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* bpf: remove unnecessary truncate operationYonghong Song2017-06-291-77/+235
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For networking-type bpf program, it often needs to access packet data. A context data structure is provided to the bpf programs with two fields: u32 data; u32 data_end; User can access these two fields with ctx->data and ctx->data_end. During program verification process, the kernel verifier modifies the bpf program with loading of actual pointer value from kernel data structure. r = ctx->data ===> r = actual data start ptr r = ctx->data_end ===> r = actual data end ptr A typical program accessing ctx->data like char *data_ptr = (char *)(long)ctx->data will result in a 32-bit load followed by a zero extension. Such an operation is combined into a single LDW in DAG combiner as bpf LDW does zero extension automatically. In cases like the below (which can be a result of global value numbering and partial redundancy elimination before insn selection): B1: u32 a = load-32-bit &ctx->data u64 pa = zext a ... B2: u32 b = load-32-bit &ctx->data u64 pb = zext b ... B3: u32 m = PHI(a, b) u64 pm = zext m In B3, "pm = zext m" cannot be removed, which although is legal from compiler perspective, will generate incorrect code after kernel verification. This patch recognizes this pattern and traces through PHI node to see whether the operand of "zext m" is defined with LDWs or not. If it is, the "zext m" itself can be removed. The patch also recognizes the pattern where the load and use of the load value not in the same basic block, where truncate operation may be removed as well. The patch handles 1-byte, 2-byte and 4-byte truncation. Two test cases are added to verify the transformation happens properly for the above code pattern. Signed-off-by: Yonghong Song <yhs@fb.com> llvm-svn: 306685
* Remove redundant argument.Rafael Espindola2017-06-241-2/+2
| | | | llvm-svn: 306189
* ARM: move some logic from processFixupValue to applyFixup.Rafael Espindola2017-06-231-4/+6
| | | | | | | | | | | | processFixupValue is called on every relaxation iteration. applyFixup is only called once at the very end. applyFixup is then the correct place to do last minute changes and value checks. While here, do proper range checks again for fixup_arm_thumb_bl. We used to do it, but dropped because of thumb2. We now do it again, but use the thumb2 range. llvm-svn: 306177
* Use a MutableArrayRef. NFC.Rafael Espindola2017-06-211-3/+3
| | | | llvm-svn: 305968
* bpf: fix a strict-aliasing issueYonghong Song2017-06-161-11/+19
| | | | | | | | | | | | | | | | | | | | | | Davide Italiano reported the following issue if llvm is compiled with gcc -Wstrict-aliasing -Werror: ..... lib/Target/BPF/CMakeFiles/LLVMBPFCodeGen.dir/BPFISelDAGToDAG.cpp.o ../lib/Target/BPF/BPFISelDAGToDAG.cpp: In member function ‘virtual void {anonymous}::BPFDAGToDAGISel::PreprocessISelDAG()’: ../lib/Target/BPF/BPFISelDAGToDAG.cpp:264:26: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing] val = *(uint16_t *)new_val; ..... The error is caused by my previous commit (revision 305560). This patch fixed the issue by introducing an union to avoid type casting. Signed-off-by: Yonghong Song <yhs@fb.com> llvm-svn: 305608
* bpf: avoid load from read-only sectionsYonghong Song2017-06-161-7/+233
| | | | | | | | | | | | | | | | | | | | | | | | | | | If users tried to have a structure decl/init code like below struct test_t t = { .memeber1 = 45 }; It is very likely that compiler will generate a readonly section to hold up the init values for variable t. Later load of t members, e.g., t.member1 will result in a read from readonly section. BPF program cannot handle relocation. This will force users to write: struct test_t t = {}; t.member1 = 45; This is just inconvenient and unintuitive. This patch addresses this issue by implementing BPF PreprocessISelDAG. For any load from a global constant structure or an global array of constant struct, it attempts to translate it into a constant directly. The traversal of the constant struct and other constant data structures are similar to where the assembler emits read-only sections. Four different unit test cases are also added to cover different scenarios. Signed-off-by: Yonghong Song <yhs@fb.com> llvm-svn: 305560
