summaryrefslogtreecommitdiffstats
path: root/llvm/lib/Target/BPF/BPFSubtarget.h
Commit message (Collapse)AuthorAgeFilesLines
* [BPF] add code-gen support for JMP32 instructionsJiong Wang2019-02-071-0/+5
| | | | | | | | | | | | | | | | | | | | | | | JMP32 instructions has been added to eBPF ISA. They are 32-bit variants of existing BPF conditional jump instructions, but the comparison happens on low 32-bit sub-register only, therefore some unnecessary extensions could be saved. JMP32 instructions will only be available for -mcpu=v3. Host probe hook has been updated accordingly. JMP32 instructions will only be enabled in code-gen when -mattr=+alu32 enabled, meaning compiling the program using sub-register mode. For JMP32 encoding, it is a new instruction class, and is using the reserved eBPF class number 0x6. This patch has been tested by compiling and running kernel bpf selftests with JMP32 enabled. Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Jiong Wang <jiong.wang@netronome.com> llvm-svn: 353384
* 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
* bpf: new option -bpf-expand-memcpy-in-order to expand memcpy in orderYonghong Song2018-07-251-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Some BPF JIT backends would want to optimize memcpy in their own architecture specific way. However, at the moment, there is no way for JIT backends to see memcpy semantics in a reliable way. This is due to LLVM BPF backend is expanding memcpy into load/store sequences and could possibly schedule them apart from each other further. So, BPF JIT backends inside kernel can't reliably recognize memcpy semantics by peephole BPF sequence. This patch introduce new intrinsic expand infrastructure to memcpy. To get stable in-order load/store sequence from memcpy, we first lower memcpy into BPF::MEMCPY node which then expanded into in-order load/store sequences in expandPostRAPseudo pass which will happen after instruction scheduling. By this way, kernel JIT backends could reliably recognize memcpy through scanning BPF sequence. This new memcpy expand infrastructure is gated by a new option: -bpf-expand-memcpy-in-order Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Yonghong Song <yhs@fb.com> llvm-svn: 337977
* bpf: introduce -mattr=dwarfris to disable DwarfUsesRelocationsAcrossSectionsYonghong Song2018-03-011-0/+4
| | | | | | | | | | | | | | | | | | | | | Commit e4507fb8c94b ("bpf: disable DwarfUsesRelocationsAcrossSections") disables MCAsmInfo DwarfUsesRelocationsAcrossSections unconditionally so that dwarf will not use cross section (between dwarf and symbol table) relocations. This new debug format enables pahole to dump structures correctly as libdwarves.so does not have BPF backend support yet. This new debug format, however, breaks bcc (https://github.com/iovisor/bcc) source debug output as llvm in-memory Dwarf support has some issues to handle it. More specifically, with DwarfUsesRelocationsAcrossSections disabled, JIT compiler does not generate .debug_abbrev and Dwarf DIE (debug info entry) processing is not happy about this. This patch introduces a new flag -mattr=dwarfris (dwarf relocation in section) to disable DwarfUsesRelocationsAcrossSections. DwarfUsesRelocationsAcrossSections is true by default. Signed-off-by: Yonghong Song <yhs@fb.com> llvm-svn: 326505
* bpf: New target attribute "alu32" for 32-bit subregister supportYonghong Song2018-02-231-0/+4
| | | | | | | | | | | | | | | | | | This new attribute aims to control the enablement of 32-bit subregister support on eBPF backend. Name the interface as "alu32" is because we in particular want to enable the generation of BPF_ALU32 instructions by enable subregister support. This attribute could be used in the following format with llc: llc -mtriple=bpf -mattr=[+|-]alu32 It is disabled at default. Signed-off-by: Jiong Wang <jiong.wang@netronome.com> Reviewed-by: Yonghong Song <yhs@fb.com> llvm-svn: 325982
* Fix a bunch more layering of CodeGen headers that are in TargetDavid Blaikie2017-11-171-1/+1
| | | | | | | | 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
* bpf: add variants of -mcpu=# and support for additional jmp insnsYonghong Song2017-08-231-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | -mcpu=# will support: . generic: the default insn set . v1: insn set version 1, the same as generic . v2: insn set version 2, version 1 + additional jmp insns . probe: the compiler will probe the underlying kernel to decide proper version of insn set. We did not not use -mcpu=native since llc/llvm will interpret -mcpu=native as the underlying hardware architecture regardless of -march value. Currently, only x86_64 supports -mcpu=probe. Other architecture will silently revert to "generic". Also added -mcpu=help to print available cpu parameters. llvm will print out the information only if there are at least one cpu and at least one feature. Add an unused dummy feature to enable the printout. Examples for usage: $ llc -march=bpf -mcpu=v1 -filetype=asm t.ll $ llc -march=bpf -mcpu=v2 -filetype=asm t.ll $ llc -march=bpf -mcpu=generic -filetype=asm t.ll $ llc -march=bpf -mcpu=probe -filetype=asm t.ll $ llc -march=bpf -mcpu=v3 -filetype=asm t.ll 'v3' is not a recognized processor for this target (ignoring processor) ... $ llc -march=bpf -mcpu=help -filetype=asm t.ll Available CPUs for this target: generic - Select the generic processor. probe - Select the probe processor. v1 - Select the v1 processor. v2 - Select the v2 processor. Available features for this target: dummy - unused feature. Use +feature to enable a feature, or -feature to disable it. For example, llc -mcpu=mycpu -mattr=+feature1,-feature2 ... Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Yonghong Song <yhs@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> llvm-svn: 311522
