker relaxation the differences can change at link time, so the constant is incorrect. One place where this commonly appears is in debug information, where the size of a function expression is in a form similar to the above. This patch extends the assembler to allow an AsmBackend to declare that it does not want the assembler to fold down this expression, and instead generate a pair of relocations that allow the linker to carry out the calculation. In this case, the expression is not folded, but when it comes to emitting a fixup, the generic FK_Data_* fixups are converted into a pair, one for the addition half, one for the subtraction, and this is passed to the relocation generating methods as usual. I have named these FK_Data_Add_* and FK_Data_Sub_* to indicate which half these are for. For RISC-V, which supports this via e.g. the R_RISCV_ADD64, R_RISCV_SUB64 pair of relocations, these are also set to always emit relocations relative to local symbols rather than section offsets. This is to deal with the fact that if relocations were calculated on e.g. .text+8 and .text+4, the result 12 would be stored rather than 4 as both addends are added in the linker. Differential Revision: https://reviews.llvm.org/D45181 Patch by Simon Cook. llvm-svn: 333079
* [RISCV] Support "call" pseudoinstruction in the MC layerShiva Chen2018-04-251-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | To do this: 1. Add PseudoCALLIndirct to match indirect function call. 2. Add PseudoCALL to support parsing and print pseudo `call` in assembly 3. Expand PseudoCALL to the following form with R_RISCV_CALL relocation type while encoding: auipc ra, func jalr ra, ra, 0 If we expand PseudoCALL before emitting assembly, we will see auipc and jalr pair when compile with -S. It's hard for assembly parser to parsing this pair and identify it's semantic is function call and then insert R_RISCV_CALL relocation type. Although we could insert R_RISCV_PCREL_HI20 and R_RISCV_PCREL_LO12_I relocation types instead of R_RISCV_CALL. Due to RISCV relocation design, auipc and jalr pair only can relax to jal with R_RISCV_CALL + R_RISCV_RELAX relocation types. We expand PseudoCALL as late as encoding(RISCVMCCodeEmitter) instead of before emitting assembly(RISCVAsmPrinter) because we want to preserve call pseudoinstruction in assembly code. It's more readable and assembly parser could identify call assembly and insert R_RISCV_CALL relocation type. Differential Revision: https://reviews.llvm.org/D45859 llvm-svn: 330826
* [RISCV] Tablegen-driven Instruction Compression.Sameer AbuAsal2018-04-061-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: This patch implements a tablegen-driven Instruction Compression mechanism for generating RISCV compressed instructions (C Extension) from the expanded instruction form. This tablegen backend processes CompressPat declarations in a td file and generates all the compile-time and runtime checks required to validate the declarations, validate the input operands and generate correct instructions. The checks include validating register operands, immediate operands, fixed register operands and fixed immediate operands. Example: class CompressPat<dag input, dag output> { dag Input = input; dag Output = output; list<Predicate> Predicates = []; } let Predicates = [HasStdExtC] in { def : CompressPat<(ADD GPRNoX0:$rs1, GPRNoX0:$rs1, GPRNoX0:$rs2), (C_ADD GPRNoX0:$rs1, GPRNoX0:$rs2)>; } The result is an auto-generated header file 'RISCVGenCompressEmitter.inc' which exports two functions for compressing/uncompressing MCInst instructions, plus some helper functions: bool compressInst(MCInst& OutInst, const MCInst &MI, const MCSubtargetInfo &STI, MCContext &Context); bool uncompressInst(MCInst& OutInst, const MCInst &MI, const MCRegisterInfo &MRI, const MCSubtargetInfo &STI); The clients that include this auto-generated header file and invoke these functions can compress an instruction before emitting it, in the target-specific ASM or ELF streamer, or can uncompress an instruction before printing it, when the expanded instruction format aliases is favored. The following clients were added to implement compression\uncompression for RISCV: 1) RISCVAsmParser::MatchAndEmitInstruction: Inserted a call to compressInst() to compresses instructions parsed by llvm-mc coming from an ASM input. 2) RISCVAsmPrinter::EmitInstruction: Inserted a call to compressInst() to compress instructions that were lowered from Machine Instructions (MachineInstr). 3) RVInstPrinter::printInst: Inserted a call to uncompressInst() to print the expanded version of the instruction instead of the compressed one (e.g, add s0, s0, a5 instead of c.add s0, a5) when -riscv-no-aliases is not passed. This patch squashes D45119, D42780 and D41932. It was reviewed in smaller patches by asb, efriedma, apazos and mgrang. Reviewers: asb, efriedma, apazos, llvm-commits, sabuasal Reviewed By: sabuasal Subscribers: mgorny, eraman, asb, rbar, johnrusso, simoncook, jordy.potman.lists, apazos, niosHD, kito-cheng, shiva0217, zzheng Differential Revision: https://reviews.llvm.org/D45385 llvm-svn: 329455
* [RISCV] Add support for %pcrel_lo.Ahmed Charles2018-02-061-1/+4
| | | | llvm-svn: 324303
* [RISCV] Add common fixups and relocationsAlex Bradbury2017-09-281-0/+99
%lo(), %hi(), and %pcrel_hi() are supported and test cases have been added to ensure the appropriate fixups and relocations are generated. I've added an instruction format field which is used in RISCVMCCodeEmitter to, for instance, tell whether it should emit a lo12_i fixup or a lo12_s fixup (RISC-V has two 12-bit immediate encodings depending on the instruction type). Differential Revision: https://reviews.llvm.org/D23568 llvm-svn: 314389
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