* bpf: set missing types in insn tablegen fileYonghong Song2017-06-161-7/+7
| | | | | | | | | | | | o This is discovered during my study of 32-bit subregister support. o This is no impact on current functionality since we only support 64-bit registers. o Searching the web, looks like the issue has been discovered before, so fix it now. Signed-off-by: Yonghong Song <yhs@fb.com> llvm-svn: 305559
* bpf: clang-format on BPFAsmPrinter.cppYonghong Song2017-06-131-2/+3
| | | | | Signed-off-by: Yonghong Song <yhs@fb.com> llvm-svn: 305301
* Move Object format code to lib/BinaryFormat.Zachary Turner2017-06-071-1/+1
| | | | | | | | | | | | This creates a new library called BinaryFormat that has all of the headers from llvm/Support containing structure and layout definitions for various types of binary formats like dwarf, coff, elf, etc as well as the code for identifying a file from its magic. Differential Revision: https://reviews.llvm.org/D33843 llvm-svn: 304864
* Sort the remaining #include lines in include/... and lib/....Chandler Carruth2017-06-068-14/+14
| | | | | | | | | | | | | | | | | | | | | | | | | I did this a long time ago with a janky python script, but now clang-format has built-in support for this. I fed clang-format every line with a #include and let it re-sort things according to the precise LLVM rules for include ordering baked into clang-format these days. I've reverted a number of files where the results of sorting includes isn't healthy. Either places where we have legacy code relying on particular include ordering (where possible, I'll fix these separately) or where we have particular formatting around #include lines that I didn't want to disturb in this patch. This patch is *entirely* mechanical. If you get merge conflicts or anything, just ignore the changes in this patch and run clang-format over your #include lines in the files. Sorry for any noise here, but it is important to keep these things stable. I was seeing an increasing number of patches with irrelevant re-ordering of #include lines because clang-format was used. This patch at least isolates that churn, makes it easy to skip when resolving conflicts, and gets us to a clean baseline (again). llvm-svn: 304787
* [BPF] Correct the file name of the -gen-asm-matcher output file to not start ↵Craig Topper2017-05-311-1/+1
| | | | | | with X86. llvm-svn: 304324
* TargetPassConfig: Keep a reference to an LLVMTargetMachine; NFCMatthias Braun2017-05-301-2/+2
| | | | | | | | | | | TargetPassConfig is not useful for targets that do not use the CodeGen library, so we may just as well store a pointer to an LLVMTargetMachine instead of just to a TargetMachine. While at it, also change the constructor to take a reference instead of a pointer as the TM must not be nullptr. llvm-svn: 304247
* [bpf] disallow global_addr+off foldingAlexei Starovoitov2017-05-262-1/+12
| | | | | | | | | | | | | | | | | | | | | | | | | Wrong assembly code is generated for a simple program with clang. If clang only produces IR and llc is used for IR lowering and optimization, correct assembly code is generated. The main reason is that clang feeds default Reloc::Static to llvm and llc feeds no RelocMode to llvm, where for llc case, BPF backend picks up Reloc::PIC_ mode. This leads different IR lowering behavior and clang permits global_addr+off folding while llc doesn't. This patch introduces isOffsetFoldingLegal function into BPF backend and the function always return false. This will make clang and llc behave the same for the lowering. Bug https://bugs.llvm.org//show_bug.cgi?id=33183 has more detailed explanation. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> llvm-svn: 304043