* Rename TargetSelectionDAGInfo into SelectionDAGTargetInfo and move it to ↵Benjamin Kramer2016-01-271-3/+3
| | | | | | | | CodeGen/ It's a SelectionDAG thing, not a Target thing. llvm-svn: 258939
* 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
* 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
* Replace string GNU Triples with llvm::Triple in MCSubtargetInfo and ↵Daniel Sanders2015-06-101-2/+2
| | | | | | | | | | | | | | | | | | create*MCSubtargetInfo(). NFC. Summary: This continues the patch series to eliminate StringRef forms of GNU triples from the internals of LLVM that began in r239036. Reviewers: rafael Reviewed By: rafael Subscribers: rafael, ted, jfb, llvm-commits, rengolin, jholewinski Differential Revision: http://reviews.llvm.org/D10311 llvm-svn: 239467
* bpf: fix build due to 'Move DataLayout back to the TargetMachine'Alexei Starovoitov2015-01-261-2/+0
| | | | | | commit r227113 moved DataLayout llvm-svn: 227133
* BPF backendAlexei Starovoitov2015-01-241-0/+66
Summary: V8->V9: - cleanup tests V7->V8: - addressed feedback from David: - switched to range-based 'for' loops - fixed formatting of tests V6->V7: - rebased and adjusted AsmPrinter args - CamelCased .td, fixed formatting, cleaned up names, removed unused patterns - diffstat: 3 files changed, 203 insertions(+), 227 deletions(-) V5->V6: - addressed feedback from Chandler: - reinstated full verbose standard banner in all files - fixed variables that were not in CamelCase - fixed names of #ifdef in header files - removed redundant braces in if/else chains with single statements - fixed comments - removed trailing empty line - dropped debug annotations from tests - diffstat of these changes: 46 files changed, 456 insertions(+), 469 deletions(-) V4->V5: - fix setLoadExtAction() interface - clang-formated all where it made sense V3->V4: - added CODE_OWNERS entry for BPF backend V2->V3: - fix metadata in tests V1->V2: - addressed feedback from Tom and Matt - removed top level change to configure (now everything via 'experimental-backend') - reworked error reporting via DiagnosticInfo (similar to R600) - added few more tests - added cmake build - added Triple::bpf - tested on linux and darwin V1 cover letter: --------------------- recently linux gained "universal in-kernel virtual machine" which is called eBPF or extended BPF. The name comes from "Berkeley Packet Filter", since new instruction set is based on it. This patch adds a new backend that emits extended BPF instruction set. The concept and development are covered by the following articles: http://lwn.net/Articles/599755/ http://lwn.net/Articles/575531/ http://lwn.net/Articles/603983/ http://lwn.net/Articles/606089/ http://lwn.net/Articles/612878/ One of use cases: dtrace/systemtap alternative. bpf syscall manpage: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=b4fc1a460f3017e958e6a8ea560ea0afd91bf6fe instruction set description and differences vs classic BPF: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/networking/filter.txt Short summary of instruction set: - 64-bit registers R0 - return value from in-kernel function, and exit value for BPF program R1 - R5 - arguments from BPF program to in-kernel function R6 - R9 - callee saved registers that in-kernel function will preserve R10 - read-only frame pointer to access stack - two-operand instructions like +, -, *, mov, load/store - implicit prologue/epilogue (invisible stack pointer) - no floating point, no simd Short history of extended BPF in kernel: interpreter in 3.15, x64 JIT in 3.16, arm64 JIT, verifier, bpf syscall in 3.18, more to come in the future. It's a very small and simple backend. There is no support for global variables, arbitrary function calls, floating point, varargs, exceptions, indirect jumps, arbitrary pointer arithmetic, alloca, etc. From C front-end point of view it's very restricted. It's done on purpose, since kernel rejects all programs that it cannot prove safe. It rejects programs with loops and with memory accesses via arbitrary pointers. When kernel accepts the program it is guaranteed that program will terminate and will not crash the kernel. This patch implements all 'must have' bits. There are several things on TODO list, so this is not the end of development. Most of the code is a boiler plate code, copy-pasted from other backends. Only odd things are lack or < and <= instructions, specialized load_byte intrinsics and 'compare and goto' as single instruction. Current instruction set is fixed, but more instructions can be added in the future. Signed-off-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> Subscribers: majnemer, chandlerc, echristo, joerg, pete, rengolin, kristof.beyls, arsenm, t.p.northover, tstellarAMD, aemerson, llvm-commits Differential Revision: http://reviews.llvm.org/D6494 llvm-svn: 227008
OpenPOWER on IntegriCloud