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* [RISCV] Fix evaluating %pcrel_lo against global and weak symbolsJames Clarke2020-01-231-3/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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] Support assembling %tls_{ie,gd}_pcrel_hi modifiersLewis Revill2019-04-231-0/+2
| | | | | | | | | 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 Revill2019-04-041-0/+4
| | | | | | | | | | 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 Bradbury2019-04-021-0/+1
| | | | | | | | | | 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/+8
| | | | | | | | | | | | | | | | | | 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] Add basic RV32E definitions and MC layer supportAlex Bradbury2019-03-221-0/+1
| | | | | | | | | | | | | | | | | | | | | The RISC-V ISA defines RV32E as an alternative "base" instruction set encoding, that differs from RV32I by having only 16 rather than 32 registers. This patch adds basic definitions for RV32E as well as MC layer support (assembling, disassembling) and tests. The only supported ABI on RV32E is ILP32E. Add a new RISCVFeatures::validate() helper to RISCVUtils which can be called from codegen or MC layer libraries to validate the combination of TargetTriple and FeatureBitSet. Other targets have similar checks (e.g. erroring if SPE is enabled on PPC64 or oddspreg + o32 ABI on Mips), but they either duplicate the checks (Mips), or fail to check for both codegen and MC codepaths (PPC). Codegen for the ILP32E ABI support and RV32E codegen are left for a future patch/patches. Differential Revision: https://reviews.llvm.org/D59470 llvm-svn: 356744
* [RISCV] Support -target-abi at the MC layer and for codegenAlex Bradbury2019-03-091-3/+13
| | | | | | | | | | | | | | | | This patch adds proper handling of -target-abi, as accepted by llvm-mc and llc. Lowering (codegen) for the hard-float ABIs will follow in a subsequent patch. However, this patch does add MC layer support for the hard float and RVE ABIs (emission of the appropriate ELF flags https://github.com/riscv/riscv-elf-psabi-doc/blob/master/riscv-elf.md#-file-header). ABI parsing must be shared between codegen and the MC layer, so we add computeTargetABI to RISCVUtils. A warning will be printed if an invalid or unrecognized ABI is given. Differential Revision: https://reviews.llvm.org/D59023 llvm-svn: 355771
* [RISCV] Support assembling %got_pcrel_hi operatorAlex Bradbury2019-02-151-0/+1
| | | | | | | Differential Revision: https://reviews.llvm.org/D55279 Patch by James Clarke. llvm-svn: 354110
* [RISCV] Insert R_RISCV_ALIGN relocation type and Nops for code alignment ↵Shiva Chen2019-01-301-1/+12
| | | | | | | | | | | | | | | | | | | | when linker relaxation enabled Linker relaxation may change code size. We need to fix up the alignment of alignment directive in text section by inserting Nops and R_RISCV_ALIGN relocation type. So then linker could satisfy the alignment by removing Nops. To do this: 1. Add shouldInsertExtraNopBytesForCodeAlign target hook to calculate the Nops we need to insert. 2. Add shouldInsertFixupForCodeAlign target hook to insert R_RISCV_ALIGN fixup type. Differential Revision: https://reviews.llvm.org/D47755 llvm-svn: 352616
* 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 Bradbury2018-12-201-6/+1
| | | | | | | | | | | | | | | | | | | | 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
* [RISCV] Support .option relax and .option norelaxAlex Bradbury2018-11-121-0/+118
This extends the .option support from D45864 to enable/disable the relax feature flag from D44886 During parsing of the relax/norelax directives, the RISCV::FeatureRelax feature bits of the SubtargetInfo stored in the AsmParser are updated appropriately to reflect whether relaxation is currently enabled in the parser. When an instruction is parsed, the parser checks if relaxation is currently enabled and if so, gets a handle to the AsmBackend and sets the ForceRelocs flag. The AsmBackend uses a combination of the original RISCV::FeatureRelax feature bits set by e.g -mattr=+/-relax and the ForceRelocs flag to determine whether to emit relocations for symbol and branch diffs. Diff relocations should therefore only not be emitted if the relax flag was not set on the command line and no instruction was ever parsed in a section with relaxation enabled to ensure correct diffs are emitted. Differential Revision: https://reviews.llvm.org/D46423 Patch by Lewis Revill. llvm-svn: 346655
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