* Add extra operand to CALLSEQ_START to keep frame part set up previouslySerge Pavlov2017-05-092-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using arguments with attribute inalloca creates problems for verification of machine representation. This attribute instructs the backend that the argument is prepared in stack prior to CALLSEQ_START..CALLSEQ_END sequence (see http://llvm.org/docs/InAlloca.htm for details). Frame size stored in CALLSEQ_START in this case does not count the size of this argument. However CALLSEQ_END still keeps total frame size, as caller can be responsible for cleanup of entire frame. So CALLSEQ_START and CALLSEQ_END keep different frame size and the difference is treated by MachineVerifier as stack error. Currently there is no way to distinguish this case from actual errors. This patch adds additional argument to CALLSEQ_START and its target-specific counterparts to keep size of stack that is set up prior to the call frame sequence. This argument allows MachineVerifier to calculate actual frame size associated with frame setup instruction and correctly process the case of inalloca arguments. The changes made by the patch are: - Frame setup instructions get the second mandatory argument. It affects all targets that use frame pseudo instructions and touched many files although the changes are uniform. - Access to frame properties are implemented using special instructions rather than calls getOperand(N).getImm(). For X86 and ARM such replacement was made previously. - Changes that reflect appearance of additional argument of frame setup instruction. These involve proper instruction initialization and methods that access instruction arguments. - MachineVerifier retrieves frame size using method, which reports sum of frame parts initialized inside frame instruction pair and outside it. The patch implements approach proposed by Quentin Colombet in https://bugs.llvm.org/show_bug.cgi?id=27481#c1. It fixes 9 tests failed with machine verifier enabled and listed in PR27481. Differential Revision: https://reviews.llvm.org/D32394 llvm-svn: 302527
* [bpf] fix a bug which causes incorrect big endian reloc fixupAlexei Starovoitov2017-05-051-1/+1
| | | | | | | | o Add bpfeb support in BPF dwarfdump unit test case Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@fb.com> llvm-svn: 302265
* [bpf] add bigendian support to disassemblerAlexei Starovoitov2017-04-281-7/+19
| | | | | | | | | . swap 4-bit register encoding, 16-bit offset and 32-bit imm to support big endian archs . add a test Reported-by: David S. Miller <davem@davemloft.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> llvm-svn: 301653
* Distinguish between code pointer size and DataLayout::getPointerSize() in ↵Konstantin Zhuravlyov2017-04-171-1/+1
| | | | | | DWARF info generation llvm-svn: 300463
* [bpf] Fix memory offset check for loads and storesAlexei Starovoitov2017-04-131-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the offset cannot fit into the instruction, an addition to the pointer is emitted before the actual access. However, BPF offsets are 16-bit but LLVM considers them to be, for the matter of this check, to be 32-bit long. This causes the following program: int bpf_prog1(void *ign) { volatile unsigned long t = 0x8983984739ull; return *(unsigned long *)((0xffffffff8fff0002ull) + t); } To generate the following (wrong) code: 0: 18 01 00 00 39 47 98 83 00 00 00 00 89 00 00 00 r1 = 590618314553ll 2: 7b 1a f8 ff 00 00 00 00 *(u64 *)(r10 - 8) = r1 3: 79 a1 f8 ff 00 00 00 00 r1 = *(u64 *)(r10 - 8) 4: 79 10 02 00 00 00 00 00 r0 = *(u64 *)(r1 + 2) 5: 95 00 00 00 00 00 00 00 exit Fix it by changing the offset check to 16-bit. Patch by Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Differential Revision: https://reviews.llvm.org/D32055 llvm-svn: 300269
* Add MCContext argument to MCAsmBackend::applyFixup for error reportingAlex Bradbury2017-04-051-3/+3
| | | | | | | | | | | | | | | | A number of backends (AArch64, MIPS, ARM) have been using MCContext::reportError to report issues such as out-of-range fixup values in their TgtAsmBackend. This is great, but because MCContext couldn't easily be threaded through to the adjustFixupValue helper function from its usual callsite (applyFixup), these backends ended up adding an MCContext* argument and adding another call to applyFixup to processFixupValue. Adding an MCContext parameter to applyFixup makes this unnecessary, and even better - applyFixup can take a reference to MCContext rather than a potentially null pointer. Differential Revision: https://reviews.llvm.org/D30264 llvm-svn: 299529
* Cleanup dump() functions.Matthias Braun2017-01-282-2/+2
| | | | | | | | | | | | | | | | | | We had various variants of defining dump() functions in LLVM. Normalize them (this should just consistently implement the things discussed in http://lists.llvm.org/pipermail/cfe-dev/2014-January/034323.html For reference: - Public headers should just declare the dump() method but not use LLVM_DUMP_METHOD or #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) - The definition of a dump method should look like this: #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) LLVM_DUMP_METHOD void MyClass::dump() { // print stuff to dbgs()... } #endif llvm-svn: 293359
* [bpf] fix stack-use-after-scopeAlexei Starovoitov2017-01-171-7/+7
| | | | | Signed-off-by: Alexei Starovoitov <ast@kernel.org> llvm-svn: 292258
* [bpf] error when unknown bpf helper is calledAlexei Starovoitov2017-01-174-3/+25
| | | | | | | | | | Emit error when BPF backend sees a call to a global function or to an external symbol. The kernel verifier only allows calls to predefined helpers from bpf.h which are defined in 'enum bpf_func_id'. Such calls in assembler must look like 'call [1-9]+' where number matches bpf_func_id. Signed-off-by: Alexei Starovoitov <ast@kernel.org> llvm-svn: 292204
* [bpf] error when BPF stack size exceeds 512 bytesAlexei Starovoitov2017-01-171-2/+26
| | | | | Signed-off-by: Alexei Starovoitov <ast@kernel.org> llvm-svn: 292180
* [BPF] Fix some Clang-tidy modernize and Include What You Use warnings; other ↵Eugene Zelenko2017-01-066-45/+42
| | | | | | minor fixes (NFC). llvm-svn: 291297
* [bpf] fix dwarf elf relocs and line numbersAlexei Starovoitov2016-11-212-4/+13
| | | | | | | | | - teach RelocVisitor to recognize bpf relocations - fix AsmInfo->PointerSize to make sure dwarf is emitted correctly - add a test for the above Signed-off-by: Alexei Starovoitov <ast@kernel.org> llvm-svn: 287521
* [bpf] add BPF disassemblerAlexei Starovoitov2016-11-206-3/+195
| | | | | | | | | | | | | | | | | | | | | | | | | | add BPF disassembler, so tools like llvm-objdump can be used: $ llvm-objdump -d -no-show-raw-insn ./sockex1_kern.o ./sockex1_kern.o: file format ELF64-BPF Disassembly of section socket1: bpf_prog1: 0: r6 = r1 8: r0 = *(u8 *)skb[23] 10: *(u32 *)(r10 - 4) = r0 18: r1 = *(u32 *)(r6 + 4) 20: if r1 != 4 goto 8 28: r2 = r10 30: r2 += -4 ld_imm64 (the only 16-byte insn) and special ld_abs/ld_ind instructions had to be treated in a special way. The decoders for the rest of the insns are automatically generated. Add tests to cover new functionality. Signed-off-by: Alexei Starovoitov <ast@kernel.org> llvm-svn: 287477
* Try again to fix unused variable warning on lld-x86_64-darwin13 after r287439.Daniel Sanders2016-11-191-2/+1
| | | | | | | The previous attempt didn't work. I assume LLVM_ATTRIBUTE_UNUSED isn't available on that machine. llvm-svn: 287442
* Try to fix unused variable warning on lld-x86_64-darwin13 after r287439.Daniel Sanders2016-11-191-1/+2
| | | | | | Whether the variable is used or not depends on NDEBUG. llvm-svn: 287440
* Check that emitted instructions meet their predicates on all targets except ↵Daniel Sanders2016-11-191-4/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | ARM, Mips, and X86. Summary: * ARM is omitted from this patch because this check appears to expose bugs in this target. * Mips is omitted from this patch because this check either detects bugs or deliberate emission of instructions that don't satisfy their predicates. One deliberate use is the SYNC instruction where the version with an operand is correctly defined as requiring MIPS32 while the version without an operand is defined as an alias of 'SYNC 0' and requires MIPS2. * X86 is omitted from this patch because it doesn't use the tablegen-erated MCCodeEmitter infrastructure. Patches for ARM and Mips will follow. Depends on D25617 Reviewers: tstellarAMD, jmolloy Subscribers: wdng, jmolloy, aemerson, rengolin, arsenm, jyknight, nemanjai, nhaehnle, tstellarAMD, llvm-commits Differential Revision: https://reviews.llvm.org/D25618 llvm-svn: 287439
* convert bpf assembler to look like kernel verifier outputAlexei Starovoitov2016-11-183-57/+69
| | | | | | | | | | since bpf instruction set was introduced people learned to read and understand kernel verifier output whereas llvm asm output stayed obscure and unknown. Convert llvm to emit assembler text similar to kernel to avoid this discrepancy Signed-off-by: Alexei Starovoitov <ast@kernel.org> llvm-svn: 287300
* Move the global variables representing each Target behind accessor functionMehdi Amini2016-10-095-27/+44
| | | | | | | | This avoids "static initialization order fiasco" Differential Revision: https://reviews.llvm.org/D25412 llvm-svn: 283702
* Use StringRef in Pass/PassManager APIs (NFC)Mehdi Amini2016-10-012-2/+2
| | | | llvm-svn: 283004
* Finish renaming remaining analyzeBranch functionsMatt Arsenault2016-09-142-2/+2
| | | | llvm-svn: 281535
* Make analyzeBranch family of instruction names consistentMatt Arsenault2016-09-142-3/+3
| | | | | | | analyzeBranch was renamed to use lowercase first, rename the related set to match. llvm-svn: 281506
* AArch64: Use TTI branch functions in branch relaxationMatt Arsenault2016-09-142-4/+12
| | | | | | | | | The main change is to return the code size from InsertBranch/RemoveBranch. Patch mostly by Tim Northover llvm-svn: 281505
* MachineFunction: Return reference for getFrameInfo(); NFCMatthias Braun2016-07-281-2/+2
| | | | | | | getFrameInfo() never returns nullptr so we should use a reference instead of a pointer. llvm-svn: 277017
* MC] Provide an MCTargetOptions to implementors of MCAsmBackendCtorTy, NFCJoel Jones2016-07-252-4/+9
| | | | | | | | | | | | | | | Some targets, notably AArch64 for ILP32, have different relocation encodings based upon the ABI. This is an enabling change, so a future patch can use the ABIName from MCTargetOptions to chose which relocations to use. Tested using check-llvm. The corresponding change to clang is in: http://reviews.llvm.org/D16538 Patch by: Joel Jones Differential Revision: https://reviews.llvm.org/D16213 llvm-svn: 276654
* BPF: Use official ELF e_machine valueAlexei Starovoitov2016-07-151-1/+1
| | | | | | | | | The same value for EM_BPF is being propagated to glibc, elfutils, and binutils. Signed-off-by: Richard Henderson <rth@twiddle.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> llvm-svn: 275633
* Rename AnalyzeBranch* to analyzeBranch*.Jacques Pienaar2016-07-152-2/+2
| | | | | | | | | | | | Summary: NFC. Rename AnalyzeBranch/AnalyzeBranchPredicate to analyzeBranch/analyzeBranchPredicate to follow LLVM coding style and be consistent with TargetInstrInfo's analyzeCompare and analyzeSelect. Reviewers: tstellarAMD, mcrosier Subscribers: mcrosier, jholewinski, jfb, arsenm, dschuff, jyknight, dsanders, nemanjai Differential Revision: https://reviews.llvm.org/D22409 llvm-svn: 275564
* Fix branch relaxation in 16-bit mode.Nirav Dave2016-07-111-1/+2
| | | | | | | | | | | | | | | Thread through MCSubtargetInfo to relaxInstruction function allowing relaxation to generate jumps with 16-bit sized immediates in 16-bit mode. This fixes PR22097. Reviewers: dwmw2, tstellarAMD, craig.topper, jyknight Subscribers: jfb, arsenm, jyknight, llvm-commits, dsanders Differential Revision: http://reviews.llvm.org/D20830 llvm-svn: 275068
* CodeGen: Use MachineInstr& in TargetLowering, NFCDuncan P. N. Exon Smith2016-06-302-11/+11
| | | | | | | | | | | | | This is a mechanical change to make TargetLowering API take MachineInstr& (instead of MachineInstr*), since the argument is expected to be a valid MachineInstr. In one case, changed a parameter from MachineInstr* to MachineBasicBlock::iterator, since it was used as an insertion point. As a side effect, this removes a bunch of MachineInstr* to MachineBasicBlock::iterator implicit conversions, a necessary step toward fixing PR26753. llvm-svn: 274287
* Delete MCCodeGenInfo.Rafael Espindola2016-06-301-12/+0
| | | | | | | MC doesn't really care about CodeGen stuff, so this was just complicating target initialization. llvm-svn: 274258
* Prune some includes from headers and sink some inline functionsReid Kleckner2016-06-221-0/+1
| | | | | | | | MCSymbol.h shouldn't pull in MCAssembler.h, just MCFragment.h. MCLinkerOptimizationHint.h shouldn't need MCMachObjectWriter.h. The rest is fixing the fallout. llvm-svn: 273507
* Delete more dead code.Rafael Espindola2016-06-221-28/+0
| | | | | | Found by gcc 6. llvm-svn: 273402
* Pass DebugLoc and SDLoc by const ref.Benjamin Kramer2016-06-124-17/+18
| | | | | | | | This used to be free, copying and moving DebugLocs became expensive after the metadata rewrite. Passing by reference eliminates a ton of track/untrack operations. No functionality change intended. llvm-svn: 272512
* [BPF] Remove exit-on-error from tests (PR27768, PR27769)Diana Picus2016-05-301-1/+5
| | | | | | | | | | | The exit-on-error flag is necessary to avoid some assertions/unreachables. We can get past them by creating a few dummy nodes. Fixes PR27768, PR27769. Differential Revision: http://reviews.llvm.org/D20726 llvm-svn: 271200
* [BPF] Remove exit-on-error flag in test (PR27767)Diana Picus2016-05-261-0/+1
| | | | | | | | | | | | The exit-on-error flag is needed to avoid an assert where llvm::SelectionDAGISel::LowerArguments doesn't create enough arguments. Fill up with zeroes to reach the right number of args. Fixes PR27767. Differential Revision: http://reviews.llvm.org/D20571 llvm-svn: 270855
* [BPF] Remove exit-on-error flag in test (PR27766)Diana Picus2016-05-232-4/+10
| | | | | | | | | | | | | | The exit-on-error flag on the many_args1.ll test is needed to avoid an unreachable in BPFTargetLowering::LowerCall. We can also avoid it by ignoring any superfluous arguments to the call (i.e. any arguments after the first 5). Fixes PR27766. Differential Revision: http://reviews.llvm.org/D20471 v2 of r270419 llvm-svn: 270440
* Reverts "[BPF] Remove exit-on-error flag in test (PR27766)"Renato Golin2016-05-232-8/+4
| | | | | | | | This patch reverts r270419 because it broke a lot of buildbots, mostly Windows. We'd like help in investigating the issues, but for now, it should stay out. llvm-svn: 270433
* [BPF] Remove exit-on-error flag in test (PR27766)Diana Picus2016-05-232-4/+8
| | | | | | | | | | The exit-on-error flag on the many_args1.ll test is needed to avoid an unreachable in BPFTargetLowering::LowerCall. We can also avoid it by ignoring any superfluous arguments to the call (i.e. any arguments after the first 5). Fixes PR27766 llvm-svn: 270419
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